NASA Astrophysics Data System (ADS)
Yu, Dapeng; Guan, Mingfu; Wilby, Robert; Bruce, Wright; Szegner, Mark
2017-04-01
Emergency services (such as Fire & Rescue, and Ambulance) can face the challenging tasks of having to respond to or operate under extreme and fast changing weather conditions, including surface water flooding. UK-wide, return period based surface water flood risk mapping undertaken by the Environment Agency provides useful information about areas at risks. Although these maps are useful for planning purposes for emergency responders, their utility to operational response during flood emergencies can be limited. A street-level, high resolution, real-time, surface water flood nowcasting system, has been piloted in the City of Leicester, UK to assess emergency response resilience to surface water flooding. Precipitation nowcasting over 7- and 48-hour horizons are obtained from the UK Met Office and used as inputs to the system. A hydro-inundation model is used to simulate urban surface water flood depths/areas at both the city and basin scale, with a 20 m and 3 m spatial resolution respectively, and a 15-minute temporal resolution, 7-hour and 48-hour in advance. Based on this, we evaluate both the direct and indirect impacts of potential surface water flood events on emergency responses, including: (i) identifying vulnerable populations (e.g. care homes and schools) at risk; and (ii) generating novel metrics of accessibility (e.g. travel time from service stations to vulnerable sites; spatial coverage with certain legislative timeframes) in real-time. In doing so, real-time information on potential risks and impacts of emerging flood incidents arising from intense rainfall can be communicated via a dedicated web-based platform to emergency responders thereby improving response times and operational resilience.
NASA Astrophysics Data System (ADS)
Asfaw, Alemayehu; Shucksmith, James; Smith, Andrea; Cherry, Katherine
2015-04-01
Metaldehyde is an active ingredient in agricultural pesticides such as slug pellets, which are heavily applied to UK farmland during the autumn application season. There is current concern that existing drinking water treatment processes may be inadequate in reducing potentially high levels of metaldehyde in surface waters to below the UK drinking water quality regulation limit of 0.1 µg/l. In addition, current water quality monitoring methods can miss short term fluctuations in metaldehyde concentration caused by rainfall driven runoff, hampering prediction of the potential risk of exposure. Datasets describing levels, fate and transport of metaldehyde in river catchments are currently very scarce. This work presents results from an ongoing study to quantify the presence of metaldehyde in surface waters within a UK catchment used for drinking water abstraction. High resolution water quality data from auto-samplers installed in rivers are coupled with radar rainfall, catchment characteristics and land use data to i) understand which hydro-meteorological characteristics of the catchment trigger the peak migration of metaldehyde to surface waters; ii) assess the relationship between measured metaldehyde levels and catchment characteristics such as land use, topographic index, proximity to water bodies and runoff generation area; iii) describe the current risks to drinking water supply and discuss mitigation options based on modelling and real-time control of water abstraction. Identifying the correlation between catchment attributes and metaldehyde generation will help in the development of effective catchment management strategies, which can help to significantly reduce the amount of metaldehyde finding its way into river water. Furthermore, the effectiveness of current water quality monitoring strategy in accurately quantifying the generation of metaldehyde from the catchment and its ability to benefit the development of effective catchment management practices has also been investigated.
Jones, K; Betaieb, M; Telford, D R
1990-11-01
The incidence of campylobacter enteritis in Lancaster City Health Authority is three times the UK average for similar sizes of population and has marked seasonal peaks in May and June. Environmental monitoring of surface waters around Lancaster showed that thermophilic campylobacters were absent from drinking water from the fells and from the clean upper reaches of the River Conder but were present in the main rivers entering Morecambe Bay, the lower reaches of the River Conder, the Lancaster canal, and seawater from the Lune estuary and Morecambe Bay. All the surface waters tested showed the same seasonality, namely, higher numbers in the winter months and low numbers or none in May, June and July. The absence of thermophilic campylobacters in the summer months may be due to high sunshine levels because experiments on the effects of light showed that campylobacters in sewage effluent and seawater were eliminated within 60 and 30 min of daylight respectively but survived for 24 h in darkness. As the concentrations of campylobacters in surface waters were at their lowest precisely at the time of peak infections in the community it is unlikely that surface waters form Lancaster's reservoir of campylobacter infection for the community.
REAL-TIME high-resolution urban surface water flood mapping to support flood emergency management
NASA Astrophysics Data System (ADS)
Guan, M.; Yu, D.; Wilby, R.
2016-12-01
Strong evidence has shown that urban flood risks will substantially increase because of urbanisation, economic growth, and more frequent weather extremes. To effectively manage these risks require not only traditional grey engineering solutions, but also a green management solution. Surface water flood risk maps based on return period are useful for planning purposes, but are limited for application in flood emergencies, because of the spatiotemporal heterogeneity of rainfall and complex urban topography. Therefore, a REAL-TIME urban surface water mapping system is highly beneficial to increasing urban resilience to surface water flooding. This study integrated numerical weather forecast and high-resolution urban surface water modelling into a real-time multi-level surface water mapping system for Leicester City in the UK. For rainfall forecast, the 1km composite rain radar from the Met Office was used, and we used the advanced rainfall-runoff model - FloodMap to predict urban surface water at both city-level (10m-20m) and street-level (2m-5m). The system is capable of projecting 3-hour urban surface water flood, driven by rainfall derived from UK Met Office radar. Moreover, this system includes real-time accessibility mapping to assist the decision-making of emergency responders. This will allow accessibility (e.g. time to travel) from individual emergency service stations (e.g. Fire & Rescue; Ambulance) to vulnerable places to be evaluated. The mapping results will support contingency planning by emergency responders ahead of potential flood events.
NASA Astrophysics Data System (ADS)
Le Vine, N.; Butler, A.; McIntyre, N.; Jackson, C.
2015-08-01
Land Surface Models (LSMs) are prospective starting points to develop a global hyper-resolution model of the terrestrial water, energy and biogeochemical cycles. However, there are some fundamental limitations of LSMs related to how meaningfully hydrological fluxes and stores are represented. A diagnostic approach to model evaluation is taken here that exploits hydrological expert knowledge to detect LSM inadequacies through consideration of the major behavioural functions of a hydrological system: overall water balance, vertical water redistribution in the unsaturated zone, temporal water redistribution and spatial water redistribution over the catchment's groundwater and surface water systems. Three types of information are utilised to improve the model's hydrology: (a) observations, (b) information about expected response from regionalised data, and (c) information from an independent physics-based model. The study considers the JULES (Joint UK Land Environmental Simulator) LSM applied to a deep-groundwater chalk catchment in the UK. The diagnosed hydrological limitations and the proposed ways to address them are indicative of the challenges faced while transitioning to a global high resolution model of the water cycle.
NASA Astrophysics Data System (ADS)
Le Vine, N.; Butler, A.; McIntyre, N.; Jackson, C.
2016-01-01
Land surface models (LSMs) are prospective starting points to develop a global hyper-resolution model of the terrestrial water, energy, and biogeochemical cycles. However, there are some fundamental limitations of LSMs related to how meaningfully hydrological fluxes and stores are represented. A diagnostic approach to model evaluation and improvement is taken here that exploits hydrological expert knowledge to detect LSM inadequacies through consideration of the major behavioural functions of a hydrological system: overall water balance, vertical water redistribution in the unsaturated zone, temporal water redistribution, and spatial water redistribution over the catchment's groundwater and surface-water systems. Three types of information are utilized to improve the model's hydrology: (a) observations, (b) information about expected response from regionalized data, and (c) information from an independent physics-based model. The study considers the JULES (Joint UK Land Environmental Simulator) LSM applied to a deep-groundwater chalk catchment in the UK. The diagnosed hydrological limitations and the proposed ways to address them are indicative of the challenges faced while transitioning to a global high resolution model of the water cycle.
Silicon concentrations in UK surface waters
NASA Astrophysics Data System (ADS)
Neal, Colin; Neal, Margaret; Reynolds, Brian; Maberly, Stephen C.; May, Linda; Ferrier, Robert C.; Smith, Jennifer; Parker, Julie E.
2005-03-01
This paper describes the variations in silicon concentrations in UK waters for a wide range of catchment systems (near pristine, rural, and agricultural and urban impacted systems). The paper largely concerns silicon levels in streams, rivers and lakes based on extensive data collected as part of several research and monitoring initiatives of national and international standing. For a detailed study of an upland catchment in mid-Wales, information on atmospheric inputs and groundwater chemistries is provided to supply background information to cross link to the surface water chemistry. Several hundred streams/rivers and lakes are dealt with within the study, dealing with the main types of freshwater riverine and lacustrine environments. The streams/rivers vary from small ephemeral runoff to the major rivers of the UK. The geographical location of sites vary from local sites in mid-Wales, to regional studies across Scotland, to the major eastern UK rivers entering the North Sea and to acid sensitive upland sites across Wales, the English Lake District, Scotland and Northern Ireland. The surface waters range in silicon concentration from 0 to 19 mg-Si l -1 (average for individual sites vary between 0.7 and 7.6 mg-Si l -1) and there are some clear variations which link to two primary processes (1) the relative inputs of groundwaters enriched in silicon and near surface waters more depleted in silicon and (2) plankton uptake of silicon during the summer months under baseflow conditions. Thermodynamic analysis reveals that the waters are approximately saturated with respect to either quartz or chalcedony except for two circumstances when undersaturation occurs. Firstly, undersaturation occurs at pH less than 5.5 in the upland areas and this is because the waters are mainly sourced from the acidic organic soils which are depleted in inorganic minerals. Secondly, undersaturation occurs in the lowland rivers when biological activity is at its highest and this leads to silicon removal from the water column. Quartz equilibrium can be approached (at pH>5.5) mainly within the upland systems which are not aquifer recharge dominated. However, for the lowland systems that are groundwater recharge dominated, it is chalcedony saturation which is approached, and such saturation is often observed within groundwaters. Similar patterns of undersaturation in response to biological uptake are seen in lakes and the extent of silicon depletion increases with biological productivity. Chalcedony oversaturation can occur for some UK rivers under baseflow conditions and this probably links to a higher rate of weathering.
Objective Assessment of Groundwater Resources for the Isle of Wight, UK
NASA Astrophysics Data System (ADS)
Simpson, M.; Butler, A. P.; McIntyre, N.
2012-12-01
Water resources are of crucial importance to the UK, and are essential to agriculture and industry as well as for domestic usage. A combination of factors - population growth, climate change and increasing regulatory restriction - will alter water availability over the next fifty years, potentially leading to shortages. Groundwater systems, representing 60% of available water in the southern UK, are typically conceptualised through geological interpretation, resulting in skilful and widely used systems models. Where these models are not successful, alternative approaches to groundwater resource assessments are required. A process for objectively modelling groundwater systems from borehole level observation data is presented, along with a methodology for incorporating climate change and population growth forecasts into an assessment of future water availability. The objective assessment described is a three stage process. Firstly, the observation data can be associated into groups, in order to best represent the water table response and thus identify units with consistent storage coefficient and transport process, analogous to varying aquifer media. Here this is achieved through the use of cluster analysis, applying various distance metrics to observation variances and incorporating spatial displacement. Secondly, the resulting groups are used to generate interpolated surfaces of mean water table level. A series of interpolative methods, including stochastic approaches, are applied and cross-validated to generate the most credible groundwater surface. Thirdly, the presence and influence of spatial and temporal anomalies such as groundwater abstraction points are identified through examination of observations furthest from the final interpolated groundwater surface. This groundwater systems model can then be incorporated into a groundwater/surface model relating rainfall to water table level and river flow, which in turn is used in conjunction with state-of-the-art climate projections and population change forecasts to generate projections of change for future scenarios. A case study illustrating the use of this methodology is presented. The Isle of Wight, a small island off the south coast of England with a population of 140,000, is exceptionally water stressed by UK standards and currently dependent on mainland transfers. These transfers are under review due to environmental pressure on the neighbouring county of Hampshire. Alongside this, a high population growth rate and the southerly location make the Isle of Wight the most likely part of the UK to be affected by reduced water availability. Lower Greensands and Chalk aquifer systems provide most of the island's non-imported water, yet these remain poorly understood. The principle reason for this is the exceptionally complex geology, a result of the island's location at the convergence of two asymmetric anticlinal structures and, in the case of the Lower Greensand group, multiple layers of alternating aquiferous and non-aquiferous material. A statistical assessment of borehole data may provide evidence for groundwater processes where direct lithological analysis is not appropriate. Through development of a credible groundwater systems model and sensible projections of future water availability, critical information can be provided to influence future water management policy.
Little, Christine; Sagoo, Satnam
2009-12-01
This study was undertaken to assess the cleanliness of food preparation areas, cleaning methods used, and the microbiological quality of water used by 1258 mobile food vendors in the UK. Samples collected included potable water (1102), cleaning cloths (801) and environmental swabs from food preparation surfaces (2704). Cleaning cloths were more heavily contaminated with Aerobic Colony Counts, Enterobacteriaceae, Escherichia coli, and Staphylococcus aureus compared to surfaces sampled. Surfaces that were visually dirty, wet, and chopping boards that were plastic or damaged also had high levels of these bacteria. Fifty-four percent of potable water samples were of poor microbiological quality; i.e. contained coliforms, E. coli and/or enterococci. A documented food safety management system was only evident in 40.1% of vendors and cleaning schedules were only used by 43.6%. Deficiencies in the correct use of cleaning materials, such as dilution factors and the minimum contact time for disinfectants, were identified.
Seasonal variations of alkenones and UK37 in the Chesapeake Bay water column
Mercer, J.L.; Zhao, M.; Colman, Steven M.
2005-01-01
Alkenone unsaturation indices (UK37 and U K???37) have long been used as proxies for surface water temperature in the open ocean. Recent studies have suggested that in other marine environments, variables other than temperature may affect both the production of alkenones and the values of the indices. Here, we present the results of a reconnaissance field study in which alkenones were extracted from particulate matter filtered from the water column in Chesapeake Bay during 2000 and 2001. A multivariate analysis shows a strong positive correlation between UK37 (and UK???37) values and temperature, and a significant negative correlation between UK37 (and UK???37) values and nitrate concentrations. However, temperature and nitrate concentrations also co-vary significantly. The temperature vs. UK37 relationships (UK37=0.018 (T)-0.162, R2=0.84, UK???37=0.013 (T)-0.04, R2=0.80) have lower slopes than the open-ocean equations of Prahl et al. [1988. Further evaluation of long-chain alkenones as indicators of paleoceanographic conditions. Geochimica et Cosmochimica Acta 52, 2303-2310] and Mu??ller et al. [1998. Calibration of the alkenone paleotemperature index UK???37 based on core-tops from the eastern South Atlantic and the global ocean (60??N-60??S). Geochimica et Cosmochimica Acta 62, 1757-1772], but are similar to the relationships found in controlled studies with elevated nutrient levels and higher nitrate:phosphate (N:P) ratios. This implies that high nutrient levels in Chesapeake Bay have either lowered the UK37 vs. temperature slope, or nutrient levels are the main controller of the U K37 index. In addition, particularly high abundances (>5% of total C37 alkenones) of the tetra-unsaturated ketone, C37:4, were found when water temperatures reached 25??C or higher, thus posing further questions about the controls on alkenone production as well as the biochemical roles of alkenones. ?? 2005 Elsevier Ltd. All rights reserved.
Prospects for Groundwater Drought Termination in the UK in 2017-18
NASA Astrophysics Data System (ADS)
Parry, S.; McKenzie, A.; Prudhomme, C.; Wilby, R.; Wood, P.
2017-12-01
The recovery of groundwater levels towards the end of a drought can lag behind surface water stores such as reservoirs or snowpack - as was the case for California in 2016/17. Groundwater replenishment is an important precursor to the ending of water restrictions, and an improved understanding of the range of plausible groundwater recovery scenarios would be useful for a range of stakeholders, including water managers, farmers and businesses. A method for characterising drought termination in hydrological data is applied systematically here to long time series of groundwater levels (some from the mid-1800s) for the UK. This analysis capitalises on the comprehensive perspective of post-drought recovery in the historical record to provide various outlooks of recovery in groundwater levels over seasonal to multi-year timeframes and to better understand how present conditions are likely to evolve. Rainfall deficiencies in the UK since summer 2016 limited replenishment during the 2016/17 winter recharge season. As a consequence, groundwater levels in south-east England were notably below normal in summer 2017. The possibility of an abrupt termination as occurred in 2012 can already be excluded, and extrapolating recent patterns suggests that very gradual recoveries may be underway. At many sites, normal conditions are not expected to return during 2017, and later still for sites in less responsive aquifers. This is supported by the multi-year drought durations typically found in the historical record, much more prolonged than those observed during the currently developing event. The rainfall rates that have driven historical drought termination events are also assessed for their likelihood across a range of timeframes and start months. Overall results underline the importance of the typical recharge season during the wetter winter half-year in averting multi-year groundwater drought events that would threaten water resources in the populous south-east of the UK. The approach adopted in this study could complement existing operational tools which provide outlooks for groundwater levels over seasonal to annual timescales, such as the UK Hydrological Outlook. The drought termination metrics are also applicable to surface water and hydrological contexts beyond the UK.
NASA Astrophysics Data System (ADS)
Castaneda, I. S.; Urann, B.; Phu, V.
2013-12-01
Two organic geochemical temperature proxies widely applied to marine sediments are the Uk'37 Index, based on long-chain alkenones produced by haptophyte algae, and TEX86, based on isoprenoid glycerol dialkyl glycerol tetraethers (GDGTs), produced by Thaumarchaeota. At some locations, temperature reconstructions based on Uk'37 and TEX86 are in agreement within the calibration errors of each proxy, while at other sites absolute Uk'37 and TEX86 reconstructed temperatures differ but both proxies reveal similar overall trends (e.g. Caley et al., 2011). In contrast, at other locations Uk'37 and TEX86 temperature reconstructions from the same samples yield dramatically different overall trends. Differences observed between Uk'37 and TEX86 temperature reconstructions have been attributed to a variety of factors including seasonal production biases, differences in preservation and lateral transport, and differences related to the depth habitat of the source organisms. An increasing number of studies have provided evidence that TEX86 likely reflects a subsurface water temperature in certain areas of the world's oceans and have used paired Uk'37 and TEX86 measurements to simultaneously examine sea surface and subsurface (in some cases thermocline) temperature variability (e.g. Lopes dos Santos et al., 2010; Rommerskirchen et al., 2011; Li et al., 2013). In the tropical N Atlantic, a distinctive signature of Atlantic Meridional Overturning Circulation (AMOC) slowdown is anticorrelated variation between surface and subsurface water temperatures (e.g. Chang et al., 2008; Zhang et al., 2007) where sea surface temperature (SST) cooling is accompanied by shallow subsurface warming (e.g. Chang et al., 2008). Lopes dos Santos et al. (2010) examined a site in the tropical NE Atlantic where they showed that in the modern Uk'37 reflects SST while TEXH86 likely reflects a thermocline temperature. The authors noted several periods during the past 200 kyr when surface cooling and subsurface warming occurred, which they attributed to AMOC slowdown. In this study, we examine sediments from ODP site 660 (NE Atlantic), located near the site studied by Lopes dos Santos et al. (2010), and use paired Uk'37-TEXH86 temperature measurements to investigate changes in sea surface and thermocline temperature variability over the past 4 Ma. We find that following Pliocene warmth, the Uk'37 record indicates an overall cooling trend since ~2.2 Ma, superimposed on glacial-interglacial temperature fluctuations. In contrast, the TEX86 record, which yields consistently cooler temperatures in comparison to Uk'37, does not exhibit an overall cooling trend during the Pleistocene nor elevated warmth during the Pliocene. In portions of the record, anticorrelated variability between Uk'37 and TEX86 temperatures is observed, likely reflecting differences in SST and thermocline temperatures related to AMOC variability. In addition, we examine the carbon (δ13C) and deuterium (δD) isotopic composition of plant leaf waxes, proxies for vegetation type (C3 vs. C4) and precipitation amount, respectively, as several studies have demonstrated close ties between AMOC variability and hydrological conditions in N Africa during the late Pleistocene and Holocene.
Uncertainty in surface water flood risk modelling
NASA Astrophysics Data System (ADS)
Butler, J. B.; Martin, D. N.; Roberts, E.; Domuah, R.
2009-04-01
Two thirds of the flooding that occurred in the UK during summer 2007 was as a result of surface water (otherwise known as ‘pluvial') rather than river or coastal flooding. In response, the Environment Agency and Interim Pitt Reviews have highlighted the need for surface water risk mapping and warning tools to identify, and prepare for, flooding induced by heavy rainfall events. This need is compounded by the likely increase in rainfall intensities due to climate change. The Association of British Insurers has called for the Environment Agency to commission nationwide flood risk maps showing the relative risk of flooding from all sources. At the wider European scale, the recently-published EC Directive on the assessment and management of flood risks will require Member States to evaluate, map and model flood risk from a variety of sources. As such, there is now a clear and immediate requirement for the development of techniques for assessing and managing surface water flood risk across large areas. This paper describes an approach for integrating rainfall, drainage network and high-resolution topographic data using Flowroute™, a high-resolution flood mapping and modelling platform, to produce deterministic surface water flood risk maps. Information is provided from UK case studies to enable assessment and validation of modelled results using historical flood information and insurance claims data. Flowroute was co-developed with flood scientists at Cambridge University specifically to simulate river dynamics and floodplain inundation in complex, congested urban areas in a highly computationally efficient manner. It utilises high-resolution topographic information to route flows around individual buildings so as to enable the prediction of flood depths, extents, durations and velocities. As such, the model forms an ideal platform for the development of surface water flood risk modelling and mapping capabilities. The 2-dimensional component of Flowroute employs uniform flow formulae (Manning's Equation) to direct flow over the model domain, sourcing water from the channel or sea so as to provide a detailed representation of river and coastal flood risk. The initial development step was to include spatially-distributed rainfall as a new source term within the model domain. This required optimisation to improve computational efficiency, given the ubiquity of ‘wet' cells early on in the simulation. Collaboration with UK water companies has provided detailed drainage information, and from this a simplified representation of the drainage system has been included in the model via the inclusion of sinks and sources of water from the drainage network. This approach has clear advantages relative to a fully coupled method both in terms of reduced input data requirements and computational overhead. Further, given the difficulties associated with obtaining drainage information over large areas, tests were conducted to evaluate uncertainties associated with excluding drainage information and the impact that this has upon flood model predictions. This information can be used, for example, to inform insurance underwriting strategies and loss estimation as well as for emergency response and planning purposes. The Flowroute surface-water flood risk platform enables efficient mapping of areas sensitive to flooding from high-intensity rainfall events due to topography and drainage infrastructure. As such, the technology has widespread potential for use as a risk mapping tool by the UK Environment Agency, European Member States, water authorities, local governments and the insurance industry. Keywords: Surface water flooding, Model Uncertainty, Insurance Underwriting, Flood inundation modelling, Risk mapping.
NASA Astrophysics Data System (ADS)
Rey Vicario, D.; Holman, I.
2016-12-01
The use of water for irrigation and on-farm reservoir filling is globally important for agricultural production. In humid climates, like the UK, supplemental irrigation can be critical to buffer the effects of rainfall variability and to achieve high quality crops. Given regulatory efforts to secure sufficient environmental river flows and meet rising water demands due to population growth and climate change, increasing water scarcity is likely to compound the drought challenges faced by irrigated agriculture in this region. Currently, water abstraction from surface waters for agricultural irrigation can be restricted by the Environment Agency during droughts under Section 57 of the Water Resources Act (1991), based on abnormally low river flow levels and rainfall forecast, causing significant economic impacts on irrigated agricultural production. The aim of this study is to assess the impact that climate change may have on agricultural abstraction in the UK within the context of the abstraction restriction triggers currently in place. These triggers have been applied to the `Future Flows hydrology' database to assess the likelihood of increasing restrictions on agricultural abstraction in the future by comparing the probability of voluntary and compulsory restrictions in the baseline (1961-1990) and future period (2071-2098) for 282 catchments throughout the whole of the UK. The results of this study show a general increase in the probability of future agricultural irrigation abstraction restrictions in the UK in the summer, particularly in the South West, although there is significant variability between the 11 ensemble members. The results also indicate that UK winters are likely to become wetter in the future, although in some catchments the probability of abstraction restriction in the reservoir refilling winter months (November-February) could increase slightly. An increasing frequency of drought events due to climate change is therefore likely to lead to more water abstraction restrictions, increasing the need for irrigators to adapt their businesses to increase drought resilience and hence food security.
Sequestration of arsenic in ombrotrophic peatlands
NASA Astrophysics Data System (ADS)
Rothwell, James; Hudson-Edwards, Karen; Taylor, Kevin; Polya, David; Evans, Martin; Allott, Tim
2014-05-01
Peatlands can be important stores of arsenic but we are lacking spectroscopic evidence of the sequestration pathways of this toxic metalloid in peatland environments. This study reports on the solid-phase speciation of anthropogenically-derived arsenic in atmospherically contaminated peat from the Peak District National Park (UK). Surface and sub-surface peat samples were analysed by synchrotron X-ray absorption spectroscopy on B18 beamline at Diamond Light Source (UK). The results suggest that there are contrasting arsenic sequestration mechanisms in the peat. The bulk arsenic speciation results, in combination with strong arsenic-iron correlations at the surface, suggest that iron (hydr)oxides are key phases for the immobilisation of arsenic at the peat surface. In contrast, the deeper peat samples are dominated by arsenic sulphides (arsenopyrite, realgar and orpiment). Given that these peats receive inputs solely from the atmosphere, the presence of these sulphide phases suggests an in-situ authigenic formation. Redox oscillations in the peat due to a fluctuating water table and an abundant store of legacy sulphur from historic acid rain inputs may favour the precipitation of arsenic sequestering sulphides in sub-surface horizons. Oxidation-induced loss of these arsenic sequestering sulphur species by water table drawdown has important implications for the mobility of arsenic and the quality of waters draining peatlands.
Description of trihalomethane levels in three UK water suppliers.
Whitaker, Heather; Nieuwenhuijsen, Mark J; Best, Nicola; Fawell, John; Gowers, Alison; Elliot, Paul
2003-01-01
Samples of drinking water are routinely analysed for four trihalomethanes (THMs), which are indicators of by-products of disinfection with chlorine, by UK water suppliers to demonstrate compliance with regulations. The THM data for 1992-1993 to 1997-1998 for three water suppliers in the north and midlands of England were made available for a UK epidemiological study of the association between disinfection by-products and adverse birth outcomes. This paper describes the THM levels in these three supply regions and discusses possible sources of variation. THM levels varied between different suppliers' water, and average THM levels were within the regulatory limits. Chloroform was the predominant THM in all water types apart from the ground water of one supplier. The supplier that distributed more ground and lowland surface water had higher dibromochloromethane (DBCM) and bromoform levels and lower chloroform levels than the other two suppliers. In the water of two suppliers, seasonal fluctuations in bromodichloromethane (BDCM) and DBCM levels were found with levels peaking in the summer and autumn. In the other water supplier, chloroform levels followed a similar seasonal trend whereas BDCM and DBCM levels did not. For all three water suppliers, chloroform levels declined throughout 1995 when there was a drought period. There was a moderate positive correlation between the THMs most similar in their structure (chloroform and BDCM, BDCM and DBCM, and DBCM and bromoform) and a slight negative correlation between chloroform and bromoform levels.
Manamsa, K; Lapworth, D J; Stuart, M E
2016-10-15
This paper explores the temporal variation of a broad suite of micro organic (MO) compounds within hydrologically linked compartments of a lowland Chalk catchment, the most important drinking water aquifer in the UK. It presents an assessment of results from relatively high frequency monitoring at a well-characterised site, including the type and concentrations of compounds detected and how they change under different hydrological conditions including exceptionally high groundwater levels and river flow conditions during 2014 and subsequent recovery. This study shows for the first time that within the Chalk groundwater there can be a greater diversity of the MOs compared to surface waters. Within the Chalk 26 different compounds were detected over the duration of the study compared to 17 in the surface water. Plasticisers (0.06-39μg/L) were found to dominate in the Chalk groundwater on 5 visits (38.4%) accounting for 14.5% of detections but contributing highest concentrations whilst other compounds dominated in the surface water. Trichloroethene and atrazine were among the most frequently detected compounds. The limit for the total pesticide concentration detected did not exceed EU/UK prescribed concentration values for drinking water. Emerging organic compounds such as caffeine, which currently do not have water quality limits, were also detected. The low numbers of compounds found within the hyporheic zone highlight the role of this transient interface in the attenuation and breakdown of the MOs, and provision of an important ecosystem service. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.
A conceptual model for the analysis of multi-stressors in linked groundwater-surface water systems.
Kaandorp, Vince P; Molina-Navarro, Eugenio; Andersen, Hans E; Bloomfield, John P; Kuijper, Martina J M; de Louw, Perry G B
2018-06-15
Groundwater and surface water are often closely coupled and are both under the influence of multiple stressors. Stressed groundwater systems may lead to a poor ecological status of surface waters but to date no conceptual framework to analyse linked multi-stressed groundwater - surface water systems has been developed. In this paper, a framework is proposed showing the effect of groundwater on surface waters in multiple stressed systems. This framework will be illustrated by applying it to four European catchments, the Odense, Denmark, the Regge and Dinkel, Netherlands, and the Thames, UK, and by assessing its utility in analysing the propagation or buffering of multi-stressors through groundwater to surface waters in these catchments. It is shown that groundwater affects surface water flow, nutrients and temperature, and can both propagate stressors towards surface waters and buffer the effect of stressors in space and time. The effect of groundwater on drivers and states depends on catchment characteristics, stressor combinations, scale and management practises. The proposed framework shows how groundwater in lowland catchments acts as a bridge between stressors and their effects within surface waters. It shows water managers how their management areas might be influenced by groundwater, and helps them to include this important, but often overlooked part of the water cycle in their basin management plans. The analysis of the study catchments also revealed a lack of data on the temperature of both groundwater and surface water, while it is an important parameter considering future climate warming. Copyright © 2018. Published by Elsevier B.V.
Assessing the applicability of organic SST proxies in an upwelling region (Arabian Sea)
NASA Astrophysics Data System (ADS)
Lattaud, J.; van Erk, M. R.; Reichart, G. J.; Schulz, H.; S Sinninghe Damsté, J.; Schouten, S.
2017-12-01
Multiple organic proxies have the potential to reconstruct sea surface temperature (SST), but their behaviour is not completely understood within upwelling areas. This holds in particular for the recently developed Long chain Diol Index1 (LDI), based on the ratio of 1,15-diols over 1,13-diols, both likely produced by Eustigmatophytes. We tested the applicability of the LDI by comparing it to the more established temperature proxies TEX86 and Uk¢37 in a sediment core (spanning the last 76 ky) from the northern Arabian Sea and in surface sediments (Pakistan margin). In the surface sediments, Uk¢37- and LDI-SSTs agree well with annual mean SST, but the TEX86-SST substantially overestimates SST. A better agreement is observed, when the 0-200 m TEX86 calibration is used, suggesting TEX86 reflects subsurface temperatures. The results from the sediment core reveal that the SST records differ in absolute reconstructed temperature and show different patterns. TEX86 subsurface temperatures show a continuous increase toward the Holocene and no stadial/interstadial differences, while the LDI-SST is constant around 26°C with the exception of some short-term cooling events during periods of intensified upwelling. The Uk¢37-SST varies between 22 and 26°C and follows the global δ18Obenthic foram curve and thus is representing mean annual SST in this region3. During stadials, the reduced monsoon and low upwelling intensity resulted in warming of the subsurface waters2, as indicated by higher TEX86 temperatures, while global cooling led to colder surface waters as reflected in lower Uk¢37-SSTs, thus reducing the thermal gradient in the water column2. During the interstadials, which are periods of strong upwelling3, there is a high proportion of 1,14-diols (>40%). This probably disturbs the LDI-SST signal because the diatoms that produce the 1,14-diols are also generating small amounts of the 1,13-diols4. This suggests that care has to be taken in applying the LDI in upwelling regions. References 1Rampen et al., 2012 2Tierney et al., 2015 3Emeis et al., 1995 4Rampen et al., 2007
Rivett, Michael O; Cuthbert, Mark O; Gamble, Richard; Connon, Lucy E; Pearson, Andrew; Shepley, Martin G; Davis, John
2016-09-15
Dynamic impact to the water environment of deicing salt application at a major highway (motorway) interchange in the UK is quantitatively evaluated for two recent severe UK winters. The contaminant transport pathway studied allowed controls on dynamic highway runoff and storm-sewer discharge to a receiving stream and its subsequent leakage to an underlying sandstone aquifer, including possible contribution to long-term chloride increases in supply wells, to be evaluated. Logged stream electrical-conductivity (EC) to estimate chloride concentrations, stream flow, climate and motorway salt application data were used to assess salt fate. Stream loading was responsive to salt applications and climate variability influencing salt release. Chloride (via EC) was predicted to exceed the stream Environmental Quality Standard (250mg/l) for 33% and 18% of the two winters. Maximum stream concentrations (3500mg/l, 15% sea water salinity) were ascribed to salt-induced melting and drainage of highway snowfall without dilution from, still frozen, catchment water. Salt persistance on the highway under dry-cold conditions was inferred from stream observations of delayed salt removal. Streambed and stream-loss data demonstrated chloride infiltration could occur to the underlying aquifer with mild and severe winter stream leakage estimated to account for 21 to 54% respectively of the 70t of increased chloride (over baseline) annually abstracted by supply wells. Deicing salt infiltration lateral to the highway alongside other urban/natural sources were inferred to contribute the shortfall. Challenges in quantifying chloride mass/fluxes (flow gauge accuracy at high flows, salt loading from other roads, weaker chloride-EC correlation at low concentrations), may be largely overcome by modest investment in enhanced data acquisition or minor approach modification. The increased understanding of deicing salt dynamic loading to the water environment obtained is relevant to improved groundwater resource management, highway salt application practice, surface-water - ecosystem management, and decision making on highway drainage to ground. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Pattison, Ian; Green, Daniel; Yu, Dapeng; Bosher, Lee; Wilby, Rob; Yang, Lili; Ryley, Tim
2016-04-01
Urban areas are increasingly susceptible to surface water flooding, with more intense precipitation and intensification of land development. Flooding has both direct impacts i.e. locations inundated with water, and indirect impacts i.e. transport networks, utility e.g. electricity/water services etc. The direct areas flooded evolve in space through the event, and are predicted by standard inundation models. However, the wider indirect impacts and the spatial-temporal patterns are less constrained and it is these that are needed to manage the impacts in real-time. This paper focusses on the Category One responders of the Fire and Rescue and Ambulance Services in the City of Leicester, East Midlands, UK. Leicester is ranked 16th out of 4215 settlements at risk of surface water flooding in the UK based upon the population at risk (15,200 people) (DEFRA, 2009). The analysis undertaken involved overlaying the flood extent with the Integrated Transport Network (ITN) data within a GIS framework. Then a simple transport routing algorithm was used to predict the travel time from specific nodes representing ambulance or fire stations to different parts of the city. Flood magnitudes with 1:20, 1:100 and 1:1000 return periods have been investigated. Under a scenario of no flooding, 100% of the city is accessible by the six fire stations in the city. However, in the 1 in 20 year surface water flood event the peak inundation results in 66.5% being accessible in the 10 minute permitted time and 6% is totally inaccessible. This falls to 40% and 13% respectively for the 1 in 100 year event. Maps show the area of the city that are accessible by two or more stations within the permitted response time, which shows these areas are the most resilient to surface water flooding. However, it isn't just the peak water depths at every location which impacts accessibility within the city but the spatial-temporal patterns of the inundation. The areas within the 10 minute response time expand and contract through the event as the inundated area makes roads in different parts of the city inaccessible through the event. These maps also allow key access roads to be identified. Key stakeholders, within the City of Leicester, have highlighted the potential benefit of such dynamic accessibility maps for their multi-agency planning and response for surface water flooding.
Prediction of River Flooding using Geospatial and Statistical Analysis in New York, USA and Kent, UK
NASA Astrophysics Data System (ADS)
Marsellos, A.; Tsakiri, K.; Smith, M.
2014-12-01
Flooding in the rivers normally occurs during periods of excessive precipitation (i.e. New York, USA; Kent, UK) or ice jams during the winter period (New York, USA). For the prediction and mapping of the river flooding, it is necessary to evaluate the spatial distribution of the water (volume) in the river as well as study the interaction between the climatic and hydrological variables. Two study areas have been analyzed; one in Mohawk River, New York and one in Kent, United Kingdom (UK). A high resolution Digital Elevation Model (DEM) of the Mohawk River, New York has been used for a GIS flooding simulation to determine the maximum elevation value of the water that cannot continue to be restricted in the trunk stream and as a result flooding in the river may be triggered. The Flooding Trigger Level (FTL) is determined by incremental volumetric and surface calculations from Triangulated Irregular Network (TIN) with the use of GIS software and LiDAR data. The prediction of flooding in the river can also be improved by the statistical analysis of the hydrological and climatic variables in Mohawk River and Kent, UK. A methodology of time series analysis has been applied for the decomposition of the hydrological (water flow and ground water data) and climatic data in both locations. The KZ (Kolmogorov-Zurbenko) filter is used for the decomposition of the time series into the long, seasonal, and short term components. The explanation of the long term component of the water flow using the climatic variables has been improved up to 90% for both locations. Similar analysis has been performed for the prediction of the seasonal and short term component. This methodology can be applied for flooding of the rivers in multiple sites.
An alternative approach to risk rank chemicals on the threat they pose to the aquatic environment.
Johnson, Andrew C; Donnachie, Rachel L; Sumpter, John P; Jürgens, Monika D; Moeckel, Claudia; Pereira, M Gloria
2017-12-01
This work presents a new and unbiased method of risk ranking chemicals based on the threat they pose to the aquatic environment. The study ranked 12 metals, 23 pesticides, 11 other persistent organic pollutants (POPs), 13 pharmaceuticals, 10 surfactants and similar compounds and 2 nanoparticles (total of 71) of concern against one another by comparing their median UK river water and median ecotoxicity effect concentrations. To complement this, by giving an assessment on potential wildlife impacts, risk ranking was also carried out by comparing the lowest 10th percentile of the effects data with the highest 90th percentile of the exposure data. In other words, risk was pared down to just toxicity versus exposure. Further modifications included incorporating bioconcentration factors, using only recent water measurements and excluding either lethal or sub-lethal effects. The top ten chemicals, based on the medians, which emerged as having the highest risk to organisms in UK surface waters using all the ecotoxicity data were copper, aluminium, zinc, ethinylestradiol (EE2), linear alkylbenzene sulfonate (LAS), triclosan, manganese, iron, methomyl and chlorpyrifos. By way of contrast, using current UK environmental quality standards as the comparator to median UK river water concentrations would have selected 6 different chemicals in the top ten. This approach revealed big differences in relative risk; for example, zinc presented a million times greater risk then metoprolol and LAS 550 times greater risk than nanosilver. With the exception of EE2, most pharmaceuticals were ranked as having a relatively low risk. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Comyn-Platt, Edward; Clark, Douglas; Blyth, Eleanor
2016-04-01
The UK is required to provide accurate estimates of the UK greenhouse gas (GHG; CO2, CH4 and N2O) emissions for the UNFCCC (United Nations Framework Convention on Climate Change). Process based land surface models (LSMs), such as the Joint UK Land Environment Simulator (JULES), attempt to provide such estimates based on environmental (e.g. land use and soil type) and meteorological conditions. The standard release of JULES focusses on the water and carbon cycles, however, it has long been suggested that a coupled carbon-nitrogen scheme could enhance simulations. This is of particular importance when estimating agricultural emission inventories where the carbon cycle is effectively managed via the human application of nitrogen based fertilizers. JULES-ECOSSE-FUN (JEF) links JULES with the Estimation of Carbon in Organic Soils - Sequestration and Emission (ECOSSE) model and the Fixation and Uptake of Nitrogen (FUN) model as a means of simulating C:N coupling. This work presents simulations from the standard release of JULES and the most recent incarnation of the JEF coupled system at the point and field scale. Various configurations of JULES and JEF were calibrated and fine-tuned based on comparisons with observations from three UK field campaigns (Crichton, Harwood Forest and Brattleby) specifically chosen to represent the managed vegetation types that cover the UK. The campaigns included flux tower and chamber measurements of CO2, CH4 and N2O amongst other meteorological parameters and records of land management such as application of fertilizer and harvest date at the agricultural sites. Based on the results of these comparisons, JULES and/or JEF will be used to provide simulations on the regional and national scales in order to provide improved estimates of the total UK emission inventory.
NASA Astrophysics Data System (ADS)
Lawrence, K. T.; Pearson, A.; Castañeda, I. S.; Peterson, L.
2017-12-01
Key features of late Neogene climate remain uncertain due to conflicting records derived from different sea surface temperature (SST) proxies. To resolve these disputes, it is necessary to explore both the consistencies and differences between paleotemperature estimates from critical oceanographic regimes. Here, we report orbital-scale climate variability at ODP Site 846 in the Eastern Equatorial Pacific (EEP) in the interval from 5-6 Ma using alkenone and TEX86 temperature estimates. Results from both proxies are very similar in their secular trends and magnitude of long-term temperature change; and spectral analysis demonstrates that the records are coherent and in-phase or nearly in-phase in both the obliquity and precession bands. However, we find that the temperatures reconstructed by TEX86 are consistently offset towards colder values by 2ºC with orbital-scale variations approximately twice the amplitude of the Uk'37 derived estimates. Both temperature records are antiphased - i.e. "colder" - at higher sediment alkenone concentrations, a qualitative indicator of increased glacial productivity. Temperature differences between the proxies are accentuated during glacial intervals in contrasts to modern observations of EEP surface and subsurface temperatures, which show that thermocline temperatures are fairly stable, and thus by analogy, glacial cooling and/or enhanced upwelling should have reduced rather than accentuated temperature gradients in the upper water column. Therefore, arguments that Uk'37 corresponds to temperature variability in the surface, while TEX86 responds to the subsurface, may be too simplistic. Instead, it appears generally true that high-productivity environments, including the EEP, tend to have negative TEX86 anomalies. This may reflect a dual dependence of TEX86 records on both water column temperature and local productivity. Overall, our data suggest that in the EEP and likely in other upwelling zones, paleotemperature data derived from these proxies should not necessarily be used interchangeably and only Uk'37 is suitable for determining absolute SSTs. However, our data also suggest that TEX86 may be suitable for estimating long-term trends in SST and for spectral and phase analysis in upwelling regimes.
NASA Astrophysics Data System (ADS)
Zink, Klaus-G.; Leythaeuser, Detlev; Melkonian, Michael; Schwark, Lorenz
2001-01-01
Distribution patterns of C 37 and C 38 polyunsaturated long-chain alkenones (LCAs) serve as proxies for the determination of paleotemperatures for marine surface waters. We studied Recent/Subrecent and Late Glacial/Holocene sediments from Germany, Austria, Russia, and the U.S. to test for a correspondence between LCA distribution and surface water temperature in limnic systems. Previously, reports of LCA occurrence were restricted to sediments of 6 wide distributed freshwater and alkaline lakes. In this study 13 of 27 investigated lakes contained LCAs in surface sediments with concentrations varying between 12 to 205 μg/g TOC. Late Glacial to Holocene sediment sequences from Lake Steisslingen and Lake Wummsee, (Germany), Lake Pichozero (Russia), and Brush Lake (U.S.A.) contained abundant LCAs with averaged concentrations of 33 to 7536 μg/g TOC. For the first time we observed the occurrence of LCAs within in the water column of oligotrophic Lake Stechlin (NE-Germany). Alkenones were restricted to the zone of maximum chlorophyll concentration within the water column indicating that LCAs have a biosynthetic origin and can be attributed to phototrophic (micro)algae. Attempts to identify the producing organism, however, were not successful. Culture experiments allow various phytoplankton to be excluded as producers. Alkenone-producing algae are evidently of small size, hindering microscopical identification. LCAs commonly occur in high concentrations in Late Glacial sediments, mainly during the cold period of the Younger Dryas, whereas the Holocene usually is devoid of polyunsaturated alkenones. The episodic occurrence of LCAs restricts their utility as proxies for continuous geological records. Furthermore, lack of microscopical verification and the episodic distribution allow for different producers of unsaturated alkenones in Recent and Late Glacial sediments. An empirical relationship between LCA distribution and temperature was observed. In fossil sediments from Lake Steisslingen, there is a good correspondence between Uk37 and the temperature-controlled δ 18O isotope ratio of lake chalk. Comparison of LCA patterns obtained from the uppermost centimetres of lake sediments with averaged summer surface water temperatures of the lakes studied, demonstrates a trend of covariance ( r2: Uk'37 = 0.90, Uk37 = 0.67; n = 9). Hence, the same mechanism that causes temperature-dependence of LCA patterns in marine systems might be effective in limnic settings. Identification of alkenone producers and their culture under controlled temperature are still mandatory before LCAs can be routinely applied as paleotemperature proxy in limnic systems.
NASA Astrophysics Data System (ADS)
Green, Daniel; Pattison, Ian; Yu, Dapeng
2016-04-01
Surface water (pluvial) flooding occurs when rainwater from intense precipitation events is unable to infiltrate into the subsurface or drain via natural or artificial drainage channels. Surface water flooding poses a serious hazard to urban areas across the world, with the UK's perceived risk appearing to have increased in recent years due to surface water flood events seeming more severe and frequent. Surface water flood risk currently accounts for 1/3 of all UK flood risk, with approximately two million people living in urban areas at risk of a 1 in 200-year flood event. Research often focuses upon using numerical modelling techniques to understand the extent, depth and severity of actual or hypothetical flood scenarios. Although much research has been conducted using numerical modelling, field data available for model calibration and validation is limited due to the complexities associated with data collection in surface water flood conditions. Ultimately, the data which numerical models are based upon is often erroneous and inconclusive. Physical models offer a novel, alternative and innovative environment to collect data within, creating a controlled, closed system where independent variables can be altered independently to investigate cause and effect relationships. A physical modelling environment provides a suitable platform to investigate rainfall-runoff processes occurring within an urban catchment. Despite this, physical modelling approaches are seldom used in surface water flooding research. Scaled laboratory experiments using a 9m2, two-tiered 1:100 physical model consisting of: (i) a low-cost rainfall simulator component able to simulate consistent, uniformly distributed (>75% CUC) rainfall events of varying intensity, and; (ii) a fully interchangeable, modular plot surface have been conducted to investigate and quantify the influence of a number of terrestrial and meteorological factors on overland flow and rainfall-runoff patterns within a modelled urban setting. Terrestrial factors investigated include altering the physical model's catchment slope (0°- 20°), as well as simulating a number of spatially-varied impermeability and building density/configuration scenarios. Additionally, the influence of different storm dynamics and intensities were investigated. Preliminary results demonstrate that rainfall-runoff responses in the physical modelling environment are highly sensitive to slight increases in catchment gradient and rainfall intensity and that more densely distributed building layouts significantly increase peak flows recorded at the physical model outflow when compared to sparsely distributed building layouts under comparable simulated rainfall conditions.
NASA Astrophysics Data System (ADS)
Wild, Simon; Befort, Daniel J.; Leckebusch, Gregor C.
2016-04-01
The British Isles experienced exceptional stormy and rainy weather conditions in winter 2013-2014 while large parts of central North America recorded near record minimum surface temperatures values. Potential drivers for these cold conditions include increasingly warm surface waters of the tropical west Pacific. It has been suggested these increasing sea surface temperatures could also be the cause for extreme weather over the Europe, particularly the UK. Testing this hypothesis, we investigate mechanisms linking the tropical west Pacific and European wind storm activity. We will firstly analyse anomaly patterns along such a potential link in winter 2013-14. Secondly, we will investigate whether these identified anomaly patterns show a strong interannual relationship in the recent past. Our results, using primarily ERA-Interim Reanalysis from 1979 to 2014, show an absolute maximum of wind storm frequency over the northeast Atlantic and the British Isles in winter 2013-14. We also find absolute minimum surface temperatures in central North America and increased convective activity over the tropical west Pacific in the same season. The winter 2013-14 was additionally characterized by anomalous warm sea surface temperatures over the subtropical northwest Atlantic. Although the interannual variability of wind storms in the northeast Atlantic and surface temperatures in North America are significantly anti-correlated, we cannot directly relate wind storm frequency with tropical west Pacific anomalies. We thus conclude that the conditions over the Pacific in winter 2013-14 were favourable but not sufficient to explain the record number of wind storms in this season. Instead, we suggest that warm north Atlantic sea surface temperature anomalies in combination with cold surface temperatures over North America played a more important role for generating higher wind storm counts over the northeast Atlantic and the UK.
NASA Astrophysics Data System (ADS)
Durand, Michael; Neal, Jeff; Rodriguez, Ernesto
2013-09-01
The Surface Water and Ocean Topography (SWOT) satellite is a swath-mapping radar interferometer that will provide water elevations over inland water bodies and over the ocean. Here we present a Bayesian algorithm that calculates a best estimate of river bathymetry, roughness coefficient, and discharge based on measurements of river height and slope. On the River Severn, UK, we use gage estimates of height and slope during an in-bank flow event to illustrate algorithm functionality. We validate our estimates of river bathymetry and discharge using in situ measurements. We first assumed that the lateral inflows from smaller tributaries were known. In this case, an accurate inverse to bathymetry and roughness was obtained giving a discharge RMSE of 10 %. We then allowed the lateral inflows to be unknown; accuracy in the bathymetry estimates dropped in this case, giving a discharge RMSE of 36 %. Finally, we explored the case where bathymetry in one reach was known; in this case, discharge RMSE was 15.6 %.
The UK Nitrate Time Bomb (Invited)
NASA Astrophysics Data System (ADS)
Ward, R.; Wang, L.; Stuart, M.; Bloomfield, J.; Gooddy, D.; Lewis, M.; McKenzie, A.
2013-12-01
The developed world has benefitted enormously from the intensification of agriculture and the increased availability and use of synthetic fertilizers during the last century. However there has also been unintended adverse impact on the natural environment (water and ecosystems) with nitrate the most significant cause of water pollution and ecosystem damage . Many countries have introduced controls on nitrate, e.g. the European Union's Water Framework and Nitrate Directives, but despite this are continuing to see a serious decline in water quality. The purpose of our research is to investigate and quantify the importance of the unsaturated (vadose) zone pathway and groundwater in contributing to the decline. Understanding nutrient behaviour in the sub-surface environment and, in particular, the time lag between action and improvement is critical to effective management and remediation of nutrient pollution. A readily-transferable process-based model has been used to predict temporal loading of nitrate at the water table across the UK. A time-varying nitrate input function has been developed based on nitrate usage since 1925. Depth to the water table has been calculated from groundwater levels based on regional-scale observations in-filled by interpolated river base levels and vertical unsaturated zone velocities estimated from hydrogeological properties and mapping. The model has been validated using the results of more than 300 unsaturated zone nitrate profiles. Results show that for about 60% of the Chalk - the principal aquifer in the UK - peak nitrate input has yet to reach the water table and concentrations will continue to rise over the next 60 years. The implications are hugely significant especially where environmental objectives must be achieved in much shorter timescales. Current environmental and regulatory management strategies rarely take lag times into account and as a result will be poorly informed, leading to inappropriate controls and conflicts between policy makers, environmentalists and industry.
Hydroecological impacts of climate change modelled for a lowland UK wetland
NASA Astrophysics Data System (ADS)
House, Andrew; Acreman, Mike; Sorensen, James; Thompson, Julian
2015-04-01
Conservation management of wetlands often rests on modifying hydrological functions to establish or maintain desired flora and fauna. Hence the ability to predict the impacts of climate change is highly beneficial. Here, the physically based, distributed model MIKE SHE was used to simulate hydrology for the Lambourn Observatory at Boxford, UK. This comprises a 10 ha lowland riparian wetland protected for conservation, where the degree of variability in the peat, gravel and chalk geology has clouded hydrological understanding. Notably, a weathered layer on the chalk aquifer surface seals it from overlying deposits, yet is highly spatially heterogeneous. Long-term monitoring yielded observations of groundwater and surface water levels for model calibration and validation. Simulated results were consistent with observed data and reproduced the effects of seasonal fluctuations and in-channel macrophyte growth. The adjacent river and subsidiary channel were found to act as head boundaries, exerting a general control on water levels across the site. Discrete areas of groundwater upwellings caused raised water levels at distinct locations within the wetland. These were concurrent to regions where the weathered chalk layer is absent. To assess impacts of climate change, outputs from the UK Climate Projections 2009 ensemble of global climate models for the 2080s are used to obtain monthly percentage changes in climate variables. Changes in groundwater levels were taken from a regional model of the Chalk aquifer. Values of precipitation and evapotranspiration were seen to increase, whilst groundwater levels decreased, resulting in the greater dominance of precipitation. The discrete areas of groundwater upwelling were seen to diminish or disappear. Simulated water levels were linked to specific requirements of wetland plants using water table depth zone diagrams. Increasing depth of winter and summer groundwater levels leads to a loss of Glyceria maxima and Phragmites australis, principal habitat for the endangered Vertigo moulinsiana. Further, the reduced influx of base-rich groundwater and increased dominance of high pH rain-fed waters alters the acidity of the soil. This leads to changes in species composition, with potential reductions in Carex paniculata, Caltha palustris and Typha latifolia.
Kasprzyk-Hordern, Barbara; Dinsdale, Richard M; Guwy, Alan J
2008-07-01
The presence and fate of 56 pharmaceuticals, personal care products, endocrine disruptors and illicit drugs (PPCPs) were investigated in the South Wales region of the UK. Two contrasting rivers: River Taff and River Ely were chosen for this investigation and were monitored for a period of 10 months. The impact of the factors affecting the levels of concentration of PPCPs and illicit drugs in surface water such as surrounding area, proximity to wastewater effluent and weather conditions, mainly rainfall was also investigated. Most PPCPs were frequently found in river water at concentrations reaching single microgL(-1) and their levels depended mainly on the extent of water dilution resulting from rainfall. Discharge of treated wastewater effluent into the river course was found to be the main cause of water contamination with PPCPs. The most frequently detected PPCPs represent the group of pharmaceuticals dispensed at the highest levels in the Welsh community. These were antibacterial drugs (trimethoprim, erythromycin-H(2)O and amoxicillin), anti-inflammatories/analgesics (paracetamol, tramadol, codeine, naproxen, ibuprofen and diclofenac) and antiepileptic drugs (carbamazepine and gabapentin). Only four PPCPs out of 56 (simvastatin, pravastatin, digoxin and digoxigenin) were not quantified over the course of the study. Several PPCPs were found to be both ubiquitous and persistent in the aqueous environment (e.g. erythromycin-H(2)O, codeine, carbamazepine, gabapentin and valsartan). The calculated average daily loads of PPCPs indicated that in total almost 6 kg of studied PPCPs are discharged daily into the studied rivers. The illicit drugs studied were found in rivers at low levels of ng L(-1). Average daily loads of amphetamine, cocaine and its main metabolite benzoylecgonine were as follows: 8, 1.2 and 39 gday(-1), respectively. Their frequent occurrence in surface water is primarily associated with their high illegal usage and is strongly associated with the discharge of insufficiently treated wastewater effluent.
The flux of radionuclides in flowback fluid from shale gas exploitation.
Almond, S; Clancy, S A; Davies, R J; Worrall, F
2014-11-01
This study considers the flux of radioactivity in flowback fluid from shale gas development in three areas: the Carboniferous, Bowland Shale, UK; the Silurian Shale, Poland; and the Carboniferous Barnett Shale, USA. The radioactive flux from these basins was estimated, given estimates of the number of wells developed or to be developed, the flowback volume per well and the concentration of K (potassium) and Ra (radium) in the flowback water. For comparative purposes, the range of concentration was itself considered within four scenarios for the concentration range of radioactive measured in each shale gas basin, the groundwater of the each shale gas basin, global groundwater and local surface water. The study found that (i) for the Barnett Shale and the Silurian Shale, Poland, the 1 % exceedance flux in flowback water was between seven and eight times that would be expected from local groundwater. However, for the Bowland Shale, UK, the 1 % exceedance flux (the flux that would only be expected to be exceeded 1 % of the time, i.e. a reasonable worst case scenario) in flowback water was 500 times that expected from local groundwater. (ii) In no scenario was the 1 % exceedance exposure greater than 1 mSv-the allowable annual exposure allowed for in the UK. (iii) The radioactive flux of per energy produced was lower for shale gas than for conventional oil and gas production, nuclear power production and electricity generated through burning coal.
NASA Technical Reports Server (NTRS)
Lahoz, W. A.; O'Neill, A.; Carr, E. S.; Harwood, R. S.; Froidevaux, L.; Read, W. G.; Waters, J. W.; Kumer, J. B.; Mergenthaler, J. L.; Roche, A. E.
1994-01-01
The three-dimensional evolution of stratospheric water vapor distributions observed by the Microwave Limb Sounder (MLS) during the period October 1991 - July 1992 is documented. The transport features inferred from the MLS water vapor distributions are corroborated using other dynamical fields, namely, nitrous oxide from the Cryogenic Limb Array Etalon Spectrometer instrument, analyzed winds from the U.K. Meteorological Office (UKMO), UKMO-derived potential vorticity, and the diabatic heating field. By taking a vortex-centered view and an along-track view, the authors observe in great detail the vertical and horizontal structure of the northern winter stratosphere. It is demonstrated that the water vapor distributions show clear signatures of the effects of diabatic descent through isentropic surfaces and quasi-horizontal transport along isentropic surfaces, and that the large-scale winter flow is organized by the interaction between the westerly polar vortex and the Aleutian high.
Incorporation of UK Met Office's radiation scheme into CPTEC's global model
NASA Astrophysics Data System (ADS)
Chagas, Júlio C. S.; Barbosa, Henrique M. J.
2009-03-01
Current parameterization of radiation in the CPTEC's (Center for Weather Forecast and Climate Studies, Cachoeira Paulista, SP, Brazil) operational AGCM has its origins in the work of Harshvardhan et al. (1987) and uses the formulation of Ramaswamy and Freidenreich (1992) for the short-wave absorption by water vapor. The UK Met Office's radiation code (Edwards and Slingo, 1996) was incorporated into CPTEC's global model, initially for short-wave only, and some impacts of that were shown by Chagas and Barbosa (2006). Current paper presents some impacts of the complete incorporation (both short-wave and long-wave) of UK Met Office's scheme. Selected results from off-line comparisons with line-by-line benchmark calculations are shown. Impacts on the AGCM's climate are assessed by comparing output of climate runs of current and modified AGCM with products from GEWEX/SRB (Surface Radiation Budget) project.
NASA Astrophysics Data System (ADS)
Mackay, Jonathan; Abesser, Corinna; Hughes, Andrew; Jackson, Chris; Kingdon, Andrew; Mansour, Majdi; Pachocka, Magdalena; Wang, Lei; Williams, Ann
2013-04-01
The River Thames catchment is situated in the south-east of England. It covers approximately 16,000 km2 and is the most heavily populated river basin in the UK. It is also one of the driest and has experienced severe drought events in the recent past. With the onset of climate change and human exploitation of our environment, there are now serious concerns over the sustainability of water resources in this basin with 6 million m3 consumed every day for public water supply alone. Groundwater in the Thames basin is extremely important, providing 40% of water for public supply. The principal aquifer is the Chalk, a dual permeability limestone, which has been extensively studied to understand its hydraulic properties. The fractured Jurassic limestone in the upper catchment also forms an important aquifer, supporting baseflow downstream during periods of drought. These aquifers are unconnected other than through the River Thames and its tributaries, which provide two-thirds of London's drinking water. Therefore, to manage these water resources sustainably and to make robust projections into the future, surface and groundwater processes must be considered in combination. This necessitates the simulation of the feedbacks and complex interactions between different parts of the water cycle, and the development of integrated environmental models. The Open Modelling Interface (OpenMI) standard provides a method through which environmental models of varying complexity and structure can be linked, allowing them to run simultaneously and exchange data at each timestep. This architecture has allowed us to represent the surface and subsurface flow processes within the Thames basin at an appropriate level of complexity based on our understanding of particular hydrological processes and features. We have developed a hydrological model in OpenMI which integrates a process-driven, gridded finite difference groundwater model of the Chalk with a more simplistic, semi-distributed conceptual model of the Jurassic limestone. A distributed river routing model of the Thames has also been integrated to connect the surface and subsurface hydrological processes. This application demonstrates the potential benefits and issues associated with implementing this approach.
NASA Astrophysics Data System (ADS)
House, A. R.; Thompson, J. R.; Acreman, M. C.
2016-03-01
Projected changes in climate are likely to substantially impact wetland hydrological conditions that will in turn have implications for wetland ecology. Assessing ecohydrological impacts of climate change requires models that can accurately simulate water levels at the fine-scale resolution to which species and communities respond. Hydrological conditions within the Lambourn Observatory at Boxford, Berkshire, UK were simulated using the physically based, distributed model MIKE SHE, calibrated to contemporary surface and groundwater levels. The site is a 10 ha lowland riparian wetland where complex geological conditions and channel management exert strong influences on the hydrological regime. Projected changes in precipitation, potential evapotranspiration, channel discharge and groundwater level were derived from the UK Climate Projections 2009 ensemble of climate models for the 2080s under different scenarios. Hydrological impacts of climate change differ through the wetland over short distances depending on the degree of groundwater/surface-water interaction. Discrete areas of groundwater upwelling are associated with an exaggerated response of water levels to climate change compared to non-upwelling areas. These are coincident with regions where a weathered chalk layer, which otherwise separates two main aquifers, is absent. Simulated water levels were linked to requirements of the MG8 plant community and Desmoulin's whorl snail (Vertigo moulinsiana) for which the site is designated. Impacts on each are shown to differ spatially and in line with hydrological impacts. Differences in water level requirements for this vegetation community and single species highlight the need for separate management strategies in distinct areas of the wetland.
NASA Astrophysics Data System (ADS)
Whelan, Michael; Ramos, Andre; Guymer, Ian; Villa, Raffaella; Jefferson, Bruce
2016-04-01
Pesticides make important contributions to modern agriculture but losses from land to water can present problems for environmental management, particularly in catchments where surface waters are abstracted for drinking water. Where artificial field drains represent a dominant pathway for pesticide transfers, buffer zones provide little mitigation potential. Instead, "on-line" constructed wetlands have been proposed as a potential means of reducing pesticide fluxes in drainage ditches and headwater streams. Here, we evaluate the potential of small free-surface wetlands to reduce pesticide concentrations in surface waters using a combination of field monitoring and numerical modelling. Two small constructed wetland systems in a first order catchment in Cambridgeshire, UK, were monitored over the 2014-2015 winter season. Discharge was measured at several flow control structures and samples were collected every eight hours and analysed for metaldehyde, a commonly-used molluscicide. Metaldehyde is moderately mobile and, like many other compounds, it has been regularly detected at high concentrations in surface water samples in a number of drinking water supply catchments in the UK over the past few years. However, it is unusually difficult to remove via conventional drinking water treatment which makes it particularly problematical for water companies. Metaldehyde losses from the upstream catchment were significant with peak concentrations occurring in the first storm events in early autumn, soon after application. Concentrations and loads appeared to be unaffected by transit through the wetland over a range of flow conditions - probably due to short solute residence times (quantified via several tracing experiments employing rhodamine WT - a fluorescent dye). A dynamic model, based on fugacity concepts, was constructed to describe chemical fate in the wetland system. The model was used to evaluate mitigation potential and management options under field conditions and for a range of different pesticides under alternative flow and wetland dimension scenarios. In agreement with observations, model predictions for metaldehyde losses in the monitored system were negligible. The scenario analysis suggested that, even for pesticides with a relatively short aquatic half life, wetland systems would need to be much larger than those studied here in order to get any appreciable attenuation. Shallow systems have highest potential for promoting losses due to biodegradation, if we assume that most degrading organisms reside in fixed biofilms in the sediment. Sorption is not predicted to represent a significant net sink, except over short time scales in the first runoff event after application.
Sea Ice Detection Based on Differential Delay-Doppler Maps from UK TechDemoSat-1
Zhu, Yongchao; Yu, Kegen; Zou, Jingui; Wickert, Jens
2017-01-01
Global Navigation Satellite System (GNSS) signals can be exploited to remotely sense atmosphere and land and ocean surface to retrieve a range of geophysical parameters. This paper proposes two new methods, termed as power-summation of differential Delay-Doppler Maps (PS-D) and pixel-number of differential Delay-Doppler Maps (PN-D), to distinguish between sea ice and sea water using differential Delay-Doppler Maps (dDDMs). PS-D and PN-D make use of power-summation and pixel-number of dDDMs, respectively, to measure the degree of difference between two DDMs so as to determine the transition state (water-water, water-ice, ice-ice and ice-water) and hence ice and water are detected. Moreover, an adaptive incoherent averaging of DDMs is employed to improve the computational efficiency. A large number of DDMs recorded by UK TechDemoSat-1 (TDS-1) over the Arctic region are used to test the proposed sea ice detection methods. Through evaluating against ground-truth measurements from the Ocean Sea Ice SAF, the proposed PS-D and PN-D methods achieve a probability of detection of 99.72% and 99.69% respectively, while the probability of false detection is 0.28% and 0.31% respectively. PMID:28704948
Establishing effective sentinels - Setting the baseline for shale gas
NASA Astrophysics Data System (ADS)
Ward, C.; Worrall, F.
2017-12-01
The UK has a nascent shale gas industry and, unlike the US we have the opportunity to establish structures both physical and regulatory to reassure the public that any impact of a developing shale gas will be .properly licensed, regulated, monitored and, if necessary, mitigated. To assess and indeed demonstrate an impact of any activity, let alone those of shale gas exploitation, it is necessary to show, within a reasonable level of certainty, that the industry has changed a environmental state over and above that which was true without the activity present. The need for demonstrating impact not only means that a baseline needs to be established but that the baseline needs to be robustly established within a statistical and probabilistic framework so that certainty of impact can be demonstrated. A number of technologies have been proposed for monitoring the water quality impacts of shale gas developments, however, to be an effective and robust sentinel of change the parameter should have several properties: it should be a lead indicator and not a lag indicator of change; it should have a high contrast with the normal or background activity; it should show a high specificity for the activity of concern and not be associated with other activities; and it should readily deployed in time and space. By far the greatest difference between the waters arising from a shale gas well pad and surface waters is nothing more than salinity or its associated determinds. The salinity of flowback water and deep formation water can be many times greater than seawater let alone greater than the salinity of most UK surface waters. Therefore, we have built a probabilistic model of the salinity of English surface waters. We have developed a generalised linear model of the existing salinity data available for English surface waters. Generalised linear modelling means that we can use all the existing data, the approach is entirely data driven; it does not require parameterisation; and can include existing factorial and covariate information. The model was developed in a Bayesian hierarchical framework. The model creates a dynamic baseline against which it is possible to assess whether an observation is within that expected for that river under those temporal and hydroclimatic conditions. The model is tested for the Vale of Pickering gasfield.
NASA Astrophysics Data System (ADS)
Turner, Andrew; Bhat, Gs; Evans, Jonathan; Marsham, John; Martin, Gill; Parker, Douglas; Taylor, Chris; Bhattacharya, Bimal; Madan, Ranju; Mitra, Ashis; Mrudula, Gm; Muddu, Sekhar; Pattnaik, Sandeep; Rajagopal, En; Tripathi, Sachida
2015-04-01
The monsoon supplies the majority of water in South Asia, making understanding and predicting its rainfall vital for the growing population and economy. However, modelling and forecasting the monsoon from days to the season ahead is limited by large model errors that develop quickly, with significant inter-model differences pointing to errors in physical parametrizations such as convection, the boundary layer and land surface. These errors persist into climate projections and many of these errors persist even when increasing resolution. At the same time, a lack of detailed observations is preventing a more thorough understanding of monsoon circulation and its interaction with the land surface: a process governed by the boundary layer and convective cloud dynamics. The INCOMPASS project will support and develop modelling capability in Indo-UK monsoon research, including test development of a new Met Office Unified Model 100m-resolution domain over India. The first UK detachment of the FAAM research aircraft to India, in combination with an intensive ground-based observation campaign, will gather new observations of the surface, boundary layer structure and atmospheric profiles to go with detailed information on the timing of monsoon rainfall. Observations will be focused on transects in the northern plains of India (covering a range of surface types from irrigated to rain-fed agriculture, and wet to dry climatic zones) and across the Western Ghats and rain shadow in southern India (including transitions from land to ocean and across orography). A pilot observational campaign is planned for summer 2015, with the main field campaign to take place during spring/summer 2016. This project will advance our ability to forecast the monsoon, through a programme of measurements and modelling that aims to capture the key surface-atmosphere feedback processes in models. The observational analysis will allow a unique and unprecedented characterization of monsoon processes that will feed directly into model development at the UK Met Office and Indian NCMRWF, through model evaluation at a range of scales and leading to model improvement by working directly with parametrization developers. The project will institute a new long-term series of measurements of land surface fluxes, a particularly unconstrained observation for India, through eddy covariance flux towers. Combined with detailed land surface modelling using the Joint UK Land Environment Simulator (JULES) model, this will allow testing of land surface initialization in monsoon forecasts and improved land-atmosphere coupling.
Alkenone temperature and salinity: An evaluation of long chain C37 alkenone in Lake Qinghai, China
NASA Astrophysics Data System (ADS)
Liu, W.; Liu, Z.; Fu, M.; An, Z.
2007-12-01
In recently years, the alkenone unsaturation index (Uk'37=C37:.2/(C37:2+ C37:3)) has been used to reconstructed paleo-temperature for lacustrine sediments. However, few studies have addressed whether the relative abundance of the C37:4 alkenone to the total C37 production (C37:4 percent) can reflect surface salinity changes in lake systems. Here we present the distribution of C37 long chain alkenone of modern lake sediments in Qinghai Lake, Qing-Tibet Plateau, to evaluate significance of abundance change of long chain C37 alkenone as an indicator of lake paleo-enviromental evolution. A group of surface sediments from different locations in the lake have been analyzed in this study. The results of long chain C37 alkenone from 28 surface sediments analyses shown relative abundance of C37:4 alkenone to total C37 production (C37:4 percent) change from 14.5 to 48.6 percent and the abundance of C37:4 alkenone is increasing with decreasing salinity of lake water. For the salinity lake in land, we suggested the relative abundance of C37:4 alkenone in lake sediments may be a indicator of paleo-silinity; We have also found that Uk'37 values are weakly correlated with salinity and C37:4 percent changes, implying that potential minor contributions of temperature and salinity effects to C37:4 percent and Uk'37 respectively cannot be excluded in this study. However, since these contributions are weak, we suggest that the C37:4 percent proxy can be used to reconstruct paleo-salinity changes at a regional scale, especially in lake systems, while Uk'37 remains as a powerful tool for reconstructions of paleo-temperature changes in the lake systems.
Increased ambient air temperature alters the severity of soil water repellency
NASA Astrophysics Data System (ADS)
van Keulen, Geertje; Sinclair, Kat; Hallin, Ingrid; Doerr, Stefan; Urbanek, Emilia; Quinn, Gerry; Matthews, Peter; Dudley, Ed; Francis, Lewis; Gazze, S. Andrea; Whalley, Richard
2017-04-01
Soil repellency, the inability of soils to wet readily, has detrimental environmental impacts such as increased runoff, erosion and flooding, reduced biomass production, inefficient use of irrigation water and preferential leaching of pollutants. Its impacts may exacerbate (summer) flood risks associated with more extreme drought and precipitation events. In this study we have tested the hypothesis that transitions between hydrophobic and hydrophilic soil particle surface characteristics, in conjunction with soil structural properties, strongly influence the hydrological behaviour of UK soils under current and predicted UK climatic conditions. We have addressed the hypothesis by applying different ambient air temperatures under controlled conditions to simulate the effect of predicted UK climatic conditions on the wettability of soils prone to develop repellency at different severities. Three UK silt-loam soils under permanent vegetation were selected for controlled soil perturbation studies. The soils were chosen based on the severity of hydrophobicity that can be achieved in the field: severe to extreme (Cefn Bryn, Gower, Wales), intermediate to severe (National Botanical Garden, Wales), and subcritical (Park Grass, Rothamsted Research near London). The latter is already highly characterised so was also used as a control. Soils were fully saturated with water and then allowed to dry out gradually upon exposure to controlled laboratory conditions. Soils were allowed to adapt for a few hours to a new temperature prior to initiation of the controlled experiments. Soil wettability was determined at highly regular intervals by measuring water droplet penetration times. Samples were collected at four time points: fully wettable, just prior to and after the critical soil moisture concentrations (CSC), and upon reaching air dryness (to constant weight), for further (ultra)metaproteomic and nanomechanical studies to allow integration of bulk soil characterisations with functional expression and nanoscale studies to generate deep mechanistic understanding of the roles of microbes in soil ecosystems. Our controlled soil pertubation studies have shown that an increase in ambient temperature has consistently affected the severity of soil water repellency. Surprisingly, a higher ambient air temperature impacts soils that in the field develop subcritical and extreme repellency, differently under controlled laboratory conditions. We will discuss the impact of these results in relation to predicted UK climatic conditions. Soil metaproteomics will provide mechanistic insight at the molecular level whether differential microbial adaptation is correlated with the apparent different response to a higher ambient air temperature.
What caused the Extreme Storm Season over the North Atlantic and the UK in Winter 2013-14?
NASA Astrophysics Data System (ADS)
Leckebusch, G. C.; Wild, S.; Befort, D. J.
2015-12-01
In winter 2013-2014, the UK experienced exceptional stormy and rainy weather conditions. Concurrently, surface temperatures over large parts of central North America fell to near record minimum values. One potential driver for these cold conditions is discussed to be the increasingly warm surface waters of the tropical west Pacific. It has been suggested these increasing sea surface temperatures could also be the cause for extreme weather over the British Isles. Testing this hypothesis, we investigate mechanisms linking the tropical west Pacific and European wind storm activity. We focus on two research questions. Firstly: Was a chain of anomaly patterns with origin in the west Pacific present in the winter 2013-14? And secondly: Can centres of action along such a chain be identified with a strong interannual relationship in the recent past? Our results, using primarily ERA-Interim Reanalysis from 1979 to 2014, show an absolute maximum of wind storm frequency over the northeast Atlantic and the British Isles in winter 2013-14. We also find absolute minimum surface temperatures in central North America and increased convective activity over the tropical west Pacific in the same season. The winter 2013-14 was additionally characterized by anomalous warm sea surface temperatures over the subtropical northwest Atlantic. Although the interannual variability of wind storms in the northeast Atlantic and surface temperatures in North America are significantly anti-correlated, we cannot directly relate wind storm frequency with tropical west Pacific anomalies. We thus conclude that the conditions over the Pacific in winter 2013-14 were favourable but not sufficient to explain the record number of wind storms in this season. Instead, we suggest that warm north Atlantic sea surface temperature anomalies in combination with cold surface temperatures over North America played a more important role for generating higher wind storm counts over the northeast Atlantic and the UK.
The impact of synoptic weather on UK surface ozone and implications for premature mortality
NASA Astrophysics Data System (ADS)
Pope, R. J.; Butt, E. W.; Chipperfield, M. P.; Doherty, R. M.; Fenech, S.; Schmidt, A.; Arnold, S. R.; Savage, N. H.
2016-12-01
Air pollutants, such as ozone, have adverse impacts on human health and cause, for example, respiratory and cardiovascular problems. In the United Kingdom (UK), peak surface ozone concentrations typically occur in the spring and summer and are controlled by emission of precursor gases, tropospheric chemistry and local meteorology which can be influenced by large-scale synoptic weather regimes. In this study we composite surface and satellite observations of summer-time (April to September) ozone under different UK atmospheric circulation patterns, as defined by the Lamb weather types. Anticyclonic conditions and easterly flows are shown to significantly enhance ozone concentrations over the UK relative to summer-time average values. Anticyclonic stability and light winds aid the trapping of ozone and its precursor gases near the surface. Easterly flows (NE, E, SE) transport ozone and precursor gases from polluted regions in continental Europe (e.g. the Benelux region) to the UK. Cyclonic conditions and westerly flows, associated with unstable weather, transport ozone from the UK mainland, replacing it with clean maritime (North Atlantic) air masses. Increased cloud cover also likely decrease ozone production rates. We show that the UK Met Office regional air quality model successfully reproduces UK summer-time ozone concentrations and ozone enhancements under anticyclonic and south-easterly conditions for the summer of 2006. By using established ozone exposure-health burden metrics, anticyclonic and easterly condition enhanced surface ozone concentrations pose the greatest public health risk.
NASA Astrophysics Data System (ADS)
Walker Karega, I. I.; Juhl, A. R.; D'Andrea, W. J.
2016-02-01
Alkenone paleothermometry (via the UK37 and UK'37 indices) is widely used to reconstruct sea surface temperature and, more recently, lake water temperature. Genetic analyses indicate that there is a diversity of different alkenone-producing lacustrine haptophytes, and differences among UK37-temperature calibrations suggest that unique calibrations might be required to quantify past temperature variation from individual lakes. The only term needed to quantify UK37-inferred temperature relative to a reference period (e.g., modern temperature, or 20th Century mean temperature) is the slope of the calibration regression: UK37-temperature sensitivity (i.e., the change in UK37 per °C temperature change). Here, we present new data developed by culturing four different species of alkenone-producing haptophyte algae across a range of temperatures (6-30 °C) and light levels (20-200 µE). The simultaneous culture of four distinct species allows direct comparison of the absolute quantities of alkenones and alkenoates, as well as other lipids, produced by different species of haptophytes under identical environmental conditions. Our results indicate that algal growth rate, when controlled by light intensity, has no impact on UK37 values. As expected, we find that growth temperature controls both the degree of alkenone unsaturation and the relative production of alkenones vs. alkenoates in all four species. Importantly, comparison of the four UK37-temperature calibrations resulting from our experiments with preexisting calibrations supports the hypothesis that UK37-temperature sensitivity is controlled by phylogeny. Therefore, even in the absence of a site-specific calibration, this term can be used to quantify past temperature variation from lake sediments if the genetic identity of the lake's alkenone-producer is known.
NASA Astrophysics Data System (ADS)
Fewtrell, Timothy J.; Duncan, Alastair; Sampson, Christopher C.; Neal, Jeffrey C.; Bates, Paul D.
2011-01-01
This paper describes benchmark testing of a diffusive and an inertial formulation of the de St. Venant equations implemented within the LISFLOOD-FP hydraulic model using high resolution terrestrial LiDAR data. The models are applied to a hypothetical flooding scenario in a section of Alcester, UK which experienced significant surface water flooding in the June and July floods of 2007 in the UK. The sensitivity of water elevation and velocity simulations to model formulation and grid resolution are analyzed. The differences in depth and velocity estimates between the diffusive and inertial approximations are within 10% of the simulated value but inertial effects persist at the wetting front in steep catchments. Both models portray a similar scale dependency between 50 cm and 5 m resolution which reiterates previous findings that errors in coarse scale topographic data sets are significantly larger than differences between numerical approximations. In particular, these results confirm the need to distinctly represent the camber and curbs of roads in the numerical grid when simulating surface water flooding events. Furthermore, although water depth estimates at grid scales coarser than 1 m appear robust, velocity estimates at these scales seem to be inconsistent compared to the 50 cm benchmark. The inertial formulation is shown to reduce computational cost by up to three orders of magnitude at high resolutions thus making simulations at this scale viable in practice compared to diffusive models. For the first time, this paper highlights the utility of high resolution terrestrial LiDAR data to inform small-scale flood risk management studies.
Assessment of Land and Water Resource Implications of the UK 2050 Carbon Plan
NASA Astrophysics Data System (ADS)
Konadu, D. D.; Sobral Mourao, Z.; Skelton, S.; Lupton, R.
2015-12-01
The UK Carbon Plan presents four low-carbon energy system pathways that achieves 80% GHG emission targets by 2050, stipulated in the UK Climate Change Act (2008). However, some of the energy technologies prescribed under these pathways are land and water intensive; but would the increase demand for land and water under these pathways lead to increased competition and stress on agricultural land, and water resources in the UK? To answer the above question, this study uses an integrated modelling approach, ForeseerTM, which characterises the interdependencies and evaluates the land and water requirement for the pathways, based on scenarios of power plant location, and the energy crop yield projections. The outcome is compared with sustainable limits of resource appropriation to assess potential stresses and competition for water and land by other sectors of the economy. The results show the Carbon Plan pathways have low overall impacts on UK water resources, but agricultural land use and food production could be significantly impacted. The impact on agricultural land use is shown to be mainly driven by projections for transport decarbonisation via indigenously sourced biofuels. On the other hand, the impact on water resources is mainly associated with increased inland thermal electricity generation capacity, which would compete with other industrial and public water demands. The results highlight the need for a critical appraisal of UK's long term low-carbon energy system planning, in particular bioenergy sourcing strategy, and the siting of thermal power generation in order to avert potential resource stress and competition.
Scales and Patterns of Nitrate Transport and Transformation in the Hyporheic Zone of a Lowland River
NASA Astrophysics Data System (ADS)
Naden, E.; Krause, S.; Tecklenburg, C.; Munz, M.
2009-04-01
The Hyporheic Zone (HZ) represents the spatially and temporally variable part of the streambed that is affected by the mixture of groundwater and surface water and often characterised by strong redox gradients and high turnover rates of redox reactive substances. The HZ has often been understood as a complex bioreactor with a high potential to affect groundwater-surface water exchange as well control the chemical signature of waters along the hyporheic passage. Currently, 73% of groundwater and 28% of UK rivers sampled exhibit either high nitrate levels or rising trends (Defra, 2008) Because of the high metabolic rates that have often be observed, the HZ is by many expected to potentially ameliorate groundwater nitrate fluxes and thus to reduce nitrate pollution and benefit freshwater ecosystems. The objective of this pilot study was to set up a monitoring program on a typical lowland river within glacio-fluvial deposits and well connected to the shallow groundwater aquifer. This study aims to derive a conceptual model of hyporheic exchange and nutrient metabolism in an agriculturally used lowland system including the development of upscaling strategies that allow for the assessment of hyporheic uptake or contribution on a subcatchment scale. The research area covers a 250 metre stream reach of the River Tern (Shropshire, UK), a lowland groundwater dependent surface water body at risk of failing to achieve ‘good water' status under the WFD, primarily due to diffuse agricultural pollution. In two horizontal arrays 42 multi piezometers have been installed in the river bed offering sampling from between three and eight sampling points ranging from 5 cm to 200 cm depth. These allow the sampling of streambed porewater from more than 150 locations. Additionally, ten shallow groundwater boreholes (up to 3m depth) have been installed within the riparian floodplain. From June to September 2008 head measurements were taken at the streambed piezometers, riparian groundwater boreholes and the river in order to determine the groundwater flowfield and exchange with the surface water. At the same time interval streambed pore water and riparian groundwater were sampled from piezometers and boreholes alongside surface water samples from the river. The samples were analysed for dissolved oxygen and major anion concentrations. Initial results confirm indicate that the water sources mixing in the HZ are statistically distinctive. In contrast to the many observed head water streams the exchange between groundwater and surface water is not just determined by gradually changing hydraulic conductivities of the sediment material but strongly controlled by the spatial pattern of a discontinuous impermeable regional peat layer located in 50 cm depth on average. The peat layer is separating the fluxes within the streambed into two (partially connected) flow systems, with semi-confined conditions underneath and pattern of surface water mixing above the peat. Areas where the peat layer is disrupted are characterised by strong connection of both flow systems. Dependent on flow paths and residence times redox conditions and nitrate concentrations are showing substantial changes along the hyporheic flow path. The spatial very heterogeneous patterns of nitrate concentrations in the streambed were found controlled by complex flow processes at multiple scales covering small scale hyporheic exchange in pools, riffles and sand bars as well as large scale pattern of groundwater - surface water connectivity and riparian influences.
Towards a simple representation of chalk hydrology in land surface modelling
NASA Astrophysics Data System (ADS)
Rahman, Mostaquimur; Rosolem, Rafael
2017-01-01
Modelling and monitoring of hydrological processes in the unsaturated zone of chalk, a porous medium with fractures, is important to optimize water resource assessment and management practices in the United Kingdom (UK). However, incorporating the processes governing water movement through a chalk unsaturated zone in a numerical model is complicated mainly due to the fractured nature of chalk that creates high-velocity preferential flow paths in the subsurface. In general, flow through a chalk unsaturated zone is simulated using the dual-porosity concept, which often involves calibration of a relatively large number of model parameters, potentially undermining applications to large regions. In this study, a simplified parameterization, namely the Bulk Conductivity (BC) model, is proposed for simulating hydrology in a chalk unsaturated zone. This new parameterization introduces only two additional parameters (namely the macroporosity factor and the soil wetness threshold parameter for fracture flow activation) and uses the saturated hydraulic conductivity from the chalk matrix. The BC model is implemented in the Joint UK Land Environment Simulator (JULES) and applied to a study area encompassing the Kennet catchment in the southern UK. This parameterization is further calibrated at the point scale using soil moisture profile observations. The performance of the calibrated BC model in JULES is assessed and compared against the performance of both the default JULES parameterization and the uncalibrated version of the BC model implemented in JULES. Finally, the model performance at the catchment scale is evaluated against independent data sets (e.g. runoff and latent heat flux). The results demonstrate that the inclusion of the BC model in JULES improves simulated land surface mass and energy fluxes over the chalk-dominated Kennet catchment. Therefore, the simple approach described in this study may be used to incorporate the flow processes through a chalk unsaturated zone in large-scale land surface modelling applications.
Imported water risk: the case of the UK
NASA Astrophysics Data System (ADS)
Hoekstra, Arjen Y.; Mekonnen, Mesfin M.
2016-05-01
While the water dependency of water-scarce nations is well understood, this is not the case for countries in temperate and humid climates, even though various studies have shown that many of such countries strongly rely on the import of water-intensive commodities from elsewhere. In this study we introduce a method to evaluate the sustainability and efficiency of the external water footprint (WF) of a country, with the UK as an example. We trace, quantify and map the UK’s direct and indirect water needs and assess the ‘imported water risk’ by evaluating the sustainability of the water consumption in the source regions. In addition, we assess the efficiency of the water consumption in source areas in order to identify the room for water savings. We find that half of the UK’s global blue WF—the direct and indirect consumption of ground- and surface water resources behind all commodities consumed in the UK—is located in places where the blue WF exceeds the maximum sustainable blue WF. About 55% of the unsustainable part of the UK’s blue WF is located in six countries: Spain (14%), USA (11%), Pakistan (10%), India (7%), Iran (6%), and South Africa (6%). Our analysis further shows that about half of the global consumptive WF of the UK’s direct and indirect crop consumption is inefficient, which means that consumptive WFs exceed specified WF benchmark levels. About 37% of the inefficient part of the UK’s consumptive WF is located in six countries: Indonesia (7%), Ghana (7%), India (7%), Brazil (6%), Spain (5%), and Argentina (5%). In some source countries, like Pakistan, Iran, Spain, USA and Egypt, unsustainable and inefficient blue water consumption coincide. We find that, by lowering overall consumptive WFs to benchmark levels, the global blue WF of UK crop consumption could be reduced by 19%. We discuss four strategies to mitigate imported water risk: become more self-sufficient in food; diversify the import of water-intensive commodities, favouring the sourcing from water-abundant regions; reconsider the import of water-intensive commodities from the regions that are most severely water stressed altogether; and collaborate internationally with source countries with unsustainable water use where opportunities exist to increase water productivity.
Pullan, S P; Whelan, M J; Rettino, J; Filby, K; Eyre, S; Holman, I P
2016-09-01
This paper describes the development and application of IMPT (Integrated Model for Pesticide Transport), a parameter-efficient tool for predicting diffuse-source pesticide concentrations in surface waters used for drinking water supply. The model was applied to a small UK headwater catchment with high frequency (8h) pesticide monitoring data and to five larger catchments (479-1653km(2)) with sampling approximately every 14days. Model performance was good for predictions of both flow (Nash Sutcliffe Efficiency generally >0.59 and PBIAS <10%) and pesticide concentrations, although low sampling frequency in the larger catchments is likely to mask the true episodic nature of exposure. The computational efficiency of the model, along with the fact that most of its parameters can be derived from existing national soil property data mean that it can be used to rapidly predict pesticide exposure in multiple surface water resources to support operational and strategic risk assessments. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.
Abraham, Mwesigye R; Susan, Tumwebaze B
2017-02-01
The mining and processing of copper in Kilembe, Western Uganda, from 1956 to 1982 left over 15 Mt of cupriferous and cobaltiferous pyrite dumped within a mountain river valley, in addition to mine water which is pumped to the land surface. This study was conducted to assess the sources and concentrations of heavy metals and trace elements in Kilembe mine catchment water. Multi-element analysis of trace elements from point sources and sinks was conducted which included mine tailings, mine water, mine leachate, Nyamwamba River water, public water sources and domestic water samples using ICP-MS. The study found that mean concentrations (mg kg -1 ) of Co (112), Cu (3320), Ni (131), As (8.6) in mine tailings were significantly higher than world average crust and were being eroded and discharged into water bodies within the catchment. Underground mine water and leachate contained higher mean concentrations (μg L -1 ) of Cu (9470), Co (3430) and Ni (590) compared with background concentrations (μg L -1 ) in un contaminated water of 1.9, 0.21 and 0.67 for Cu, Co and Ni respectively. Over 25% of household water samples exceeded UK drinking water thresholds for Al of 200 μg L -1 , Co exceeded Winsconsin (USA drinking) water thresholds of 40 μg L -1 in 40% of samples while Fe in 42% of samples exceeded UK thresholds of 200 μg L -1 . The study however found that besides mining activities, natural processes of geological weathering also contributed to Al, Fe, and Mn water contamination in a number of public water sources. Copyright © 2016 Elsevier Ltd. All rights reserved.
A national-scale analysis of the impacts of drought on water quality in UK rivers
NASA Astrophysics Data System (ADS)
Coxon, G.; Howden, N. J. K.; Freer, J. E.; Whitehead, P. G.; Bussi, G.
2015-12-01
Impacts of droughts on water quality qre difficult to quanitify but are essential to manage ecosystems and maintain public water supply. During drought, river water quality is significantly changed by increased residence times, reduced dilution and enhanced biogeochemical processes. But, the impact severity varies between catchments and depends on multiple factors including the sensitivity of the river to drought conditions, anthropogenic influences in the catchment and different delivery patterns of key nutrient, contaminant and mineral sources. A key constraint is data availability for key water quality parameters such that impacts of drought periods on certain determinands can be identified. We use national-scale water quality monitoring data to investigate the impacts of drought periods on water quality in the United Kingdom (UK). The UK Water Quality Sampling Harmonised Monitoring Scheme (HMS) dataset consists of >200 UK sites with weekly to monthly sampling of many water quality variables over the past 40 years. This covers several major UK droughts in 1975-1976, 1983-1984,1989-1992, 1995 and 2003, which cover severity, spatial and temporal extent, and how this affects the temporal impact of the drought on water quality. Several key water quality parameters, including water temperature, nitrate, dissolved organic carbon, orthophosphate, chlorophyll and pesticides, are selected from the database. These were chosen based on their availability for many of the sites, high sampling resolution and importance to the drinking water function and ecological status of the river. The water quality time series were then analysed to investigate whether water quality during droughts deviated significantly from non-drought periods and examined how the results varied spatially, for different drought periods and for different water quality parameters. Our results show that there is no simple conclusion as to the effects of drought on water quality in UK rivers; impacts are diverse both in terms of timing, magnitude and duration. We consider several scenarios in which management interventions may alleviate water quality pressures, and discuss how the many interacting factors need to be better characterised to support detailed mechanistic models to improve our process understanding.
NASA Astrophysics Data System (ADS)
Evans, Martin; Allott, Tim; Worrall, Fred; Rowson, James; Maskill, Rachael
2014-05-01
Water table is arguably the dominant control on biogeochemical cycling in peatland systems. Local water tables are controlled by peat surface water balance and lateral transfer of water driven by slope can be a significant component of this balance. In particular, blanket peatlands typically have relatively high surface slope compared to other peatland types so that there is the potential for water table to be significantly contolled by topographic context. UK blanket peatlands are also significantly eroded so that there is the potential for additional topographic drainage of the peatland surface. This paper presents a topographically driven model of blanket peat water table. An initial model presented in Allott et al. (2009) has been refined and tested against further water table data collected across the Bleaklow and Kinderscout plateaux of the English Peak District. The water table model quantifies the impact of peat erosion on water table throughout this dramatically dissected landscape demonstrating that almost 50% of the landscape has suffered significant water table drawdown. The model calibrates the impact of slope and degree of dissection on local water tables but does not incorporate any effects of surface cover on water table conditions. Consequently significant outliers in the test data are potentially indicative of important impacts of surface cover on water table conditions. In the test data presented here sites associated with regular moorland burning are significant outliers. The data currently available do not allow us to draw conclusions around the impact of land cover but they indicate an important potential application of the validated model in controlling for topographic position in further testing of the impact of land cover on peatland water tables. Allott, T.E.H. & Evans, M.G., Lindsay, J.B., Agnew, C.T., Freer, J.E., Jones, A. & Parnell, M. Water tables in Peak District blanket peatlands. Moors for the Future Report No. 17. Moors for the Future Partnership, Edale, 47pp.
Weedon, Christopher Michael; Murphy, Clodagh; Sweaney, Geoff
2017-01-01
Owing to legislation change (which made General Binding Rules effective from 1 January 2015) unless discharge is to specified environmentally sensitive sites, small sewage discharges (SSDs) in England - that is, <2 m 3 d -1 to ground; <5 m 3 d -1 to surface waters - no longer require an Environmental Permit (EP) and need not be registered for exemption, provided discharge to surface waters is preceded by treatment using equipment complying with BS EN 12566. This effectively excludes the use of treatment wetlands, unless covered by an EP, because the cost of certification to EN 12566 for bespoke designs is prohibitive. EPs take up to four months to obtain. Therefore, the new legislation has created a commercial disadvantage for constructed wetlands treating SSDs, compared with mass-produced sewage treatment plants. However, the UK statutory pollution regulators have maintained a dialogue with the Constructed Wetland Association (CWA), with a view to assessing whether treatment of SSD using constructed wetlands might be allowable, without requiring EPs. This paper presents treatment performance data obtained over 15 years, from a variety of full-scale operational treatment wetlands, as supporting evidence for design guidelines, proposed by the CWA to the UK regulators, for the implementation of constructed wetlands continuously passively treating SSD to 20:30:20 mg l -1 BOD/SS/NH4-N under a wide range of loading rates. Relevant experience of UK designers, installers and operators since the early 1990s is included, resulting in recommended physical design criteria and loading rates for compact vertical flow reed beds, presented here as key elements of the draft guidelines.
Carbon and Nutrient Dynamics and Fluxes in the Northwest European Continental Shelf Sea
NASA Astrophysics Data System (ADS)
Humphreys, M. P.; Moore, M. M.; Achterberg, E. P.; Griffiths, A.; Smilenova, A.; Chowdhury, M. Z. H.; Kivimae, C.; Hartman, S. E.; Hopkins, J.; Woodward, M. S.
2016-02-01
Despite covering only about 5 % of the Earth's ocean surface area, shallow marginal seas support 15-20 % of global primary productivity, and are the key interface between the land and the open ocean. They are therefore of critical importance to marine biogeochemical cycles, and may have a significant role in ocean uptake and storage of anthropogenic carbon dioxide (CO2). However, their behaviour is significantly more complex than that of the open ocean, because of the greater heterogeneity of the underlying physical, chemical and biological processes acting upon them. Detailed case-studies of individual regions are therefore essential in order to accurately evaluate their net global influence. The Northwest European continental shelf, in particular the Celtic Sea, was the target of extensive hydrographic sampling from March 2014 to September 2015, as part of the UK Shelf Seas Biogeochemistry research programme (UK-SSB). Here, we use the UK-SSB carbonate chemistry and macronutrient measurements to describe the seasonal biogeochemical cycle in the Celtic Sea. The 100-200 m deep water column proceeds from vertically well mixed in winter to a strongly stratified two-layer structure over spring-summer. The associated seasonal cycle in near-surface biological activity removes dissolved inorganic carbon (DIC) and nutrients, some of which are then exported into the deeper layer. Calculating total inventories of the biogeochemical variables throughout the seasonal cycle, we determine seasonal net CO2 uptake and investigate whether non-Redfieldian macronutrient uptake and remineralisation processes occur. Combining these results with estimated water exchange across the shelf edge further allows us to quantify the strength of the `shelf pump' sink for atmospheric (and anthropogenic) CO2.
What is the prognosis of nitrogen losses from UK soils?
NASA Astrophysics Data System (ADS)
Burt, T. P.; Worrall, F.; Whelan, M.; Howden, N. J.
2009-12-01
The UK’s high population density, intensive agriculture and relative short, unimpeded rivers mean that the UK is a known “hotspot” of fluvial nitrogen flux. Furthermore, it is known that the fluvial flux of nitrogen from the UK is increasing. This study estimates the release of nitrate from the UK terrestrial biosphere to understand this rising fluvial flux and i to assess the in-stream losses of nitrate, thusgiving an assessment of the fluvial component of the total nitrogen budget of UK. The approach taken by the study is to use an export coefficient model coupled with a description of mineralisation and immobilisation of nitrogen within soil reserves. The study applies the modelling approach to the whole of the UK from 1925 to 2007 using long term records of: land use (including - agricultural, forestry and urban uses); livestock; human population and atmospheric deposition. The study shows that: i) The flux of nitrate from the UK soils varied from 420 to 1463 Ktonnes N/yr with two peaks in the period since 1925, one in 1944 and one in 1967, the first is caused by mineralisation of soil organic matter following large-scale land use change in the Second World War, and the second is a multifactorial response to land use change and intensification. ii) The current trend in the release from soils is downward whilst the current fluvial flux at the tidal limit is upwards. With the current trends fluvial flux at the tidal limit will be greater than release from the soils of the UK, i.e. there will be net gain across the fluvial network. This apparent gain can be explained by the breakthrough of high nitrate groundwater into surface waters.
Reducing urban diffuse pollution and surface water flooding using retrofit street trees
NASA Astrophysics Data System (ADS)
Rothwell, James; Stringer, Pete; Causer, Katherine; Ryan, Matt; Mangan, Steve; Appleton, Ian; Savage, Mike
2016-04-01
Nature-based solutions for the management of urban stormwater have been growing in popularity, but there is a lack of empirical performance data for field-scale installations, especially in a UK context. To address this deficiency, a novel retrofit street tree demonstration project was commissioned in the City of Salford, near Manchester (UK). Three fifteen year-old London Plane trees were planted within a large roadside tree trench on an urban residential street. The DeepRoot Silvia Cell modular suspended pavement system was used to maximise soil volume, avoid compaction and support large tree growth. Road runoff is directed to the tree trench via AKO Slot Kerbs. Water is then distributed evenly throughout the whole system via a perforated pipe. Excess water is conveyed out of the system via an underdrain, which is subsequently connected to the sewer network. The tree trench is lined with an impermeable membrane. Access chambers are positioned on the inflow and outflow of the tree trench to facilitate hydrological and water quality monitoring. Installation was completed in autumn 2015 and monitoring will be conducted over a three year period. This paper will provide an overview of the installation process and present initial results on the pollutant removal performance and hydrological functioning of the system.
Global Occurrence and Emission of Rotaviruses to Surface Waters
Kiulia, Nicholas M.; Hofstra, Nynke; Vermeulen, Lucie C.; Obara, Maureen A.; Medema, Gertjan; Rose, Joan B.
2015-01-01
Group A rotaviruses (RV) are the major cause of acute gastroenteritis in infants and young children globally. Waterborne transmission of RV and the presence of RV in water sources are of major public health importance. In this paper, we present the Global Waterborne Pathogen model for RV (GloWPa-Rota model) to estimate the global distribution of RV emissions to surface water. To our knowledge, this is the first model to do so. We review the literature to estimate three RV specific variables for the model: incidence, excretion rate and removal during wastewater treatment. We estimate total global RV emissions to be 2 × 1018 viral particles/grid/year, of which 87% is produced by the urban population. Hotspot regions with high RV emissions are urban areas in densely populated parts of the world, such as Bangladesh and Nigeria, while low emissions are found in rural areas in North Russia and the Australian desert. Even for industrialized regions with high population density and without tertiary treatment, such as the UK, substantial emissions are estimated. Modeling exercises like the one presented in this paper provide unique opportunities to further study these emissions to surface water, their sources and scenarios for improved management. PMID:25984911
Subsynoptic-scale features associated with extreme surface gusts in UK extratropical cyclone events
NASA Astrophysics Data System (ADS)
Earl, N.; Dorling, S.; Starks, M.; Finch, R.
2017-04-01
Numerous studies have addressed the mesoscale features within extratropical cyclones (ETCs) that are responsible for the most destructive winds, though few have utilized surface observation data, and most are based on case studies. By using a 39-station UK surface observation network, coupled with in-depth analysis of the causes of extreme gusts during the period 2008-2014, we show that larger-scale features (warm and cold conveyer belts) are most commonly associated with the top 1% of UK gusts but smaller-scale features generate the most extreme winds. The cold conveyor belt is far more destructive when joining the momentum of the ETC, rather than earlier in its trajectory, ahead of the approaching warm front. Sting jets and convective lines account for two thirds of severe surface gusts in the UK.
NASA Astrophysics Data System (ADS)
Wilebore, Beccy; Willis, Kathy
2016-04-01
Landcover conversion is one of the largest anthropogenic threats to ecological services globally; in the EU around 1500 ha of biodiverse land are lost every day to changes in infrastructure and urbanisation. This land conversion directly affects key ecosystem services that support natural infrastructure, including water flow regulation and the mitigation of flood risks. We assess the sensitivity of runoff production to landcover in the UK at a high spatial resolution, using a distributed hydrologic model in the regional land-surface model JULES (Joint UK Land Environment Simulator). This work, as part of the wider initiative 'NaturEtrade', will create a novel suite of easy-to-use tools and mechanisms to allow EU landowners to quickly map and assess the value of their land in providing key ecosystem services.
NASA Astrophysics Data System (ADS)
Turner, A. G.; Bhat, G. S.; Evans, J. G.; Madan, R.; Marsham, J. H.; Martin, G.; Mitra, A. K.; Mrudula, G.; Parker, D. J.; Pattnaik, S.; Rajagopal, E. N.; Taylor, C.; Tripathi, S. N.
2016-12-01
INCOMPASS will build on a field and aircraft measurement campaign from the 2016 monsoon onset to better understand and predict monsoon rainfall. The monsoon supplies the majority of water in South Asia, however modelling and forecasting the monsoon from days to the season ahead is limited by large model errors that develop quickly. Likely problems lie in physical parametrizations such as convection, the boundary layer and land surface. At the same time, lack of detailed observations prevents more thorough understanding of monsoon circulation and its interaction with the land surface; a process governed by boundary layer and convective cloud dynamics. From May to July 2016, INCOMPASS used a modified BAe-146 jet aircraft operated by the UK Facility for Airborne Atmospheric Measurements (FAAM), for the first project of this scale in India. The India and UK team flew around 100 hours of science sorties from bases in northern and southern India. Flights from Lucknow in the northern plains took measurements to the west and southeast to allow sampling of the complete contrast from dry desert air to the humid environment over the north Bay of Bengal. These routes were repeated in the pre-monsoon and monsoon phases, measuring contrasting surface and boundary layer structures. In addition, flights from the southern base in Bengaluru measured contrasts from the Arabian Sea, across the intense rains of the Western Ghats mountains, over the rain shadow in southeast India and over the southern Bay of Bengal. Flight planning was performed with the aid of forecasts from a new UK Met Office 4km limited area model. INCOMPASS also installed a network of surface flux towers, as well as operating a cloud-base ceilometer and performing intensive radiosonde launches from a supersite in Kanpur. This presentation will outline preliminary results from the field campaign including new observations of the surface, boundary layer structure and atmospheric profiles together with detailed information on the timing of monsoon rain. We also outline our future plans for nested modelling of specific case studies of the 2016 monsoon, at resolutions at of 4km, 2km and 1km with explicit convection, as well as test development of a new 100m model over India. Observations will also be combined with further work using the Joint UK Land Environment Simulator (JULES) model.
NASA Astrophysics Data System (ADS)
Cranston, Michael; Speight, Linda; Maxey, Richard; Tavendale, Amy; Buchanan, Peter
2015-04-01
One of the main challenges for the flood forecasting community remains the provision of reliable early warnings of surface (or pluvial) flooding. The Scottish Flood Forecasting Service has been developing approaches for forecasting the risk of surface water flooding including capitalising on the latest developments in quantitative precipitation forecasting from the Met Office. A probabilistic Heavy Rainfall Alert decision support tool helps operational forecasters assess the likelihood of surface water flooding against regional rainfall depth-duration estimates from MOGREPS-UK linked to historical short-duration flooding in Scotland. The surface water flood risk is communicated through the daily Flood Guidance Statement to emergency responders. A more recent development is an innovative risk-based hydrometeorological approach that links 24-hour ensemble rainfall forecasts through a hydrological model (Grid-to-Grid) to a library of impact assessments (Speight et al., 2015). The early warning tool - FEWS Glasgow - presents the risk of flooding to people, property and transport across a 1km grid over the city of Glasgow with a lead time of 24 hours. Communication of the risk was presented in a bespoke surface water flood forecast product designed based on emergency responder requirements and trialled during the 2014 Commonwealth Games in Glasgow. The development of new approaches to surface water flood forecasting are leading to improved methods of communicating the risk and better performance in early warning with a reduction in false alarm rates with summer flood guidance in 2014 (67%) compared to 2013 (81%) - although verification of instances of surface water flooding remains difficult. However the introduction of more demanding hydrometeorological capabilities with associated greater levels of uncertainty does lead to an increased demand on operational flood forecasting skills and resources. Speight, L., Cole, S.J., Moore, R.J., Pierce, C., Wright, B., Golding, B., Cranston, M., Tavendale, A., Ghimire, S., and Dhondia, J. (2015) Developing surface water flood forecasting capabilities in Scotland: an operational pilot for the 2014 Commonwealth Games in Glasgow. Journal of Flood Risk Management, In Press.
NASA Astrophysics Data System (ADS)
Kasper, Sebastian; Castañeda, Isla; Tjallingii, Rik; Brummer, Geert-Jan; Schneider, Ralph; Sininnghe-Damsté, Jaap S.; Schouten, Stefan; van der Meer, Marcel T. J.
2014-05-01
Indian Ocean surface circulation through the Mozambique Channel forms the upstream source for the Agulhas Current, which is the main mechanism for transporting warm and salty waters from the Indian Ocean into the Atlantic via the Agulhas Leakage (Lutjeharms 2006). However, the Agulhas Leakage was reduced substantially during glacial times due to the northward migration of the subtropical fronts and shifts in the wind fields, and resulted in accumulation of warm and saline waters in the Southwest Indian Ocean (Peeters et al., 2004). A better understanding of the interactions between sea surface temperatures (SST) and sea surface salinity (SSS) in the Agulhas source region are fundamental for reconstructing past changes in this surface warm water route of the global conveyor and ocean-continent climate linkage with respect to South Africa. Here we present a record of the stable hydrogen isotope composition of the combined di- and tri- unsaturated alkenones (Dalkenone) that might relate to past SSS variations. We compare the variations of the Dalkenone with UK'37 SST records from sediment core 64PE304-80 located in the Mozambique Channel off the Zambezi River mouth. To estimate the influence of freshwater input at this site the alkenone hydrogen isotope record was compared to BIT Index values and Ca/Ti ratios reflecting the input of soil organic matter and lithogenic material on the core site, respectively. During the last glacial maximum (LGM) and the onset of Heinrich event 1 (HE1) at ~18,000 years, Dalkenone and UK'37 are positively correlated. The Dalkenone is more enriched during HE1 corresponding with high BIT values, increased Ca/Ti ratios, and relatively cold SST values. After ~16 ka, Dalkenone values decrease when UK'37 SST increases throughout the early Holocene, suggesting an increase of the continental precipitation and runoff during periods of increased SST. This period can be related to postglacial warming of the tropical ocean or due to a latitudinal shift in the ITCZ over Africa (e.g. Schefuss et al., 2011). Alternatively, the change in the paleosalinity signal may result from the change in the position of the Zambezi River and transport of the river plume by coastal currents and relative to the core location as a result of eustatic sea level rise. For the late Holocene the Dalkenone record shows relatively stable conditions that are interrupted by an excursion to more positive values from approximately 5000 to 1600 years BP. This excursion could be explained by variations of freshwater input related to the Zambezi run off.
NASA Astrophysics Data System (ADS)
Green, Daniel; Yu, Dapeng; Pattison, Ian
2017-04-01
Surface water flooding occurs when intense precipitation events overwhelm the drainage capacity of an area and excess overland flow is unable to infiltrate into the ground or drain via natural or artificial drainage channels, such as river channels, manholes or SuDS. In the UK, over 3 million properties are at risk from surface water flooding alone, accounting for approximately one third of the UK's flood risk. The risk of surface water flooding is projected to increase due to several factors, including population increases, land-use alterations and future climatic changes in precipitation resulting in an increased magnitude and frequency of intense precipitation events. Numerical inundation modelling is a well-established method of investigating surface water flood risk, allowing the researcher to gain a detailed understanding of the depth, velocity, discharge and extent of actual or hypothetical flood scenarios over a wide range of spatial scales. However, numerical models require calibration of key hydrological and hydraulic parameters (e.g. infiltration, evapotranspiration, drainage rate, roughness) to ensure model outputs adequately represent the flood event being studied. Furthermore, validation data such as crowdsourced images or spatially-referenced flood depth collected during a flood event may provide a useful validation of inundation depth and extent for actual flood events. In this study, a simplified two-dimensional inertial based flood inundation model requiring minimal pre-processing of data (FloodMap-HydroInundation) was used to model a short-duration, intense rainfall event (27.8 mm in 15 minutes) that occurred over the Loughborough University campus on the 28th June 2012. High resolution (1m horizontal, +/- 15cm vertical) DEM data, rasterised Ordnance Survey topographic structures data and precipitation data recorded at the University weather station were used to conduct numerical modelling over the small (< 2km2), contained urban catchment. To validate model outputs and allow a reconstruction of spatially referenced flood depth and extent during the flood event, crowdsourced images were obtained from social media (Twitter) and from individuals present during the flood event via the University noticeboards, as well as using dGPS flood depth data collected at one of the worst affected areas. An investigation into the sensitivity of key model parameters suggests that the numerical model code is highly sensitivity to changes within the recommended range of roughness and infiltration values, as well as changes in DEM and building mesh resolutions, but less sensitive to changes in evapotranspiration and drainage capacity parameters. The study also demonstrates the potential of using crowdsourced images to validate urban surface water flood models and inform parameterisation when calibrating numerical inundation models.
Coupling Radar Rainfall to Hydrological Models for Water Abstraction Management
NASA Astrophysics Data System (ADS)
Asfaw, Alemayehu; Shucksmith, James; Smith, Andrea; MacDonald, Ken
2015-04-01
The impacts of climate change and growing water use are likely to put considerable pressure on water resources and the environment. In the UK, a reform to surface water abstraction policy has recently been proposed which aims to increase the efficiency of using available water resources whilst minimising impacts on the aquatic environment. Key aspects to this reform include the consideration of dynamic rather than static abstraction licensing as well as introducing water trading concepts. Dynamic licensing will permit varying levels of abstraction dependent on environmental conditions (i.e. river flow and quality). The practical implementation of an effective dynamic abstraction strategy requires suitable flow forecasting techniques to inform abstraction asset management. Potentially the predicted availability of water resources within a catchment can be coupled to predicted demand and current storage to inform a cost effective water resource management strategy which minimises environmental impacts. The aim of this work is to use a historical analysis of UK case study catchment to compare potential water resource availability using modelled dynamic abstraction scenario informed by a flow forecasting model, against observed abstraction under a conventional abstraction regime. The work also demonstrates the impacts of modelling uncertainties on the accuracy of predicted water availability over range of forecast lead times. The study utilised a conceptual rainfall-runoff model PDM - Probability-Distributed Model developed by Centre for Ecology & Hydrology - set up in the Dove River catchment (UK) using 1km2 resolution radar rainfall as inputs and 15 min resolution gauged flow data for calibration and validation. Data assimilation procedures are implemented to improve flow predictions using observed flow data. Uncertainties in the radar rainfall data used in the model are quantified using artificial statistical error model described by Gaussian distribution and propagated through the model to assess its influence on the forecasted flow uncertainty. Furthermore, the effects of uncertainties at different forecast lead times on potential abstraction strategies are assessed. The results show that over a 10 year period, an average of approximately 70 ML/d of potential water is missed in the study catchment under a convention abstraction regime. This indicates a considerable potential for the use of flow forecasting models to effectively implement advanced abstraction management and more efficiently utilize available water resources in the study catchment.
NASA Astrophysics Data System (ADS)
Khamis, Kieran; Bradley, Chris; Hannah, David; Stevens, Rob
2014-05-01
Due to the recent development of field-deployable optical sensor technology, continuous quantification and characterization of surface water dissolved organic matter (DOM) is possible now. Tryptophan-like (T1) fluorescence has the potential to be a particularly useful indicator of human influence on water quality as T1 peaks are associated with the input of labial organic carbon (e.g. sewage or farm waste) and its microbial breakdown. Hence, real-time recording of T1 fluorescence could be particular useful for monitoring waste water infrastructure, treatment efficiency and the identification of contamination events at higher temporal resolution than available hitherto. However, an understanding of sensor measurement repeatability/transferability and interaction with environmental parameters (e.g. turbidity) is required. Here, to address this practical knowledge gap, we present results from a rigorous test of a commercially available submersible tryptophan fluorometer (λex 285, λem 350). Sensor performance was first examined in the laboratory by incrementally increasing turbidity under controlled conditions. Further to this the sensor was integrated into a multi-parameter sonde and field tests were undertaken involving: (i) a spatial sampling campaign across a range of surface water sites in the West Midlands, UK; and (ii) collection of high resolution (sub-hourly) samples from an urban stream (Bournbrook, Birmingham, U.K). To determine the ability of the sensor to capture spatiotemporal dynamics of urban waters DOM was characterized for each site or discrete time step using Excitation Emission Matrix spectroscopy and PARAFAC. In both field and laboratory settings fluorescence intensity was attenuated at high turbidity due to suspended particles increasing absorption and light scattering. For the spatial survey, instrument readings were compared to those obtained by a laboratory grade fluorometer (Varian Cary Eclipse) and a strong, linear relationship was apparent (R2 > 0.7). Parallel water sampling and laboratory analysis identified the potential for correction of T1 fluorescence intensity based on turbidity readings. These findings highlight the potential utility of real time monitoring of T1 fluorescence for a range of environmental applications (e.g. monitoring sewage treatment processes and tracing polluting DOM sources). However, if high/variable suspended sediment loads are anticipated concurrent monitoring of turbidity is required for accurate readings.
Ockenden, M C; Quinton, J N; Favaretto, N; Deasy, C; Surridge, B
2014-07-01
Surface water quality in the UK and much of Western Europe has improved in recent decades, in response to better point source controls and the regulation of fertilizer, manure and slurry use. However, diffuse sources of pollution, such as leaching or runoff of nutrients from agricultural fields, and micro-point sources including farmyards, manure heaps and septic tank sewerage systems, particularly systems without soil adsorption beds, are now hypothesised to contribute a significant proportion of the nutrients delivered to surface watercourses. Tackling such sources in an integrated manner is vital, if improvements in freshwater quality are to continue. In this research, we consider the combined effect of constructing small field wetlands and improving a septic tank system on stream water quality within an agricultural catchment in Cumbria, UK. Water quality in the ditch-wetland system was monitored by manual sampling at fortnightly intervals (April-October 2011 and February-October 2012), with the septic tank improvement taking place in February 2012. Reductions in nutrient concentrations were observed through the catchment, by up to 60% when considering total phosphorus (TP) entering and leaving a wetland with a long residence time. Average fluxes of TP, soluble reactive phosphorus (SRP) and ammonium-N (NH4-N) at the head of the ditch system in 2011 (before septic tank improvement) compared to 2012 (after septic tank improvement) were reduced by 28%, 9% and 37% respectively. However, TP concentration data continue to show a clear dilution with increasing flow, indicating that the system remained point source dominated even after the septic tank improvement.
Guelinckx, Isabelle; Tavoularis, Gabriel; König, Jürgen; Morin, Clémentine; Gharbi, Hakam; Gandy, Joan
2016-10-14
Little has been published on the contribution of food moisture (FM) to total water intake (TWI); therefore, the European Food Safety Authority assumed FM to contribute 20%-30% to TWI. The aim of the present analysis was to estimate and compare TWI, the percentage of water from FM and from fluids in population samples of France and UK. Data from 2 national nutrition surveys (Enquête Comportements et Consommations Alimentaires en France (CCAF) 2013 and the National Diet and Nutrition Survey (NDNS) 2008/2009-2011/2012) were analyzed for TWI and the contribution of water from FM and fluids. Children and adults TWI were significantly lower in France than in the UK. The contribution of water from foods was lower in the UK than in France (27% vs. 36%). As TWI increased, the proportion of water from fluids increased, suggesting that low drinkers did not compensate by increasing intake of water-rich foods. In addition, 80%-90% of the variance in TWI was explained by differences in water intake from fluids. More data on the contribution of FM to TWI is needed to develop more robust dietary recommendations on TWI and guidance on fluid intake for the general public.
Asset deterioration and discolouration in water distribution systems.
Husband, P S; Boxall, J B
2011-01-01
Water Distribution Systems function to supply treated water safe for human consumption and complying with increasingly stringent quality regulations. Considered primarily an aesthetic issue, discolouration is the largest cause of customer dissatisfaction associated with distribution system water quality. Pro-active measures to prevent discolouration are sought yet network processes remain insufficiently understood to fully justify and optimise capital or operational strategies to manage discolouration risk. Results are presented from a comprehensive fieldwork programme in UK water distribution networks that have determined asset deterioration with respect to discolouration. This is achieved by quantification of material accumulating as cohesive layers on pipe surfaces that when mobilised are acknowledged as the primary cause of discolouration. It is shown that these material layers develop ubiquitously with defined layer strength characteristics and at a consistent and repeatable rate dependant on water quality. For UK networks iron concentration in the bulk water is shown as a potential indicator of deterioration rate. With material layer development rates determined, management decisions that balance discolouration risk and expenditure to maintain water quality integrity can be justified. In particular the balance between capital investment such as improving water treatment output or pipe renewal and operational expenditure such as the frequency of network maintenance through flushing may be judged. While the rate of development is shown to be a function of water quality, the magnitude (peak or average turbidity) of discolouration incidents is shown to be dominated by hydraulic conditions. From this it can be proposed that network hydraulic management, such as regular periodic 'stressing', is a potential strategy in reducing discolouration risk. The ultimate application of this is the hydraulic design of self-cleaning networks to maintain discolouration risk below acceptable levels. Copyright © 2010 Elsevier Ltd. All rights reserved.
Cooke, Cindy M; Shaw, George; Collins, Chris D
2004-12-01
Isoproturon and trifluralin are herbicides of contrasting chemical characters and modes of action. Standard batch sorption procedures were carried out to investigate the individual sorption behaviour of 14C-isoproturon and 14C-trifluralin in five agricultural soils (1.8-4.2% OC), and the soil solid-liquid partition coefficients (Kd values) were determined. Trifluralin exhibited strong partitioning to the soil solid phase (Kd range 106-294) and low desorption potential, thus should not pose a threat to sensitive waters via leaching, although particle erosion and preferential flow pathways may facilitate transport. For isoproturon, soil adsorption was low (Kd range 1.96-5.75) and desorption was high, suggesting a high leaching potential, consistent with isoproturon being the most frequently found pesticide in UK surface waters. Soil partitioning was directly related to soil organic carbon (OC) content. Accumulation isotherms were modelled using a dual-phase adsorption model to estimate adsorption and desorption rate coefficients. Associations between herbicides and soil humic substances were also shown using gel filtration chromatography.
Jenkins, K; Surminski, S; Hall, J; Crick, F
2017-10-01
Climate change and increasing urbanization are projected to result in an increase in surface water flooding and consequential damages in the future. In this paper, we present insights from a novel Agent Based Model (ABM), applied to a London case study of surface water flood risk, designed to assess the interplay between different adaptation options; how risk reduction could be achieved by homeowners and government; and the role of flood insurance and the new flood insurance pool, Flood Re, in the context of climate change. The analysis highlights that while combined investment in property-level flood protection and sustainable urban drainage systems reduce surface water flood risk, the benefits can be outweighed by continued development in high risk areas and the effects of climate change. In our simulations, Flood Re is beneficial in its function to provide affordable insurance, even under climate change. However, the scheme does face increasing financial pressure due to rising surface water flood damages. If the intended transition to risk-based pricing is to take place then a determined and coordinated strategy will be needed to manage flood risk, which utilises insurance incentives, limits new development, and supports resilience measures. Our modelling approach and findings are highly relevant for the ongoing regulatory and political approval process for Flood Re as well as for wider discussions on the potential of insurance schemes to incentivise flood risk management and climate adaptation in the UK and internationally. Copyright © 2017 Elsevier B.V. All rights reserved.
2ND EF Conference in Turbulent Heat Transfer, Manchester, UK 1998. Volume 2
1998-06-01
cause maybe the fact that the rib size in this case is greater. As expected, the introduction of low-Re models leads to the prediction of higher ...Containment B. P. Axcell, C. Thianpong and J.E. Byrne Convective Heat Transfer to a Rotating Disk with Roughened Surfaces 6-3 6-9 T. V. Jones Theory ...total heat transfer. l INTRODUCTION For next generation water cooled reactors the use of passive safety features should be investigated in
Oberbeckmann, Sonja; Loeder, Martin G J; Gerdts, Gunnar; Osborn, A Mark
2014-11-01
Plastic pollution is now recognised as a major threat to marine environments and marine biota. Recent research highlights that diverse microbial species are found to colonise plastic surfaces (the plastisphere) within marine waters. Here, we investigate how the structure and diversity of marine plastisphere microbial community vary with respect to season, location and plastic substrate type. We performed a 6-week exposure experiment with polyethylene terephthalate (PET) bottles in the North Sea (UK) as well as sea surface sampling of plastic polymers in Northern European waters. Scanning electron microscopy revealed diverse plastisphere communities comprising prokaryotic and eukaryotic microorganisms. Denaturing gradient gel electrophoresis (DGGE) and sequencing analysis revealed that plastisphere microbial communities on PET fragments varied both with season and location and comprised of bacteria belonging to Bacteroidetes, Proteobacteria, Cyanobacteria and members of the eukaryotes Bacillariophyceae and Phaeophyceae. Polymers sampled from the sea surface mainly comprised polyethylene, polystyrene and polypropylene particles. Variation within plastisphere communities on different polymer types was observed, but communities were primarily dominated by Cyanobacteria. This research reveals that the composition of plastisphere microbial communities in marine waters varies with season, geographical location and plastic substrate type. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Leathard, A.; Fowler, H. J.; Kilsby, C. G.
2009-04-01
Anthropogenically aggravated climate change associated with intensive expansion of the global economy has increased the demand for water whilst simultaneously altering natural variability in its distribution, straining water resources unsustainably and inequitably in many parts of the world, increasing drought risk, and encouraging decision-makers to reconsider the security of water supply. Indeed, in the absence of additional resource development, contemporary planning forecasts imply increased water stress across much of the United Kingdom. The regulatory authorities of the UK currently promote increased efficiency of water delivery and consumption combined with a portfolio of financial instruments as a means of reducing water stress, maintaining present levels of consumer service without significant further exploitation of the environment. Despite an increasingly sophisticated understanding of climate change and its effects, significant uncertainty remains in the quantification of its impacts on the water sector, and questions persist as to the effectiveness of such demand management measures compared to that of more traditional infrastructure improvements. Faced with possible futures provided for by detrimentally over-stressed resources, what opportunities remain for future strategic development in the UK? Is there a single national strategy that is both politically and socially acceptable? This ongoing study aims to evolve robust national adaptation strategies by quantifying the projected impacts of climate change across mainland UK using multi-model and perturbed-physics ensembles of projected future climate, encapsulating uncertainties in a scenario-driven integrated water resources model incorporating socio-economic elements.
Tatsi, Kristi; Turner, Andrew
2014-03-01
Thallium is a highly toxic heavy metal whose concentrations and distributions in the aquatic environment are poorly defined. In this study, concentrations of aqueous and total Tl have been measured in water samples from a variety of rivers and effluents (the latter related to historical metal mining) in the county of Cornwall, SW England. Aqueous concentrations ranged from about 13 ng L(-1) in a river whose catchment contained no metal mines to 2,640 ng L(-1) in water abstracted directly from an abandoned mine shaft. Concentrations of Tl in rivers were greatest in the vicinity of mine-related effluents, with a maximum value measured of about 770 ng L(-1). Thallium was not efficiently removed by the conventional, active treatment of mine water, and displayed little interaction with suspended particles. Its mobility in surface waters, coupled with concentrations that are close to a quality guideline of 800 ng L(-1), is cause for concern. Accordingly, we recommend that the metal is more closely monitored in this and other regions impacted by mining activities. Copyright © 2013 Elsevier B.V. All rights reserved.
Davidson, C M; Peters, N J; Britton, A; Brady, L; Gardiner, P H E; Lewis, B D
2004-01-01
Modern analytical techniques have been applied to investigate the nature of lead pipe corrosion products formed in pH adjusted, orthophosphate-treated, low alkalinity water, under supply conditions. Depth profiling and surface analysis have been carried out on pipe samples obtained from the water distribution system in Glasgow, Scotland, UK. X-ray diffraction spectrometry identified basic lead carbonate, lead oxide and lead phosphate as the principal components. Scanning electron microscopy/energy-dispersive x-ray spectrometry revealed the crystalline structure within the corrosion product and also showed spatial correlations existed between calcium, iron, lead, oxygen and phosphorus. Elemental profiling, conducted by means of secondary ion mass spectrometry (SIMS) and secondary neutrals mass spectrometry (SNMS) indicated that the corrosion product was not uniform with depth. However, no clear stratification was apparent. Indeed, counts obtained for carbonate, phosphate and oxide were well correlated within the depth range probed by SIMS. SNMS showed relationships existed between carbon, calcium, iron, and phosphorus within the bulk of the scale, as well as at the surface. SIMS imaging confirmed the relationship between calcium and lead and suggested there might also be an association between chloride and phosphorus.
Performance of the JULES land surface model for UK Biogenic VOC emissions
NASA Astrophysics Data System (ADS)
Hayman, Garry; Comyn-Platt, Edward; Vieno, Massimo; Langford, Ben
2017-04-01
Emissions of biogenic non-methane volatile organic compounds (NMVOCs) are important for air quality and tropospheric composition. Through their contribution to the production of tropospheric ozone and secondary organic aerosol (SOA), biogenic VOCs indirectly contribute to climate forcing and climate feedbacks [1]. Biogenic VOCs encompass a wide range of compounds and are produced by plants for growth, development, reproduction, defence and communication [2]. There are both biological and physico-chemical controls on emissions [3]. Only a few of the many biogenic VOCs are of wider interest and only two or three (isoprene and the monoterpenes, α- and β-pinene) are represented in chemical transport models. We use the Joint UK Land Environment Simulator (JULES), the UK community land surface model, to estimate biogenic VOC emission fluxes. JULES is a process-based model that describes the water, energy and carbon balances and includes temperature, moisture and carbon stores [4, 5]. JULES currently provides emission fluxes of the 4 largest groups of biogenic VOCs: isoprene, terpenes, methanol and acetone. The JULES isoprene scheme uses gross primary productivity (GPP), leaf internal carbon and the leaf temperature as a proxy for the electron requirement for isoprene synthesis [6]. In this study, we compare JULES biogenic VOC emission estimates of isoprene and terepenes with (a) flux measurements made at selected sites in the UK and Europe and (b) gridded estimates for the UK from the EMEP/EMEP4UK atmospheric chemical transport model [7, 8], using site-specific or EMEP4UK driving meteorological data, respectively. We compare the UK-scale emission estimates with literature estimates. We generally find good agreement in the comparisons but the estimates are sensitive to the choice of the base or reference emission potentials. References (1) Unger, 2014: Geophys. Res. Lett., 41, 8563, doi:10.1002/2014GL061616; (2) Laothawornkitkul et al., 2009: New Phytol., 183, 27, doi:10.1111/j.1469-8137.2009.02859.x; (3) Grote and Niinemets, 2008: Plant Biol., 10, 8, doi:10.1055/s-2007-964975; (4) Best et al., 2011: Geosci. Model Dev., 4, 677, doi:10.5194/gmd-4-677-2011; (5) Clark et al., 2011: Geosci. Model Dev., 4, 701, doi:10.5194/gmd-4-701-2011; (6) Pacifico et al., 2011: Atmos. Chem. Phys., 11, 4371, doi:10.5194/acp-11-4371-2011; [7] Simpson et al., 2012: Atmos. Chem. Phys., 12, 7825, doi: 10.5194/acp-12-7825-2012; [8] Vieno et al., 2016: Atmos. Chem. Phys., 16, 265, doi: 10.5194/acp-16-265-2016.
Estimating Sources and Fluxes of Dissolved and Particulate Organic Matter in UK Rivers
NASA Astrophysics Data System (ADS)
Adams, Jessica; Tipping, Edward; Quinton, John; Old, Gareth
2014-05-01
Over the past two centuries, pools and fluxes of carbon, nitrogen and phosphorus in UK ecosystems have been altered by intensification of agriculture, land use change and atmospheric pollution leading to acidification and eutrophication of surface waters. In addition to this, climate change is now also predicted to substantially impact these systems. The CEH Long Term Large Scale (LTLS) project therefore aims to simulate the pools and fluxes of carbon, nitrogen and phosphorus and their stoichiometry during the cycling process. Through the N14C model, simulations of the release of C, N and P through drainage water and erosion processes will be predicted using historical climate data, which will be tested using contemporary data. For present data, water from four UK catchments (Ribble, Wiltshire Avon, Conwy, Dee) were collected at the tidal limit of each river, which included a combination of high and low flow samples predicted using 5 day forecasts and local weather station data. These samples were filtered, centrifuged and sent to the NERC radiocarbon facility for analysis by accelerator mass spectrometry (AMS) to obtain both PO14C and DO14C data. Radiocarbon enables a unique and dynamic way of estimating long term turnover rates of organic matter, and has proven to be an invaluable tool for measuring upland terrestrial and aquatic systems. It has however, been scarcely used in larger, lowland river systems. Since the riverine organic matter captured is likely to have originated from terrestrial and riparian sources, the radiocarbon data will be a rigorous test of the model's ability to simulate the coupling of erosion and leaching processes, and stoichiometric relationships between C:N:P.
NASA Astrophysics Data System (ADS)
de Wit, Heleen A.; Monteith, Don T.; Stoddard, John L.
2016-04-01
Concentrations of DOC in boreal surface waters have increased to levels that create challenges for water treatment plants, and that potentially impact lake habitat through increased anoxia and thermal mixing, and productivity. Aquatic transport of DOC from land to oceans is likely to increase, even if runoff patterns would remain stable. Reduced acid deposition appears to be a dominant driver behind the increase in DOC concentrations, through increasing organic matter solubility. We hypothesize that the higher solubility of organic matter makes DOC more susceptible to climate change. Here, we present trends in DOC from circa 500 lakes and streams in subarctic, boreal and temperate headwater catchments in Europe (UK, Fennoscandia, Czech Republic, Slovakia) and North America (Northeastern US, Ontario, Atlantic Canada) from 1990 until 2012; an extension of the trend analysis presented in Monteith et al. (2007). The water chemical data stem from national monitoring networks, assembled by the ICP Waters network. Sampling frequencies vary from 1 to 52 samples per year. Climate data were obtained from Climate Research Unit in the UK. Trends were calculated using the Mann-Kendall test and the Sen-slope estimator. We test 1) if DOC responds to changes in the rate of decline in acid deposition, and 2) if trends in temperature and precipitation affect trends and variability in DOC. Positive trends dominate: the median (±2.5% quartile) of the absolute and relative DOC trends is +0.06 (+0.36 to -0.02) mg C L-1 yr-1 and +1.4 (+4.7 to -0.9) % yr-1, respectively. Overall, the trends do not level off when comparing 1990-2004, and 1998-2012, except in the UK and Atlantic Canada. These two regions are strongly impacted by seasalt deposition but may also experience stronger warming than elsewhere. The response of DOC to changes in SO4 (expressed as trend ratios) is stronger in 1998-2012 than in 1990-2004. We will explore whether this changing relates to increasing dominance of drivers, such as temperature or precipitation, and will present multivariate models of DOC trends in relation to climate and deposition. References Monteith DT, Stoddard JL, Evans CD, de Wit HA, Forsius M, Hogasen T, Wilander A, Skjelkvale BL, Jeffries DS, Vuorenmaa J, Keller B, Kopacek J, Vesely J (2007) Dissolved organic carbon trends resulting from changes in atmospheric deposition chemistry. Nature 450(7169): 537-540
NASA Astrophysics Data System (ADS)
Leathard, A.; Fowler, H. J.; Kilsby, C. G.
2009-12-01
Anthropogenically aggravated climate change associated with intensive expansion of the global economy has increased the demand for water whilst simultaneously altering natural variability in its distribution, straining water resources unsustainably and inequitably in many parts of the world, increasing drought risk, and encouraging decision-makers to reconsider the security of water supply. Indeed, in the absence of additional resource development, contemporary planning forecasts imply increased water stress across much of the United Kingdom. Until recently the regulatory authorities of the UK promoted increased efficiency of water delivery and consumption combined with a portfolio of financial instruments as a means of reducing water stress, maintaining present levels of consumer service without significant further exploitation of the environment. However, despite an increasingly sophisticated understanding of climate change and its effects, significant uncertainty remains in the quantification of its impacts on the water sector, and questions persist as to the effectiveness of such demand management measures compared to that of more traditional infrastructure improvements. Faced with possible futures provided for by detrimentally over-stressed resources, what opportunities remain for future strategic development in the UK? Is there a single national strategy that is both politically and socially acceptable? Do the benefits of national water infrastructure projects outweigh their costs? This ongoing study aims to evolve robust national adaptation strategies by quantifying the projected impacts of climate change across mainland UK using multi-model and perturbed-physics ensembles of projected future climate, encapsulating uncertainties in a scenario-driven integrated water resources model incorporating socio-economic elements.
NASA Astrophysics Data System (ADS)
Turner, Andrew; Bhat, Ganapati; Evans, Jonathan; Madan, Ranju; Marsham, John; Martin, Gill; Mitra, Ashis; Mrudula, Gm; Parker, Douglas; Pattnaik, Sandeep; Rajagopal, En; Taylor, Christopher; Tripathi, Sachchida
2017-04-01
The INCOMPASS project uses data from a field and aircraft measurement campaign during the 2016 monsoon onset to better understand and predict monsoon rainfall. The monsoon supplies the majority of water in South Asia, however modelling and forecasting the monsoon from days to the season ahead is limited by large model errors that develop quickly. Likely problems lie in physical parametrizations such as convection, the boundary layer and land surface. At the same time, lack of detailed observations prevents more thorough understanding of monsoon circulation and its interaction with the land surface; a process governed by boundary layer and convective cloud dynamics. From May to July 2016, INCOMPASS used a modified BAe-146 jet aircraft operated by the UK Facility for Airborne Atmospheric Measurements (FAAM), for the first project of this scale in India. The India and UK team flew around 100 hours of science sorties from bases in northern and southern India. Flights from Lucknow in the northern plains took measurements to the west and southeast to allow sampling of the complete contrast from dry desert air to the humid environment over the north Bay of Bengal. These routes were repeated in the pre-monsoon and monsoon phases, measuring contrasting surface and boundary layer structures. In addition, flights from the southern base in Bengaluru measured contrasts from the Arabian Sea, across the intense rains of the Western Ghats mountains, over the rain shadow in southeast India and over the southern Bay of Bengal. Flight planning was performed with the aid of forecasts from a new UK Met Office 4km limited area model. INCOMPASS also installed a network of surface flux towers, as well as operating a cloud-base ceilometer and performing intensive radiosonde launches from a supersite in Kanpur. Here we will outline preliminary results from the field campaign including new observations of the surface, boundary layer structure and atmospheric profiles from aircraft data. We also include initial results from nested high-resolution modelling experiments of the 2016 monsoon, at a resolution of 4km in comparison with bespoke regional forecasts run throughout the field campaign.
Tang, R; Clark, J M; Bond, T; Graham, N; Hughes, D; Freeman, C
2013-02-01
Catchments draining peat soils provide the majority of drinking water in the UK. Over the past decades, concentrations of dissolved organic carbon (DOC) have increased in surface waters. Residual DOC can cause harmful carcinogenic disinfection by-products to form during water treatment processes. Increased frequency and severity of droughts combined with and increased temperatures expected as the climate changes, have potentials to change water quality. We used a novel approach to investigate links between climate change, DOC release and subsequent effects on drinking water treatment. We designed a climate manipulation experiment to simulate projected climate changes and monitored releases from peat soil and litter, then simulated coagulation used in water treatment. We showed that the 'drought' simulation was the dominant factor altering DOC release and affected the ability to remove DOC. Our results imply that future short-term drought events could have a greater impact than increased temperature on DOC treatability. Copyright © 2012 Elsevier Ltd. All rights reserved.
The UK particulate matter air pollution episode of March-April 2014: more than Saharan dust
NASA Astrophysics Data System (ADS)
Vieno, M.; Heal, M. R.; Twigg, M. M.; MacKenzie, I. A.; Braban, C. F.; Lingard, J. J. N.; Ritchie, S.; Beck, R. C.; Móring, A.; Ots, R.; Di Marco, C. F.; Nemitz, E.; Sutton, M. A.; Reis, S.
2016-04-01
A period of elevated surface concentrations of airborne particulate matter (PM) in the UK in spring 2014 was widely associated in the UK media with a Saharan dust plume. This might have led to over-emphasis on a natural phenomenon and consequently to a missed opportunity to inform the public and provide robust evidence for policy-makers about the observed characteristics and causes of this pollution event. In this work, the EMEP4UK regional atmospheric chemistry transport model (ACTM) was used in conjunction with speciated PM measurements to investigate the sources and long-range transport (including vertical) processes contributing to the chemical components of the elevated surface PM. It is shown that the elevated PM during this period was mainly driven by ammonium nitrate, much of which was derived from emissions outside the UK. In the early part of the episode, Saharan dust remained aloft above the UK; we show that a significant contribution of Saharan dust at surface level was restricted only to the latter part of the elevated PM period and to a relatively small geographic area in the southern part of the UK. The analyses presented in this paper illustrate the capability of advanced ACTMs, corroborated with chemically-speciated measurements, to identify the underlying causes of complex PM air pollution episodes. Specifically, the analyses highlight the substantial contribution of secondary inorganic ammonium nitrate PM, with agricultural ammonia emissions in continental Europe presenting a major driver. The findings suggest that more emphasis on reducing emissions in Europe would have marked benefits in reducing episodic PM2.5 concentrations in the UK.
Evaluating scale and roughness effects in urban flood modelling using terrestrial LIDAR data
NASA Astrophysics Data System (ADS)
Ozdemir, H.; Sampson, C. C.; de Almeida, G. A. M.; Bates, P. D.
2013-10-01
This paper evaluates the results of benchmark testing a new inertial formulation of the St. Venant equations, implemented within the LISFLOOD-FP hydraulic model, using different high resolution terrestrial LiDAR data (10 cm, 50 cm and 1 m) and roughness conditions (distributed and composite) in an urban area. To examine these effects, the model is applied to a hypothetical flooding scenario in Alcester, UK, which experienced surface water flooding during summer 2007. The sensitivities of simulated water depth, extent, arrival time and velocity to grid resolutions and different roughness conditions are analysed. The results indicate that increasing the terrain resolution from 1 m to 10 cm significantly affects modelled water depth, extent, arrival time and velocity. This is because hydraulically relevant small scale topography that is accurately captured by the terrestrial LIDAR system, such as road cambers and street kerbs, is better represented on the higher resolution DEM. It is shown that altering surface friction values within a wide range has only a limited effect and is not sufficient to recover the results of the 10 cm simulation at 1 m resolution. Alternating between a uniform composite surface friction value (n = 0.013) or a variable distributed value based on land use has a greater effect on flow velocities and arrival times than on water depths and inundation extent. We conclude that the use of extra detail inherent in terrestrial laser scanning data compared to airborne sensors will be advantageous for urban flood modelling related to surface water, risk analysis and planning for Sustainable Urban Drainage Systems (SUDS) to attenuate flow.
Evaluating scale and roughness effects in urban flood modelling using terrestrial LIDAR data
NASA Astrophysics Data System (ADS)
Ozdemir, H.; Sampson, C. C.; de Almeida, G. A. M.; Bates, P. D.
2013-05-01
This paper evaluates the results of benchmark testing a new inertial formulation of the de St. Venant equations, implemented within the LISFLOOD-FP hydraulic model, using different high resolution terrestrial LiDAR data (10 cm, 50 cm and 1 m) and roughness conditions (distributed and composite) in an urban area. To examine these effects, the model is applied to a hypothetical flooding scenario in Alcester, UK, which experienced surface water flooding during summer 2007. The sensitivities of simulated water depth, extent, arrival time and velocity to grid resolutions and different roughness conditions are analysed. The results indicate that increasing the terrain resolution from 1 m to 10 cm significantly affects modelled water depth, extent, arrival time and velocity. This is because hydraulically relevant small scale topography that is accurately captured by the terrestrial LIDAR system, such as road cambers and street kerbs, is better represented on the higher resolution DEM. It is shown that altering surface friction values within a wide range has only a limited effect and is not sufficient to recover the results of the 10 cm simulation at 1 m resolution. Alternating between a uniform composite surface friction value (n = 0.013) or a variable distributed value based on land use has a greater effect on flow velocities and arrival times than on water depths and inundation extent. We conclude that the use of extra detail inherent in terrestrial laser scanning data compared to airborne sensors will be advantageous for urban flood modelling related to surface water, risk analysis and planning for Sustainable Urban Drainage Systems (SUDS) to attenuate flow.
Estimating the CO2 mitigation potential of horizontal Ground Source Heat Pumps in the UK
NASA Astrophysics Data System (ADS)
Garcia-Gonzalez, R.; Verhoef, A.; Vidale, P. L.; Gan, G.; Chong, A.; Clark, D.
2012-04-01
By 2020, the UK will need to generate 15% of its energy from renewables to meet our contribution to the EU renewable energy target. Heating and cooling systems of buildings account for 30%-50% of the global energy consumption; thus, alternative low-carbon technologies such as horizontal Ground Couple Heat Pumps (GCHPs) can contribute to the reduction of anthropogenic CO2 emissions. Horizontal GCHPs currently represent a small fraction of the total energy generation in the UK. However, the fact that semi-detached and detached dwellings represent approximately 40% of the total housing stocks in the UK could make the widespread implementation of this technology particularly attractive in the UK and so could significantly increase its renewable energy generation potential. Using a simulation model, we analysed the dynamic interactions between the environment, the horizontal GCHP heat exchanger and typical UK dwellings, as well as their combined effect on heat pump performance and CO2 mitigation potential. For this purpose, a land surface model (JULES, Joint UK Land Environment Simulator), which calculates coupled soil heat and water fluxes, was combined with a heat extraction model. The analyses took into account the spatio-temporal variability of soil properties (thermal and hydraulic) and meteorological variables, as well as different horizontal GCHP configurations and a variety of building loads and heat demands. Sensitivity tests were performed for four sites in the UK with different climate and soil properties. Our results show that an installation depth of 1.0m would give us higher heat extractions rates, however it would be preferable to install the pipes slightly deeper to avoid the seasonal influence of variable meteorological conditions. A value of 1.5m for the spacing between coils (S) for a slinky configuration type is recommended to avoid thermal disturbances between neighbouring coils. We also found that for larger values of the spacing between the coils (S > 2), a slinky coil diameter (D) of 0.8m might be a better choice in terms of heat extraction rate. The fluid temperature of the pipe had a direct effect on the heat extraction rates of the system. The coefficient of performance of a heat pump did not remain constant and depended on the operating conditions and outdoor temperatures. The outcomes of this study will allow us to give recommendations to installers and relevant government bodies concerning the optimal configuration of future installations of horizontal GCHPs at UK developments. Finally, long-term simulations with the coupled JULES-GCHP model, using high resolution (1 km) meteorological (historical and projected data), soil physical and land cover data over the entire UK-domain, will allow us to explore the effect that global warming will have on future surface and soil temperatures, as well as soil moisture contents, and therefore its impact on the energy demand of the buildings and the CO2 mitigation potential of this type of renewable energy.
Radio-echo sounding of 'active' Antarctic subglacial lakes
NASA Astrophysics Data System (ADS)
Siegert, M. J.; Ross, N.; Blankenship, D. D.; Young, D. A.; Greenbaum, J. S.; Richter, T.; Rippin, D. M.; Le Brocq, A. M.; Wright, A.; Bingham, R.; Corr, H.; Ferraccioli, F.; Jordan, T. A.; Smith, B. E.; Payne, A. J.; Dowdeswell, J. A.; Bamber, J. L.
2013-12-01
Repeat-pass satellite altimetry has revealed 124 discrete surface height changes across the Antarctic Ice Sheet, interpreted to be caused by subglacial lake discharges (surface lowering) and inputs (surface uplift). Few of these active lakes have been confirmed by radio-echo sounding (RES) despite several attempts, however. Over the last 5 years, major geophysical campaigns have acquired RES data from several 'active' lake sites, including the US-UK-Australian ICECAP programme in East Antactica and the UK survey of the Institute Ice Stream in West Antarctica. In the latter case, a targeted RES survey of one 'active' lake was undertaken. RES evidence of the subglacial bed beneath 'active' lakes in both East and West Antarctica will be presented, and the evidence for pooled subglacial water from these data will be assessed. Based on this assessment, the nature of 'active' subglacial lakes, and their associated hydrology and relationship with surrounding topography will be discussed, as will the likelihood of further 'active' lakes in Antarctica. Hydraulic potential map of the Byrd Glacier catchment with contours at 5 MPa intervals. Predicted subglacial flowpaths are shown in blue. Subglacial lakes known from previous geophysical surveys are shown as black triangles while the newly discovered 'Three-tier lakes' are shown in dashed black outline. Surface height change features within the Byrd subglacial catchment are shown in outline and are shaded to indicate whether they were rising or falling during the ICESat campaign. Those features are labelled in-line with the numbering system of Smith et al. (J. Glac. 2009).
Large-scale lattice-Boltzmann simulations over lambda networks
NASA Astrophysics Data System (ADS)
Saksena, R.; Coveney, P. V.; Pinning, R.; Booth, S.
Amphiphilic molecules are of immense industrial importance, mainly due to their tendency to align at interfaces in a solution of immiscible species, e.g., oil and water, thereby reducing surface tension. Depending on the concentration of amphiphiles in the solution, they may assemble into a variety of morphologies, such as lamellae, micelles, sponge and cubic bicontinuous structures exhibiting non-trivial rheological properties. The main objective of this work is to study the rheological properties of very large, defect-containing gyroidal systems (of up to 10243 lattice sites) using the lattice-Boltzmann method. Memory requirements for the simulation of such large lattices exceed that available to us on most supercomputers and so we use MPICH-G2/MPIg to investigate geographically distributed domain decomposition simulations across HPCx in the UK and TeraGrid in the US. Use of MPICH-G2/MPIg requires the port-forwarder to work with the grid middleware on HPCx. Data from the simulations is streamed to a high performance visualisation resource at UCL (London) for rendering and visualisation. Lighting the Blue Touchpaper for UK e-Science - Closing Conference of ESLEA Project March 26-28 2007 The George Hotel, Edinburgh, UK
NASA Astrophysics Data System (ADS)
Ritson, J.; Bell, M.; Clark, J. M.; Graham, N.; Templeton, M.; Brazier, R.; Verhoef, A.; Freeman, C.
2013-12-01
Peatlands in the UK represent a large proportion of the soil carbon store, however there is concern that some systems may be switching from sinks to sources of carbon. The accumulation of organic material in peatlands results from the slow rates of decomposition typically occurring in these regions. Climate change may lead to faster decomposition which, if not matched by an equivalent increase in net primary productivity and litter fall, may tip the balance between source and sink. Recent trends have seen a greater flux of dissolved organic matter (DOM) from peatlands to surface waters and a change in DOM character, presenting challenges to water treatment, for example in terms of increased production of disinfectant by-products (DBPs). Peat systems border a large proportion of reservoirs in the UK so uncertainty regarding DOM quantity and quality is a concern for water utilities. This study considered five peatland vegetation types (Sphagnum spp., Calluna vulgaris, Molinea caerulea, peat soil and mixed litter) collected from the Exmoor National Park, UK where it is hypothesised that peat formation may be strongly affected by future changes to climate. A factorial experiment design to simulate climate was used, considering vegetation type, temperature and rainfall amount using a current baseline and predictions from the UKCP09 model. Gaseous fluxes of carbon were monitored over a two month period to quantify the effect on carbon mineralisation rates while 13C NMR analysis was employed to track which classes of compounds decayed preferentially. The DOM collected was characterised using UV and fluorescence techniques before being subject to standard drinking water treatment processes (coagulation/flocculation followed by chlorination). The effect of the experimental factors on DOM amenability to removal and propensity to form DBPs was then considered, with both trihalomethane (THM) and haloacetonitrile (HAN) DBP classes monitored. Initial results have shown a statistically significant (Mann-Whitney U) difference in THM formation (p<0.05) as well as the amount of DOM produced and specific UV absorption at 254nm (p<0.01) between vegetation classes.
Modelling metaldehyde in catchments: a River Thames case-study.
Lu, Q; Whitehead, P G; Bussi, G; Futter, M N; Nizzetto, L
2017-04-19
The application of metaldehyde to agricultural catchment areas to control slugs and snails has caused severe problems for drinking water supply in recent years. In the River Thames catchment, metaldehyde has been detected at levels well above the EU and UK drinking water standards of 0.1 μg l -1 at many sites across the catchment between 2008 and 2015. Metaldehyde is applied in autumn and winter, leading to its increased concentrations in surface waters. It is shown that a process-based hydro-biogeochemical transport model (INCA-contaminants) can be used to simulate metaldehyde transport in catchments from areas of application to the aquatic environment. Simulations indicate that high concentrations in the river system are a direct consequence of excessive application rates. A simple application control strategy for metaldehyde in the Thames catchment based on model results is presented.
Anderson, Zachary T; Cundy, Andrew B; Croudace, Ian W; Warwick, Phillip E; Celis-Hernandez, Omar; Stead, Jessica L
2018-06-21
Microplastics are an increasingly important contaminant in the marine environment. Depending on their composition and degree of biofouling, many common microplastics are less dense than seawater and so tend to float at or near the ocean surface. As such, they may exhibit high concentrations in the sea surface microlayer (SML - the upper 1-1000 μm of the ocean) relative to deeper water. This paper examines the accumulation of microplastics, in particular microfibres, in the SML in two contrasting estuarine systems - the Hamble estuary and the Beaulieu estuary, southern U.K., via a novel and rapid SML-selective sampling method using a dipped glass plate. Microplastic concentrations (for identified fibres, of 0.05 to 4.5 mm length) were highest in the SML-selective samples (with a mean concentration of 43 ± 36 fibres/L), compared to <5 fibres/L for surface and sub-surface bulk water samples. Data collected show the usefulness of the dipped glass plate method as a rapid and inexpensive tool for sampling SML-associated microplastics in estuaries, and indicate that microplastics preferentially accumulate at the SML in estuarine conditions (providing a potential transfer mechanism for incorporation into upper intertidal sinks). Fibres are present (and readily sampled) in both developed and more pristine estuarine systems.
NASA Astrophysics Data System (ADS)
Nickles, C.; Zhao, Y.; Beighley, E.; Durand, M. T.; David, C. H.; Lee, H.
2017-12-01
The Surface Water and Ocean Topography (SWOT) satellite mission is jointly developed by NASA, the French space agency (CNES), with participation from the Canadian and UK space agencies to serve both the hydrology and oceanography communities. The SWOT mission will sample global surface water extents and elevations (lakes/reservoirs, rivers, estuaries, oceans, sea and land ice) at a finer spatial resolution than is currently possible enabling hydrologic discovery, model advancements and new applications that are not currently possible or likely even conceivable. Although the mission will provide global cover, analysis and interpolation of the data generated from the irregular space/time sampling represents a significant challenge. In this study, we explore the applicability of the unique space/time sampling for understanding river discharge dynamics throughout the Ohio River Basin. River network topology, SWOT sampling (i.e., orbit and identified SWOT river reaches) and spatial interpolation concepts are used to quantify the fraction of effective sampling of river reaches each day of the three-year mission. Streamflow statistics for SWOT generated river discharge time series are compared to continuous daily river discharge series. Relationships are presented to transform SWOT generated streamflow statistics to equivalent continuous daily discharge time series statistics intended to support hydrologic applications using low-flow and annual flow duration statistics.
Zakkour, P D; Gaterell, M R; Griffin, P; Gochin, R J; Lester, J N
2002-10-01
Increasing political effort to improve water quality across the UK and Europe has led to water and sewerage companies investing heavily in high-tech wastewater treatment plants capable of producing high quality effluents. Consequently, amounts of bought-in electricity used for wastewater treatment has and will continue to increase significantly over coming years, while greater provision of enhanced sewage treatment also produces greater volumes of sewage sludge requiring treatment and disposal. Over the same period, tougher controls on the quality of biosolids applied to agricultural land have also been introduced, while there has been an international attempt to reduce the use of fossil-fuel derived power sources because of concerns over global warming. The latter has brought about the introduction of financial instruments, such as the Climate Change Levy, to curb energy use, promote energy efficiency and encourage the development of renewable energy technologies. These factors are set to drive-up the costs of providing adequate sewage treatment services, while at the same time, a tough regulatory line taken to control profits on regional monopolies held by the UK water companies will significantly reduce their revenues over the period 2000-05. The result is that, financially, UK water and sewerage companies face their most challenging period since privatisation in 1989. This paper briefly outlines the current regulations relating to water quality and energy use that will affect water company operations over coming years.
Integrated Land-Water-Energy assessment using the Foreseer Tool
NASA Astrophysics Data System (ADS)
Allwood, Julian; Konadu, Dennis; Mourao, Zenaida; Lupton, Rick; Richards, Keith; Fenner, Richard; Skelton, Sandy; McMahon, Richard
2016-04-01
This study presents an integrated energy and resource modelling and visualisation approach, ForeseerTM, which characterises the interdependencies and evaluates the land and water requirement for energy system pathways. The Foreseer Tool maps linked energy, water and land resource futures by outputting a set of Sankey diagrams for energy, water and land, showing the flow from basic resource (e.g. coal, surface water, and forested land) through transformations (e.g. fuel refining and desalination) to final services (e.g. sustenance, hygiene and transportation). By 'mapping' resources in this way, policy-makers can more easily understand the competing uses through the identification of the services it delivers (e.g. food production, landscaping, energy), the potential opportunities for improving the management of the resource and the connections with other resources which are often overlooked in a traditional sector-based management strategy. This paper will present a case study of the UK Carbon Plan, and highlights the need for integrated resource planning and policy development.
High temporal resolution water chemistry information for catchment understanding and management
NASA Astrophysics Data System (ADS)
Reaney, S. M.; Deasy, C.; Ockenden, M.; Perks, M.; Quinton, J.
2013-12-01
Many rivers and lakes are currently not meeting their full ecological potential due to environmental pressures including non-point source pollution from the catchment. These pressures include sediment, nitrogen and phosphorus from agriculture and other sources. Each of these pollutants is transferred through the landscape with different hydrological processes and along different pathways. Therefore, to effectively select and spatially target mitigation actions in the landscape, an understanding of the dominant hydrological processes and dynamics which are causing the transfer of material is required. Recent advances in environmental monitoring have enabled the collection of new rich datasets with a high temporal sampling frequency. In the UK, these techniques have been implemented in the Defra Demonstration Test Catchments project and with Natural England for targeted site investigations. Measurements include weather, hydrological flows, sediment, oxygen isotopes, nitrogen and phosphorus from a combination of in-field labs, water chemistry sondes and storm samplers. The detailed time series data can then be analysed to give insights into catchment processes through the analysis of the measured process dynamics. For example, evidence of the transfer of material along surface (or pipe) flow paths can be found from the co-incident timing of the sediment and flow record, or the timing of temperature variations after a storm event can give insight into the contribution of shallow groundwater. Given this evidence of catchment hydrological dynamics it is possible to determine the probable pathways which are transferring pollutants and hence it is possible to select suitable mitigation options in the landscape to improve the river or lake. For example, evidence of a pollutant transfer occurring as shallow soil flows suggests that buffer strips would not be an effective solution since these measures intercept surface pathways. Information on catchment residence time not only gives insight into the pathway but also gives information on the likely amount of time required for an improvement in water quality to occur. Therefore, the success or failure of a scheme can be assessed at an appropriate time after the works rather than prematurely. These insights into catchment processes enable us to understand the systems in greater depth and crucially to communicate this understanding to the local stakeholders. The greater evidence of the system behaviour can then be used to prompt uptake of the mitigation features and hence lead to environmental and ecological improvements. Funding from Defra UK and Natural England, UK.
Soil hydrophobicity - relating effects at atomic, molecular, core and national scales
NASA Astrophysics Data System (ADS)
Matthews, Peter; Doerr, Stefan; Van Keulen, Geertje; Dudley, Ed; Francis, Lewis; Whalley, Richard; Gazze, Andrea; Hallin, Ingrid; Quinn, Gerry; Sinclair, Kat; Ashton, Rhys
2016-04-01
The detrimental impacts of soil hydrophobicity include increased runoff, erosion and flooding, reduced biomass production, inefficient use of irrigation water and preferential leaching of pollutants. Its impacts may exacerbate flood risk associated with more extreme drought and precipitation events predicted with UK climate change scenarios. The UK's Natural Environment Research Council (NERC) has therefore funded a major research programme to investigate soil hydrophobicity over length scales ranging from atomic through molecular, core and landscape scale. This presentation gives an overview of the findings to date. The programme is predicated on the hypothesis that changes in soil protein abundance and localization, induced by variations in soil moisture and temperature, are crucial driving forces for transitions between hydrophobic and hydrophilic conditions at soil particle surfaces. Three soils were chosen based on the severity of hydrophobicity that can be achieved in the field: severe to extreme (Cefn Bryn, Gower, Wales), intermediate to severe (National Botanical Garden, Wales), and subcritical (Park Grass, Rothamsted Research near London). The latter is already highly characterised so was also used as a control. Hydrophobic/ hydrophilic transitions were measured from water droplet penetration times. Scientific advances in the following five areas will be described: (i) the identification of these soil proteins by proteomic methods, using a novel separation method which reduces interference by humic acids, and allows identification by ESI and MALDI TOF mass spectrometry and database searches, (ii) the examination of such proteins, which form ordered hydrophobic ridges, and measurement of their elasticity, stickiness and hydrophobicity at nano- to microscale using atomic force microscopy adapted for the rough surfaces of soil particles, (iii) the novel use of a picoliter goniometer to show hydrophobic effects at a 1 micron diameter droplet level, which avoids the averaging over soil cores and particles evident in microliter goniometry, with which the results are compared, (iv) measurements at core scale using water retention and wicking experiments, and (v) the interpretation, integration and upscaling of the results using a development of the PoreXpert void network model, a significant advance on the Van Genuchten approach. An explanation will also be given as to how the results will be incorporated into the JULES hydrological model of the UK Meteorological Office, used to predict flooding for different soil types and usage.
NASA Astrophysics Data System (ADS)
Ragab, R.; Rosier, P.; Dixon, A.; Bromley, J.; Cooper, J. D.
2003-08-01
Lack of accurate data has led some hydrologists and city planners to assume that urban infiltration is zero and runoff is 100% of the rainfall. These assumptions lead to an over estimation of road runoff volume and an underestimation of direct recharge to groundwater, which is already rising under some UK cities. This study investigates infiltration and runoff processes and quantifies the percentage of rainfall that contributes to storm drainage, and that which infiltrates through different types of road surface. Access tubes were installed for measuring soil water content using a neutron probe in three car parks, a road and a grass site at the Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford. Storm drainage was recorded at the exit of the Thamesmead Estate in Crowmarsh Gifford, just before the drain joins the River Thames at Wallingford. Rainfall and water table depth were also recorded. Weekly measurements of soil moisture content indicated that the top 40 cm layer is not influenced by water-table fluctuations and, therefore, positive changes in soil moisture could be attributed to infiltration of rainfall through the surface. Depending on the nature of the surface, subsurface layers, level of traffic, etc., between 6 and 9% of rainfall was found to infiltrate through the road surfaces studied. The storm drainage generated by road runoff revealed a flow pattern similar to that of the receiving watercourse (River Thames) and increased with the increase of infiltration and soil water content below the road surface. The ratio of runoff to rainfall was 0·7, 0·9 and 0·5 for annual, winter (October-March) and summer (April-September) respectively. As the results of the infiltration indicated that 6 to 9% of annual rainfall infiltrates through the road surface, this means that evaporation represents, 21-24% of annual rainfall, with more evaporation taking place during summer than winter.
NASA Astrophysics Data System (ADS)
Dolan, Tom; Pullan, Stephanie; Whelan, Mick; Parsons, David
2013-04-01
Diffuse inputs from agriculture are commonly the main source of pesticide contamination in surface water and may have implications for the quality of treated drinking water. After privatisation in 1991, UK water companies primarily focused on the provision of sufficient water treatment to reduce the risk of non-compliance with the European Drinking Water Directive (DWD), under which all pesticide concentrations must be below 0.1µg/l and UK Water Supply Regulations for the potable water they supply. Since 2000, Article 7 of the Water Framework Directive (WFD) has begun to drive a prevention-led approach to compliance with the DWD. As a consequence water companies are now more interested in the quality of 'raw' (untreated) water at the point of abstraction. Modelling (based upon best available estimates of cropping, pesticide use, weather conditions, pesticide characteristics, and catchment characteristics) and monitoring of raw water quality can both help to determine the compliance risks associated with the quality of this 'raw' water resource. This knowledge allows water companies to prioritise active substances for action in their catchments, and is currently used in many cases to support the design of monitoring programmes for pesticide active substances. Additional value can be provided if models are able to help to identify the type and scale of catchment management interventions required to achieve DWD compliance for pesticide active substances through pollution prevention at source or along transport pathways. These questions were explored using a simple catchment-scale pesticide fate and transport model. The model employs a daily time-step and is semi-lumped with calculations performed for soil type and crop combinations, weighted by their proportions within the catchment. Soil properties are derived from the national soil database and the model can, therefore, be applied to any catchment in England and Wales. Various realistic catchment management intervention scenarios were explored (including changes to land use and pesticide usage) with the aim of providing a useful input to the debate between water companies, their regulators and pesticide users over the scale of catchment management required to support both DWD and WFD Article 7 compliance.
NASA Astrophysics Data System (ADS)
Gould, Jessica; Kienast, Markus; Dowd, Michael
2017-05-01
Alkenone unsaturation, expressed as the UK37' index, is closely related to growth temperature of prymnesiophytes, thus providing a reliable proxy to infer past sea surface temperatures (SSTs). Here we address two lingering uncertainties related to this SST proxy. First, calibration models developed for core-top sediments and those developed for surface suspended particulates organic material (SPOM) show systematic offsets, raising concerns regarding the transfer of the primary signal into the sedimentary record. Second, questions remain regarding changes in slope of the UK37' vs. growth temperature relationship at the temperature extremes. Based on (re)analysis of 31 new and 394 previously published SPOM UK37' data from the Atlantic Ocean, a new regression model to relate UK37' to SST is introduced; the Richards curve (Richards, 1959). This non-linear regression model provides a robust calibration of the UK37' vs. SST relationship for Atlantic SPOM samples and uniquely accounts for both the fact that the UK37' index is a proportion, and so must lie between 0 and 1, as well as for the observed reduction in slope at the warm and cold ends of the temperature range. As with prior fits of SPOM UK37' vs. SST, the Richards model is offset from traditional regression models of sedimentary UK37' vs. SST. We posit that (some of) this offset can be attributed to the seasonally and depth biased sampling of SPOM material.
Turner, Andrew D.; Higgins, Cowan; Davidson, Keith; Veszelovszki, Andrea; Payne, Daniel; Hungerford, James; Higman, Wendy
2015-01-01
Regular occurrence of brevetoxin-producing toxic phytoplankton in commercial shellfishery areas poses a significant risk to shellfish consumer health. Brevetoxins and their causative toxic phytoplankton are more limited in their global distribution than most marine toxins impacting commercial shellfisheries. On the other hand, trends in climate change could conceivably lead to increased risk posed by these toxins in UK waters. A request was made by UK food safety authorities to examine these toxins more closely to aid possible management strategies, should they pose a threat in the future. At the time of writing, brevetoxins have been detected in the Gulf of Mexico, the Southeast US coast and in New Zealand waters, where regulatory levels for brevetoxins in shellfish have existed for some time. This paper reviews evidence concerning the prevalence of brevetoxins and brevetoxin-producing phytoplankton in the UK, together with testing methodologies. Chemical, biological and biomolecular methods are reviewed, including recommendations for further work to enable effective testing. Although the focus here is on the UK, from a strategic standpoint many of the topics discussed will also be of interest in other parts of the world since new and emerging marine biotoxins are of global concern. PMID:25775421
NASA Astrophysics Data System (ADS)
Khim, B.; Ikehara, K.; Sagawa, T.; Shibahara, A.; Yamamoto, M.
2010-12-01
Laminated sediments during the last deglaciation in the subarctic North Pacific indicate significant depletion of dissolved oxygen concentration at intermediate water depths. Such a strong oxygen minimum zone results primarily from a combination of high surface water productivity and poor ventilation of intermediate waters. We investigated a variety of paleoclimatic proxies using about 8-m long piston core sediment (GH02-1030; 42o13.770N, 144o12.530E; water depth, 1212 m) obtained from the continental slope off Tokachi (eastern Hokkaido Island), which is the main path of the southwestward Oyashio Current in the subarctic Northwest Pacific. Laminated sediments were identified at the two horizons in the core GH02-1030; the upper one at 11.4-12.2 cal.kyr BP and the lower one at 14.1-14.7 cal.kyr BP, corresponding to Bølling-Allerød (B/A) and Preboreal (PB), respectively. Between these laminated layers, Younger Dryas occurred. Both laminated sediment layers are characterized by Bolivina tumida, B. pacifica, and Buliminella tenuata, indicating dysoxic bottom water conditions. Increased Mg/Ca-derived intermediate-water temperature and δ18OW values at B/A and PB periods suggest the poor ventilation of intermediate water because of the surface water freshening (i.e., decrease of surface-water salinity). UK'37-derived temperature record also supports the increase of surface-water temperature during B/A and PB intervals. During the last deglaciation, short-chain C14-C18 n-fatty acids, derived mainly from marine organisms, showed higher concentrations, indicating the increased surface-water production, and at the same time, abundant lignin reflected more contribution of terrigenous organic matter, supporting increased freshwater discharge. Variation of CaCO3 contents show remarkable double peaks, corresponding to B/A and PB periods, respectively, leading to the increase of TOC contents. Opal contents also follow similar pattern to CaCO3 contents, but are much less than the Holocene values. Interesting are the remarkable double peaks of δ15N values, also corresponding to B/A and PB intervals, respectively. Such increased δ15N values indicated the enhanced nitrate utilization through the promoted phytoplankton production. Otherwise, the high δ15N records could be indicative of water column denitrification in the source region. Thus, our study area possibly experienced high surface water productivity at times of reduced intermediate ventilation in the subarctic Northwest Pacific during the last deglaciation.
Risks posed by climate change to the delivery of Water Framework Directive objectives in the UK.
Wilby, R L; Orr, H G; Hedger, M; Forrow, D; Blackmore, M
2006-12-01
The EU Water Framework Directive (WFD) is novel because it integrates water quality, water resources, physical habitat and, to some extent, flooding for all surface and groundwaters and takes forward river basin management. However, the WFD does not explicitly mention risks posed by climate change to the achievement of its environmental objectives. This is despite the fact that the time scale for the implementation process and achieving particular objectives extends into the 2020s, when climate models project changes in average temperature and precipitation. This paper begins by reviewing the latest UK climate change scenarios and the wider policy and science context of the WFD. We then examine the potential risks of climate change to key phases of the River Basin Management Process that underpin the WFD (such as characterisation of river basins and their water bodies, risk assessments to identify pressures and impacts, programmes of measures (POMs) options appraisal, monitoring and modelling, policy and management activities). Despite these risks the WFD could link new policy and participative mechanisms (being established for the River Basin Management Plans) to the emerging framework of national and regional climate change adaptation policy. The risks are identified with a view to informing policy opportunities, objective setting, adaptation strategies and the research agenda. Key knowledge gaps have already been identified during the implementation of the WFD, such as the links between hydromorphology and ecosystem status, but the overarching importance of linking climate change to these considerations needs to be highlighted. The next generation of (probabilistic) climate change scenarios will present new opportunities and challenges for risk analysis and policy-making.
Trends in evaporation loss over the UK: 1962 to 2013
NASA Astrophysics Data System (ADS)
Blyth, Eleanor; Robinson, Emma; Martinez de la Torre, Alberto
2017-04-01
Many models of hydrology assume that an increase in air temperature will result in an increase in evaporation. However, there are some processes involved in transpiration (evaporation through the vegetation) that make the relationship more complicated: in a bid to conserve water, vegetation will reduce their stomata in response to drier soils and warmer drier air which leads to lower transpiration rates despite higher evaporative demands. In addition, the vegetation responds to increases in atmospheric carbon dioxide by closing their stomata, and this further reduces the transpiration. The JULES (Joint UK Land Environment Simulator) model, used widely in the UK to study the impacts of climate change on the environment, includes many of the processes that are likely to affect changes in water loss and its impact on large scale hydrology. A new assessment of the UK wide water balance for the last 52 years (1961 to 2013) at a 1km grid-scale has been made using this model in a system called CHESS (Climate Hydrology and Ecology research Support System). Some data is available to check the overall water balance. For instance, river flow data can be used at an annual time scale to capture the water balance, while evaporation data from flux towers can be used at some locations around the UK for the few years that it is available to evaluate the seasonal variations of evaporation. Both of these methods provide imperfect but useful evidence. Here we present the results of the modelling exercise and the evaluation: long term increasing evaporation loss trends are clearly present in the model output and these are discussed with respect to the different drivers of change.
NASA Astrophysics Data System (ADS)
Vieno, M.; Heal, M. R.; Hallsworth, S.; Famulari, D.; Doherty, R. M.; Dore, A. J.; Tang, Y. S.; Braban, C. F.; Leaver, D.; Sutton, M. A.; Reis, S.
2013-12-01
Surface concentrations of secondary inorganic particle components over the UK have been analysed for 2001-2010 using the EMEP4UK regional atmospheric chemistry transport model. In early 2003 an episode of substantially elevated surface concentrations of ammonium nitrate was measured across the UK by the AGANET network. The EMEP4UK model was able accurately to represent both the long-term decadal surface concentrations and the episode in 2003. The latter was identified as consisting of three separate episodes, each of less than 1 month duration, in February, March and April. The primary cause of the elevated nitrate levels across the UK was meteorological, a persistent high pressure system, but whose varying location impacted the relative importance of transboundary vs. domestic emissions. Whilst long-range transport dominated the elevated nitrate in February, in contrast it was domestic emissions that mainly contributed to the March episode, and for the April episode both domestic emissions and long-range transport contributed. A prolonged episode such as the one in early 2003 can have substantial impact on annual average concentrations. The episode led to annual concentration differences at the regional scale of similar magnitude to those driven by long-term changes in precursor emissions over the full decade investigated here. The results demonstrate that a substantial part of the UK, particularly the south and south-east, may be close to or actually exceeding annual mean limit values because of import of inorganic aerosol components from continental Europe under specific conditions. The results reinforce the importance of employing multiple year simulations in the assessment of emissions reduction scenarios on PM concentrations and the need for international agreements to address the transboundary component of air pollution.
Olszewska, Justyna P; Heal, Kate V; Winfield, Ian J; Eades, Lorna J; Spears, Bryan M
2017-10-15
Red mud is a by-product of alumina production. Little is known about the long-term fate of red mud constituents in fresh waters or of the processes regulating recovery of fresh waters following pollution control. In 1983, red mud leachate was diverted away from Kinghorn Loch, UK, after many years of polluting this shallow and monomictic lake. We hypothesised that the redox-sensitive constituents of red mud leachate, phosphorus (P), arsenic (As) and vanadium (V), would persist in the Kinghorn Loch for many years following pollution control as a result of cycling between the lake bed sediment and the overlying water column. To test this hypothesis, we conducted a 12-month field campaign in Kinghorn Loch between May 2012 and April 2013 to quantify the seasonal cycling of P, As, and V in relation to environmental conditions (e.g., dissolved oxygen (DO) concentration, pH, redox chemistry and temperature) in the lake surface and bottom waters. To confirm the mechanisms for P, As and V release, a sediment core incubation experiment was conducted using lake sediment sampled in July 2012, in which DO concentrations were manipulated to create either oxic or anoxic conditions similar to the bed conditions found in the lake. The effects on P, As, and V concentrations and species in the water column were measured daily over an eight-day incubation period. Phosphate (PO 4 -P) and dissolved As concentrations were significantly higher in the bottom waters (75.9 ± 30.2 μg L -1 and 23.5 ± 1.83 μg L -1 , respectively) than in the surface waters (12.9 ± 1.50 μg L -1 and 14.1 ± 2.20 μg L -1 , respectively) in Kinghorn Loch. Sediment release of As and P under anoxic conditions was confirmed by the incubation experiment and by the significant negative correlations between DO and P and As concentrations in the bottom waters of the lake. In contrast, the highest dissolved V concentrations occurred in the bottom waters of Kinghorn Loch under oxic conditions (15.0 ± 3.35 μg L -1 ), with the release from the bed sediment apparently being controlled by a combination of competitive ion concentrations, pH and redox conditions. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Determining the location of buried plastic water pipes from measurements of ground surface vibration
NASA Astrophysics Data System (ADS)
Muggleton, J. M.; Brennan, M. J.; Gao, Y.
2011-09-01
‘Mapping the Underworld' is a UK-based project, which aims to create a multi-sensor device that combines complementary technologies for remote buried utility service detection and location. One of the technologies to be incorporated in the device is low-frequency vibro-acoustics, and techniques for detecting buried infrastructure, in particular plastic water pipes, are being investigated. One of the proposed techniques involves excitation of the pipe at some known location with concurrent vibrational mapping of the ground surface in order to infer the location of the remainder of the pipe. In this paper, measurements made on a dedicated pipe rig are reported. Frequency response measurements relating vibrational velocity on the ground to the input excitation were acquired. Contour plots of the unwrapped phase revealed the location of the pipe to within 0.1-0.2 m. Magnitude contour plots revealed the excitation point and also the location of the pipe end. By examining the unwrapped phase gradients along a line above the pipe, it was possible to identify the wave-type within the pipe responsible for the ground surface vibration. Furthermore, changes in the ground surface phase speed computed using this method enabled the location of the end of the pipe to be confirmed.
Final Report for DOE Support of 5th the International Workshop on Oxide Surfaces (IWOX-V)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Charles T. Campbell
The 5th International Workshop on Oxide Surfaces (IWOX-V) was held at Granlibakken Conference center in Lake Tahoe, CA, January 7-12. The total attendance was ~90. The breakdown of attendees by country is as follows: USA 41 Germany 18 Japan 7 UK 5 Italy 5 France 4 Austria 3 Denmark 3 Cech. Repub. 1 Ireland 1 New Zealand 1 India 1 The technical program included oral sessions on the electronic and magnetic properties of oxide surfaces, surface and interface structure, advances in theory, surface defects, thin film oxides on metals and on oxides, thin film metals on oxides, surface photochemistry, surfacemore » reactivity, and interactions with water. Two evening poster sessions had similar themes. As in previous years, the program stimulated significant interest and discussion among the attendees. The local expenses (food and lodging, $918 per person) for eight foreign invited speakers were covered by BES funds. In addition, partial reimbursement for travel ($328 per person) was supported by BES funds for two more foreign invited speakers.« less
Grayson, Richard; Kay, Paul; Foulger, Miles
2008-01-01
Diffuse pollution poses a threat to water quality and results in the need for treatment for potable water supplies which can prove costly. Within the Yorkshire region, UK, nitrates, pesticides and water colour present particular treatment problems. Catchment management techniques offer an alternative to 'end of pipe' solutions and allow resources to be targeted to the most polluting areas. This project has attempted to identify such areas using GIS based modelling approaches in catchments where water quality data were available. As no model exists to predict water colour a model was created using an MCE method which is capable of predicting colour concentrations at the catchment scale. CatchIS was used to predict pesticide and nitrate N concentrations and was found to be generally capable of reliably predicting nitrate N loads at the catchment scale. The pesticides results did not match the historic data possibly due to problems with the historic pesticide data and temporal and spatially variability in pesticide usage. The use of these models can be extended to predict water quality problems in catchments where water quality data are unavailable and highlight areas of concern. IWA Publishing 2008.
Murrell, Sarah; Marshall, Teresa A.; Moynihan, Paula J.; Qian, Fang; Wefel, James S.
2009-01-01
Summary Objective Our objective was to compare the physiochemical properties and erosion potentials between beverages available in the UK and the US. Methods The physiochemical properties (pH, titratable acidity and fluoride concentration) and erosion potential on enamel surfaces of beverages available in the UK were compared to similar beverages from the US. Enamel windows were exposed to beverages for 25 hours. Teeth were sectioned through the windows, and lesion depths were defined as the average distance between the original tooth structure and the base of demineralization. Results The pH was lower in UK apple juice, orange juice, Diet Pepsi® and Sprite Zero® (p<0.05), and higher in UK orange soda and diet orange soda than in similar US beverages (p<0.05). Titratable acidities were higher in UK apple juice, orange juice, orange soda, diet orange soda and Sprite® (p<0.01), and lower in UK Sunny D® than in the US counterpart (p<0.001). Fluoride concentrations were lower in UK apple juice, orange juice, Coke®, and Diet Coke®, Sprite® and Sprite Zero® (p<0.001), and higher in UK orange soda, diet orange soda, Pepsi® and Diet Pepsi® than in their US counterparts (p<0.001). Lesion depths were higher in UK apple juice, orange juice, Diet Coke®, Sprite® and Sprite Zero® than in their US counterparts (p<0.05). Lesion depths were associated with pH (p=0.010) and country of origin (p=0.002). Conclusions Under similar laboratory conditions, the physiochemical properties and erosion potentials on enamel surfaces differed between some, but not all, beverages available in the UK and the US. PMID:19962418
Murrell, Sarah; Marshall, Teresa A; Moynihan, Paula J; Qian, Fang; Wefel, James S
2010-04-01
Our objective was to compare the physiochemical properties and erosion potentials between beverages available in the UK and the US. The physiochemical properties (pH, titratable acidity and fluoride concentration) and erosion potential on enamel surfaces of beverages available in the UK were compared to similar beverages from the US. Enamel windows were exposed to beverages for 25h. Teeth were sectioned through the windows, and lesion depths were defined as the average distance between the original tooth structure and the base of demineralization. The pH was lower in UK apple juice, orange juice, Diet Pepsi and Sprite Zero (p<0.05), and higher in UK orange soda and diet orange soda than in similar US beverages (p<0.05). Titratable acidities were higher in UK apple juice, orange juice, orange soda, diet orange soda and Sprite (p<0.01), and lower in UK Sunny D than in the US counterpart (p<0.001). Fluoride concentrations were lower in UK apple juice, orange juice, Coke, and Diet Coke, Sprite and Sprite Zero (p<0.001), and higher in UK orange soda, diet orange soda, Pepsi and Diet Pepsi than in their US counterparts (p<0.001). Lesion depths were higher in UK apple juice, orange juice, Diet Coke, Sprite and Sprite Zero than in their US counterparts (p<0.05). Lesion depths were associated with pH (p=0.010) and country of origin (p=0.002). Under similar laboratory conditions, the physiochemical properties and erosion potentials on enamel surfaces differed between some, but not all, beverages available in the UK and the US. Copyright 2009 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Dobson, B.; Pianosi, F.; Wagener, T.
2016-12-01
Extensive scientific literature exists on the study of how operation decisions in water resource systems can be made more effectively through the use of optimization methods. However, to the best of the authors' knowledge, there is little in the literature on the implementation of these optimization methods by practitioners. We have performed a survey among UK reservoir operators to assess the current state of method implementation in practice. We also ask questions to assess the potential for implementation of operation optimization. This will help academics to target industry in their current research, identify any misconceptions in industry about the area and open new branches of research for which there is an unsatisfied demand. The UK is a good case study because the regulatory framework is changing to impose "no build" solutions for supply issues, as well as planning across entire water resource systems rather than individual components. Additionally there is a high appetite for efficiency due to the water industry's privatization and most operators are part of companies that control multiple water resources, increasing the potential for cooperation and coordination.
Planetary Penetrators - The Vanguard for the Future Exploration of the Solar System
NASA Astrophysics Data System (ADS)
Collinson, G.; UK Penetrator Consortium
The UK Penetrator Consortium is aiming to develop spacecraft weighing <15 kg, rugged enough to survive impacts with planetary surfaces at speeds of up to 300 m/s and bury themselves a few meters into the surface. A full-scale trial is currently under preparation, leading towards a proposed Lunar mission, called “MoonLITE”, early next decade. Detectors for volatiles aboard MoonLITE will search for the presence of lunar water, whilst seismometers will measure the strength and frequency of moonquakes over the mission's nominal one-year period and probe the internal structure of the moon using simultaneous measurements of seismic waves that travel through the lunar interior. The consortium also has long term plans for more ambitious missions to Jupiter's moon of Europa, and Saturn's Moons of Titan and Enceladus as part of ESA's Cosmic Visions Programme. Key goals include the search for sub-surface oceans, the study of sub-surface geochemistry and seismic activity and the search for organic molecules of exobiological importance.
NASA Astrophysics Data System (ADS)
Green, Daniel; Pattison, Ian; Yu, Dapeng
2017-04-01
Surface water (pluvial) flooding occurs when excess rainfall from intense precipitation events is unable to infiltrate into the subsurface or drain via natural or artificial drainage channels. Surface water flood events pose a major hazard to urban regions across the world, with nearly two thirds of flood damages in the UK being caused by surface water flood events. The perceived risk of surface water flooding appears to have increased in recent years due to several factors, including (i) precipitation increases associated with climatic change and variability; (ii) population growth meaning more people are occupying flood risk areas, and; (iii) land-use changes. Because urban areas are often associated with a high proportion of impermeable land-uses (e.g. tarmacked or paved surfaces and buildings) and a reduced coverage of vegetated, permeable surfaces, urban surface water flood risk during high intensity precipitation events is often exacerbated. To investigate the influence of urbanisation and terrestrial factors on surface water flood outputs, rainfall intensity, catchment slope, permeability, building density/layout scenarios were designed within a novel, 9m2 physical modelling environment. The two-tiered physical model used consists of (i) a low-cost, nozzle-type rainfall simulator component which is able to simulate consistent, uniformly distributed rainfall events of varying duration and intensity, and; (ii) a reconfigurable, modular plot surface. All experiments within the physical modelling environment were subjected to a spatiotemporally uniform 45-minute simulated rainfall event, while terrestrial factors on the physical model plot surface were altered systematically to investigate their hydrological response on modelled outflow and depth profiles. Results from the closed, controlled physical modelling experiments suggest that meteorological factors, such as the duration and intensity of simulated rainfall, and terrestrial factors, such as model slope, surface permeability and building density have a significant influence on physical model hydrological outputs. For example, changes in building density across the urban model catchment are shown to result in hydrographs having (i) a more rapid rising limb; (ii) higher peak discharges; (iii) a reduction in the total hydrograph time, and; (iv) a faster falling limb, with the dense building scenario having a 22% increase in peak discharge when compared to the no building scenario. Furthermore, the layout of buildings across the plot surface and their proximity to the outflow unit (i.e. downstream, upstream or to the side of the physical model outlet) is shown to influence outflow hydrograph response, with downstream concentrated building scenarios resulting in a delay in hydrograph onset time and a reduction in the time of the total outflow hydrograph event.
City-scale accessibility of emergency responders operating during flood events
NASA Astrophysics Data System (ADS)
Green, Daniel; Yu, Dapeng; Pattison, Ian; Wilby, Robert; Bosher, Lee; Patel, Ramila; Thompson, Philip; Trowell, Keith; Draycon, Julia; Halse, Martin; Yang, Lili; Ryley, Tim
2017-01-01
Emergency responders often have to operate and respond to emergency situations during dynamic weather conditions, including floods. This paper demonstrates a novel method using existing tools and datasets to evaluate emergency responder accessibility during flood events within the city of Leicester, UK. Accessibility was quantified using the 8 and 10 min legislative targets for emergency provision for the ambulance and fire and rescue services respectively under "normal" no-flood conditions, as well as flood scenarios of various magnitudes (1 in 20-year, 1 in 100-year and 1 in 1000-year recurrence intervals), with both surface water and fluvial flood conditions considered. Flood restrictions were processed based on previous hydrodynamic inundation modelling undertaken and inputted into a Network Analysis framework as restrictions for surface water and fluvial flood events. Surface water flooding was shown to cause more disruption to emergency responders operating within the city due to its widespread and spatially distributed footprint when compared to fluvial flood events of comparable magnitude. Fire and rescue 10 min accessibility was shown to decrease from 100, 66.5, 39.8 and 26.2 % under the no-flood, 1 in 20-year, 1 in 100-year and 1 in 1000-year surface water flood scenarios respectively. Furthermore, total inaccessibility was shown to increase with flood magnitude from 6.0 % under the 1 in 20-year scenario to 31.0 % under the 1 in 100-year flood scenario. Additionally, the evolution of emergency service accessibility throughout a surface water flood event is outlined, demonstrating the rapid impact on emergency service accessibility within the first 15 min of the surface water flood event, with a reduction in service coverage and overlap being observed for the ambulance service during a 1 in 100-year flood event. The study provides evidence to guide strategic planning for decision makers prior to and during emergency response to flood events at the city scale. It also provides a readily transferable method for exploring the impacts of natural hazards or disruptions in other cities or regions based on historic, scenario-based events or real-time forecasting, if such data are available.
Willis, C; Elviss, N; Aird, H; Fenelon, D; McLauchlin, J
2012-08-01
To investigate hygiene practices of caterers at large events in order to: support the production of guidance on catering at such events; to compare hygiene standards at weekends with other times in the week; and to learn lessons in preparation for the London Olympics in 2012. UK-wide study of caterers at large events, including questionnaires on hygiene procedures and microbiological examination of food, water and environmental samples. In total, 1364 samples of food, water, surface swabs and cloths were collected at 139 events, by local authority sampling officers, and transported to laboratories for microbiological analysis. Eight percent of food samples were of an unsatisfactory quality, and a further 2% contained potentially hazardous levels of Bacillus spp. A significantly higher proportion of unsatisfactory food samples were taken from vendors without adequate food safety procedures in place. Fifty-two percent of water samples, 38% of swabs and 71% of cloths were also unsatisfactory. The majority of samples (57%) were collected on Saturdays, Sundays or bank holidays. Environmental swab results were significantly poorer at weekends compared with other days of the week. This study reinforces the fact that food hygiene is a continuing cause for concern in mobile vendors, and indicates a need for an ongoing programme of training and monitoring of caterers in preparation for the London Olympics. Copyright © 2012 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Raper, E; Davies, S; Perkins, B; Lamb, H; Hermanson, M; Soares, A; Stephenson, T
2015-06-01
Slag, a by-product from the iron and steel industry, has a range of applications within construction and is used in wastewater treatment. Historically considered a waste material, little consideration was given to the environmental impacts of its disposal. South Gare (a Site of Special Scientific Interest) located at the mouth of the Tees estuary, UK, formed on slag deposits used to create a sea wall and make the land behind permanent. Over time, ponds formed in depressions with the water chemistry, being significantly impacted by the slag deposits. Calcium levels reached 504 mg/L, nitrate 49.0 mg/L and sulphate 1,698 mg/L. These levels were also reflected in the composition of the sediment. pH (5.10-9.90) and electrical conductivity (2,710-3,598 µS/cm) were variable but often notably high. Pb, Cu and Cd were not present within the water, whilst Zn ranged from 0.027 to 0.37 mg/L. Heavy metal levels were higher in surface sediments. Zinc was most dominant (174.3-1,310.2 mg/L) followed by Pb (9.9-431 mg/L), Cu (8.4-41.8 mg/L) and Cd (0.4-1.1 mg/L). A sediment core provided a historical overview of the ponds. The ponds were unfavourable for aquatic biodiversity and unsuitable for drinking water abstraction.
Genetic isolation of a now extinct population of bottlenose dolphins (Tursiops truncatus)
Nichols, Courtney; Herman, Jerry; Gaggiotti, Oscar E; Dobney, Keith M; Parsons, Kim; Hoelzel, A. Rus
2007-01-01
A number of dolphin species, though highly mobile, show genetic structure among parapatric and sometimes sympatric populations. However, little is known about the temporal patterns of population structure for these species. Here, we apply Bayesian inference and data from ancient DNA to assess the structure and dynamics of bottlenose dolphin (Tursiops truncatus) populations in the coastal waters of the UK. We show that regional population structure in UK waters is consistent with earlier studies suggesting local habitat dependence for this species in the Mediterranean Sea and North Atlantic. One genetically differentiated UK population went extinct at least 100 years ago and has not been replaced. The data indicate that this was a local extinction, and not a case of historical range shift or contraction. One possible interpretation is a declining metapopulation and conservation need for this species in the UK. PMID:17456457
NASA Astrophysics Data System (ADS)
Harning, D.; Sepúlveda, J.; Andrews, J. T.; Cabedo-Sanz, P.; Belt, S. T.; Marchitto, T. M.; Stoner, J. S.; Geirsdóttir, Á.; Miller, G. H.
2017-12-01
Icelandic climate is vulnerable to variations in the dominance of competing Arctic and Atlantic ocean currents. The boundary between these water masses delineates the Polar Front, which today occupies the North Iceland Shelf (NIS). To date, Holocene oceanographic reconstructions along the NIS have employed a variety of proxies including Mg/Ca and δ18O of benthic and planktonic foraminifera, quartz and calcite wt%, the alkenone unsaturation index (Uk'37) and biotic species assemblages. Sea surface temperature (SST) proxies are primarily derived from phytoplankton resulting in a seasonal bias toward spring/summer SST. Furthermore, SST proxies can be influenced by additional confounding variables (e.g. salinity, nutrients, depth habitat of biota) resulting in markedly different Holocene temperature reconstructions between proxy datasets. To evaluate the similarities and discrepancies between various marine proxies, we investigate a high-resolution sediment core collected from the central North Iceland Shelf (B997-316GGC, 658 m depth). Sedimentation covers the last millennium, which captures the transition from the Medieval Warm Period to the Little Ice Age. Age control is constrained by 14C dates and paleomagnetic secular variation. To assess marine surface productivity and sea ice conditions, we analyze quartz and calcite wt% via XRD and a series of highly branched isoprenoid biomarkers. Quantitative paleotemperature estimates are derived from a novel combination of Mg/Ca of foraminifera and two lipid biomarker indices, Uk'37 from Prymnesiophyte alkenones and TEX86 from Thaumarchaeota glycerol dialkyl glycerol tetraethers (GDGTs). The latter TEX86 record is the first paleo application in Icelandic waters, which a recent local calibration study suggests may reflect annual or winter sub-surface (0-200 m) temperatures. Our paleotemperature records are bolstered by the analysis of additional sediment core tops, which expand the established Icelandic calibrations. Finally, we perform statistical analyses in an effort to extract a robust record of paleoceanographic change and to test the applicability of various proxies in high-latitude paleoclimate studies.
NASA Astrophysics Data System (ADS)
Smith, K. A.; Hannaford, J.; Bloomfield, J.; McCarthy, M.; Parry, S.; Barker, L. J.; Svensson, C.; Tanguy, M.; Marchant, B.; McKenzie, A.; Legg, T.; Prudhomme, C.
2017-12-01
While the UK is regarded as a wet country, it has periodically suffered from major droughts which have caused serious environmental and societal impacts. Parts of the UK are water stressed and, in a warming world, changes to supply/demand balances could have major implications. There is a pressing need for improved tools for drought risk assessment, which is contingent on a proper understanding of past occurrence of droughts. However, our understanding of hydrological drought occurrence is grounded in the post-1960 period when most UK river flow and groundwater records commenced. As such, water resources planners would benefit from a more thorough assessment of historical drought characteristics and their variability. The multi-disciplinary `Historic Droughts' project thus aims to rigorously characterise droughts in the UK back to the 1890s to inform improved drought management. The foundation of this is a comprehensive characterisation of the hydroclimatology of UK droughts. Here, we present the results of this initiative, based on a hydrological reconstruction campaign of unparalleled scope and detail. Driven by rainfall and potential evapotranspiration data, extended in time using newly recovered observational records, hydro(geo)logical models are used to reconstruct, back to 1890, river flows for >300 catchments across the UK, and groundwater levels from >50 boreholes. The reconstructions are derived within a state-of-the-art modelling framework which allows a comprehensive assessment of uncertainty. A suite of indicators are then applied to these datasets to identify and characterise drought events, integrating precipitation, evapotranspiration, streamflow and groundwater. The work provides new insights into the spatial and temporal dynamics of hitherto poorly quantified late 19th and early 20th century droughts. Similarly, the assessment of temporal variability of drought characteristics benefits from the long timescale of the reconstructions, in turn allowing improved assessment of the large-scale climate drivers of UK droughts. The propagation of UK drought is analysed comprehensively for the first time, highlighting the differential spatio-temporal expression of meteorological, streamflow and groundwater droughts, with important implications for water resources management.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cundy, A.B.; Croudace, I.W.; Warwick, P.E.
1999-09-01
Radioactive discharges from nuclear facilities are frequently made into the marine environment and their fate during and after cessation of discharges is a matter of interest and concern. This study examines the decline of the radionuclides {sup 60} and {sup 65}Zn along the southern UK. coast, over the per 1988--1998, following the closure of the steam-generating heavy water (SGHW) reactor at AEA Winfrith, Dorset, UK. {sup 60}Co and {sup 65}Zn (and other activation products such as {sup 63}Ni and {sup 55}Fe) were widely dispersed in the marine environment off the central south coast of England, due to authorized releases frommore » AEA Winfrith. Significant interaction occurred with clay-rich sediments and biota. A general exponential decline in {sup 60}Co activities (and in {sup 65}Zn activity) is found in intertidal mudflat sediments, seaweed and marine fauna in different areas along the south coast following closure of the reactor in 1990. Effective half-lives are determined which vary from 1 to 4 years in surface sediments ({sup 60}Co only), 1--4 years in seaweed and 0.5--2.5 years in crustaceans, bivalves and molluscs. Physical mixing and bioturbation largely control the rate at which {sup 60}Co declines in surface sediments. Both {sup 60}Co and {sup 65}Zn show a relatively slow rate of decline in seaweed and in marine fauna, showing that even after the virtual cessation of discharge from nuclear facilities, contamination of these organisms may persist for a number of years, albeit at reduced activities. Reasons for this persistence are likely to include absorption of radionuclides from sediment, and release and recycling of radionuclides via breakdown of contaminated organic material.« less
Alfimov, V; Aldahan, A; Possnert, G; Winsor, P
2004-12-01
Variation in the concentrations of iodine-129 (129I, T1/2=15.7 Myr), a low-level radioactive component of nuclear fuel waste, is documented in surface waters and depth profiles collected during 2001 along a transect from the Norwegian Coastal Current to the North Pole. The surface waters near the Norwegian coast are found to have 20 times higher 129I concentration than the surface waters of the Arctic Ocean. The depth profiles of 129I taken in the Arctic Ocean reveal a sharp decline in the concentration to a depth of about 300-500 m followed by a weaker gradient extending down to the bottom. A twofold increase in the 129I concentration is observed in the upper 1000 m since 1996. Based on known estimates of marine transient time from the release sources (the nuclear reprocessing facilities at La Hague, France, and Sellafield, UK), a doubling in the 129I inventory of the top 1000 m of the Arctic Ocean is expected to occur between the years 2001 and 2006. As 129I of polar mixed layer and Atlantic layer of the Arctic Ocean is ventilated by the East Greenland Current into the Nordic Seas and North Atlantic Ocean, further dispersal and increase of the isotope concentration in these regions will be encountered in the near future.
The UKC2 regional coupled prediction system
NASA Astrophysics Data System (ADS)
Castillo, Juan; Lewis, Huw; Graham, Jennifer; Saulter, Andrew; Arnold, Alex; Fallmann, Joachim; Martinez de la Torre, Alberto; Blyth, Eleanor; Bricheno, Lucy
2017-04-01
It is hypothesized that more accurate prediction and warning of natural hazards, such as of the impacts of severe weather through the environment, requires a more integrated approach to forecasting. This approach also delivers research benefits through providing tools with which to explore the known interactions and feedbacks between different physical and biogeochemical components of the environment across sky, sea and land. This hypothesis is being tested in a UK regional context at km-scale through the UK Environmental Prediction Project. This presentation will provide an introduction to the UKC2 UK Environmental Prediction research system. This incorporates models of the atmosphere (Met Office Unified Model), land surface (JULES), shelf-sea ocean (NEMO) and ocean waves (WAVEWATCH III). These components are coupled (via OASIS3-MCT libraries) at unprecedentedly high resolution across the UK and the wider north-west European regional domain. A research framework has been established to explore the representation of feedback processes in coupled and uncoupled modes, providing a unique new research tool for UK environmental science. The presentation will highlight work undertaken to review and improve the computational cost of running these systems for efficient research application. Research will be presented highlighting case study evaluation on the sensitivity of the ocean and surface waves to the representation of feedbacks to the atmosphere, and on the sensitivity of weather systems and boundary layer cloud development to the exchange of heat and momentum at the ocean surface modified through sea surface temperature and wave-induced roughness. The presentation will discuss plans for future development through UKC3 and beyond.
NASA Astrophysics Data System (ADS)
Clancy, Sarah; Worrall, Fred; Davies, Richard; Gluyas, Jon
2017-04-01
The rapid growth of shale gas developments within the United States and the possibility of developments within Europe have raised concerns about the impact and potential environmental cost. In this study we estimated the likely physical footprint of well pads if shale gas or oil developments were to go forward in Europe and used these estimates to understand the impact upon existing infrastructure; the carrying capacity of the environment and how this may limit the proportion of resources that are accessible estimates. Conventional well pads in UK, The Netherlands and Poland were examined. For the existing UK conventional well pads the current minimum setback from a building for a currently producing well was measured. To assess the carrying capacity of the land surface, well pads, of the average well pad footprint, with recommended setbacks, were randomly placed into the licensed blocks covering the Bowland Shale, UK, and the extent to which they would interact or disrupt existing infrastructure assessed. The average conventional well site footprints were: 10800 m2 (1.08 ha) in the UK; 44600 m2 (4.46 ha) in The Netherlands; and 3000 m2 (0.30 ha) in Poland. The average area per well was: 541 m^2/well (0.05 ha/well) for the UK; 2870 m^2/well (0.29 ha/well) for Poland; and 6370 m^2/well (0.64 ha/well) for The Netherlands. Average access road lengths were: 230 m in the UK; 250 m in Poland; and 310 m in The Netherlands. The minimum setback from a building for a currently producing well was 21 m and 46 m from a house, though the mean setback was 329 and 447 m, respectively. When the surface and sub-surface footprints were considered our approach found that the carrying capacity of the sites and the restrictions from infrastructure over the currently licensed blocks covering the Bowland Shale (UK) was between 5 and 42%, with a mean of 26%. Using Cuadrilla's predicted recoverable reserves estimate of 8.5 x 10^11 m3 for the Bowland Basin, the carrying capacity of the surface and the likely maximum accessible gas reserves would be limited by the surface carrying capacity to 2.21 x 10^11 m^3.
The Case for the Development of a Theoretical Framework for Defence Acquisition
2014-04-30
the preliminary results of a pan-European working party of defence academics based in Sweden, Germany , and the UK. This group sought to surface the...preliminary results of a pan-European working party of defence academics based in Sweden, Germany , and the UK. This group sought to surface the...it involved a series of on-going discussions over a six month period between European academics and practitioners (drawn from France, Germany
NASA Astrophysics Data System (ADS)
Chen, Y.; Han, D.
2017-12-01
Water system is an essential component in a smart city for its sustainability and resilience. The freshness and beauty of the water body would please people as well as benefit the local aquatic ecosystems. Water quality monitoring approach has evolved from the manual lab-based monitoring approach to the manual in-situ monitoring approach, and finally to the latest wireless-sensor-network (WSN) based solutions in recent decades. The development of the in-situ water quality sensors enable humans to collect high-frequency and real-time water quality data. This poster aims to explore the advantages of the high-frequency water quality data over the low-frequency data collected manually. The data is collected by a remote real-time high-frequency water quality monitor system based on the cutting edge smart city infrastructure in Bristol - `Bristol Is Open'. The water quality of Bristol Floating Harbour is monitored which is the focal area of Bristol with new buildings and features redeveloped in the past decades. This poster will first briefly introduce the water quality monitoring system, followed by the analysis of the advantages of the sub-hourly water quality data. Thus, the suggestion on the monitoring frequency will be given.
Molinos-Senante, María; Maziotis, Alexandros; Sala-Garrido, Ramon
2015-11-01
The assessment of relative efficiency of water companies is essential for managers and authorities. This is evident in the UK water sector where there are companies with different services such as water and sewerage companies (WaSCs) and water-only companies (WoCs). Therefore, it is a critical limitation to estimate a common production frontier for both types of companies, as it might lead to biased efficiency estimates. In this paper, a robust and reliable methodology, the metafrontier model, is applied to compare the efficiency of water companies providing different services. The results illustrate the superior performance of WaSCs compared to WoCs. It also confirms the presence of economies of scope in the UK water industry. The methodology and results of this study are of great interest for both regulators and water utility managers to make informed decisions.
Illicit drugs and the environment--a review.
Pal, Raktim; Megharaj, Mallavarapu; Kirkbride, K Paul; Naidu, Ravi
2013-10-01
Illicit drugs and their metabolites are the latest group of emerging pollutants. Determination of their concentration in environment (such as water bodies, soil, sediment, air) is an indirect tool to estimate the community level consumption of illicit drug and to evaluate potential ecotoxicological impacts from chronic low level exposure. They enter the wastewater network as unaltered drugs and/or their active metabolites by human excretion after illegal consumption or by accidental or deliberate disposal from clandestine drug laboratories. This article critically reviews the occurrence and concentration levels of illicit drugs and their metabolites in different environmental compartments (e.g., wastewater, surface waters, groundwater, drinking water, and ambient air) and their potential impact on the ecosystem. There is limited published information available on the presence of illicit drugs in the environment, reports are available mainly from European countries, UK, USA, and Canada but there is a lack of information from the remainder of the world. Although the environmental concentrations are not very high, they can potentially impact the human health and ecosystem functioning. Cocaine, morphine, amphetamine, and MDMA have potent pharmacological activities and their presence as complex mixtures in water may cause adverse effect on aquatic organisms and human health. However, there is no current regulation demanding the determination of occurrence of these emerging pollutants in treated wastewater, surface water, drinking water, or atmosphere. Thus, critical investigation on distribution pattern of this new group of emerging contaminant and their potential harmful impact on our environment needs immediate attention. Copyright © 2012. Published by Elsevier B.V.
Crick, Florence; Jenkins, Katie; Surminski, Swenja
2018-04-25
Multisectoral partnerships are increasingly cited as a mechanism to deliver and improve disaster risk management. Yet, partnerships are not a panacea and more research is required to understand the role that they can play in disaster risk management and particularly disaster risk reduction. This paper investigates how partnerships can incentivise flood risk reduction by focusing on the UK public-private partnership on flood insurance. Developing the right flood insurance arrangements to incentivise flood risk reduction and adaptation to climate change is a key challenge. In the face of rising flood risks due to climate change and socio-economic development insurance partnerships can no longer afford to focus only on the risk transfer function. However, while expectations of the insurance industry have traditionally been high when it comes to flood risk management, the insurance industry alone will not provide the solution to the challenge of rising risks. The case of flood insurance in the UK illustrates this: even national government and industry together cannot fully address these risks and other actors need to be involved to create strong incentives for risk reduction. Using an agent-based model focused on surface water flood risk in London we analyse how other partners could strengthen the insurance partnership by reducing flood risk and thus helping to maintain affordable insurance premiums. Our findings are relevant for wider discussions on the potential of insurance schemes to incentivise flood risk management and climate adaptation in the UK and also internationally. Copyright © 2018. Published by Elsevier B.V.
NASA Astrophysics Data System (ADS)
Smith, Philip; England, Richard; Zalasiewicz, Jan
2017-04-01
Historical long wavelength uplift and subsidence patterns in the UK have been assumed to reflect glacial isostatic adjustment. Shorter wavelength variations are generally neglected, and do not fit with glacial rebound models, hence they may give important clues to other processes driving vertical motions. Present day vertical surface motions are based on one generation of observed data and do not necessarily represent the long-term stress and tectonic configuration of the UK. Cenozoic strata can provide a record of long-term changes and potentially can indicate the drivers of present day short wavelength variations. Understanding the dominant controls on UK tectonics may have implications for petroleum systems, geotechnical assessments and anthropogenic impact factors. Here we apply stratigraphic backstripping techniques to determine Cenozoic vertical surface motions. To complete the dataset, we also backstripped the Pleistocene Crag formations of East Anglia which post-dated the substantial Miocene hiatus most likely caused by the main phase of Alpine orogenic development. These deposits, the youngest being 2.1 Ma pre-date the glacial maximum of the UK helping to bridge the gap between the early Cenozoic and recent events. Subsidence analysis of the sequence indicates larger subsidence rates and sediment accumulation in the Hampshire basin than in the rest of southeast England. Reactivation of Variscan faults during the deposition of Cenozoic sediments appears to have taken place concomitantly with tectonic shortening and suggests phases of compression affected the UK throughout the Paleogene and Neogene not dissimilar to the current stress state and earthquake record. From our data we may be able to understand the major tectonic controls influencing southern England during the Cenozoic and assess the nature of the transition to the vertical surface motion observed from CGPS (Continuous Global Positioning Stations) at the present day. The Cenozoic could be a good analogue for the present day and for projecting into the future.
Nnane, Daniel Ekane
2011-11-15
Contamination of surface waters is a pervasive threat to human health, hence, the need to better understand the sources and spatio-temporal variations of contaminants within river catchments. River catchment managers are required to sustainably monitor and manage the quality of surface waters. Catchment managers therefore need cost-effective low-cost long-term sustainable water quality monitoring and management designs to proactively protect public health and aquatic ecosystems. Multivariate and phage-lysis techniques were used to investigate spatio-temporal variations of water quality, main polluting chemophysical and microbial parameters, faecal micro-organisms sources, and to establish 'sentry' sampling sites in the Ouse River catchment, southeast England, UK. 350 river water samples were analysed for fourteen chemophysical and microbial water quality parameters in conjunction with the novel human-specific phages of Bacteroides GB-124 (Bacteroides GB-124). Annual, autumn, spring, summer, and winter principal components (PCs) explained approximately 54%, 75%, 62%, 48%, and 60%, respectively, of the total variance present in the datasets. Significant loadings of Escherichia coli, intestinal enterococci, turbidity, and human-specific Bacteroides GB-124 were observed in all datasets. Cluster analysis successfully grouped sampling sites into five clusters. Importantly, multivariate and phage-lysis techniques were useful in determining the sources and spatial extent of water contamination in the catchment. Though human faecal contamination was significant during dry periods, the main source of contamination was non-human. Bacteroides GB-124 could potentially be used for catchment routine microbial water quality monitoring. For a cost-effective low-cost long-term sustainable water quality monitoring design, E. coli or intestinal enterococci, turbidity, and Bacteroides GB-124 should be monitored all-year round in this river catchment. Copyright © 2011 Elsevier B.V. All rights reserved.
The solsticial pause on Mars: 2 modelling and investigation of causes
NASA Astrophysics Data System (ADS)
Mulholland, David P.; Lewis, Stephen R.; Read, Peter L.; Madeleine, Jean-Baptiste; Forget, Francois
2016-01-01
The martian solsticial pause, presented in a companion paper (Lewis et al., 2016), was investigated further through a series of model runs using the UK version of the LMD/UK Mars Global Climate Model. It was found that the pause could not be adequately reproduced if radiatively active water ice clouds were omitted from the model. When clouds were used, along with a realistic time-dependent dust opacity distribution, a substantial minimum in near-surface transient eddy activity formed around solstice in both hemispheres. The net effect of the clouds in the model is, by altering the thermal structure of the atmosphere, to decrease the vertical shear of the westerly jet near the surface around solstice, and thus reduce baroclinic growth rates. A similar effect was seen under conditions of large dust loading, implying that northern midlatitude eddy activity will tend to become suppressed after a period of intense flushing storm formation around the northern cap edge. Suppression of baroclinic eddy generation by the barotropic component of the flow and via diabatic eddy dissipation were also investigated as possible mechanisms leading to the formation of the solsticial pause but were found not to make major contributions. Zonal variations in topography were found to be important, as their presence results in weakened transient eddies around winter solstice in both hemispheres, through modification of the near-surface flow. The zonal topographic asymmetry appears to be the primary reason for the weakness of eddy activity in the southern hemisphere relative to the northern hemisphere, and the ultimate cause of the solsticial pause in both hemispheres. The meridional topographic gradient was found to exert a much weaker influence on near-surface transient eddies.
NASA Astrophysics Data System (ADS)
Russell, Fiona; Chiverrell, Richard; Boyle, John
2016-04-01
Monitoring programmes have shown increases in concentrations of dissolved organic matter (DOM) in the surface waters of northern and central Europe (Monteith et al. 2007), and negative impacts of the browning of river waters have been reported for fish populations (Jonsson et al. 2012; Ranaker et al. 2012) and for ecosystem services such as water treatment (Tuvendal and Elmqvist 2011). Still the exact causes of the recent browning remain uncertain, the main contenders being climate change (Evans et al. 2005) and reduced ionic strength in surface water resulting from declines in anthropogenic sulphur and sea salt deposition (Monteith et al. 2007). There is a need to better understand the pattern, drivers and trajectory of these increases in DOC and POC in both recent and longer-term (Holocene) contexts to improve the understanding of carbon cycling within lakes and their catchments. In Britain there are some ideal sites for testing whether these trends are preserved and developing methods for reconstructing organic fluxes from lake sedimentary archives. There is a suite of lakes distributed across the country, the UK Acid Waters Monitoring Network (UKAWMN) sites, which have been monitored monthly for dissolved organic carbon and other aqueous species since 1988. These 12 lakes have well studied recent and in some case whole Holocene sediment records. Here four of those lakes (Grannoch, Chon, Scoat Tarn and Cwm Mynach) are revisited, with sampling focused on the sediment-water interface and very recent sediments (approx.150 years). At Scoat Tarn (approx. 1000 years) and Llyn Mynach (11.5k years) longer records have been obtained to assess equivalent patterns through the Holocene. Analyses of the gravity cores have focused on measuring and characterising the organic content for comparison with recorded surface water DOC measurements (UKAWMN). Data from pyrolysis measurements (TGA/DSC) in an N atmosphere show that the mass loss between 330-415°C correlates well with observed trends in DOC of surface waters. Analysis of these cores and various calibration materials (e.g. peat) suggests plant tissue undergoes pyrolysis at lower temperatures, and though humic substances can be generated in the lake this thermal phase may be a proxy record for catchment derived DOC. NIR and FTIR spectrometry data further characterise this organic phase, identify spectral structures that also correlate with monitored DOC. Together the pyrolysis, NIR, FTIR and XRF geochemistry (e.g. Fe/Mn, Si/Al ratios) data show also information on lake productivity, biogenic silica and mass accumulation rates. To explore the longer timescale equivalent proxy records have been trialled at Llyn Cwm Mynach and show possible phases of elevated DOC fluxes from catchment soils during the Holocene. References Evans C.D., Monteith D.T. and Cooper D.M. 2005. Long-term increases in surface water dissolved organic carbon: Observations, possible causes and environmental impacts. Environ. Pollut. 137: 55-71. Jonsson M., Ranaker L., Nilsson P.A. and Bronmark C. 2012. Prey-type-dependent foraging of young-of-the-year fish in turbid and humic environments. Ecol. Freshw. Fish 21: 461-468. Monteith D.T., Stoddard J.L., Evans C.D., de Wit H.A., Forsius M., Hogasen T., Wilander A., Skjelkvale B.L., Jeffries D.S., Vuorenmaa J., Keller B., Kopacek J. and Vesely J. 2007. Dissolved organic carbon trends resulting from changes in atmospheric deposition chemistry. Nature 450: 537-U539. Ranaker L., Jonsson M., Nilsson P.A. and Bronmark C. 2012. Effects of brown and turbid water on piscivore-prey fish interactions along a visibility gradient. Freshwater Biol. 57: 1761-1768. Tuvendal M. and Elmqvist T. 2011. Ecosystem Services Linking Social and Ecological Systems: River Brownification and the Response of Downstream Stakeholders. Ecol. Soc. 16
Simulation of infiltration and redistribution of intense rainfall using Land Surface Models
NASA Astrophysics Data System (ADS)
Mueller, Anna; Verhoef, Anne; Cloke, Hannah
2016-04-01
Flooding from intense rainfall (FFIR) can cause widespread damage and disruption. Numerical Weather Prediction (NWP) models provide distributed information about atmospheric conditions, such as precipitation, that can lead to a flooding event. Short duration, high intensity rainfall events are generally poorly predicted by NWP models, because of the high spatiotemporal resolution required and because of the way the convective rainfall is described in the model. The resolution of NWP models is ever increasing. Better understanding of complex hydrological processes and the effect of scale is important in order to improve the prediction of magnitude and duration of such events, in the context of disaster management. Working as part of the NERC SINATRA project, we evaluated how the Land Surface Model (LSM) components of NWP models cope with high intensity rainfall input and subsequent infiltration problems. Both in terms of the amount of water infiltrated in the soil store, as well as the timing and the amount of surface and subsurface runoff generated. The models investigated are SWAP (Soil Water Air Plant, Alterra, the Netherlands, van Dam 1997), JULES (Joint UK Land Environment Simulator a component of Unified Model in UK Met Office, Best et al. 2011) and CHTESSEL (Carbon and Hydrology- Tiled ECMWF Scheme for Surface Exchanges over Land, Balsamo et al. 2009) We analysed the numerical aspects arising from discontinuities (or sharp gradients) in forcing and/or the model solution. These types of infiltration configurations were tested in the laboratory (Vachaud 1971), for some there are semi-analytical solutions (Philip 1957, Parlange 1972, Vanderborght 2005) or reference numerical solutions (Haverkamp 1977, van Dam 2000, Vanderborght 2005). The maximum infiltration by the surface, Imax, is in general dependent on atmospheric conditions, surface type, soil type, soil moisture content θ, and surface orographic factor σ. The models used differ in their approach to describe and deal with this top boundary condition definition. All three LSMs discretise the spatial derivative in the Richards equation (∂/∂z) using central finite differences, which is a 2nd order method, that according to Godunov's theorem is non-monotone. It is prone to producing non-physical oscillations in the solution. We performed a mesh and timestep dependence study for hypothetical soil columns and showed the presence of the oscillations in Jules and SWAP solutions. We also investigated the rainfall/runoff partition and redistribution in case of intense rainfall using these three models.
NASA Astrophysics Data System (ADS)
Miller, J. D.; Rickards, N. J.; Kjeldsen, T. R.; Hutchins, M.; Rowland, C.; Prudhomme, C.; Maliko, T.; Fidal, J.; Hagen-Zanker, A.
2016-12-01
The UK population is set to increase by 16% by 2035; it is therefore increasingly important to understand the impact this may have on urban populations, and in turn how this will affect river flow regimes and water quality in urban areas. A growing population is likely to lead to an increase in urban land use and impervious surfaces, the implications of which are not yet fully understood for issues such as future flood risk. The aim of this paper is to develop a greater understanding of the impacts of both an increasing population and urban extent in the context of a changing climate, and to assess the effect these may have on urban streamflow regimes and water security in the future. Flows are modelled for selected catchments in the Thames basin using URBMOD, a lumped rainfall runoff model that is able to represent both pervious and impervious surfaces, reducing infiltration in catchments where there is a greater urban extent. The model uses daily catchment average rainfall and evapotranspiration derived from gridded data, and is calibrated against long-term river flow records. Historic satellite imagery is used to train cellular automata land use models, which are then applied under different scenarios of urban development up to 2035. These changes in land use are combined with a range of climate change scenarios to give an indication of how urban flow regimes may be altered in the Thames basin over the next 20 years. Results suggest an intensification of the hydrological regime in the majority of catchments, with increases in high flow magnitudes (Q10) of up to 5%. The trend for low flows (Q90) is less clear, with some catchments displaying reductions of around 4%, whilst others show slight increased flows. We identify the main drivers behind these changes, from which the fine-scale impacts of urbanisation on water resources can be better understood. Research findings are being used to inform a regional-scale model, coupling water quantity and quality and providing insight to urban planners and stakeholders on the future urban hydrological regime in the Thames basin. Similar approaches are being used to assess impacts of anthropogenic drivers on water resources in the Cauvery basin in India, whereby the applicability of the model under very different climate and urban morphology will be tested.
Satellite monitoring of sea surface pollution. [North and Irish Seas
NASA Technical Reports Server (NTRS)
Fielder, G.; Hall, T. S. (Principal Investigator); Telfer, D. J.; Wilson, L.; Fryer, R. J.
1980-01-01
Thermal IR data from NASA's Heat Capacity Mapping Mission were used in a study of the feasibility of detecting oil spills in the seas around the UK. The period of observation covered the years 1978/9, in which there were no major spills in the area. A video processor capable of generating false color renderings of any satellite image from eight density levels was used in the synoptic search for spills. Other laboratory equipment, and associated analyses, were used to study the thermal behavior of oil spills on water. Oil spills may appear to be warmer or cooler that the surrounding sea, depending on numerous factors.
Catchment scale water resource constraints on UK policies for low-carbon energy system transition
NASA Astrophysics Data System (ADS)
Konadu, D. D.; Fenner, R. A.
2017-12-01
Long-term low-carbon energy transition policy of the UK presents national scale propositions of different low-carbon energy system options that lead to meeting GHG emissions reduction target of 80% on 1990 levels by 2050. Whilst national-scale assessments suggests that water availability may not be a significant constrain on future thermal power generation systems in this pursuit, these analysis fail to capture the appropriate spatial scale where water resource decisions are made, i.e. at the catchment scale. Water is a local resource, which also has significant spatio-temporal regional and national variability, thus any policy-relevant water-energy nexus analysis must be reflective of these characteristics. This presents a critical challenge for policy relevant water-energy nexus analysis. This study seeks to overcome the above challenge by using a linear spatial-downscaling model to allocate nationally projected water-intensive energy system infrastructure/technologies to the catchment level, and estimating the water requirements for the deployment of these technologies. The model is applied to the UK Committee on Climate Change Carbon Budgets to 2030 as a case study. The paper concludes that whilst national-scale analyses show minimal long-term water related impacts, catchment level appraisal of water resource requirements reveal significant constraints in some locations. The approach and results presented in this study thus, highlights the importance of bringing together scientific understanding, data and analysis tools to provide better insights for water-energy nexus decisions at the appropriate spatial scale. This is particularly important for water stressed regions where the water-energy nexus must be analysed at appropriate spatial resolution to capture the full water resource impact of national energy policy.
Constructed wetlands in UK urban surface drainage systems.
Shutes, B; Ellis, J B; Revitt, D M; Scholes, L N L
2005-01-01
This paper presents the outcome of an inventory of planted wetland systems in the UK which are classified according to land use type and are all examples of sustainable drainage systems. The introduction of constructed wetlands to treat surface runoff essentially followed a 1997 Environment Agency for England and Wales report advocating the use of "soft engineered" facilities including wetlands in the context of sustainable development and Agenda 21. Subsequently published reports by the UK Construction Industry Research and Information Association (CIRIA) have promoted the potential benefits to both developer and the community of adopting constructed wetlands and other vegetated systems as a sustainable drainage approach. In addition, the UK Environment Agency and Highways Agency (HA) have recently published their own design criteria and requirements for vegetative control and treatment of road runoff. A case study of the design and performance of a constructed wetland system for the treatment of road runoff is discussed. The performance of these systems will be assessed in terms of their design criteria, runoff loadings as well as vegetation and structure maintenance procedures. The differing design approaches in guidance documents published in the UK by the Environment Agency, CIRIA and HA will also be evaluated.
Pliocene Warm Period Upwelling in the Southern Benguela Region
NASA Astrophysics Data System (ADS)
Petrick, B. F.; McClymont, E.; Felder, S.; Leng, M. J.; Rosell Mele, A.; Rueda, G.
2014-12-01
The mid-Pliocene has been proposed as a possible analogue for understanding future climate change and testing climate models. Previous work has shown that during the Pliocene the major upwelling systems were relatively warm, and thus either inactive, contracted, or upwelling warmer waters than present. Here we examine evidence from a core site located on the margins of the modern Benguela upwelling system, to test whether the upwelling cells had migrated or contracted relative to present during the Pliocene. We applied several organic geochemistry proxies and foraminiferal analyses to reconstruct the Pliocene history of ODP site 1087 (31º28'S, 15º19'E, 1374m water depth), including the UK37' index and TEX86 index (for reconstructing sea surface temperatures), chlorins (for estimating primary productivity) and planktonic foraminifera assemblages (for inferring water mass changes). These proxies show that between 3.5 and 3.0 Ma the southern Benguela region was significantly cooler than the northern Benguela region, the latter where the main upwelling cells are found today. Coupled with higher primary production, a shift in planktonic foraminifera assemblage, and an offset between the UK37' index and TEX86 index, we infer that more extensive upwelling was present in the southern Benguela region during the Pliocene. We infer that the main Benguela upwelling cells had shifted southward relative to today, as a result of changes in the local wind field. We find evidence for pronounced cooling and a shift in the planktonic foraminifera assemblage during the M2 and KM2 glacial stages, showing a sensitivity of Benguela upwelling to these short-lived climate events.
The fissured East Yorkshire Chalk, UK - a 'sustainable' aquifer under stress ?
NASA Astrophysics Data System (ADS)
Elliot, T.; Younger, P. L.; Chadha, D. S.
2003-04-01
The fissured Chalk is an important regional aquifer in East Yorkshire, UK, with a large potential for water supply to the Humberside region and especially the City of Hull. It has been exploited since the end of the 19th Century, but although there are more than a dozen long-established pumping wells in the Chalk these currently abstract only 7% of the total recharge the aquifer receives. The classical notion of ‘safe aquifer yield' equates the quantity of groundwater available for abstraction with the long-term natural recharge to the aquifer. An incautious hydrogeologist might be lead to conclude that this is a secure, under-developed resource. In this case study, the aquifer is shown to be already displaying early symptoms of hydrological stress (eg drought effects, overexploitation), and hydrogeochemical indicators point to further effects of anthropogenic pollution impacts in the unconfined aquifer and both recent and ancient saline intrusion in its semi-confined and confined zones. The hydrochemical evidence clearly reveals the importance both of recent aquifer management decisions and palaeohydrogeology in determining the distribution of water qualities within the aquifer. Waters encountered in the confined aquifer are identified as complex (and potentially dynamic) mixtures between recently recharged waters, modern seawater intrusion, and ancient seawater which entered the aquifer many millennia ago. Elliot, T. Younger, P.L. &Chadha, D.S. (1998) The future sustainability of groundwater resources in East Yorkshire - past and present perspectives. In H. Wheater and C. Kirby (Eds.) Hydrology in a Changing Environment, Vol. II, Proc. British Hydrological Society (BHS) International Conference, 6-10 July 1998, Exeter, UK. pp.21-31. Elliot, T., Chadha, D.S. &Younger, P.L. (2001) Water Quality Impacts and Palaeohydrogeology in the East Yorkshire Chalk Aquifer, UK. Quarterly Journal of Engineering Geology and Hydrogeology, 34(4): 385-398. Younger, P.L., Teutsch, G., Custodio, E., Elliot, T., Manzano, M. &Sauter, M. (2002) Assessments of the sensitivity to climate change of flow and natural water quality in four major carbonate aquifers of Europe. In Hiscock, K.M, Rivett, M.O., Davison, R.M. (Eds.), Sustainable Groundwater Development. Geological Society Special Publication No 193, The Geological Society, London, UK. pp.303-323.
Arsenic in garden soils and vegetable crops in Cornwall, England: Implications for human health.
Xu, J; Thornton, I
1985-12-01
Total concentrations of arsenic in surface (0-15cm) garden soils in the historical mining area of Hayle-Camborne-Godolphin, Cornwall, England are large and range widely (144-892 μg/g). Amounts of water soluble and acid-fluoride extractable soil arsenic are significantly correlated with total content.Examination of 6 salad and vegetable crops grown in 32 gardens has shown arsenic concentrations in the edible tissues to be only slightly elevated. There were strong correlations between arsenic in beetroot, lettuce, onion and peas and soil arsenic (total, water soluble and acid extractable). Regression equations have been calculated. Ridge regression analysis applied to test the importance of other soil variables has shown both iron and phosphorus to influence the uptake of arsenic.Arsenic in all the vegetables sampled was below the statutory limit in the U.K. of 1 mg/kg fresh weight. Implications for health should be assessed in relation to other exposure routesvia water, air and directly ingested dust and soil.
Batty, Lesley C; Younger, Paul L
2004-11-01
The abandoned mine of Shilbottle Colliery, Northumberland, UK is an example of acidic spoil heap discharge that contains elevated levels of many metals. Aerobic wetlands planted with the common reed, Phragmites australis, were constructed at the site to treat surface runoff from the spoil heap. The presence of a perched water table within the spoil heap resulted in the lower wetlands receiving acidic metal contaminated water from within the spoil heap while the upper wetland receives alkaline, uncontaminated surface runoff from the revegetated spoil. This unique situation enabled the comparison of metal uptake and growth of plants used in treatment schemes in two cognate wetlands. Results indicated a significant difference in plant growth between the two wetlands in terms of shoot height and seed production. Analyses of metal and nutrient concentrations within plant tissues provided the basis for three hypotheses to explain these differences: (i) the toxic effects of high levels of metals in shoot tissues, (ii) the inhibition of Ca (an essential nutrient) uptake by the presence of metals and H+ ions, and (iii) low concentrations of bioavailable nitrogen sources resulting in nitrogen deficiency. This has important implications for the engineering of constructed wetlands in terms of the potential success of plant establishment and vegetation development.
Hou, Deyi; Al-Tabbaa, Abir; Guthrie, Peter
2014-08-15
The sustainable remediation concept, aimed at maximizing the net environmental, social, and economic benefits in contaminated site remediation, is being increasingly recognized by industry, governments, and academia. However, there is limited understanding of actual sustainable behaviour being adopted and the determinants of such sustainable behaviour. The present study identified 27 sustainable practices in remediation. An online questionnaire survey was used to rank and compare them in the US (n=112) and the UK (n=54). The study also rated ten promoting factors, nine barriers, and 17 types of stakeholders' influences. Subsequently, factor analysis and general linear models were used to determine the effects of internal characteristics (i.e. country, organizational characteristics, professional role, personal experience and belief) and external forces (i.e. promoting factors, barriers, and stakeholder influences). It was found that US and UK practitioners adopted many sustainable practices to similar extents. Both US and UK practitioners perceived the most effectively adopted sustainable practices to be reducing the risk to site workers, protecting groundwater and surface water, and reducing the risk to the local community. Comparing the two countries, we found that the US adopted innovative in-situ remediation more effectively; while the UK adopted reuse, recycling, and minimizing material usage more effectively. As for the overall determinants of sustainable remediation, the country of origin was found not to be a significant determinant. Instead, organizational policy was found to be the most important internal characteristic. It had a significant positive effect on reducing distant environmental impact, sustainable resource usage, and reducing remediation cost and time (p<0.01). Customer competitive pressure was found to be the most extensively significant external force. In comparison, perceived stakeholder influence, especially that of primary stakeholders (site owner, regulator, and primary consultant), did not appear to have as extensive a correlation with the adoption of sustainability as one would expect. Copyright © 2014 Elsevier B.V. All rights reserved.
Spatio-temporal models to determine association between Campylobacter cases and environment
Sanderson, Roy A; Maas, James A; Blain, Alasdair P; Gorton, Russell; Ward, Jessica; O’Brien, Sarah J; Hunter, Paul R; Rushton, Stephen P
2018-01-01
Abstract Background Campylobacteriosis is a major cause of gastroenteritis in the UK, and although 70% of cases are associated with food sources, the remainder are probably associated with wider environmental exposure. Methods In order to investigate wider environmental transmission, we conducted a spatio-temporal analysis of the association of human cases of Campylobacter in the Tyne catchment with weather, climate, hydrology and land use. A hydrological model was used to predict surface-water flow in the Tyne catchment over 5 years. We analysed associations between population-adjusted Campylobacter case rate and environmental factors hypothesized to be important in disease using a two-stage modelling framework. First, we investigated associations between temporal variation in case rate in relation to surface-water flow, temperature, evapotranspiration and rainfall, using linear mixed-effects models. Second, we used the random effects for the first model to quantify how spatial variation in static landscape features of soil and land use impacted on the likely differences between subcatchment associations of case rate with the temporal variables. Results Population-adjusted Campylobacter case rates were associated with periods of high predicted surface-water flow, and during above average temperatures. Subcatchments with cattle on stagnogley soils, and to a lesser extent sheep plus cattle grazing, had higher Campylobacter case rates. Conclusions Areas of stagnogley soils with mixed livestock grazing may be more vulnerable to both Campylobacter spread and exposure during periods of high rainfall, with resultant increased risk of human cases of the disease. PMID:29069406
Computational modeling in the optimization of corrosion control to reduce lead in drinking water
An international “proof-of-concept” research project (UK, US, CA) will present its findings during this presentation. An established computational modeling system developed in the UK is being calibrated and validated in U.S. and Canadian case studies. It predicts LCR survey resul...
NASA Astrophysics Data System (ADS)
Quaife, T. L.; Davenport, I. J.; Lines, E.; Styles, J.; Lewis, P.; Gurney, R. J.
2012-12-01
Satellite observations offer a spatially and temporally synoptic data source for constraining models of land surface processes, but exploitation of these data for such purposes has been largely ad-hoc to date. In part this is because traditional land surface models, and hence most land surface data assimilation schemes, have tended to focus on a specific component of the land surface problem; typically either surface fluxes of water and energy or biogeochemical cycles such as carbon and nitrogen. Furthermore the assimilation of satellite data into such models tends to be restricted to a single wavelength domain, for example passive microwave, thermal or optical, depending on the problem at hand. The next generation of land surface schemes, such as the Joint UK Land Environment Simulator (JULES) and the US Community Land Model (CLM) represent a broader range of processes but at the expense of increasing overall model complexity and in some cases reducing the level of detail in specific processes to accommodate this. Typically, the level of physical detail used to represent the interaction of electromagnetic radiation with the surface is not sufficient to enable prediction of intrinsic satellite observations (reflectance, brightness temperature and so on) and consequently these are not assimilated directly into the models. A seemingly attractive alternative is to assimilate high-level products derived from satellite observations but these are often only superficially related to the corresponding variables in land surface models due to conflicting assumptions between the two. This poster describes the water and energy balance modeling components of a project funded by the European Space Agency to develop a data assimilation scheme for the land surface and observation operators to translate between models and the intrinsic observations acquired by satellite missions. The rationale behind the design of the underlying process model is to represent the physics of the water and energy balance in as parsimonious manner as possible, using a force-restore approach, but describing the physics of electromagnetic radiation scattering at the surface sufficiently well that it is possible to assimilate the intrinsic observations made by remote sensing instruments. In this manner the initial configuration of the resulting scheme will be able to make optimal use of available satellite observations at arbitrary wavelengths and geometries. Model complexity can then be built up from this point whilst ensuring consistency with satellite observations.
Current and future climate- and air pollution-mediated impacts on human health.
Doherty, Ruth M; Heal, Mathew R; Wilkinson, Paul; Pattenden, Sam; Vieno, Massimo; Armstrong, Ben; Atkinson, Richard; Chalabi, Zaid; Kovats, Sari; Milojevic, Ai; Stevenson, David S
2009-12-21
We describe a project to quantify the burden of heat and ozone on mortality in the UK, both for the present-day and under future emission scenarios. Mortality burdens attributable to heat and ozone exposure are estimated by combination of climate-chemistry modelling and epidemiological risk assessment. Weather forecasting models (WRF) are used to simulate the driving meteorology for the EMEP4UK chemistry transport model at 5 km by 5 km horizontal resolution across the UK; the coupled WRF-EMEP4UK model is used to simulate daily surface temperature and ozone concentrations for the years 2003, 2005 and 2006, and for future emission scenarios. The outputs of these models are combined with evidence on the ozone-mortality and heat-mortality relationships derived from epidemiological analyses (time series regressions) of daily mortality in 15 UK conurbations, 1993-2003, to quantify present-day health burdens. During the August 2003 heatwave period, elevated ozone concentrations > 200 microg m-3 were measured at sites in London and elsewhere. This and other ozone photochemical episodes cause breaches of the UK air quality objective for ozone. Simulations performed with WRF-EMEP4UK reproduce the August 2003 heatwave temperatures and ozone concentrations. There remains day-to-day variability in the high ozone concentrations during the heatwave period, which on some days may be explained by ozone import from the European continent.Preliminary calculations using extended time series of spatially-resolved WRF-EMEP4UK model output suggest that in the summers (May to September) of 2003, 2005 & 2006 over 6000 deaths were attributable to ozone and around 5000 to heat in England and Wales. The regional variation in these deaths appears greater for heat-related than for ozone-related burdens.Changes in UK health burdens due to a range of future emission scenarios will be quantified. These future emissions scenarios span a range of possible futures from assuming current air quality legislation is fully implemented, to a more optimistic case with maximum feasible reductions, through to a more pessimistic case with continued strong economic growth and minimal implementation of air quality legislation. Elevated surface ozone concentrations during the 2003 heatwave period led to exceedences of the current UK air quality objective standards. A coupled climate-chemistry model is able to reproduce these temperature and ozone extremes. By combining model simulations of surface temperature and ozone with ozone-heat-mortality relationships derived from an epidemiological regression model, we estimate present-day and future health burdens across the UK. Future air quality legislation may need to consider the risk of increases in future heatwaves.
Carbon accounting in the United Kingdom water sector: a review.
Prescott, C
2009-01-01
The UK is committed to greenhouse gas (GHG) emission reduction targets and has introduced a number of initiatives to achieve these. Until recently, these targeted energy-intensive industries and, thus, the water sector was not significantly affected. However, from 2010, UK water companies will need to report their emissions under the Carbon Reduction Commitment (CRC). Both Ofwat (the economic regulator for water companies in England and Wales) and the Northern Ireland Authority for Utility Regulation (NIAUR) now require annual reporting of GHG emissions in accordance with both Defra Guidelines and the CRC. Also, carbon impacts must now be factored into all water industry investment planning in England and Wales. Building on existing approaches, the industry has developed standardised carbon accounting methodologies to meet both of these requirements. This process has highlighted gaps in knowledge where further research is needed.
Lathouri, Maria; Korre, Anna
2015-12-15
Although significant progress has been made in understanding how environmental factors modify the speciation, bioavailability and toxicity of metals such as copper in aquatic environments, the current methods used to establish water quality standards do not necessarily consider the different geological and geochemical characteristics of a given site and the factors that affect copper fate, bioavailability potential and toxicity. In addition, the temporal variation in the concentration and bioavailable metal fraction is also important in freshwater systems. The work presented in this paper illustrates the temporal and seasonal variability of a range of water quality parameters, and Cu speciation, bioavailability and toxicity at four freshwaters sites in the UK. Rivers Coquet, Cree, Lower Clyde and Eden (Kent) were selected to cover a broad range of different geochemical environments and site characteristics. The monitoring data used covered a period of around six years at almost monthly intervals. Chemical equilibrium modelling was used to study temporal variations in Cu speciation and was combined with acute toxicity modelling to assess Cu bioavailability for two aquatic species, Daphnia magna and Daphnia pulex. The estimated copper bioavailability, toxicity levels and the corresponding ecosystem risks were analysed in relation to key water quality parameters (alkalinity, pH and DOC). Although copper concentrations did not vary much during the sampling period or between the seasons at the different sites; copper bioavailability varied markedly. In addition, through the chronic-Cu BLM-based on the voluntary risk assessment approach, the potential environmental risk in terms of the chronic toxicity was assessed. A much higher likelihood of toxicity effects was found during the cold period at all sites. It is suggested that besides the metal (copper) concentration in the surface water environment, the variability and seasonality of other important water quality parameters should be considered in setting appropriately protective environmental quality standards for metals. Copyright © 2015 Elsevier B.V. All rights reserved.
Fluorine in the UK environment.
Fuge, R; Andrews, M J
1988-12-01
Relatively low concentrations of fluorine in drinking water (≤ 1 mg F/l) have been shown to significantly reduce the degree of dental caries in children and fluorine would also appear to have a beneficial effect on bone formation in both humans and farm animals. However, it is apparent that elevated levels of fluorine in the diet have sometimes resulted in problems of increased dental caries and of the development of bone deformities. Much of the fluorine in rocks and soils occurs in apatite and hydroxysilicate minerals, fluorite being the only relatively common rock forming mineral containing fluorine as an essential constituent.Little systematic data are available on fluorine concentrations in soils, plants and natural waters in the UK. General background soil concentrations lie in the range 200 - 400 mg F/kg. For waters the average fluorine content is low, <0.1 mg F/l.In the British Isles there are several areas where there are enhanced levels of fluorine. In the northern Pennines, Derbyshire, northeast Wales and Cornwall, fluorite occurs as a significant component of mineralisation and much fluorine has been added to the environment from mining waste dumps. Soils in northeast Wales contain up to 3,650 mg F/kg and in the northern Pennines up to 20,000 mg F/kg. Waters contain up to 2.3 mg F/l. In southwest England, the granites are generally fluorine-rich with the fluorite granites of the St Austell pluton containing as much as 1 percent fluorine. These rocks are frequently kaolinised and intensively worked as a source of china clay. Soils in the vicinity of the waste tips contain up to 3,300 mg F/kg and grasses up to 2,950 mg F/kg. Surface waters in the St Austell area contain up to 1.25 mg F/l.Atmospheric fluorine pollution around brickworks in the Peterborough and Bedford areas has resulted in fluorosis in farm animals. Other sources of atmospheric fluorine pollution are aluminium smelters, steelworks and fossil fuel burning.
Testing the Joint UK Land Environment Simulator (JULES) for flood forecasting
NASA Astrophysics Data System (ADS)
Batelis, Stamatios-Christos; Rosolem, Rafael; Han, Dawei; Rahman, Mostaquimur
2017-04-01
Land Surface Models (LSM) are based on physics principles and simulate the exchanges of energy, water and biogeochemical cycles between the land surface and lower atmosphere. Such models are typically applied for climate studies or effects of land use changes but as the resolution of LSMs and supporting observations are continuously increasing, its representation of hydrological processes need to be addressed adequately. For example, changes in climate and land use can alter the hydrology of a region, for instance, by altering its flooding regime. LSMs can be a powerful tool because of their ability to spatially represent a region with much finer resolution. However, despite such advantages, its performance has not been extensively assessed for flood forecasting simply because its representation of typical hydrological processes, such as overland flow and river routing, are still either ignored or roughly represented. In this study, we initially test the Joint UK Land Environment Simulator (JULES) as a flood forecast tool focusing on its river routing scheme. In particular, JULES river routing parameterization is based on the Rapid Flow Model (RFM) which relies on six prescribed parameters (two surface and two subsurface wave celerities, and two return flow fractions). Although this routing scheme is simple, the prescription of its six default parameters is still too generalized. Our aim is to understand the importance of each RFM parameter in a series of JULES simulations at a number of catchments in the UK for the 2006-2015 period. This is carried out, for instance, by making a number of assumptions of parameter behaviour (e.g., spatially uniform versus varying and/or temporally constant or time-varying parameters within each catchment). Hourly rainfall radar in combination with the CHESS (Climate, Hydrological and Ecological research Support System) meteorological daily data both at 1 km2 resolution are used. The evaluation of the model is based on hourly runoff data provided by the National River Flood Archive using a number of model performance metrics. We use a calibrated conceptually-based lumped model, more typically applied in flood studies, as a benchmark for our analysis.
Clancy, S A; Worrall, F; Davies, R J; Gluyas, J G
2018-03-15
We estimate the likely physical footprint of well pads if shale gas or oil developments were to go forward in Europe and used these estimates to understand their impact upon existing infrastructure (e.g. roads, buildings), the carrying capacity of the environment, and how the proportion of extractable resources maybe limited. Using visual imagery, we calculate the average conventional well site footprints to be 10,800m 2 in the UK, 44,600m 2 in The Netherlands and 3000m 2 in Poland. The average area per well is 541m 2 /well in the UK, 6370m 2 /well in The Netherlands, and 2870m 2 /well in Poland. Average access road lengths are 230m in the UK, 310m in The Netherlands and 250m in Poland. To assess the carrying capacity of the land surface, well pads of the average footprint, with recommended setbacks, were placed randomly into the licensed blocks covering the Bowland Shale, UK. The extent to which they interacted or disrupted existing infrastructure was then assessed. For the UK, the direct footprint would have a 33% probability of interacting with immovable infrastructure, but this would rise to 73% if a 152m setback was used, and 91% for a 609m setback. The minimum setbacks from a currently producing well in the UK were calculated to be 21m and 46m from a non-residential and residential property respectively, with mean setbacks of 329m and 447m, respectively. When the surface and sub-surface footprints were considered, the carrying capacity within the licensed blocks was between 5 and 42%, with a mean of 26%. Using previously predicted technically recoverable reserves of 8.5×10 11 m 3 for the Bowland Basin and a recovery factor of 26%, the likely maximum accessible gas reserves would be limited by the surface carrying capacity to 2.21×10 11 m 3 . Copyright © 2017 Elsevier B.V. All rights reserved.
Water and beverage consumption patterns among 4 to 13-year-old children in the United Kingdom.
Vieux, Florent; Maillot, Matthieu; Constant, Florence; Drewnowski, Adam
2017-05-19
The UK government has announced a tax on sugar-sweetened beverages. The aim of this study was to assess consumption patterns for plain drinking water relative to sugary beverages among UK children. Dietary intake data for 845 children aged 4-13 years came from the nationally representative cross-sectional National Diet and Nutrition Survey, 2008-2011. Beverage categories were drinking water (tap or bottled), milk, 100% fruit juices, soda, fruit drinks, tea, coffee, sports drinks, flavored waters, and liquid supplements. Consumption patterns were examined by age group, gender, household incomes, time and location of consumption, region and seasonality. Total water consumption from drinking water, beverages, and foods, and the water-to-calorie ratios (L/kcal) were compared to the EFSA (European Food Safety Authority) adequate intake standards. Total water intake (1338 ml/d) came from plain water (19%), beverages (48%), and food moisture (33%). Plain drinking water provided 258 g/d (241 g/d for children aged 4-8 years; 274 g/d for 9-13 years), mostly (83.8%) from tap. Water and beverages supplied 901 g /d of water. Tap water consumption increased with income and was highest in the South of England. The consumption of bottled water, soda, tea and coffee increased with age, whereas milk consumption declined. About 88.7% of children did not meet EFSA adequate intake standards. The daily water shortfall ranged from 322 ml/d to 659 ml/d. Water-to-calorie ratio was 0.845 L/1000 kcal short of desirable levels of 1.0-1.5 L/1000 kcal. Total water intake were at 74.8% of EFSA reference values. Drinking water consumption among children in the UK was well below US and French estimates.
NASA Astrophysics Data System (ADS)
Swinscoe, T. H. A.; Knoeri, C.; Fleskens, L.; Barrett, J.
2014-12-01
Freshwater is a vital natural resource for multiple needs, such as drinking water for the public, industrial processes, hydropower for energy companies, and irrigation for agriculture. In the UK, crop production is the largest in East Anglia, while at the same time the region is also the driest, with average annual rainfall between 560 and 720 mm (1971 to 2000). Many water catchments of East Anglia are reported as over licensed or over abstracted. Therefore, freshwater available for agricultural irrigation abstraction in this region is becoming both increasingly scarce due to competing demands, and increasingly variable and uncertain due to climate and policy changes. It is vital for water users and policy makers to understand how these factors will affect individual abstractors and water resource management at the system level. We present first results of an Agent-based Model that captures the complexity of this system as individual abstractors interact, learn and adapt to these internal and external changes. The purpose of this model is to simulate what patterns of water resource management emerge on the system level based on local interactions, adaptations and behaviours, and what policies lead to a sustainable water resource management system. The model is based on an irrigation abstractor typology derived from a survey in the study area, to capture individual behavioural intentions under a range of water availability scenarios, in addition to farm attributes, and demographics. Regional climate change scenarios, current and new abstraction licence reforms by the UK regulator, such as water trading and water shares, and estimated demand increases from other sectors were used as additional input data. Findings from the integrated model provide new understanding of the patterns of water resource management likely to emerge at the system level.
The ESA SMOS+SOS Project: Oceanography using SMOS for innovative air-sea exchange studies
NASA Astrophysics Data System (ADS)
Banks, Chris; Gommenginger, Christine; Boutin, Jacqueline; Reul, Nicolas; Martin, Matthew; Ash, Ellis; Reverdin, Gilles; Donlon, Craig
2013-04-01
We report on the work plan of the SMOS+Surface Ocean Salinity and Synergy (SMOS+SOS) project. SMOS+SOS is funded through the Support to Science Element (STSE) component of the European Space Agency's (ESA) Earth Observation Envelope Programme. The SMOS+SOS consortium consists of four organisations namely the National Oceanography Centre (UK), the LOCEAN/IFREMER/CATDS research team (France), the Met Office (UK) and Satellite Oceanographic Consultants Ltd (UK). The end of the SMOS+SOS project will be marked by a final open workshop most likely hosted by the UK Met Office in September/October 2014. The project is concerned with demonstrating the performance and scientific value of SMOS Sea Surface Salinity (SSS) products through a number of well-defined case studies. The case studies include: Amazon/Orinoco plumes (freshwater outflow); Agulhas and Gulf Stream (strong water mass boundary); Tropical Pacific/Atlantic (strong precipitation regime); sub-tropical North Atlantic (ie SPURS; strong evaporative regime); and Equatorial Pacific (equatorial upwelling). With SMOS measuring the SSS in the top cm of the ocean, validating SMOS against in situ salinity data taken typically at a few meters depth introduces assumptions about the vertical structure of salinity in the upper ocean. To address these issues, the project will examine and quantify discrepancies between SMOS and in situ surface salinity data at various depths in different regions characterised by strong precipitation or evaporation regimes. Equally, data editing and spatio-temporal averaging play a central role in determining the quality, errors and correlations in SMOS SSS data. The project will explore various processing and spatio-temporal averaging choices to define the SMOS SSS products that best address the needs of the oceanographic and data assimilation user community. One key aspect of this project is to determine how one can achieve useful accuracy/uncertainty in SSS without jeopardising SMOS's ability to capture rapidly-varying or small scale features such as rain cells or the mesoscale variability associated with river plumes and major western boundary currents. Finally, the study explores the ability of SMOS SSS to provide insights into new oceanographic processes when used in synergy with other data. Hence, synergy with Aquarius will be used to seek evidence of the possible impact of diurnal warming on the SMOS SSS data, and to explore differences in the salinity signatures of Tropical Instability Waves observed in the Pacific with SMOS and Aquarius.
Trajectories of water table recovery following the re-vegetation of bare peat
NASA Astrophysics Data System (ADS)
Shuttleworth, Emma; Evans, Martin; Allott, Tim; Maskill, Rachael; Pilkington, Michael; Walker, Jonathan
2016-04-01
The hydrological status of blanket peat influences a wide range of peatland functions, such as runoff generation, water quality, vegetation distribution, and rates of carbon sequestration. The UK supports 15% of the world's blanket peat cover, but much of this vital resource is significantly degraded, impacted by industrial pollution, overgrazing, wildfire, and climatic shifts. These pressures have produced a unique landscape characterised by severe gully erosion and extensive areas of bare peat. This in turn has led water tables to become substantially drawn down, impacting peatland function and limiting the resilience of these landscapes to future changes in climate. The restoration of eroding UK peatlands is a major conservation concern, and landscape-scale interventions through the re-vegetation of bare peat is becoming increasingly extensive in areas of upland Britain. Water table is the primary physical parameter considered in the monitoring of many peatland restoration projects, and there is a wealth of data on individual monitoring programmes which indicates that re-vegetation significantly raises water tables. This paper draws on data from multiple restoration projects carried out by the Moors for the Future Partnership in the Southern Pennines, UK, covering a range of stages in the erosion-restoration continuum, to assess the trajectories of water table recovery following re-vegetation. This will allow us to generate projections of future water table recovery, which will be of benefit to land managers and conservation organisations to inform future restoration initiatives.
On the detection and attribution of gravity waves generated by the 20 March 2015 solar eclipse
2016-01-01
Internal gravity waves are generated as adjustment radiation whenever a sudden change in forcing causes the atmosphere to depart from its large-scale balanced state. Such a forcing anomaly occurs during a solar eclipse, when the Moon’s shadow cools part of the Earth’s surface. The resulting atmospheric gravity waves are associated with pressure and temperature perturbations, which in principle are detectable both at the surface and aloft. In this study, surface pressure and temperature data from two UK sites at Reading and Lerwick are examined for eclipse-driven gravity wave perturbations during the 20 March 2015 solar eclipse over northwest Europe. Radiosonde wind data from the same two sites are also analysed using a moving parcel analysis method, to determine the periodicities of the waves aloft. On this occasion, the perturbations both at the surface and aloft are found not to be confidently attributable to eclipse-driven gravity waves. We conclude that the complex synoptic weather conditions over the UK at the time of this particular eclipse helped to mask any eclipse-driven gravity waves. This article is part of the themed issue ‘Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse’. PMID:27550763
On the detection and attribution of gravity waves generated by the 20 March 2015 solar eclipse.
Marlton, G J; Williams, P D; Nicoll, K A
2016-09-28
Internal gravity waves are generated as adjustment radiation whenever a sudden change in forcing causes the atmosphere to depart from its large-scale balanced state. Such a forcing anomaly occurs during a solar eclipse, when the Moon's shadow cools part of the Earth's surface. The resulting atmospheric gravity waves are associated with pressure and temperature perturbations, which in principle are detectable both at the surface and aloft. In this study, surface pressure and temperature data from two UK sites at Reading and Lerwick are examined for eclipse-driven gravity wave perturbations during the 20 March 2015 solar eclipse over northwest Europe. Radiosonde wind data from the same two sites are also analysed using a moving parcel analysis method, to determine the periodicities of the waves aloft. On this occasion, the perturbations both at the surface and aloft are found not to be confidently attributable to eclipse-driven gravity waves. We conclude that the complex synoptic weather conditions over the UK at the time of this particular eclipse helped to mask any eclipse-driven gravity waves.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. © 2016 The Authors.
Literature Review of Associations among Attributes of Reported Drinking Water Disease Outbreaks
Ligon, Grant; Bartram, Jamie
2016-01-01
Waterborne disease outbreaks attributed to various pathogens and drinking water system characteristics have adversely affected public health worldwide throughout recorded history. Data from drinking water disease outbreak (DWDO) reports of widely varying breadth and depth were synthesized to investigate associations between outbreak attributes and human health impacts. Among 1519 outbreaks described in 475 sources identified during review of the primarily peer-reviewed, English language literature, most occurred in the U.S., the U.K. and Canada (in descending order). The outbreaks are most frequently associated with pathogens of unknown etiology, groundwater and untreated systems, and catchment realm-associated deficiencies (i.e., contamination events). Relative frequencies of outbreaks by various attributes are comparable with those within other DWDO reviews, with water system size and treatment type likely driving most of the (often statistically-significant at p < 0.05) differences in outbreak frequency, case count and attack rate. Temporal analysis suggests that while implementation of surface (drinking) water management policies is associated with decreased disease burden, further strengthening of related policies is needed to address the remaining burden attributed to catchment and distribution realm-associated deficiencies and to groundwater viral and disinfection-only system outbreaks. PMID:27240387
Scholz, C; Jones, T G; West, M; Ehbair, A M S; Dunn, C; Freeman, C
2016-09-01
The objective of this study was to monitor a newly constructed wetland (CW) in north Wales, UK, to assess whether it contributes to an improvement in water quality (nutrient removal) of a nearby drinking water reservoir. Inflow and outflow of the Free Water Surface (FWS) CW were monitored on a weekly basis and over a period of 6 months. Physicochemical parameters including pH, conductivity and dissolved oxygen (DO) were measured, as well as nutrients and dissolved organic and inorganic carbon (DOC, DIC) concentration. The CW was seen to contribute to water quality improvement; results show that nutrient removal took place within weeks after construction. It was found that 72 % of initial nitrate (N03 (-)), 53 % of initial phosphate (PO4 (3-)) and 35 % of initial biological oxygen demand (BOD) were removed, calculated as a total over the whole sampling period. From our study, it can be concluded that while inorganic nutrients do decline in CWs, the DOC outputs increases. This may suggest that CWs represent a source for DOC. To assess the carbon in- and output a C budget was calculated.
Literature Review of Associations among Attributes of Reported Drinking Water Disease Outbreaks.
Ligon, Grant; Bartram, Jamie
2016-05-27
Waterborne disease outbreaks attributed to various pathogens and drinking water system characteristics have adversely affected public health worldwide throughout recorded history. Data from drinking water disease outbreak (DWDO) reports of widely varying breadth and depth were synthesized to investigate associations between outbreak attributes and human health impacts. Among 1519 outbreaks described in 475 sources identified during review of the primarily peer-reviewed, English language literature, most occurred in the U.S., the U.K. and Canada (in descending order). The outbreaks are most frequently associated with pathogens of unknown etiology, groundwater and untreated systems, and catchment realm-associated deficiencies (i.e., contamination events). Relative frequencies of outbreaks by various attributes are comparable with those within other DWDO reviews, with water system size and treatment type likely driving most of the (often statistically-significant at p < 0.05) differences in outbreak frequency, case count and attack rate. Temporal analysis suggests that while implementation of surface (drinking) water management policies is associated with decreased disease burden, further strengthening of related policies is needed to address the remaining burden attributed to catchment and distribution realm-associated deficiencies and to groundwater viral and disinfection-only system outbreaks.
Intercomparison of standards of absorbed dose between the USSR and the UK
NASA Astrophysics Data System (ADS)
Berlyand, V. A.; Bregadze, J. I.; Burns, J. E.; Dusautoy, A. R.; Sharpe, P. H. G.
1991-05-01
A comparison of national standards of absorbed dose was carried out between the All-Union Research Institute for Physical Technical and Radiotechnical Measurements (VNIIFTRI), USSR, and the National Physical Laboratotry (NPL), UK (United Kingdom). Absorbed dose to water for cobalt 60 gamma radiation was compared by means of Fricke dosimeters and ionization chambers in 1985 and 1986. The primary standards used to derive absorbed dose to water were cavity ionization chambers at NPL and a graphite calorimeter at VNIIFTRI. The ratio of absorbed dose to water, NPL to VNIIFTRI, using Fricke dosimeters was 1.008; using ionization chambers it was 1.007. This agreement is within the estimated uncertainties of the standards and measurement methods.
The UK geochemical environment and cardiovascular diseases: magnesium in food and water.
Davies, B E
2015-06-01
Cardiovascular diseases (CVDs) contribute approximately one-third to noncommunicable diseases in the UK. The central role of magnesium in CVDs (enzyme activity, cardiac signalling, etc.) is well established. Mortality and morbidity rates for CVDs may be inversely related to water hardness, suggesting a role for environmental magnesium. Published official and quasi-official data sources were evaluated to establish a model magnesium intake for a representative adult: standardised reference individual (SRI), standardised reference male (SRM) or standardised reference female (SRF). For typical dietary constituents, only tap water is probably locally derived and bottled water may not be. Fruits and vegetables are imported from many countries, while meat, dairy and cereal products represent a composite of UK source areas. Alcoholic beverages provide magnesium, there is doubt about its absorptive efficiency, and they are not locally derived. A simple model was devised to examine the effect of varying dietary contributions to total daily intake of magnesium. Omitting tap or bottled water, the combined intake, solid food plus alcoholic beverages, is 10.57 mmol Mg (84.5 % RNI) for the SRM and for the SRF, 8.10 mmol Mg (71.7 % RNI). Consumers drinking water derived from reservoirs or rivers, or supplementing it with the purest bottled water, improve their magnesium intake only slightly compared with water containing no magnesium. Choosing bottled water with high magnesium content when the public supply derives from rivers or reservoirs partially satisfies magnesium needs. Real improvement in SRI magnesium nutrition is seen only where water is hard. However, this conclusion cannot be validated until new measurement technologies for body magnesium become available.
Biswas, Subhajit; Jackson, Philippa; Shannon, Rebecca; Dulwich, Katherine; Sukla, Soumi; Dixon, Ronald A
This molecular study is the first report, to the best of our knowledge, on identification of norovirus, NoV GII.4 Sydney 2012 variants, from blue mussels collected from UK coastal waters. Blue mussels (three pooled samples from twelve mussels) collected during the 2013 summer months from UK coastal sites were screened by RT-PCR assays. PCR products of RdRP gene for noroviruses were purified, sequenced and subjected to phylogenetic analysis. All the samples tested positive for NoVs. Sequencing revealed that the NoV partial RdRP gene sequences from two pooled samples clustered with the pandemic "GII.4 Sydney variants" whilst the other pooled sample clustered with the NoV GII.2 variants. This molecular study indicated mussel contamination with pathogenic NoVs even during mid-summer in UK coastal waters which posed potential risk of NoV outbreaks irrespective of season. As the detection of Sydney 2012 NoV from our preliminary study of natural coastal mussels interestingly corroborated with NoV outbreaks in nearby areas during the same period, it emphasizes the importance of environmental surveillance work for forecast of high risk zones of NoV outbreaks. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.
NASA Astrophysics Data System (ADS)
Goni, M. A.
2005-12-01
The recent past history of sea surface temperature (SST) conditions in two wind-dominated upwelling systems, Guaymas Basin (Gulf of California) and Cariaco Basin (Venezuela) was investigated using the alkenone-based UK'37 index. Both of these systems undergo marked seasonal SST changes of 4-10 degrees C, which are associated with wind-driven upwelling and thermal stratification cycles. Both Guaymas and Cariaco Basins are also characterized by suboxic to anoxic bottom waters that result in undisturbed, varved sediments. Confirmation that the seasonal SST trends are accurately incorporated into the UK'37 ratios of sinking particles was achieved using sediment trap samples. Analyses of sediment cores from Guaymas and Cariaco Basins yielded high-resolution (decadal) records of SST conditions in the overlying water column from 1700 to 2000 AD. The trends in the UK'37 index revealed general increases in the SST at both sites over that last 300 years associated with the end of the little ice age. However, in addition to this long-term trend, higher-frequency (~ 50 years) changes in SST that ranged from 1-3 degrees C were observed. We speculate that these decadal trends in SST reflect variations in the intensity of wind-driven upwelling at these sites. Most interestingly, there is a marked contrast in the timing of the SST values between Guaymas and Cariaco so that periods of enhanced upwelling in Guyamas Basin are characterized by decreased upwelling in Cariaco Basin (and vice versa). We propose that these contrasting records reflect differences in the response of wind-driven upwelling to changes in the position of the Intertropical Convergence Zone over the western Atlantic and the subtropical High over the eastern Pacific. The connection between these two upwelling systems and its significance for paleoreconstruction studies will be explored further.
Briggs, Derek E G; Siveter, Derek J; Siveter, David J; Sutton, Mark D; Rahman, Imran A
2017-09-13
Echinoderms are unique in having a water vascular system with tube feet, which perform a variety of functions in living forms. Here, we report the first example of preserved tube feet in an extinct group of echinoderms. The material, from the Silurian Herefordshire Lagerstätte, UK, is assigned to a new genus and species of rhenopyrgid edrioasteroid, Heropyrgus disterminus The tube feet attach to the inner surface of compound interradial plates and form two sets, an upper and a lower, an arrangement never reported previously in an extant or extinct echinoderm. Cover plates are absent and floor plates are separated creating a large permanent entrance to the interior of the oral area. The tube feet may have captured food particles that entered the oral area and/or enhanced respiration. The pentameral symmetry of the oral surface transitions to eight columns in which the plates are vertically offset resulting in a spiral appearance. This change in symmetry may reflect flexibility in the evolutionary development of the axial and extraxial zones in early echinoderm evolution. © 2017 The Author(s).
Acanthamoeba keratitis: the role of domestic tap water contamination in the United Kingdom.
Kilvington, Simon; Gray, Trevor; Dart, John; Morlet, Nigel; Beeching, John R; Frazer, David G; Matheson, Melville
2004-01-01
The incidence of acanthamoeba keratitis (AK) in the UK is some 15 times that in the United States and seven times that in Holland. To investigate reasons for this higher frequency, a study of the role of domestic tap water as a potential source of AK was undertaken. Tap outlets from the homes of 27 patients with culture-proven AK were sampled and cultured for free-living amoebae (FLA). For all Acanthamoeba isolates, mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) and cytochrome oxidase (cox 1/2) sequence typing was performed to determine the similarity between corneal and tap water isolates. FLA, including Acanthamoeba, were isolated from 24 (89%) of 27 homes, and the presence within the homes varied significantly with tap water temperature and location: 19 (76%) of 25 bathroom sink cold taps sampled compared with 6 (24%) of 25 hot and 9 (47%) of 19 kitchen cold taps compared with 3 (16%) of 19 of hot kitchen taps. Acanthamoeba were isolated from 8 (30%) of 27 homes (five bathroom sink cold taps, one cloakroom cold tap, one bath, and one bedroom sink mixer [hot/cold] taps). In six cases, identical Acanthamoeba mtDNA profiles were found for the clinical and home tap water isolates. In keeping with UK plumbing practice, 24 of 27 homes had internal roof water storage tanks to supply domestic taps, but the mains fed the kitchen cold tap. Water storage tanks promote colonization of domestic water with FLA, including Acanthamoeba, and hence increase the risk of AK. This accounts for the significantly greater incidence of AK in the UK and supports advice to avoid using tap water in contact lens care routines.
NASA Astrophysics Data System (ADS)
Lunt, Mark; Rigby, Matt; Manning, Alistair; O'Doherty, Simon; Stavert, Ann; Stanley, Kieran; Young, Dickon; Pitt, Joseph; Bauguitte, Stephane; Allen, Grant; Helfter, Carole; Palmer, Paul
2017-04-01
The Greenhouse gAs Uk and Global Emissions (GAUGE) project aims to quantify the magnitude and uncertainty of key UK greenhouse gas emissions more robustly than previously achieved. Measurements of methane have been taken from a number of tall-tower and surface sites as well as mobile measurement platforms such as a research aircraft and a ferry providing regular transects off the east coast of the UK. Using the UK Met Office's atmospheric transport model, NAME, and a novel Bayesian inversion technique we present estimates of methane emissions from the UK from a number of different combinations of sites to show the robustness of the UK total emissions to network configuration. The impact on uncertainties will be discussed, focusing on the usefulness of the various measurement platforms for constraining UK emissions. We will examine the effects of observation selection and how a priori assumptions about model uncertainty can affect the emission estimates, even within a data-driven hierarchical inversion framework. Finally, we will show the impact of the resolution of the meteorology used to drive the NAME model on emissions estimates, and how to rationalise our understanding of the ability of transport models to represent reality.
Copper disinfection ban causes storm.
Lester, Alan
2013-05-01
Since 1 February this year, under the EU's Biocidal Products Directive, it has been illegal to sell or use water treatment systems that use elemental copper, a practice employed historically by a significant number of UK healthcare facilities to combat Legionella. Alan Lester, managing director of specialist supplier of 'environmentally-friendly' water treatment systems, Advanced Hydro, says the ban has caused 'a storm of giant proportion,' with advocates of copper ion-based treatment systems arguing that this disinfection method dates back 3,000 years to Egyptian times, making it an 'undoubtedly proven' technology. Here he explains why the ban came into force, considers why the UK's Health and Safety Executive (HSE) is seeking a derogation, looks at the ban's likely impact, and gives a personal viewpoint on the 'pros and cons' of some of the alternative treatment technologies, including a titanium dioxide-based system marketed by Advanced Hydro itself in the UK.
White, Charlotte A.; Sylvester-Bradley, Roger; Berry, Peter M.
2015-01-01
Root length density (RLD) was measured to 1 m depth for 17 commercial crops of winter wheat (Triticum aestivum) and 40 crops of winter oilseed rape [Brassica napus; oilseed rape (OSR)] grown in the UK between 2004 and 2013. Taking the critical RLD (cRLD) for water capture as 1cm cm–3, RLDs appeared inadequate for full water capture on average below a depth of 0.32 m for winter wheat and below 0.45 m for OSR. These depths compare unfavourably (for wheat) with average depths of ‘full capture’ of 0.86 m and 0.48 m, respectively, determined for three wheat crops and one OSR crop studied in the 1970s and 1980s, and treated as references here. A simple model of water uptake and yield indicated that these shortfalls in wheat and OSR rooting compared with the reference data might be associated with shortfalls of up to 3.5 t ha–1 and 1.2 t ha–1, respectively, in grain yields under water-limited conditions, as increasingly occur through climate change. Coupled with decreased summer rainfall, poor rooting of modern arable crops could explain much of the yield stagnation that has been observed on UK farms since the 1990s. Methods of monitoring and improving rooting under commercial conditions are reviewed and discussed. PMID:25750427
Caraballo, Manuel A; Rötting, Tobias S; Silva, Verónica
2010-09-15
Three laboratory column experiments were performed to test the suitability of two different MgO-rich reagents for removal of Mn and Al from the out-flowing waters of Shilbottle passive treatment system (Northumberland, UK). The input water was doped with 100 mg/L Zn in order to extrapolate results to waters in sulphide mining districts. One column was filled with a Dispersed Alkaline Substrate (DAS) containing 12.5% (v/v) caustic magnesia precipitator dust (CMPD) from Spain mixed with wood shavings, two columns were filled with DAS containing wood shavings and 12.5% or 25% (v/v), respectively, of dolomitic lime precipitator dust (DLPD) from Thrislington, UK. The two columns containing 12.5% of CMPD or DLPD completely removed the contaminants from the inflow water during the first 6 weeks of the experiment (mean removal of 88 mg/L Al, 96 mg/L Zn and 37 mg/L Mn), operating at an acidity load of 140 g acidity/m(2)day. At this moment, a substantial increase of the Al and Mn water concentration in the out-flowing waters of Shilbottle occurred (430 g acidity/m(2)day), leading to passivation of the reactive material and to the development of preferential flow paths within less than another 6 weeks, probably mainly due to Al precipitates. Al should be removed prior to MgO treatment. Copyright 2010 Elsevier B.V. All rights reserved.
New perspectives on the passive treatment of ferruginous circumneutral mine waters in the UK.
Sapsford, D J
2013-11-01
This paper examines major physico-chemical processes during the passive treatment of ferruginous circumneutral drainage from abandoned coal mines in the UK. Data collected over several years of studies on mine water treatment systems shed new light on the relative importance of hydraulics, settling velocity, Fe(II) oxidation rates and cascade aeration, which, in turn, informs the design of future systems. This paper demonstrates that (1) the complex settling behaviour of Fe(III) precipitates may be described by a first-order volumetric process and that settling rate is different for different mine waters; (2) the hydraulic efficiency (ratio of time to peak tracer concentration to nominal residence time) of the settling ponds studied was widely variable at low flow rates in comparison to constructed wetlands; (3) aeration cascades contribute dissolved oxygen and lead to a rise in pH due to CO2 degassing, which are very important in reducing the required time for iron oxidation and removal; (4) for at least 10 of the 30 sites examined, modelling of the rates of Fe(II) oxidation and particulate settling reveals that removal of iron is primarily dependent on settling rate; and (5) that substantial increases in pH can be brought about by forced aeration of mine water over several hours. Findings of this study apply to the majority of coal mine water treatment sites in the UK and may have broader application to other ferruginous waters with circumneutral pH or after treatment to increase pH.
NASA Astrophysics Data System (ADS)
Clark, D. B.; Mercado, L. M.; Sitch, S.; Jones, C. D.; Gedney, N.; Best, M. J.; Pryor, M.; Rooney, G. G.; Essery, R. L. H.; Blyth, E.; Boucher, O.; Harding, R. J.; Huntingford, C.; Cox, P. M.
2011-09-01
The Joint UK Land Environment Simulator (JULES) is a process-based model that simulates the fluxes of carbon, water, energy and momentum between the land surface and the atmosphere. Many studies have demonstrated the important role of the land surface in the functioning of the Earth System. Different versions of JULES have been employed to quantify the effects on the land carbon sink of climate change, increasing atmospheric carbon dioxide concentrations, changing atmospheric aerosols and tropospheric ozone, and the response of methane emissions from wetlands to climate change. This paper describes the consolidation of these advances in the modelling of carbon fluxes and stores, in both the vegetation and soil, in version 2.2 of JULES. Features include a multi-layer canopy scheme for light interception, including a sunfleck penetration scheme, a coupled scheme of leaf photosynthesis and stomatal conductance, representation of the effects of ozone on leaf physiology, and a description of methane emissions from wetlands. JULES represents the carbon allocation, growth and population dynamics of five plant functional types. The turnover of carbon from living plant tissues is fed into a 4-pool soil carbon model. The process-based descriptions of key ecological processes and trace gas fluxes in JULES mean that this community model is well-suited for use in carbon cycle, climate change and impacts studies, either in standalone mode or as the land component of a coupled Earth system model.
The UK water crisis: What actions the government and private sector need to take.
Skelton, Emmeline
2015-01-01
The paper discusses why resilience is increasingly important for companies to measure and address, thinking about relevant issues such as climate change and extreme weather. It gives insight on how companies measure their resilience and that it is more than a business continuity issue; indeed, it is a board issue. The paper looks at the role of regulation for companies with national critical infrastructure in putting in resilience guidelines and discusses the benefits of regulation in resilience, presenting a case study of the UK Water Services Regulation Authority resilience guidelines.
Isolation of pandemic Vibrio parahaemolyticus from UK water and shellfish produce.
Powell, Andy; Baker-Austin, Craig; Wagley, Sariqa; Bayley, Amanda; Hartnell, Rachel
2013-05-01
Vibrio parahaemolyticus is a Gram-negative, halophilic bacterium found commonly in temperate and warm estuarine waters worldwide. V. parahaemolyticus is considered an emerging bacterial pathogen in Europe and has been responsible for several recent seafood-associated outbreaks. During ad hoc testing of raw shellfish produce in May 2012, pandemic group (O3:K6) V. parahaemolyticus was isolated from Pacific oysters (Crassostrea gigas), harvested in Southern England. Follow-on testing of water and shellfish, encompassing a small number geographically diverse sites, also retrieved pandemic group isolates. These strains are amongst the most northerly pandemic strains described to date and represent the first instance of pandemic V. parahaemolyticus isolated in the UK, highlighting the expanding geographical distribution of these foodborne pathogens in the environment.
Variability of Indonesian Throughflow and Borneo Runoff During the Last 14 kyr
NASA Astrophysics Data System (ADS)
Hendrizan, Marfasran; Kuhnt, Wolfgang; Holbourn, Ann
2017-10-01
We present a high-resolution ( 20 to 100 years temporal resolution) reconstruction of hydrological changes in the Makassar Strait over the last 14 kyr from Core SO217-18517 retrieved off the Mahakam Delta (1°32.198'S, 117°33.756'E; 698 m water depth) during the SO217 Makassar-Java Cruise. Sea surface temperatures, based on Mg/Ca of Globigerinoides ruber and alkenone UK'37, and seawater δ18O reconstructions, based on G. ruber δ18O and Mg/Ca, in combination with sortable silt grain size measurements and X-ray fluorescence (XRF) core scanner derived elemental data provide evidence for increased precipitation during the Bølling-Allerød (BA) and early Holocene and for warmer and more saline surface waters and a decrease in the intensity of the Indonesian Throughflow (ITF) during the Younger Dryas (YD). XRF derived Log (Zr/Rb) records, sortable silt data and increased sedimentation rates indicate decreased winnowing, interpreted as a slowdown of the ITF thermocline flow during the YD. We attribute this decline in ITF intensity to slowdown of the Atlantic meridional overturning circulation during the YD. We suggest that changes in Makassar Strait surface hydrology during this interval of Northern Hemisphere cooling and Southern Hemisphere warming were related to a southward displacement of the Intertropical Convergence Zone.
Virtual Research Environments for Natural Hazard Modelling
NASA Astrophysics Data System (ADS)
Napier, Hazel; Aldridge, Tim
2017-04-01
The Natural Hazards Partnership (NHP) is a group of 17 collaborating public sector organisations providing a mechanism for co-ordinated advice to government and agencies responsible for civil contingency and emergency response during natural hazard events. The NHP has set up a Hazard Impact Model (HIM) group tasked with modelling the impact of a range of UK hazards with the aim of delivery of consistent hazard and impact information. The HIM group consists of 7 partners initially concentrating on modelling the socio-economic impact of 3 key hazards - surface water flooding, land instability and high winds. HIM group partners share scientific expertise and data within their specific areas of interest including hydrological modelling, meteorology, engineering geology, GIS, data delivery, and modelling of socio-economic impacts. Activity within the NHP relies on effective collaboration between partners distributed across the UK. The NHP are acting as a use case study for a new Virtual Research Environment (VRE) being developed by the EVER-EST project (European Virtual Environment for Research - Earth Science Themes: a solution). The VRE is allowing the NHP to explore novel ways of cooperation including improved capabilities for e-collaboration, e-research, automation of processes and e-learning. Collaboration tools are complemented by the adoption of Research Objects, semantically rich aggregations of resources enabling the creation of uniquely identified digital artefacts resulting in reusable science and research. Application of the Research Object concept to HIM development facilitates collaboration, by encapsulating scientific knowledge in a shareable format that can be easily shared and used by partners working on the same model but within their areas of expertise. This paper describes the application of the VRE to the NHP use case study. It outlines the challenges associated with distributed partnership working and how they are being addressed in the VRE. A case study is included focussing on the application of Research Objects to development work for the surface water flooding hazard impact model, a key achievement for the HIM group.
Helical piles: an innovative foundation design option for offshore wind turbines.
Byrne, B W; Houlsby, G T
2015-02-28
Offshore wind turbines play a key part in the renewable energy strategy in the UK and Europe as well as in other parts of the world (for example, China). The majority of current developments, certainly in UK waters, have taken place in relatively shallow water and close to shore. This limits the scale of the engineering to relatively simple structures, such as those using monopile foundations, and these have been the most common design to date, in UK waters. However, as larger turbines are designed, or they are placed in deeper water, it will be necessary to use multi-footing structures such as tripods or jackets. For these designs, the tension on the upwind footing becomes the critical design condition. Driven pile foundations could be used, as could suction-installed foundations. However, in this paper, we present another concept-the use of helical pile foundations. These foundations are routinely applied onshore where large tension capacities are required. However, for use offshore, a significant upscaling of the technology will be needed, particularly of the equipment required for installation of the piles. A clear understanding of the relevant geotechnical engineering will be needed if this upscaling is to be successful. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
4D ERT Monitoring of Subsurface Water Pipe Leakage During a Controlled Field Experiment
NASA Astrophysics Data System (ADS)
Inauen, C.; Chambers, J. E.; Wilkinson, P. B.; Meldrum, P.; Swift, R. T.; Uhlemann, S.; Gunn, D.; Dashwood, B.; Taxil, J.; Curioni, G.
2016-12-01
Locating and delineating leakage from subsurface pipelines is an important task for civil engineers. 4D Electrical Resistivity Tomography (ERT) allows changes in subsurface resistivity to be imaged at a high spatial and temporal resolution in a minimally invasive manner. It is therefore a promising tool to supplement conventional point-sensing techniques to monitor subsurface flow processes. To assess the efficacy of ERT for pipe leakage monitoring several controlled leak experiments were carried out at a test site in Blagdon, Bristol, UK. To simulate the leak, a plastic pipe with a hole was buried below a flat, grassed area at a depth of 0.7 m, representing a standard UK mains water pipe installation. The water table at the site lies well below the surface meaning that the experiment took entirely place in the vadose zone, where changes in resistivity are primarily sensitive to water content variations. The ERT array covered an area of 6.5m x 6.5m around the leak location. Data acquisition was carried out with the BGS PRIME (Proactive Infrastructure Monitoring and Evaluation) system, which facilitates remote scheduling and autonomous ERT data collection and transmission. To obtain the resistivity changes of the subsurface a 4D inversion was carried out using a Gauss-Newton approach with spatial and temporal smoothness constraints. We were able to reliably observe the onset, spread and cessation of the leakage. Measurements from in-situ soil sensors at several depths above and below the leak complemented the ERT data and allowed us to assess their reliability and directly relate them to hydrogeological processes. Moreover, through experimental tests with soil samples from the test area, a Waxman-Smits relation was obtained to directly convert the changes in electrical resistivity to gravimetric soil moisture content. With future experiments on the test site more work is planned towards survey optimization, automated processing and tracking of leakage plumes.
NASA Astrophysics Data System (ADS)
Morris, David J.; Pinnegar, John K.; Maxwell, David L.; Dye, Stephen R.; Fernand, Liam J.; Flatman, Stephen; Williams, Oliver J.; Rogers, Stuart I.
2018-01-01
The datasets described here bring together quality-controlled seawater temperature measurements from over 130 years of departmental government-funded marine science investigations in the UK (United Kingdom). Since before the foundation of a Marine Biological Association fisheries laboratory in 1902 and through subsequent evolutions as the Directorate of Fisheries Research and the current Centre for Environment Fisheries & Aquaculture Science, UK government marine scientists and observers have been collecting seawater temperature data as part of oceanographic, chemical, biological, radiological, and other policy-driven research and observation programmes in UK waters. These datasets start with a few tens of records per year, rise to hundreds from the early 1900s, thousands by 1959, and hundreds of thousands by the 1980s, peaking with > 1 million for some years from 2000 onwards. The data source systems vary from time series at coastal monitoring stations or offshore platforms (buoys), through repeated research cruises or opportunistic sampling from ferry routes, to temperature extracts from CTD (conductivity, temperature, depth) profiles, oceanographic, fishery and plankton tows, and data collected from recreational scuba divers or electronic devices attached to marine animals. The datasets described have not been included in previous seawater temperature collation exercises (e.g. International Comprehensive Ocean-Atmosphere Data Set, Met Office Hadley Centre sea surface temperature data set, the centennial in situ observation-based estimates of sea surface temperatures), although some summary data reside in the British Oceanographic Data Centre (BODC) archive, the Marine Environment Monitoring and Assessment National (MERMAN) database and the International Council for the Exploration of the Sea (ICES) data centre. We envisage the data primarily providing a biologically and ecosystem-relevant context for regional assessments of changing hydrological conditions around the British Isles, although cross-matching with satellite-derived data for surface temperatures at specific times and in specific areas is another area in which the data could be of value (see e.g. Smit et al., 2013). Maps are provided indicating geographical coverage, which is generally within and around the UK Continental Shelf area, but occasionally extends north from Labrador and Greenland to east of Svalbard and southward to the Bay of Biscay. Example potential uses of the data are described using plots of data in four selected groups of four ICES rectangles covering areas of particular fisheries interest. The full dataset enables extensive data synthesis, for example in the southern North Sea where issues of spatial and numerical bias from a data source are explored. The full dataset also facilitates the construction of long-term temperature time series and an examination of changes in the phenology (seasonal timing) of ecosystem processes. This is done for a wide geographic area with an exploration of the limitations of data coverage over long periods. Throughout, we highlight and explore potential issues around the simple combination of data from the diverse and disparate sources collated here. The datasets are available on the Cefas Data Hub (https://www.cefas.co.uk/cefas-data-hub/). The referenced data sources are listed in Sect. 5.
Improving UK Chalk hydrometeorology across spatial scales using a small hydrometeorological network
NASA Astrophysics Data System (ADS)
Rosolem, Rafael; Iwema, Joost; Rahman, Mostaquimur; Desilets, Darin; Koltermann da Silva, Juliana
2016-04-01
Chalk in the UK acts as a primary aquifer providing up to 80% of the public water supply locally. Chalk outcrops are located over most of southern and eastern England. Despite its importance, the characterization of Chalk in hydrometeorological models is still very limited. There is a need for a comprehensive and coherent integration of observations and modeling efforts across spatial scales for better understanding Chalk hydrometeorology. Here we introduce the "A MUlti-scale Soil moisture-Evapotranspiration Dynamics" (AMUSED) project. AMUSED goal is to better identify the key dominant processes controlling changes in soil moisture and surface fluxes (e.g., evapotranspiration) across spatial scales by combining ground-based observations with hydrometeorological models and satellite remote sensing products. The AMUSED observational platform consists of three sites located in Upper Chalk region of the Lambourn Catchment located in southern England covering approximately 2 square-km characterized by distinct combinations of soil and vegetation types. The network includes standard meteorological measurements, an eddy covariance system for turbulent fluxes and cosmic-ray neutron sensors for integrated soil moisture estimates at intermediate scales. Here we present our initial results from our three sites.
Fluctuations in the meiofauna of the Aufwuchs community in a brackish-water lagoon
NASA Astrophysics Data System (ADS)
Little, Colin
1986-08-01
The organization of the Aufwuchs community in a brackish-water lagoon (Swanpool, Falmouth, U.K.) is described. Changes in the population densities of encrusting bryozoans and mobile meiofauna are described for a period of 3 years. Most meiofaunal species reached peak densities in the spring (January-March). These included tardigrades ( Macrobiotus sp.), oligochaetes ( Nais elinguis, Chaetogaster diaphanus), the harpacticoid copepod Schizopera clandestina, ostracods, the nematodes Dichromadora geophila and Theristus spp., and possibly the nematodes Chromadorina germanica and Atrochromadora microlaima. Other meiofaunal populations peaked in summer (July-September), and these included the chironomid Chironomus salinarius, the harpacticoid copepod Nitocra spinipes and the nematode Adoncholaimus thalassophygas. Two further species, the mite Halacarus balticus and the nematode Aphelencoides sp., showed irregular bursts in numbers. It is concluded that the spring-peaking species increased in numbers dependent upon the growth of the Aufwuchs, and particularly of the surface film of diatoms, while the summer-peaking species may have been controlled more by limiting values of salinity and temperature. These conclusions are contrasted with the general view of salinity as the over-riding factor in brackish-water ecosystems.
NASA Astrophysics Data System (ADS)
Xia, Xilin; Liang, Qiuhua; Ming, Xiaodong; Hou, Jingming
2017-05-01
Numerical models solving the full 2-D shallow water equations (SWEs) have been increasingly used to simulate overland flows and better understand the transient flow dynamics of flash floods in a catchment. However, there still exist key challenges that have not yet been resolved for the development of fully dynamic overland flow models, related to (1) the difficulty of maintaining numerical stability and accuracy in the limit of disappearing water depth and (2) inaccurate estimation of velocities and discharges on slopes as a result of strong nonlinearity of friction terms. This paper aims to tackle these key research challenges and present a new numerical scheme for accurately and efficiently modeling large-scale transient overland flows over complex terrains. The proposed scheme features a novel surface reconstruction method (SRM) to correctly compute slope source terms and maintain numerical stability at small water depth, and a new implicit discretization method to handle the highly nonlinear friction terms. The resulting shallow water overland flow model is first validated against analytical and experimental test cases and then applied to simulate a hypothetic rainfall event in the 42 km2 Haltwhistle Burn, UK.
Heathwaite, A.L.; Johnes, P.J.; Peters, N.E.
1996-01-01
The roles of nitrogen (N) and phosphorus (P) as key nutrients determining the trophic status of water bodies are examined, and evidence reviewed for trends in concentrations of N and P species which occur in freshwaters, primarily in northern temperate environments. Data are reported for water bodies undergoing eutrophication and acidification, especially water bodies receiving increased nitrogen inputs through the atmospheric deposition of nitrogen oxides (NOx). Nutrient loading on groundwaters and surface freshwaters is assessed with respect to causes and rates of (change, relative rates of change for N and P, and implications of change for the future management of lakes, rivers and groundwaters. In particular, the nature and emphasis of studies for N species and P fractions in lakes versus rivers and groundwaters are contrasted. This review paper primarily focuses on results from North America and Europe, particularly for the UK where a wide range of data sets exists. Few nutrient loading data have been published on water bodies in less developed countries; however, some of the available data are presented to provide a global perspective. In general, N and P concentrations have increased dramatically (>20 times background concentrations) in many areas and causes vary considerably, ranging from urbanization to changes in agricultural practices.
Kowalski, Ania M.; Gooding, Mike; Ferrante, Ariel; Slafer, Gustavo A.; Orford, Simon; Gasperini, Debora; Griffiths, Simon
2016-01-01
Reduced height 8 (Rht8) is the main alternative to the GA-insensitive Rht alleles in hot and dry environments where it reduces plant height without yield penalty. The potential of Rht8 in northern-European wheat breeding remains unclear, since the close linkage with the photoperiod-insensitive allele Ppd-D1a is unfavourable in the relatively cool summers. In the present study, two near-isogenic lines (NILs) contrasting for the Rht8/tall allele from Mara in a UK-adapted and photoperiod-sensitive wheat variety were evaluated in trials with varying nitrogen fertiliser (N) treatments and water regimes across sites in the UK and Spain. The Rht8 introgression was associated with a robust height reduction of 11% regardless of N treatment and water regime and the Rht8 NIL was more resistant to root-lodging at agronomically-relevant N levels than the tall NIL. In the UK with reduced solar radiation over the growing season than the site in Spain, the Rht8 NIL showed a 10% yield penalty at standard agronomic N levels due to concomitant reduction in grain number and spike number whereas grain weight and harvest index were not significantly different to the tall NIL. The yield penalty associated with the Rht8 introgression was overcome at low N and in irrigated conditions in the UK, and in the high-temperature site in Spain. Decreased spike length and constant spikelet number in the Rht8 NIL resulted in spike compaction of 15%, independent of N and water regime. The genetic interval of Rht8 overlaps with the compactum gene on 2DS, raising the possibility of the same causative gene. Further genetic dissection of these loci is required. PMID:27212788
A UK portrait of wind-induced undercatch in rainfall measurement
NASA Astrophysics Data System (ADS)
Pollock, Michael; Quinn, Paul; O'Donnell, Greg; Colli, Matteo; Dutton, Mark; Black, Andrew; Wilkinson, Mark; Kilsby, Chris; Stagnaro, Mattia; Lanza, Luca; O'Connell, Enda
2017-04-01
Rainfall is vital to life; civilisation depends upon it. Changing local and regional rainfall regimes toward more intense storm events (e.g. in the UK), increases the existing challenge of accurately measuring and modelling rainfall. Data from rain gauges, often considered to provide the most accurate practicable measure of precipitation at a point in space in time, play a critical role. They are used for, inter alia, flood forecasting and flood risk management; radar calibration and numerical weather prediction models; urban planning and drainage; and water resource management and hydrological modelling. Despite the key importance of these measurements, they remain susceptible to fundamental sources of systematic error which are often not considered when rainfall data are used. Inaccuracies in measurements are compounded in modelling applications by producing potentially misleading or incorrect results; it is therefore of great importance to understand and present uncertainty in observations. Standard practice is to mount rain gauges above the ground surface. This configuration obstructs the prevailing wind which causes an acceleration of airflow above the orifice. Precipitation is deflected away from the orifice and lands 'downstream' of the area represented by the gauge measurement, reducing its collection efficiency (CE). This phenomenon is commonly referred to as 'wind-induced undercatch'. The physical shape of a gauge bears a significant impact on its CE. Computational Fluid Dynamics (CFD) simulations are used to investigate how different shapes of precipitation gauge are affected by the wind. CFD modelling is supported by high-resolution field measurements at several exposed 'Hydro-Met' research stations in the UK. These sites are occupied by rain gauges which are scrutinised in the CFD analyses. The reference measurements at all sites are made within a WMO reference pit, where the rain gauge is mounted with its orifice at ground level and surrounded by an appropriate grid structure. 'Undercatch' exhibited within UK storms, not captured by operational gauge networks in the UK, is quantified and presented in this study. Results from CFD modelling and the field studies show that gauge shape and mounting height significantly affect the extent of the undercatch. 'Aerodynamic' gauges following a 'champagne flute' or a 'funnel' profile were demonstrated by both to have significant advantages over conventional gauge shapes, in terms of improving the CE. This study presents the latest analyses, and proposes the possible extent of rainfall underestimation within the UK, with particular reference to its hydrology.
An empirical approach to improving tidal predictions using recent real-time tide gauge data
NASA Astrophysics Data System (ADS)
Hibbert, Angela; Royston, Samantha; Horsburgh, Kevin J.; Leach, Harry
2014-05-01
Classical harmonic methods of tidal prediction are often problematic in estuarine environments due to the distortion of tidal fluctuations in shallow water, which results in a disparity between predicted and observed sea levels. This is of particular concern in the Bristol Channel, where the error associated with tidal predictions is potentially greater due to an unusually large tidal range of around 12m. As such predictions are fundamental to the short-term forecasting of High Water (HW) extremes, it is vital that alternative solutions are found. In a pilot study, using a year-long observational sea level record from the Port of Avonmouth in the Bristol Channel, the UK National Tidal and Sea Level Facility (NTSLF) tested the potential for reducing tidal prediction errors, using three alternatives to the Harmonic Method of tidal prediction. The three methods evaluated were (1) the use of Artificial Neural Network (ANN) models, (2) the Species Concordance technique and (3) a simple empirical procedure for correcting Harmonic Method High Water predictions based upon a few recent observations (referred to as the Empirical Correction Method). This latter method was then successfully applied to sea level records from an additional 42 of the 45 tide gauges that comprise the UK Tide Gauge Network. Consequently, it is to be incorporated into the operational systems of the UK Coastal Monitoring and Forecasting Partnership in order to improve short-term sea level predictions for the UK and in particular, the accurate estimation of HW extremes.
Forecasting surface water flooding hazard and impact in real-time
NASA Astrophysics Data System (ADS)
Cole, Steven J.; Moore, Robert J.; Wells, Steven C.
2016-04-01
Across the world, there is increasing demand for more robust and timely forecast and alert information on Surface Water Flooding (SWF). Within a UK context, the government Pitt Review into the Summer 2007 floods provided recommendations and impetus to improve the understanding of SWF risk for both off-line design and real-time forecasting and warning. Ongoing development and trial of an end-to-end real-time SWF system is being progressed through the recently formed Natural Hazards Partnership (NHP) with delivery to the Flood Forecasting Centre (FFC) providing coverage over England & Wales. The NHP is a unique forum that aims to deliver coordinated assessments, research and advice on natural hazards for governments and resilience communities across the UK. Within the NHP, a real-time Hazard Impact Model (HIM) framework has been developed that includes SWF as one of three hazards chosen for initial trialling. The trial SWF HIM system uses dynamic gridded surface-runoff estimates from the Grid-to-Grid (G2G) hydrological model to estimate the SWF hazard. National datasets on population, infrastructure, property and transport are available to assess impact severity for a given rarity of SWF hazard. Whilst the SWF hazard footprint is calculated in real-time using 1, 3 and 6 hour accumulations of G2G surface runoff on a 1 km grid, it has been possible to associate these with the effective rainfall design profiles (at 250m resolution) used as input to a detailed flood inundation model (JFlow+) run offline to produce hazard information resolved to 2m resolution. This information is contained in the updated Flood Map for Surface Water (uFMfSW) held by the Environment Agency. The national impact datasets can then be used with the uFMfSW SWF hazard dataset to assess impacts at this scale and severity levels of potential impact assigned at 1km and for aggregated county areas in real-time. The impact component is being led by the Health and Safety Laboratory (HSL) within the NHP. Flood Guidance within the FFC employs the national Flood Risk Matrix, which categorises potential impacts into minimal, minor, significant and severe, and Likelihood, into very low, low, medium and high classes, and the matrix entries then define the Overall Flood Risk as very low, low, medium and high. Likelihood is quantified by running G2G with Met Office ensemble rainfall inputs that in turn allows a probability to be assigned to the SWF hazard and associated impact. This overall procedure is being trialled and refined off-line by CEH and HSL using case study data, and at the same time implemented as a pre-operational test system at the Met Office for evaluation by FFC (a joint Environment Agency and Met Office centre for flood forecasting) in 2016.
Modelling Soil Heat and Water Flow as a Coupled Process in Land Surface Models
NASA Astrophysics Data System (ADS)
García González, Raquel; Verhoef, Anne; Vidale, Pier Luigi; Braud, Isabelle
2010-05-01
To improve model estimates of soil water and heat flow by land surface models (LSMs), in particular in the first few centimetres of the near-surface soil profile, we have to consider in detail all the relevant physical processes involved (see e.g. Milly, 1982). Often, thermal and iso-thermal vapour fluxes in LSMs are neglected and the simplified Richard's equation is used as a result. Vapour transfer may affect the water fluxes and heat transfer in LSMs used for hydrometeorological and climate simulations. Processes occurring in the top 50 cm soil may be relevant for water and heat flux dynamics in the deeper layers, as well as for estimates of evapotranspiration and heterotrophic respiration, or even for climate and weather predictions. Water vapour transfer, which was not incorporated in previous versions of the MOSES/JULES model (Joint UK Land Environment Simulator; Cox et al., 1999), has now been implemented. Furthermore, we also assessed the effect of the soil vertical resolution on the simulated soil moisture and temperature profiles and the effect of the processes occurring at the upper boundary, mainly in terms of infiltration rates and evapotranspiration. SiSPAT (Simple Soil Plant Atmosphere Transfer Model; Braud et al., 1995) was initially used to quantify the changes that we expect to find when we introduce vapour transfer in JULES, involving parameters such as thermal vapour conductivity and diffusivity. Also, this approach allows us to compare JULES to a more complete and complex numerical model. Water vapour flux varied with soil texture, depth and soil moisture content, but overall our results suggested that water vapour fluxes change temperature gradients in the entire soil profile and introduce an overall surface cooling effect. Increasing the resolution smoothed and reduced temperature differences between liquid (L) and liquid/vapour (LV) simulations at all depths, and introduced a temperature increase over the entire soil profile. Thermal gradients rather than soil water potential gradients seem to cause temporal and spatial (vertical) soil temperature variability. We conclude that a multi-soil layer configuration may improve soil water dynamics, heat transfer and coupling of these processes, as well as evapotranspiration estimates and land surface-atmosphere coupling. However, a compromise should be reached between numerical and process-simulation aspects. References: Braud I., A.C. Dantas-Antonino, M. Vauclin, J.L. Thony and P. Ruelle, 1995b: A Simple Soil Plant Atmo- sphere Transfer model (SiSPAT), Development and field verification, J. Hydrol, 166: 213-250 Cox, P.M., R.A. Betts, C.B. Bunton, R.L.H. Essery, P.R. Rowntree, and J. Smith (1999), The impact of new land surface physics on the GCM simulation of climate and climate sensitivity. Clim. Dyn., 15, 183-203. Milly, P.C.D., 1982. Moisture and heat transport in hysteric inhomogeneous porous media: a matric head- based formulation and a numerical model, Water Resour. Res., 18:489-498
Experimental study of hydraulics and sediment capture efficiency in catchbasins.
Tang, Yangbo; Zhu, David Z; Rajaratnam, N; van Duin, Bert
2016-12-01
Catchbasins (also known as gully pot in the UK and Australia) are used to receive surface runoff and drain the stormwater into storm sewers. The recent interest in catchbasins is to improve their effectiveness in removing sediments in stormwater. An experimental study was conducted to examine the hydraulic features and sediment capture efficiency in catchbasins, with and without a bottom sump. A sump basin is found to increase the sediment capture efficiency significantly. The effect of inlet control devices, which are commonly used to control the amount of flow into the downstream storm sewer system, is also studied. These devices will increase the water depth in the catchbasin and increase the sediment capture efficiency. Equations are developed for predicting the sediment capture efficiency in catchbasins.
Air-sea fluxes and satellite-based estimation of water masses formation
NASA Astrophysics Data System (ADS)
Sabia, Roberto; Klockmann, Marlene; Fernandez-Prieto, Diego; Donlon, Craig
2015-04-01
Recent work linking satellite-based measurements of sea surface salinity (SSS) and sea surface temperature (SST) with traditional physical oceanography has demonstrated the capability of generating routinely satellite-derived surface T-S diagrams [1] and analyze the distribution/dynamics of SSS and its relative surface density with respect to in-situ measurements. Even more recently [2,3], this framework has been extended by exploiting these T-S diagrams as a diagnostic tool to derive water masses formation rates and areas. A water mass describes a water body with physical properties distinct from the surrounding water, formed at the ocean surface under specific conditions which determine its temperature and salinity. The SST and SSS (and thus also density) at the ocean surface are largely determined by fluxes of heat and freshwater. The surface density flux is a function of the latter two and describes the change of the density of seawater at the surface. To obtain observations of water mass formation is of great interest, since they serve as indirect observations of the thermo-haline circulation. The SSS data which has become available through the SMOS [4] and Aquarius [5] satellite missions will provide the possibility of studying also the effect of temporally-varying SSS fields on water mass formation. In the present study, the formation of water masses as a function of SST and SSS is derived from the surface density flux by integrating the latter over a specific area and time period in bins of SST and SSS and then taking the derivative of the total density flux with respect to density. This study presents a test case using SMOS SSS, OSTIA SST, as well as Argo ISAS SST and SSS for comparison, heat fluxes from the NOCS Surface Flux Data Set v2.0, OAFlux evaporation and CMORPH precipitation. The study area, initially referred to the North Atlantic, is extended over two additional ocean basins and the study period covers the 2011-2012 timeframe. Yearly, seasonal and monthly water mass formation rates for different SST and SSS ranges are presented. The formation peaks are remapped geographically, to analyze the extent of the formation area. Water mass formation derived from SMOS and OSTIA compares well with the results obtained from in-situ data, although slight differences in magnitude and peak location occur. Known water masses can then be identified. Ongoing/future work aims at extending this study along different avenues by: 1) expand systematically the spatial and temporal domain of the study to additional ocean basins and to the entire time period of available SSS observations from SMOS/Aquarius; 2) perform a thorough error propagation to assess how errors in satellite SSS and SST translate into errors in water masses formation rates and geographical areas extent; and 3) explore the different options to connect the surface information to the vertical buoyancy structure to assess potential density instability (e.g., Turner angle). References [1] Sabia, R., M. Klockmann, D. Fernández-Prieto, and C. Donlon (2014), A first estimation of SMOS-based ocean surface T-S diagrams, J. Geophys. Res. Oceans, 119, 7357-7371, doi:10.1002/2014JC010120. [2] Klockmann, M., R. Sabia, D. Fernández-Prieto, C. Donlon, J. Font; Towards an estimation of water masses formation areas from SMOS-based T-S diagrams; EGU general assembly 2014, April 27-May 2, 2014. [3] Klockmann, M., R. Sabia, D. Fernández-Prieto, C. Donlon, Linking satellite SSS and SST to water mass formation; Ocean salinity science and salinity remote sensing workshop, Exeter, UK, November 26-28, 2014. [4] Font, J., A. Camps, A. Borges, M. Martín-Neira, J. Boutin, N. Reul, Y. H. Kerr, A. Hahne, and S. Mecklenburg, "SMOS: The challenging sea surface salinity measurement from space," Proceedings of the IEEE, vol. 98, pp. 649-665, 2010. [5] Le Vine, D.M.; Lagerloef, G.S.E.; Torrusio, S.E.; "Aquarius and Remote Sensing of Sea Surface Salinity from Space," Proceedings of the IEEE , vol.98, no.5, pp.688-703, May 2010, doi: 10.1109/JPROC.2010.2040550.
ERIC Educational Resources Information Center
Foster, Geraldine R. K.; Tickle, Martin
2013-01-01
Background and objective: Some districts in the United Kingdom (UK), where the level of child dental caries is high and water fluoridation has not been possible, implement school-based fluoridated milk (FM) schemes. However, process variables, such as consent to drink FM and loss of children as they mature, impede the effectiveness of these…
Stability Analysis of Active Landslide Region in Gerze (Sinop), NW Turkey
NASA Astrophysics Data System (ADS)
Çellek, S.; Bulut, F.
2009-04-01
Landslides occurring in Turkey causes loss of life and property like many countries of the world. In Turkey, especially Black sea region, landslides are investigated in scale of village, province and city. In this study, Gerze town of Sinop located in Western Black sea was chosen as study area. The study area has some sensitive regions to landslides because of geology, geomorphology and climate conditions. Landslides occur due to heavy rains happen and snow melts in spring time. Recent, landslides occurring in costal areas have effected on choosing the Gerze area. In order to determine the landslides occurring in Gerze, field and laboratory studies have been carried out. 30 sample location was choose as 5 sample per each km2. After determining landslide areas, distributed and undistributed samples were taken for laboratory experiments and clay content. Based on field studies and laboratory experiment, five landslides were determined, called Deniz Feneri, Zenginler Sitesi, Bedre, Mezbahane and Ucuk. These landslides are still active, and their slopes are unstable. So, tension crakes are still seen behind of landslide main mirrors. Of them, The Uçuk landslide has two different secondary slope surfaces and is also reactive landslide. Springs are observed in both slope surface of the Uçuk landslide. The Mezbahane landslide has circular slope plane and tongue shape. The Deniz Feneri and Zenginler Sitesi landslides show different types of, activity and water content so they maybe classified as complex structure. The Deniz Feneri landslide has some tension crack, between 60 cm and 80 cm in depth. The Bedre landslide has half moon shape. GPS measurements in The Deniz Feneri and The Uçuk landslides were calculated to find out safety factors stable5 program according to Janbu and Bishop methods. The safety factors of the Deniz Feneri and The Uçuk landslides are between 0.489 -0.418 and 0.635-0.608, respectively. Since these landslides were affected negatively by Samsun-Sinop highway, load and brook, these negative effects were eliminated and safety factors recalculated. The recalculated safety factors between 0.855-0.889 and 0.976-0.905, respectively. It was determined that water content and loads have effected negatively to these landslides. The study area consists of sedimentary rocks. Most of landslides in study area occurred in weathered soil. Geotechnical properties of the soil samples collected; the specific unit weight 2.60 and 2.80 gr/cm3, water content 15% and 33%, natural unit weight 2.610 and 2.09 gr/cm3, dry unit weight, 1.28 and 1.86 gr/cm3, porosity 29% and 61%. The soil samples contain 27.49% clay, 29.92% silt, 11.08% sand, and 11.33% gravel based on grain size distribution. Soil samples have liquid limit values between 36% and 75% and plasticity index values, between 13% and 45%. The Soil samples for the study area show high and very high plasticity, called solid and very solid. According to USCS most of the soil samples were determined unctuous clay. Clays can be classified normal and non-active and their swelling potential medium-high. Cohesion of soils the samples are between 0.027 and 0.579 kg/cm2, internal friction angels are between 29.5 and 7.53, free compressive strength are between 1.89 and 5.5 kg/ cm2.
Kelly-Gerreyn, Boris A; Hydes, David J; Hartman, Mark C; Siddorn, John; Hyder, Patrick; Holt, Martin W
2007-07-01
This study evaluates the ship of opportunity (Ferrybox) concept for both sustained monitoring of UK shelf sea waters and numerical model validation. Release of phosphate from the wreck of a chemical tanker (MV Ece) in the western English Channel (49.73 degrees N, 3.25 degrees W) in March 2006 is used to demonstrate the importance of sustained observations in decision support systems and policy development. The Ferrybox system continuously collects sea surface (5m) data from a suite of autonomous electronic sensors installed on a passenger ferry operating year-round between Portsmouth (UK) and Bilbao (Spain). The detection of anomalously high concentrations of phosphate (1.54mmolm(-3), four times the usual level) and onset of phytoplankton growth close to the wreck site in March 2006 was placed in the context of multiple years of measurements (phosphate, nitrate, silicate and chlorophyll) collected from the Ferrybox system (2003-2006) and the long-term time series station E1 (50.03 degrees N, 4.65 degrees W, 1930-1987) in the English Channel. With regard to decision support, release of phosphate from the tanker is unlikely to pose a threat as phytoplankton growth at the end of winter is not unusual in this region and dissolved inorganic nitrogen rather than phosphate (DIN:DIP=10-18) is likely to ultimately limit algal growth in spring 2006. With regard to policy development, the Oslo and Paris (OSPAR) commissions recommendation of sampling every three years in "non-problem areas" is likely to provide statistically inadequate data, given the interannual and decadal variability identified in the Ferrybox and E1 data: the Ferrybox data show that oceanic winter nutrient concentrations varied by 35-50% between 2003/2004 and 2005/2006 due to deeper mixing of water off-shelf in early 2005/2006 and comparisons between the Ferrybox and E1 years show that the western English Channel is currently experiencing a low in phosphate concentrations similar to those in the 1960s. The importance of Ferrybox data in evaluating the reliability of predictive operational models needed in decision support is also demonstrated, by highlighting both strengths and weaknesses in a state-of-the-art ecosystem model designed for UK shelf waters.
Full 2D observation of water surface elevation from SWOT under different flow conditions
NASA Astrophysics Data System (ADS)
Domeneghetti, Alessio; Schumann, Guy; Rui, Wei; Durand, Michael; Pavelsky, Tamlin
2016-04-01
The upcoming Surface Water and Ocean Topography (SWOT) satellite mission is a joint project of NASA, Centre National d'Etudes Spatiales (CNES, France), the Canadian Space Agency, and the Space Agency of the UK that will provide a first global, high-resolution observation of ocean and terrestrial water surface heights. Characterized by an observation swath of 120 km and an orbit repeat interval of about 21 days, SWOT will provide unprecedented bi-dimensional observations of rivers wider than 50-100 m. Despite many research activities that have investigated potential uses of remotely sensed data from SWOT, potentials and limitations of the spatial observations provided by the satellite mission for flood modeling still remain poorly understood and investigated. In this study we present a first analysis of the spatial observation of water surface elevation that is expected from SWOT for a 140 km reach of the middle-lower portion of the Po River, in Northern Italy. The river stretch is characterized by a main channel varying from 200-500 m in width and a floodplain that can be as wide as 5 km and that is delimited by a system of major embankments. The reconstruction of the hydraulic behavior of the Po River is performed by means of a quasi-2d model built with detailed topographic and bathymetric information (LiDAR, 2 m resolution), while the simulation of the spatial observation sensed by SWOT is performed with a SWOT simulator that mimics the satellite sensor characteristics. Referring to water surface elevations associated with different flow conditions (maximum, minimum and average flow reproduced by means of the quasi-2d numerical model) this work provides a first characterization of the spatial observations provided by SWOT and highlights the strengths and limitations of the expected products. By referring to a real river reach the analysis provides a credible example of the type of spatial observations that will be available after launch of SWOT and offers a first evaluation of the possible effects of river embankments, river width and river topography under different hydraulic conditions. Results of the study characterize the expected accuracy of the upcoming SWOT mission and provide additional insights towards more appropriate exploitation of future potential hydrologic data.
How Unusual Was The Storm Surge Season Of 2013-14 in the UK?
NASA Astrophysics Data System (ADS)
Haigh, I. D.; Wadey, M.; Gallop, S. L.; Nicholls, R. J.; Horsburgh, K.
2014-12-01
When significant coastal flooding occurs along low-lying, highly populated, and/or developed coastlines, the impacts can be devastating and long lasting with wide ranging social, economic, and environmental consequences. The UK has a long history of severe coastal flooding, with major events including those that occurred in 1607, 1703 and 1953. The problems associated with coastal flooding again reached the forefront during the latest winter of 2013-2014 when the UK experienced a series of very severe events. What is noteworthy about this most recent winter period is the: (1) large number of significantly coastal flooding events occurring one after another over a relatively short period of time; and (2) the large areas of coastline affected. Extreme events are rarely assessed in terms of 'clustering', despite the fact this leads to amplified flood damages. The spatial dependence in flood hazard (i.e. simultaneous flooding in multiple locations) is now receiving more attention, motivated by concern from re-insurance, infrastructure reliability and emergency response, but understanding in this area is still limited. In this paper we assess extreme high water events and their temporal clustering and footprint around the UK, using records from the UK national network of 40 tide gauges, the longest of which extends back 100 years. We identify 100 distinct events, during which water levels exceeded the 1 in 5 year return period. We examine these events in detail and assess the coastal flooding that occurred during each event.
NASA Astrophysics Data System (ADS)
Plancq, Julien; Grossi, Vincent; Huguet, Carme; Pittet, Bernard; Rosell-Mele, Antoni; Mattioli, Emanuela
2014-05-01
The late Pliocene (Piacenzian; 3.6-2.6 Myr) in the Mediterranean region is characterized by the deposition of organic-rich sedimentary layers named sapropels. Sapropel formation has been related to the strengthening of the precessionally-controlled African monsoon, triggering enhanced primary productivity and/or improved organic matter preservation. However, the relative importance of surface-ocean productivity versus deep-water preservation for sapropel formation remains a long standing debate among the science community. Here, we used a multi-proxy approach to characterize long-term environmental conditions and to discuss sapropel formation during the late Pliocene at Punta Grande/Punta Piccola sections (southwest Sicily). Sea and air temperatures were reconstructed using all the lipid biomarker-based temperature proxies currently available: the alkenone unsaturation index (UK'37), the tetraether index (TEX86), the Long-chain Diol Index (LDI), and the degree of methylation/cyclization of branched tetraether (MBT/CBT). Results show that sea-surface temperatures (SSTs) were relatively stable throughout the late Pliocene, but that consistent increases are recorded in most sapropel layers. SST record was then compared with variations in total organic carbon proportions, lipid biomarkers contents and nannofossil assemblages. Based on these observations, two mechanisms of formation can be inferred for each sapropel. A first series of sapropels is likely due to a better preservation of organic matter, due to the development of a thermohaline stratification of the water column and to oxygen depleted bottom waters. The second series of sapropels is more likely due to enhanced primary productivity in a non-stratified water column.
How important is drinking water exposure for the risks of engineered nanoparticles to consumers?
Tiede, Karen; Hanssen, Steffen Foss; Westerhoff, Paul; Fern, Gordon J; Hankin, Steven M; Aitken, Robert J; Chaudhry, Qasim; Boxall, Alistair B A
2016-01-01
This study explored the potential for engineered nanoparticles (ENPs) to contaminate the UK drinking water supplies and established the significance of the drinking water exposure route compared to other routes of human exposure. A review of the occurrence and quantities of ENPs in different product types on the UK market as well as release scenarios, their possible fate and behaviour in raw water and during drinking water treatment was performed. Based on the available data, all the ENPs which are likely to reach water sources were identified and categorized. Worst case concentrations of ENPs in raw water and treated drinking water, using a simple exposure model, were estimated and then qualitatively compared to available estimates for human exposure through other routes. A range of metal, metal oxide and organic-based ENPs were identified that have the potential to contaminate drinking waters. Worst case predicted concentrations in drinking waters were in the low- to sub-µg/l range and more realistic estimates were tens of ng/l or less. For the majority of product types, human exposure via drinking water was predicted to be less important than exposure via other routes. The exceptions were some clothing materials, paints and coatings and cleaning products containing Ag, Al, TiO2, Fe2O3 ENPs and carbon-based materials.
NASA Astrophysics Data System (ADS)
Vieno, M.; Heal, M. R.; Hallsworth, S.; Famulari, D.; Doherty, R. M.; Dore, A. J.; Tang, Y. S.; Braban, C. F.; Leaver, D.; Sutton, M. A.; Reis, S.
2014-08-01
Surface concentrations of secondary inorganic particle components over the UK have been analysed for 2001-2010 using the EMEP4UK regional atmospheric chemistry transport model and evaluated against measurements. Gas/particle partitioning in the EMEP4UK model simulations used a bulk approach, which may lead to uncertainties in simulated secondary inorganic aerosol. However, model simulations were able to accurately represent both the long-term decadal surface concentrations of particle sulfate and nitrate and an episode in early 2003 of substantially elevated nitrate measured across the UK by the AGANet network. The latter was identified as consisting of three separate episodes, each of less than 1 month duration, in February, March and April. The primary cause of the elevated nitrate levels across the UK was meteorological: a persistent high-pressure system, whose varying location impacted the relative importance of transboundary versus domestic emissions. Whilst long-range transport dominated the elevated nitrate in February, in contrast it was domestic emissions that mainly contributed to the March episode, and for the April episode both domestic emissions and long-range transport contributed. A prolonged episode such as the one in early 2003 can have substantial impact on annual average concentrations. The episode led to annual concentration differences at the regional scale of similar magnitude to those driven by long-term changes in precursor emissions over the full decade investigated here. The results demonstrate that a substantial part of the UK, particularly the south and southeast, may be close to or exceeding annual mean limit values because of import of inorganic aerosol components from continental Europe under specific conditions. The results reinforce the importance of employing multiple year simulations in the assessment of emissions reduction scenarios on particulate matter concentrations and the need for international agreements to address the transboundary component of air pollution.
NASA Astrophysics Data System (ADS)
SHI, J.
2014-12-01
Climate change is expected to have a significant impact on flooding in the UK, inducing more intense and prolonged storms. Frequent flooding due to climate change already exacerbates catchment water quality. Land use is another contributing factor to poor water quality. For example, the move to intensive farming could cause an increase in faecal coliforms entering the water courses. In an effort to understand better the effects on water quality from land use and climate change, the hydrological and estuarine processes are being modelled using SWAT (Soil and Water Assessment Tool), linked to a 2-D hydrodynamic model DIVAST(Depth Integrated Velocity and Solute Transport). The coupled model is able to quantify how much of each pollutant from the catchment reaches the harbour and the impact on water quality within the harbour. The work is focused on the transportation and decay of faecal coliforms from agricultural runoff into the rivers Frome and Piddle in the UK. The impact from the agricultural land use and activities on the catchment river hydrology and water quality are evaluated. The coupled model calibration and validation showed the good model performance on flow and faecal coliform in the watershed and estuary.
Middleton, D R S; Watts, M J; Hamilton, E M; Ander, E L; Close, R M; Exley, K S; Crabbe, H; Leonardi, G S; Fletcher, T; Polya, D A
2016-05-09
Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 μg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 μg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman's ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-As(IMM), of urinary inorganic As species, arsenite (As(III)) and arsenate (As(V)), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman's ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users.
Middleton, D. R. S.; Watts, M. J.; Hamilton, E. M.; Ander, E. L.; Close, R. M.; Exley, K. S.; Crabbe, H.; Leonardi, G. S.; Fletcher, T.; Polya, D. A.
2016-01-01
Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 μg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 μg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman’s ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-AsIMM, of urinary inorganic As species, arsenite (AsIII) and arsenate (AsV), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman’s ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users. PMID:27156998
NASA Astrophysics Data System (ADS)
Middleton, D. R. S.; Watts, M. J.; Hamilton, E. M.; Ander, E. L.; Close, R. M.; Exley, K. S.; Crabbe, H.; Leonardi, G. S.; Fletcher, T.; Polya, D. A.
2016-05-01
Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 μg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 μg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman’s ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-AsIMM, of urinary inorganic As species, arsenite (AsIII) and arsenate (AsV), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman’s ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users.
NASA Astrophysics Data System (ADS)
Guillod, B. P.; Massey, N.; Otto, F. E. L.; Allen, M. R.; Jones, R.; Hall, J. W.
2016-12-01
Extreme events being rare by definition, accurately quantifying the probabilities associated with a given event is difficult. This is particularly true for droughts, for which only few events are available in the observational record owing to their long-lasting characteristics. The MaRIUS project (Managing the Risks, Impacts and Uncertainties of drought and water Scarcity) aims at quantifying present and future risks associated with droughts in the UK. To do so, a large number of modelled weather time series for "synthetic" drought events are being fed into hydrological and impact models to assess their impacts on various sectors (social sciences, economy, industry, agriculture, and ecosystems). Here, we present and analyse the hydro-meteorological drought event sets that have been produced with a new version of weather@home [1] for MaRIUS. Using idle processor time on volunteers' computers around the world, we have run a very large number (10'000s) of Global Climate Model simulations, downscaled at 25km over Europe by a nested Regional Climate Model. Simulations include the past 100 years as well as two future time slices (2030s and 2080s), and provide a large number of sequences of spatio-temporally coherent weather, which are consistent with the boundary forcing such as the ocean, greenhouse gases and solar forcing. Beside presenting the methodology and validation of the event sets, we provide insights into drought risk in the UK and the drivers of drought. In particular, we examine their sensitivity to sea surface temperature and sea ice patterns, both in the recent past and for future projections. How drought risk in the UK can be expected to change in the future will also be discussed. Finally, we assess the applicability of this methodology to other regions. Reference: [1] Massey, N. et al., 2014, Q. J. R. Meteorol. Soc.
Mitchell, Neil C
2012-12-13
Much progress has been made in the UK in characterizing the internal structures of major physiographic features in the oceans and in developing understanding of the geological processes that have created or shaped them. UK researchers have authored articles of high impact in all areas described here. In contrast to terrestrial geoscience, however, there have been few instrumented observations made of active processes by UK scientists. This is an area that could be developed over the next decades in the UK. Research on active processes has the potential ability to engage the wider public: Some active processes present significant geo-hazards to populations and offshore infrastructure that require monitoring and there could be commercial applications of technological developments needed for science. Some of the suggestions could involve studies in shallow coastal waters where ship costs are much reduced, addressing tighter funding constraints over the near term. The possibilities of measuring aspects of volcanic eruptions, flowing lava, turbidity currents and mass movements (landslides) are discussed. A further area of potential development is in greater collaboration between the ocean sciences. For example, it is well known in terrestrial geomorphology that biological agents are important in modulating erosion and the transport of sediments, ultimately affecting the shape of the Earth's surface in various ways. The analogous effect of biology on large-scale geomorphology in the oceans is also known but remains poorly quantified. Physical oceanographic models are becoming increasingly accurate and could be used to study further the patterns of erosion, particle transport and deposition in the oceans. Marine geological and geophysical data could in turn be useful for further verification of such models. Adapting them to conditions of past oceans could address the shorter-period movements, such as due to internal waves and tides, which have been barely addressed in palaeoceanography.
NASA Astrophysics Data System (ADS)
George, S. E.; Herbert, T.; Amaral-Zettler, L. A.; Richter, N.
2017-12-01
Long chain polyunsaturated alkenone (LCA) lipid biomarkers produced by haptophyte phytoplankton species within the Order Isochrysidales (Phylum Haptophyta) have proven exceptionally useful in paleotemperature studies by means of the Uk'37 and Uk37 indices. Two closely-related Group III haptophytes, Emiliania huxleyi and Gephyrocapsa oceanica are the primary alkenone synthesizers in the modern ocean, while freshwater systems host the distinct Group I phylotype, sometimes called the Greenland phylotype, in reference to the location of its original discovery. Group I haptophytes produce large quantities of the distinct C37:4 ketone, which acts as a chemical `fingerprint' in sediments. The utility of alkenones as a paleotemperature proxy in estuarine environments has remained largely untested, representing an under-utilized opportunity to construct high-resolution paleotemperature records from environments at the intersection of fluvial and marine systems. This uncertainty is due, in part, to the presence of multiple haptophyte groups in estuaries, resulting in a mixed alkenone signature. To determine the community composition of alkenone-producing haptophytes within Narragansett Bay, four geographically separated cores from within the Bay were analyzed for alkenones as well as haptophyte rRNA biomarker gene presence. Haptophyte rRNA genes (small and large subunit) were recovered from surface and near-subsurface samples, and in conjunction with alkenone profiles, reveal recent haptophyte community structure and alkenone production regimes throughout the Bay. A surprising result is the recovery of rRNA biomarker genes with a 100% match to the open-ocean alkenone producer E. huxleyi in locations away from large fresh water inputs to the Bay. Results of these analyses elucidate the effect of salinity and nutrient dynamics on alkenone-producing haptophyte communities and enhance applicability of long chain polyunsaturated alkenones as lipid biomarkers in estuarine environments. Future work will enhance Uk'37 analyses of Narragansett Bay sediments to better resolve historically and climatically significant events in the region, such as European settlement, the Industrial Revolution, and 20th century warming and eutrophication.
Engineering Extreme Hydrophobic and Super Slippery Water Shedding Surfaces
NASA Astrophysics Data System (ADS)
McHale, Glen
2017-04-01
The intrinsic water repellency of a material is fundamentally determined by its surface chemistry, but alone this does not determine the ability of a surface to shed water. Physical factors such as the surface texture/topography, rigidity/flexibility, granularity/porosity combined with the intrinsic wetting properties of the liquid with the surface and whether it is infused by a lubricating liquid are equally important. In this talk I will outline fundamental, but simple, ideas on the topographic enhancement of surface chemistry to create superhydrophobicity, the adhesion of particles to liquid-air interfaces to create liquid marbles, elastocapillarity to create droplet wrapping, and lubricant impregnated surfaces to create completely mobile droplets [1-3]. I will discuss how these ideas have their origins in natural systems and surfaces, such as Lotus leaves, galling aphids and the Nepenthes pitcher plant. I will show how we have applied these concepts to study the wetting of granular systems, such as sand, to understand extreme soil water repellency. I will argue that relaxing the assumption that a solid substrate is fixed in shape and arrangement, can lead to the formation of liquid marbles, whereby a droplet self-coats in a hydrophobic powder/grains. I will show that the concepts of wetting and porosity blur as liquids penetrate into a porous or granular substrate. I will also discuss how lubricant impregnated super slippery surfaces can be used to study a pure constant contact angle mode of droplet evaporation [4]. Finally, I will show dewetting of a surface is not simply a video reversal of wetting [5], and I will give an example of the use of perfect hydrophobicity using the Leidenfrost effect to create a new type of low friction mechanical and hear engine [6]. References: [1] Shirtcliffe, N. J., et al., An introduction to superhydrophobicity. Advances in Colloid and Interface Science, vol. 161, pp.124-138 (2010). [2] McHale, G. & Newton, M. I. Liquid marbles: topical context within soft matter and recent progress. Soft Matter, vol. 11, pp. 2530-2546 (2015). [3] Geraldi, N. R., et al., Capillary origami and superhydrophobic membrane surfaces. Applied Physics Letters, vol. 102, art. 214104 (2013). [4] Guan, J. H. et al., Evaporation of sessile droplets on Slippery Liquid-Infused Porous Surfaces (SLIPS). Langmuir, vol. 31, pp. 11781-11789 (2015). [5] Edwards, A. M. J., et al., Not spreading in reverse: The dewetting of a liquid film into a single drop. Science Advances, vol. 2, art. e1600183-e1600183 (2016). [6] Wells, G. G., et al., A sublimation heat engine. Nature Communications, vol. 6, art. 6390 (2015). Acknowledgement: This work has been financially supported by the UK EPSRC and Reece Innovation Ltd, and developed in collaboration with co-workers at Northumbria, Nottingham Trent, Edinburgh, Swansea and Durham Universities.
Wetland methane modelling over the Scandinavian Arctic: Performance of current land-surface models
NASA Astrophysics Data System (ADS)
Hayman, Garry; Quiquet, Aurélien; Gedney, Nicola; Clark, Douglas; Friend, Andrew; George, Charles; Prigent, Catherine
2014-05-01
Wetlands are generally accepted as being the largest, but least well quantified, single natural source of CH4, with global emission estimates ranging from 100-231 Tg yr-1 [1] and for which the Boreal and Arctic regions make a significant contribution [2, 3]. The recent review by Melton et al. [4] has provided a summary of the current state of knowledge on the modelling of wetlands and the outcome of the WETCHIMP model intercomparison exercise. Melton et al. found a large variation in the wetland areas and associated methane emissions from the participating models and varying responses to climate change. In this paper, we report results from offline runs of two land surface models over Scandinavia (JULES, the Joint UK Land Environment Simulator [5, 6] and HYBRID8 [7]), using the same driving meteorological dataset (CRU-NCEP) for the period from January 1980 to December 2010. Although the two land surface models are very different, both models have used a TOPMODEL approach to derive the wetland area and have similar parameterisations of the methane wetland emissions. We find that both models give broadly similar results. They underestimate the wetland areas over Northern Scandinavia, compared to remote sensing and map-based datasets of wetlands [8]. This leads to lower predicted methane emissions compared to those observed on the ground and from aircraft [9]. We will present these findings and identify possible reasons for the underprediction. We will show the sensitivity to using the observed wetland areas to improve the methane emission estimates. References [1] Denman, K., et al.,: Couplings Between Changes in the Climate System and Biogeochemistry, In Climate Change 2007: The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, United Kingdom, 2007; [2] Smith, L. C., et al.: Siberian peatlands a net carbon sink and global methane source since the early Holocene, Science, 303, 353-356, doi:10.1126/science.1090553, 2004; [3] Zhuang, Q., et al.: CO2 and CH4 exchanges between land ecosystems and the atmosphere in northern high latitudes over the 21st century, Geophysical Research Letters, 33, doi:10.1029/2006gl026972, 2006; [4] Melton, J.R., et al.: Present state of global wetland extent and wetland methane modelling: conclusions from a model inter-comparison project (WETCHIMP), Biogeosciences, 10, 753-788, doi:10.5194/bg-10-753-2013, 2013; [5] Best, M. J., et al.: The Joint UK Land Environment Simulator (JULES), model description - Part 1: Energy and water fluxes, Geoscientific Model Development, 4, 677-699, doi:10.5194/gmd-4-677-2011, 2011; [6] Clark, D.B., et al.: The Joint UK Land Environment Simulator (JULES), Model description - Part 2: Carbon fluxes and vegetation. Geoscientific Model Development, 4, 701-722, doi:10.5194/gmd-4-701-2011, 2011; [7] Friend, A.D., and N.Y. Kiang: Land surface model development for the GISS GCM: Effects of improved canopy physiology on simulated climate. J. Climate, 18, 2883-2902, doi:10.1175/JCLI3425.1, 2005; [8] Prigent, C., et al.: Changes in land surface water dynamics since the 1990s and relation to population pressure, Geophys. Res. Lett., 39, L08403, doi:10.1029/2012GL051276, 2012; [9] O'Shea, S., et al.: Methane and carbon dioxide fluxes from the European Arctic wetlands during the MAMM project, paper in preparation.
NASA Astrophysics Data System (ADS)
Outram, F. N.; Lloyd, C.; Jonczyk, J.; Benskin, C. McW. H.; Grant, F.; Dorling, S. R.; Steele, C. J.; Collins, A. L.; Freer, J.; Haygarth, P. M.; Hiscock, K. M.; Johnes, P. J.; Lovett, A. L.
2013-12-01
The Demonstration Test Catchments (DTC) project is a UK Government funded initiative to test the effectiveness of on-farm mitigation measures designed to reduce agricultural pollution without compromising farm productivity. Three distinct catchments in England have been chosen to test the efficacy of mitigation measures on working farms in small tributary sub-catchments equipped with continuous water quality monitoring stations. The Hampshire Avon in the south is a mixed livestock and arable farming catchment, the River Wensum in the east is a lowland catchment with predominantly arable farming and land use in the River Eden catchment in the north-west is predominantly livestock farming. One of the many strengths of the DTC as a national research platform is that it provides the ability to investigate catchment hydrology and biogeochemical response across different landscapes and geoclimatic characteristics, with a range of differing flow behaviours, geochemistries and nutrient chemistries. Although numerous authors present studies of individual catchment responses to storms, no studies exist of multiple catchment responses to the same rainfall event captured with in situ high-resolution nutrient monitoring at a national scale. This paper brings together findings from all three DTC research groups to compare the response of the catchments to a major storm event in April 2012. This was one of the first weather fronts to track across the country following a prolonged drought period affecting much of the UK through 2011-2012, marking an unusual meteorological transition when a rapid shift from drought to flood risk occurred. The effects of the weather front on discharge and water chemistry parameters, including nitrogen species (NO3-N and NH4-N) and phosphorus fractions (total P (TP) and total reactive P (TRP)), measured at a half-hourly time step are examined. When considered in the context of one hydrological year, flow and concentration duration curves reveal that the weather fronts resulted in extreme flow, nitrate and TP concentrations in all three catchments but with distinct differences in both hydrographs and chemographs. Hysteresis loops constructed from high resolution data are used to highlight an array of potential pollutant sources and delivery pathways. In the Hampshire Avon DTC, transport was dominated by sub-surface processes, where phosphorus, largely in the soluble form, was found to be transport-limited. In the Wensum DTC, transport was largely dominated by rapid sub-surface movement due to the presence of under-drainage, which mobilised large quantities of nitrate during the storm. In the Eden DTC, transport was found to be initially dominated by surface runoff, which switched to subsurface delivery on the falling limb of the hydrograph, with the surface delivery transporting large amounts of particulate phosphorus to the river, with a transport-limited response. The lack of exhaustion of nutrient delivery in response to such extreme flow generation indicates the size of the nutrient pools stored in these catchments, and highlights the scale of the challenges faced by environmental managers when designing mitigation measures to reduce the flux of nutrients to UK river systems from diffuse agricultural sources.
NASA Astrophysics Data System (ADS)
Egea, G.; Verhoef, A.; Vidale, P. L.; Black, E.; Van den Hoof, C.
2012-04-01
Coupled photosynthesis-stomatal conductance (A-gs) models are commonly used in ecosystem models to represent the exchange rate of CO2 and H2O between vegetation and the atmosphere. The ways these models account for water stress differ greatly among modelling schemes. This study provides insight into the impact of contrasting model configurations of water stress on the simulated leaf-level values of net photosynthesis (A), stomatal conductance (gs), the functional relationship among them and their ratio, the intrinsic water use efficiency (A/gs), as soil dries. A simple, yet versatile, normalized soil moisture dependent function was used to account for the effects of water stress on gs, on mesophyll conductance (gm ) and on the biochemical capacity (Egea et al., 2011). Model output was compared to leaf-level values obtained from the literature. The sensitivity analyses emphasized the necessity to combine both stomatal and non-stomatal limitations of A in coupled A-gs models to accurately capture the observed functional relationships A vs. gs and A/gs vs. gs in response to drought. Accounting for water stress in coupled A-gs models by imposing either stomatal or biochemical limitations of A, as commonly practiced in most ecosystem models, failed to reproduce the observed functional relationship between key leaf gas exchange attributes. A quantitative limitation analysis revealed that the general pattern of C3 photosynthetic response to water stress can be represented in coupled A-gs models by imposing the highest limitation strength to mesophyll conductance, then to stomatal conductance and finally to the biochemical capacity. This more realistic representation of soil water stress on the simulated leaf-level values of A and gs was embedded in the JULES (Joint UK Land Environment Simulator; Best et al., 2011), model and tested for a number of vegetation types, for which driving and flux verification data were available. These simulations provide an insight into the effect that the revised parameterization will have on GCM simulations of climate variability and change. Best, M. J. et al. (2011). The Joint UK Land Environment Simulator (JULES), model description - Part 1: Energy and water fluxes. Geosci. Model Dev., 4, 677-699. Egea, G., Verhoef, A., Vidale, P.L. (2011) Towards an improved and more flexible representation of water stress in coupled photosynthesis-stomatal conductance models. Agricultural and Forest Meteorology, 151 (10), 1370-1384.
Anthropogenic 129I in the North Pacific, Bering and Chukchi Seas, and Arctic Ocean in 2012-2013
NASA Astrophysics Data System (ADS)
Nagai, H.; Hasegawa, A.; Yamagata, T.; Kumamoto, Y.; Nishino, S.; Matsuzaki, H.
2015-10-01
Most of anthropogenic 129I in marine environment are due to discharge from the nuclear fuel reprocessing facilities at Sellafield (U.K.) and La Hague (France) for past few decades. The discharge raised 129I concentration in seawaters in the North Atlantic and Arctic Oceans to more than 109 atoms L-1, which is two orders of magnitude higher than that in other region. Recently, in March 2011, a large quantity of 129I was released into the western North Pacific due to the Fukushima Daiichi Nuclear Power Plant (F1NPP) accident. To evaluate the influence of these events, we have measured 129I concentration in seawaters in the northern North Pacific Ocean, Bering and Chukchi Seas, and Arctic Ocean in 2012-2013. The 129I concentrations were 1.0-1.8 × 107 atoms L-1 in the surface waters in the vicinity of 47°N 150°E-130°W North Pacific Ocean, Bering Sea, and Chukchi Sea (<74°N), which are equal to or lower than the 129I concentration level in surface water in the North Pacific Ocean before the F1NPP accident. The vertical profiles in the North Pacific were almost same as that observed in the western North Pacific before the F1NPP accident. The 129I distribution in seawater in the North Pacific to the Chukchi Sea revealed no significant increase of 129I concentration caused by the F1NPP accident. The 129I concentrations were 13-14 × 107 atoms L-1 in surface waters and 80 × 107 atoms L-1 at depths of 300 and 800 m in the Arctic Ocean.
Developing a Global Network of River Reaches in Preparation of SWOT
NASA Astrophysics Data System (ADS)
Lion, C.; Pavelsky, T.; Allen, G. H.; Beighley, E.; Schumann, G.; Durand, M. T.
2016-12-01
In 2020, the Surface Water and Ocean Topography satellite (SWOT), a joint mission of NASA/CNES/CSA/UK will be launched. One of its major products will be the measurements of continental water surfaces, including the width, height, and slope of rivers and the surface area and elevations of lakes. The mission will improve the monitoring of continental water and also our understanding of the interactions between different hydrologic reservoirs. For rivers, SWOT measurements of slope will be carried out over predefined river reaches. As such, an a priori dataset for rivers is needed in order to facilitate analysis of the raw SWOT data. The information required to produce this dataset includes measurements of river width, elevation, slope, planform, river network topology, and flow accumulation. To produce this product, we have linked two existing global datasets: the Global River Widths from Landsat (GRWL) database, which contains river centerline locations, widths, and a braiding index derived from Landsat imagery, and a modified version of the HydroSHEDS hydrologically corrected digital elevation product, which contains heights and flow accumulation measurements for streams at 3 arcseconds spatial resolution. Merging these two datasets requires considerable care. The difficulties, among others, lie in the difference of resolution: 30m versus 3 arseconds, and the age of the datasets: 2000 versus 2010 (some rivers have moved, the braided sections are different). As such, we have developed custom software to merge the two datasets, taking into account the spatial proximity of river channels in the two datasets and ensuring that flow accumulation in the final dataset always increases downstream. Here, we present our results for the globe.
NASA Astrophysics Data System (ADS)
Clark, D. B.; Mercado, L. M.; Sitch, S.; Jones, C. D.; Gedney, N.; Best, M. J.; Pryor, M.; Rooney, G. G.; Essery, R. L. H.; Blyth, E.; Boucher, O.; Harding, R. J.; Cox, P. M.
2011-03-01
The Joint UK Land Environment Simulator (JULES) is a process-based model that simulates the fluxes of carbon, water, energy and momentum between the land surface and the atmosphere. Past studies with JULES have demonstrated the important role of the land surface in the Earth System. Different versions of JULES have been employed to quantify the effects on the land carbon sink of separately changing atmospheric aerosols and tropospheric ozone, and the response of methane emissions from wetlands to climate change. There was a need to consolidate these and other advances into a single model code so as to be able to study interactions in a consistent manner. This paper describes the consolidation of these advances into the modelling of carbon fluxes and stores, in the vegetation and soil, in version 2.2 of JULES. Features include a multi-layer canopy scheme for light interception, including a sunfleck penetration scheme, a coupled scheme of leaf photosynthesis and stomatal conductance, representation of the effects of ozone on leaf physiology, and a description of methane emissions from wetlands. JULES represents the carbon allocation, growth and population dynamics of five plant functional types. The turnover of carbon from living plant tissues is fed into a 4-pool soil carbon model. The process-based descriptions of key ecological processes and trace gas fluxes in JULES mean that this community model is well-suited for use in carbon cycle, climate change and impacts studies, either in standalone mode or as the land component of a coupled Earth system model.
Review of Offshore Wind Farm Impact Monitoring and Mitigation with Regard to Marine Mammals.
Verfuss, Ursula K; Sparling, Carol E; Arnot, Charlie; Judd, Adrian; Coyle, Michael
2016-01-01
Monitoring and mitigation reports from 19 UK and 9 other European Union (EU) offshore wind farm (OWF) developments were reviewed, providing a synthesis of the evidence associated with the observed environmental impact on marine mammals. UK licensing conditions were largely concerned with mitigation measures reducing the risk of physical and auditory injury from pile driving. At the other EU sites, impact monitoring was conducted along with mitigation measures. Noise-mitigation measures were developed and tested in UK and German waters in German government-financed projects. We highlight some of the review's findings and lessons learned with regard to noise impact on marine mammals.
Steen-Olsen, Kjartan; Weinzettel, Jan; Cranston, Gemma; Ercin, A Ertug; Hertwich, Edgar G
2012-10-16
A nation's consumption of goods and services causes various environmental pressures all over the world due to international trade. We use a multiregional input-output model to assess three kinds of environmental footprints for the member states of the European Union. Footprints are indicators that take the consumer responsibility approach to account for the total direct and indirect effects of a product or consumption activity. We quantify the total environmental pressures (greenhouse gas emissions: carbon footprint; appropriation of biologically productive land and water area: land footprint; and freshwater consumption: water footprint) caused by consumption in the EU. We find that the consumption activities by an average EU citizen in 2004 led to 13.3 tCO(2)e of induced greenhouse gas emissions, appropriation of 2.53 gha (hectares of land with global-average biological productivity), and consumption of 179 m(3) of blue water (ground and surface water). By comparison, the global averages were 5.7 tCO(2)e, 1.23 gha, and 163 m(3) blue water, respectively. Overall, the EU displaced all three types of environmental pressures to the rest of the world, through imports of products with embodied pressures. Looking at intra-EU displacements only, the UK was the most important displacer overall, while the largest net exporters of embodied environmental pressures were Poland (greenhouse gases), France (land), and Spain (freshwater).
Ethanol effects on the fate and transport of gasoline constituents in the UK.
Firth, Simon; Hildenbrand, Beate; Morgan, Phil
2014-07-01
In the UK, use of ethanol in fuel as a fuel oxygenate/fuel supplement is currently limited but could rise in an effort to meet the requirements of the European "Biofuels" Directive. This Energy Institute study focussed on the risk that accidental releases of ethanol blended gasoline (EBG) (i.e. gasoline containing 10% or less of ethanol) could pose to UK groundwater resources. Ethanol is miscible and highly biodegradable. As a result it tends to be strongly attenuated in the unsaturated zone and in groundwater and so does not, in itself, pose a significant risk to groundwater resources. However, it may lead to increased persistence of other gasoline constituents, particularly through alteration of geochemical conditions as a result of intensive biodegradation activity. A semi-probabilistic modelling exercise was undertaken to better understand the risks that use of EBG could pose to UK groundwater resources. Site investigation information from over 500 filling stations was used in combination with GIS data to predict the proportion of potable water supply wells that could potentially be impacted by benzene and MtBE, and estimate the length of benzene and MtBE plumes with and without the use of ethanol in gasoline. The results show that the use of EBG is likely to have a negligible effect on MtBE plumes. Some increase in benzene plume length is predicted, most notably in fissured aquifers, but increases in plume length of greater than 30% are predicted to be rare. A corresponding slight increase in risk to licensed potable water supply wells from benzene was predicted with the use of EBG but the percentage of wells at risk was still predicted to be small (0.13%), and in the context of the conservatism within the modelling, it was concluded that widespread use of EBG is unlikely to cause an increased risk to UK water resources. Copyright © 2014 Elsevier B.V. All rights reserved.
Food waste disposal units in UK households: the need for policy intervention.
Iacovidou, Eleni; Ohandja, Dieudonne-Guy; Voulvoulis, Nikolaos
2012-04-15
The EU Landfill Directive requires Member States to reduce the amount of biodegradable waste disposed of to landfill. This has been a key driver for the establishment of new waste management options, particularly in the UK, which in the past relied heavily on landfill for the disposal of municipal solid waste (MSW). MSW in the UK is managed by Local Authorities, some of which in a less conventional way have been encouraging the installation and use of household food waste disposal units (FWDs) as an option to divert food waste from landfill. This study aimed to evaluate the additional burden to water industry operations in the UK associated with this option, compared with the benefits and related savings from the subsequent reductions in MSW collection and disposal. A simple economic analysis was undertaken for different FWD uptake scenarios, using the Anglian Region as a case study. Results demonstrated that the significant savings from waste collection arising from a large-scale uptake of FWDs would outweigh the costs associated with the impacts to the water industry. However, in the case of a low uptake, such savings would not be enough to cover the increased costs associated with the wastewater provision. As a result, this study highlights the need for policy intervention in terms of regulating the use of FWDs, either promoting them as an alternative to landfill to increase savings from waste management, or banning them as a threat to wastewater operations to reduce potential costs to the water industry. Copyright © 2012 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Price, Gregory; Grimes, Stephen
2015-04-01
The stable oxygen isotope ratio of chicken eggshell carbonate was analysed from chicken eggs laid under free range, and organic farming regimes from across the UK. The eggshell carbonate oxygen isotope data shows a clear depletion in delta18O distribution from the southwest to the northeast. Although consistently offset by around 1 permil, the same isotopic distribution as that seen in eggshell carbonate is observed in the delta18O ratio of rainfall and groundwater from across the UK. This distribution is related to the Rayleigh distillation of rainfall driven by westerly winds across the UK landmass. The clear relationship observed between eggshell delta18O values and that of rainwater presumably reflects the nature of free range chickens which must be drinking locally derived rainwater and supplementing their diet and water intake with locally derived food. These results suggest that the oxygen isotope value of chicken eggshells can be used as a forensic tool to identify the locality that free range and organic eggs were laid within the UK. Furthermore, if suitable material is preserved in the archaeological and geological record then such a relationship can potentially be used to establish the oxygen isotope value of rainwater from which ancient and / or ancestral birds lived.
The prospects for solar energy use in industry within the United Kingdom
NASA Astrophysics Data System (ADS)
Lewis, C. W.
1980-01-01
An assessment of the potential for solar energy applications within U.K. industry has been made, using a disaggregated breakdown of energy consumption in the eight industrial sectors by fuel and end-use, and taking account of solar collector performance under U.K. climatic conditions. Solar contributions of 35 per cent of process boiler heat up to a temperature of 80 C and 10 per cent in the 80-120 C range are considered feasible, along with 35 per cent of non-industrial water heating. After employing energy conservation techniques currently more cost-effective than solar systems, an additional 3.5 per cent of U.K. primary energy expended in manufacturing industry (excluding iron and steel production) could be contributed by solar. This represents 1 per cent of the U.K. national primary energy demand.
Carbon loading of alveolar macrophages in adults and children exposed to biomass smoke particles.
Kulkarni, Neeta S; Prudon, Benjamin; Panditi, Sri L; Abebe, Yekoye; Grigg, Jonathan
2005-06-01
Exposure to carbonaceous particles from biomass burning is associated with increased respiratory morbidity in both women and children in the developing world. However, the amount of carbon reaching lower airway cells has not been determined in these populations. Alveolar macrophages (AM) remove inhaled particulate matter (PM), and are implicated in the pathogenesis of PM-induced lung disease. In this study, we aimed to compare AM carbon loading in women and children exposed to biomass PM in Gondar, Ethiopia, with individuals exposed to fossil-fuel PM in the developed world (Leicester, UK). To achieve these aims, we sampled AM from Ethiopian mothers and children, and from UK adults and children using induced sputum (IS). AM were imaged under light microscopy, and the total two-dimensional surface area of carbon within each AM determined by image analysis. AM containing carbon were detected in all subjects. The total surface area of carbon per AM was higher in Ethiopian women (n=10) compared with UK adults (n=10, median 9.19 vs. 0.71 microm2/AM, p=0.0002). Similarly, the total surface area of carbon per AM was higher in Ethiopian children (n=10) compared with UK children (n=10, 3.32 vs. 0.44 microm2/AM, p=0.0002). However, loading in Ethiopian children was lower than paired maternal levels (3.32 vs. 9.19 microm2/AM, p=0.011). We conclude that analysis of AM obtained by induced sputum is a practical way of quantifying natural exposure of the lower airway to carbonaceous particles from the burning of biomass fuels.
NASA Astrophysics Data System (ADS)
Lee, H.; Park, J.; Cho, S.; Lee, S. J.; Kim, H. S.
2017-12-01
Forest determines the amount of water available to low land ecosystems, which use the rest of water after evapotranspiration by forests. Substantial increase of drought, especially for seasonal drought, has occurred in Korea due to climate change, recently. To cope with this increasing crisis, it is necessary to predict the water use of forest. In our study, forest water use in the Gyeonggi Province in Korea was estimated using high-resolution (spatial and temporal) meteorological forecast data and localized Joint UK Land Environment Simulator (JULES) which is one of the widely used land surface models. The modeled estimation was used for developing forest drought index. The localization of the model was conducted by 1) refining the existing two tree plant functional types (coniferous and deciduous trees) into five (Quercus spp., other deciduous tree spp., Pinus spp., Larix spp., and other coniferous spp.), 2) correcting moderate resolution imaging spectroradiometer (MODIS) leaf area index (LAI) through data assimilation with in situ measured LAI, and 3) optimizing the unmeasured plant physiological parameters (e.g. leaf nitrogen contents, nitrogen distribution within canopy, light use efficiency) based on sensitivity analysis of model output values. The high-resolution (hourly and 810 × 810 m) National Center for AgroMeteorology-Land-Atmosphere Modeling Package (NCAM-LAMP) data were employed as meteorological input data in JULES. The plant functional types and soil texture of each grid cell in the same resolution with that of NCAM-LAMP was also used. The performance of the localized model in estimating forest water use was verified by comparison with the multi-year sapflow measurements and Eddy covariance data of Taehwa Mountain site. Our result can be used as referential information to estimate the forest water use change by the climate change. Moreover, the drought index can be used to foresee the drought condition and prepare to it.
Impact of managed moorland burning on DOC concentrations in soil solutions and stream waters
NASA Astrophysics Data System (ADS)
Palmer, Sheila; Wearing, Catherine; Johnson, Kerrylyn; Holden, Joseph; Brown, Lee
2013-04-01
In the UK uplands, prescribed burning of moorland vegetation is a common practice to maintain suitable habitats for game birds. Many of these landscapes are in catchments covered by significant deposits of blanket peat (typically one metre or more in depth). There is growing interest in the effect of land management on the stability of these peatland carbon stores, and their contribution to dissolved and particulate organic carbon in surface waters (DOC and POC, respectively) and subsequent effects on stream biogeochemistry and ecology. Yet there are surprisingly few published catchment-scale studies on the effect of moorland burning on DOC and POC. As part of the EMBER project, stream chemistry data were collected approximately monthly in ten upland blanket peat catchments in the UK, five of which acted as controls and were not subject to burning. The other five catchments were subject to a history of prescribed burning, typically in small patches (300-900 m2) in rotations of 8-25 years. Soil solution DOC was also monitored at four depths at two intensively studied sites (one regularly burned and one control). At the two intensive sites, soil solution DOC was considerably higher at the burned site, particularly in surface solutions where concentrations in excess of 100 mg/L were recorded on several occasions (median 37 mg/L over 18 months). The high soil solution DOC concentrations at the burned site occurred in the most recently burned plots (less than 2 years prior to start of sampling) and the lowest DOC concentrations were observed in plots burned 15-25 years previously. On average, median stream DOC and POC concentrations were approximately 43% and 35% higher respectively in burned catchments relative to control catchments. All streams exhibited peak DOC in late summer/early autumn with higher peak DOC concentrations in burned catchments (20-66 mg/L) compared to control catchments (18-54 mg/L). During winter months, DOC concentrations were low in control catchments (typically less than 15 mg/L) but were highly variable in burned catchments (9-40 mg/L), implying some instability of peat carbon stores and/or fluctuation in source. The results offer strong evidence for an impact of burning on the delivery of DOC to streams, possibly through increased surface run-off from bare or partially vegetated patches.
Impact of river restoration on groundwater - surface water - interactions
NASA Astrophysics Data System (ADS)
Kurth, Anne-Marie; Schirmer, Mario
2014-05-01
Since the end of the 19th century, flood protection was increasingly based on the construction of impermeable dams and side walls (BWG, 2003). In spite of providing flood protection, these measures also limited the connectivity between the river and the land, restricted the area available for flooding, and hampered the natural flow dynamics of the river. Apart from the debilitating effect on riverine ecosystems due to loss of habitats, these measures also limited bank filtration, inhibited the infiltration of storm water, and affected groundwater-surface water-interactions. This in turn had a profound effect on ecosystem health, as a lack of groundwater-surface water interactions led to decreased cycling of pollutants and nutrients in the hyporheic zone and limited the moderation of the water temperature (EA, 2009). In recent decades, it has become apparent that further damages to riverine ecosystems must be prohibited, as the damages to ecology, economy and society surmount any benefits gained from exploiting them. Nowadays, the restoration of rivers is a globally accepted means to restore ecosystem functioning, protect water resources and amend flood protection (Andrea et al., 2012; Palmer et al., 2005; Wortley et al., 2013). In spite of huge efforts regarding the restoration of rivers over the last 30 years, the question of its effectiveness remains, as river restorations often reconstruct a naturally looking rather than a naturally functioning stream (EA, 2009). We therefore focussed our research on the effectiveness of river restorations, represented by the groundwater-surface water-interactions. Given a sufficiently high groundwater level, a lack of groundwater-surface water-interactions after restoration may indicate that the vertical connectivity in the stream was not fully restored. In order to investigate groundwater-surface water-interactions we determined the thermal signature on the stream bed and in +/- 40 cm depth by using Distributed Temperature Sensing (DTS), a fibre optical method for temperature determination over long distances (Selker et al., 2006). Thermal signatures were determined in a small urban stream before and after restoration and compared to streams in natural and near-natural settings. BWG BUNDESAMT FÜR WASSER UND GEOLOGIE, 2003. Die Geschichte des Hochwasserschutzes in der Schweiz. Bericht des BWG, Serie Wasser. Biel. 208 p. EA ENVIRONMENT AGENCY (UK), 2009. The Hyporheic Handbook: A handbook on the groundwater-surface water interface and hyporheic zone for environment managers. Bristol. 280 p. ANDREA, F., GSCHÖPF, C., BLASCHKE, A.P., WEIGELHOFER, G., AND RECKENDORFER, W., 2012. Ecological niche models for the evaluation of management options in urban floodplain - conservation vs. restoration purposes. Environ. Sci. Policy, http://dx.doi.org/10.1016/j.envsci.2012.08.011. PALMER, M.A., BERNHARDT, E.S., ALLAN, J.D., LAKE, P.S., ALEXANDER, G., BROOKS, S., CARR, J., CLAYTON, S., DAHM, C.N., FOLLSTAD SHAH, J., GALAT, D.L., LOSS, S.G., GOODWIN, P., HART, D.D., HASSETT, B., JENKINSON, R., KONDOLF, G.M., LAVE, R., MEYER, J.L., O`DONNELL, T.K., PAGANO, L. AND SUDDUTH, E., 2005. Standards for ecologically successful river restoration. Journal of Applied Ecology, 42, pp. 208 - 217. DOI 10.1111/j.1365-2664.2005.01004.x. WORTLEY, L., HERO, J-M., HOWES, M., 2013. Evaluating Ecological Restoration Success: A Review of the Literature. Restoration Ecology, 21 (5), pp. 537 - 543. DOI 10.1111/rec.12028. SELKER, J.S., THEVENAZ, L., HUWALD, H., MALLET, A., LUXEMBURG, W., VAN DE GIESEN, N., STEJSKAL, M., ZEMAN, J., WESTHOFF, M., AND PARLANGE, M.B., 2006. Distributed fibre-optic temperature sensing for hydrologic systems. Water Resources Research, 42(12), W12202.
NASA Astrophysics Data System (ADS)
Lansdown, Katrina; Heppell, Kate; Ullah, Sami; Heathwaite, A. Louise; Trimmer, Mark; Binley, Andrew; Heaton, Tim; Zhang, Hao
2010-05-01
The dynamics of groundwater and surface water mixing and associated nitrogen transformations in the hyporheic zone have been investigated within a gaining reach of a groundwater-fed river (River Leith, Cumbria, UK). The regional aquifer consists of Permo-Triassic sandstone, which is overlain by varying depths of glaciofluvial sediments (~15 to 50 cm) to form the river bed. The reach investigated (~250m long) consists of a series of riffle and pool sequences (Käser et al. 2009), with other geomorphic features such as vegetated islands and marginal bars also present. A network of 17 piezometers, each with six depth-distributed pore water samplers based on the design of Rivett et al. (2008), was installed in the river bed in June 2009. An additional 18 piezometers with a single pore water sampler were installed in the riparian zone along the study reach. Water samples were collected from the pore water samplers on three occasions during summer 2009, a period of low flow. The zone of groundwater-surface water mixing within the river bed sediments was inferred from depth profiles (0 to 100 cm) of conservative chemical species and isotopes of water with the collected samples. Sediment cores collected during piezometer installation also enabled characterisation of grain size within the hyporheic zone. A multi-component mixing model was developed to quantify the relative contributions of different water sources (surface water, groundwater and bank exfiltration) to the hyporheic zone. Depth profiles of ‘predicted' nitrate concentration were constructed using the relative contribution of each water source to the hyporheic and the nitrate concentration of the end members. This approach assumes that the mixing of different sources of water is the only factor controlling the nitrate concentration of pore water in the river bed sediments. Comparison of predicted nitrate concentrations (which assume only mixing of waters with different nitrate concentrations) with actual nitrate concentrations (measured from samples collected in the field) then allows patches of biogeochemical activity to be identified. The depth of the groundwater-surface water mixing zone was not uniform along the study reach or over the three sampling periods, varying from <10 to 50 cm in depth. The influence of factors such as the strength of groundwater upwelling, channel geomorphology, substrate composition (permeability) and river discharge on the extent of groundwater-surface mixing have been investigated. During the three field campaigns conducted, groundwater nitrate concentrations (100 cm) were higher than surface water nitrate concentrations (3.7 ± 0.4 mg N/L versus 2.0 ± 0.03 mg N/L; p < 0.001; n = 27), indicating that throughout the reach investigated groundwater will supply nitrate to the overlying water column unless nitrate attenuation occurs along the upwelling flow path. Actual (measured) pore water nitrate concentrations often differed from concentrations predicted using the mixing model, which suggests that biogeochemical transformations also affected nitrate concentrations in the hyporheic zone. The initial field data suggested that there were regions of both nitrate production and nitrate consumption in the subsurface sediments, and that these zones may extend beyond the depths commonly associated with the hyporheic zone. This research demonstrates that a multi-component mixing model can be used to identify possible hotspots of nitrate production or consumption in the bed of a groundwater-fed river. Käser, DH, Binley, A, Heathwaite, AL and Krause, S (2009) Spatio-temporal variations of hyporheic flow in a riffle-pool sequence. Hydrological Processes 23: 2138 - 2149. Rivett, MO, Ellis, PA, Greswell, RB, Ward, RS, Roche, RS, Cleverly, MG, Walker, C, Conran, D, Fitzgerald, PJ, Willcox, T and Dowle, J (2008) Cost-effective mini drive-point piezometers and multilevel samplers for monitoring the hyporheic zone. Quarterly Journal of Engineering Geology and Hydrogeology 41: 49 - 60.
Long Term Large Scale river nutrient changes across the UK
NASA Astrophysics Data System (ADS)
Bell, Victoria; Naden, Pam; Tipping, Ed; Davies, Helen; Davies, Jessica; Dragosits, Ulli; Muhammed, Shibu; Quinton, John; Stuart, Marianne; Whitmore, Andy; Wu, Lianhai
2017-04-01
During recent decades and centuries, pools and fluxes of Carbon, Nitrogen and Phosphorus (C, N and P) in UK rivers and ecosystems have been transformed by the spread and fertiliser-based intensification of agriculture (necessary to sustain human populations), by atmospheric pollution, by human waste (rising in line with population growth), and now by climate change. The principal objective of the UK's NERC-funded Macronutrients LTLS research project has been to account for observable terrestrial and aquatic pools, concentrations and fluxes of C, N and P on the basis of past inputs, biotic and abiotic interactions, and transport processes. More specifically, over the last 200 years, what have been the temporal responses of plant and soil nutrient pools in different UK catchments to nutrient enrichment, and what have been the consequent effects on nutrient transfers from land to the atmosphere, freshwaters and estuaries? The work described here addresses the second question by providing an integrated quantitative description of the interlinked land and water pools and annual fluxes of C, N and P for UK catchments over time. A national-scale modelling environment has been developed, combining simple physically-based gridded models that can be parameterised using recent observations before application to long timescales. The LTLS Integrated Model (LTLS-IM) uses readily-available driving data (climate, land-use, nutrient inputs, topography), and model estimates of both terrestrial and freshwater nutrient loads have been compared with measurements from sites across the UK. Here, the focus is on the freshwater nutrient component of the LTLS-IM, but the terrestrial nutrient inputs required for this are provided by models of nutrient processes in semi-natural and agricultural systems, and from simple models of nutrients arising from human waste. In the freshwater model, lateral routing of dissolved and particulate nutrients and within-river processing such as denitrification, decomposition and chlorophyll growth are undertaken, and the effects of groundwater storage and processes in lakes connected to the river network can be included. Following assessment against observations of terrestrial and nutrient fluxes in rivers across the UK, the LTLS-IM has been run nationally for 200 years (1800 to 2010), and the work presented here provides, for the first time, national, regional or catchment estimates of the origins and trends in riverine nutrients in the period following the industrial revolution. Ongoing work is now exploring the effects of future climate, waste water treatment and land-management scenarios on water quality, and the effects of nutrient enrichment on the development of eutrophication in rivers.
Preposition Entries in UK Monolingual Learners' Dictionaries: Problems and Possible Solutions.
ERIC Educational Resources Information Center
Lindstromberg, Seth
2001-01-01
Presents a selective examination of the entries of the preposition "on" in five advanced learners' dictionaries published in the United Kingdom. The principal concern is the preposition "on" as a signifier of contact with a surface--especially an upper surface. (Author/VWL)
Assessing climate change and socio-economic uncertainties in long term management of water resources
NASA Astrophysics Data System (ADS)
Jahanshahi, Golnaz; Dawson, Richard; Walsh, Claire; Birkinshaw, Stephen; Glenis, Vassilis
2015-04-01
Long term management of water resources is challenging for decision makers given the range of uncertainties that exist. Such uncertainties are a function of long term drivers of change, such as climate, environmental loadings, demography, land use and other socio economic drivers. Impacts of climate change on frequency of extreme events such as drought make it a serious threat to water resources and water security. The release of probabilistic climate information, such as the UKCP09 scenarios, provides improved understanding of some uncertainties in climate models. This has motivated a more rigorous approach to dealing with other uncertainties in order to understand the sensitivity of investment decisions to future uncertainty and identify adaptation options that are as far as possible robust. We have developed and coupled a system of models that includes a weather generator, simulations of catchment hydrology, demand for water and the water resource system. This integrated model has been applied in the Thames catchment which supplies the city of London, UK. This region is one of the driest in the UK and hence sensitive to water availability. In addition, it is one of the fastest growing parts of the UK and plays an important economic role. Key uncertainties in long term water resources in the Thames catchment, many of which result from earth system processes, are identified and quantified. The implications of these uncertainties are explored using a combination of uncertainty analysis and sensitivity testing. The analysis shows considerable uncertainty in future rainfall, river flow and consequently water resource. For example, results indicate that by the 2050s, low flow (Q95) in the Thames catchment will range from -44 to +9% compared with the control scenario (1970s). Consequently, by the 2050s the average number of drought days are expected to increase 4-6 times relative to the 1970s. Uncertainties associated with urban growth increase these risks further. Adaptation measures, such as new reservoirs can manage these risks to a certain extent, but our sensitivity testing demonstrates that they are less robust to future uncertainties than measures taken to reduce water demand. Keywords: Climate change, Uncertainty, Decision making, Drought, Risk, Water resources management.
Brooks, Emma; Freeman, Christopher; Gough, Rachel; Holliman, Peter J
2015-12-15
Rising dissolved organic carbon (DOC) concentrations in many upland UK catchments represents a challenge for drinking water companies, in particular due to the role of DOC as a precursor in the formation of trihalomethanes (THMs). Whereas traditionally, the response of drinking water companies has been focussed on treatment processes, increasingly, efforts have been made to better understanding the role of land use and catchment processes in affecting drinking water quality. In this study, water quality, including DOC and THM formation potential (THMFP) was assessed between the water source and finished drinking water at an upland and a lowland catchment. Surprisingly, the lowland catchment showed much higher reservoir DOC concentrations apparently due to the influence of a fen within the catchment from where a major reservoir inflow stream originated. Seasonal variations in water quality were observed, driving changes in THMFP. However, the reservoirs in both catchments appeared to dampen these temporal fluctuations. Treatment process applied in the 2 catchments were adapted to reservoir water quality with much higher DOC and THMFP removal rates observed at the lowland water treatment works where coagulation-flocculation was applied. However, selectivity during this DOC removal stage also appeared to increase the proportion of brominated THMs produced. Copyright © 2015. Published by Elsevier B.V.
Palmer, Antony L; Pearson, Michael; Whittard, Paul; McHugh, Katie E; Eaton, David J
2016-12-01
To assess the status and practice of kilovoltage (kV) radiotherapy in the UK. 96% of the radiotherapy centres in the UK responded to a comprehensive survey. An analysis of the installed equipment base, patient numbers, clinical treatment sites, quality control (QC) testing and radiation dosimetry processes were undertaken. 73% of UK centres have at least one kV treatment unit, with 58 units installed across the UK. Although 35% of units are over 10 years old, 39% units have been installed in the last 5 years. Approximately 6000 patients are treated with kV units in the UK each year, the most common site (44%) being basal cell carcinoma. A benchmark of QC practice in the UK is presented, against which individual centres can compare their procedures, frequency of testing and acceptable tolerance values. We propose the use of internal "notification" and "suspension" levels for analysis. All surveyed centres were using recommended Codes of Practice for kV dosimetry in the UK; approximately the same number using in-air and in-water methodologies for medium energy, with two-thirds of all centres citing "clinical relevance" as the reason for choice of code. 64% of centres had hosted an external dosimetry audit within the last 3 years, with only one centre never being independently audited. The majority of centres use locally measured applicator factors and published backscatter factors for treatments. Monitor unit calculations are performed using software in only 36% of centres. A comprehensive review of current kV practice in the UK is presented. Advances in knowledge: Data and discussion on contemporary kV radiotherapy in the UK, with a particular focus on physics aspects.
Pearson, Michael; Whittard, Paul; McHugh, Katie E; Eaton, David J
2016-01-01
Objective: To assess the status and practice of kilovoltage (kV) radiotherapy in the UK. Methods: 96% of the radiotherapy centres in the UK responded to a comprehensive survey. An analysis of the installed equipment base, patient numbers, clinical treatment sites, quality control (QC) testing and radiation dosimetry processes were undertaken. Results: 73% of UK centres have at least one kV treatment unit, with 58 units installed across the UK. Although 35% of units are over 10 years old, 39% units have been installed in the last 5 years. Approximately 6000 patients are treated with kV units in the UK each year, the most common site (44%) being basal cell carcinoma. A benchmark of QC practice in the UK is presented, against which individual centres can compare their procedures, frequency of testing and acceptable tolerance values. We propose the use of internal “notification” and “suspension” levels for analysis. All surveyed centres were using recommended Codes of Practice for kV dosimetry in the UK; approximately the same number using in-air and in-water methodologies for medium energy, with two-thirds of all centres citing “clinical relevance” as the reason for choice of code. 64% of centres had hosted an external dosimetry audit within the last 3 years, with only one centre never being independently audited. The majority of centres use locally measured applicator factors and published backscatter factors for treatments. Monitor unit calculations are performed using software in only 36% of centres. Conclusion: A comprehensive review of current kV practice in the UK is presented. Advances in knowledge: Data and discussion on contemporary kV radiotherapy in the UK, with a particular focus on physics aspects. PMID:27730839
NASA Astrophysics Data System (ADS)
Konadu, D. D.; Sobral Mourao, Z.
2016-12-01
Transitioning to a low-carbon power system has been identified as one of the main strategies for achieving GHG emissions reduction targets stipulated in the UK Climate Change Act (2008). However, projected mix of technologies aimed at achieving the targeted level of decarbonisation have implications for sustainable level natural resource exploitation at different spatial and temporal scales. Critical among these are the impact on land use (food production) and water resources, which are usually not adequately analysed and accounted for in developing these long-term energy system transition strategies and scenarios. Given the importance of the UK power sector to meeting economy-wide emissions targets, the overall environmental consequence of the prescribed scenarios could significantly affect meeting long-term legislated GHG emission reduction targets. It is therefore imperative that synergies and trade-offs between the power systems and these resources are comprehensively analysed. The current study employs an integrated energy and resource use accounting methodology, called ForeseerTM, to assess the land and water requirement for the deployment of the power sector technologies of the UK Committee on Climate Change (CCC) Carbon Budget scenarios. This is analysed under different scenarios of energy crop yield and electricity infrastructure location. The outputs are then compared with sustainable limits of resource exploitation to establish the environmental tractability of the scenarios. The results show that even if stringent environmental and land use restrictions are applied, all the projected bioenergy and ground-mounted solar PV can be deployed within the UK with no significant impacts on land use and food production. However, inland water resources would be significantly affected if high Carbon Capture and Storage deployment, and without new nuclear capacity. Overall, the output highlights that contrary to the notion of the inevitability of CCS deployment in delivering emissions reduction targets, a future without CCS poses the least overall environmental impacts.
Geoethical Approach to Antarctic Subglacial Lakes Exploration
NASA Astrophysics Data System (ADS)
Talalay, Pavel; Markov, Alexey; Sysoev, Mikhail
2014-05-01
Antarctic subglacial aquatic environment have become of great interest to the science community because they may provide unique information about microbial evolution, the past climate of the Earth, and the formation of the Antarctic ice sheet. Nowadays it is generally recognized that a vast network of lakes, rivers, and streams exists thousands of meters beneath Antarctic Ice Sheets. Up to date only four boreholes accessed subglacial aquatic system but three of them were filled with high-toxic drilling fluid, and the subglacial water was contaminated. Two recent exploration programs proposed by UK and USA science communities anticipated direct access down to the lakes Ellsworth and Whillans, respectively, in the 2012/2013 Antarctic season. A team of British scientists and engineers engaged in the first attempt to drill into Lake Ellsworth but failed. US research team has successfully drilled through 800 m of Antarctic ice to reach a subglacial lake Whillans and retrieve water and sediment samples. Both activities used hot-water drilling technology to access lakes. Hot water is considered by the world science community as the most clean drilling fluid medium from the present point of view but it cannot solve environmental problems in total because hot-water even when heated to 90 °C, filtered to 0.2 μm, and UV treated at the surface could pick up microorganisms from near-surface snow and circulate them in great volume through the borehole. Another negative impact of hot-water circulation medium is thermal pollution of subglacial water. The new approach to Antarctic subglacial lakes exploration is presented by sampling technology with recoverable autonomous sonde which is equipped by two hot-points with heating elements located on the bottom and top sides of the sonde. All down-hole sonde components will be sterilized by combination of chemical wash, HPV and UV sterilization prior using. At the beginning of the summer season sonde is installed on the surface of the Antarctic ice sheet above subglacial lake. All equipment is got into working trim, the bottom hot-point is powered, and the sonde starts to melt down to the ice sheet bed. The personnel leave the site, and all further operations are going on in semi-automatic mode. The melted water does not recover from the hole and refreezes behind the sonde. Electric line for power supply and communication with down-hole sensors is released from the coil installed inside the sonde. Since the sonde enters into the subglacial lake, it samples the water and examines subglacial conditions. After sampling, the motor connected with coil is switched on, and the top hot-point is put into action. The sonde begins to recover itself to the surface by spooling the cable and melting overlying ice with the help of the upper hot-point. Since 8-9 months from starting, the sonde reaches the surface and waits the personnel for servicing and moving to the next site. The big advantage of the proposed technology is that subglacial lake would be measured and sampled while subglacial water is reliably isolated from surface environment.
Bio-Optical and Geochemical Properties of the South Atlantic Subtropical Gyre
NASA Technical Reports Server (NTRS)
Signorini, S. R.; Hooker, Stanford B.; McClain, Charles R.
2003-01-01
An investigation of the bio-optical properties of the South Atlantic subtropical gyre (SASG) was conducted using data primarily from the UK Atlantic Meridional Transect (AMT) program and SeaWiFS. The AMT cruises extend from the UK to the Falklands Islands (sailing on the RRS James Clark Ross) with the purpose of improving our knowledge of surface layer hydrography, biogeochemical processes, ecosystem dynamics and food webs across basin scales in the Atlantic Ocean. Two objectives of the AMT program relevant to this study are the characterization of biogeochemical provinces and the analysis of optical and pigment parameters in connection with remote sensing ocean color data. The primary focus of this NASA Technical Memorandum is on the variability of the vertical distribution of phytoplankton pigments and associated absorption properties across the SASG, and their relevance to remote sensing algorithms. Therefore, a subset of the AMT data within the SASG from all available cruises was used in the analyses. One of the challenges addressed here is the determination of the SASG geographic boundaries. One of the major problems is to reconcile the properties of biogeochemical provinces. We use water mass analysis, dynamics of ocean currents, and meridional gradients of bio-optical properties, to identify the SASG boundaries.
De Vooght-Johnson, Ryan
2011-03-01
An evening symposium was held at the Museu de Historia de Catalunya (Barcelona, Spain) as a precursor to the European Bioanalysis Forum meeting, as part of the Waters Corporation Bioanalysis World Tour. The symposium was chaired by Robert Plumb and Jing Lin (Waters Corporation, MA, USA) with a focus on the future of the DMPK laboratory and its role in addressing large-molecule therapeutics and biomarkers. Lieve Dillen (Johnson and Johnson, Belgium) spoke on ultra-sensitive peptide quantification, Richard Kay (Quotient Bioresearch, UK) discussed quantifying proteins and peptides in plasma, Ian Wilson (AstraZeneca, UK) covered metabolic biomarkers and Robert Plumb concluded the evening with a presentation on the future of MS in DMPK studies. Following the presentations, all the speakers took questions from the audience and continued lively discussion over a cocktails and canapés reception.
U. K. to resume natural gas imports
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1992-02-17
This paper reports that the U.K. government has opened the way for resuming gas imports into Britain by approving a contract signed by U.K. electric power utility National Power to buy gas from Norway. A new joint marketing venture of BP Exploration, Den norske stats oljeselskap AS (Statoil), and Norsk Hydro AS also will be allowed to import gas for electric power plant fuel once it has a contract. National Power and the BP/Statoil/Norsk Hydro group will use the Frigg pipeline from Norwegian waters into St. Fergus, north of Aberdeen, the only existing link between the British transmission system andmore » foreign supplies of gas. Meantime, progress is under way toward a second pipeline to link the U.K. with foreign natural gas supplies, calling for a pipeline across the English Channel joining the continental European pipeline system to the U.K. network.« less
NASA Astrophysics Data System (ADS)
Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Newell, Andrew J.
2015-04-01
The first UK city-wide heat map is described based on measurements of groundwater from a shallow superficial aquifer in the coastal city of Cardiff, Wales, UK. The UK Government has a target of reducing greenhouse gas emissions by 80% by 2050 (Climate Change Act 2008) and low carbon technologies are key to achieving this. To support the use of ground source heating we characterised the shallow heat potential of an urban aquifer to produce a baseline dataset which is intended to be used as a tool to inform developers and to underpin planning and regulation. We exploited an existing network of 168 groundwater monitoring boreholes across the city, recording the water temperature in each borehole at 1m depth intervals up to a depth of 20m. We recorded groundwater temperatures during the coldest part of 2014, and repeat profiling of the boreholes in different seasons has added a fourth dimension to our results and allowed us to characterise the maximum depth of seasonal temperature fluctuation. The temperature profiles were used to create a 3D model of heat potential within the aquifer using GOCAD® and the average borehole temperatures were contoured using Surfer® 10 to generate a 2D thermal resource map to support future assessment of urban Ground Source Heat Pumps prospectively. The average groundwater temperature in Cardiff was found to be above the average for England and Wales (11.3°C) with 90% of boreholes in excess of this figure by up to 4°C. The subsurface temperature profiles were also found to be higher than forecast by the predicted geothermal gradient for the area. Potential sources for heat include: conduction from buildings, basements and sub-surface infrastructure; insulation effects of the urban area and of the geology, and convection from leaking sewers. Other factors include recharge inhibition by drains, localised confinement and rock-water interaction in specific geology. It is likely to be a combination of multiple factors which we are hoping to make the focus of future study. The next stage of this work will be to develop conceptual models of the thermal groundwater regime, and monitoring under abstraction conditions to confirm the sustainability of groundwater temperatures as a long-term thermal resource. We have also instrumented a non-infiltration Sustainable Urban Drainage System (SuDS) scheme, where we will characterise the effect upon the thermal groundwater resource as localised infiltration is reduced.
Understanding the structure of Exmoor's peatland ecosystems using laser-scanning technologies
NASA Astrophysics Data System (ADS)
Luscombe, D. J.; Anderson, K.; Wetherelt, A.; Grand-Clement, E.; Le-Feuvre, N.; Smith, D.; Brazier, R. E.
2012-04-01
Upland blanket peatlands in the UK are of high conservation value and in an intact state, provide important landscape services, such as carbon sequestration and flood attenuation. The drainage of many such wetlands for agricultural reclamation has resulted in changes to upland blanket mire topography, ecology, hydrological processes and carbon fluxes. There is a need for spatially explicit monitoring approaches at peatland sites in the UK as although there has been a national effort to restore drained peat uplands, baseline and post restoration monitoring of changes to ecosystem structure and function is largely absent. Climate change policy and the emerging carbon markets also necessitate the need for enhanced system understanding to inform carbon targets and understand the impacts of restoration. Exmoor is the focus of this research because many areas of upland peat have, in the past, been extensively drained through government "moorland reclamation" programs. A large restoration project funded by South West Water is currently underway in association with Exmoor National Park, The Environment Agency and Natural England. Exmoor also provides an analogue for other westerly peatlands in the British Isles in terms of its climate, ecology and drainage characteristics. Our approach employed airborne LiDAR data gathered by the Environment Agency Geomatics Group coupled with Terrestrial Laser Scanning (TLS) surveys. LiDAR data were processed to produce digital surface models (DSM) of the peatland surface at a 0.5m resolution. These data were further interrogated to separate vegetation structures and geomorphic features such as man-made drainage channels which have damaged the peatland. Over small extents the LiDAR derived DSM surface was then compared to a TLS derived DSM to examine the ability of these models to describe fine scale vegetation and geomorphic structure, which could then be extrapolated to larger spatial extents. Exploration of the data has shown that ecosystem structure can be described at a fine resolution (>10 million measurements, resolution
Modelling potential production of macroalgae farms in UK and Dutch coastal waters
NASA Astrophysics Data System (ADS)
van der Molen, Johan; Ruardij, Piet; Mooney, Karen; Kerrison, Philip; O'Connor, Nessa E.; Gorman, Emma; Timmermans, Klaas; Wright, Serena; Kelly, Maeve; Hughes, Adam D.; Capuzzo, Elisa
2018-02-01
There is increasing interest in macroalgae farming in European waters for a range of applications, including food, chemical extraction for biofuel production. This study uses a 3-D numerical model of hydrodynamics and biogeochemistry to investigate potential production and environmental effects of macroalgae farming in UK and Dutch coastal waters. The model included four experimental farms in different coastal settings in Strangford Lough (Northern Ireland), in Sound of Kerrera and Lynn of Lorne (north-west Scotland) and in the Rhine plume (the Netherlands), as well as a hypothetical large-scale farm off the UK north Norfolk coast. The model could not detect significant changes in biogeochemistry and plankton dynamics at any of the farm sites averaged over the farming season. The results showed a range of macroalgae growth behaviours in response to simulated environmental conditions. These were then compared with in situ observations where available, showing good correspondence for some farms and less good correspondence for others. At the most basic level, macroalgae production depended on prevailing nutrient concentrations and light conditions, with higher levels of both resulting in higher macroalgae production. It is shown that under non-elevated and interannually varying winter nutrient conditions, farming success was modulated by the timings of the onset of increasing nutrient concentrations in autumn and nutrient drawdown in spring. Macroalgae carbohydrate content also depended on nutrient concentrations, with higher nutrient concentrations leading to lower carbohydrate content at harvest. This will reduce the energy density of the crop and thus affect its suitability for conversion into biofuel. For the hypothetical large-scale macroalgae farm off the UK north Norfolk coast, the model suggested high, stable farm yields of macroalgae from year to year with substantial carbohydrate content and limited environmental effects.
Carbonate chemistry of surface waters in a temperate karst region: the southern Yorkshire Dales, UK
NASA Astrophysics Data System (ADS)
Pentecost, Allan
1992-11-01
A detailed study of surface water chemistry is described from an important limestone region in northern England. Major ions and pH were determined for 485 sites (springs, seeps, streams, rivers and lakes) during summertime. The saturation state of the waters with respect to calcite was determined as the calcite saturation ratio (Ω). An unexpectedly large number of samples were found to be supersaturated (65.5% of the 268 km of watercourses surveyed). As a consequence, several streams entering major cave systems were incapable of further limestone solution, at least during periods of low flow. Many waters were supersaturated from their source and some deposited travertine. A significant negative correlation was found between spring discharge and both (Ω) and pH. Supersaturation was caused primarily by atmospheric degassing, with some contribution from aquatic plant photosynthesis. The median total dissolved inorganic carbon and Ca concentrations were 2.49 and 1.35 millimoles 1 -1 respectively. Calcium originated exclusively from limestone, and carbon dioxide mainly from the soil and dissolved limestone. South facing catchments provided springwaters with significantly higher levels of TDIC and Ca when compared with north facing catchments. The study suggests that acid rain made a measurable contribution to limestone dissolution. Carboniferous limestone denudation rates were estimated as 54 to 63 m 3 km -2 a -1 (54 to 63 mm 1000 years -1). About 50% of the Mg came from limestone and the remainder, together with most K, Na, SO 4 and Cl from precipitation. Concentrations of dissolved nutrients were low, medians for NO 3, NH 4, total PO 4 and SiO 3 were 24 μmol, 1.4 μmol, 0.64 μmol and 15.5 μmol 1 -1 respectively. The concentration of a further 23 trace elements was determined.
Ockenden, Mary C; Deasy, Clare; Quinton, John N; Surridge, Ben; Stoate, Chris
2014-03-15
Intensification of agriculture has resulted in increased soil degradation and erosion, with associated pollution of surface waters. Small field wetlands, constructed along runoff pathways, offer one option for slowing down and storing runoff in order to allow more time for sedimentation and for nutrients to be taken up by plants or micro-organisms. This paper describes research to provide quantitative evidence for the effectiveness of small field wetlands in the UK landscape. Ten wetlands were built on four farms in Cumbria and Leicestershire, UK. Annual surveys of sediment and nutrient accumulation in 2010, 2011 and 2012 indicated that most sediment was trapped at a sandy site (70 tonnes over 3 years), compared to a silty site (40 tonnes over 3 years) and a clay site (2 tonnes over 3 years). The timing of rainfall was more important than total annual rainfall for sediment accumulation, with most sediment transported in a few intense rainfall events, especially when these coincided with bare soil or poor crop cover. Nutrient concentration within sediments was inversely related to median particle size, but the total mass of nutrients trapped was dependent on the total mass of sediment trapped. Ratios of nutrient elements in the wetland sediments were consistent between sites, despite different catchment characteristics across the individual wetlands. The nutrient value of sediment collected from the wetlands was similar to that of soil in the surrounding fields; dredged sediment was considered to have value as soil replacement but not as fertiliser. Overall, small field wetlands can make a valuable contribution to keeping soil out of rivers. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
Passive sampling: A cost-effective method for understanding antibiotic fate, behaviour and impact.
Chen, Chang-Er; Zhang, Hao; Ying, Guang-Guo; Zhou, Li-Jun; Jones, Kevin C
2015-12-01
The occurrence of antibiotics in the environment has raised much concern in recent years. Understanding their release, fate and behaviour in the environment is vital to assess potential risks. In this study, a novel passive water sampler - diffusion gradients in thin-films for organics (o-DGT) - was employed to assess the occurrence and removal of antibiotics in two waste water treatment plants (WWTPs) - one in China and the other in the United Kingdom (UK). Of the targeted compounds, 11 of 19 were detected in the Chinese WWTP (ND-200ng/L) and 10 of 40 were found in the UK plant (ND-1380ng/L). Florfenicol, lincomycin, ofloxacin and roxithromycin were most abundant in the Chinese WWTP (influent), while anhydrous erythromycin, ciprofloxacin, trimethoprim, ofloxacin and sulfapyridine were the most abundant in the UK influent samples. Estimated Chinese and UK consumption data are used to interpret the results. Neither of the WWTPs was very effective at removing antibiotics: ~40-50% (overall) was removed by the two plants, with the rest being discharged into the receiving rivers. This is the first study using o-DGT to assess the occurrence and removal of antibiotics in WWTPs. o-DGT is a useful, cost-effective tool to assess WWTP performance and can highlight the effectiveness of treatment steps, which can be applied to wastewater based epidemiology studies. Copyright © 2015 Elsevier Ltd. All rights reserved.
Aetiology of injuries and the need for protective equipment for surfers in the UK.
Woodacre, Timothy; Waydia, Shree Eesh; Wienand-Barnett, Sophie
2015-01-01
Surfing is a popular UK water-sport. Previous studies investigating surfing injuries have been principally based on trauma from large waves and reef breaks in the US and Australia. Subsequent conclusions and recommendations for the use of protective equipment in surfing may therefore not be relevant in the UK. This study examines the aetiology of surfing injuries in the UK. Data was collected in 2012 using a web-based survey distributed to UK surfing clubs. Surfers recorded time/experience as a surfer, number of episodes spent surfing per month, different breaks surfed and type, frequency and method of any injuries sustained whilst surfing in the UK, including treatment received. Completed surveys were obtained from 130 individuals, M:F division 85:45, median age 28 (range 17-65). 122 surfers reported a total of 335 injuries. Head injuries were the most common (24%) followed by ankle (19%), knee (13%), back (10%), hand/wrist (9%), elbow/shoulder (7%), trunk (7%), neck (4%), hip (4%) and genitalia (3%) injuries. Surfers collided most often with their own boards (31%). The other collisions were with rocks/coral (15%), the sea (11%), other surf boards (10%) the sea bed (7%), other water vessels (2%) and by paddle-boards (1%). Of 327 injuries, cuts/lacerations (31%) were the commonest type of injury, followed by bruises/peri-orbital ecchymoses (24%), joint/ligament sprains (15%), muscle or tendon tears/ruptures (9%), concussion (5%), fractures (3%) and teeth injuries (1%). The remaining 8 injuries were not categorized. 65% of the surfers never required professional medical treatment for their differing injuries. There were no skull fractures and no head injuries required neurosurgical intervention. Surfing injuries in the UK are common. They appear of a similar aetiology to those reported in the literature in countries with a high surfing population, but generally of a lower severity, with few requiring professional treatment, hospital admission or operative intervention. Concussion appears rare and in this study there were no head injuries that required neurosurgical intervention. Surfing helmets aim to prevent such serious head injuries; whilst they should be considered for injury prevention their routine use is unlikely to be warranted whilst surfing in the UK. Copyright © 2014 Elsevier Ltd. All rights reserved.
A Global Observatory of Lake Water Quality
NASA Astrophysics Data System (ADS)
Tyler, Andrew N.; Hunter, Peter D.; Spyrakos, Evangelos; Neil, Claire; Simis, Stephen; Groom, Steve; Merchant, Chris J.; Miller, Claire A.; O'Donnell, Ruth; Scott, E. Marian
2017-04-01
Our planet's surface waters are a fundamental resource encompassing a broad range of ecosystems that are core to global biogeochemical cycling, biodiversity and food and energy security. Despite this, these same waters are impacted by multiple natural and anthropogenic pressures and drivers of environmental change. The complex interaction between physical, chemical and biological processes in surface waters poses significant challenges for in situ monitoring and assessment and this often limits our ability to adequately capture the dynamics of aquatic systems and our understanding of their status, functioning and response to pressures. Recent developments in the availability of satellite platforms for Earth observation (including ESA's Copernicus Programme) offers an unprecedented opportunity to deliver measures of water quality at a global scale. The UK NERC-funded GloboLakes project is a five-year research programme investigating the state of lakes and their response to climatic and other environmental drivers of change through the realization of a near-real time satellite based observatory (Sentinel-3) and archive data processing (MERIS, SeaWiFS) to produce a 20-year time-series of observed ecological parameters and lake temperature for more than 1000 lakes globally. However, the diverse and complex optical properties of lakes mean that algorithm performance often varies markedly between different water types. The GloboLakes project is overcoming this challenge by developing a processing chain whereby algorithms are dynamically selected according to the optical properties of the lake under observation. The development and validation of the GloboLakes processing chain has been supported by access to extensive in situ data from more than thirty partners around the world that are now held in the LIMNADES community-owned data repository developed under the auspices of GloboLakes. This approach has resulted in a step-change in our ability to produce regional and global water quality products for optically-complex waters complete with greatly improved uncertainty estimates. The value of these data and the future scientific opportunities they provide will be illustrated with examples of how it can be used to improve our understanding of the impact of global environmental change on inland, transitional and near-shore coastal waters.
Spatial variability of metals in the inter-tidal sediments of the Medway Estuary, Kent, UK.
Spencer, Kate L
2002-09-01
Concentrations of major and trace metals were determined in eight sediment cores collected from the inter-tidal zone of the Medway Estuary, Kent, UK. Metal associations and potential sources have been investigated using principal component analysis. These data provide the first detailed geochemical survey of recent sediments in the Medway Estuary. Metal concentrations in surface sediments lie in the mid to lower range for UK estuarine sediments indicating that the Medway receives low but appreciable contaminant inputs. Vertical metal distributions reveal variable redox zonation across the estuary and historically elevated anthropogenic inputs. Peak concentrations of Cu, Pb and Zn can be traced laterally across the estuary and their positions indicate periods of past erosion and/or non-deposition. However, low rates of sediment accumulation do not allow these sub surface maxima to be used as accurate geochemical marker horizons. The salt marshes and inter-tidal mud flats in the Medway Estuary are experiencing erosion, however the erosion of historically contaminated sediments is unlikely to re-release significant amounts of heavy metals to the estuarine system.
Improving UK Air Quality Modelling Through Exploitation of Satellite Observations
NASA Astrophysics Data System (ADS)
Pope, Richard; Chipperfield, Martyn; Savage, Nick
2014-05-01
In this work the applicability of satellite observations to evaluate the operational UK Met Office Air Quality in the Unified Model (AQUM) have been investigated. The main focus involved the AQUM validation against satellite observations, investigation of satellite retrieval error types and of synoptic meteorological-atmospheric chemistry relationships simulated/seen by the AQUM/satellite. The AQUM is a short range forecast model of atmospheric chemistry and aerosols up to 5 days. It has been designed to predict potentially hazardous air pollution events, e.g. high concentrations of surface ozone. The AQUM has only been validated against UK atmospheric chemistry recording surface stations. Therefore, satellite observations of atmospheric chemistry have been used to further validate the model, taking advantage of better satellite spatial coverage. Observations of summer and winter 2006 tropospheric column NO2 from both OMI and SCIAMACHY show that the AQUM generally compares well with the observations. However, in northern England positive biases (AQUM - satellite) suggest that the AQUM overestimates column NO2; we present results of sensitivity experiments on UK emissions datasets suspected to be the cause. In winter, the AQUM over predicts background column NO2 when compared to both satellite instruments. We hypothesise that the cause is the AQUM winter night-time chemistry, where the NO2 sinks are not substantially defined. Satellite data are prone to errors/uncertainty such as random, systematic and smoothing errors. We have investigated these error types and developed an algorithm to calculate and reduce the random error component of DOAS NO2 retrievals, giving more robust seasonal satellite composites. The Lamb Weather Types (LWT), an objective method of classifying the daily synoptic weather over the UK, were used to create composite satellite maps of column NO2 under different synoptic conditions. Under cyclonic conditions, satellite observed UK column NO2 is reduced as the indicative south-westerly flow transports it away from the UK over the North Sea. However, under anticyclonic conditions, the satellite shows that the stable conditions enhance the build-up of column NO2 over source regions. The influence of wind direction on column NO2 can also be seen from space with transport leeward of the source regions.
Starting a European Space Agency Sample Analogue Collection for Robotic Exploration Missions
NASA Astrophysics Data System (ADS)
Smith, C. L.; Mavris, C.; Michalski, J. R.; Rumsey, M. S.; Russell, S. S.; Jones, C.; Schroeven-Deceuninck, H.
2015-12-01
The Natural History Museum is working closely with the European Space Agency (ESA) and the UK Space Agency to develop a European collection of analogue materials with appropriate physical/mechanical and chemical (mineralogical) properties which can support the development and verification of both spacecraft and scientific systems for potential science and exploration missions to Phobos/Deimos, Mars, C-type asteroids and the Moon. As an ESA Collection it will be housed at the ESA Centre based at Harwell, UK. The "ESA Sample Analogues Collection" will be composed of both natural and artificial materials chosen to (as closely as possible) replicate the surfaces and near-surfaces of different Solar System target bodies of exploration interest. The analogue samples will be fully characterised in terms of both their physical/mechanical properties (compressive strength, bulk density, grain shape, grain size, cohesion and angle of internal friction) and their chemical/mineralogical properties (texture, modal mineralogy, bulk chemical composition - major, minor and trace elements and individual mineralogical compositions). The Collection will be fully curated to international standards including implementation of a user-friendly database and will be available for use by engineers and scientists across the UK and Europe. Enhancement of the initial Collection will be possible through collaborations with other ESA and UK Space Agency supported activities, such as the acquisition of new samples during field trials.
Scratching beneath the Surface of Communities of (Mal)practice
ERIC Educational Resources Information Center
Pemberton, Jon; Mavin, Sharon; Stalker, Brenda
2007-01-01
Purpose: This paper seeks to surface less positive aspects of communities of practice (CoPs), regardless of emergent or organisationally managed, grounded in political-power interactions. Examples are provided from the authors' experiences of a research-based CoP within UK higher education. Design/methodology/approach: The paper is primarily…
Panel Analyzes Pakistan's Internal Water Concerns
NASA Astrophysics Data System (ADS)
Showstack, Randy
2013-06-01
Although transboundary water issues between Pakistan and neighboring countries may be exciting and interesting, Pakistan's real water and security nexus is at the local level, according to Daanish Mustafa, coauthor of a new report, "Understanding Pakistan's Water-Security Nexus." Mustafa, a reader in politics and environment at King's College, London, U.K., was a panelist at a 30 May forum in Washington, D. C., sponsored by the United States Institute of Peace, which published the report.
Conflict for Resources: Water in the Lake Chad Basin
2009-01-01
Security 19 (1994), http://www.library.utoronto.ca/pcs/evidence (accessed 10 February 2009). 11 Miriam Lowi, Water and Power (Cambridge, UK : Cambridge...states wage wars and how scarce natural resources influence the states. Carl von Clausewitz’s treatise, On War serves as a starting point for any...has lots of water, very little of it is freshwater. Miriam Lowi, author of Water and Power describes political dynamics of high and low politics. High
NASA Astrophysics Data System (ADS)
Heppell, Catherine M.; Binley, Andrew; Trimmer, Mark; Darch, Tegan; Jones, Ashley; Malone, Ed; Collins, Adrian L.; Johnes, Penny J.; Freer, Jim E.; Lloyd, Charlotte E. M.
2017-09-01
The role that hydrology plays in governing the interactions between dissolved organic carbon (DOC) and nitrogen in rivers draining lowland, agricultural landscapes is currently poorly understood. In light of the potential changes to the production and delivery of DOC and nitrate to rivers arising from climate change and land use management, there is a pressing need to improve our understanding of hydrological controls on DOC and nitrate dynamics in such catchments. We measured DOC and nitrate concentrations in river water of six reaches of the lowland river Hampshire Avon (Wiltshire, southern UK) in order to quantify the relationship between BFI (BFI) and DOC : nitrate molar ratios across contrasting geologies (Chalk, Greensand, and clay). We found a significant positive relationship between nitrate and BFI (p < 0. 0001), and a significant negative relationship between DOC and BFI (p < 0. 0001), resulting in a non-linear negative correlation between DOC : nitrate molar ratio and BFI. In the Hampshire Avon, headwater reaches which are underlain by clay and characterized by a more flashy hydrological regime are associated with DOC : nitrate ratios > 5 throughout the year, whilst groundwater-dominated reaches underlain by Chalk, with a high BFI have DOC : nitrate ratios in surface waters that are an order of magnitude lower (< 0.5). Our analysis also reveals significant seasonal variations in DOC : nitrate transport and highlights critical periods of nitrate export (e.g. winter in sub-catchments underlain by Chalk and Greensand, and autumn in drained, clay sub-catchments) when DOC : nitrate molar ratios are low, suggesting low potential for in-stream uptake of inorganic forms of nitrogen. Consequently, our study emphasizes the tight relationship between DOC and nitrate availability in agricultural catchments, and further reveals that this relationship is controlled to a great extent by the hydrological setting.
Saharan dust plume charging observed over the UK
NASA Astrophysics Data System (ADS)
Harrison, R. Giles; Nicoll, Keri A.; Marlton, Graeme J.; Ryder, Claire L.; Bennett, Alec J.
2018-05-01
A plume of Saharan dust and Iberian smoke was carried across the southern UK on 16th October 2017, entrained into an Atlantic cyclone which had originated as Hurricane Ophelia. The dust plume aloft was widely noticed as it was sufficiently dense to redden the visual appearance of the sun. Time series of backscatter from ceilometers at Reading and Chilbolton show two plumes: one carried upwards to 2.5 km, and another below 800 m into the boundary layer, with a clear slot between. Steady descent of particles at about 50 cm s‑1 continued throughout the morning, and coarse mode particles reached the surface. Plumes containing dust are frequently observed to be strongly charged, often through frictional effects. This plume passed over atmospheric electric field sensors at Bristol, Chilbolton and Reading. Consistent measurements at these three sites indicated negative plume charge. The lower edge plume charge density was (‑8.0 ± 3.3) nC m‑2, which is several times greater than that typical for stratiform water clouds, implying an active in situ charge generation mechanism such as turbulent triboelectrification. A meteorological radiosonde measuring temperature and humidity was launched into the plume at 1412 UTC, specially instrumented with charge and turbulence sensors. This detected charge in the boundary layer and in the upper plume region, and strong turbulent mixing was observed throughout the atmosphere’s lowest 4 km. The clear slot region, through which particles sedimented, was anomalously dry compared with modelled values, with water clouds forming intermittently in the air beneath. Electrical aspects of dust should be included in numerical models, particularly the charge-related effects on cloud microphysical properties, to accurately represent particle behaviour and transport.
NASA Astrophysics Data System (ADS)
Venier, C.; Figueiredo da Silva, J.; McLelland, S. J.; Duck, R. W.; Lanzoni, S.
2012-10-01
This study aims to quantify the impact of macroalgal mats of Ulva intestinalis on flow dynamics and sediment stability. Such mats are becoming increasingly common in many coastal and estuarine intertidal habitats, thus it is important to determine whether they increase flow resistance, promote bed stability and therefore reduce the risk of erosion leading to tidal flooding or to degradation of coastal lagoons. The study has been carried out through a systematic series of experiments conducted in the large open-channel flume of the Total Environment Simulator (TES) facility, University of Hull, UK. The experimental facility was set up with a bed of fine sand, partially covered by strands of U. intestinalis; living individuals attached to large clasts were collected from Budle Bay, in the Lindisfarne National Nature Reserve, UK, and transplanted to the flume. The TES was equipped with acoustic doppler velocimetry (ADV) and acoustic backscatter (ABS) sensors, which measured current velocity, water level, bed level, and suspended sediment concentration. The experiments consisted of several unidirectional flow runs, firstly with a mobile sediment bed covered with U. intestinalis, then with a bare sediment surface, conducted at three different water depths. Under the investigated experimental range of velocities, typical of tidal environments, the macroalgal filaments were bent parallel to the sediment bed. The resulting velocity profile departed from the classical logarithmic trend, implying an increase of the overall roughness. This result reflects the different vertical Reynolds shear stress profiles and energy spectra features of the turbulent flow with respect to a bare sandy bed configuration. Macroalgae are also found to affect the morphological configuration of bedforms. The overall result is significant bio-stabilization, with increased flow resistance and reduced sediment transport.
JULES-crop: a parametrisation of crops in the Joint UK Land Environment Simulator
NASA Astrophysics Data System (ADS)
Osborne, T.; Gornall, J.; Hooker, J.; Williams, K.; Wiltshire, A.; Betts, R.; Wheeler, T.
2014-10-01
Studies of climate change impacts on the terrestrial biosphere have been completed without recognition of the integrated nature of the biosphere. Improved assessment of the impacts of climate change on food and water security requires the development and use of models not only representing each component but also their interactions. To meet this requirement the Joint UK Land Environment Simulator (JULES) land surface model has been modified to include a generic parametrisation of annual crops. The new model, JULES-crop, is described and evaluation at global and site levels for the four globally important crops; wheat, soy bean, maize and rice is presented. JULES-crop demonstrates skill in simulating the inter-annual variations of yield for maize and soy bean at the global level, and for wheat for major spring wheat producing countries. The impact of the new parametrisation, compared to the standard configuration, on the simulation of surface heat fluxes is largely an alteration of the partitioning between latent and sensible heat fluxes during the later part of the growing season. Further evaluation at the site level shows the model captures the seasonality of leaf area index and canopy height better than in standard JULES. However, this does not lead to an improvement in the simulation of sensible and latent heat fluxes. The performance of JULES-crop from both an earth system and crop yield model perspective is encouraging however, more effort is needed to develop the parameterisation of the model for specific applications. Key future model developments identified include the specification of the yield gap to enable better representation of the spatial variability in yield.
Variation in beliefs about ‘fracking’ between the UK and US
NASA Astrophysics Data System (ADS)
Evensen, Darrick; Stedman, Richard; O'Hara, Sarah; Humphrey, Mathew; Andersson-Hudson, Jessica
2017-12-01
In decision-making on the politically-contentious issue of unconventional gas development, the UK Government and European Commission are attempting to learn from the US experience. Although economic, environmental, and health impacts and regulatory contexts have been compared cross-nationally, public perceptions and their antecedents have not. We conducted similar online panel surveys of national samples of UK and US residents simultaneously in September 2014 to compare public perceptions and beliefs affecting such perceptions. The US sample was more likely to associate positive impacts with development (i.e. production of clean energy, cheap energy, and advancing national energy security). The UK sample was more likely to associate negative impacts (i.e. water contamination, higher carbon emissions, and earthquakes). Multivariate analyses reveal divergence cross-nationally in the relationship between beliefs about impacts and support/opposition—especially for beliefs about energy security. People who associated shale gas development with increased energy security in the UK were over three times more likely to support development than people in the US with this same belief. We conclude with implications for policy and communication, discussing communication approaches that could be successful cross-nationally and policy foci to which the UK might need to afford more attention in its continually evolving regulatory environment.
NASA Astrophysics Data System (ADS)
McGrane, Scott J.; Hutchins, Michael G.; Miller, James D.; Bussi, Gianbattista; Kjeldsen, Thomas R.; Loewenthal, Matt
2017-02-01
This paper presents the hydrological and water quality response from a series of extreme storm events that passed across the UK during the winter of 2013/2014, in an experimental catchment with a strong rural-urban gradient across four nested sub-catchment areas. The Ray catchment in the upper Thames basin, UK, was extensively monitored using in-situ, high-resolution (15 min) flow and water quality instrumentation. Dissolved oxygen, ammonium, turbidity and specific conductivity are used to characterise the water quality dynamics. The impact of the Swindon sewage treatment works (SSTW) on water chemistry at the catchment outlet is considerable. Hydrological and water-quality response varies considerably during the events, with the rural catchments exhibiting a much slower hydrological response compared to urban areas. A simple hydrological model (TETIS) was developed to provide insight into water sources in nested subcatchments, highlighting the disparity of the hydrological dynamics across contrasting land-uses during events. The variation in stormwater runoff sources impacts water quality signals with urban sites contributing to dilution dynamics in ammonium, whereas the more rural site experiences a peak in ammonium during the same event. Dissolved oxygen concentrations vary on a rural-urban gradient and experience a notable sag at the Water Eaton outlet (4.4 mg/l) during the events, that would have resulted in significant ecological harm had they occurred during the summer in warmer temperatures. The water-quality legacy of these storms in the wider context of the hydrological year is somewhat negligible, with markedly poorer water quality signals being observed during the summer months of 2014. Although ammonium concentrations during the events are elevated (above the 'good' status threshold under the WFD), higher values are observed during spring and summer months. The high flows actually appear to flush contaminants out of the Ray and its subcatchments, though the urban sites demonstrate a resupply dynamic during interim dry periods. Data suggest winter storms following dry spells in urban catchments cause some short-lived and spatially extensive deteriorations in water quality. More chronic effects, although prolonged, are only seen downstream of SSTW. These are indicative of capacity of infrastructure being reached, and from the data do not appear to be severe enough to cause ecological harm.
ERIC Educational Resources Information Center
Cole, Mike
2017-01-01
Critical Race Theory (CRT) has a relatively long history in the United States, from where it originated, dating back to the 1980s. Its presence in UK academic literature, however, is more recent, having surfaced in the first decade of the twenty-first century. I focus in this paper on developments in CRT in the UK from January 2012 to January…
Grover, D P; Zhou, J L; Frickers, P E; Readman, J W
2011-01-30
Sewage effluents are widely recognised as the main source of emerging contaminants, such as endocrine disrupting chemicals (EDCs) and pharmaceuticals in surface waters. A full-scale granular activated carbon (GAC) plant has been installed as an advanced technology for the removal of these contaminants, in a major sewage treatment works (STW) in South-West England as part of the UK National Demonstration Programme for EDCs. This study presented for the first time, an assessment of the impact of a recently commissioned, post-tertiary GAC plant in the removal of emerging contaminants in a working STW. Through regular sampling followed by solid-phase extraction and analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS), a significant reduction in the concentrations of steroidal estrogens was observed (>43-64%). In addition, significant reductions were observed for many of the pharmaceutical compounds such as mebeverine (84-99%), although the reduction was less dramatic for some of the more widely used pharmaceuticals analysed, including carbamazepine and propranolol (17-23%). Copyright © 2010 Elsevier B.V. All rights reserved.
Optimizaton of corrosion control for lead in drinking water using computational modeling techniques
Computational modeling techniques have been used to very good effect in the UK in the optimization of corrosion control for lead in drinking water. A “proof-of-concept” project with three US/CA case studies sought to demonstrate that such techniques could work equally well in the...
Maintenance Work, Maintenance Skills: The Case of a Major Water Company in the UK.
ERIC Educational Resources Information Center
Cooke, Fang Lee
2002-01-01
A case study of a British water company found that technological change had only a moderate impact on technical skills but increased the need for diagnostic and information technology skills for the maintenance of electronic equipment. Organizational restructuring increased requirements for functional flexibility and interpersonal skills.…
The subject paper describes a procedure for adjusting a risk model based upon a measure of personal exposure (the "UK personal exposure model") in order to attribute an expected rate of gastroenteritis among a group of swimmers to a mean recreational water quality value (enteroco...
Middleton, D R S; Watts, M J; Hamilton, E M; Fletcher, T; Leonardi, G S; Close, R M; Exley, K S; Crabbe, H; Polya, D A
2016-05-18
Chronic exposure to arsenic (As) in drinking water is an established cause of cancer and other adverse health effects. Arsenic concentrations >10 μg L(-1) were previously measured in 5% of private water supplies (PWS) in Cornwall, UK. The present study investigated prolongued exposure to As by measuring biomarkers in hair and toenail samples from 212 volunteers and repeated measurements of As in drinking water from 127 households served by PWS. Strong positive Pearson correlations (rp = 0.95) indicated stability of water As concentrations over the time period investigated (up to 31 months). Drinking water As concentrations were positively correlated with toenail (rp = 0.53) and hair (rp = 0.38) As concentrations - indicative of prolonged exposure. Analysis of washing procedure solutions provided strong evidence of the effective removal of exogenous As from toenail samples. Significantly higher As concentrations were measured in hair samples from males and smokers and As concentrations in toenails were negatively associated with age. A positive association between seafood consumption and toenail As and a negative association between home-grown vegetable consumption and hair As was observed for volunteers exposed to <1 As μg L(-1) in drinking water. These findings have important implications regarding the interpretation of toenail and hair biomarkers. Substantial variation in biomarker As concentrations remained unaccounted for, with soil and dust exposure as possible explanations.
Quantifying Preferential Flow and Seasonal Storage in an Unsaturated Fracture-Facial Domain
NASA Astrophysics Data System (ADS)
Nimmo, J. R.; Malek-Mohammadi, S.
2012-12-01
Preferential flow through deep unsaturated zones of fractured rock is hydrologically important to a variety of contaminant transport and water-resource issues. The unsaturated zone of the English Chalk Aquifer provides an important opportunity for a case study of unsaturated preferential flow in isolation from other flow modes. The chalk matrix has low hydraulic conductivity and stays saturated, owing to its fine uniform pores and the wet climate of the region. Therefore the substantial fluxes observed in the unsaturated chalk must be within fractures and interact minimally with matrix material. Price et al. [2000] showed that irregularities on fracture surfaces provide a significant storage capacity in the chalk unsaturated zone, likely accounting for volumes of water required to explain unexpected dry-season water-table stability during substantial continuing streamflow observed by Lewis et al. [1993] In this presentation we discuss and quantify the dynamics of replenishment and drainage of this unsaturated zone fracture-face storage domain using a modification of the source-responsive model of Nimmo [2010]. This model explains the processes in terms of two interacting flow regimes: a film or rivulet preferential flow regime on rough fracture faces, active on an individual-storm timescale, and a regime of adsorptive and surface-tension influences, resembling traditional diffuse formulations of unsaturated flow, effective mainly on a seasonal timescale. The modified model identifies hydraulic parameters for an unsaturated fracture-facial domain lining the fractures. Besides helping to quantify the unsaturated zone storage described by Price et al., these results highlight the importance of research on the topic of unsaturated-flow relations within a near-fracture-surface domain. This model can also facilitate understanding of mechanisms for reinitiation of preferential flow after temporary cessation, which is important in multi-year preferential flow through deep unsaturated zones [Pruess, 1999]. Lewis, M.A., H.K. Jones, D.M.J. Macdonald, M. Price, J.A. Barker, T.R. Shearer, A.J. Wesselink, and D.J. Evans (1993), Groundwater storage in British aquifers--Chalk, National Rivers Authority R&D Note, 169, Bristol, UK. Nimmo, J.R. (2010), Theory for Source-Responsive and Free-Surface Film Modeling of Unsaturated Flow, Vadose Zone Journal, 9(2), 295-306, doi:10.2136/vzj2009.0085. Price, M., R.G. Low, and C. McCann (2000), Mechanisms of water storage and flow in the unsaturated zone of the Chalk aquifer, Journal of Hydrology, 233(1-4), 54-71. Pruess, K. (1999), A mechanistic model for water seepage through thick unsaturated zones in fractured rocks of low matrix permeability, Water Resources Research, 35(4), 1039-1051.
Enhancing the Biodiversity of Ditches in Intensively Managed UK Farmland
Shaw, Rosalind F.; Johnson, Paul J.; Macdonald, David W.; Feber, Ruth E.
2015-01-01
Drainage ditches, either seasonally flooded or permanent, are commonly found on intensively managed lowland farmland in the UK. They are potentially important for wetland biodiversity but, despite their ubiquity, information on their biodiversity and management in the wider countryside is scarce. We surveyed 175 ditches for their physical and chemical characteristics, spatial connectivity, plant communities and aquatic invertebrates in an area of intensively managed farmland in Oxfordshire, UK and collected information on ditch management from farmer interviews. Water depth and shade had a small impact on the diversity of plant and invertebrate communities in ditches. Increased shade over the ditch channel resulted in reduced taxonomic richness of both channel vegetation and aquatic invertebrates and channel vegetation cover was lower at shaded sites. Invertebrate taxonomic richness was higher when water was deeper. Spatial connectivity had no detectable impact on the aquatic invertebrate or plant communities found in ditches. The number of families within the orders Ephemeroptera, Plecoptera and Trichoptera (EPT), which contain many pollution-sensitive species, declined with decreasing pH of ditch water. As time since dredging increased, the number of EPT families increased in permanent ditches but decreased in temporary ditches. Whether or not a ditch was in an agri-environment scheme had little impact on the reported management regime or biodiversity value of the ditch. Measures for increasing the amount of water in ditches, by increasing the water depth or promoting retention of water in ditches, could increase the biodiversity value of ditches in agricultural land. Some temporary ditches for specialised species should be retained. Reducing the amount of shade over narrow ditches by managing adjacent hedgerows is also likely to increase the species diversity of plant and invertebrate communities within the ditch. We recommend that to preserve or enhance the biodiversity value of ditches, and improve their ecosystem service delivery, management prescriptions for hedgerows adjacent to ditches should differ from those aimed at hedgerows only. PMID:26445146
Hydrogeochemical investigation of Küçük Menderes River coastal wetland, Selçuk-Izmir, Turkey
NASA Astrophysics Data System (ADS)
Somay, A. Melis; Gemici, Ünsal; Filiz, Sevki
2008-07-01
Küçük Menderes River forms a rich coastal wetland inside in the Selçuk plain. Three saline/brackish lakes, one swamp and Küçük Menderes River are these wetlands’ components. Alkaline-slightly alkaline type lakes are recharged from precipitation and karstic springs that discharge from marble-schist and marble-alluvium contacts in the northern and southern parts of the study area. Water types of the wetland are Na-Cl and Na-Ca-Mg-HCO3-Cl in both rainy and dry seasons. Both seawater intrusion and evaporation, as being the sources of the ions, justify the presence of Na-Cl, Na-SO4 and Cl-SO4, in the wetland water. Environmental isotopes were used to identify the relationship between wetland and groundwater in the Selçuk plain. The δ18O and δD composition of wetland area samples have changed between -6.42 to -4.56‰, and -36.40 to -23.80‰, respectively. The lakes and rivers are plotted on the mixing line by slope of 5.2 and these data indicate that wetland is affected from seawater intrusion. The recharge area that was sampled in order to compare the wetland has Ca-HCO3 water type with a neutral-slightly alkaline pH values and the main hydrogeochemical process is weathering the different types of silicates. Iron, manganese and selenium are the dominant minor ions due to the high biological activities and organic matters in the lakes. There are two contamination risks for this wetland: (1) waste disposal site and (2) water treatment plant where the purified waters are released into the river. EC, Al, As, Cd, Cu, Fe and Zn values exceed those of aquatic life standards. In the near future these sites will pose a danger for wetland wild life and surrounding irrigation water suppliers.
Enhancing the Biodiversity of Ditches in Intensively Managed UK Farmland.
Shaw, Rosalind F; Johnson, Paul J; Macdonald, David W; Feber, Ruth E
2015-01-01
Drainage ditches, either seasonally flooded or permanent, are commonly found on intensively managed lowland farmland in the UK. They are potentially important for wetland biodiversity but, despite their ubiquity, information on their biodiversity and management in the wider countryside is scarce. We surveyed 175 ditches for their physical and chemical characteristics, spatial connectivity, plant communities and aquatic invertebrates in an area of intensively managed farmland in Oxfordshire, UK and collected information on ditch management from farmer interviews. Water depth and shade had a small impact on the diversity of plant and invertebrate communities in ditches. Increased shade over the ditch channel resulted in reduced taxonomic richness of both channel vegetation and aquatic invertebrates and channel vegetation cover was lower at shaded sites. Invertebrate taxonomic richness was higher when water was deeper. Spatial connectivity had no detectable impact on the aquatic invertebrate or plant communities found in ditches. The number of families within the orders Ephemeroptera, Plecoptera and Trichoptera (EPT), which contain many pollution-sensitive species, declined with decreasing pH of ditch water. As time since dredging increased, the number of EPT families increased in permanent ditches but decreased in temporary ditches. Whether or not a ditch was in an agri-environment scheme had little impact on the reported management regime or biodiversity value of the ditch. Measures for increasing the amount of water in ditches, by increasing the water depth or promoting retention of water in ditches, could increase the biodiversity value of ditches in agricultural land. Some temporary ditches for specialised species should be retained. Reducing the amount of shade over narrow ditches by managing adjacent hedgerows is also likely to increase the species diversity of plant and invertebrate communities within the ditch. We recommend that to preserve or enhance the biodiversity value of ditches, and improve their ecosystem service delivery, management prescriptions for hedgerows adjacent to ditches should differ from those aimed at hedgerows only.
Annotated Bibliography of Water Optical Properties of Ocean Waters.
1982-05-01
24. Barrett, B. B. ( 1971 ). Cooperative Gulf of Mexico Estuarine Inventory and Study, Louisiana, Phase II, Hydrology and Phase III, Sedimentology...Assoc. U.K. (39), 227-238. Ambient light measurements to depths of 400 m. 35. Boulter, Jacques ( 1971 ). Photometric Sous-marine. Measures effectuees...Florida coastal water with a Hydroproducts transmissometer (550 nm). 41. Carder, Kendall L., G. F. Beardsley, Jr., and Hasong Pak ( 1971 ). Particle Size
CryoSat-2: From SAR to LRM (FBR) for quantitative precision comparison over identical sea state
NASA Astrophysics Data System (ADS)
Martin-Puig, Cristina; Ruffini, Giulio; Raney, R. Keith; Gommenginger, Christine
The use of Synthetic Aperture Radar (SAR) techniques in conventional altimetry—i.e., Delay Doppler Altimetry (DDA)—was first introduced by R.K. Raney in 1998 [1]. This technique provides an improved solution for water surface altimetry observations due to two major innova-tions: the addition of along track processing for increased resolution, and multi-look processing for improved SNR. Cryosat-2 (scheduled for launch 2010) will be the first satellite to operate a SAR altimetry mode. Although its main focus will be the cryosphere, this instrument will also be sporadically operative over water surfaces, thus provide an opportunity to test and refine the improved capabilities of DDA. Moreover, the work presented here is of interest to the ESA's Sentinel-3 mission. This mission will be devoted to the provision of operational oceanographic services within Global Monitoring for the Environment and Security (GMES), and will include a DDA altimeter on board. SAMOSA, an ESA funded project, has studied along the last two years the potentialities of advanced DDA over water surfaces. Its extension aims to better quantify the improvement of DDA over conventional altimetry for the characterization of water surfaces. Cryosat-2s altimeter (SIRAL) has three operating modes: the Low Resolution Mode (LRM), the SAR mode and the inSAR mode. The first two are of interest for the work to be done. In LRM the altimeter performs as a conventional pulse limited altimeter (PRF of 1970 Hz); in SAR mode the pulses are transmitted in bursts (64 pulses per burst). In the last, correlation between echoes is desired [1], thus the PRF within a burst is higher than in LRM (PRF of 17.8 KHz). After transmission the altimeter waits for the returns, and transmits the next burst (burst repetition frequency of 85.7 Hz). The previous acquisition modes will provide different data products: level 1 or full bit rate data (FBR), level 1b or multi-looked waveform data, and level 2 for evaluation or geophysical products. This paper is only addressing FBR data for LRM and SAR mode. In LRM the FBR data corresponds to echoes incoherently multi-looked on-board the satellite at a rate of 20Hz, while in SAR mode FBR corresponds to individual complex echoes (I and Q), telemetered before the IFFT block [2]. Given that CryoSat-2 operational modes are exclusive, one task within SAMOSA extension aims to reduce SAR FBR data such that it emulates LRM FBR data allowing for the quantitative comparison of the measurement precision over identical sea state. In working to this aim, three methodolo-gies were implemented in the SAMOSA contract, the results achieved and detailed discussions with JHU/APL identified a revised approach (to be implemented in the SAMOSA extension), which should allow the team to meet the task goal. The different approaches will be presented in this paper. ACKNOWLEDGEMENT The authors of this paper would like to acknowledge the European Space Agency for funding the work presented in this paper, with special attention to J. Benveniste and S. Dinardo (ESA); and the SAMOSA team: D. Cotton (SatOC; UK), L. Stenseng (DTU; DE) and P. Berry (DMU; UK) REFERENCES [1] R.K.Raney, The Delay/Doppler Radar Altimeter, IEEE Trans. Georsci. Remote Sensing, vol. 36, pp. 1578-1588, Sep 1998. [2] CryoSat Mission and Data Description, Doc No. CS-RP-ESA-SY-0059, 2007.
Groundwater Drought and Recovery: a Case Study from the United Kingdom
NASA Astrophysics Data System (ADS)
Peach, D.; McKenzie, A. A.; Bloomfield, J.
2012-12-01
An understanding of the processes leading to the onset, duration and end of hydrological droughts is necessary to help improve the management of stressed or scarce water resources during such periods. In particular, the role and use of groundwater during episodes of drought is crucially important, since groundwater can provide relatively resilient water supplies during early stages of drought but maybe highly susceptible to relatively persistent or sustained droughts. Nevertheless, groundwater is seldom considered in drought analyses, and compared with other types of hydrological drought there have been few studies to date. The few previous studies of groundwater droughts at catchment- and regional-scale have shown that catchment and aquifer characteristics exert a strong influence on the spatio-temporal development of groundwater droughts as water deficit propagates through the terrestrial water cycle. In this context, the relationships between hydrogeological heterogeneity, catchment engineering infrastructure (storage), and decisions related to water resource management during drought events all shape the evolution and consequences of groundwater droughts. Here we examine the evolution of a recent regionally significant two-year drought across the United Kingdom (UK) and use it to investigate these relationships. We identify the drivers, characterise the development and spatio-temporal extent of the groundwater drought. In particular, we focus on the unusually rapid end and recovery from drought during what would normally be a period of groundwater recession. The UK, and in particular southern England, relies extensively on groundwater for public water supply, agricultural and industrial use, as well as for sustaining river flows that are essential to ecosystem health. In normal years relatively consistent rainfall patterns prevail, recharging aquifers over winter when evapotranspiration is minimal. However, by March 2012 large parts of the southern UK had experienced accumulated rainfall deficiencies over 24 months or more. Such rainfall deficiencies could, on aver¬age, only be expected around once every 20 to 30 years. The rainfall deficiencies were disproportionately concentrated in the winter/spring periods leading to significant reductions in groundwater recharge over the winters of 2010-11 and particularly 2011-12. At it's height in March 2012 groundwater levels were at historically low levels with estimated overall storage in the Chalk aquifer, the principal aquifer in the UK, lower than at the same time in 1976, the previous benchmark drought for the UK. Natural base levels had been reached or closely approached at a number of index wells early in the hydrometric year and groundwater recession was expected to continue with the prospect of overall groundwater resources being comparable with, or below, the lowest in the last 100 years by the autumn of 2012. However, a significant change in weather in spring 2012 led to three months (April to June) of exceptional rainfall, mitigating the drought and leading to anomalous groundwater recharge at a time of year when soil moisture deficits are normally significant.
Chepulis, Lynne; Mearns, Gael; Hill, Shaunie; Wu, Jason Hy; Crino, Michelle; Alderton, Sarah; Jenner, Katharine
2018-02-07
To compare the nutritional content, serving size and taxation potential of supermarket beverages from four different Western countries. Cross-sectional analysis. Multivariate regression analysis and χ 2 comparisons were used to detect differences between countries. Supermarkets in New Zealand (NZ), Australia, Canada and the UK. Supermarket beverages in the following categories: fruit juices, fruit-based drinks, carbonated soda, waters and sports/energy drinks. A total of 4157 products were analysed, including 749 from NZ, 1738 from Australia, 740 from Canada and 930 from the UK. NZ had the highest percentage of beverages with sugar added to them (52 %), while the UK had the lowest (9 %, P8 % sugar) categories. There is substantial difference between countries in the mean energy, serving size and proportion of products eligible for fiscal sugar taxation. Current self-regulatory approaches used in these countries may not be effective to reduce the availability, marketing and consumption of sugar-sweetened beverages and subsequent intake of free sugars.
NASA Astrophysics Data System (ADS)
Thomas, Merryn; Partridge, Tristan; Harthorn, Barbara Herr; Pidgeon, Nick
2017-04-01
Shale gas and oil production in the US has increased rapidly in the past decade, while interest in prospective development has also arisen in the UK. In both countries, shale resources and the method of their extraction (hydraulic fracturing, or 'fracking') have been met with opposition amid concerns about impacts on water, greenhouse gas emissions, and health effects. Here we report the findings of a qualitative, cross-national deliberation study of public perceptions of shale development in UK and US locations not yet subject to extensive shale development. When presented with a carefully calibrated range of risks and benefits, participants' discourse focused on risks or doubts about benefits, and potential impacts were viewed as inequitably distributed. Participants drew on direct, place-based experiences as well as national contexts in deliberating shale development. These findings suggest that shale gas development already evokes a similar 'signature' of risk across the US and UK.
NASA Astrophysics Data System (ADS)
Dalgaard, T.; Bienkowski, J. F.; Bleeker, A.; Dragosits, U.; Drouet, J. L.; Durand, P.; Frumau, A.; Hutchings, N. J.; Kedziora, A.; Magliulo, V.; Olesen, J. E.; Theobald, M. R.; Maury, O.; Akkal, N.; Cellier, P.
2012-12-01
Improved management of nitrogen (N) in agriculture is necessary to achieve a sustainable balance between the production of food and other biomass, and the unwanted effects of N on water pollution, greenhouse gas emissions, biodiversity deterioration and human health. To analyse farm N-losses and the complex interactions within farming systems, efficient methods for identifying emissions hotspots and evaluating mitigation measures are therefore needed. The present paper aims to fill this gap at the farm and landscape scales. Six agricultural landscapes in Poland (PL), the Netherlands (NL), France (FR), Italy (IT), Scotland (UK) and Denmark (DK) were studied, and a common method was developed for undertaking farm inventories and the derivation of farm N balances, N surpluses and for evaluating uncertainty for the 222 farms and 11 440 ha of farmland included in the study. In all landscapes, a large variation in the farm N surplus was found, and thereby a large potential for reductions. The highest average N surpluses were found in the most livestock-intensive landscapes of IT, FR, and NL; on average 202 ± 28, 179 ± 63 and 178 ± 20 kg N ha-1 yr-1, respectively. All landscapes showed hotspots, especially from livestock farms, including a special UK case with large-scale landless poultry farming. Overall, the average N surplus from the land-based UK farms dominated by extensive sheep and cattle grazing was only 31 ± 10 kg N ha-1 yr-1, but was similar to the N surplus of PL and DK (122 ± 20 and 146 ± 55 kg N ha-1 yr-1, respectively) when landless poultry farming was included. We found farm N balances to be a useful indicator for N losses and the potential for improving N management. Significant correlations to N surplus were found, both with ammonia air concentrations and nitrate concentrations in soils and groundwater, measured during the period of N management data collection in the landscapes from 2007-2009. This indicates that farm N surpluses may be used as an independent dataset for validation of measured and modelled N emissions in agricultural landscapes. No significant correlation was found with N measured in surface waters, probably because of spatial and temporal variations in groundwater buffering and biogeochemical reactions affecting N flows from farm to surface waters. A case study of the development in N surplus from the landscape in DK from 1998-2008 showed a 22% reduction related to measures targeted at N emissions from livestock farms. Based on the large differences in N surplus between average N management farms and the most modern and N-efficient farms, it was concluded that additional N-surplus reductions of 25-50%, as compared to the present level, were realistic in all landscapes. The implemented N-surplus method was thus effective for comparing and synthesizing results on farm N emissions and the potentials of mitigation options. It is recommended for use in combination with other methods for the assessment of landscape N emissions and farm N efficiency, including more detailed N source and N sink hotspot mapping, measurements and modelling.
Demonstration Of A Green-blue Approach For A Strategic Management Of Urban Runoff.
NASA Astrophysics Data System (ADS)
Jonczyk, J. C.; Quinn, P. F.; Heidrich, O.; James, P.; Harris, N.; Dawson, R. J.; Pearson, D. J.
2016-12-01
With more than half of the world's population now living in cities, there is an increasing need to facilitate urban areas to be more sustainable and resilient to the impacts of extreme events such as surface water flooding. Traditionally, urban storm water is managed predominately through grey infrastructure such as sewer collection systems and flood walls, often with little consideration of the increased water utility costs or downstream flood risk. There is little collaboration between organisations and sectors on managing and mitigating the impacts of flooding at city level, with decisions made in silos. A 24-acre development zone is used as a case study to show how different sectors and organisations came to realise the multiple benefits of a blue-green, joined-up, site-wide approach to managing storm runoff. The Science Central development zone (http://www.newcastlesciencecentral.com/) is at the heart of the city and is jointly owned by Newcastle University and the Newcastle city council with an overall vision for innovation and urban sustainability. The masterplan was reviewed and agreed by the partners in 2016 to include a site-wide holistic conveyance of surface water through a series of measures across the site, and the commercial needs of the building plots were balanced with the need to manage the flood hazard. Uniquely, once constructed, the measures will be monitored to evaluate how they function and the multiple benefits they provide will also be evaluated. This will include monitoring water and air quality parameters, indicators of biodiversity and carbon capture through The Urban Observatory. The Urban Observatory (http://urbanobservatory.ac.uk/) is a research project based at Newcastle University that produces a data portal of open and scalable data from deployments of heterogeneous sensors and 3rd party data sources around the city. The site will also host a new national sustainable urban drainage research facility that will provide research infrastructure to carry out detailed experiments, with the aim of improving the evidence based for green-blue solutions. Science Central and its approach to surface runoff is to be an exemplar of a future, sustainable city with a vision to demonstrate that making space for water can provide a more liveable and thriving environment for all.
Oceans Apart: Using Stable Isotopes to Assess the Role of Fog in Two Semi-Arid Island Ecosystems
NASA Astrophysics Data System (ADS)
Schmitt, S.; Riveros-Iregui, D.; Hu, J.
2017-12-01
Fog is a significant hydrologic input in many tropical island systems, and is a water source particularly susceptible to the effects of global climate change. To better understand the role of fog as a hydrological input in two oceanic islands, we address two principal questions: 1) Do seasonal or extreme precipitation events lead to distinguishable differences in stable isotopic signatures of water inputs within and between sites and islands? 2) Does microclimatic zonation lead to distinguishable differences in isotopic signatures of meteoric inputs between different sites on a given island? To perform this analysis, meteoric water samples (fog, rain and throughfall) were collected over three sites (one windward and two leeward) and three field seasons in San Cristobal, Galapagos to ascertain the isotopic signature of each water balance input during different times of year. An additional field season of data in Ascension Island, UK, was also used to perform a comparative analysis between islands. A stable isotope mixing model was used to determine the relative proportion of surface water and groundwater that is composed of fog, and to demonstrate spatiotemporal patterns of recharge dynamics in each island system. Local meteoric water lines were generated for each site and over each field season to determine the source of hydrologic inputs (trade wind-generated orographic precipitation versus storm precipitation) and the role of locally recycled water in the overall water balance of each site. Our results will approximate potential changes in water inputs to San Cristobal and Ascension, respectively, that could be impacted by an increase in cloud base height or a change in weather patterns brought about by climate change.
Towards an estimation of water masses formation areas from SMOS-based TS diagrams
NASA Astrophysics Data System (ADS)
Klockmann, Marlene; Sabia, Roberto; Fernandez-Prieto, Diego; Donlon, Craig; Font, Jordi
2014-05-01
Temperature-Salinity (TS) diagrams emphasize the mutual variability of ocean temperature and salinity values, relating them to the corresponding density. Canonically used in oceanography, they provide a means to characterize and trace ocean water masses. In [1], a first attempt to estimate surface-layer TS diagrams based on satellite measurements has been performed, profiting from the recent availability of spaceborne salinity data. In fact, the Soil Moisture and Ocean Salinity (SMOS, [2]) and the Aquarius/SAC-D [3] satellite missions allow to study the dynamical patterns of Sea Surface Salinity (SSS) for the first time on a global scale. In [4], given SMOS and Aquarius salinity estimates, and by also using Sea Surface Temperature (SST) from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA, [5]) effort, experimental satellite-based TS diagrams have been routinely derived for the year 2011. They have been compared with those computed from ARGO-buoys interpolated fields, referring to a customised partition of the global ocean into seven regions, according to the water masses classification of [6]. In [7], moreover, besides using TS diagrams as a diagnostic tool to evaluate the temporal variation of SST and SSS (and their corresponding density) as estimated by satellite measurements, the emphasis was on the interpretation of the geographical deviations with respect to the ARGO baseline (aiming at distinguishing between the SSS retrieval errors and the additional information contained in the satellite data with respect to ARGO). In order to relate these mismatches to identifiable oceanographic structures and processes, additional satellite datasets of ocean currents, evaporation/precipitation fluxes, and wind speed have been super-imposed. Currently, the main focus of the study deals with the exploitation of these TS diagrams as a prognostic tool to derive water masses formation areas. Firstly, following the approach described in [8], the surface density flux (i.e., the change in density induced by surface heat and freshwater fluxes) is computed, characterizing how the buoyancy of a water parcel is being transformed, by increasing or decreasing its density. Afterwards, integrating over a certain time/space and deriving with respect to density, the formation (in Sv) of water masses themselves can be computed, pinpointing the range of SST and SSS in the TS diagrams where a specific water mass is formed. A geographical representation of these points, ultimately, allows to provide a relevant temporal series of the spatial extent of the water masses formation areas (in the specific test zones chosen). This can be then extended over challenging ocean regions, also evaluating the sensitivity of the performances to the datasets used. With this approach, known water masses can be identified and their formation traced in time and space. Longer time series will give further insights by helping to identify inter-annual water mass formation variability and trends in the TS/geographical domains. Future work aims at exploring additional datasets and at connecting the surface information to the vertical structure and to buoyancy-driven ocean circulation processes. References [1] Sabia, R., J. Ballabrera, G. Lagerloef, E. Bayler, M. Talone, Y. Chao, C. Donlon, D. Fernández-Prieto, J. Font, "Derivation of an Experimental Satellite-based T-S Diagram", In Proceedings of IGARSS '12 , Munich, Germany, pp. 5760-5763, 2012. [2] Font, J., A. Camps, A. Borges, M. Martín-Neira, J. Boutin, N. Reul, Y. H. Kerr, A. Hahne, and S. Mecklenburg, "SMOS: The challenging sea surface salinity measurement from space," Proceedings of the IEEE, vol. 98, pp. 649-665, 2010. [3] Le Vine, D.M.; Lagerloef, G.S.E.; Torrusio, S.E.; "Aquarius and Remote Sensing of Sea Surface Salinity from Space," Proceedings of the IEEE , vol.98, no.5, pp.688-703, May 2010, doi: 10.1109/JPROC.2010.2040550. [4] Sabia, R., M. Klockmann, D. Fernández-Prieto, C. Donlon, E. Bayler, J. Font, G. Lagerloef, "Satellite-based T/S Diagrams and Surface Ocean Water Masses", SMOS-Aquarius Science Workshop, Brest, France, April 2013. [5] Donlon, C. J., M. Martin, J. D. Stark, J. Roberts-Jones, E. Fiedler and W. Wimmer, "The Operational Sea Surface Temperature and Sea Ice analysis (OSTIA)", Remote Sensing of the Environment. doi: 10.1016/j.rse.2010.10.017 2011. [6] Emery, W. J., "Water Types and Water Masses", Ocean Circulation, Elsevier science, pp 1556-1567, 2003. [7] Sabia, R., M. Klockmann, C. Donlon, D. Fernández-Prieto, M. Talone, J. Ballabrera, "Satellite-based T-S Diagrams: a prospective diagnostic tool to trace ocean water masses", Living Planet Symposium 2013, Edinburgh, UK, September 2013. [8] Speer, K., E. Tzipermann, "Rates of Water Mass Transformation in the North Atlantic", Journal of Physical Oceanography, 22, 93 - 104, 1992.
Research and the problems of litter and medical wastes on the UK coastline.
Philipp, R; Pond, K; Rees, G
1997-01-01
Recent research has shown that recreational water and bathing beach quality are associated with injury, infection and personal well-being. Continued surveillance is essential to audit the environmental and associated health trends. In the Coastwatch UK project and since 1989, annual surveys each autumn have been undertaken during a two-week study period, into the extent of littering of the UK coastline. The Public Health Laboratory Service also collects data on the use of hepatitis B immunoglobulin. In these studies it is now possible to examine time trends. The findings are not reassuring. They help to justify present concern about the health effects of discarded litter and medical waste and fears that environmental degradation could lead to loss of income from tourism. In response, some health and local authorities have started public education programmes, supplying litter bins on or near bathing beaches, emptying them regularly and undertaking beach cleansing during the summer months. The UK government is also introducing new legislation that will require 6 mm fine mesh wire screens on all shore-based sewage outlets around the UK coastline. Continued monitoring is needed to assess the effectiveness of these interventions. The need for greater personal responsibility is particularly identified.
Fluids During Diagenesis and Sulfate Vein Formation in Sediments at Gale Crater, Mars
NASA Technical Reports Server (NTRS)
Schwenzer, S. P.; Bridges, J. C.; Weins, R. C.; Conrad, P. G.; Kelley, S. P.; Leveille, R.; Mangold, N.; Martin-Torres, J.; McAdam, A.; Newsom, H.;
2016-01-01
We model the fluids involved in the alteration processes recorded in the Sheep bed Member mudstones of Yellowknife Bay (YKB), Gale crater, Mars, as revealed by the Mars Science Laboratory Curiosity rover investigations. We compare the Gale crater waters with fluids modeled for shergottites, nakhlites, and the ancient meteorite ALH 84001, as well as rocks analyzed by the Mars Exploration rovers, and with terrestrial ground and surface waters. The aqueous solution present during sediment alteration associated with phyllosilicate formation at Gale was high in Na, K, and Si; had low Mg, Fe, and Al concentrations relative to terrestrial ground waters such as the Deccan Traps and other modeled Mars fluids; and had near neutral to alkaline pH. Ca and S species were present in the 10(exp -3) to 10(exp -2) concentration range. A fluid local to Gale crater strata produced the alteration products observed by Curiosity and subsequent evaporation of this ground water- type fluid formed impure sulfate- and silica-rich deposits veins or horizons. In a second, separate stage of alteration, partial dissolution of this sulfate-rich layer in Yellowknife Bay,or beyond, led to the pure sulfate veins observed in YKB. This scenario is analogous to similar processes identified at a terrestrial site in Triassic sediments with gypsum veins of the Mercia Mudstone Group in Watchet Bay, UK.
NASA Astrophysics Data System (ADS)
Menéndez José Luis, Marcos; Gómez José Luis, Sánchez; Campano Laura, López; Ortega Eduardo, García; Suances Andrés, Merino; González Sergio, Fernández; Salvador Estíbaliz, Gascón; González Lucía, Hermida
2015-04-01
In this study, we used a 28-day database corresponding to December, January and February of 2011/2012 and 2012/2013 campaigns to analyze cloud structure that produced precipitation in the Sierra Norte near Madrid, Spain. We used remote sensing measurements, both active type like the K-band Micro Rain Radar (MRR) and passive type like the Radiometrics MP-3000A multichannel microwave radiometer. Using reflectivity data from the MRR, we determined the important microphysical parameters of Ice Water Content (IWC) and its integrated value over the atmospheric column, or Ice Water Path (IWP). Among the measurements taken by the MP-3000A were Liquid Water Path (LWP) and Integrated Water Vapor (IWV). By representing these data together, sharp declines in LWP and IWV were evident, coincident with IWP increases. This result indicates the ability of a K-band radar to measure the amount of ice in the atmospheric column, simultaneously revealing the Wegener-Bergeron-Findeisen mechanism. We also used a Present Weather Sensor (VPF-730; Biral Ltd., Bristol, UK) to determine the type and amount of precipitation at the surface. With these data, we used regression equations to establish the relationship between visibility and precipitation intensity. In addition, through theoretical precipitation visibility-intensity relationships, we estimated the type of crystal, degree of accretion (riming), and moisture content of fallen snow crystals.
UK Environmental Prediction - integration and evaluation at the convective scale
NASA Astrophysics Data System (ADS)
Fallmann, Joachim; Lewis, Huw; Castillo, Juan Manuel; Pearson, David; Harris, Chris; Saulter, Andy; Bricheno, Lucy; Blyth, Eleanor
2016-04-01
It has long been understood that accurate prediction and warning of the impacts of severe weather requires an integrated approach to forecasting. For example, high impact weather is typically manifested through various interactions and feedbacks between different components of the Earth System. Damaging high winds can lead to significant damage from the large waves and storm surge along coastlines. The impact of intense rainfall can be translated through saturated soils and land surface processes, high river flows and flooding inland. The substantial impacts on individuals, businesses and infrastructure of such events indicate a pressing need to understand better the value that might be delivered through more integrated environmental prediction. To address this need, the Met Office, NERC Centre for Ecology & Hydrology and NERC National Oceanography Centre have begun to develop the foundations of a coupled high resolution probabilistic forecast system for the UK at km-scale. This links together existing model components of the atmosphere, coastal ocean, land surface and hydrology. Our initial focus has been on a 2-year Prototype project to demonstrate the UK coupled prediction concept in research mode. This presentation will provide an update on UK environmental prediction activities. We will present the results from the initial implementation of an atmosphere-land-ocean coupled system and discuss progress and initial results from further development to integrate wave interactions. We will discuss future directions and opportunities for collaboration in environmental prediction, and the challenges to realise the potential of integrated regional coupled forecasting for improving predictions and applications.
NASA Astrophysics Data System (ADS)
Lo, L.; Chuang, C. K.; Wei, K. Y.; Shen, C. C.; Mii, H. S.; Chang, Y. P.
2017-12-01
In this study, we reconstruct surface and upper thermocline seawater temperatures by using planktonic foraminifera Globigerinoides sacculifer and Neogloboquadrina deutertrei in the southern Western Pacific Warm Pool (S-WPWP, ODP Site 1115B, 9o11'S, 151o34'E, water depth 1149 m) during past 2.2-1.1 million years (Ma). Significant S-WPWP surface warming in both glacial and interglacial periods during 1.86-1.55 Ma is accompanied with gradual upper thermocline cooling. S-WPWP sea surface temperature dropped 2.1oC from 1.50-1.21 Ma but upper thermocline temperature further decreased 1.1oC at this time period. WPWP expansion event is also supported by vertical foraminiferal Mg/Ca-derived temperature profile records in the central WPWP (ODP Site 806, Ford et al. 2015). Although foraminiferal Mg/Ca-derived temperature records from Eastern Equatorial Pacific suggests long-term cooling trend (Wara et al. 2005), alkenone undersaturation index (UK'37)-inferred surface temperature records suggest 1oC warming during 2.0-1.5 Ma (Fedorov et al. 2013). We argue that seasonal expansion of WPWP may be attributable to the meridional thermocline gradient increasing (Martinez-Garcia et al. 2010) during 2.0-1.5 Ma. Long-term extent variability of WPWP could have impact on cross-equatorial energy transportation and meridional precipitation belt movements (Lo et al., 2014).
NASA Astrophysics Data System (ADS)
El Araby, Mahmoud; Odling, Noelle; Clark, Roger; West, Jared
2010-05-01
Borehole water levels fluctuate in response to deformation of the surrounding aquifer caused by surface loading due to barometric pressure or strain caused by Earth and ocean tides. The magnitude and nature of this response mainly depend on the hydraulic properties of the aquifer and overlying units and borehole design. Thus water level responses reflect the effectiveness of a confining unit as a protective layer against aquifer contamination (and therefore groundwater vulnerability) and to potential aquifer recharge/discharge zones. In this study, time series of borehole water levels and barometric pressure are being investigated using time series analysis and signal processing techniques with the aim of developing a methodology for assessing recharge/discharge distribution and groundwater vulnerability in the confined/semi-confined part of the Chalk aquifer in East Yorkshire, UK. The chalk aquifer in East Yorkshire is an important source for industrial and domestic water supply. The aquifer water quality is threatened by surface pollution particularly by nitrates from agricultural fertilizers. The confined/semi-confined part of this aquifer is covered by various types of superficial deposits resulting in a wide range of the aquifer's degree of confinement. A number of boreholes have been selected for monitoring to cover all these various types of confining units. Automatic pressure transducers are installed to record water levels and barometric pressure measurements at each borehole on 15 minutes recording intervals. In strictly confined aquifers, borehole water level response to barometric pressure is an un-drained instantaneous response and is a constant fraction of the barometric pressure changes. This static confined constant is called the barometric efficiency which can be estimated simply by the slope of a regression plot of water levels versus barometric pressure. However, in the semi confined aquifer case this response is lagged due to water movement between the aquifer and the confining layer. In this case the static constant barometric efficiency is not applicable and the response is represented by a barometric response function which reflects the timing and frequency of the barometric pressure loading. In this study, the barometric response function is estimated using de-convolution techniques both in the time domain (least squares regression de-convolution) and in the frequency domain (discrete Fourier transform de-convolution). In order to estimate the barometric response function, borehole water level fluctuations due to factors other than barometric pressure should be removed (de-trended) as otherwise they will mask the response relation of interest. It is shown from the collected borehole data records that the main four factors other than barometric pressure contribute to borehole water level fluctuations. These are the rainfall recharge, Earth tides, sea tides and pumping activities close to the borehole location. Due to the highly variable nature of the UK weather, rainfall recharge shows a wide variation throughout the winter and summer seasons. This gives a complicated recharge signal over a wide range of frequencies which must be de-trended from the borehole water level data in order to estimate the barometric response function. Methods for removing this recharge signal are developed and discussed. Earth tides are calculated theoretically at each borehole location taking into account oceanic loading effects. Ocean tide effects on water levels fluctuations are clear for the boreholes located close to the coast. A Matlab code has been designed to calculate and de-trend the periodic fluctuations in borehole water levels due to Earth and ocean tides using the least squares regression technique based on a sum of sine and cosine fitting model functions. The program results have been confirmed using spectral analysis techniques.
UK Atlantic Margin Environmental Survey: Introduction and overview of bathyal benthic ecology
NASA Astrophysics Data System (ADS)
Bett, Brian J.
2001-05-01
The recent expansion of the Oil and Gas Industry in to the deep waters of the UK Atlantic Frontier prompted the industry and its regulator to reappraise the needs and means of environmental monitoring. In concert, deep-sea academics, specialist contractors, the regulator and the Industry, through the Atlantic Frontier Environmental Network (AFEN), devised and implemented a large-scale environmental survey of the deep waters to the north and west of Scotland. The AFEN-funded survey was carried out during the summers of 1996 and 1998, and involved two steps; an initial sidescan sonar mapping of the survey areas, followed up with direct seabed investigations by coring and photography. This contribution deals with the latter step. Seabed samples were collected to assess sediment type, organic content, heavy metals, hydrocarbons and macrobenthos. Photographic and video observations were employed to provide both 'routine' seabed assessments and to investigate particular sidescan features of note. Although essentially intended as a 'baseline' environmental survey, anthropogenic impacts are already evident throughout the areas surveyed. Indications of the effects of deep-sea trawling were frequently encountered (seabed trawl marks and areas of disturbed sediments), being present in almost all of the areas studied and extending to water depths in excess of 1000 m. Evidence of localised contamination of the seabed by drilling muds was also detected, though background hydrocarbon contamination is predominantly of terrestrial origin or derived from shipping. The benthic ecology of the UK Atlantic Margin is dominated by the marked differences in the hydrography of the Faroe-Shetland Channel (FSC) and the Rockall Trough (RT). Comparatively warm North Atlantic Water is common to both areas; however, in the FSC, cold (subzero) waters occupy the deeper parts of the channel (>600 m). The extreme thermal gradient present on the West Shetland Slope has a substantial influence on the distribution and diversity of the macrobenthos. While there is continuous variation in the fauna with depth, warm and cold water faunas are nonetheless quite distinct. The boundary region, centred on 400 m water depth, may be best characterised as an ecotone, having a mixed warm and cold water fauna with a distinctly enhanced diversity. The Wyville-Thomson Ridge largely prevents the cold waters of the deep FSC from entering the RT (they certainly do not influence the areas of the Malin/Hebrides Slope assessed during the survey). Consequently, the deep-water faunas north and south of the ridge are highly distinct. There is also a very marked difference in the diversity of the two faunas: diversity declines with depth in the FSC but increases with depth in the RT. The distribution of macrobenthos in the RT is largely continuous with depth, with little indication of local variations but some evidence of enhanced rates of change at around 1200 m, possibly associated with the presence of Labrador Sea Water. Other observations made during the course of the survey include: (a) the occurrence of sponge dominated communities (' ostebund') at mid-slope depths (ca. 500 m) north and west of Shetland; (b) the discovery of a population of sediment surface dwelling enteropneusts associated with a sandy contourite deposit at the base of the West Shetland Slope (ca. 900 m); (c) the widespread and abundant occurrence of phytodetritus in the RT but not the FSC; and (d) the discovery of the ' Darwin Mounds' at ca. 1000 m in the northern RT, a field of numerous, small seabed mounds that support significant growths of the coral Lophelia pertusa. These mounds also have 'acoustically visible tails' with dense populations of xenophyophores ( Syringammina fragilissima), a species found to be common elsewhere in the RT.
O'Neill, Antonia; Gupta, Bhaskar Sen; Phillips, Debra H
2014-06-01
The use of seaweed fertilisers in sports green maintenance has become a common practice across the globe due to its image as an "eco-friendly" alternative to chemical fertilisers. The aim of this study was to characterise the risk of human exposure to arsenic (As), via dermal absorption, from golfing activities on a private golf course in the UK, where As contaminated seaweed fertiliser (~100mg/kg d.wt.) is applied. This was fulfilled by, 1) determining As concentrations in shallow soils with GIS geo-statistical analysis, 2) measuring As concentrations from an on-site borehole groundwater well, and (3) developing a risk assessment calculation for golfing activities based on field and questionnaire data. Total As concentrations in shallow soils were less than the UK threshold for domestic soils, however, frequent and sustained dermal contact between site-users and surface soil attributed to a maximum carcinogenic risk value of 2.75×10(-4), which is in the upper limit of the acceptable risk range. Arsenic concentrations in underlying groundwater exceeded the WHO's permissible drinking water standard, demonstrating the risk of groundwater contamination following the application of seaweed fertiliser to golf course soils. This is the first risk study on dermal As absorption via the application of a seaweed fertiliser. Copyright © 2014 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Martinez Vicente, V.; Simis, S. G. H.; Alegre, R.; Land, P. E.; Groom, S. B.
2013-09-01
Un-supervised hyperspectral remote-sensing reflectance data (<15 km from the shore) were collected from a moving research vessel. Twodifferent processing methods were compared. The results were similar to concurrent Aqua-MODIS and Suomi-NPP-VIIRS satellite data.
Findlay, Helen S; Artioli, Yuri; Moreno Navas, Juan; Hennige, Sebastian J; Wicks, Laura C; Huvenne, Veerle A I; Woodward, E Malcolm S; Roberts, J Murray
2013-09-01
Cold-water coral (CWC) reefs are recognized as ecologically and biologically significant areas that generate habitats and diversity. The interaction between hydrodynamics and CWCs has been well studied at the Mingulay Reef Complex, a relatively shallow area of reefs found on the continental shelf off Scotland, UK. Within 'Mingulay Area 01' a rapid tidal downwelling of surface waters, brought about as an internal wave, is known to supply warmer, phytoplankton-rich waters to corals growing on the northern flank of an east-west trending seabed ridge. This study shows that this tidal downwelling also causes short-term perturbations in the inorganic carbon (CT ) and nutrient dynamics through the water column and immediately above the reef. Over a 14 h period, corresponding to one semi-diurnal tidal cycle, seawater pH overlying the reef varied by ca. 0.1 pH unit, while pCO2 shifted by >60 μatm, a shift equivalent to a ca. 25 year jump into the future, with respect to atmospheric pCO2 . During the summer stratified period, these downwelling events result in the reef being washed over with surface water that has higher pH, is warmer, nutrient depleted, but rich in phytoplankton-derived particles compared to the deeper waters in which the corals sit. Empirical observations, together with outputs from the European Regional Shelf Sea Ecosystem Model, demonstrate that the variability that the CWC reefs experience changes through the seasons and into the future. Hence, as ocean acidification and warming increase into the future, the downwelling event specific to this site could provide short-term amelioration of corrosive conditions at certain times of the year; however, it could additionally result in enhanced detrimental impacts of warming on CWCs. Natural variability in the CT and nutrient conditions, as well as local hydrodynamic regimes, must be accounted for in any future predictions concerning the responses of marine ecosystems to climate change. © 2013 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Witham, Claire; Vieno, Massimo; Schmidt, Anja; Aspinall, Willy; Braban, Christine; Hort, Matthew; Loughlin, Sue
2015-04-01
In response to the recent introduction of large gas-rich volcanic eruptions to the UK National Risk Register a modelling project has been conducted to improve our understanding of potential impacts to the UK from such an eruption on Iceland. A precautionary reasonable worst case eruption scenario based on the 1783-4 Laki eruption has been modelled 80 times using two different atmospheric chemistry and transport models (NAME and EMEP4UK) over 10 years of meteorology. The results provide information on the range of concentrations of sulphur dioxide gas (SO2), sulphate aerosol (SO4) and some halogen species that might be experienced in the UK during such an eruption and the likelihood of key thresholds being exceeded and over what durations. Data for the surface and for a range of key flight levels have been produced. In this presentation we will evaluate the ambient mass concentrations of SO2 and SO4 that could be experienced during and following such an eruption, as well as the likelihood of key health concentration thresholds being exceeded, and the maximum duration that levels could persist for. The prevailing meteorological conditions are the key influence on which parts of the North Atlantic and European region are affected at any time. The results demonstrate that the UK is unlikely to be affected by week after week of significantly elevated concentrations; rather there will a number of short (hours to days) pollution episodes where concentrations would be elevated above Moderate and High air quality index levels at the surface. This pattern fits with the generally changeable nature of the weather in the UK. Consecutive exceedance durations are longer for sulphate aerosol than SO2, and can be particularly lengthy in the low air quality index levels (1-2 weeks), which may be of relevance to health impact assessments. This work represents a detailed initial study but has not explored the full range of such an eruption. Nonetheless, the results from this project are informing cross-Government work to improve the understanding of the risk to the UK from an effusive gas-rich eruption in Iceland. This includes the production of area-specific impact assessments for sectors including health, aviation and environment. "This work is distributed under the Creative Commons Attribution 3.0 Unported License together with an author copyright. This license does not conflict with the regulations of the Crown Copyright."
Wild, S R; Jones, K C
1995-01-01
This paper presents the first attempt to quantify the production, cycling, storage and loss of PAHs in the UK environment. Over 53 000 tonnes of sigmaPAHs (sum of 12 individual compounds) are estimated to reside in the contemporary UK environment, with soil being the major repository. If soils at contaminated sites are included, this estimate increases dramatically. Emission of PAHs to the UK atmosphere from primary combustion sources are estimated to be greater than 1000 tonnes sigmaPAHs per annum, with over 95% coming from domestic coal combustion, unregulated fires and vehicle emissions. It is estimated that approximately 210 tonnes of sigmaPAH are delivered to terrestrial surfaces each year via atmospheric deposition. Therefore, inputs of PAHs to the UK atmosphere outweigh the outputs by a factor of over 4. This may be explained by enhanced particulate deposition near point sources, PAH degradation in the atmosphere and transport away from the UK with prevailing winds. Disposal of waste residues is estimated to contribute a further 1000 tonnes of sigmaPAH per year to the terrestrial environment. It is illustrated that the use of creosote has the potential to release considerable quantities of PAHs to the UK environment. Temporal trends in PAH cycling are then considered. There is good evidence to suggest that air concentrations and fluxes to the UK surface are now lower than at any time throughout this century. Nonetheless, the UK sigmaPAH burden is still increasing at the present time, principally through retention by soils. However, there are marked differences in the behaviour of individual compounds: there is evidence, for example, that phenanthrene concentrations in soils have declined since the 1960s, although soil concentrations of benzo[a]pyrene and other heavier PAHs have continued to increase through this century. Volatilisation of low molecular weight PAHs accumulated in soils over previous decades may be making an important contribution to the current atmospheric burden. The major uncertainties identified by data on this budget are: (1) the lack of PAH concentrations in some environmental matrices; (2) the possible importance of contaminated soils as a major repository and source of PAHs; (3) the lack of emission data (especially vapour phase releases) for some PAH sources; (4) the importance of biodegradation and volatilisation as loss mechanisms for low molecular weight PAHs in soils; and (5) the importance of creosote use in the PAH cycle.
Handley-Sidhu, Stephanie; Mullan, Thomas K.; Grail, Quentin; Albadarneh, Malek; Ohnuki, Toshihiko; Macaskie, Lynne E.
2016-01-01
Anthropogenic radionuclides contaminate a range of environments as a result of nuclear activities, for example, leakage from waste storage tanks/ponds (e.g. Hanford, USA or Sellafield sites, UK) or as a result of large scale nuclear accidents (e.g. Chernobyl, Ukraine or Fukushima, Japan). One of the most widely applied remediation techniques for contaminated waters is the use of sorbent materials (e.g. zeolites and apatites). However, a key problem at nuclear contaminated sites is the remediation of radionuclides from complex chemical environments. In this study, biogenic hydroxyapatite (BHAP) produced by Serratia sp. bacteria was investigated for its potential to remediate surrogate radionuclides (Sr2+ and Co2+) from environmentally relevant waters by varying pH, salinity and the type and concentration of cations present. The sorption capacity of the BHAP for both Sr2+ and Co2+ was higher than for a synthetically produced hydroxyapatite (HAP) in the solutions tested. BHAP also compared favorably against a natural zeolite (as used in industrial decontamination) for Sr2+ and Co2+ uptake from saline waters. Results confirm that hydroxyapatite minerals of high surface area and amorphous calcium phosphate content, typical for biogenic sources, are suitable restoration or reactive barrier materials for the remediation of complex contaminated environments or wastewaters. PMID:26988070
NASA Astrophysics Data System (ADS)
Handley-Sidhu, Stephanie; Mullan, Thomas K.; Grail, Quentin; Albadarneh, Malek; Ohnuki, Toshihiko; Macaskie, Lynne E.
2016-03-01
Anthropogenic radionuclides contaminate a range of environments as a result of nuclear activities, for example, leakage from waste storage tanks/ponds (e.g. Hanford, USA or Sellafield sites, UK) or as a result of large scale nuclear accidents (e.g. Chernobyl, Ukraine or Fukushima, Japan). One of the most widely applied remediation techniques for contaminated waters is the use of sorbent materials (e.g. zeolites and apatites). However, a key problem at nuclear contaminated sites is the remediation of radionuclides from complex chemical environments. In this study, biogenic hydroxyapatite (BHAP) produced by Serratia sp. bacteria was investigated for its potential to remediate surrogate radionuclides (Sr2+ and Co2+) from environmentally relevant waters by varying pH, salinity and the type and concentration of cations present. The sorption capacity of the BHAP for both Sr2+ and Co2+ was higher than for a synthetically produced hydroxyapatite (HAP) in the solutions tested. BHAP also compared favorably against a natural zeolite (as used in industrial decontamination) for Sr2+ and Co2+ uptake from saline waters. Results confirm that hydroxyapatite minerals of high surface area and amorphous calcium phosphate content, typical for biogenic sources, are suitable restoration or reactive barrier materials for the remediation of complex contaminated environments or wastewaters.
Water quality trading opportunities in two sub-watersheds in the northern Lake Okeechobee watershed.
Corrales, Juliana; Naja, G Melodie; Bhat, Mahadev G; Miralles-Wilhelm, Fernando
2017-07-01
For decades, the increase of nutrient enrichment has threatened the ecological integrity and economic sustainability of many rivers, lakes, and coastal waters, including Lake Okeechobee, the second largest freshwater lake in the contiguous United States. Water quality trading programs have been an area of active development to both, reduce nutrient pollution and minimize abatement costs. The objective of this study was to apply a comprehensive modeling framework, integrating a hydrologic-water quality model with an economic model, to assess and compare the cost-effectiveness of a water quality trading program over a command-and-control approach in order to reduce phosphorus loadings to Lake Okeechobee. The Upper Kissimmee (UK) and Taylor Creek/Nubbin Slough (TCNS) sub-watersheds, identified as major sources of total phosphorus (TP) loadings to the lake, were selected for this analysis. The effect of different caps on the market potential was assessed while considering four factors: the least-cost abatement solutions, credit prices, potential cost savings, and credit supply and demand. Hypothetical trading scenarios were also developed, using the optimal caps selected for the two sub-watersheds. In both sub-watersheds, a phosphorus credit trading program was less expensive than the conventional command-and-control approach. While attaining cost-effectiveness, keeping optimal credit prices, and fostering market competition, phosphorus reduction targets of 46% and 32% were selected as the most appropriate caps in the UK and TCNS sub-watersheds, respectively. Wastewater treatment facilities and urban areas in the UK, and concentrated animal feeding operations in the TCNS sub-watershed were identified as potential credit buyers, whereas improved pastures were identified as the major credit sellers in both sub-watersheds. The estimated net cost savings resulting from implementing a phosphorus trading program in the UK and TCNS sub-watersheds were 76% ($ 34.9 million per year) and 45% ($ 3.2 million per year), respectively. It is important to note that the realization of the environmental and economic benefits of this market-based alternative is also contingent on other important factors, such as the market structure, the specific program rules, the risk perception, and the education and outreach to develop trusted relationships among regulatory agencies, the public sector, and other stakeholders. Nevertheless, this research provided the foundation for stakeholders to better understand whether water quality trading has the potential to work in the Lake Okeechobee watershed and to facilitate the development of a pilot program. Copyright © 2017 Elsevier Ltd. All rights reserved.
"Upstream Thinking": the catchment management approach of a water provider
NASA Astrophysics Data System (ADS)
Grand-Clement, E.; Ross, M.; Smith, D.; Anderson, K.; Luscombe, D.; Le Feuvre, N.; Brazier, R. E.
2012-04-01
Human activities have large impacts on water quality and provision. Water companies throughout the UK are faced with the consequences of poor land management and need to find appropriate solutions to decreasing water quality. This is particularly true in the South West of England, where 93% of the drinking water is sourced from rivers and reservoirs: large areas of drained peatlands (i.e. Exmoor and Dartmoor National Parks) are responsible for a significant input of dissolved organic carbon (DOC) discolouring the water, whilst poorly managed farming activities can lead to diffuse pollution. Alongside the direct environmental implications, poor water quality is partly increasing water treatment costs and will drive significant future investment in additional water treatment, with further repercussions on customers. This highlights the need for water companies throughout the UK, and further afield, to be more involved in catchment management. "Upstream Thinking" is South West Water's (SWW) approach to catchment management, where working with stakeholders to improve water quality upstream aims to avoid increasingly costly solutions downstream. This approach has led the company to invest in two major areas of work: (1) The Farmland programme where problematic farm management practices and potential solutions are identified, typically 40% of the required investment is then offered in exchange for a legal undertaking to maintain the new farm assets in good condition for 25 years; (2) The Mires programme which involves heavy investment in peatland restoration through the blocking of open ditches in order to improve water storage and quality in the long term. From these two projects, it has been clear that stakeholder involvement of groups such as local farmers, the Westcountry Rivers Trust, the Exmoor National Park Authority, the Environment Agency, Natural England and the Exmoor Society is essential, first because it draws in catchment improvement expertise which is not directly held within the company, and second because it shows how local communities and groups are considered and valued by the company. Monitoring changes and providing a solid scientific base is also undertaken to prove the concept and justify any investment. The work carried out so far has highlighted that SWW's collaborative approach to catchment management is changing the relationship between private water suppliers in the UK and stakeholders or groups having an impact on water quality. This results in a progressive move from a situation where the polluter has to pay, to rewarding providers of clean water instead. The value of ecosystem payments of this kind is being discussed with the appropriate authorities (i.e. Natural England, and the Department for Environment, Food and Rural Affairs) so that it can form part of ensuring sustainable water supplies in future, with all the environmental and ecological benefits of clear raw waters in rivers, lakes and streams.
U.K. Flooding Captured by NASA Spacecraft
2014-02-19
This image acquired by NASA Terra spacecraft depicts the high water levels and flooding along the Thames River west of London as record-breaking rains covered the United Kingdom in January and February.
A method of estimating in-stream residence time of water in rivers
NASA Astrophysics Data System (ADS)
Worrall, F.; Howden, N. J. K.; Burt, T. P.
2014-05-01
This study develops a method for estimating the average in-stream residence time of water in a river channel and across large catchments, i.e. the time between water entering a river and reaching a downstream monitoring point. The methodology uses river flow gauging data to integrate Manning's equation along a length of channel for different percentile flows. The method was developed and tested for the River Tees in northern England and then applied across the United Kingdom (UK). The study developed methods to predict channel width and main channel length from catchment area. For an 818 km2 catchment with a channel length of 79 km, the in-stream residence time at the 50% exceedence flow was 13.8 h. The method was applied to nine UK river basins and the results showed that in-stream residence time was related to the average slope of a basin and its average annual rainfall. For the UK as a whole, the discharge-weighted in-stream residence time was 26.7 h for the median flow. At median flow, 50% of the discharge-weighted in-stream residence time was due to only 6 out of the 323 catchments considered. Since only a few large rivers dominate the in-stream residence time, these rivers will dominate key biogeochemical processes controlling export at the national scale. The implications of the results for biogeochemistry, especially the turnover of carbon in rivers, are discussed.
Performance of a large building rainwater harvesting system.
Ward, S; Memon, F A; Butler, D
2012-10-15
Rainwater harvesting is increasingly becoming an integral part of the sustainable water management toolkit. Despite a plethora of studies modelling the feasibility of the utilisation of rainwater harvesting (RWH) systems in particular contexts, there remains a significant gap in knowledge in relation to detailed empirical assessments of performance. Domestic systems have been investigated to a limited degree in the literature, including in the UK, but there are few recent longitudinal studies of larger non-domestic systems. Additionally, there are few studies comparing estimated and actual performance. This paper presents the results of a longitudinal empirical performance assessment of a non-domestic RWH system located in an office building in the UK. Furthermore, it compares actual performance with the estimated performance based on two methods recommended by the British Standards Institute - the Intermediate (simple calculations) and Detailed (simulation-based) Approaches. Results highlight that the average measured water saving efficiency (amount of mains water saved) of the office-based RWH system was 87% across an 8-month period, due to the system being over-sized for the actual occupancy level. Consequently, a similar level of performance could have been achieved using a smaller-sized tank. Estimated cost savings resulted in capital payback periods of 11 and 6 years for the actual over-sized tank and the smaller optimised tank, respectively. However, more detailed cost data on maintenance and operation is required to perform whole life cost analyses. These findings indicate that office-scale RWH systems potentially offer significant water and cost savings. They also emphasise the importance of monitoring data and that a transition to the use of Detailed Approaches (particularly in the UK) is required to (a) minimise over-sizing of storage tanks and (b) build confidence in RWH system performance. Copyright © 2012 Elsevier Ltd. All rights reserved.
Combined evaluation of optical and microwave satellite dataset for soil moisture deficit estimation
NASA Astrophysics Data System (ADS)
Srivastava, Prashant K.; Han, Dawei; Islam, Tanvir; Singh, Sudhir Kumar; Gupta, Manika; Gupta, Dileep Kumar; Kumar, Pradeep
2016-04-01
Soil moisture is a key variable responsible for water and energy exchanges from land surface to the atmosphere (Srivastava et al., 2014). On the other hand, Soil Moisture Deficit (or SMD) can help regulating the proper use of water at specified time to avoid any agricultural losses (Srivastava et al., 2013b) and could help in preventing natural disasters, e.g. flood and drought (Srivastava et al., 2013a). In this study, evaluation of Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) and soil moisture from Soil Moisture and Ocean Salinity (SMOS) satellites are attempted for prediction of Soil Moisture Deficit (SMD). Sophisticated algorithm like Adaptive Neuro Fuzzy Inference System (ANFIS) is used for prediction of SMD using the MODIS and SMOS dataset. The benchmark SMD estimated from Probability Distributed Model (PDM) over the Brue catchment, Southwest of England, U.K. is used for all the validation. The performances are assessed in terms of Nash Sutcliffe Efficiency, Root Mean Square Error and the percentage of bias between ANFIS simulated SMD and the benchmark. The performance statistics revealed a good agreement between benchmark and the ANFIS estimated SMD using the MODIS dataset. The assessment of the products with respect to this peculiar evidence is an important step for successful development of hydro-meteorological model and forecasting system. The analysis of the satellite products (viz. SMOS soil moisture and MODIS LST) towards SMD prediction is a crucial step for successful hydrological modelling, agriculture and water resource management, and can provide important assistance in policy and decision making. Keywords: Land Surface Temperature, MODIS, SMOS, Soil Moisture Deficit, Fuzzy Logic System References: Srivastava, P.K., Han, D., Ramirez, M.A., Islam, T., 2013a. Appraisal of SMOS soil moisture at a catchment scale in a temperate maritime climate. Journal of Hydrology 498, 292-304. Srivastava, P.K., Han, D., Rico-Ramirez, M.A., Al-Shrafany, D., Islam, T., 2013b. Data fusion techniques for improving soil moisture deficit using SMOS satellite and WRF-NOAH land surface model. Water Resources Management 27, 5069-5087. Srivastava, P.K., Han, D., Rico-Ramirez, M.A., O'Neill, P., Islam, T., Gupta, M., 2014. Assessment of SMOS soil moisture retrieval parameters using tau-omega algorithms for soil moisture deficit estimation. Journal of Hydrology 519, 574-587.
Mapping coastal sea level at high resolution with radar interferometry: the SWOT Mission
NASA Astrophysics Data System (ADS)
Fu, L. L.; Chao, Y.; Laignel, B.; Turki, I., Sr.
2017-12-01
The spatial resolution of the present constellation of radar altimeters in mapping two-dimensional sea surface height (SSH) variability is approaching 100 km (in wavelength). At scales shorter than 100 km, the eddies and fronts are responsible for the stirring and mixing of the ocean, especially important in the various coastal processes. A mission currently in development will make high-resolution measurement of the height of water over the ocean as well as on land. It is called Surface Water and Ocean Topography (SWOT), which is a joint mission of US NASA and French CNES, with contributions from Canada and UK. SWOT will carry a pair of interferometry radars and make 2-dimensional SSH measurements over a swath of 120 km with a nadir gap of 20 km in a 21-day repeat orbit. The synthetic aperture radar of SWOT will make SSH measurement at extremely high resolution of 10-70 m. SWOT will also carry a nadir looking conventional altimeter and make 1-dimensional SSH measurements along the nadir gap. The temporal sampling varies from 2 repeats per 21 days at the equator to more than 4 repeats at mid latitudes and more than 6 at high latitudes. This new mission will allow a continuum of fine-scale observations from the open ocean to the coasts, estuaries and rivers, allowing us to investigate a number of scientific and technical questions in the coastal and estuarine domain to assess the coastal impacts of regional sea level change, such as the interaction of sea level with river flow, estuary inundation, storm surge, coastal wetlands, salt water intrusion, etc. As examples, we will illustrate the potential impact of SWOT to the studies of the San Francisco Bay Delta, and the Seine River estuary, etc. Preliminary results suggest that the SWOT Mission will provide fundamental data to map the spatial variability of water surface elevations under different hydrodynamic conditions and at different scales (local, regional and global) to improve our knowledge of the complex physical processes in the coastal and estuarine systems in response to global sea level changes.
Environmental impacts of chocolate production and consumption in the UK.
Konstantas, Antonios; Jeswani, Harish K; Stamford, Laurence; Azapagic, Adisa
2018-04-01
This study evaluates life cycle environmental impacts associated with chocolate products made and consumed in the UK. The paper focuses on three representative chocolate products occupying 90% of the market: 'moulded chocolate', 'chocolate countlines' and 'chocolates in bag'. The impacts were estimated using life cycle assessment (LCA) as a tool and following the ReCiPe impact assessment method. The water footprint was also considered. For example, the global warming potential ranges between 2.91 and 4.15 kg CO 2 eq., primary energy demand from 30 to 41 MJ and the water footprint, including water stress, from 31 to 63 l per kilogram of chocolate. The raw materials are the major hotspot across all impact categories for all three product types, followed by the chocolate production process and packaging. The raw material impacts are mainly due to milk powder, cocoa derivatives, sugar and palm oil. The sensitivity analysis shows that the results for global warming potential are sensitive to land-use change (LUC) associated with cocoa production, increasing the impact of the chocolate products by three to four times if LUC is involved. The improvement opportunities targeting the key contributing stages suggest that GWP of chocolates could be reduced by 14%-19%. Chocolate countlines have the highest contribution to the total impacts at the UK level (37%-43%), followed by chocolates in bag (28%-33%). Moulded chocolates and other chocolate confectionary make up the rest of the impacts, with a roughly equal share each. Chocolate consumption in the UK contributes 4.7% to the primary energy consumption and 2.4% to the GHG emissions from the whole food and drink sector. The results of this work will be of interest to policy makers, chocolate producers and consumers, helping them to make more informed decisions towards sustainable production and consumption of chocolate products. Copyright © 2018 Elsevier Ltd. All rights reserved.
Neal, C; House, W A; Leeks, G J; Whitton, B A; Williams, R J
2000-05-05
This paper presents an overview of the water quality functioning of eastern UK rivers draining into the North Sea. It summarises the results of three special issues of Science of the Total Environment and related work and complements a companion bibliography (Neal and Turner, 2000, this volume). The rivers are described in straightforward broad terms, and the reader is guided via the bibliography to the special volumes for the detailed findings. The water quality is shown to be highly variable over space and time. The changes over the past 300 years reflect first the transition from a rural society to the major impact of the industrial revolution and subsequently to one of the worlds' most successful environmental cleanups. The present water quality reflects the relative impacts of diffuse agricultural sources, urban and industrial point source discharges together with background inputs associated with geology: all these can be modified by within-river processes associated with physical mixing, biology and inorganic reactions. The work is set within the context of water quality, modelling and flux outputs to the North Sea and contemporary and future environmental research and management needs. A range of environmental impact studies is included. The detailed information is now available on a major and easily accessible database.
Sinha, Sangita; Rappu, Pekka; Lange, S. C.; Mäntsälä, Pekka; Zalkin, Howard; Smith, Janet L.
1999-01-01
The yabJ gene in Bacillus subtilis is required for adenine-mediated repression of purine biosynthetic genes in vivo and codes for an acid-soluble, 14-kDa protein. The molecular mechanism of YabJ is unknown. YabJ is a member of a large, widely distributed family of proteins of unknown biochemical function. The 1.7-Å crystal structure of YabJ reveals a trimeric organization with extensive buried hydrophobic surface and an internal water-filled cavity. The most important finding in the structure is a deep, narrow cleft between subunits lined with nine side chains that are invariant among the 25 most similar homologs. This conserved site is proposed to be a binding or catalytic site for a ligand or substrate that is common to YabJ and other members of the YER057c/YjgF/UK114 family of proteins. PMID:10557275
Developing a new global network of river reaches from merged satellite-derived datasets
NASA Astrophysics Data System (ADS)
Lion, C.; Allen, G. H.; Beighley, E.; Pavelsky, T.
2015-12-01
In 2020, the Surface Water and Ocean Topography satellite (SWOT), a joint mission of NASA/CNES/CSA/UK will be launched. One of its major products will be the measurements of continental water extent, including the width, height, and slope of rivers and the surface area and elevations of lakes. The mission will improve the monitoring of continental water and also our understanding of the interactions between different hydrologic reservoirs. For rivers, SWOT measurements of slope must be carried out over predefined river reaches. As such, an a priori dataset for rivers is needed in order to facilitate analysis of the raw SWOT data. The information required to produce this dataset includes measurements of river width, elevation, slope, planform, river network topology, and flow accumulation. To produce this product, we have linked two existing global datasets: the Global River Widths from Landsat (GRWL) database, which contains river centerline locations, widths, and a braiding index derived from Landsat imagery, and a modified version of the HydroSHEDS hydrologically corrected digital elevation product, which contains heights and flow accumulation measurements for streams at 3 arcsecond spatial resolution. Merging these two datasets requires considerable care. The difficulties, among others, lie in the difference of resolution: 30m versus 3 arseconds, and the age of the datasets: 2000 versus ~2010 (some rivers have moved, the braided sections are different). As such, we have developed custom software to merge the two datasets, taking into account the spatial proximity of river channels in the two datasets and ensuring that flow accumulation in the final dataset always increases downstream. Here, we present our preliminary results for a portion of South America and demonstrate the strengths and weaknesses of the method.
The CREW intercomparison of SEVIRI cloud retrievals
NASA Astrophysics Data System (ADS)
Hamann, U.; Walther, A.; Bennartz, R.; Thoss, A.; Meirink, J. M.; Roebeling, R.
2012-12-01
About 70% of the earth's surface is covered with clouds. They strongly influence the radiation balance and the water cycle of the earth. Hence the detailed monitoring of cloud properties - such as cloud fraction, cloud top temperature, cloud particle size, and cloud water path - is important to understand the role of clouds in the weather and the climate system. The remote sensing with passive sensors is an essential mean for the global observation of the cloud parameters, but is nevertheless challenging. This presentation focuses on the inter-comparison and validation of cloud physical properties retrievals from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) onboard METEOSAT. For this study we use retrievals from 12 state-of-art algorithms (Eumetsat, KNMI, NASA Langley, NASA Goddard, University Madison/Wisconsin, DWD, DLR, Meteo-France, KMI, FU Berlin, UK MetOffice) that are made available through the common database of the CREW (Cloud Retrieval Evaluation Working) group. Cloud detection, cloud top phase, height, and temperature, as well as optical properties and water path are validated with CLOUDSAT, CALIPSO, MISR, and AMSR-E measurements. Special emphasis is given to challenging retrieval conditions. Semi-transparent clouds over the earth's surface or another cloud layer modify the measured brightness temperature and increase the retrieval uncertainty. The consideration of the three-dimensional radiative effects is especially important for large viewing angles and broken cloud fields. Aerosols might be misclassified as cloud and may increase the retrieval uncertainty, too. Due to the availability of the high number of sophisticated retrieval datasets, the advantages of different retrieval approaches can be examined and suggestions for future retrieval developments can be made. We like to thank Eumetsat for sponsoring the CREW project including this work.nstitutes that participate in the CREW project.
NASA Astrophysics Data System (ADS)
Bhuiyan, M. A. E.; Nikolopoulos, E. I.; Anagnostou, E. N.
2017-12-01
Quantifying the uncertainty of global precipitation datasets is beneficial when using these precipitation products in hydrological applications, because precipitation uncertainty propagation through hydrologic modeling can significantly affect the accuracy of the simulated hydrologic variables. In this research the Iberian Peninsula has been used as the study area with a study period spanning eleven years (2000-2010). This study evaluates the performance of multiple hydrologic models forced with combined global rainfall estimates derived based on a Quantile Regression Forests (QRF) technique. In QRF technique three satellite precipitation products (CMORPH, PERSIANN, and 3B42 (V7)); an atmospheric reanalysis precipitation and air temperature dataset; satellite-derived near-surface daily soil moisture data; and a terrain elevation dataset are being utilized in this study. A high-resolution, ground-based observations driven precipitation dataset (named SAFRAN) available at 5 km/1 h resolution is used as reference. Through the QRF blending framework the stochastic error model produces error-adjusted ensemble precipitation realizations, which are used to force four global hydrological models (JULES (Joint UK Land Environment Simulator), WaterGAP3 (Water-Global Assessment and Prognosis), ORCHIDEE (Organizing Carbon and Hydrology in Dynamic Ecosystems) and SURFEX (Stands for Surface Externalisée) ) to simulate three hydrologic variables (surface runoff, subsurface runoff and evapotranspiration). The models are forced with the reference precipitation to generate reference-based hydrologic simulations. This study presents a comparative analysis of multiple hydrologic model simulations for different hydrologic variables and the impact of the blending algorithm on the simulated hydrologic variables. Results show how precipitation uncertainty propagates through the different hydrologic model structures to manifest in reduction of error in hydrologic variables.
Activation of hip prostheses in high energy radiotherapy and resultant dose to nearby tissue.
Keehan, Stephanie; Smith, Ryan L; Millar, Jeremy; Esser, Max; Taylor, Michael L; Lonski, Peta; Kron, Tomas; Franich, Rick D
2017-03-01
High energy radiotherapy can produce contaminant neutrons through the photonuclear effect. Patients receiving external beam radiation therapy to the pelvis may have high-density hip prostheses. Metallic materials such as those in hip prostheses, often have high cross-sections for neutron interaction. In this study, Thackray (UK) prosthetic hips have been irradiated by 18 MV radiotherapy beams to evaluate the additional dose to patients from the activation products. Hips were irradiated in- and out-of field at various distances from the beam isocenter to assess activation caused in-field by photo-activation, and neutron activation which occurs both in and out-of-field. NaI(Tl) scintillator detectors were used to measure the subsequent gamma-ray emissions and their half-lives. High sensitivity Mg, Cu, P doped LiF thermoluminescence dosimeter chips (TLD-100H) were used to measure the subsequent dose at the surface of a prosthesis over the 12 h following an in-field irradiation of 10,000 MU to a hip prosthesis located at the beam isocenter in a water phantom. 53 Fe, 56 Mn, and 52 V were identified within the hip following irradiation by radiotherapy beams. The dose measured at the surface of a prosthesis following irradiation in a water phantom was 0.20 mGy over 12 h. The dose at the surface of prostheses irradiated to 200 MU was below the limit of detection (0.05 mGy) of the TLD100H. Prosthetic hips are activated by incident photons and neutrons in high energy radiotherapy, however, the dose resulting from activation is very small. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.
Charlesworth, Susanne M; Beddow, Jamie; Nnadi, Ernest O
2017-06-21
Pervious Paving Systems (PPS) are part of a sustainable approach to drainage in which excess surface water is encouraged to infiltrate through their structure, during which potentially toxic elements, such as metals and hydrocarbons are treated by biodegradation and physical entrapment and storage. However, it is not known where in the PPS structure these contaminants accumulate, which has implications for environmental health, particularly during maintenance, as well as consequences for the recycling of material from the PPS at the end-of-life. A 1 m³ porous asphalt (PA) PPS test rig was monitored for 38 months after monthly additions of road sediment (RS) (367.5 g in total) and unused oil (430 mL in total), characteristic of urban loadings, were applied. Using a rainfall simulator, a typical UK rainfall rate of 15 mm/h was used to investigate its efficiency in dealing with contamination. Water quality of the effluent discharged from the rig was found to be suitable for discharge to most environments. On completion of the monitoring, a core was taken down through its surface, and samples of sediment and aggregate were taken. Analysis showed that most of the sediment remained in the surface course, with metal levels lower than the original RS, but higher than clean, unused aggregate or PA. However, even extrapolating these concentrations to 20 years' worth of in-service use (the projected life of PPS) did not suggest their accumulation would present an environmental pollution risk when carrying out maintenance of the pavement and also indicates that the material could be recycled at end-of-life.
NASA Astrophysics Data System (ADS)
Srivastava, Prashant K.; Petropoulos, George P.; Gupta, Manika; Islam, Tanvir
2015-04-01
Soil Moisture Deficit (SMD) is a key variable in the water and energy exchanges that occur at the land-surface/atmosphere interface. Monitoring SMD is an alternate method of irrigation scheduling and represents the use of the suitable quantity of water at the proper time by combining measurements of soil moisture deficit. In past it is found that LST has a strong relation to SMD, which can be estimated by MODIS or numerical weather prediction model such as WRF (Weather Research and Forecasting model). By looking into the importance of SMD, this work focused on the application of Artificial Neural Network (ANN) for evaluating its capabilities towards SMD estimation using the LST data estimated from MODIS and WRF mesoscale model. The benchmark SMD estimated from Probability Distribution Model (PDM) over the Brue catchment, Southwest of England, U.K. is used for all the calibration and validation experiments. The performances between observed and simulated SMD are assessed in terms of the Nash-Sutcliffe Efficiency (NSE), the Root Mean Square Error (RMSE) and the percentage of bias (%Bias). The application of the ANN confirmed a high capability WRF and MODIS LST for prediction of SMD. Performance during the ANN calibration and validation showed a good agreement between benchmark and estimated SMD with MODIS LST information with significantly higher performance than WRF simulated LST. The work presented showed the first comprehensive application of LST from MODIS and WRF mesoscale model for hydrological SMD estimation, particularly for the maritime climate. More studies in this direction are recommended to hydro-meteorological community, so that useful information will be accumulated in the technical literature domain for different geographical locations and climatic conditions. Keyword: WRF, Land Surface Temperature, MODIS satellite, Soil Moisture Deficit, Neural Network
Charlesworth, Susanne M.; Beddow, Jamie; Nnadi, Ernest O.
2017-01-01
Pervious Paving Systems (PPS) are part of a sustainable approach to drainage in which excess surface water is encouraged to infiltrate through their structure, during which potentially toxic elements, such as metals and hydrocarbons are treated by biodegradation and physical entrapment and storage. However, it is not known where in the PPS structure these contaminants accumulate, which has implications for environmental health, particularly during maintenance, as well as consequences for the recycling of material from the PPS at the end-of-life. A 1 m3 porous asphalt (PA) PPS test rig was monitored for 38 months after monthly additions of road sediment (RS) (367.5 g in total) and unused oil (430 mL in total), characteristic of urban loadings, were applied. Using a rainfall simulator, a typical UK rainfall rate of 15 mm/h was used to investigate its efficiency in dealing with contamination. Water quality of the effluent discharged from the rig was found to be suitable for discharge to most environments. On completion of the monitoring, a core was taken down through its surface, and samples of sediment and aggregate were taken. Analysis showed that most of the sediment remained in the surface course, with metal levels lower than the original RS, but higher than clean, unused aggregate or PA. However, even extrapolating these concentrations to 20 years’ worth of in-service use (the projected life of PPS) did not suggest their accumulation would present an environmental pollution risk when carrying out maintenance of the pavement and also indicates that the material could be recycled at end-of-life. PMID:28635641
NASA Astrophysics Data System (ADS)
Płuciennik-Koropczuk, Ewelina
2014-09-01
Increased production and consumption of drugs influences the pollution pharmaceuticals. Recent years have seen a significant increase in the consumption of non-prescription medicines, among which, are a large group of non-steroidal anti-inflammatory drugs (NSAIDs). Research conducted in Poland and abroad showed the presence of NSAIDs, both in treated wastewater in surface waters and drinking waters. One of the most frequently detected drugs in the environment is diclofenac, belongs to NSAID. Its concentration in surface waters range from 9 to 3363 ng/L. Traditional wastewater treatment plants are not specialized enough in removing the pharmaceuticals and their metabolites, and with purified wastewater are introduced into surface waters. Diclofenac concentrations in treated wastewater range from 0.29 to 2.5 μg/L, the average removal efficiency is about 40%. Wzrost produkcji i spożycia leków wpływa na zanieczyszczenie środowiska farmaceutykami. W ostatnich latach zaobserwowano zdecydowany wzrost spożycia leków dostępnych bez recepty, wśród których znaczną grupę stanowią niesteroidowe leki przeciwzapalne (NLPZ). Badania prowadzone na świecie i w Polsce wykazały obecność niesteroidowych leków przeciwzapalnych zarówno w ściekach oczyszczonych, w wodach powierzchniowych oraz w wodach pitnych. Jednym z najczęściej wykrywanych leków w środowisku jest diklofenak należący NLPZ. Jego stężenia w wodach powierzchniowych wynoszą od 9 do 3633 ng/dm3. Tradycyjne układy technologiczne oczyszczania nie eliminują zupełnie farmaceutyków i ich metabolitów i wraz ze ściekami oczyszczonymi są one wprowadzane do wód powierzchniowych. Stężenia diklofenaku w ściekach oczyszczonych wynoszą od 0,29 do 2,5 μg/dm3, a średnia skuteczność usuwania jest na poziomie ok 40%. Należy zaznaczyć, że dane te nie odzwierciedlają stanu rzeczywistego, gdyż badania są prowadzone wyrywkowo. W 2013 r. Komisja Europejska w dyrektywie Parlamentu Europejskiego i Rady (2013/39/EU) w zakresie substancji priorytetowych w dziedzinie polityki wodnej, umieściła na liście obserwacyjnej trzy substancje farmaceutyczne, wśród których wymieniany jest diklofenak. Ciągle jednak nie ustalono limitów dotyczących wprowadzania substancji farmaceutycznych do środowiska.
Genetic and management approaches to boost UK wheat yields by ameliorating water deficits.
Dodd, Ian C; Whalley, W R; Ober, Eric S; Parry, M A J
2011-11-01
Faced with the challenge of increasing global food production, there is the need to exploit all approaches to increasing crop yields. A major obstacle to boosting yields of wheat (an important staple in many parts of the world) is the availability and efficient use of water, since there is increasing stress on water resources used for agriculture globally, and also in parts of the UK. Improved soil and crop management and the development of new genotypes may increase wheat yields when water is limiting. Technical and scientific issues concerning management options such as irrigation and the use of growth-promoting rhizobacteria are explored, since these may allow the more efficient use of irrigation. Fundamental understanding of how crops sense and respond to multiple abiotic stresses can help improve the effective use of irrigation water. Experiments are needed to test the hypothesis that modifying wheat root system architecture (by increasing root proliferation deep in the soil profile) will allow greater soil water extraction thereby benefiting productivity and yield stability. Furthermore, better knowledge of plant and soil interactions and how below-ground and above-ground processes communicate within the plant can help identify traits and ultimately genes (or alleles) that will define genotypes that yield better under dry conditions. Developing new genotypes will take time and, therefore, these challenges need to be addressed now.
Nutrient cycles in agricultural systems at sub-catchment scale within the UK and China
NASA Astrophysics Data System (ADS)
Bellarby, Jessica; Surridge, Ben; Haygarth, Philip M.; Lai, Xin; Zhang, Guilong; Song, Xiaolong; Zhou, Jianbin; Meng, Fanqiao; Shen, Jianbo; Rahn, Clive; Smith, Laurence; Burke, Sean
2015-04-01
Diffuse water pollution from agriculture (DWPA) represents a significant challenge in both the UK and China. The UK has developed policies and practices which seek to mitigate DWPA, yet the risks and adverse impacts of DWPA remain widespread. In contrast, China's past priorities have largely focussed on food security, with an emphasis on increasing food production through high fertiliser application rates with little attention being paid to enhanced nutrient export from land to water and to air. This has contributed to severe environmental problems which are only now beginning to be recognised and addressed. We have prepared nutrient balances (phosphorus and nitrogen) in contrasting agricultural production systems at sub-catchment scale within China and the UK. These draw from a variety of sources ranging from general yearly statistics collected by the respective government to farm surveys. Our aim is to use the resulting nutrient balances to underpin the sharing of knowledge and innovation to mitigate DWPA in both nations. In the UK, the case studies focus on the three Demonstration Test Catchment locations, covering a range of livestock and arable production systems across England. Here, the high frequency monitoring of phosphorus river loads enables the cross-validation of the simple nutrient budget approaches applied in this study. In China, our case studies span kiwi orchard, fruit and vegetable solar greenhouse systems, double cropped rice-wheat and wheat-maize production systems. Substantial differences in nutrient stocks and flows exist between individual production systems both across and within the two countries. These differences will be expressed along the source-mobilisation-delivery-impact continuum that underpins our budgets for both phosphorus and nitrogen. We will present the phosphorus cycles of some case studies and highlight their challenges and relevance at sub-catchment scale. Based on our nutrient budgets, general recommendations can be formulated to mitigate DWPA from farm to policy levels.
Evaluation of the thermodynamic properties of hydrated metal oxide nanoparticles by INS techniques
DOE Office of Scientific and Technical Information (OSTI.GOV)
Spencer, Elinor; Ross, Dr. Nancy; Parker, Stewart F.
2013-01-01
In this contribution we will present a detailed methodology for the elucidation of the following aspects of the thermodynamic properties of hydrated metal oxide nanoparticles from high-resolution, low-temperature inelastic neutron scattering (INS) data: (i) the isochoric heat capacity and entropy of the hydration layers both chemi- and physisorbed to the particle surface; (ii) the magnetic contribution to the heat capacity of the nanoparticles. This will include the calculation of the vibrational density of states (VDOS) from the raw INS spectra, and the subsequent extraction of the thermodynamic data from the VDOS. This technique will be described in terms of amore » worked example namely, cobalt oxide (Co3O4 and CoO). To complement this evaluation of the physical properties of metal oxide nanoparticle systems, we will emphasise the importance of high-resolution, high-energy INS for the determination of the structure and dynamics of the water species, namely molecular (H2O) and dissociated water (OH, hydroxyl), confined to the oxide surfaces. For this component of the chapter we will focus on INS investigations of hydrated isostructural rutile (a-TiO2) and cassiterite (SnO2) nanoparticles. We will complete this discussion of nanoparticle analysis by including an appraisal of the INS instrumentation employed in such studies with particular focus on TOSCA [ISIS, Rutherford Appleton Laboratory (RAL), U.K.] and the newly developed spectrometer SEQUOIA [SNS, Oak Ridge National Laboratory (ORNL), U.S.A].« less
Wave Tank Studies of Phase Velocities of Short Wind Waves
NASA Astrophysics Data System (ADS)
Ermakov, S.; Sergievskaya, I.; Shchegolkov, Yu.
Wave tank studies of phase velocities of short wind waves have been carried out using Ka-band radar and an Optical Spectrum Analyser. The phase velocities were retrieved from measured radar and optical Doppler shifts, taking into account measurements of surface drift velocities. The dispersion relationship was studied in centimetre (cm)- and millimetre(mm)-scale wavelength ranges at different fetches and wind speeds, both for a clean water surface and for water covered with surfactant films. It is ob- tained that the phase velocities do not follow the dispersion relation of linear capillary- gravity waves, increasing with fetch and, therefore, depending on phase velocities of dominant decimetre (dm)-centimetre-scale wind waves. One thus can conclude that nonlinear cm-mm-scale harmonics bound to the dominant wind waves and propagat- ing with the phase velocities of the decimetric waves are present in the wind wave spectrum. The resulting phase velocities of short wind waves are determined by re- lation between free and bound waves. The relative intensity of the bound waves in the spectrum of short wind waves is estimated. It is shown that this relation depends strongly on the surfactant concentration, because the damping effect due to films is different for free and bound waves; this results to changes of phase velocities of wind waves in the presence of surfactant films. This work was supported by MOD, UK via DERA Winfrith (Project ISTC 1774P) and by RFBR (Project 02-05-65102).
NASA Astrophysics Data System (ADS)
Wimmer, Werenfrid
2016-08-01
The Infrared Sea surface temperature Autonomous Radiometer (ISAR) was developed to provide reference data for the validation of satellite Sea Surface Temperature at the Skin interface (SSTskin) temperature data products, particularly the Advanced Along Track Scanning Radiometer (AATSR). Since March 2004 ISAR instruments have been deployed nearly continuously on ferries crossing the English Channel and the Bay of Biscay, between Portsmouth (UK) and Bilbao/Santander (Spain). The resulting twelve years of ISAR data, including an individual uncertainty estimate for each SST record, are calibrated with traceability to national standards (National Institute of Standards and Technology, USA (NIST) and National Physical Laboratory, Teddigton, UK (NPL), Fiducial Reference Measurements for satellite derived surface temperature product validation (FRM4STS)). They provide a unique independent in situ reference dataset against which to validate satellite derived products. We present results of the AATSR validation, and show the use of ISAR fiducial reference measurements as a common traceable validation data source for both AATSR and Sea and Land Surface Temperature Radiometer (SLSTR). ISAR data were also used to review performance of the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) Sea Surface Temperature (SST) analysis before and after the demise of ESA Environmental Satellite (Envisat) when AATSR inputs ceased This demonstrates use of the ISAR reference data set for validating the SST climatologies that will bridge the data gap between AATSR and SLSTR.
Towards Sustainable Water Quality In Estuarine Impoundments: The Current State.
NASA Astrophysics Data System (ADS)
Wright, J.; Worrall, F.
Several estuarine impoundment schemes have been built or are proposed in the UK and worldwide. The impounding of estuaries is currently a popular approach to urban regeneration in the UK. By creation of an aesthetically pleasing amenity impound- ment, including the drowning of "unsightly" tidal mud flats, it is hoped that prestige development will be encouraged in the estuarine area. Impounding fundamentally alters the dynamics of estuaries, with consequences in terms of sedimentation patterns and rates, and water quality. The SIMBA Project at- tempts to understand the controls on water quality in impoundments, with a view to- wards long term and sustainable high water quality through good barrage design and management practice. Detailed water quality surveys have been carried out on a total of 79 dates on the Tees, Tawe, Wansbeck and Blyth estuaries. Water quality parameters which have been determined are pH, Eh, dissolved oxygen (DO), biochemical oxygen demand (BOD), conductivity, transparency, suspended solids, alkalinity, temperature, nutri- ents (nitrate+nitrite, ammonium and orthophosphate), and a large range of dissolved metals. Statistical analyses are used to demonstrate the major controls on water qual- ity in impoundments. A distinction is made between total tidal exclusion (freshwater) systems, in which water quality is primarily influenced by external/catchment factors, and partial tidal exclusion systems, in which water quality is processed internally. This internal processing is due to density stratification creating compartments of saline wa- ter in contact with oxygen demanding sediments and isolated from the atmosphere, which leads to conditions of low DO and changes in redox conditions which may lead to release of metals and phosphate from the sediment.
Sustaining water resources in South East England
NASA Astrophysics Data System (ADS)
Rodda, John C.
2006-07-01
The South East of England is one of the driest regions of the UK and it is also one of the most densely populated. As a consequence the available water resource per head of population is about half of the figure used by the World Bank to indicate that a country is suffering water stress. The South East Plan, prepared by the South East England Regional Assembly, proposes to increase the population of the region by about 1 million by 2026. This paper considers the ability of the Region's water resources to cope with this growth.
NASA Astrophysics Data System (ADS)
Hannam, Jacqueline; Vanguelova, Elena; West, Vicky
2017-04-01
The Woodland Carbon Code is a voluntary standard for woodland creation projects in the UK. Carbon sequestration resulting from certified projects will contribute directly to the UK's national targets for reducing emissions of greenhouse gases (GHG). Whilst this is concerned primarily with above ground capture there is little empirical evidence of the longer term carbon sequestration potential of soils under this land use change in the UK. We present preliminary results from a resurvey of 20 sites originally sampled as part of the soil survey of England and Wales. It includes soil carbon stocks assessed within the soil profile (up to 1m depth) where sites have been converted to forestry in the last 40 years. The small number of sites (n=20) and high variability in soil type, forest type and original land use prevented detailed analysis between these different factors, but overall there was an increase in carbon concentration in the whole profile, driven primarily by an increase the surface organic layers. For all sites combined there was no significant difference in the C stocks between the two survey periods. The increase in carbon stock in the surface organic horizons tended to be offset by a decrease in the mineral subsoils (specifically in Brown Earth soils) primarily as a result of bulk density changes. There are presently insufficient measured data from a range of UK climate, land-use and soil type conditions to quantify with confidence soil C changes during afforestation. This is partly because of the difficulties of detecting relatively slow changes in spatially heterogeneous soils and also obtaining good examples of sites that have undergone documented land use change. Reviewing results from all ongoing afforestation projects in the UK will provide better quantification of the C sequestration potential of forest soils to be accounted for in the Woodland Carbon Code's overall GHG mitigation potential.
Atmospheric Structure and Diurnal Variations at Low Altitudes in the Martian Tropics
NASA Astrophysics Data System (ADS)
Hinson, David P.; Spiga, A.; Lewis, S.; Tellmann, S.; Pätzold, M.; Asmar, S.; Häusler, B.
2013-10-01
We are using radio occultation measurements from Mars Express, Mars Reconnaissance Orbiter, and Mars Global Surveyor to characterize the diurnal cycle in the lowest scale height above the surface. We focus on northern spring and summer, using observations from 4 Martian years at local times of 4-5 and 15-17 h. We supplement the observations with results obtained from large-eddy simulations and through data assimilation by the UK spectral version of the LMD Mars Global Circulation Model. We previously investigated the depth of the daytime convective boundary layer (CBL) and its variations with surface elevation and surface properties. We are now examining unusual aspects of the temperature structure observed at night. Most important, predawn profiles in the Tharsis region contain an unexpected layer of neutral static stability at pressures of 200-300 Pa with a depth of 4-5 km. The mixed layer is bounded above by a midlevel temperature inversion and below by another strong inversion adjacent to the surface. The narrow temperature minimum at the base of the midlevel inversion suggests the presence of a water ice cloud layer, with the further implication that radiative cooling at cloud level can induce convective activity at lower altitudes. Conversely, nighttime profiles in Amazonis show no sign of a midlevel inversion or a detached mixed layer. These regional variations in the nighttime temperature structure appear to arise in part from large-scale variations in topography, which have several notable effects. First, the CBL is much deeper in the Tharsis region than in Amazonis, owing to a roughly 6-km difference in surface elevation. Second, large-eddy simulations show that daytime convection is not only deeper above Tharsis but also considerably more intense than it is in Amazonis. Finally, the daytime surface temperatures are comparable in the two regions, so that Tharsis acts as an elevated heat source throughout the CBL. These topographic effects are expected to enhance the vertical mixing of water vapor above elevated terrain, which might lead to the formation and regional confinement of nighttime clouds.
Temperature Inversions and Nighttime Convection in the Martian Tropics
NASA Astrophysics Data System (ADS)
Hinson, D. P.; Spiga, A.; Lewis, S.; Tellmann, S.; Paetzold, M.; Asmar, S. W.; Häusler, B.
2013-12-01
We are using radio occultation measurements from Mars Express, Mars Reconnaissance Orbiter, and Mars Global Surveyor to characterize the diurnal cycle in the lowest scale height above the surface. We focus on northern spring and summer, using observations from 4 Martian years at local times of 4-5 and 15-17 h. We supplement the observations with results obtained from large-eddy simulations and through data assimilation by the UK spectral version of the LMD Mars Global Circulation Model. We previously investigated the depth of the daytime convective boundary layer (CBL) and its variations with surface elevation and surface properties. We are now examining unusual aspects of the temperature structure observed at night. Most important, predawn profiles in the Tharsis region contain an unexpected layer of neutral static stability at pressures of 200-300 Pa with a depth of 4-5 km. The mixed layer is bounded above by a midlevel temperature inversion and below by another strong inversion adjacent to the surface. The sharp temperature minimum at the base of the midlevel inversion suggests the presence of a thin water ice cloud layer, with the further implication that radiative cooling at cloud level can induce convective activity at lower altitudes. Conversely, nighttime profiles in Amazonis show no sign of a midlevel inversion or a detached mixed layer. These regional variations in the nighttime temperature structure appear to arise in part from large-scale variations in topography, which have several notable effects. First, the CBL is much deeper in the Tharsis region than in Amazonis, owing to a roughly 6-km difference in surface elevation. Second, large-eddy simulations show that daytime convection is not only deeper above Tharsis but also considerably more intense than it is in Amazonis. Finally, the daytime surface temperatures are comparable in the two regions, so that Tharsis acts as an elevated heat source throughout the CBL. These topographic effects are expected to enhance the vertical mixing of water vapor above elevated terrain, which might lead to the formation and regional confinement of nighttime clouds.
Spaceborne GNSS reflectometry for ocean winds: First results from the UK TechDemoSat-1 mission
NASA Astrophysics Data System (ADS)
Foti, Giuseppe; Gommenginger, Christine; Jales, Philip; Unwin, Martin; Shaw, Andrew; Robertson, Colette; Roselló, Josep
2015-07-01
First results are presented for ocean surface wind speed retrieval from reflected GPS signals measured by the low Earth orbiting UK TechDemoSat-1 satellite (TDS-1). Launched in July 2014, TDS-1 provides the first new spaceborne Global Navigation Satellite System-Reflectometry (GNSS-R) data since the pioneering UK-Disaster Monitoring Mission (UK-DMC) experiment in 2003. Examples of onboard-processed delay-Doppler maps reveal excellent data quality for winds up to 27.9 m/s. Collocated Advanced Scatterometer (ASCAT) winds are used to develop and evaluate a wind speed algorithm based on signal-to-noise ratio (SNR) and the bistatic radar equation. For SNRs greater than 3 dB, wind speed is retrieved without bias and a precision around 2.2 m/s between 3 and 18 m/s even without calibration. Exploiting lower SNR signals, however, requires good knowledge of the antenna beam, platform attitude, and instrument gain setting. This study demonstrates the capabilities of low-cost, low-mass, and low-power GNSS-R receivers ahead of their launch on the NASA Cyclone GNSS (CYGNSS) constellation in 2016.
Decommissioning of magnox Ltd fuel cooling pond facilities in the UK
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bertoncini, Carlo
2013-07-01
Magnox reactors were the first generation of nuclear power stations built in the UK; ten sites in total, of which, nine had wet fuel routes with cooling ponds. Five ponds are currently in a decommissioning phase; this paper will focus primarily on Hunterston-A (HNA) Site and the central programme of work which governs its management. During its operation, the Cartridge Cooling Pond at HNA was used to receive the spent fuel discharged from the Site's two reactors, it was then stored for cooling purposes prior to dispatch off site. The current decommissioning phase focusses on draining the 6500 m{sup 3}more » pond. Due to the Site's limited caesium removal facilities, a stand-alone effluent treatment plant was constructed to improve abatement and reduce the pond activity from 200 to 0.7 Bq/ml (β). This was necessary due to increased environmental standards introduced since the site had ceased generation ten years previously. Early characterisation and experience from other sites concluded that if the pond were to be drained without any treatment to the walls, doses to the Operators, during subsequent decommissioning works, would routinely be in excess of 1 mSv.hr{sup -1}(γ). An opportunity was realised within the Ponds Programme that if the surface layer of the pond walls were to be removed during drain-down, ambient dose rates would be reduced by a factor of 10; this would allow for more cost-effective decommissioning options in the future. Ultrahigh pressure water jetting was tested and proved to yield a ∼95% total-activity reduction on treated surfaces. Challenges were overcome in providing safe and secure access to Decommissioning Operators to perform this operation by means of floating platforms on the surface of the pond. As strategies to clear facilities to exemption levels are becoming both cost prohibitive and not reasonably practicable, work is now underway in the Programme to determine the optimum condition for entry into long-term quiescent storage, prior to final demolition. This paper will discuss the strategy and techniques which led to Magnox Ltd ponds to be of national and international interest to the nuclear community. (authors)« less
NASA Astrophysics Data System (ADS)
van Grinsven, H. J. M.; ten Berge, H. F. M.; Dalgaard, T.; Fraters, B.; Durand, P.; Hart, A.; Hofman, G.; Jacobsen, B. H.; Lalor, S. T. J.; Lesschen, J. P.; Osterburg, B.; Richards, K. G.; Techen, A.-K.; Vertès, F.; Webb, J.; Willems, W. J.
2012-06-01
Implementation of the Nitrates Directive (NiD) and its environmental impacts were compared for member states in the Northwest of the European Union (Ireland, UK, Denmark, The Netherlands, Belgium, Northern France and Germany). The main sources of data were national reports for the third reporting period for the NiD (2004-2007) and results of the MITERRA-EUROPE model. Implementation of the NiD in the considered member states is fairly comparable regarding restrictions for where and when to apply fertilizer and manure, but very different regarding application limits for N fertilization. Issues of concern and improvement of the implementation of the NiD are accounting for the fertilizer value of nitrogen in manure, and relating application limits for total nitrogen (N) to potential crop yield and N removal. The most significant environmental effect of the implementation of the NiD since 1995 is a major contribution to the decrease of the soil N balance (N surplus), particularly in Belgium, Denmark, Ireland, The Netherlands and the UK. This decrease is accompanied by a modest decrease of nitrate concentrations since 2000 in fresh surface waters in most countries. This decrease is less prominent for groundwater in view of delayed response of nitrate in deep aquifers. In spite of improved fertilization practices, the southeast of The Netherlands, the Flemish Region and Brittany remain to be regions of major concern in view of a combination of a high nitrogen surplus, high leaching fractions to groundwater and tenacious exceedance of the water quality standards. On average the gross N balance in 2008 for the seven member states in EUROSTAT and in national reports was about 20 kg N ha-1 lower than by MITERRA. The major cause is higher estimates of N removal in national reports which can amount to more than 50kg N ha-1. Differences between procedures in member states to assess nitrogen balances and water quality and a lack of cross boundary policy evaluations are handicaps when benchmarking the effectiveness of the NiD. This provides a challenge for the European Commission and its member states as the NiD remains an important piece of legislation for protecting drinking water quality in regions with many private or small public production facilities and controlling aquatic eutrophication from agricultural sources.
Musk, Will; Faulwetter, Sarah; McIlwaine, Paul
2016-01-01
During a benthic survey of a Marine Conservation Zone located on the Skerries Bank in the English Channel off the south-west coast of England, three specimens of Streptosyllis nunezi Faulwetter et al., 2008 were found. This is the second ever record of the species after its original description, and the first record from waters around the U.K. and a significant northerly range extension for a species previously only recorded from the Canary Islands and the Mediterranean Sea. A single simple ventral chaeta in each of the two posterior-most segments was discovered in this and two other species of Streptosyllis Webster & Benedict, 1884. The generic definition of Streptosyllis is emended to include this feature previously unknown for the genus, and an updated key to the Streptosyllis found in UK waters is provided.
How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?
Zięba, Grzegorz; Fox, Michael G; Copp, Gordon H
2015-01-01
Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts) appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime.
Atmospheric CO2 sequestration in iron and steel slag: Consett, Co. Durham, UK.
Mayes, William Matthew; Riley, Alex L; Gomes, Helena I; Brabham, Peter; Hamlyn, Joanna; Pullin, Huw; Renforth, Phil
2018-06-12
Carbonate formation in waste from the steel industry could constitute a non-trivial proportion of global requirements to remove carbon dioxide from the atmosphere at potentially low cost. To constrain this potential, we examined atmospheric carbon dioxide sequestration in a >20 million tonne legacy slag deposit in northern England, UK. Carbonates formed from the drainage water of the heap had stable carbon and oxygen isotopes between -12 and -25 ‰ and -5 and -18 ‰ for δ13C and δ18O respectively, suggesting atmospheric carbon dioxide sequestration in high pH solutions. From analysis of solution saturation state, we estimate that between 280 and 2,900 tCO2 have precipitated from the drainage waters. However, by combining a thirty-seven-year dataset of the drainage water chemistry with geospatial analysis, we estimate that <1 % of the maximum carbon capture potential of the deposit may have been realised. This implies that uncontrolled deposition of slag is insufficient to maximise carbon sequestration, and there may be considerable quantities of unreacted legacy deposits available for atmospheric carbon sequestration.
NASA Astrophysics Data System (ADS)
Short, Chrisopher; Clarke, Lucy; Uttley, Chris; Smith, Brian
2017-04-01
Following severe flooding in 2007, and subsequent smaller flood events, a decision was taken in 2012 to explore nature-based solutions in 250km2 river catchment in the southern Cotswolds in the UK. A major tributary within the catchment has been designated as rapid response; with a primarily limestone geology limestone and a mixture of spring and surface drained sources along a number of tributaries feeding in the river, with one main population centre where the water bodies converge. The project involves landscape and land management interventions aimed at attenuating high flows to reduce flood risk through changes in land management practices in both agriculture and forestry and slowing peak flows in surface flows through increased infiltration and attenuation areas. After three years of the project it is clear that the threshold for effectiveness requires the majority of the upstream catchment area to be implementing these measures. However, the cost effectiveness of the approach seems to be substantial compared to traditional hard-engineering approaches. The level of community involvement, including local flood forums, is high and the social, and natural, capital has been enhanced through the project. Early results suggest that there have been localized improvements in water quality and biodiversity as well as a reduction in peak flow but such changes are difficult to directly associate to the project. What is clear is the role of communities, landowners and partners to implement natural flood management on a catchment wide scale. In this sense the project has adopted a co-management or adaptive management approach which brings together the knowledges of hydrologists, ecologists, farmers, woodland owners and the local community to implement locally be-spoke solutions within a broader project framework. This paper will outline the initial findings and the governance structure that has assisted in the early success of the project within a theoretical framework of co-management and suggest how this type of framework is suitable for a range of nature-based solutions across Europe. However, the challenge remains of capturing the multiple-benefits that such projects offer as these are often missed through conventional approaches such as cost-benefit analysis and some reflections on this will also be presented along with a potential way forward.
Beyond 'flood hotspots': Modelling emergency service accessibility during flooding in York, UK
NASA Astrophysics Data System (ADS)
Coles, Daniel; Yu, Dapeng; Wilby, Robert L.; Green, Daniel; Herring, Zara
2017-03-01
This paper describes the development of a method that couples flood modelling with network analysis to evaluate the accessibility of city districts by emergency responders during flood events. We integrate numerical modelling of flood inundation with geographical analysis of service areas for the Ambulance Service and the Fire & Rescue Service. The method was demonstrated for two flood events in the City of York, UK to assess the vulnerability of care homes and sheltered accommodation. We determine the feasibility of emergency services gaining access within the statutory 8- and 10-min targets for high-priority, life-threatening incidents 75% of the time, during flood episodes. A hydrodynamic flood inundation model (FloodMap) simulates the 2014 pluvial and 2015 fluvial flood events. Predicted floods (with depth >25 cm and areas >100 m2) were overlain on the road network to identify sites with potentially restricted access. Accessibility of the city to emergency responders during flooding was quantified and mapped using; (i) spatial coverage from individual emergency nodes within the legislated timeframes, and; (ii) response times from individual emergency service nodes to vulnerable care homes and sheltered accommodation under flood and non-flood conditions. Results show that, during the 2015 fluvial flood, the area covered by two of the three Fire & Rescue Service stations reduced by 14% and 39% respectively, while the remaining station needed to increase its coverage by 39%. This amounts to an overall reduction of 6% and 20% for modelled and observed floods respectively. During the 2014 surface water flood, 7 out of 22 care homes (32%) and 15 out of 43 sheltered accommodation nodes (35%) had modelled response times above the 8-min threshold from any Ambulance station. Overall, modelled surface water flooding has a larger spatial footprint than fluvial flood events. Hence, accessibility of emergency services may be impacted differently depending on flood mechanism. Moreover, we expect emergency services to face greater challenges under a changing climate with a growing, more vulnerable population. The methodology developed in this study could be applied to other cities, as well as for scenario-based evaluation of emergency preparedness to support strategic decision making, and in real-time forecasting to guide operational decisions where heavy rainfall lead-time and spatial resolution are sufficient.
Understanding drought propagation in the UK in the context of climatology and catchment properties
NASA Astrophysics Data System (ADS)
Barker, Lucy; Hannaford, Jamie; Bloomfield, John; Marchant, Ben
2017-04-01
Droughts are a complex natural phenomena that are challenging to plan and prepare for. The propagation of droughts through the hydrological cycle is one of many factors which contribute to this complexity, and a thorough understanding of drought propagation is crucial for informed drought management, particularly in terms of water resources management in both the short and long term. Previous studies have found that both climatological and catchment factors cause lags in drought propagation from meteorological to hydrological and hydrogeological droughts. There are strong gradients in both climatology and catchment properties across the UK. Catchments in the north and west of the UK are relatively impermeable, upland catchments with thin soils and receive the highest annual precipitation with relatively low mean annual temperatures. Conversely, in the south and east of the UK, characterised by higher mean temperatures and lower annual precipitation, catchments are underlain by a number of major aquifers (e.g. Chalk, limestone) and are typically associated with high baseflow rivers. Here we explore the effects of these gradients in climatology and catchments on the propagation of droughts. Using standardised drought indices (the Standardised Precipitation Index; the Standardised Streamflow Index; and the Standardised Groundwater Index) we analyse drought propagation characteristics for selected catchment-borehole pairs across the UK using reconstructed time series back to the 19th century. We investigate how the timing, nature and predictability of drought propagation changes across the UK, given gradients in climatology and catchment characteristics. We use probability of detection methods, usually used for forecast verification, to investigate how well precipitation and streamflow deficits predict deficits in streamflow and groundwater levels and how this varies across the UK.
NASA Astrophysics Data System (ADS)
Fu, Lee-Lueng; Morrow, Rosemary
2016-07-01
The global observations of the sea surface height (SSH) have revolutionized oceanography since the beginning of precision radar altimetry in the early 1990s. For the first time we have continuous records of SSH with spatial and temporal sampling for detecting the global mean sea level rise, the waxing and waning of El Niño, and the ocean circulation from gyres to ocean eddies. The limit of spatial resolution of the present constellation of radar altimeters in mapping SSH variability is approaching 100 km (in wavelength) with 3 or more simultaneous altimetric satellites in orbit. At scales shorter than 100 km, the circulation contains substantial amount of kinetic energy in currents, eddies and fronts that are responsible for the stirring and mixing of the ocean, especially from the vertical exchange of the upper ocean with the deep. A mission currently in development will use the technique of radar interferometry for making high-resolution measurement of the height of water over the ocean as well as on land. It is called Surface Water and Ocean Topography (SWOT), which is a joint mission of US NASA and French CNES, with contributions from Canada and UK. SWOT promises the detection of SSH at scales approaching 15 km, depending on the sea state. SWOT will make SSH measurement over a swath of 120 km with a nadir gap of 20 km in a 21-day repeat orbit. A conventional radar altimeter will provide measurement along the nadir. This is an exploratory mission with applications in oceanography and hydrology. The increased spatial resolution offers an opportunity to study ocean surface processes to address important questions about the ocean circulation. However, the limited temporal sampling poses challenges to map the evolution of the ocean variability that changes rapidly at the small scales. The measurement technique and the development of the mission will be presented with emphasis on its science program with outlook on the opportunities and challenges.
The effects of elevated CO2 and eutrophication on surface elevation gain in a European salt marsh.
Reef, Ruth; Spencer, Tom; Mӧller, Iris; Lovelock, Catherine E; Christie, Elizabeth K; McIvor, Anna L; Evans, Ben R; Tempest, James A
2017-02-01
Salt marshes can play a vital role in mitigating the effects of global environmental change by dissipating incident storm wave energy and, through accretion, tracking increasing water depths consequent upon sea level rise. Atmospheric CO 2 concentrations and nutrient availability are two key variables that can affect the biological processes that contribute to marsh surface elevation gain. We measured the effects of CO 2 concentrations and nutrient availability on surface elevation change in intact mixed-species blocks of UK salt marsh using six open-top chambers receiving CO 2 -enriched (800 ppm) or ambient (400 ppm) air. We found more rapid surface elevation gain in elevated CO 2 conditions: an average increase of 3.4 mm over the growing season relative to ambient CO 2 . Boosted regression analysis to determine the relative influence of different parameters on elevation change identified that a 10% reduction in microbial activity in elevated CO 2 -grown blocks had a positive influence on elevation. The biomass of Puccinellia maritima also had a positive influence on elevation, while other salt marsh species (e.g. Suaeda maritima) had no influence or a negative impact on elevation. Reduced rates of water use by the vegetation in the high CO 2 treatment could be contributing to elevation gain, either directly through reduced soil shrinkage or indirectly by decreasing microbial respiration rates due to lower redox levels in the soil. Eutrophication did not influence elevation change in either CO 2 treatment despite doubling aboveground biomass. The role of belowground processes (transpiration, root growth and decomposition) in the vertical adjustment of European salt marshes, which are primarily minerogenic in composition, could increase as atmospheric CO 2 concentrations rise and should be considered in future wetland models for the region. Elevated CO 2 conditions could enhance resilience in vulnerable systems such as those with low mineral sediment supply or where migration upwards within the tidal frame is constrained. © 2016 John Wiley & Sons Ltd.
Environmental baselines: preparing for shale gas in the UK
NASA Astrophysics Data System (ADS)
Bloomfield, John; Manamsa, Katya; Bell, Rachel; Darling, George; Dochartaigh, Brighid O.; Stuart, Marianne; Ward, Rob
2014-05-01
Groundwater is a vital source of freshwater in the UK. It provides almost 30% of public water supply on average, but locally, for example in south-east England, it is constitutes nearly 90% of public supply. In addition to public supply, groundwater has a number of other uses including agriculture, industry, and food and drink production. It is also vital for maintaining river flows especially during dry periods and so is essential for maintaining ecosystem health. Recently, there have been concerns expressed about the potential impacts of shale gas development on groundwater. The UK has abundant shales and clays which are currently the focus of considerable interest and there is active research into their characterisation, resource evaluation and exploitation risks. The British Geological Survey (BGS) is undertaking research to provide information to address some of the environmental concerns related to the potential impacts of shale gas development on groundwater resources and quality. The aim of much of this initial work is to establish environmental baselines, such as a baseline survey of methane occurrence in groundwater (National methane baseline study) and the spatial relationships between potential sources and groundwater receptors (iHydrogeology project), prior to any shale gas exploration and development. The poster describes these two baseline studies and presents preliminary findings. BGS are currently undertaking a national survey of baseline methane concentrations in groundwater across the UK. This work will enable any potential future changes in methane in groundwater associated with shale gas development to be assessed. Measurements of methane in potable water from the Cretaceous, Jurassic and Triassic carbonate and sandstone aquifers are variable and reveal methane concentrations of up to 500 micrograms per litre, but the mean value is relatively low at < 10 micrograms per litre. These values compare with much higher levels of methane in aquicludes and thermal waters, for example from the Carboniferous and Triassic which have concentrations in excess of 1500 micrograms per litre. It is important to understand the spatial relationships between potential shale gas source rocks and overlying aquifers if shale gas is to be developed in a safe and sustainable manner. The BGS and the Environment Agency have undertaken a national-scale study of the UK to assess the vertical separation between potential shale gas source rocks and major aquifers (iHydrogeology project). Aquifer - shale separations have been documented in the range <200m to >2km. The geological modelling process will be presented and discussed along with maps combining the results of the methane baseline study, the distribution of Principal Aquifers and shale/clay units, and aquifer - shale separation maps for the UK.
Restoration of shallow peatlands on Exmoor (UK): initial effects on water quality
NASA Astrophysics Data System (ADS)
Grand-Clement, Emilie; Luscombe, David; Anderson, Karen; Gatis, Naomi; Ashe, Josie; Brazier, Richard
2014-05-01
Historical and recent anthropogenic pressure has had dramatic effects on peatlands throughout the UK. In the South West, drainage for agricultural reclamation and peat cutting since the 19th century has progressively altered the hydrological behaviour of the peatlands of Exmoor and Dartmoor National Parks. Lower water table levels have caused increased oxidation, erosion and vegetation change, further affecting the storage of carbon and the provision of other ecosystem services (i.e. supply of drinking water, biodiversity). Moreover, the location of these peatlands at the southernmost margin of the UK peatlands' geographical extent makes them extremely vulnerable to the predicted effects of climate change, i.e. increased temperature and change in rainfall pattern. An extensive programme of peatland restoration is currently underway on Exmoor. Drainage ditches were blocked to reinstate the hydrological behaviour, reduce the outflow of dissolved organic carbon and, in doing so, improve other ecosystem services delivered by peatlands. This paper will report on the water quality monitoring results from a small headwater catchment in Exmoor. We will show results comparing changes in Dissolved Organic Carbon (DOC) losses and colour pre- and post-restoration. Our experimental approach uses event-based water quality monitoring across three drainage ditches that are representative of the different scales of damage in the area. Samples were taken back to the laboratory and analysed for DOC and colour, using UV spectrophotometry and UV-vis spectrometry respectively. DOC loads were calculated using discharge for each drain. Overall, DOC concentrations ranged between 3 and 30mg/L. Both pre and post- restoration datasets presented high seasonal variability, with higher concentrations measured from June to September. No significant change in DOC concentrations was observed in the 6 months after restoration. It is hypothesised that the effects of restoration could be hidden by inter-annual variations in total and mean rainfall over the period monitored. However, significant changes in water quantity, such as a reduction in storm flow following restoration, means that, overall, DOC loads have decreased at the scale of the catchment. These results show the need for an integrated approach in catchment management, considering all trade-offs between ecosystem services before assessing the effects of restoration.
A relationship between dissolved CO2 and the non-volatile chemistry of rainwater.
NASA Astrophysics Data System (ADS)
Durham, Brian; Pfrang, Christian
2016-04-01
Measurements of a volatile acid component in UK rainwater in 2009 implicated CO2, and speculated `a concentrating mechanism (that) could mean that this weakly soluble molecule is recycled at a faster rate than inferred by its Henry's Law constant'. Last year's EGU Presentation 2015-3386 confirmed that the `saturated CO2 content (of UK rainwater) is insignificant, the bulk transport being the volatile component'. However the atmospheric capture mechanism remains enigmatic. For pure water, improved temperature control has discounted the predicted upturn in the Henry coefficient for 450Pa CO2 as the temperature approached freezing point (http://presentations.copernicus.org/EGU2015-3386_presentation.pptx), and the focus has therefore turned to rainwater chemistry. For a mid-range sample the Henry value was: • significantly higher than pure water at 20'C; • but decreasing with lower temperatures. The higher Henry constant might suggest that, as an acid anhydride, CO2 is subject to selective capture where cloud water is alkaline (terrestrial dust or marine aerosol). Analysis has however shown no simple relationship between [CO2]aq and either acidity or conductivity of the carrier water. Seeking therefore a coherent distribution, stripped CO2 was plotted against Δ[H+], from which this paper presents a tight wedge-shaped distribution of 263 UK rain/snow events. The inference is that [CO2]aq is not related directly to [H+], but possibly to Group 1 and 2 cations from marine aerosol that are buffering the cloud water acidity. By contrast, the unexpected decrease in CO2 yield with lower temperatures proved to be an artefact of a progressively slower rate of de-gassing, cooler samples still equilibrating after 100 minutes. An ultrasound stripper is therefore being developed to speed the Henry measurements, and for reproducibility it is proposed to dilute a proprietary `standard Atlantic sea water' to a representative range of conductivities, to be called `standard rainwater'. Any temptation to extrapolate from English results to address the global boundary layer is resisted pending ΔpH values from other stations, which are herewith invited in anticipation of IPCC AR6.
NASA Astrophysics Data System (ADS)
Sykes, Helena; Neale, Simon; Coe, Sarah
2016-04-01
Natural Resources Wales is a UK government body responsible for environmental regulation, among other areas. River walks in Water Framework Directive (WFD) priority catchments in South West Wales, UK, identified soil entering water courses due to poaching and bank erosion, leading to deterioration in the water quality and jeopardising the water quality meeting legal minimum standards. Bare soil has also been shown to cause quicker and higher hydrograph peaks in rural catchments than if those areas were vegetated, which can lead to flooding of domestic properties during peak storm flows. The aim was to target farm visits by operational staff to advise on practices likely to improve water quality and to identify areas where soft engineering solutions such as revegetation could alleviate flood risk in rural areas. High resolution colour-infrared aerial photography, 25cm in the three colour bands and 50cm in the near infrared band, was used to map bare soil in seven catchments using supervised classification of a five band stack including the Normalised Difference Vegetation Index (NDVI). Mapping was combined with agricultural land use and field boundary data to filter out arable fields, which are supposed to bare soil for part of their cycle, and was very successful when compared to ground truthing, with the exception of silage fields which contained sparse, no or unproductive vegetation at the time the imagery was acquired leading to spectral similarity to bare soil. A raindrop trace model was used to show the path sediment from bare soil areas would take when moving through the catchment to a watercourse, with hedgerows inserted as barriers following our observations from ground truthing. The findings have been used to help farmers gain funding for improvements such as fencing to keep animals away from vulnerable river banks. These efficient and automated methods can be rolled out to more catchments in Wales and updated using aerial imagery acquired more recently to examine the effects of change.
How Well do we Measure Precipitation? 'Wind-Induced Undercatch' Revisited
NASA Astrophysics Data System (ADS)
Pollock, M.; Colli, M.; Dutton, M.; O'Donnell, G. M.; Wilkinson, M.; Black, A.; Kilsby, C. G.; Quinn, P. F.; Lanza, L. G.; Stagnaro, M.; O'Connell, P. E.
2016-12-01
Data from precipitation gauges are critical for flood forecasting and flood risk management; radar calibration and numerical weather prediction models; and water resource management and hydrological modelling. They are often considered to provide the most accurate practicable measure of precipitation at a point in space and time, but remain subject to considerable errors. Inaccuracies in measurements are compounded in modelling applications by producing potentially misleading or incorrect results; it is therefore of utmost importance to understand uncertainty in observations. All precipitation gauges mounted above the ground surface present an obstruction to the prevailing wind. This causes an acceleration of wind above the orifice of a gauge resulting in what is commonly referred to as `wind-induced undercatch'. This is where precipitation is deflected away from the orifice and lands 'downstream' of the area represented by the gauge measurement, which reduces its collection efficiency (CE). The physical shape of a gauge bears a significant impact on its CE. Computational Fluid Dynamic (CFD) simulations are used to investigate how different shapes of precipitation gauge are affected by the wind. The CFD modelling is supported by high-resolution field measurements at several exposed `Hydro-Met' research stations in the UK. These sites are occupied by a range of precipitation gauges, scrutinised in the CFD analysis, which have different shapes and are mounted at varying heights. The wind-induced undercatch present within a number of large UK storms, which is not captured by operational gauge networks in the UK, is quantified and presented in this study. The combination of results from CFD modelling and the field studies show that gauge shape and mounting height significantly affect the extent of the `undercatching'. `Aerodynamic' gauges following a `champagne flute' or a `funnel' profile were demonstrated by both to have significant advantages over conventional gauge shapes, in terms of improving the CE.
Orbitally-resolved SST Changes during the EOT: Results from IODP 342 Expedition
NASA Astrophysics Data System (ADS)
Liu, Z.; He, Y.; Wilson, P. A.; Pagani, M.
2014-12-01
Sea surface temperature (SST) changes during the Eocene-Oligocene climate transition were characterized by substantial cooling at high latitudes and less cooling in low latitudes, with little information from mid-latitudes so far. Taking advantage of the newly retrieved drift sediments from the IODP 342 Expedition, we aim to reconstruct SST changes at the mid-latitude Newfoundland region, at an unprecedented orbital resolution from Site U1411. During the period investigated, 32-36 Ma, the alkenone UK'37 values range from 0.65 to 0.95, with values all greater than 0.80 before the transition and lower values (<0.80) occurring approximately at the eccentricity minimum nodes after the transition. No immediate cooling associated with Oi-1 glaciation was observed. During the Oligocene, SSTs during warm epochs (corresponding to eccentricity maxima) were not significantly cooler than before. Overall, SST fluctuations appear to be modulated by orbital changes throughout the record, although more apparent due to larger amplitude of SST variability after the transition. We thus hypothesize that the mid-latitude Newfoundland region was largely bathed by low-latitude warm waters during the transition and that polar waters (fronts) reached to the region occasionally at periods of eccentricity minimum nodes during the Oligocene.
The potential impact of ozone on materials in the U.K.
NASA Astrophysics Data System (ADS)
Lee, David S.; Holland, Michael R.; Falla, Norman
Recent reports have highlighted the potential damage caused to a range of media, including materials, by ozone (O 3). The limited data available indicate significant damage to rubber products and surface coatings but either insignificant or unquantifiable damage to textiles and other polymeric materials at the range of atmospheric concentrations encountered in the U.K. Materials in the indoor environment have been excluded from economic analyses. Legislation was put in place in 1993 in the U.K. in order to reduce NO x (NO x = NO + NO 2) and VOC (volatile organic compounds) emissions from motor vehicles which is likely to result in reduced peak O 3 episodes but increased average levels of O 3 in urban areas which may result in increased damage to materials. A detailed assessment of the costs of O 3 damage to materials is not currently possible because of insufficient information on relevant dose-response functions and the stock at risk. Alternative methods were thus adopted to determine the potential scale of the problem. Scaling of U.S. estimates made in the late 1960s provides a range for the U.K. of £170 million-£345 million yr -1 in current terms. This includes damage to surface coatings and elastomers, and the cost of antiozonant protection applied to rubber goods. Independent estimates were made of the costs of protecting rubber goods in the U.K. These were based on the size of the antiozonant market, and provide cost ranges of £25 million-£63 million yr -1 to manufacturers and £25 million-£189 million yr -1 to consumers. The only rubber goods for which a damage estimate (not including protection costs) could be made were tyres, using data from the U.S.A. and information on annual tyre sales in the U.K. A range of £0-£4 million yr -1 was estimated. The cost of damage to other rubber goods could not be quantified because of a lack of data on both the stock at risk and exposure-response functions. The effect of O 3 on the costs of repainting were estimated under scenarios of increased urban concentrations of O 3 using damage functions derived from the literature. The cost was estimated to be in the range of £0-£60 million yr -1 for a change from 15 to 20 ppb O 3, and £0 to £182 million yr -1 for a change from 15 to 30 ppb O 3. The wide ranges derived for effects on surface coatings are a reflection of the uncertainty associated with the dose-response functions used.
Mortality from disease among fishermen employed in the UK fishing industry from 1948 to 2005.
Roberts, Stephen E; Rodgers, Sarah E; Williams, Judy C
2007-01-01
Although commercial fishing has become established as the most hazardous occupation in Western countries, relatively little has been reported on mortality from disease among fishermen. To investigate the causes of work-related mortality from disease in the UK fishing industry from 1948 to 2005, trends in mortality over time and how it varies according to the sector of the fishing industry, to investigate non-work related mortality among fishermen ashore, and to compare it with that in other populations. Examination of paper death inquiry files, death registers and death returns, as well as GIS mapping for a defined population of 1.45 million fishermen-years at risk. From 1948 to 2005, there were a total of 449 work-related deaths from disease identified in the UK fishing industry, with a corresponding mortality rate of 30.9 per 100,000. The mortality rate increased from about 35 per 100,000 in the late 1940s to 60 in the early/mid 1970s but fell sharply to about 10 by the late 1970s. Most of the deaths were caused by ischaemic heart disease followed by other circulatory diseases, respiratory and gastrointestinal diseases. The highest mortality rates were identified for fishermen employed on board distant water trawlers, particularly those operating in Arctic waters. The study shows that fishermen in distant water trawlers, particularly in Arctic conditions, have the highest risks of mortality from disease. The high risks presumably reflect lifestyle risk factors as well as extremely hazardous and stressful working and sleeping conditions.
A novel representation of chalk hydrology in a land surface model
NASA Astrophysics Data System (ADS)
Rahman, Mostaquimur; Rosolem, Rafael
2016-04-01
Unconfined chalk aquifers contain a significant portion of water in the United Kingdom. In order to optimize the assessment and management practices of water resources in the region, modelling and monitoring of soil moisture in the unsaturated zone of the chalk aquifers are of utmost importance. However, efficient simulation of soil moisture in such aquifers is difficult mainly due to the fractured nature of chalk, which creates high-velocity preferential flow paths in the unsaturated zone. In this study, the Joint UK Land Environment Simulator (JULES) is applied on a study area encompassing the Kennet catchment in Southern England. The fluxes and states of the coupled water and energy cycles are simulated for 10 consecutive years (2001-2010). We hypothesize that explicit representation for the soil-chalk layers and the inclusion of preferential flow in the fractured chalk aquifers improves the reproduction of the hydrological processes in JULES. In order to test this hypothesis, we propose a new parametrization for preferential flow in JULES. This parametrization explicitly describes the flow of water in soil matrices and preferential flow paths using a simplified approach which can be beneficial for large-scale hydrometeorological applications. We also define the overlaying soil properties obtained from the Harmonized World Soil Database (HWSD) in the model. Our simulation results are compared across spatial scales with measured soil moisture and river discharge, indicating the importance of accounting for the physical properties of the medium while simulating hydrological processes in the chalk aquifers.
Byrne, Patrick; Reid, Ian; Wood, Paul J
2013-03-01
Contaminated drainage from metal mines is a serious water-quality problem facing nations that exploit metal mineral resources. Measurements of river hydrochemistry during baseflow are common at mine sites, whilst detailed hydrochemical information regarding stormflow is limited and often confined to a single event. This study investigates the seasonal evolution of stormflow hydrochemistry at an abandoned metal mine in central Wales, UK, and the possible sources and mechanisms of metal release. Significant flushing of metals was observed during stormflow events, resulting in concentrations that severely exceeded water-quality guidelines. The relationship between metal concentrations and river discharge suggests dissolution of efflorescent metal sulphates on the surface of the mine spoil as the principal source of the contamination. High fluxes of Pb during stormflows are linked to extended periods of dry weather prior to storm events that produced water table drawdown and encouraged oxidation of Pb sulphide in the mine spoil. However, some Pb flushing also occurred following wet antecedent conditions. It is suggested that Fe oxide reduction in mine spoil and translatory flows involving metal-rich pore waters results in flushing during wetter periods. Detailed measurements of stormflow hydrochemistry at mine sites are essential for accurate forecasting of long-term trends in metals flux to understand metal sources and mechanisms of release, to assess potential risks to water quality and instream ecology, and to gauge the potential effectiveness of remediation. In order to protect riverine and riparian ecosystems, it is suggested that routine monitoring of stormflows becomes part of catchment management in mining-impacted regions.
NASA Astrophysics Data System (ADS)
Parry, Simon; Barker, Lucy; Hannaford, Jamie; Prudhomme, Christel; Smith, Katie; Svensson, Cecilia; Tanguy, Maliko
2017-04-01
Hydrological droughts of the last 50 years in the UK have been well characterised owing to a relatively dense hydrometric network. Prior to this, observed river flow data were generally limited in their spatial coverage and often subject to considerable uncertainty. Whilst qualitative records indicate the occurrence of severe droughts in the late 19th and early 20th centuries, including scenarios which may cause substantial impacts to contemporary water supply systems, existing observations are not sufficient to describe their spatio-temporal characteristics. As such, insights on drought in the UK are constrained and a range of stakeholders including water companies and regulators would benefit from a more thorough assessment of historic drought characteristics and their variability. The multi-disciplinary Historic Droughts project aims to rigorously characterise droughts in the UK to inform improved drought management and communication. Driven by rainfall and potential evapotranspiration data that have been extended using recovered records, lumped catchment hydrological models are used to reconstruct daily river flows from 1890 to 2015 for more than 200 catchments across the UK. The reconstructions are derived within a state-of-the-art modelling framework which allows a comprehensive assessment of model, structure and parameter uncertainty. Standardised and threshold-based indicators are applied to the river flow reconstructions to identify and characterise hydrological drought events. The reconstructions are most beneficial in comprehensively describing well known but poorly quantified late 19th and early 20th century droughts, placing the spatial and temporal footprint of these often extreme events within the context of modern episodes for the first time. Oscillations between drought-rich and drought-poor periods are shown not to be limited to the recent observational past, providing an increased sample size of events against which to test a range of airflow and oceanic index patterns as potential drivers of streamflow drought. The quantification of changes over time in both the mean and the variability of drought frequency, duration, severity and termination benefits from the temporal extent of the river flow reconstructions, assessing the temporal variability of drought over more prolonged timescales than previous drought trend studies. When considered alongside complimentary reconstructions of rainfall and groundwater levels, the characteristics of propagation from meteorological to hydrological drought are analysed to an extent not previously possible. The unprecedented spatio-temporal coverage of the river flow reconstructions has yielded important new insights on historic droughts in the UK. It is hoped that this more robust assessment of the historical variability of hydrological drought in the UK will underpin enhanced drought planning and management.
Ojeil, M; Jermann, C; Holah, J; Denyer, S P; Maillard, J-Y
2013-12-01
Antimicrobial surfaces aim to reduce microbial bioburden and improve hygiene. The current antimicrobial surface efficacy test (ISO22196) is an initial screening test but its conditions, high temperature (37°C) and relative humidity (RH) (100%) bear little relationship to in-use conditions. To develop an antimicrobial surface efficacy test providing a realistic second-tier test, simulating in-use conditions. Surface relative humidity, temperature and soiling were measured over one year at a UK hospital, enabling realistic parameters to be set for our surface efficacy test. A nebulizer, connected to a cascade impactor, aerosolized and uniformly deposited a Staphylococcus aureus suspension over test copper alloys and control stainless steel surfaces. Bacteria were enumerated following nebulization, and after a range of contact times, under [20°C, 50% RH] and [20°C, 40% RH] parameters reflecting in-use conditions; [37°C, 100% RH] was employed to reflect conditions used in ISO22196. All copper alloys produced a >4 log10 reduction after 24h under all conditions tested. Copper alloys were more effective at [37°C, 100% RH] showing a >4 log10 reduction after 30 min than at in-use conditions [20°C, 50% RH and 20°C, 40% RH], for which 60 min was required to achieve the same level of kill, for most but not all alloys. The use of the nebulizer to deposit bacterial inocula on surfaces showed little variability in results. Our method was more discriminatory than the ISO22196 enabling distinction between the bactericidal surface activity, which allows for a more rigorous selection of antimicrobial surfaces for potential use in healthcare settings. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
Wang, L; Butcher, A S; Stuart, M E; Gooddy, D C; Bloomfield, J P
2013-10-01
Nitrate pollution in groundwater, which is mainly from agricultural activities, remains an international problem. It threatens the environment, economics and human health. There is a rising trend in nitrate concentrations in many UK groundwater bodies. Research has shown it can take decades for leached nitrate from the soil to discharge into groundwater and surface water due to the 'store' of nitrate and its potentially long travel time in the unsaturated and saturated zones. However, this time lag is rarely considered in current water nitrate management and policy development. The aim of this study was to develop a catchment-scale integrated numerical method to investigate the nitrate lag time in the groundwater system, and the Eden Valley, UK, was selected as a case study area. The method involves three models, namely the nitrate time bomb-a process-based model to simulate the nitrate transport in the unsaturated zone (USZ), GISGroundwater--a GISGroundwater flow model, and N-FM--a model to simulate the nitrate transport in the saturated zone. This study answers the scientific questions of when the nitrate currently in the groundwater was loaded into the unsaturated zones and eventually reached the water table; is the rising groundwater nitrate concentration in the study area caused by historic nitrate load; what caused the uneven distribution of groundwater nitrate concentration in the study area; and whether the historic peak nitrate loading has reached the water table in the area. The groundwater nitrate in the area was mainly from the 1980s to 2000s, whilst the groundwater nitrate in most of the source protection zones leached into the system during 1940s-1970s; the large and spatially variable thickness of the USZ is one of the major reasons for unevenly distributed groundwater nitrate concentrations in the study area; the peak nitrate loading around 1983 has affected most of the study area. For areas around the Bowscar, Beacon Edge, Low Plains, Nord Vue, Dale Springs, Gamblesby, Bankwood Springs, and Cliburn, the peak nitrate loading will arrive at the water table in the next 34 years; statistical analysis shows that 8.7 % of the Penrith Sandstone and 7.3 % of the St Bees Sandstone have not been affected by peak nitrate. This research can improve the scientific understanding of nitrate processes in the groundwater system and support the effective management of groundwater nitrate pollution for the study area. With a limited number of parameters, the method and models developed in this study are readily transferable to other areas.
The Mars Analysis Correction Data Assimilation (MACDA): A reference atmospheric reanalysis
NASA Astrophysics Data System (ADS)
Montabone, Luca; Read, Peter; Lewis, Stephen; Steele, Liam; Holmes, James; Valeanu, Alexandru
2016-07-01
The Mars Analysis Correction Data Assimilation (MACDA) dataset version 1.0 contains the reanalysis of fundamental atmospheric and surface variables for the planet Mars covering a period of about three Martian years (late MY 24 to early MY 27). This has been produced by data assimilation of retrieved thermal profiles and column dust optical depths from NASA's Mars Global Surveyor/Thermal Emission Spectrometer (MGS/TES), which have been assimilated into a Mars global climate model (MGCM) using the Analysis Correction scheme developed at the UK Meteorological Office. The MACDA v1.0 reanalysis is publicly available, and the NetCDF files can be downloaded from the archive at the Centre for Environmental Data Analysis/British Atmospheric Data Centre (CEDA/BADC). The variables included in the dataset can be visualised using an ad-hoc graphical user interface (the "MACDA Plotter") at the following URL: http://macdap.physics.ox.ac.uk/ MACDA is an ongoing collaborative project, and work is currently undertaken to produce version 2.0 of the Mars atmospheric reanalysis. One of the key improvements is the extension of the reanalysis period to nine martian years (MY 24 through MY 32), with the assimilation of NASA's Mars Reconnaissance Orbiter/Mars Climate Sounder (MRO/MCS) retrievals of thermal and dust opacity profiles. MACDA 2.0 is also going to be based on an improved version of the underlying MGCM and an updated scheme to fully assimilate (radiative active) tracers, such as dust and water ice.
NASA Astrophysics Data System (ADS)
González Benítez, Juan M.; Cape, J. Neil; Heal, Mathew R.; van Dijk, Netty; Díez, Alberto Vidal
Water soluble organic nitrogen (WSON) compounds are ubiquitous in precipitation and in the planetary boundary layer, and therefore are a potential source of bioavailable reactive nitrogen. This paper examines weekly rain data over a period of 22 months from June 2005 to March 2007 collected in 2 types of rain collector (bulk deposition and "dry + wet" deposition) located in a semi-rural area 15 km southwest of Edinburgh, UK (N55°51'44″, W3°12'19″). Bulk deposition collectors are denoted in this paper as "standard rain gauges", and they are the design used in the UK national network for monitoring precipitation composition. "Dry + wet" deposition collectors are flushing rain gauges and they are equipped with a rain detector (conductivity array), a spray nozzle, a 2-way valve and two independent bottles to collect funnel washings (dry deposition) and true wet deposition. On average, for the 27 weekly samples with 3 valid replicates for the 2 types of collectors, dissolved organic nitrogen (DON) represented 23% of the total dissolved nitrogen (TDN) in bulk deposition. Dry deposition of particles and gas on the funnel surface, rather than rain, contributed over half of all N-containing species (inorganic and organic). Some discrepancies were found between bulk rain gauges and flushing rain gauges, for deposition of both TDN and DON, suggesting biological conversion and loss of inorganic N in the flushing samplers.
Impact of managed moorland burning on peat nutrient and base cation status
NASA Astrophysics Data System (ADS)
Palmer, Sheila; Gilpin, Martin; Wearing, Catherine; Johnston, Kerrylyn; Holden, Joseph; Brown, Lee
2013-04-01
Controlled 'patch' burning of moorland vegetation has been used for decades in the UK to stimulate growth of heather (Calluna vulgaris) for game bird habitat and livestock grazing. Typically small patches (300-900 m2) are burned in rotations of 8-25 years. However, our understanding of the short-to-medium term environmental impacts of the practice on these sensitive upland areas has so far been limited by a lack of scientific data. In particular the effect of burning on concentrations of base cations and acid-base status of these highly organic soils has implications both for ecosystem nutrient status and for buffering of acidic waters. As part of the EMBER project peat chemistry data were collected in ten upland blanket peat catchments in the UK. Five catchments were subject to a history of prescribed rotational patch burning. The other five catchments acted as controls which were not subject to burning, nor confounded by other detrimental activities such as drainage or forestry. Soil solution chemistry was also monitored at two intensively studied sites (one regularly burned and one control). Fifty-centimetre soil cores, sectioned into 5-cm intervals, were collected from triplicate patches of four burn ages at each burned site, and from twelve locations at similar hillslope positions at each control site. At the two intensively monitored sites, soil solution chemistry was monitored at four depths in each patch. Across all sites, burned plots had significantly smaller cation exchange capacities, lower concentrations of exchangeable base cations and increased concentrations of exchangeable H+ and Al3+ in near-surface soil. C/N ratios were also lower in burned compared to unburned surface soils. There was no consistent trend between burn age and peat chemistry across all burned sites, possibly reflecting local controls on post-burn recovery rates or external influences on burn management decisions. At the intensively monitored site, plots burned less than two years prior to sampling had significantly smaller exchange capacities and lower concentrations of soil base cations in surface soils relative to plots burned 15-25 years previously. In contrast, surface soil solutions in recently burned plots were enriched in base cations relative to older plots and relative to the control site, possibly due to enhanced leaching at bare soil surfaces. The results offer evidence for an impact of burning on peat nutrient and acid-base status, but suggest that soils recover given time with no further burning.
Misson-Yates, S; Gonzalez, R; McGovern, M; Greener, A
2015-05-01
This article describes the external audit measurements conducted in two UK centres implementing total skin electron beam therapy (TSEBT) and the results obtained. Measurements of output, energy, beam flatness and symmetry at a standard distance (95 or 100 cm SSD) were performed using a parallel plate chamber in solid water. Similarly, output and energy measurements were also performed at the treatment plane for single and dual fields. Clinical simulations were carried out using thermoluminescent dosemeters (TLDs) and Gafchromic® film (International Specialty Products, Wayne, NJ) on an anthropomorphic phantom. Extended distance measurements confirmed that local values for the beam dosimetry at Centres A and B were within 2% for outputs and 1-mm agreement of the expected depth at which the dose is 50% of the maximum for the depth-dose curve in water (R50,D) value. Clinical simulation using TLDs) showed an agreement of -1.6% and -6.7% compared with the expected mean trunk dose for each centre, respectively, and a variation within 10% (±1 standard deviation) across the trunk. The film results confirmed that the delivery of the treatment technique at each audited centre complies with the European Organisation for Research and Treatment of Cancer recommendations. This audit methodology has proven to be a successful way to confirm the agreement of dosimetric parameters for TSEBT treatments at both audited centres and could serve as the basis for an audit template to be used by other audit groups. TSEBT audits are not established in the UK owing to a limited number of centres carrying out the treatment technique. This article describes the audits performed at two UK centres prior to their clinical implementation.
Gonzalez, R; McGovern, M; Greener, A
2015-01-01
Objective: This article describes the external audit measurements conducted in two UK centres implementing total skin electron beam therapy (TSEBT) and the results obtained. Methods: Measurements of output, energy, beam flatness and symmetry at a standard distance (95 or 100 cm SSD) were performed using a parallel plate chamber in solid water. Similarly, output and energy measurements were also performed at the treatment plane for single and dual fields. Clinical simulations were carried out using thermoluminescent dosemeters (TLDs) and Gafchromic® film (International Specialty Products, Wayne, NJ) on an anthropomorphic phantom. Results: Extended distance measurements confirmed that local values for the beam dosimetry at Centres A and B were within 2% for outputs and 1-mm agreement of the expected depth at which the dose is 50% of the maximum for the depth–dose curve in water (R50,D) value. Clinical simulation using TLDs) showed an agreement of −1.6% and −6.7% compared with the expected mean trunk dose for each centre, respectively, and a variation within 10% (±1 standard deviation) across the trunk. The film results confirmed that the delivery of the treatment technique at each audited centre complies with the European Organisation for Research and Treatment of Cancer recommendations. Conclusion: This audit methodology has proven to be a successful way to confirm the agreement of dosimetric parameters for TSEBT treatments at both audited centres and could serve as the basis for an audit template to be used by other audit groups. Advances in knowledge: TSEBT audits are not established in the UK owing to a limited number of centres carrying out the treatment technique. This article describes the audits performed at two UK centres prior to their clinical implementation. PMID:25761213
Trajectories of ecosystem service change in restored peatlands
NASA Astrophysics Data System (ADS)
Evans, Martin; Shuttleworth, Emma; Pilkington, Mike; Allott, Tim; Walker, Jonathan; Spencer, Tom
2017-04-01
Peatlands provide a wide range of ecosystem services but across the world degradation of these systems through a range of human impacts has had a negative effect on the provision of these services. A wide variety of peatland restoration approaches have been developed with the aim of mitigating these impacts. Understanding of trajectories of change in ecosystem structure and function is central to evaluating the efficacy of these restoration methods. This paper considers data on post-restoration trajectories of water table change, vegetation recovery, runoff production and water quality based on extensive data from peatland restoration work in the southern Pennines of the U.K. Data have been compiled from multiple restoration initiatives undertaken across the region, spanning up to 12 years post restoration. The data show variations in the time scale of ecosystem change which are indicative of the process basis of the ecosystem trajectories. Rapid changes in runoff are controlled by physical changes to the peatland surface. These are contrasted with longer term evolution of vegetation and water table behaviour which suggest ongoing recovery as the ecosystem adjusts to the restoration process. In order to assess restoration of ecosystem function, and so of ecosystem services, it is important that the process links between ecosystem structure and function are well understood. Establishing typical restoration trajectories can be of practical use in determining restoration project milestones, and can also provide insight into the nature of these process links.
Risk-based water resources planning: Incorporating probabilistic nonstationary climate uncertainties
NASA Astrophysics Data System (ADS)
Borgomeo, Edoardo; Hall, Jim W.; Fung, Fai; Watts, Glenn; Colquhoun, Keith; Lambert, Chris
2014-08-01
We present a risk-based approach for incorporating nonstationary probabilistic climate projections into long-term water resources planning. The proposed methodology uses nonstationary synthetic time series of future climates obtained via a stochastic weather generator based on the UK Climate Projections (UKCP09) to construct a probability distribution of the frequency of water shortages in the future. The UKCP09 projections extend well beyond the range of current hydrological variability, providing the basis for testing the robustness of water resources management plans to future climate-related uncertainties. The nonstationary nature of the projections combined with the stochastic simulation approach allows for extensive sampling of climatic variability conditioned on climate model outputs. The probability of exceeding planned frequencies of water shortages of varying severity (defined as Levels of Service for the water supply utility company) is used as a risk metric for water resources planning. Different sources of uncertainty, including demand-side uncertainties, are considered simultaneously and their impact on the risk metric is evaluated. Supply-side and demand-side management strategies can be compared based on how cost-effective they are at reducing risks to acceptable levels. A case study based on a water supply system in London (UK) is presented to illustrate the methodology. Results indicate an increase in the probability of exceeding the planned Levels of Service across the planning horizon. Under a 1% per annum population growth scenario, the probability of exceeding the planned Levels of Service is as high as 0.5 by 2040. The case study also illustrates how a combination of supply and demand management options may be required to reduce the risk of water shortages.
Bio and nanomaterials in tribocorrosion systems
NASA Astrophysics Data System (ADS)
Benea, Lidia
2017-02-01
The growing attention that the scientific community has paid in the last decades to the corrosion phenomena, including tribocorrosion is related to the huge economic, social and environmental losses (3,5 % GDP in industrialized countries as USA, UK, Japan and Germany), that result from the spread of damage of several metal constructions and devices. Tribocorrosion is defined as the chemical-electrochemical-mechanical process leading to a degradation of materials in sliding, rolling or erosion contacts immersed in a corrosive environment or even in water. That degradation results from the combined action of corrosion and wear are higher compared with addition of corrosion and wear degradation separately. This synergism between chemical, electrochemical, and mechanical processes on materials in sliding, abrasive or erosive contacts immersed in a liquid requires a multi-disciplinary approach (material science, electrochemistry, tribology, mechanics, and surface engineering). This paper presents few summary results obtained by studying the materials degradation by complex tribocorrosion processes in terms of two broad categories of applications: tribocorrosion in industrial systems with improved behaviour of nanomaterials as hybrid and nanocomposite layers and tribocorrosion in living systems with improved behaviour by surface modifications of biomaterials applying electrochemical techniques. The purpose of this paper is to provide information on the surface conditions of materials in sliding contacts and also on the kinetics of reactions that control the corrosion component in the material loss during tribocorrosion tests.
The different modes of hydro-economic analysis (Invited)
NASA Astrophysics Data System (ADS)
Harou, J. J.; Binions, O.; Erfani, T.
2013-12-01
In the face of growing water demands, climate change and spatial and temporal water access variability, accurately assessing the economic impacts of proposed water resource management changes is useful. The objective of this project funded by UK Water Industry Research was to present and demonstrate a framework for identifying and using the ';value of water' to enable water utilities and their regulators to make better decisions. A hydro-economic model can help evaluate water management options in terms of their hydrological and economic impact at different locations throughout a catchment over time. In this talk we discuss three modes in which hydro-economic models can be implemented: evaluative, behavioral and prescriptive. In evaluation mode economic water demand and benefit functions are used to post-process water resource management model results to assess the economic impacts (over space and time) of a policy under consideration. In behavioral hydro-economic models users are represented as agents and the economics is used to help predict their actions. In prescriptive mode optimization is used to find the most economically efficient management actions such as allocation patterns or source selection. These three types of hydro-economic analysis are demonstrated on a UK watershed (Great River Ouse) that includes 97 different water abstractors from amongst the public water supply, agriculture, industry and energy plant cooling sectors. The following issues under dry and normal historical conditions were investigated: Supply/demand investment planning, societal cost of environmental flows, water market prices, and scarcity-sensitive charges for water rights. The talk discusses which hydro-economic modeling mode is used to study each of these issues and why; example results are shown and discussed. The topic of how hydro-economic models can be built and deployed effectively is covered along with how existing water utility operational and planning tools can be converted into hydro-economic models.
Astaraie-Imani, Maryam; Kapelan, Zoran; Fu, Guangtao; Butler, David
2012-12-15
Climate change and urbanisation are key factors affecting the future of water quality and quantity in urbanised catchments and are associated with significant uncertainty. The work reported in this paper is an evaluation of the combined and relative impacts of climate change and urbanisation on the receiving water quality in the context of an Integrated Urban Wastewater System (IUWS) in the UK. The impacts of intervening system operational control parameters are also investigated. Impact is determined by a detailed modelling study using both local and global sensitivity analysis methods together with correlation analysis. The results obtained from the case-study analysed clearly demonstrate that climate change combined with increasing urbanisation is likely to lead to worsening river water quality in terms of both frequency and magnitude of breaching threshold dissolved oxygen and ammonium concentrations. The results obtained also reveal the key climate change and urbanisation parameters that have the largest negative impact as well as the most responsive IUWS operational control parameters including major dependencies between all these parameters. This information can be further utilised to adapt future IUWS operation and/or design which, in turn, should make these systems more resilient to future climate and urbanisation changes. Copyright © 2012 Elsevier Ltd. All rights reserved.
Barber, C M; Wiggans, R E; Carder, M; Agius, R
2017-01-01
Objective To estimate the reported incidence of occupational hypersensitivity pneumonitis (OHP) in the UK and to consider whether the pattern of attributed causation has changed over time. Methods All cases of OHP reported to the SWORD scheme between January 1996 and December 2015 were classified into 1 of 10 categories of the suspected agent. Cases were grouped into four 5-year time periods to examine any changing pattern in incidence or suspected causation. For each time period, the annual incidence was calculated using the estimated number of reported cases and the working population of the UK. Results Between 1996 and 2015, there were 202 actual cases of OHP reported to SWORD, equating to an estimated 818 cases, when adjusting for the sampling ratio. Over this period, the annual UK incidence was 1.4 per million workers. The mean (SD) age of reported cases was 52 (13) years, and cases were four-times more likely to be men than women. Over the study period, there was a fall in the proportion of cases reported to be due to agricultural exposures (44–12%), and an increase in cases due to metalworking fluids (MWFs, 2–45%). Conclusions Over the last 20 years, the incidence of OHP in the UK has been ∼1–2 cases per million workers per year. Working with water-based MWFs is now the most commonly suspected causative exposure for OHP cases reported to the SWORD scheme in the UK. PMID:27919062
UK Environmental Prediction - integration and evaluation at the convective scale
NASA Astrophysics Data System (ADS)
Lewis, Huw; Brunet, Gilbert; Harris, Chris; Best, Martin; Saulter, Andrew; Holt, Jason; Bricheno, Lucy; Brerton, Ashley; Reynard, Nick; Blyth, Eleanor; Martinez de la Torre, Alberto
2015-04-01
It has long been understood that accurate prediction and warning of the impacts of severe weather requires an integrated approach to forecasting. This was well demonstrated in the UK throughout winter 2013/14 when an exceptional run of severe winter storms, often with damaging high winds and intense rainfall led to significant damage from the large waves and storm surge along coastlines, and from saturated soils, high river flows and significant flooding inland. The substantial impacts on individuals, businesses and infrastructure indicate a pressing need to understand better the value that might be delivered through more integrated environmental prediction. To address this need, the Met Office, Centre for Ecology & Hydrology and National Oceanography Centre have begun to develop the foundations of a coupled high resolution probabilistic forecast system for the UK at km-scale. This links together existing model components of the atmosphere, coastal ocean, land surface and hydrology. Our initial focus on a 2-year Prototype project will demonstrate the UK coupled prediction concept in research mode, including an analysis of the winter 2013/14 storms and its impacts. By linking science development to operational collaborations such as the UK Natural Hazards Partnership, we can ensure that science priorities are rooted in user requirements. This presentation will provide an overview of UK environmental prediction activities and an update on progress during the first year of the Prototype project. We will present initial results from the coupled model development and discuss the challenges to realise the potential of integrated regional coupled forecasting for improving predictions and applications.
The bedrock electrical conductivity map of the UK
NASA Astrophysics Data System (ADS)
Beamish, David
2013-09-01
Airborne electromagnetic (AEM) surveys, when regionally extensive, may sample a wide-range of geological formations. The majority of AEM surveys can provide estimates of apparent (half-space) conductivity and such derived data provide a mapping capability. Depth discrimination of the geophysical mapping information is controlled by the bandwidth of each particular system. The objective of this study is to assess the geological information contained in accumulated frequency-domain AEM survey data from the UK where existing geological mapping can be considered well-established. The methodology adopted involves a simple GIS-based, spatial join of AEM and geological databases. A lithology-based classification of bedrock is used to provide an inherent association with the petrophysical rock parameters controlling bulk conductivity. At a scale of 1:625k, the UK digital bedrock geological lexicon comprises just 86 lithological classifications compared with 244 standard lithostratigraphic assignments. The lowest common AEM survey frequency of 3 kHz is found to provide an 87% coverage (by area) of the UK formations. The conductivities of the unsampled classes have been assigned on the basis of inherent lithological associations between formations. The statistical analysis conducted uses over 8 M conductivity estimates and provides a new UK national scale digital map of near-surface bedrock conductivity. The new baseline map, formed from central moments of the statistical distributions, allows assessments/interpretations of data exhibiting departures from the norm. The digital conductivity map developed here is believed to be the first such UK geophysical map compilation for over 75 years. The methodology described can also be applied to many existing AEM data sets.
Sustainable Drainage, Green Infrastructure or Natural Flood Management - which should you choose?
NASA Astrophysics Data System (ADS)
Wingfield, Thea; Potter, Karen; Jones, Gareth; Spees, Jack; Macdonald, Neil
2016-04-01
River catchments as management units are more effective than administrative boundaries to integrate and coordinate efforts of organisations that utilise and manage water, soil and habitat quality. The UK government announced a pilot integrated water management initiative called, 'The Catchment Based Approach', on World Water Day 2011. After successful trials the scheme was extended to all river catchments in England during the summer of 2013. This policy has been designed to improve the collaboration, partnership and coordination of organisations involved in water and land management through locally led partnership groups. The lead organisations are all charitable bodies with significantly varying levels of experience of stormwater management; a key component of integrated water management and of great concern to communities at risk. These partnerships have implemented a number of Nature Based Solutions, but these have been presented in different ways by the different groups. In the UK there are three terms commonly used to describe Nature Based Solutions for managing the drainage of stormwater: Sustainable Drainage (SuDS), Green Infrastructure (GI) and Natural Flood Management (NFM). The definitions of each refers to the replication of natural hydrological processes in order to slow the flow of water through the landscape. But, there has been some concerns as to which of these nature based terms should be applied and why they appear to be used interchangeably. This study demonstrates that, despite the definitions of these three terms being almost identical, in practice they are not the same and should not be used interchangeably. The terms were developed by different professional groups in response to their own objectives and histories. The hydrological processes used to manage storm-water may be the same and the suggested interventions may show a degree of convergence. Yet, they operate at different scales, both geographically and organisationally. The different professional disciplines have their own ideologies and work to distinct governing regulations which manage and perceive operational risk in varying ways. All of these factors lead to storm-water nature based solutions not just being applied differently within a catchment but viewed and understood differently by organisations that are working in partnership. The catchment partnerships will be better equipped to incorporate or employ nature based storm water management in the UK through this research. By understanding the factors and agents behind the development of SuDS, GI and NFM and providing ways in which to visualise and communicate this at a catchment level it is hoped to reduce some of the barriers to their practical implementation.
Improving the Fit of a Land-Surface Model to Data Using its Adjoint
NASA Astrophysics Data System (ADS)
Raoult, N.; Jupp, T. E.; Cox, P. M.; Luke, C.
2015-12-01
Land-surface models (LSMs) are of growing importance in the world of climate prediction. They are crucial components of larger Earth system models that are aimed at understanding the effects of land surface processes on the global carbon cycle. The Joint UK Land Environment Simulator (JULES) is the land-surface model used by the UK Met Office. It has been automatically differentiated using commercial software from FastOpt, resulting in an analytical gradient, or 'adjoint', of the model. Using this adjoint, the adJULES parameter estimation system has been developed, to search for locally optimum parameter sets by calibrating against observations. adJULES presents an opportunity to confront JULES with many different observations, and make improvements to the model parameterisation. In the newest version of adJULES, multiple sites can be used in the calibration, to giving a generic set of parameters that can be generalised over plant functional types. We present an introduction to the adJULES system and its applications to data from a variety of flux tower sites. We show that calculation of the 2nd derivative of JULES allows us to produce posterior probability density functions of the parameters and how knowledge of parameter values is constrained by observations.
NASA Astrophysics Data System (ADS)
Hall, J. W.; Mortazavi-Naeini, M.; Coxon, G.; Guillod, B. P.; Allen, M. R.
2017-12-01
Water resources systems can fail to deliver the services required by water users (and deprive the environment of flow requirements) in many different ways. In an attempt to make systems more resilient, they have also been made more complex, for example through a growing number of large-scale transfers, optimized storages and reuse plants. These systems may be vulnerable to complex variants of hydrological variability in space and time, and behavioural adaptations by water users. In previous research we have used non-parametric stochastic streamflow generators to test the vulnerability of water resource systems. Here we use a very large ensemble of regional climate model outputs from the weather@home crowd-sourced citizen science project, which has generated more than 30,000 years of synthetic weather for present and future climates in the UK and western Europe, using the HadAM3P regional climate model. These simulations have been constructed in order to preserve prolonged drought characteristics, through treatment of long-memory processes in ocean circulations and soil moisture. The weather simulations have been propagated through the newly developed DynaTOP national hydrological for Britain, in order to provide low flow simulations at points of water withdrawal for public water supply, energy and agricultural abstractors. We have used the WATHNET water resource simulation model, set up for the Thames Basin and for all of the large water resource zones in England, to simulate the frequency, severity and duration of water shortages in all of these synthetic weather conditions. In particular, we have sought to explore systemic vulnerabilities associated with inter-basin transfers and the trade-offs between different water users. This analytical capability is providing the basis for (i) implementation of the Duty of Resilience, which has been placed upon the water industry in the 2014 Water Act and (ii) testing reformed abstraction arrangements which the UK government is committed to implementing.
NASA Astrophysics Data System (ADS)
Ferrer, Nuria; Folch, Albert; Lane, Mike; Thomas, Mike; Sasaka, Willie; Wara, Calvince; Banje, Said; Olago, Dan; Katuva, Jacob; Thomson, Patrick; Hope, Rob
2016-04-01
The population growth in the world carries on the one hand, an increased demand of fresh water and on the other hand, a decrease of quality and quantity of this resource. To avoid this deterioration it is essential doing a good management of surface water and groundwater, specially the second one, which has become the major source of water supply for domestic, industrial and agricultural sectors of many countries (UNEP 1999). This groundwater management starts with an accurate hydrogeological characterization of aquifer systems, mainly in that aquifer systems in which is changing the abstraction regime. In this context of population growth and new abstraction regimes on aquifer system is where the project "Gro for Good: Groundwater Risk for Growth and Development" is founded by UPGro. This interdisciplinary project has the main goal to design, test and transfer to the society an innovative Groundwater Risk Management Tool to improve and get by new governance transformations the balance between economic growth, groundwater sustainability (in terms of quality and quantity) and human development (http://upgro.org/consortium/gro-for-good/). The study area is located on the south eastern coast of Kenya, in Kwale County. The Kwale coastal groundwater system formed by a shallow and deep aquifer systems has long served urban water demands and an established tourism industry but now faces unprecedented ground and surface water resource demands especially from KISCOL's (5,500 hectares of irrigated sugarcane) and the country's largest mining operation (Base Titanium Ltd.). Despite both companies have drilled deep boreholes around the study area (416 km2) to extract groundwater from deep aquifer; no major pumping activity has started yet, allowing baseline evaluation. Scattered around the study are 440 handpumps providing drinking water to over 90,000 people. The relationship between the shallow and deep aquifers remains uncertain and so, the future influence on groundwater level and its quality either. So, in order to define the system and start to understand the different complex interactions, we present the initial results of the first complete water sampling field campaign (September 2015). Water isotope data and major ions were analyzed from 78 shallow and deep wells and surface water spread around study area. This field survey has been useful to understand the recharge, discharge areas and groundwater quality of deep aquifer system and which will have an important role for sustainable water management in the of Kwale area. Acknowledgements The research is primarily supported under the NERC/ESRC/DFID Unlocking the Potential of Groundwater for the Poor (UPGro) as a Catalyst Grant (NE/L001950/1) with work extending until 2019 as a Consortium Grant (NE/M008894/1), see http://www.upgro.org. Data for the paper will be publicly posted on the National Geoscience Data Centre and the UK Data Archive under the terms of the UPGro data management agreement.
Ascott, M J; Gooddy, D C; Lapworth, D J; Stuart, M E
2016-12-01
Understanding sources of phosphorus (P) to the environment is critical for the management of freshwater and marine ecosystems. Phosphate is added at water treatment works for a variety of reasons: to reduce pipe corrosion, to lower dissolved lead and copper concentrations at customer's taps and to reduce the formation of iron and manganese precipitates which can lead to deterioration in the aesthetic quality of water. However, the spatial distribution of leakage into the environment of phosphate added to mains water for plumbosolvency control has not been quantified to date. Using water company leakage rates, leak susceptibility and road network mapping, we quantify the total flux of P from leaking water mains in England and Wales at a 1km grid scale. This is validated against reported leaks for the UKs largest water utility. For 2014, we estimate the total flux of P from leaking mains to the environment to be c. 1.2ktP/year. Spatially, P flux is concentrated in urban areas where pipe density is highest, with major cities acting as a significant source of P (e.g. London into the Thames, with potentially 30% of total flux). The model suggests the majority (69%) of the P flux is likely to be to surface water. This is due to leakage susceptibility being a function of soil corrosivity and shrink-swell behaviour which are both controlled by presence of low-permeability clays. The location of major cities such as London close to the coast results in a potentially significant flux of P from mains leakage to estuarine environments. The contribution of leakage of phosphate dosed mains water should be considered in future source apportionment and ecosystem management. The methodology presented is generic and can be applied in other countries where phosphate dosing is undertaken or used prior to dosing during investment planning. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Neill, Aaron; Tetzlaff, Doerthe; Strachan, Norval; Hough, Rupert; Soulsby, Chris
2016-04-01
In order to comply with legislation such as the Water Framework Directive and to safeguard public health, there is a critical need to maintain the quality of water sources that are used to supply drinking water. Private water supplies (PWS) are still common in many rural areas in the UK, and are especially vulnerable to poor water quality, owing to the limited treatment they often receive and variable raw water quality in groundwater and surface water sources. A significant issue affecting PWS quality is contamination by faecal pathogens derived from grazing animals or agricultural practices. In Scotland, approximately 20,000 PWS serve around 200,000 people, with a number of these PWS consistently failing to meet water quality targets relating to coliform bacteria and E. coli, both of which can be indicative of faecal contamination (faecal indicator organisms - FIOs). The purpose of our study was to employ integrated empirical and modelling approaches from hydrology and microbiology to elucidate the nature of the still poorly-understood interplay between hydrological flow pathways which connect sources of pathogens to PWS sources, antecedent conditions, seasonality and pathogen transfer risk, for two catchments with contrasting land uses in Scotland: an agricultural catchment (Tarland Burn) and a montane catchment (Bruntland Burn). In the Tarland Burn, 15 years of spatially-distributed samples collected at the catchment-scale of FIO counts were analysed alongside hydrometric data to identify "hot spots" of faecal pathogen transfer risk and possible spatial and temporal controls. We also used a combination of tracer-based and numerical modelling approaches to identify the relationship between hydrological connectivity, flow pathways, and the mobilisation of faecal pathogens from different sources. In the Bruntland Burn, we coupled a pathogen storage, mobilisation and transport scheme to a previously developed tracer-informed hydrological model for the catchment to investigate temporal patterns and controls of pathogen transfer risk from different hydrological source areas identified from extensive past tracer and numerical modelling work: groundwater, hillslopes and the dynamic riparian zone.
NASA Astrophysics Data System (ADS)
Orr, John; Ibell, Timothy; Evernden, Mark; Darby, Antony
2015-05-01
Emissions reductions targets for the UK set out in the Climate Change Act for the period to 2050 will only be achieved with significant changes to the built environment, which is currently estimated to account for 50% of the UK's carbon emissions. The socio-technological nature of Civil Engineering means that this field is uniquely placed to lead the UK through such adaptations. This paper discusses the importance of interdisciplinary teaching to produce multi-faceted team approaches to sustainable design solutions. Methods for measuring success in education are often not fit for purpose, producing good students but poor engineers. Real-world failures to apply sustainable design present a serious, difficult to detect, and ultimately economically negative situation. Techniques to replace summative examinations are presented and discussed, with the aim of enhancing core technical skills alongside those required for sustainable design. Finally, the role of our future engineers in policy-making is discussed. In addition to carbon, the provision of water and food will heavily influence the work of civil engineers in the coming decades. Leadership from civil engineers with the technical knowledge and social awareness to tackle these issues will be required. This provides both opportunities and challenges for engineering education in the UK.
NASA Astrophysics Data System (ADS)
Ribeiro Neto, A.; Scott, C. A.; Lima, E. A.; Montenegro, S. M. G. L.; Cirilo, J. A.
2014-09-01
Water availability for a range of human uses will increasingly be affected by climate change, especially in the arid and semiarid tropics. The main objective of this study is to evaluate the infrastructure sufficiency in meeting water demand under climate-induced socio-hydrological transition in the Capibaribe River basin (CRB). The basin has experienced spatial and sectoral (agriculture-to-urban) reconfiguration of water demands. Human settlements that were once dispersed, relying on intermittent sources of surface water, are now larger and more spatially concentrated, which increases water-scarcity effects. Based on the application of linked hydrologic and water-resources models using precipitation and temperature projections of the IPCC SRES (Special Report: Emissions Scenarios) A1B scenario, a reduction in rainfall of 26.0% translated to streamflow reduction of 60.0%. We used simulations from four members of the HadCM3 (UK Met Office Hadley Centre) perturbed physics ensemble, in which a single model structure is used and perturbations are introduced to the physical parameterization schemes in the model (Chou et al., 2012). We considered that the change of the water availability in the basin in the future scenarios must drive the water management and the development of adaptation strategies that will manage the water demand. Several adaptive responses are considered, including water-loss reductions, wastewater collection and reuse, and rainwater collection cisterns, which together have potential to reduce future water demand by 23.0%. This study demonstrates the vulnerabilities of the infrastructure system during socio-hydrological transition in response to hydroclimatic and demand variabilities in the CRB and also indicates the differential spatial impacts and vulnerability of multiple uses of water to changes over time. The simulations showed that the measures proposed and the water from interbasin transfer project of the São Francisco River had a positive impact over the water supply in the basin, mainly for human use. Industry and irrigation will suffer impact unless other measures are implemented for demand control.
Kotaka, Atsushi; Bando, Hiroki; Kaya, Masahiko; Kato-Murai, Michiko; Kuroda, Kouichi; Sahara, Hiroshi; Hata, Yoji; Kondo, Akihiko; Ueda, Mitsuyoshi
2008-06-01
Three beta-glucosidase- and two endoglucanase-encoding genes were cloned from Aspergillus oryzae, and their gene products were displayed on the cell surface of the sake yeast, Saccharomyces cerevisiae GRI-117-UK. GRI-117-UK/pUDB7 displaying beta-glucosidase AO090009000356 showed the highest activity against various substrates and efficiently produced ethanol from cellobiose. On the other hand, GRI-117-UK/pUDCB displaying endoglucanase AO090010000314 efficiently degraded barley beta-glucan to glucose and smaller cellooligosaccharides. GRI-117-UK/pUDB7CB codisplaying both beta-glucosidase AO090009000356 and endoglucanase AO090010000314 was constructed. When direct ethanol fermentation from 20 g/l barley beta-glucan as a model substrate was performed with the codisplaying strain, the ethanol concentration reached 7.94 g/l after 24 h of fermentation. The conversion ratio of ethanol from beta-glucan was 69.6% of the theoretical ethanol concentration produced from 20 g/l barley beta-glucan. These results showed that sake yeast displaying A. oryzae cellulolytic enzymes can be used to produce ethanol from cellulosic materials. Our constructs have higher ethanol production potential than the laboratory constructs previously reported.
Horton, Alice A; Svendsen, Claus; Williams, Richard J; Spurgeon, David J; Lahive, Elma
2017-01-15
Sewage effluent input and population were chosen as predictors of microplastic presence in sediments at four sites in the River Thames basin (UK). Large microplastic particles (1mm-4mm) were extracted using a stepwise approach to include visual extraction, flotation and identification using Raman spectroscopy. Microplastics were found at all four sites. One site had significantly higher numbers of microplastics than other sites, average 66 particles 100g -1 , 91% of which were fragments. This site was downstream of a storm drain outfall receiving urban runoff; many of the fragments at this site were determined to be derived of thermoplastic road-surface marking paints. At the remaining three sites, fibres were the dominant particle type. The most common polymers identified included polypropylene, polyester and polyarylsulphone. This study describes two major new findings: presence of microplastic particles in a UK freshwater system and identification of road marking paints as a source of microplastics. This study is the first to quantify microplastics of any size in river sediments in the UK and links their presence to terrestrial sources including sewage and road marking paints. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.
A multi-proxy reconstruction of millennial scale drought history for Northern England
NASA Astrophysics Data System (ADS)
Macdonald, Dr; Chiverrell, Dr; Hind, Ms; Todd, Ms; Charman, Dr
2012-04-01
Drought is one of the major natural hazards experienced worldwide; they are complex with both causes and multifaceted impacts poorly understood. Few studies of drought events from a long-term perspective have been undertaken in the UK. This presents problems in determining important drought characteristics such as duration, frequency and severity. In order to undertake robust drought analyses reliable long-term data are required. Historical records have long been recognised as valuable data sources within historical climatology; however, the application of historical records in drought analysis is in its infancy, with few historical studies considering drought. This paper presents a reconstruction of drought events for NW England, from around AD 1000 to 2009, drawing upon instrumental, historical and sedimentary records. The drought record is extended to a millennial timescale by coupling the long, continuous instrumental meteorological records available for this area since the late 18th century, with descriptive historical accounts of droughts (since c.AD 1600) and a sedimentary peat sequences from an ombrotrophic mire (Butterburn Flow), where a water table variation history has been inferred from sub-fossil testate amoebae. The testate amoebae analyses were undertaken at 3mm sampling resolution, providing a sub-decadal (2-5 year) sample resolution. Calibration of the sedimentary sequences to the instrument series over the last c.250 years, coupled with chronological control provided by air fall pollutants (Pb and Zn) histories and radiocarbon dating, reveals a detailed millennial drought-dry phase history. The results identify a number of severe droughts - dry phases that have been of longer duration and of greater severity than the 1976 drought, the most memorable drought in living memory in the UK. The results of this work illustrate that current water resource management plans within the UK would struggle to maintain potable water supplies, indicating the need for greater resilience within current water management plans.
Defense Acquisition Programs: Status of Selected Systems
1989-12-01
Separation Fyout Events I Chute Deployment a r Broach Events Torpedo Search/Attack Tp WtEr . Guidance Limits Torl Water Entry * Engine Start Floatup * Chute...100 general purpose AN/UK-4450 special purpose Power 138 kilowatts Tomahawk ____________________Weight 32 tons Cooling Water 150 gallons/minute Req I...operated outsid(’ V’s. waters . V - (’ lin , t" {I li’,X;I%. 1 il , 77,1 h’Iod 12 t~lwpc( w ’ %.% ith 119 tli d i a ’ .’]H I cf 41 ll i.( lff;il( I;k
NASA Astrophysics Data System (ADS)
Howden, N. J. K.; Burt, T.; Worrall, F.
2016-12-01
The UK has a wealth of hydrological monitoring data that has both good coverage in space since the early 1970s, and also a few locations where records have been kept continuously for almost 150 years. Such datasets offer unique opportunities for the hydrologist to consider how the concepts of stationarity, change, and definitions of "baseline" resources should be used to shape how we build models of these systems, and how we devise appropriate and sustainable watershed management strategies. In this paper we consider some of the UK's longest hydrological and biogeochemical records, to explore how long records can be used to shape such understanding and, in some cases, how they can be used to identify new modes of behaviour that need to be incorporated into management planning, from the scale of individual watersheds right up to the national scale. We also consider how key timescales of hydrological responses that are evident within the data may pose major problems for watershed management unless appropriate attention is paid to the potential impacts of processes that work over decadal timescales - much longer than sub-decadal water industry investment cycles or short-term projects for watershed management planning. We use our long-term records to show how key processes can be identified, and to illustrate how careful interpretation of shorter term records will improve decision-making for water resource management.
How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?
Zięba, Grzegorz; Fox, Michael G.; Copp, Gordon H.
2015-01-01
Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts) appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime. PMID:26302021
NASA Astrophysics Data System (ADS)
Aleksankina, Ksenia; Heal, Mathew R.; Dore, Anthony J.; Van Oijen, Marcel; Reis, Stefan
2018-04-01
Atmospheric chemistry transport models (ACTMs) are widely used to underpin policy decisions associated with the impact of potential changes in emissions on future pollutant concentrations and deposition. It is therefore essential to have a quantitative understanding of the uncertainty in model output arising from uncertainties in the input pollutant emissions. ACTMs incorporate complex and non-linear descriptions of chemical and physical processes which means that interactions and non-linearities in input-output relationships may not be revealed through the local one-at-a-time sensitivity analysis typically used. The aim of this work is to demonstrate a global sensitivity and uncertainty analysis approach for an ACTM, using as an example the FRAME model, which is extensively employed in the UK to generate source-receptor matrices for the UK Integrated Assessment Model and to estimate critical load exceedances. An optimised Latin hypercube sampling design was used to construct model runs within ±40 % variation range for the UK emissions of SO2, NOx, and NH3, from which regression coefficients for each input-output combination and each model grid ( > 10 000 across the UK) were calculated. Surface concentrations of SO2, NOx, and NH3 (and of deposition of S and N) were found to be predominantly sensitive to the emissions of the respective pollutant, while sensitivities of secondary species such as HNO3 and particulate SO42-, NO3-, and NH4+ to pollutant emissions were more complex and geographically variable. The uncertainties in model output variables were propagated from the uncertainty ranges reported by the UK National Atmospheric Emissions Inventory for the emissions of SO2, NOx, and NH3 (±4, ±10, and ±20 % respectively). The uncertainties in the surface concentrations of NH3 and NOx and the depositions of NHx and NOy were dominated by the uncertainties in emissions of NH3, and NOx respectively, whilst concentrations of SO2 and deposition of SOy were affected by the uncertainties in both SO2 and NH3 emissions. Likewise, the relative uncertainties in the modelled surface concentrations of each of the secondary pollutant variables (NH4+, NO3-, SO42-, and HNO3) were due to uncertainties in at least two input variables. In all cases the spatial distribution of relative uncertainty was found to be geographically heterogeneous. The global methods used here can be applied to conduct sensitivity and uncertainty analyses of other ACTMs.
The sensitivities of emissions reductions for the mitigation of UK PM2.5
NASA Astrophysics Data System (ADS)
Vieno, M.; Heal, M. R.; Williams, M. L.; Carnell, E. J.; Nemitz, E.; Stedman, J. R.; Reis, S.
2016-01-01
The reduction of ambient concentrations of fine particulate matter (PM2.5) is a key objective for air pollution control policies in the UK and elsewhere. Long-term exposure to PM2.5 has been identified as a major contributor to adverse human health effects in epidemiological studies and underpins ambient PM2.5 legislation. As a range of emission sources and atmospheric chemistry transport processes contribute to PM2.5 concentrations, atmospheric chemistry transport models are an essential tool to assess emissions control effectiveness. The EMEP4UK atmospheric chemistry transport model was used to investigate the impact of reductions in UK anthropogenic emissions of primary PM2.5, NH3, NOx, SOx or non-methane VOC on surface concentrations of PM2.5 in the UK for a recent year (2010) and for a future current legislation emission (CLE) scenario (2030). In general, the sensitivity to UK mitigation is rather small. A 30 % reduction in UK emissions of any one of the above components yields (for the 2010 simulation) a maximum reduction in PM2.5 in any given location of ˜ 0.6 µg m-3 (equivalent to ˜ 6 % of the modelled PM2.5). On average across the UK, the sensitivity of PM2.5 concentrations to a 30 % reduction in UK emissions of individual contributing components, for both the 2010 and 2030 CLE baselines, increases in the order NMVOC, NOx, SOx, NH3 and primary PM2.5; however there are strong spatial differences in the PM2.5 sensitivities across the UK. Consequently, the sensitivity of PM2.5 to individual component emissions reductions varies between area and population weighting. Reductions in NH3 have the greatest effect on area-weighted PM2.5. A full UK population weighting places greater emphasis on reductions of primary PM2.5 emissions, which is simulated to be the most effective single-component control on PM2.5 for the 2030 scenario. An important conclusion is that weighting corresponding to the average exposure indicator metric (using data from the 45 model grids containing a monitor whose measurements are used to calculate the UK AEI) further increases the emphasis on the effectiveness of primary PM2.5 emissions reductions (and of NOx emissions reductions) relative to the effectiveness of NH3 emissions reductions. Reductions in primary PM2.5 have the largest impact on the AEI in both 2010 and the 2030 CLE scenario. The summation of the modelled reductions to the UK PM2.5 AEI from 30 % reductions in UK emissions of primary PM2.5, NH3, SOx, NOx and VOC totals 1.17 and 0.82 µg m-3 for the 2010 and 2030 CLE simulations, respectively (not accounting for non-linearity).
NASA Astrophysics Data System (ADS)
Mijic, Ana; Ossa-Moreno, Juan; Smith, Karl M.
2016-04-01
The increased frequency of extreme weather events associated with climate change poses a significant threat to the integrity and function of critical urban infrastructure - rail, road, telecommunications, power and water supply/sewerage networks. A key threat within the United Kingdom (UK) is the increased risk of pluvial flooding; the conventional approach of channeling runoff to an outfall has proven to be unsustainable during severe storm events. Green infrastructure, in the form of Sustainable Urban Drainage Systems (SuDS), has been proposed as a means of minimising the risk of pluvial flooding. However, despite their technical performance, SuDS uptake in the UK has not reached its full capacity yet, mostly due to reasons that go beyong the engineering realm. This work investigated the strategic role of SuDS retrofit in managing environmental risks to urban infrastructure in London at a catchment level, through an economic appraisal of multifunctional benefits. It was found that by including the multifunctional benefits of SuDS, the economic feasibility of the project improves considerably. The case study has also shown a mechanism towards achieving wider-scale SuDS retrofit, whereby the investments are split amongst multiple stakeholder groups by highlighting the additional benefits each group derives. Groups include water utilities and their users, local government and critical infrastructure owners. Finally, limitations to the existing cost-benefit methdology in the UK were identified, and recommendations made regarding incentives and governmental regulations to enhance the uptake of SuDS in London. The proposed methodology provides compelling and robust, cost-benefit based evidence of SUDS' effectiveness within the flood risk management planning framework, but also with regard to the additional benefits of Nature Based Solutions in urban environments.
Revising Hydrology of a Land Surface Model
NASA Astrophysics Data System (ADS)
Le Vine, Nataliya; Butler, Adrian; McIntyre, Neil; Jackson, Christopher
2015-04-01
Land Surface Models (LSMs) are key elements in guiding adaptation to the changing water cycle and the starting points to develop a global hyper-resolution model of the terrestrial water, energy and biogeochemical cycles. However, before this potential is realised, there are some fundamental limitations of LSMs related to how meaningfully hydrological fluxes and stores are represented. An important limitation is the simplistic or non-existent representation of the deep subsurface in LSMs; and another is the lack of connection of LSM parameterisations to relevant hydrological information. In this context, the paper uses a case study of the JULES (Joint UK Land Environmental Simulator) LSM applied to the Kennet region in Southern England. The paper explores the assumptions behind JULES hydrology, adapts the model structure and optimises the coupling with the ZOOMQ3D regional groundwater model. The analysis illustrates how three types of information can be used to improve the model's hydrology: a) observations, b) regionalized information, and c) information from an independent physics-based model. It is found that: 1) coupling to the groundwater model allows realistic simulation of streamflows; 2) a simple dynamic lower boundary improves upon JULES' stationary unit gradient condition; 3) a 1D vertical flow in the unsaturated zone is sufficient; however there is benefit in introducing a simple dual soil moisture retention curve; 4) regionalized information can be used to describe soil spatial heterogeneity. It is concluded that relatively simple refinements to the hydrology of JULES and its parameterisation method can provide a substantial step forward in realising its potential as a high-resolution multi-purpose model.
NASA Astrophysics Data System (ADS)
Howden, Nicholas J. K.; Burt, Tim P.; Worrall, Fred; Mathias, Simon; Whelan, Mick J.
2011-06-01
Widespread pollution of groundwater by nutrients due to 20th century agricultural intensification has been of major concern in the developed world for several decades. This paper considers the River Thames catchment (UK), where water-quality monitoring at Hampton (just upstream of London) has produced continuous records for nitrate for the last 140 years, the longest continuous record of water chemistry anywhere in the world. For the same period, data are available to characterize changes in both land use and land management at an annual scale. A modeling approach is used that combines two elements: an estimate of nitrate available for leaching due to land use and land management; and, an algorithm to route this leachable nitrate through to surface or groundwaters. Prior to agricultural intensification at the start of World War II, annual average inputs were around 50 kg ha-1, and river concentrations were stable at 1 to 2 mg l-1, suggesting in-stream denitrification capable of removing 35 (±15) kt N yr-1. Postintensification data suggest an accumulation of 100 (±40) kt N yr-1 in the catchment, most of which is stored in the aquifer. This build up of reactive N species within the catchments means that restoration of surface nitrate concentrations typical of the preintensification period would require massive basin-wide changes in land use and management that would compromise food security and take decades to be effective. Policy solutions need to embrace long-term management strategies as an urgent priority.
NASA Astrophysics Data System (ADS)
Humphreys, Matthew; Moore, Mark; Achterberg, Eric; Chowdhury, Mohammed; Griffiths, Alex; Hartman, Susan; Hopkins, Joanne; Hull, Tom; Kivimäe, Caroline; Sivyer, Dave; Smilenova, Angelina; Wihsgott, Juliane; Woodward, Malcolm
2017-04-01
Continental shelf seas support 15-20% of global primary productivity despite covering only about 5% of the Earth's ocean surface area. As a result, they may have a significant role in oceanic uptake and storage of carbon dioxide (CO2) from the atmosphere, through the 'continental shelf pump' mechanism. The northwest European continental shelf, in particular the Celtic Sea (50°N 8°W), was the target of extensive biogeochemical sampling from March 2014 to September 2015, as part of the UK Shelf Sea Biogeochemistry research programme (UK-SSB). Here, we use the UK-SSB carbonate chemistry and macronutrient measurements to investigate the biogeochemical seasonality in the temperate, seasonally-stratifying Celtic Sea. During the spring-summer, near-surface biological activity removed dissolved inorganic carbon and nutrients, some of which were then exported into the deeper layer. We calculated vertical inventories of these variables throughout 1.5 seasonal cycles and attempted to correct these for air-sea CO2 exchange, advection and denitrification, thus isolating the combined effect of net community production and remineralisation on the inorganic macronutrient inventories, and revealing fluctuating deviations from Redfield stoichiometry. Here, we discuss the capacity of these stoichiometric inconsistencies to sustain the Celtic Sea nutrient supply, and thus examine whether an effective continental shelf pump for CO2 could operate in this region.
Hominin footprints from early Pleistocene deposits at Happisburgh, UK.
Ashton, Nick; Lewis, Simon G; De Groote, Isabelle; Duffy, Sarah M; Bates, Martin; Bates, Richard; Hoare, Peter; Lewis, Mark; Parfitt, Simon A; Peglar, Sylvia; Williams, Craig; Stringer, Chris
2014-01-01
Investigations at Happisburgh, UK, have revealed the oldest known hominin footprint surface outside Africa at between ca. 1 million and 0.78 million years ago. The site has long been recognised for the preservation of sediments containing Early Pleistocene fauna and flora, but since 2005 has also yielded humanly made flint artefacts, extending the record of human occupation of northern Europe by at least 350,000 years. The sediments consist of sands, gravels and laminated silts laid down by a large river within the upper reaches of its estuary. In May 2013 extensive areas of the laminated sediments were exposed on the foreshore. On the surface of one of the laminated silt horizons a series of hollows was revealed in an area of ca. 12 m(2). The surface was recorded using multi-image photogrammetry which showed that the hollows are distinctly elongated and the majority fall within the range of juvenile to adult hominin foot sizes. In many cases the arch and front/back of the foot can be identified and in one case the impression of toes can be seen. Using foot length to stature ratios, the hominins are estimated to have been between ca. 0.93 and 1.73 m in height, suggestive of a group of mixed ages. The orientation of the prints indicates movement in a southerly direction on mud-flats along the river edge. Early Pleistocene human fossils are extremely rare in Europe, with no evidence from the UK. The only known species in western Europe of a similar age is Homo antecessor, whose fossil remains have been found at Atapuerca, Spain. The foot sizes and estimated stature of the hominins from Happisburgh fall within the range derived from the fossil evidence of Homo antecessor.
NASA Astrophysics Data System (ADS)
D'Andrea, W. J.; Balascio, N. L.; Bradley, R. S.; Bakke, J.; Gjerde, M.; Kaufman, D. S.; Briner, J. P.; von Gunten, L.
2014-12-01
Generating continuous, accurate and quantitative Holocene temperature estimates from the Arctic is an ongoing challenge. In many Arctic regions, tree ring-based approaches cannot be used and lake sediments provide the most valuable repositories for extracting paleotemperature information. Advances in lacustrine alkenone paleothermometry now allow for quantitative reconstruction of lake-water temperature based on the UK37 values of sedimentary alkenones. In addition, a recent study demonstrated the efficacy of non-destructive scanning reflectance spectroscopy in the visible range (VIS-RS) for high-resolution quantitative temperature reconstruction from arctic lake sediments1. In this presentation, I will report a new UK37-based temperature reconstruction and a scanning VIS-RS record (using the RABD660;670 index as a measure of sedimentary chlorin content) from Kulusuk Lake in southeastern Greenland (65.6°N, 37.1°W). The UK37 record reveals a ~3°C increase in summer lake water temperatures between ~10ka and ~7ka followed by sustained warmth until ~4ka and a gradual (~3°C) cooling until ~400 yr BP. The strong correlation between UK37 and RABD660;670 measured in the same sediment core provides further evidence that in arctic lakes where temperature regulates primary productivity, and thereby sedimentary chlorin content, these proxies can be combined to develop high-resolution quantitative temperature records. The Holocene temperature history of Kulusuk Lake determined using this approach corresponds to changes in the size of the glaciers adjacent to the lake, as inferred from sediment minerogenic properties measured with scanning XRF. Glaciers retreated during early Holocene warming, likely disappeared during the period of mid-Holocene warmth, and advanced after 4ka. I will also discuss new UK37 and RABD660;670 reconstructions from northwestern Svalbard and the central Brooks Range of Alaska within the framework of published regional temperature reconstructions and model simulations of Holocene temperature around the Arctic. 1. von Gunten, L., D'Andrea, W.J., Bradley, R.S. and Huang, Y., 2012, Proxy-to-proxy calibration: Increasing the temporal resolution of quantitative climate reconstructions. Scientific Reports, v. 2, 609. doi: 10:1038/srep00609.
Modelling land-atmosphere interactions in tropical African wetlands
NASA Astrophysics Data System (ADS)
Dadson, S.
2012-04-01
Wetlands interact with the climate system in two ways. First, the availability of water at the land surface introduces important feedbacks on climate via surface fluxes of energy and water [1]. Over wet surfaces, high daytime evaporation rates and suppressed sensible heat fluxes induce a shallower, moister planetary boundary layer, which affects atmospheric instability and favours the initiation of new storms [2]. Second, wetlands form a key link between the hydrological and carbon cycles, via anoxic degradation of organic matter to release methane (CH4). Wetlands are the largest, but least well quantified, single source of CH4, with recent emission estimates ranging from 105-278 Tg yr-1, ~75% of which comes from the tropics [3]. Although the emissions of methane from boreal wetlands and lakes are less than those from tropical wetlands [3], their size and remoteness pose significant challenges to the quantification of their feedbacks to regional and global climate. In this paper, I present a summary of recent work on modelling hydrological and biogeochemical aspects of wetland formation and the associated land-atmosphere feedbacks in African and boreal environments. We have added an overbank inundation model to the Joint UK Land Environment Simulator (JULES). Sub-grid topographic data were used to derive a two-parameter frequency distribution of inundated areas. Our predictions of inundated area are in good agreement with observed estimates of the extent of inundation obtained using satellite infrared and microwave remote sensing [4,5]. The model predicts significant evaporative losses from the inundated region accounting for doubling of the total land-atmosphere water flux during periods of greatest flooding. I also present new parameterisations of methane generation from wetlands. 1. Koster, R.D., et al., 2004, Science, 305(5687): 1138-40. 2. Taylor, C.M., 2010, Geophys. Res. Lett., 37: L05406. 3. US EPA, 2010, Methane and Nitrous Oxide Emissions From Natural Sources, Report EPA 430-R-10-001. 4. S.J. Dadson, et al., 2010, Journal of Geophysical Research, 115, D23114 5. F. Papa, et al., 2010, Journal of Geophysical Research, 115, D12111, doi:10.1029/2009JD012674.
NASA Astrophysics Data System (ADS)
Gommenginger, C.; Foti, G.
2015-12-01
GNSS-Reflectometry (GNSS-R) is a ground breaking ocean remote sensing technique that exploits reflected signals from Global Navigation Satellite Systems (GNSS) to retrieve geophysical information about the ocean surface such as near-surface winds above the ocean. Adopting a bistatic radar configuration, signals emitted by GNSS satellites flying in Medium Earth Orbit (MEO) are received by a GNSS-R receiver on a Low Earth Orbit (LEO) observatory utilizing both a zenith antenna to receive the direct signal from the GNSS and a nadir antenna to acquire the earth-reflected signal. The reflected signal originated from a glistening zone on the ocean surface sited around the Specular Point (SP), the geometrical point on the Earth surface where GNSS signals are forward scattered in the specular direction. The two signals are correlated for different shifts in time (delay) and frequency (Doppler) relative to the specular point (SP) to produce a so-called Delay Doppler Map (DDM) of forward-scattered electromagnetic power over the surface. This paper gives an overview of recent results obtained for wind speed and ocean roughness retrieval with the Low-Earth-Orbiting UK TechDemoSat-1 satellite (TDS-1). Launched in July 2014, TDS-1 provides the first new spaceborne Global Navigation Satellite System-Reflectometry (GNSS-R) data since the pioneering UK-Disaster Monitoring Mission experiment in 2003. We present examples of onboard-processed delay Doppler Maps, including excellent DDM data quality for winds up to 27.9 m/s. The relationship between observed GNSS-R signals, wind speed and ocean roughness is explored using global collocated matchup datasets with METOP ASCAT scatterometer winds and WaveWatch3 numerical wave model output. Several Geophysical Model Functions are proposed, that make it possible to retrieve wind speed without bias and with a precision of the order of 2 m/s even without calibration. This work demonstrates the capabilities of low-cost, low-mass, low-power GNSS-R receivers ahead of their launch on the NASA CYGNSS constellation in 2016.
NASA Astrophysics Data System (ADS)
Sawada, K.; Takeda, M.; Takano, Y.
2014-12-01
The distribution of long-chain (C37 - C39) alkenones in marine sediment has been well documented to record paleo-sea surface temperatures. The alkenones were also found in sediments of terrestrial saline lakes, and recently the calibrations of alkenone unsaturation indices - temperature have been established in continental areas. Furthermore, these biomarkers have been identified in lacustrine sediments on high-latitudinal terrestrial areas such as Greenland and Antarctica. In the present study, the alkenones were identified in the lacustrine sediment cores in freshwater (Lake Naga-ike) and saline lakes (Lake Suribati and Lake Funazoko) on the Skarvsnes, and a saline lake (Lake Skallen Oh-ike) on the Skallen, Antarctica. Here, we report that the alkenone distribution in the Antarctic lakes was examined as paleotemperature proxy. C37-C38 Tetra- and tri-unsaturated alkenones and C37 tetra- and tri-unsaturated alkenoates are identified in all sediment samples. The C37 di-unsaturated (C37:2) alkenones can be identified in sediments of surface layers (0-15 cm) of Lake Naga-ike and layers of 160-190 cm depth, in which age is ca. 3000 years BP by 14C dating, in Lake Skallen Ohike, and alkenone unsaturation index (UK37) is analyzed from these sediments. By using a calibration obtained from a culture strain Chrysotila lamellosa as reported by Nakamura et al. (2014), paleotemperatures are calculated to be 9.2-15ºC in surface sediments of Lake Naga-ike and 6.8-8.6ºC in Lake Skallen Oh-ike, respectively. The estimated temperatures are concordant with summer temperature of lake waters observed in Lake Naga-ike. Also, the highest concentrations of the alkenones and alkenoates are observed in deeper (older) sediment layers from Lake Naga-ikes, which has not been connected the ocean and intruded sea water. This implies that the alkenones are originated from indigenous biological organism(s) in Antarctic lake water. The class distributions (unsaturation ratios) of alkenones varied with core depths in Lake Naga-ike and Lake Suribati, whereas these are nearly constant with core depths in Lake Funazoko. These variations presumably depended on changes of climatic and environmental conditions in lake water. Thus, it is suggested that the alkenone proxies can be applicable for Antarctic climate changes.
NASA Astrophysics Data System (ADS)
Taylor, Robert A.
2010-09-01
These conference proceedings contain the written papers of the contributions presented at Quantum Dot 2010 (QD2010). The conference was held in Nottingham, UK, on 26-30 April 2010. The conference addressed topics in research on: 1. Epitaxial quantum dots (including self-assembled and interface structures, dots defined by electrostatic gates etc): optical properties and electron transport quantum coherence effects spin phenomena optics of dots in cavities interaction with surface plasmons in metal/semiconductor structures opto-electronics applications 2. Novel QD structures: fabrication and physics of graphene dots, dots in nano-wires etc 3. Colloidal quantum dots: growth (shape control and hybrid nanocrystals such as metal/semiconductor, magnetic/semiconductor) assembly and surface functionalisation optical properties and spin dynamics electrical and magnetic properties applications (light emitting devices and solar cells, biological and medical applications, data storage, assemblers) The Editors Acknowledgements Conference Organising Committee: Maurice Skolnick (Chair) Alexander Tartakovskii (Programme Chair) Pavlos Lagoudakis (Programme Chair) Max Migliorato (Conference Secretary) Paola Borri (Publicity) Robert Taylor (Proceedings) Manus Hayne (Treasurer) Ray Murray (Sponsorship) Mohamed Henini (Local Organiser) International Advisory Committee: Yasuhiko Arakawa (Tokyo University, Japan) Manfred Bayer (Dortmund University, Germany) Sergey Gaponenko (Stepanov Institute of Physics, Minsk, Belarus) Pawel Hawrylak (NRC, Ottawa, Canada) Fritz Henneberger (Institute for Physics, Berlin, Germany) Atac Imamoglu (ETH, Zurich, Switzerland) Paul Koenraad (TU Eindhoven, Nethehrlands) Guglielmo Lanzani (Politecnico di Milano, Italy) Jungil Lee (Korea Institute of Science and Technology, Korea) Henri Mariette (CNRS-CEA, Grenoble, France) Lu Jeu Sham (San Diego, USA) Andrew Shields (Toshiba Research Europe, Cambridge, UK) Yoshihisa Yamamoto (Stanford University, USA) Artur Zrenner (Paderborn University, Germany) International Programme Committee: Alexander Eychmüller (TU Dresden, Germany) Jonathan Finley (TU Munich, Germany) Dan Gammon (NRL, Washington, USA) Alexander Govorov (Ohio University, USA) Neil Greenham (Cavendish Laboratory, UK) Vladimir Korenev (Ioffe Institute, Russia) Leo Kouwenhoven (TU Delft, Netherlands) Wolfgang Langbein (Cardiff University, UK) Xavier Marie (CNRS Toulouse, France) David Ritchie (Cambridge, UK) Andrew Sachrajda (IMS, Ottawa, Canada) Katerina Soulantica (University of Toulouse, France) Seigo Tarucha (University of Tokyo, Japan) Carlos Tejedor (UAM, Madrid, Spain) Euijoon Yoon (Seoul National University, Korea) Ulrike Woggon (Tu Berlin, Germany) Proceedings edited and compiled by Profesor Robert A Taylor, University of Oxford
Flooding from Intense Rainfall: an overview of project SINATRA
NASA Astrophysics Data System (ADS)
Cloke, Hannah
2014-05-01
Project SINATRA (Susceptibility of catchments to INTense RAinfall and flooding) is part of the UK NERC's Flooding From Intense Rainfall (FFIR) research programme which aims to reduce the risks of damage and loss of life caused by surface water and flash floods through improved identification, characterisation and prediction of interacting meteorological, hydrological and hydro-morphological processes that contribute to flooding associated with high-intensity rainfall events. Extreme rainfall events may only last for a few hours at most, but can generate terrifying and destructive floods. Their impact can be affected by a wide range factors (or processes) such as the location and intensity of the rainfall, the shape and steepness of the catchment it falls on, how much sediment is moved by the water and the vulnerability of the communities in the flood's path. Furthermore, FFIR are by their nature rapid, making it very difficult for researchers to 'capture' measurements during events. The complexity, speed and lack of field measurements on FFIR make it difficult to create computer models to predict flooding and often we are uncertain as to their accuracy. In addition there is no consensus on how to identify how particular catchments may be vulnerable to FFIR, due to factors such as catchment area, shape, geology and soil type as well as land-use. Additionally, the catchments most susceptible to FFIR are often small and un-gauged. Project SINATRA will: (1) Increase our understanding of what factors cause FFIR and gathering new, high resolution measurements of FFIR by: assembling an archive of past FFIR events in Britain and their impacts, as a prerequisite for improving our ability to predict future occurrences of FFIR; making real time observations of flooding during flood events as well as post-event surveys and historical event reconstruction, using fieldwork and crowd-sourcing methods; and characterizing the physical drivers for UK summer flooding events by identifying the large-scale atmospheric conditions associated with FFIR events, and linking them to catchment type. (2) Use this new understanding and data to improve models of FFIR so we can predict where they may happen nationwide by: employing an integrated catchment/urban scale modelling approach to FFIR at high spatial and temporal scales, modelling rapid catchment response to flash floods and their impacts in urban areas; scaling up to larger catchments by improving the representation of fast riverine and surface water flooding and hydromorphic change (including debris flow) in regional scale models of FFIR; improving the representation of FFIR in the JULES land surface model by integrating river routing and fast runoff processes, and performing assimilation of soil moisture and river discharge into the model run (3) Use these new findings and predictions to provide the Environment Agency and other professionals with information and software they can use to manage FFIR, reducing their damage and impact to communities by: developing tools to enable prediction of future FFIR impacts to support the Flood Forecasting Centre in issuing new 'impacts-based' warnings about their occurrence; developing a FFIR analysis tool to assess risks associated with rare events in complex situations involving incomplete knowledge, analogous to those developed for safety assessment in radioactive waste management.
NASA Astrophysics Data System (ADS)
Hannaford, Jamie; Barker, Lucy; Svensson, Cecilia; Tanguy, Maliko; Laize, Cedric; Bachmair, Sophie; Tijdeman, Erik; Stahl, Kerstin; Collins, Kevin
2016-04-01
Droughts pose a threat to water security in most climate zones and water use sectors. With projections suggesting that droughts will intensify in many parts of the globe, the magnitude of this threat is likely to increase in the future and thus vulnerability of society to drought must be reduced through better preparedness. While the occurrence of drought cannot be prevented in the short term, a number of actions can be taken to reduce vulnerability. Monitoring and early warning (M&EW) systems are often central to drought management strategies aimed at reducing vulnerability, but they are generally less developed than for other hazards. There are many drought indicators available for characterising the hazard but they have only rarely been tested for their ability to capture observed impacts on society or the environment. There is a pressing need to better integrate the physical and social vulnerability elements of drought to improve M&EW systems. The Belmont Forum project DrIVER (Drought Impacts: Vulnerability thresholds in monitoring and Early-warning Research, 2014 - 2016) aims to fill this gap by strengthening the link between natural (hydrometeorological) drought characterisation and ecological and socio-economic impacts on three continents (North America, Europe and Australia). The UK is a key DrIVER case study area. The UK has a well-developed hydrological monitoring programme, but there is currently no national drought focused M&EW system; different actors (water companies, regulators, farmers or industry) typically conduct M&EW for their own particular purposes. In this paper we present the early outcomes of an extensive programme of research designed to provide a scientific foundation for improved M&EW systems for the UK in future. The UK is used here as an example, and the findings could prove useful for other localities seeking to develop M&EW systems. Firstly, we present the results of stakeholder engagement exercises designed to ascertain current use of M&EW and future aspirations. Different stakeholders clearly have different goals for M&EW, but there are a number of common themes, including a desire to better understand the links between the outputs of large-scale M&EW systems (rainfall, river flow, etc), localised triggers used by decision-makers during drought episodes, and actual impacts of drought. Secondly, we present analyses designed to test the utility of a wide range of drought indicators for their use in UK applications. We demonstrate the suitability of standardised indicators (like the SPI) for use in the UK, addressing the suitability of statistical distributions and using these indicators for drought severity quantification and for understanding propagation from meteorological to hydrological drought; all of which are currently poorly understood aspects that are vital for future monitoring. We then address the extent to which these indicators can be used to predict drought impacts, focusing on several sectors (water supply, agriculture and ecosystems). These analyses test which indicators perform best at predicting drought impacts, and seek to identify indicator thresholds that trigger impact occurrence. Unsurprisingly, we found that no single indicator best predicts impacts, and results are domain, sector and season specific. However, we reveal important linkages between indicators and impacts that could enhance the design and delivery of monitoring and forecasting information and its uptake by decision-makers concerned with drought.
Naser, Abu Mohd; Unicomb, Leanne; Doza, Solaiman; Ahmed, Kazi Matin; Rahman, Mahbubur; Uddin, Mohammad Nasir; Quraishi, Shamshad B; Selim, Shahjada; Shamsudduha, Mohammad; Burgess, William; Chang, Howard H; Gribble, Matthew O; Clasen, Thomas F; Luby, Stephen P
2017-01-01
Introduction Saltwater intrusion and salinisation have contributed to drinking water scarcity in many coastal regions globally, leading to dependence on alternative sources for water supply. In southwest coastal Bangladesh, communities have few options but to drink brackish groundwater which has been associated with high blood pressure among the adult population, and pre-eclampsia and gestational hypertension among pregnant women. Managed aquifer recharge (MAR), the purposeful recharge of surface water or rainwater to aquifers to bring hydrological equilibrium, is a potential solution for salinity problem in southwest coastal Bangladesh by creating a freshwater lens within the brackish aquifer. Our study aims to evaluate whether consumption of MAR water improves human health, particularly by reducing blood pressure among communities in coastal Bangladesh. Methods and analysis The study employs a stepped-wedge cluster-randomised controlled community trial design in 16 communities over five monthly visits. During each visit, we will collect data on participants’ source of drinking and cooking water and measure the salinity level and electrical conductivity of household stored water. At each visit, we will also measure the blood pressure of participants ≥20 years of age and pregnant women and collect urine samples for urinary sodium and protein measurements. We will use generalised linear mixed models to determine the association of access to MAR water on blood pressure of the participants. Ethics and dissemination The study protocol has been reviewed and approved by the Institutional Review Boards of the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). Informed written consent will be taken from all the participants. This study is funded by Wellcome Trust, UK. The study findings will be disseminated to the government partners, at research conferences and in peer-reviewed journals. Trial registration number NCT02746003; Pre-results. PMID:28864689
Naser, Abu Mohd; Unicomb, Leanne; Doza, Solaiman; Ahmed, Kazi Matin; Rahman, Mahbubur; Uddin, Mohammad Nasir; Quraishi, Shamshad B; Selim, Shahjada; Shamsudduha, Mohammad; Burgess, William; Chang, Howard H; Gribble, Matthew O; Clasen, Thomas F; Luby, Stephen P
2017-09-01
Saltwater intrusion and salinisation have contributed to drinking water scarcity in many coastal regions globally, leading to dependence on alternative sources for water supply. In southwest coastal Bangladesh, communities have few options but to drink brackish groundwater which has been associated with high blood pressure among the adult population, and pre-eclampsia and gestational hypertension among pregnant women. Managed aquifer recharge (MAR), the purposeful recharge of surface water or rainwater to aquifers to bring hydrological equilibrium, is a potential solution for salinity problem in southwest coastal Bangladesh by creating a freshwater lens within the brackish aquifer. Our study aims to evaluate whether consumption of MAR water improves human health, particularly by reducing blood pressure among communities in coastal Bangladesh. The study employs a stepped-wedge cluster-randomised controlled community trial design in 16 communities over five monthly visits. During each visit, we will collect data on participants' source of drinking and cooking water and measure the salinity level and electrical conductivity of household stored water. At each visit, we will also measure the blood pressure of participants ≥20 years of age and pregnant women and collect urine samples for urinary sodium and protein measurements. We will use generalised linear mixed models to determine the association of access to MAR water on blood pressure of the participants. The study protocol has been reviewed and approved by the Institutional Review Boards of the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). Informed written consent will be taken from all the participants. This study is funded by Wellcome Trust, UK. The study findings will be disseminated to the government partners, at research conferences and in peer-reviewed journals. NCT02746003; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Barber, C M; Wiggans, R E; Carder, M; Agius, R
2017-07-01
To estimate the reported incidence of occupational hypersensitivity pneumonitis (OHP) in the UK and to consider whether the pattern of attributed causation has changed over time. All cases of OHP reported to the SWORD scheme between January 1996 and December 2015 were classified into 1 of 10 categories of the suspected agent. Cases were grouped into four 5-year time periods to examine any changing pattern in incidence or suspected causation. For each time period, the annual incidence was calculated using the estimated number of reported cases and the working population of the UK. Between 1996 and 2015, there were 202 actual cases of OHP reported to SWORD, equating to an estimated 818 cases, when adjusting for the sampling ratio. Over this period, the annual UK incidence was 1.4 per million workers. The mean (SD) age of reported cases was 52 (13) years, and cases were four-times more likely to be men than women. Over the study period, there was a fall in the proportion of cases reported to be due to agricultural exposures (44-12%), and an increase in cases due to metalworking fluids (MWFs, 2-45%). Over the last 20 years, the incidence of OHP in the UK has been ∼1-2 cases per million workers per year. Working with water-based MWFs is now the most commonly suspected causative exposure for OHP cases reported to the SWORD scheme in the UK. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Hyporheic network (Hyporheisches Netzwerk)
NASA Astrophysics Data System (ADS)
Lewandowski, J.; Fleckenstein, J.; Hoehn, E.; Nützmann, G.; Radke, M.; Saenger, N.; Schmidt, C.
2009-04-01
The transition zone between surface waters like streams and rivers and the adjacent aquifers is a zone of paramount ecological importance. Due to the complexity of exchange processes, their temporal variability, and the spatial heterogeneity of the ecotone, the understanding and ability to modell the hydrodynamic, hydrochemical, and (micro-)biological processes is still limited. Therefore, a network of scientists and practitioners involved in research and management of hyporheic zones in German-speaking countries (Germany, Switzerland, Austria) is propsed in analogy to the hyporheic network (www.hyporheic.net) in the UK. The initiators of the network anticipate that an intense scientific exchange of knowledge and methods will improve our understanding of hyporheic processes and in turn our ability to manage them. The network will facilitate the formation of research groups to identify and understand key processes and their interactions. Research will be focused at a few major study sites, to bring together different expertise to allow more detailed, interdisciplinary investigations. Those sites can serve as crystallisation points for new research projects. Exchange within the network will be organized via an internet platform (www.hyporheisches-netzwerk.de), regular workshops, and several working groups dealing with different topics. A fast knowledge transfer is a further aim of the collaboration in order to shorten the time-lag between scientific findings and their implementation into management practice. Water resources management authorities should also be involved in the network to address urgent problems and direct some capacities to answer those questions. For instance, changes in geomorphology, water and temperature regimes as well as other anthropogenic impacts might increase the need for cold water refugia and altered flow regimes to maintain biodiversity. Additional qualitative improvements are required by the EU water framework directive.
Majeed, Haris; Moore, G W K
2018-04-13
It is well known that climate variability and trends have an impact on human morbidity and mortality, especially during the winter. However, there are only a handful of studies that have undertaken quantitative investigations into this impact. We evaluate the association between the UK winter asthma mortality data to a well-established feature of the climate system, the Scandinavian (SCA) pattern. Time series analysis of monthly asthma mortality through the period of January 2001 to December 2015 was conducted, where the data were acquired from the UK's Office for National Statistics. The correlations between indices of important modes of climate variability impacting the UK such as the North Atlantic Oscillation as well as the SCA and the asthma mortality time series were computed. A grid point correlation analysis was also conducted with the asthma data with sea level pressure, surface wind and temperature data acquired from the European Centre for Medium-Range Weather Forecasts. We find that sea level pressure and temperature fluctuations associated with the SCA explain ~20% (>95% CL) of variance in the UK asthma mortality through a period of 2001-2015. Furthermore, the highest winter peak in asthma mortality occurred in the year 2015, during which there were strong northwesterly winds over the UK that were the result of a sea level pressure pattern similar to that associated with the SCA. Our study emphasises the importance of incorporating large-scale geospatial analyses into future research of understanding diseases and its environmental impact on human health. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Ritson, Jonathan P; Bell, Michael; Graham, Nigel J D; Templeton, Michael R; Brazier, Richard E; Verhoef, Anne; Freeman, Chris; Clark, Joanna M
2014-12-15
Uncertainty regarding changes in dissolved organic carbon (DOC) quantity and quality has created interest in managing peatlands for their ecosystem services such as drinking water provision. The evidence base for such interventions is, however, sometimes contradictory. We performed a laboratory climate manipulation using a factorial design on two dominant peatland vegetation types (Calluna vulgaris and Sphagnum Spp.) and a peat soil collected from a drinking water catchment in Exmoor National Park, UK. Temperature and rainfall were set to represent baseline and future conditions under the UKCP09 2080s high emissions scenario for July and August. DOC leachate then underwent standard water treatment of coagulation/flocculation before chlorination. C. vulgaris leached more DOC than Sphagnum Spp. (7.17 versus 3.00 mg g(-1)) with higher specific ultraviolet (SUVA) values and a greater sensitivity to climate, leaching more DOC under simulated future conditions. The peat soil leached less DOC (0.37 mg g(-1)) than the vegetation and was less sensitive to climate. Differences in coagulation removal efficiency between the DOC sources appears to be driven by relative solubilisation of protein-like DOC, observed through the fluorescence peak C/T. Post-coagulation only differences between vegetation types were detected for the regulated disinfection by-products (DBPs), suggesting climate change influence at this scale can be removed via coagulation. Our results suggest current biodiversity restoration programmes to encourage Sphagnum Spp. will result in lower DOC concentrations and SUVA values, particularly with warmer and drier summers. Copyright © 2014 Elsevier Ltd. All rights reserved.
Antarctic subglacial lake exploration: first results and future plans
Siegert, Martin J.; Priscu, John C.; Wadham, Jemma L.; Lyons, W. Berry
2016-01-01
After more than a decade of planning, three attempts were made in 2012–2013 to access, measure in situ properties and directly sample subglacial Antarctic lake environments. First, Russian scientists drilled into the top of Lake Vostok, allowing lake water to infiltrate, and freeze within, the lower part of the ice-core borehole, from which further coring would recover a frozen sample of surface lake water. Second, UK engineers tried unsuccessfully to deploy a clean-access hot-water drill, to sample the water column and sediments of subglacial Lake Ellsworth. Third, a US mission successfully drilled cleanly into subglacial Lake Whillans, a shallow hydraulically active lake at the coastal margin of West Antarctica, obtaining samples that would later be used to prove the existence of microbial life and active biogeochemical cycling beneath the ice sheet. This article summarizes the results of these programmes in terms of the scientific results obtained, the operational knowledge gained and the engineering challenges revealed, to collate what is known about Antarctic subglacial environments and how to explore them in future. While results from Lake Whillans testify to subglacial lakes as being viable biological habitats, the engineering challenges to explore deeper more isolated lakes where unique microorganisms and climate records may be found, as exemplified in the Lake Ellsworth and Vostok missions, are considerable. Through international cooperation, and by using equipment and knowledge of the existing subglacial lake exploration programmes, it is possible that such environments could be explored thoroughly, and at numerous sites, in the near future. PMID:26667917
Antarctic subglacial lake exploration: first results and future plans.
Siegert, Martin J; Priscu, John C; Alekhina, Irina A; Wadham, Jemma L; Lyons, W Berry
2016-01-28
After more than a decade of planning, three attempts were made in 2012-2013 to access, measure in situ properties and directly sample subglacial Antarctic lake environments. First, Russian scientists drilled into the top of Lake Vostok, allowing lake water to infiltrate, and freeze within, the lower part of the ice-core borehole, from which further coring would recover a frozen sample of surface lake water. Second, UK engineers tried unsuccessfully to deploy a clean-access hot-water drill, to sample the water column and sediments of subglacial Lake Ellsworth. Third, a US mission successfully drilled cleanly into subglacial Lake Whillans, a shallow hydraulically active lake at the coastal margin of West Antarctica, obtaining samples that would later be used to prove the existence of microbial life and active biogeochemical cycling beneath the ice sheet. This article summarizes the results of these programmes in terms of the scientific results obtained, the operational knowledge gained and the engineering challenges revealed, to collate what is known about Antarctic subglacial environments and how to explore them in future. While results from Lake Whillans testify to subglacial lakes as being viable biological habitats, the engineering challenges to explore deeper more isolated lakes where unique microorganisms and climate records may be found, as exemplified in the Lake Ellsworth and Vostok missions, are considerable. Through international cooperation, and by using equipment and knowledge of the existing subglacial lake exploration programmes, it is possible that such environments could be explored thoroughly, and at numerous sites, in the near future. © 2015 The Author(s).
Idowu, I A; Alkhaddar, R M; Atherton, W
2014-08-01
Mecoprop-p herbicide is often found in wells and water abstractions in many areas around Europe, the UK inclusive. There is a growing environmental and public health concern about mecoprop-p herbicide pollution in ground and surface water in England. Reviews suggest that extensive work has been carried out on the contribution of mecoprop-p herbicides from agricultural use whilst more work needs to be carried out on the contribution of mecoprop-p herbicide from non-agricultural use. The study covers two landfill sites in Weaver/Gowy Catchment. Mecoprop-p herbicide concentrations in the leachate quality range between 0.06 and 290 microg l1 in cells. High concentration ofmecoprop-p herbicide in the leachate quality suggests that there is a possible source term in the waste stream. This paper addresses the gap by exploring possible source terms of mecoprop-p herbicide contamination on landfill sites and evaluates the impact of public purchase, use and disposal alongside climate change on seasonal variations in mecoprop-p concentrations. Mecoprop-p herbicide was found to exceed the EU drinking water quality standards at the unsaturated zone/aquifer with observed average concentrations ranging between 0.005 and 7.96 microg l1. A route map for mecoprop-p herbicide source term contamination is essential for mitigation and pollution management with emphasis on both consumer and producer responsibility towards use of mecoprop-p product. In addition, improvement in data collection on mecoprop-p concentrations and detailed seasonal herbicide sales for non-agricultural purposes are needed to inform the analysis and decision process.
Delgado, João; Longhurst, Phil; Hickman, Gordon A W; Gauntlett, Daniel M; Howson, Simon F; Irving, Phil; Hart, Alwyn; Pollard, Simon J T
2010-06-15
An enhanced methodology for the policy-level prioritization of intervention options during carcass disposal is presented. Pareto charts provide a semiquantitative analysis of opportunities for multiple exposures to human health, animal health, and the wider environment during carcass disposal; they identify critical control points for risk management and assist in waste technology assessment. Eighty percent of the total availability of more than 1300 potential exposures to human, animal, or environmental receptors is represented by 16 processes, these being dominated by on-farm collection and carcass processing, reinforcing the criticality of effective controls during early stages of animal culling and waste processing. Exposures during mass burials are dominated by ground- and surface-water exposures with noise and odor nuisance prevalent for mass pyres, consistent with U.K. experience. Pareto charts are discussed in the context of other visualization formats for policy officials and promoted as a communication tool for informing the site-specific risk assessments required during the operational phases of exotic disease outbreaks.
Peachey, C J; Sinnett, D; Wilkinson, M; Morgan, G W; Freer-Smith, P H; Hutchings, T R
2009-01-01
In urban areas, a highly variable mixture of pollutants is deposited as particulate matter. The concentration and bioavailability of individual pollutants within particles need to be characterised to ascertain the risks to ecological receptors. This study, carried out at two urban parks, measured the deposition and water-solubility of metals to four species common to UK urban areas. Foliar Cd, Cr, Cu, Fe, Ni, Pb and Zn concentrations were elevated in at least one species compared with those from a rural control site. Concentrations were, however, only affected by distance to road in nettle and, to a lesser extent, birch leaves. Greater concentrations of metal were observed in these species compared to cypress and maple possibly due to differences in plant morphology and leaf surfaces. Solubility appeared to be linked to the size fraction and, therefore, origin of the metal with those present predominantly in the coarse fraction exhibiting low solubility.
Napier, F; Jefferies, C; Heal, K V; Fogg, P; Arcy, B J D; Clarke, R
2009-01-01
SUDS are being increasingly employed to control highway runoff and have the potential to protect groundwater and surface water quality by minimising the risks of both point and diffuse sources of pollution. While these systems are effective at retaining polluted solids by filtration and sedimentation processes, less is known of the detail of pollutant behaviour within SUDS structures. This paper reports on investigations carried out as part of a co-ordinated programme of controlled studies and field measurements at soft-engineered SUDS undertaken in the UK, observing the accumulation and behaviour of traffic-related heavy metals, oil and PAHs. The field data presented were collected from two extended detention basins serving the M74 motorway in the south-west of Scotland. Additional data were supplied from an experimental lysimeter soil core leaching study. Results show that basin design influences pollutant accumulation and behaviour in the basins. Management and/or control strategies are discussed for reducing the impact of traffic-related pollutants on the aqueous environment.
The Narrow Cold-Frontal Rainband of 22/23 November 2013
NASA Technical Reports Server (NTRS)
Kidd, Christopher
2015-01-01
The recent paper in Weather by Young (2014) provided a detailed analysis of an intensive cold front as it passed over the UK on 2223 November 2013. This was an extremely good example of linear convection, as it is described in the paper, or a narrow cold-frontal rainband (NCFR; Hobbs and Biswas, 1979). These features are associated with a low-level jet that lies ahead and parallel to the surface cold front, generating a band of intense but relatively shallow convection (see Koch and Kocin, 1991). Although the structure associated with these systems is not uncommon (e.g. Gatzen, 2011), this case was notable for the (linear) length and the longevity of the feature. Critically, fine-scale radar observations using the 1km, 5min UK composite radar product, produced by the UK Met Office and supplied by the British Atmospheric Data Centre, enabled the timing and progression of the most intense band of this feature tobe examined (see Figure 1).
Rieuwerts, J S; Austin, S; Harris, E A
2009-01-01
The UK is legally required by the EU Water Framework Directive (WFD) to improve the environmental quality of inland and coastal waters in the coming years. Historic metal mine sites are recognised as an important source of some of the elements on the WFD priority chemicals list. Despite their contamination potential, such sites are valued for their heritage and for other cultural and scientific reasons. Remediating historic mining areas to control the contamination of stream waters, whilst also preserving the integrity of the mine site, is a challenge but might be achieved by novel forms of remediation. In this study, we have carried out environmental monitoring at a historic, and culturally-sensitive, lead-silver mine site in southwest England and have undertaken a pilot experiment to investigate the potential for a novel, non-invasive remediation method at the site. Concentrations of Pb and Zn in mine spoil were clearly elevated with geometric mean concentrations of 6,888 and 710 microg g(-1), respectively. Mean concentrations of Pb in stream waters were between 21 and 54 microg l(-1), in exceedance of the WFD environmental quality standard (EQS) of 7.2 microg l(-1) (annual average). Mean Zn concentrations in water were between 30 and 97 microg l(-1), compared to the UK EQS of 66.5 microg l(-1) (average). Stream sediments within, and downstream from, the mining site were similarly elevated, indicating transport of mine waste particles into and within the stream. We undertook a simple trial to investigate the potential of hydroxyapatite, in the form of bonemeal, to passively remove the Pb and Zn, from the stream waters. After percolating through bonemeal in a leaching column, 96-99% of the dissolved Pb and Zn in stream water samples was removed.
New prospects of VESUVIO applied to measurements in water mixtures
NASA Astrophysics Data System (ADS)
Rodríguez Palomino, L. A.; Dawidowski, J.; Blostein, J. J.; Cuello, G. J.
2014-12-01
We present new measurements on mixtures of light and heavy water in the spectrometer VESUVIO (Rutherford Appleton Laboratory, UK), and analyze them from the perspective of different kind of applications. We perform a single detector analysis and show the multiple scattering and attenuation corrections with the aim to employ them in mass- spectrometry. We also show the capabilities to perform transmission measurements to determine total cross sections of an acceptable quality by means of its transmission monitor.
NASA Astrophysics Data System (ADS)
Qassim, Suzane; Dixon, Simon; Rowson, James; Worrall, Fred; Evans, Martin
2013-04-01
Polluted by past atmospheric deposition, eroded and burnt, the Bleaklow plateau (Peak district National Park, UK) has long been degraded. Peatlands are important carbon reservoirs and can act as sources or sinks of carbon. Dissolved organic carbon (DOC) is carbon lost from peatlands via the fluvial pathway and as the major component of water colour it is costly to remove during water treatment processes. The Bleaklow Summit peatlands, were subjected to a large wildfire in 2003 devegetating 5.5km2. This fire prompted stakeholders to initiate a large-scale programme of restoration of the plateau. This study considered restoration techniques across four sites: all four sites were seeded with lawn grass, limed and fertilised; to raise the pH and allow establishment of vegetation. In addition to these interventions, one site also had a mulch of Calluna vulgaris applied to the surface to allow soil stabilisation and promote vegetation establishment and another site had biodegradable geojute textile mesh installed, to stabilize the steep gully surfaces. Another site had a gully block installed, to reduce peat desiccation and erosion. This study will compare the four restored sites to two types of comparators: bare soil sites where no restoration was undertaken and a naturally vegetated site unaffected by the 2003 wildfire. Each site had six replicate dipwells, installed in two groups of three. The depth to the water table was monitored and soil water samples collected for analysis, monthly for 5 years, from Nov 2006 - Jan 2012. No significant difference in DOC concentration was found between control and treated sites. There was, however, a significant difference in DOC composition between sites and over the 5 year period of monitoring. UV-vis absorbance of the samples is used to quantify the fulvic to humic components of DOC. The vegetated control was not significantly different to the bare sites; however the vegetated control had a significantly greater humic fraction of than the seeded, limed and fertilised only site, as well as the seeded, limed, C. vulgaris mulched site. This is possibly related to vegetation and litter layer establishment. A suite of water quality data (conductivity, pH and cation data) are now being analysed in combination with DOC to increase understanding of the relationship between bare site re-vegetation and DOC compositional change.
Tailoring the Surface Properties of Coatings Through Self-Stratification
2016-10-13
34 Biofouling, 26 (8) 961-972 (2010) 16 lguerb, 0, Poleunis, C, Mazeas, F, Compere , C and Bertrand, P, "Antifouling Properties of Poly(methyl methacrylate...technologies. Woodhead Publishing Limited: Cambridge, UK, 2009. 13. lguerb, 0.; Poleunis, C. ; Mazeas, F.; Compere , C. ; Bertrand, P., Antifouling
2012-01-01
Implicit solvation is a mean force approach to model solvent forces acting on a solute molecule. It is frequently used in molecular simulations to reduce the computational cost of solvent treatment. In the first instance, the free energy of solvation and the associated solvent–solute forces can be approximated by a function of the solvent-accessible surface area (SASA) of the solute and differentiated by an atom–specific solvation parameter σiSASA. A procedure for the determination of values for the σiSASA parameters through matching of explicit and implicit solvation forces is proposed. Using the results of Molecular Dynamics simulations of 188 topologically diverse protein structures in water and in implicit solvent, values for the σiSASA parameters for atom types i of the standard amino acids in the GROMOS force field have been determined. A simplified representation based on groups of atom types σgSASA was obtained via partitioning of the atom–type σiSASA distributions by dynamic programming. Three groups of atom types with well separated parameter ranges were obtained, and their performance in implicit versus explicit simulations was assessed. The solvent forces are available at http://mathbio.nimr.mrc.ac.uk/wiki/Solvent_Forces. PMID:23180979
Wave Tank Studies of Strong Modulation of Wind Ripples Due To Long Waves
NASA Astrophysics Data System (ADS)
Ermakov, S.; Sergievskaya, I.; Shchegolkov, Yu.
Modulation of wind capillary-gravity ripples due to long waves has been studied in wave tank experiment at low wind speeds using Ka-band radar. The experiments were carried out both for clean water and the water surface covered with surfactant films. It is obtained that the modulation of radar signals is quite strong and can increase with surfactant concentration and fetch. It is shown that the hydrodynamic Modulation Transfer Function (MTF) calculated for free wind ripples and taking into account the kinematic (straining) effect, variations of the wind stress and variations of surfactant concentration strongly underestimates experimental MTF-values. The effect of strong modulation is assumed to be connected with nonlinear harmonics of longer dm-cm- scale waves - bound waves ("parasitic ripples"). The intensity of bound waves depends strongly on the amplitude of decimetre-scale waves, therefore even weak modulation of the dm-scale waves due to long waves results to strong ("cascade") modulation of bound waves. Modulation of the system of "free/bound waves" is estimated using results of wave tank studies of bound waves generation and is shown to be in quali- tative agreement with experiment. This work was supported by MOD, UK via DERA Winfrith (Project ISTC 1774P) and by RFBR (Project 02-05-65102).
Fluids during diagenesis and sulfate vein formation in sediments at Gale crater, Mars
NASA Astrophysics Data System (ADS)
Schwenzer, S. P.; Bridges, J. C.; Wiens, R. C.; Conrad, P. G.; Kelley, S. P.; Leveille, R.; Mangold, N.; Martín-Torres, J.; McAdam, A.; Newsom, H.; Zorzano, M. P.; Rapin, W.; Spray, J.; Treiman, A. H.; Westall, F.; Fairén, A. G.; Meslin, P.-Y.
2016-11-01
We model the fluids involved in the alteration processes recorded in the Sheepbed Member mudstones of Yellowknife Bay (YKB), Gale crater, Mars, as revealed by the Mars Science Laboratory Curiosity rover investigations. We compare the Gale crater waters with fluids modeled for shergottites, nakhlites, and the ancient meteorite ALH 84001, as well as rocks analyzed by the Mars Exploration rovers, and with terrestrial ground and surface waters. The aqueous solution present during sediment alteration associated with phyllosilicate formation at Gale was high in Na, K, and Si; had low Mg, Fe, and Al concentrations—relative to terrestrial groundwaters such as the Deccan Traps and other modeled Mars fluids; and had near neutral to alkaline pH. Ca and S species were present in the 10-3 to 10-2 concentration range. A fluid local to Gale crater strata produced the alteration products observed by Curiosity and subsequent evaporation of this groundwater-type fluid formed impure sulfate- and silica-rich deposits—veins or horizons. In a second, separate stage of alteration, partial dissolution of this sulfate-rich layer in Yellowknife Bay, or beyond, led to the pure sulfate veins observed in YKB. This scenario is analogous to similar processes identified at a terrestrial site in Triassic sediments with gypsum veins of the Mercia Mudstone Group in Watchet Bay, UK.
NASA Astrophysics Data System (ADS)
Ockenden, Mary C.; Tych, Wlodek; Beven, Keith J.; Collins, Adrian L.; Evans, Robert; Falloon, Peter D.; Forber, Kirsty J.; Hiscock, Kevin M.; Hollaway, Michael J.; Kahana, Ron; Macleod, Christopher J. A.; Villamizar, Martha L.; Wearing, Catherine; Withers, Paul J. A.; Zhou, Jian G.; Benskin, Clare McW. H.; Burke, Sean; Cooper, Richard J.; Freer, Jim E.; Haygarth, Philip M.
2017-12-01
Excess nutrients in surface waters, such as phosphorus (P) from agriculture, result in poor water quality, with adverse effects on ecological health and costs for remediation. However, understanding and prediction of P transfers in catchments have been limited by inadequate data and over-parameterised models with high uncertainty. We show that, with high temporal resolution data, we are able to identify simple dynamic models that capture the P load dynamics in three contrasting agricultural catchments in the UK. For a flashy catchment, a linear, second-order (two pathways) model for discharge gave high simulation efficiencies for short-term storm sequences and was useful in highlighting uncertainties in out-of-bank flows. A model with non-linear rainfall input was appropriate for predicting seasonal or annual cumulative P loads where antecedent conditions affected the catchment response. For second-order models, the time constant for the fast pathway varied between 2 and 15 h for all three catchments and for both discharge and P, confirming that high temporal resolution data are necessary to capture the dynamic responses in small catchments (10-50 km2). The models led to a better understanding of the dominant nutrient transfer modes, which will be helpful in determining phosphorus transfers following changes in precipitation patterns in the future.
Charlesworth, S M; Bennett, J; Waite, A
2016-08-01
A sustainable means of preventing polluted particulates carried in urban storm water entering rivers, groundwater and lakes is by employing vegetated sustainable drainage system (SUDS) devices, or best management practices to trap or biodegrade them. In the UK, a mixture of grass species is recommended for use in devices such as swales or filter strips. However, there is little evidence in support of the efficiency of the individual grasses or mixtures to deal with such contaminated material. A pot-based pollutant retention study was conducted using processed street dust from central Coventry, UK, as a simulated pollutant to be applied in different quantities to a variety of recommended grasses for vegetated SUDS devices. Analysis was conducted on compost cores, roots and shoots for heavy metals (Cd, Cu, Ni, Pb and Zn). Street dust mainly concentrated in the top compost layer for all grasses with only the finer material migrating down the profile. Analysis of roots indicated little accumulation, with ANOVA statistical tests indicating significant differences in heavy metal concentrations, with less in the compost and more in the shoots. Development of root systems on or near the surface possibly explains increased uptake of heavy metals by some species. Overall Agrostis canina and Poa pratensis showed the greatest accumulations compared to their controls although Agrostis capillaris syn.tenuis and Agrostis stolonifera also demonstrated accumulation potential. On ranking, Agrostis canina and Poa pratensis were highest overall. These rankings will assist in selecting the best grasses to address pollution of the urban environment by contaminated particulates.
Seeing the landscape for the trees: Metrics to guide riparian shade management in river catchments
NASA Astrophysics Data System (ADS)
Johnson, Matthew F.; Wilby, Robert L.
2015-05-01
Rising water temperature (Tw) due to anthropogenic climate change may have serious consequences for river ecosystems. Conservation and/or expansion of riparian shade could counter warming and buy time for ecosystems to adapt. However, sensitivity of river reaches to direct solar radiation is highly heterogeneous in space and time, so benefits of shading are also expected to be site specific. We use a network of high-resolution temperature measurements from two upland rivers in the UK, in conjunction with topographic shade modeling, to assess the relative significance of landscape and riparian shade to the thermal behavior of river reaches. Trees occupy 7% of the study catchments (comparable with the UK national average) yet shade covers 52% of the area and is concentrated along river corridors. Riparian shade is most beneficial for managing Tw at distances 5-20 km downstream from the source of the rivers where discharge is modest, flow is dominated by near-surface hydrological pathways, there is a wide floodplain with little landscape shade, and where cumulative solar exposure times are sufficient to affect Tw. For the rivers studied, we find that approximately 0.5 km of complete shade is necessary to off-set Tw by 1°C during July (the month with peak Tw) at a headwater site; whereas 1.1 km of shade is required 25 km downstream. Further research is needed to assess the integrated effect of future changes in air temperature, sunshine duration, direct solar radiation, and downward diffuse radiation on Tw to help tree planting schemes achieve intended outcomes.
1980-03-01
Ennos, A. E., " Measurement by Laser Photography," National Physical Laboratory, Division of Optical Metrology, Teddington, Middlesex, U.K. 9. Archbold...Field Measurement ," Optics and Laser TechnoloZ, pp. 216 - 219, October 1776. 149 37. Khetan, R. P., and Chiang, F. P., "Strain Analysis by One Beam...AD-AO85 145 NAVAL POSTGRADUATE SCHOOL MONTEREY CA F/G 17/8 SURFACE DISPLACEMENT MEASUREMENTS , STRAIN AND VIBRATIONAL ANALY-ETC(U) MAR GO A B
Receptivity of the Boundary Layer to Vibrations of the Wing Surface
NASA Astrophysics Data System (ADS)
Bernots, Tomass; Ruban, Anatoly; Pryce, David; Laminar Flow Control UK Group Team
2014-11-01
In this work we study generation of Tollmien-Schlichting (T-S) waves in the boundary layer due to elastic vibrations of the wing surface. The flow is investigated based on the asymptotic analysis of the Navier-Stokes equations at large values of the Reynolds number. It is assumed that in the spectrum of the wing vibrations there is a harmonic which comes in resonance with the T-S wave on the lower branch of the stability curve. It was found that the vibrations of the wing surface produce pressure perturbations in the flow outside the boundary layer which can be calculated with the help of the piston theory. As the pressure perturbations penetrate into the boundary layer, a Stokes layer forms on the wing surface which appears to be influenced significantly by the compressibility of the flow, and is incapable of producing the T-S waves. The situation changes when the Stokes layer encounters an roughness; near which the flow is described using the triple-deck theory. The solution of the triple-deck problem can be found in an analytic form. Our main concern is with the flow behaviour downstream of the roughness and, in particular, with the amplitude of the generated Tollmien-Schlichting waves. This research was performed in the Laminar Flow Control Centre (LFC-UK) at Imperial College London. The centre is supported by EPSRC, Airbus UK and EADS Innovation Works.
Land-surface parameter optimisation using data assimilation techniques: the adJULES system V1.0
NASA Astrophysics Data System (ADS)
Raoult, Nina M.; Jupp, Tim E.; Cox, Peter M.; Luke, Catherine M.
2016-08-01
Land-surface models (LSMs) are crucial components of the Earth system models (ESMs) that are used to make coupled climate-carbon cycle projections for the 21st century. The Joint UK Land Environment Simulator (JULES) is the land-surface model used in the climate and weather forecast models of the UK Met Office. JULES is also extensively used offline as a land-surface impacts tool, forced with climatologies into the future. In this study, JULES is automatically differentiated with respect to JULES parameters using commercial software from FastOpt, resulting in an analytical gradient, or adjoint, of the model. Using this adjoint, the adJULES parameter estimation system has been developed to search for locally optimum parameters by calibrating against observations. This paper describes adJULES in a data assimilation framework and demonstrates its ability to improve the model-data fit using eddy-covariance measurements of gross primary production (GPP) and latent heat (LE) fluxes. adJULES also has the ability to calibrate over multiple sites simultaneously. This feature is used to define new optimised parameter values for the five plant functional types (PFTs) in JULES. The optimised PFT-specific parameters improve the performance of JULES at over 85 % of the sites used in the study, at both the calibration and evaluation stages. The new improved parameters for JULES are presented along with the associated uncertainties for each parameter.
Facial burns from exploding microwaved foods: Case series and review.
Bagirathan, Shenbana; Rao, Krishna; Al-Benna, Sammy; O'Boyle, Ciaran P
2016-03-01
Microwave ovens allow for quick and simple cooking. However, the importance of adequate food preparation, prior to microwave cooking, and the consequences of inadequate preparation are not well-known. The authors conducted a retrospective outcome analysis of all patients who sustained facial burns from microwaved foods and were treated at a UK regional burns unit over a six-year period. Patients were identified from clinical records. Eight patients presented following inadequate preparation of either tinned potatoes (n=4) or eggs (n=4). All patients sustained <2% total body surface area facial burns. Mean age was 41 years (range 21-68 years). Six cases (75%) had associated ocular injury. One received amniotic membrane grafts; this individual's vision remains poor twelve months after injury. Rapid dielectric heating of water within foods may produce high steam and vapour pressure gradients and cause explosive decompression [1,5,11]. Consumers may fail to recognise differential heating and simply cook foods for longer if they remain cool on the outer surface. Education on safe use and risks of microwave-cooked foods may help prevent these potentially serious injuries. Microwave ovens have become ubiquitous. The authors recognise the need for improved public awareness of safe microwave cooking. Burns resulting from microwave-cooked foods may have life-changing consequences. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.
(Integrity of pressure components of nuclear power plants)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Merkle, J.G.
1989-11-03
The traveler attended the 15th annual MPA Seminar at the University of Stuttgart and the European Symposium on Elastic-Plastic Fracture Mechanics (EPFM) at Freiburg, FRG. Following the symposium the traveler made visits to the IWM Laboratory in Freiburg, FRG, the GKSS Research Center in Geesthacht, FRG, the Welding Institute in Cambridge, UK, and the Structural Integrity Centre at Risley, Warrington, UK. Principal subjects of discussion during the laboratory visits were the measurement of fracture toughness in the upper transition temperature range and the possibility of cooperative analytical and experimental efforts concerning the effects of biaxial stresses on fracture toughness formore » finite length surface cracks in plates and pressure vessel cylinders.« less
A review of dietary selenium intake and selenium status in Europe and the Middle East.
Stoffaneller, Rita; Morse, Nancy L
2015-02-27
This is a systematic review of existing data on dietary selenium (Se) intake and status for various population groups in Europe (including the United Kingdom (UK)) and the Middle East. It includes English language systematic reviews, meta-analyses, randomised controlled trials, cohort studies, cross-sectional and case-control studies obtained through PUBMED searches from January, 2002, to November, 2014, for European data and from 1990 to November 2014, for Middle Eastern data. Reports were selected if they included data on Se intake and status. The search identified 19 European/UK studies and 15 investigations in the Middle East that reported Se intake and Se concentration in water and/or food and 48 European/UK studies and 44 investigations in the Middle East reporting Se status. Suboptimal Se status was reported to be widespread throughout Europe, the UK and the Middle East, and these results agreed with previous reports highlighting the problem. Eastern European countries had lower Se intake than Western European countries. Middle Eastern studies provided varying results, possibly due to varying food habits and imports in different regions and within differing socioeconomic groups. In conclusion, Se intake and status is suboptimal in European and Middle Eastern countries, with less consistency in the Middle East.
A Review of Dietary Selenium Intake and Selenium Status in Europe and the Middle East
Stoffaneller, Rita; Morse, Nancy L.
2015-01-01
This is a systematic review of existing data on dietary selenium (Se) intake and status for various population groups in Europe (including the United Kingdom (UK)) and the Middle East. It includes English language systematic reviews, meta-analyses, randomised controlled trials, cohort studies, cross-sectional and case-control studies obtained through PUBMED searches from January, 2002, to November, 2014, for European data and from 1990 to November 2014, for Middle Eastern data. Reports were selected if they included data on Se intake and status. The search identified 19 European/UK studies and 15 investigations in the Middle East that reported Se intake and Se concentration in water and/or food and 48 European/UK studies and 44 investigations in the Middle East reporting Se status. Suboptimal Se status was reported to be widespread throughout Europe, the UK and the Middle East, and these results agreed with previous reports highlighting the problem. Eastern European countries had lower Se intake than Western European countries. Middle Eastern studies provided varying results, possibly due to varying food habits and imports in different regions and within differing socioeconomic groups. In conclusion, Se intake and status is suboptimal in European and Middle Eastern countries, with less consistency in the Middle East. PMID:25734564
NASA Astrophysics Data System (ADS)
Buckles, L. K.; Weijers, J. W. H.; Tran, X.-M.; Waldron, S.; Sinninghe Damsté, J. S.
2014-03-01
The application of glycerol dialkyl glycerol tetraether (GDGT)-based palaeoenvironmental proxies, such as the BIT index, TEX86 and the MBT/CBT palaeothermometer, has lately been expanded to lacustrine sediments. Given recent research identifying the production of branched, bacterial GDGTs (brGDGTs) within lakes, it is necessary to ascertain the effect of this lacustrine production on GDGT-based proxies. This study profiles a temperate, monomictic lake (Loch Lomond, UK), analysing labile intact polar GDGT lipids (IPLs) and resilient core GDGT lipids (CLs) in catchment soils, small tributary rivers, lake water and lake sediments. Loch Lomond consists of two basins bisected by the Highland Boundary Fault, resulting in a mesotrophic to oligotrophic gradient from south to north. The north basin is fjord-like, while the south basin is shallow with a lowland catchment. Besides abundant influxes of allochthonous soil and peat-derived (CL) brGDGTs, brGDGTs are produced in a variety of settings in Loch Lomond. Rather than integrating a scattered soil signal, there is some evidence that small rivers may contribute to the brGDGT pool through addition of brGDGTs produced in situ in these streams. 300 days of settling particles and water column profiles of suspended particulate matter (SPM; March and September 2011) reveal brGDGT production throughout the water column, with (IPL and CL) brGDGT distributions varying by basin. In lake sediments, in situ brGDGT production affects the distributions of sedimentary brGDGTs despite high soil and peat-derived organic matter influxes from the catchment. MBT/CBT-derived mean annual air temperature (MAAT) estimates from soil, river and lake sediments vary widely. A strong bias towards higher MAATs in the south and lower MAATs in the north basin further complicates the application of the proxy. These results emphasise that caution must be exercised when applying the MBT/CBT palaeothermometer to individual lakes in which the use of the proxy has not been validated and therefore the factors affecting its application are not well understood. Despite elevated BIT indices, (partly) due to in situ brGDGT production, reliable TEX86 lake surface temperature (LST) estimates were obtained from SPM with BIT indices up to 0.9 but containing abundant crenarchaeol. Lower north basin sediments yielded accurate LST estimates but require further evaluation to properly constrain the application of the TEX86 proxy.
Design of Adaptive Organizations for Effects Based Operations
2009-04-04
8217 Activities. The economic and infrastructure sub-model included nodes for each of the main essential services: water , electricity, sewage, health, and...Data * frack !d Numeric T :Mistil» Track Data 0 Event: String InttrctpUK DJIJ Inttrctptor Id Nunwric : ATI5 Tactsejl Piclurt • KA pan - R
Degradation of metaldehyde in water by nanoparticle catalysts and powdered activated carbon.
Li, Zhuojun; Kim, Jong Kyu; Chaudhari, Vrushali; Mayadevi, Suseeladevi; Campos, Luiza C
2017-07-01
Metaldehyde, an organic pesticide widely used in the UK, has been detected in drinking water in the UK with a low concentration (<1 μg L -1 ) which is still above the European and UK standard requirements. This paper investigates the efficiency of four materials: powdered activated carbon (PAC) and carbon-doped titanium dioxide nanocatalyst with different concentrations of carbon (C-1.5, C-40, and C-80) for metaldehyde removal from aqueous solutions by adsorption and oxidation via photocatalysis. PAC was found to be the most effective material which showed almost over 90% removal. Adsorption data were well fitted to the Langmuir isotherm model, giving a q m (maximum/saturation adsorption capacity) value of 32.258 mg g -1 and a K L (Langmuir constant) value of 2.013 L mg -1 . In terms of kinetic study, adsorption of metaldehyde by PAC fitted well with a pseudo-second-order equation, giving the adsorption rate constant k 2 value of 0.023 g mg -1 min -1 , implying rapid adsorption. The nanocatalysts were much less effective in oxidising metaldehyde than PAC with the same metaldehyde concentration and 0.2 g L -1 loading concentration of materials under UV light; the maximum removal achieved by carbon-doped titanium dioxide (C-1.5) nanocatalyst was around 15% for a 7.5 ppm metaldehyde solution. Graphical abstract ᅟ.
Dynamic and thermodynamic processes driving the January 2014 precipitation record in southern UK
NASA Astrophysics Data System (ADS)
Oueslati, B.; Yiou, P.; Jezequel, A.
2017-12-01
Regional extreme precipitation are projected to intensify as a response to planetary climate change, with important impacts on societies. Understanding and anticipating those events remain a major challenge. In this study, we revisit the mechanisms of winter precipitation record that occurred in southern United Kingdom in January 2014. The physical drivers of this event are analyzed using the water vapor budget. Precipitation changes are decomposed into dynamic contributions, related to changes in atmospheric circulation, and thermodynamic contributions, related to changes in water vapor. We attempt to quantify the relative importance of the two contributions during this event and examine the applicability of Clausius-Clapeyron scaling. This work provides a physical interpretation of the mechanisms associated with Southern UK's wettest event, which is complementary to other studies based on statistical approaches (Schaller et al., 2016, Yiou et al., 2017). The analysis is carried out using the ERA-Interim reanalysis. This is motivated by the horizontal resolution of this dataset. It is then applied to present-day simulations and future projections of CMIP5 models on selected extreme precipitation events in southern UK that are comparable to January 2014 in terms of atmospheric circulation.References:Schaller, N. et al. Human influence on climate in the 2014 southern England winter floods and their impacts, Nature Clim. Change, 2016, 6, 627-634 Yiou, P., et al. A statistical framework for conditional extreme event attribution Advances in Statistical Climatology, Meteorology and Oceanography, 2017, 3, 17-31
2011-04-01
Proceedings, Bristol, UK (2006). 5. M. A. Mentzer, Applied Optics Fundamentals and Device Applications: Nano, MOEMS , and Biotechnology, CRC Taylor...ballistic sensing, flash x-ray cineradiography, digital image correlation, image processing al- gorithms, and applications of MOEMS to nano- and
VOC emission rates over London and South East England obtained by airborne eddy covariance.
Vaughan, Adam R; Lee, James D; Shaw, Marvin D; Misztal, Pawel K; Metzger, Stefan; Vieno, Massimo; Davison, Brian; Karl, Thomas G; Carpenter, Lucy J; Lewis, Alastair C; Purvis, Ruth M; Goldstein, Allen H; Hewitt, C Nicholas
2017-08-24
Volatile organic compounds (VOCs) originate from a variety of sources, and play an intrinsic role in influencing air quality. Some VOCs, including benzene, are carcinogens and so directly affect human health, while others, such as isoprene, are very reactive in the atmosphere and play an important role in the formation of secondary pollutants such as ozone and particles. Here we report spatially-resolved measurements of the surface-to-atmosphere fluxes of VOCs across London and SE England made in 2013 and 2014. High-frequency 3-D wind velocities and VOC volume mixing ratios (made by proton transfer reaction - mass spectrometry) were obtained from a low-flying aircraft and used to calculate fluxes using the technique of eddy covariance. A footprint model was then used to quantify the flux contribution from the ground surface at spatial resolution of 100 m, averaged to 1 km. Measured fluxes of benzene over Greater London showed positive agreement with the UK's National Atmospheric Emissions Inventory, with the highest fluxes originating from central London. Comparison of MTBE and toluene fluxes suggest that petroleum evaporation is an important emission source of toluene in central London. Outside London, increased isoprene emissions were observed over wooded areas, at rates greater than those predicted by a UK regional application of the European Monitoring and Evaluation Programme model (EMEP4UK). This work demonstrates the applicability of the airborne eddy covariance method to the determination of anthropogenic and biogenic VOC fluxes and the possibility of validating emission inventories through measurements.
Hosein, I K; Hill, D W; Tan, T Y; Butchart, E G; Wilson, K; Finlay, G; Burge, S; Ribeiro, C D
2005-10-01
This study reports a two-year programme of attempted eradication of Legionella colonization in the potable water supply of a 1000-bed tertiary care teaching hospital in Wales. There was a simultaneous, point-of-care, sterile-water-only policy for all intensive care units (ICU) and bone marrow and renal transplant units in order to prevent acquisition of nosocomial Legionnaires' disease. The programme was initiated following a case of nosocomial pneumonia caused by Legionella pneumophila serogroup 1-Bellingham-like genotype A on the cardiac ICU. The case occurred 14 days after mitral and aortic valve replacement surgery. Clinical and epidemiological investigations implicated aspiration of hospital potable water as the mechanism of infection. Despite interventions with chlorine dioxide costing over 25000 UK pounds per annum, Legionella has remained persistently present in significant numbers (up to 20000 colony forming units/L) and with little reduction in the number of positive sites. Two further cases of nosocomial disease occurred over the following two-year period; in one case, aspiration of tap water was implicated again, and in the other case, instillation of contaminated water into the right main bronchus via a misplaced nasogastric tube was implicated. These cases arose because of inadvertent non-compliance with the sterile-water-only policy in high-risk locations. Enhanced clinical surveillance over the same two-year period detected no other cases of nosocomial disease. This study suggests that attempts at eradication of Legionella spp. from complex water systems may not be a cost-effective measure for prevention of nosocomial infections, and to the best of our knowledge is the first study from the UK to suggest that the introduction of a sterile-water-only policy for ICUs and other high-risk units may be a more cost-effective approach.
Extreme Events in Urban Streams Leading to Extreme Temperatures in Birmingham, UK
NASA Astrophysics Data System (ADS)
Rangecroft, S.; Croghan, D.; Van Loon, A.; Sadler, J. P.; Hannah, D. M.
2016-12-01
Extreme flows and high water temperature events act as critical stressors on the ecological health of rivers. Urban headwater streams are considered particularly vulnerable to the effects of these extreme events. Despite this, such catchments remain poorly characterised and the effect of differences in land use is rarely quantified, especially in relation to water temperature. Thus a key research gap has emerged in understanding the patterns of water temperature during extreme events within contrasting urban, headwater catchments. We studied the headwaters of two bordering urban catchments of contrasting land use within Birmingham, UK. To characterise response to extreme events, precipitation and flow were analysed for the period of 1970-2016. To analyse the effects of extreme events on water temperature, 10 temperature loggers recording at 15 minute intervals were placed within each catchment covering a range of land use for the period May 2016 - present. During peak over threshold flood events higher average peaks were observed in the less urbanised catchment; however highest maximum flow peaks took place in the more densely urbanised catchment. Very similar average drought durations were observed between the two catchments with average flow drought durations of 27 days in the most urbanised catchment, and 29 in the less urbanised catchment. Flashier water temperature regimes were observed within the more urbanised catchment and increases of up to 5 degrees were apparent within 30 minutes during certain storms at the most upstream sites. Only in the most extreme events did the more densely urban stream appear more susceptible to both extreme high flows and extreme water temperature events, possibly resultant from overland flow emerging as the dominant flow pathway during intense precipitation events. Water temperature surges tended to be highly spatially variable indicating the importance of local land use. During smaller events, water temperature was less changeable and spatially variable, suggesting that overland flow may not the dominant flow pathway in such events. During drought events, the effect of catchment land use on water temperature was less apparent.
Moran, Dominic; Dann, Sabrina
2008-05-01
The European Union Water Framework Directive (WFD) enshrines several economic principles in pursuit of 'good ecological status' for Europe's waters and rationalising water use in society. The implicit principle of maximising the social value from use of a scarce resource is reminiscent of the debate about treating water as an economic good, which has competing uses in society. This paper locates the debate about the economic value of water in the requirements of WFD. Specifically, we consider the implications of national reporting requirements for the economic characterisation report that stress the identification of relative value derived from use. As part of the Scottish contribution to the UK reporting exercise, we use a range of secondary data sources to derive economic values for water on a sector basis. We suggest whether the implications of different water values can be followed through in the WFD.
NASA Astrophysics Data System (ADS)
Reinsch, S.; Emmett, B.; Cosby, J.; Mercado, L. M.; Smart, S.; Glanville, H.; Alberola, M. B.; Clark, D.; Robinson, E.; Jones, D.
2015-12-01
The coupling of C, N and P cycles has rarely been studied through the air- land-water continuum. This is essential if we are to enhance land-atmosphere models to account for N and P limitations. It is also important for developing integrated catchment management solutions to deliver improved water quality combined with a wide range of other ecosystem functions and services.We present results from a project which is part of the interdisciplinary pan-UK NERC Macronutrient Cycles Programme (macronutrient-cycles.ouce.ox.ac.uk/). Our aim is to quantify how coupled C, N & P cycles change across a land use intensification gradient from arable to grass, woodland and bog ecosystems and identify the implications for land-atmosphere C exchange. We focus on three key processes; photosynthesis, annual net primary productivity (ANPP) and decomposition and explore their consequences for biodiversity. Other aspects of the project track delivery to, and transformations within, the freshwater and coastal systems. When we explore relationships between C, N and P, results indicate all habitat types fall on a single land use intensification gradient. Stoichiometry suggests plant productivity is primarily N limited. P limitation occurs rarely but at all levels of intensification. Soil priming shows our soils are primarily C limited and, surprisingly, soil acidity provides one of the most powerful single predictors of processes and ecosystem services perhaps as it is a good integrator of many soil properties. Incorporating this knowledge into the UK land-atmosphere model JULES will be used to improve ANPP projections. These will then be used as inputs into a plant species model called MULTIMOVE to enable future scenarios of climate change, land use and air pollution on habitat suitability for > 1400 plant species to be explored. The enhanced Jules model will ensure both N and P limitations on C fluxes from above and below-ground are incorporated into future UK scenario applications.
NASA Astrophysics Data System (ADS)
Reinsch, Sabine; Glanville, Helen; Smart, Simon; Jones, Davey; Mercado, Lina; Blanes-Alberola, Mamen; Cosby, Jack; Emmett, Bridget
2016-04-01
The coupling of C, N and P cycles has rarely been studied through the air- land-water continuum. This is essential if we are to enhance land-atmosphere models to account for N and P limitations. It is also important for developing integrated catchment management solutions to deliver improved water quality combined with a wide range of other ecosystem functions and services. We present results from a project which is part of the interdisciplinary pan-UK NERC Macronutrient Cycles Programme (macronutrient-cycles.ouce.ox.ac.uk/). Our aim is to quantify how coupled C, N & P cycles change across a land use intensification gradient from arable to grass, woodland and bog ecosystems and identify the implications for land-atmosphere C exchange. We focus on three key processes; photosynthesis, annual net primary productivity and decomposition and explore their consequences for biodiversity. Other aspects of the project track delivery to, and transformations within, the freshwater and coastal systems. When we explore relationships between C, N and P, results indicate all habitat types fall on a single land use intensification gradient. Stoichiometry suggests plant productivity is primarily N limited. P limitation occurs rarely but at all levels of intensification. Soil priming shows our soils are primarily C limited and, surprisingly, soil acidity provides one of the most powerful single predictors of processes and ecosystem services perhaps as it is a good integrator of many soil properties. Incorporating this knowledge into the UK land-atmosphere model JULES will improve aNPP projections. These are then being used as inputs into a plant species model called MULTIMOVE to enable future scenarios of climate change, land use and air pollution on habitat suitability for > 1400 plant species to be explored. The enhanced Jules model will ensure both N and P limitations on C fluxes from above and below-ground are incorporated into future UK scenario applications.
Prescribed fire and its impacts on ecosystem services in the UK.
Harper, Ashleigh R; Doerr, Stefan H; Santin, Cristina; Froyd, Cynthia A; Sinnadurai, Paul
2018-05-15
The impacts of vegetation fires on ecosystems are complex and varied affecting a range of important ecosystem services. Fire has the potential to affect the physicochemical and ecological status of water systems, alter several aspects of the carbon cycle (e.g. above- and below-ground carbon storage) and trigger changes in vegetation type and structure. Globally, fire is an essential part of land management in fire-prone regions in, e.g. Australia, the USA and some Mediterranean countries to mitigate the likelihood of catastrophic wildfires and sustain healthy ecosystems. In the less-fire prone UK, fire has a long history of usage in management for enhancing the productivity of heather, red grouse and sheep. This distinctly different socioeconomic tradition of burning underlies some of the controversy in recent decades in the UK around the use of fire. Negative public opinion and opposition from popular media have highlighted concerns around the detrimental impacts burning can have on the health and diversity of upland habitats. It is evident there are many gaps in the current knowledge around the environmental impacts of prescribed burning in less fire-prone regions (e.g. UK). Land owners and managers require a greater level of certainty on the advantages and disadvantages of prescribed burning in comparison to other techniques to better inform management practices. This paper addresses this gap by providing a critical review of published work and future research directions related to the impacts of prescribed fire on three key aspects of ecosystem services: (i) water quality, (ii) carbon dynamics and (iii) habitat composition and structure (biodiversity). Its overall aims are to provide guidance based on the current state-of-the-art for researchers, land owners, managers and policy makers on the potential effects of the use of burning and to inform the wider debate about the place of fire in modern conservation and land management in humid temperate ecosystems. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.
Modelling impacts of temperature, and acidifying and eutrophying deposition on DOC trends
NASA Astrophysics Data System (ADS)
Sawicka, Kasia; Rowe, Ed; Evans, Chris; Monteith, Don; Vanguelova, Elena; Wade, Andrew; Clark, Joanna
2017-04-01
Surface water dissolved organic carbon (DOC) concentrations in large parts of the northern hemisphere have risen over the past three decades, raising concern about enhanced contributions of carbon to the atmosphere and seas and oceans. The effect of declining acid deposition has been identified as a key control on DOC trends in soil and surface waters, since pH and ionic strength affect sorption and desorption of DOC. However, since DOC is derived mainly from recently-fixed carbon, and organic matter decomposition rates are considered sensitive to temperature, uncertainty persists regarding the extent to the relative importance of different drivers that affect these upward trends. We ran the dynamic model MADOC (Model of Acidity and Soil Organic Carbon) for a range of UK soils (podzols, gleysols and peatland), for which the time-series were available, to consider the likely relative importance of decreased deposition of sulphate and chloride, accumulation of reactive N, and higher temperatures, on DOC production in different soils. Modelled patterns of DOC change generally agreed favourably with measurements collated over 10-20 years, but differed markedly between sites. While the acidifying effect of sulphur deposition appeared to be the predominant control on the observed soil water DOC trends in all the soils considered other than a blanket peat, the model suggested that over the long term, the effects of nitrogen deposition on N-limited soils may have been sufficient to elevate the DOC recovery trajectory significantly. The second most influential cause of rising DOC in the model simulations was N deposition in ecosystems that are N-limited and respond with stimulated plant growth. Although non-marine chloride deposition made some contribution to acidification and recovery, it was not amongst the main drivers of DOC change. Warming had almost no effect on modelled historic DOC trends, but may prove to be a significant driver of DOC in future via its influence on nutrient availability and productivity. This suggests that current and future DOC concentrations could also exceed preindustrial levels due to the increased productivity of N enriched ecosystems, having important implications for drinking water catchment management and the setting and pursuit of appropriate restoration targets.
Macronutrient status of UK groundwater: Nitrogen, phosphorus and organic carbon.
Stuart, M E; Lapworth, D J
2016-12-01
Groundwater is a large, slowly changing pool of the macronutrients nitrogen (N), phosphorus (P) and dissolved organic carbon (DOC), with impacts on receptors, surface waters, dependent wetlands and coastal marine ecosystems. Sources of N to groundwater include fertilisers, animal wastes and septic effluents. N species are well-quantified in groundwater and NO 3 -N has a wide range of median values (0-12mg/L). The highest concentrations are in the Chalk of East Anglia and Humberside and the Permo-Triassic Sandstone (PTS) of Staffordshire. The highest concentrations of NH 4 -N are found in confined aquifers. N concentrations have increased with time peaking during the 1980s. Changes in practice have led to the reduction observed in rapidly-responding aquifers. For the Chalk, where the unsaturated zone is thick, improvements may not be seen for decades. P is less well-characterised in UK groundwater reflecting the lack of historical interest in groundwater P, although it can be significant in some aquifer matrices. Groundwater P concentrations are elevated in sandstone formations compared to other lithology and highest in the PTS of the Midlands and northern England (median values>50μg/L). Overall half of the aquifers studied in the UK have median TDP>50μg/L, with values of up to 100μg/L under some urban areas, such as Manchester and Liverpool as well as the Lee Valley. P concentrations in arable areas are variable (20-100μg/L), whereas under semi-natural conditions they are lower (20-50μg/L). There is little information on P trends in groundwater. Most DOC is derived from soils, playing an important part in redox processes. The aquifer matrix can contain high OC and contribute significantly to groundwater DOC. Median values range between 0.4 and 9mg/L, but rarely exceed 5mg/L, except in the Chalk of Yorkshire and Humberside and PTS of Liverpool which have long legacies of anthropogenic pollution. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.
Teaching of direct posterior resin composite restorations in UK dental therapy training programmes.
Lynch, C D; Wilson, N H F
2010-05-08
With the numbers of dental therapists involved in the delivery of dental care within the UK on the increase, and the trend towards the use of direct resin composites (composites) for the restoration of posterior teeth, this study was undertaken to describe the teaching of posterior composites in dental therapy training programmes in the UK. A secondary aim was to identify differences in techniques for posterior composites taught within these dental therapy training programmes. In 2008/9, a questionnaire seeking information on the teaching of posterior composites was distributed by email to 13 centres with dental therapy training programmes in the UK. This questionnaire sought information relating to the teaching of direct posterior composites to dental therapy students, including the amounts of preclinical and clinical teaching in respect of deciduous and permanent teeth, numbers of restorations placed, contraindications to placement, and details in respect of operative techniques. Ten completed responses were received (response rate = 77%). In ten programmes, student dental therapists received clinical training in the placement of composite restorations in the occlusal surfaces of premolar and permanent molar teeth, and nine programmes included such training for two and three surface occlusoproximal restorations. The mean proportions of posterior restorations placed clinically by the trainee dental therapists in permanent teeth using dental amalgam and composite were 52% and 46% respectively (range: amalgam = 20-95%; composite = 5-70%). With the exception of one programme, the teaching of posterior composites is a well established element of dental therapy training. Some variations were noted in the teaching of clinical techniques between respondent training centres. It is suggested that to ensure harmony in approaches to treatments provided by graduated therapists that training centres look to relevant consensus documents, such as those of the British Association for the Teaching of Conservative Dentistry. The findings of our study are important for the future provision of oral healthcare, given the growing evidence base in favour of minimally invasive dentistry.
The UKC2 regional coupled environmental prediction system
NASA Astrophysics Data System (ADS)
Lewis, Huw W.; Castillo Sanchez, Juan Manuel; Graham, Jennifer; Saulter, Andrew; Bornemann, Jorge; Arnold, Alex; Fallmann, Joachim; Harris, Chris; Pearson, David; Ramsdale, Steven; Martínez-de la Torre, Alberto; Bricheno, Lucy; Blyth, Eleanor; Bell, Victoria A.; Davies, Helen; Marthews, Toby R.; O'Neill, Clare; Rumbold, Heather; O'Dea, Enda; Brereton, Ashley; Guihou, Karen; Hines, Adrian; Butenschon, Momme; Dadson, Simon J.; Palmer, Tamzin; Holt, Jason; Reynard, Nick; Best, Martin; Edwards, John; Siddorn, John
2018-01-01
It is hypothesized that more accurate prediction and warning of natural hazards, such as of the impacts of severe weather mediated through various components of the environment, require a more integrated Earth System approach to forecasting. This hypothesis can be explored using regional coupled prediction systems, in which the known interactions and feedbacks between different physical and biogeochemical components of the environment across sky, sea and land can be simulated. Such systems are becoming increasingly common research tools. This paper describes the development of the UKC2 regional coupled research system, which has been delivered under the UK Environmental Prediction Prototype project. This provides the first implementation of an atmosphere-land-ocean-wave modelling system focussed on the United Kingdom and surrounding seas at km-scale resolution. The UKC2 coupled system incorporates models of the atmosphere (Met Office Unified Model), land surface with river routing (JULES), shelf-sea ocean (NEMO) and ocean waves (WAVEWATCH III). These components are coupled, via OASIS3-MCT libraries, at unprecedentedly high resolution across the UK within a north-western European regional domain. A research framework has been established to explore the representation of feedback processes in coupled and uncoupled modes, providing a new research tool for UK environmental science. This paper documents the technical design and implementation of UKC2, along with the associated evaluation framework. An analysis of new results comparing the output of the coupled UKC2 system with relevant forced control simulations for six contrasting case studies of 5-day duration is presented. Results demonstrate that performance can be achieved with the UKC2 system that is at least comparable to its component control simulations. For some cases, improvements in air temperature, sea surface temperature, wind speed, significant wave height and mean wave period highlight the potential benefits of coupling between environmental model components. Results also illustrate that the coupling itself is not sufficient to address all known model issues. Priorities for future development of the UK Environmental Prediction framework and component systems are discussed.
NASA Astrophysics Data System (ADS)
Ritson, Jonathan; Graham, Nigel; Templeton, Michael; Freeman, Christopher; Clark, Joanna
2015-04-01
Organic rich peat soils are a major store of carbon worldwide. Their existence is predicated on high year-round water tables which create an anoxic environment, thus limiting decay, and also to the recalcitrance of plant litter (dead plant material) commonly found in peatland areas. Climate change threatens the stability of peat soils by altering the biogeochemical cycles which control plant decay, lowering water tables so that oxic degradation can occur and by changing habitat niches such that less recalcitrant species can thrive in peatlands. One of the major fluxes of carbon from peatlands is through dissolved organic carbon (DOC) in surface waters. As peatland areas in the UK are often used as source waters for drinking water supply this presents a problem to water utilities as DOC must be effectively removed to limit colour, odour and the formation of potentially carcinogenic by-products on disinfection. Changes in catchment vegetation may occur due to climate change, nutrient deposition and changing bioclimatic envelopes. How different peatland vegetation contribute to DOC flux and how this may change in the future is therefore of interest. A six week laboratory simulation was performed on typical peatland litter (Sphagnum spp., Calluna vulgaris, Molinea caerulea, Juncus effusus) and a peat soil collected from Exmoor National Park, UK. The simulation monitored DOC flux from the decaying litter/soil and considered the impact of different drought severities using the 50th, 25th, 10th and 5th percentiles of the mean July/August monthly rainfall for Exmoor. On rewetting following the drought, all sources produced significantly different amounts of DOC (Tukey HSD p<0.05) in the order Molinia>Juncus>Calluna>Sphagnum>peat. The source also had a significant (ANOVA p<0.001) effect on coagulation removal efficiency, a typical method of removing DOC during drinking water treatment, with Juncus DOC proving the easiest to remove whilst Sphagnum DOC was the most difficult. Sphagnum DOC had the lowest ratio of humic-like to protein-like fluorescence, which is indicative of DOC which is poorly removed by coagulation. An interactive effect was noted between DOC source and the drought treatment which was explored further using a one-way ANOVA with a Holm-Šidák correction. This suggested peat will produce significantly more DOC when affected by drought (p=0.010), possibly explained by increased oxygenation engaging the 'enzymatic latch' mechanism. A similar analysis was performed on the interaction between drought and DOC source for the specific UV absorbance at 254nm (SUVA) value (a measure of aromaticity). This suggested that Molinea caerulea produces DOC of significantly (p=0.001) higher aromaticity following periods of drought. Comparisons between drought and DOC source factors suggest the source in more important than climatic conditions of decay which is consistent with our previously published findings. These results have implications for marginal peatlands which may be at risk from increased water table drawdown in the future as climate changes and where Molinea caerulea, typically a fen species, is encroaching on bog communities.
Gras Dowr joins world`s FPSO fleet
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1997-05-05
The Gras Dowr, a floating production, storage, and offloading vessel (FPSD) for Amerada Hess Ltd.`s North Sea Durward and Dauntless fields, is one of the latest additions to the world`s growing FPSO fleet. The Gras Dowr, anchored in about 90 m of water, lies between the Durward (U.K. Block 21/16) and Dauntless (U.K. Block 21/11) fields, about 3.5 km from the subsea wellhead locations. The Gras Dowr`s main functions, according to Bluewater Offshore Production Systems Ltd., are to: receive fluids from well risers; process incoming fluids to separate the fluid into crude, water, and gas; store dry crude oil andmore » maintain the required temperature; treat effluent to allow for water discharge to the sea; compress gas for gas lift as a future option; provide chemical injection skid for process chemical injection; use a part of the produced gas for fuel gas, and flare excess gas; inject treated seawater into the injection wells; house power generation for process and offloading operation and utilities; offload to a tandem moored shuttle tanker including receiving liquid fuel from the same tanker; provide accommodations for operating and maintenance crews; allow helicopters landings and takeoffs; allow handling and storage of goods transported by supply vessels; moor a shuttle tanker; and control the subsea wells.« less
NASA Astrophysics Data System (ADS)
Kuhlbrodt, T.; Jones, C.
2016-02-01
The UK Earth System Model (UKESM) is currently being developed by the UK Met Office and the academic community in the UK. The low-resolution version of UKESM has got a nominal grid cell size of 150 km in the atmosphere (Unified Model [UM], N96) and 1° in the ocean (NEMO, ORCA1). In several preliminary test configurations of UKESM-N96-ORCA1, we find a significant cold bias in the northern hemisphere in comparison with HadGEM2 (N96-ORCA025, i.e. 0.25° resolution in the ocean). The sea surface is too cold by more than 2 K, and up to 6 K, in large parts of the North Atlantic and the northwest Pacific. In addition to the cold bias, the maximum AMOC transport (diagnosed below 500 m depth) decreases in all the configurations, displaying values between 11 and 14 Sv after 50 years run length. Transport at 26°N is even smaller and hence too weak in relation to observed values (approx. 18 Sv). The mixed layer is too deep within the North Atlantic Current and the Kuroshio, but too shallow north of these currents. The cold bias extends to a depth of several hundred metres. In the North Atlantic, it is accompanied by a freshening of up to 1.5 psu, compared to present-day climatology, along the path of the North Atlantic Current. A core problem appears to be the cessation of deep-water formation in the Labrador Sea. Remarkably, using earlier versions of NEMO and the UM, the AMOC is stable at around 16 or 17 Sv in the N96-ORCA1 configuration. We report on various strategies to reduce the cold bias and enhance the AMOC transport. Changing various parameters that affect the vertical mixing in NEMO has no significant effect. Modifying the bathymetry to deepen and widen the channels across the Greenland-Iceland-Scotland sill leads to a short-term improvement in AMOC transport, but only for about ten years. Strikingly, in a configuration with longer time steps for the atmosphere model we find a climate that is even colder, but has got a more vigorous maximum AMOC transport (14 Sv instead of 12 Sv). Conversely, if the isopycnal diffusivity is augmented by a factor of 1.5, we find a warming and an even weaker AMOC transport. This brings us to further strategies to modify the atmosphere-ocean fluxes of heat and freshwater.
NASA Astrophysics Data System (ADS)
Clancy, Sarah; Worrall, Fred; Davies, Richard; Gluyas, Jon
2017-04-01
The potential growth of shale gas developments within Europe has raised concerns of the possibility of spills and leaks from shale gas sites and from liquid transportation via roads and pipelines. Data from a range of sources has been examined to estimate the likelihood of an incident. From the US, the Texas Railroad Commission and the Colorado Oil and Gas Commission have maintained records of the quantity; reasons for the spill; and reported impacts. For the UK, the Environment Agency pollution incident database and transport statistics from the UKs Department for Transport have also been analysed and used as an analogy to determine the likelihood of an incident or spill on the road. Data were used as an analogue to predict the potential number of spills and leaks that might occur at a well site, or in transport operation, under different shale gas development scenarios if fracking was to go forward in the UK. Since 2014 the Colorado Oil and Gas Commission has recorded 3874 spills in the State of Colorado, the majority of these (1941) consisted of produced water, whereas 835 recorded oil spills. Of all the spills recorded 1809 spilt more than 0.79 m3, with 1356 of these leaking outside the berm of the well site, and three sites requiring construction of an emergency pits to contain the spillage. During 2015, there were 53054 active wells; the percentage of produced oil spilt was 0.001%, whilst the percentage of produced water spilt was 0.009%. Data from the Texas Railroad Commission shows the number of reported spills over 0.16 m3 in Texas since 2009 has increased year on year, with 675 reported in 2009 and 1485 in 2015. The greatest loss each year was of crude oil, with 14176 m3 being spilt in 2015, which is equivalent to 0.0089% of the oil produced. Clean-up operations recover some of the lost fluid; however, much is left unrecovered, annually 60% of the crude oil spilt is recovered, 65% of production fluid is recovered, whereas just 30% of liquid gas is recovered. The most common cause of leakage each year is equipment failure; these results highlight the need for good regulation and maintenance onsite. The UK's Institute of Directors suggests several shale gas production scenarios for the UK and how this would influence truck movement. One of their scenarios suggests the development of well pads with 10-wells and 40 laterals (one well pad with 10 well each with 4 laterals). This type of well pad would be projected to use 544,000 m3 of water, which would generate between 11155-31288 truck movements over 20 years, or 6.1-17.1 per day if averaged over 5 years. Dairy farmers in the UK produce 11 million m3 of milk a year, which if the tanker has a capacity of 30 m3, equates to approximately 366667 milk tanker journeys a year. This study assesses the number of road incidents and milk tanker spills and predicts the likelihood of such events for fluids involved in hydraulic fracturing.
NASA Astrophysics Data System (ADS)
Hendriks, D.; Ball, S. M.; Van der Wegen, M.; Verkaik, J.; van Dam, A.
2016-12-01
We present a coupled groundwater-surface water model for the San Francisco Bay and Sacramento Valley that consists of a combination of a spatially-distributed groundwater model (Modflow) based on the USGS Central Valley model(1) and the Flexible Mesh (FM) surface water model of the Bay Area(2). With this coupled groundwater-surface water model, we assessed effects of climate, surface water abstractions and groundwater pumping on surface water and groundwater levels, groundwater-surface water interaction and infiltration/seepage fluxes. Results show that the effect of climate (high flow and low flow) on surface water and groundwater is significant and most prominent in upstream areas. The surface water abstractions cause significant local surface water levels decrease (over 2 m), which may cause inflow of bay water during low flow periods, resulting in salinization of surface water in more upstream areas. Groundwater level drawdown due to surface water withdrawal is moderate and limited to the area of the withdrawals. The groundwater pumping causes large groundwater level drawdowns (up to 0.8 m) and significant changes in seepage/infiltration fluxes in the model. However, the effect on groundwater-surface water exchange is relatively small. The presented model instrument gives a sound first impression of the effects of climate and water abstraction on both surface water and groundwater. The combination of Modflow and Flexible Mesh has potential for modelling of groundwater-surface water exchange in deltaic areas, also in other parts of the world. However, various improvements need to be made in order to make the simulation results useful in practice. In addition, a water quality aspect could be added to assess salinization processes as well as groundwater-surface water aspects of water and soil pollution. (1) http://ca.water.usgs.gov/projects/central-valley/central-valley-hydrologic-model.html (2) www.d3d-baydelta.org
Effects of peatland burning on hydrology, water quality and aquatic ecosystems
NASA Astrophysics Data System (ADS)
Brown, L. E.; Holden, J.; Palmer, S. M.
2009-04-01
Controlled burning is used worldwide for the management of vegetation, yet there is serious concern about the environmental implications of such practices. Across the UK many peatlands are burned to encourage and maintain heather growth. However, detailed evaluations of the costs, benefits and sustainability of burning are hampered by a lack of basic scientific data. This paper will present the outline of a new three year NERC-funded project called EMBER which provides the first co-ordinated evaluation of vegetation burning on peatland hydrological and ecological processes. Case study sites influenced by prescribed burns will be established in internationally important sites in the Peak District and North Pennines, UK. EMBER will increase understanding of the processes linking prescribed peat vegetation fires, hydrology, water quality and stream invertebrate communities in upland peat dominated catchments. Four work packages will aim to: 1) increase understanding of the effects of moorland patch burning on the hydrology and physicochemistry of peat, through examination of changes in soil hydrology and water quality; 2) provide a better understanding of the effects of moorland patch burning on basin runoff quantity and quality, through examination of river flow regimes, suspended sediment concentration and water chemistry; 3) assess the influence of changes in stream hydrology, water quality and sediment fluxes on stream ecosystems through examination of stream invertebrate community biodiversity and fish abundance and 4) gain a more fundamental understanding of some environmental drivers of upland aquatic community response to burning by experimentally manipulating fine sediment flux under controlled conditions using a series of streamside mesocosms. Taken together these packages will provide a holistic patch- to basin-scale evaluation of burning from the perspective of peat hydrology, chemistry, river water quantity and quality, and stream ecosystems, thus providing the balanced knowledge base which is currently lacking for peatlands.
UK Hazard Assessment for a Laki-type Volcanic Eruption
NASA Astrophysics Data System (ADS)
Witham, Claire; Felton, Chris; Daud, Sophie; Aspinall, Willy; Braban, Christine; Loughlin, Sue; Hort, Matthew; Schmidt, Anja; Vieno, Massimo
2014-05-01
Following the impacts of the Eyjafjallajokull eruption in 2010, two types of volcanic eruption have been added to the UK Government's National Risk Register for Civil Emergencies. One of these, a large gas-rich volcanic eruption, was identified as a high impact natural hazard, one of the three highest priority natural hazards faced by the UK. This eruption scenario is typified by the Laki eruption in Iceland in 1783-1784. The Civil Contingency Secretariat (CCS) of the UK's Cabinet Office, responsible for Civil Protection in the UK, has since been working on quantifying the risk and better understanding its potential impacts. This involves cross-cutting work across UK Government departments and the wider scientific community in order to identify the capabilities needed to respond to an effusive eruption, to exercise the response and develop increased resilience where possible. As part of its current work, CCS has been working closely with the UK Met Office and other UK agencies and academics (represented by the co-authors and others) to generate and assess the impacts of a 'reasonable worst case scenario', which can be used for decision making and preparation in advance of an eruption. Information from the literature and the findings of an expert elicitation have been synthesised to determine appropriate eruption source term parameters and associated uncertainties. This scenario is then being used to create a limited ensemble of model simulations of the dispersion and chemical conversion of the emissions of volcanic gases during such an eruption. The UK Met Office's NAME Lagrangian dispersion model and the Centre for Ecology and Hydrology's EMEP4UK Eulerian model are both being used. Modelling outputs will address the likelihood of near-surface concentrations of sulphur and halogen species being above specified health thresholds. Concentrations at aviation relevant altitudes will also be evaluated, as well as the effects of acid deposition of volcanic species on ecosystems. Modelling results from a preliminary study have suggested a risk to both human health and the environment in the UK and across other parts of Europe from harmful levels of sulphate aerosol (as previously recognised from modelling of a Laki-type eruption by Schmidt et al (2011), amongst others), but also sulphur dioxide, which has not received as much attention. The presentation will discuss the UK's national assessment of risk and how the Government works to prepare for newly identified high impact hazards. We will show how this is benefitting from innovative approaches being taken in the research community and more detailed modelling findings will be presented. We will demonstrate that this work is a good example of practical hazard assessment through collaboration of scientists with decision makers. This work also has wider reaching links back to Supersite and observations initiatives such as the FUTUREVOLC project, as improved monitoring of source characteristics will enable the UK to refine its models (both numerical and procedural) for better risk management. "This work is distributed under the Creative Commons Attribution 3.0 Unported License together with an author copyright. This license does not conflict with the regulations of the Crown Copyright."
NASA Astrophysics Data System (ADS)
Sadatzki, Henrik; Sarnthein, Michael; Andersen, Nils
2016-06-01
Upwelling intensity in the South China Sea has changed over glacial-interglacial cycles in response to orbital-scale changes in the East Asian Monsoon. Here, we evaluate new multi-proxy records of two sediment cores from the north-eastern South China Sea to uncover millennial-scale changes in winter monsoon-driven upwelling over glacial Terminations I and II. On the basis of U/Th-based speleothem chronology, we compare these changes with sediment records of summer monsoon-driven upwelling east of South Vietnam. Ocean upwelling is traced by reduced (UK'37-based) temperature and increased nutrient and productivity estimates of sea surface waters (δ13C on planktic foraminifera, accumulation rates of alkenones, chlorins, and total organic carbon). Accordingly, strong winter upwelling occurred north-west of Luzon (Philippines) during late Marine Isotope Stage 6.2, Heinrich (HS) and Greenland stadials (GS) HS-11, GS-26, GS-25, HS-1, and the Younger Dryas. During these stadials, summer upwelling decreased off South Vietnam and sea surface salinity reached a maximum suggesting a drop in monsoon rains, concurrent with speleothem records of aridity in China. In harmony with a stadial-to-interstadial see-saw pattern, winter upwelling off Luzon in turn was weak during interstadials, in particular those of glacial Terminations I and II, when summer upwelling culminated east of South Vietnam. Most likely, this upwelling terminated widespread deep-water stratification, coeval with the deglacial rise in atmospheric CO2. Yet, a synchronous maximum in precipitation fostered estuarine overturning circulation in the South China Sea, in particular as long as the Borneo Strait was closed when sea level dropped below -40 m.
Toward greener dialysis: a case study to illustrate and encourage the salvage of reject water.
Connor, Andrew; Milne, Steve; Owen, Andrew; Boyle, Gerard; Mortimer, Frances; Stevens, Paul
2010-06-01
Climate change is now considered to be a major global public health concern. However, the very provision of health care itself has a significant impact upon the environment. Action must be taken to reduce this impact. Water is a precious and finite natural resource. Vast quantities of high-grade water are required to provide haemodialysis. The reverse osmosis systems used in the purification process reject approximately two-thirds of the water presented to them. Therefore, around 250 litres of 'reject water' result from the production of the dialysate required for one treatment. This good quality reject water is lost-to-drain in the vast majority of centres worldwide. Simple methodologies exist to recycle this water for alternative purposes. We describe here a case study of the only UK renal service we know to have implemented such water-saving methodologies. We outline the benefits in terms of financial and environmental savings.
NASA Astrophysics Data System (ADS)
Rohe, Alexander; Liang, Dongfang
2017-06-01
The 1st International Conference on the Material Point Method for "Modelling Large Deformation and Soil-Water-Structure Interaction" (MPM2017) was held in Delft, The Netherlands on 10-13 January 2017. This is the first conference organised by the Anura3D MPM Research Community, following a series of international workshops and symposia previously held in The Netherlands, UK, Spain and Italy, as part of the European Commission FP7 Marie-Curie project MPM-DREDGE. We are delighted to present seven contributions in this Special Column of the Journal of Hydrodynamics, and take this opportunity to announce that the 2nd conference, MPM2019, will be held in Cambridge, UK in January 2019.
Navigating the Boundaries of Cultural Difference through Participatory Drama
ERIC Educational Resources Information Center
Winston, Joe; Lin, Mei-Chun
2015-01-01
This article presents a summary of a research project conducted in the UK and Taiwan, examining how two groups of primary aged children responded to the same set of drama lessons designed around a traditional Chinese story, "The Water Ghost" (in Chinese, ??). The authors summarise both the story and their research methodology before…
Saw, Valerie P J; Minassian, Darwin; Dart, John K G; Ramsay, Andrew; Henderson, Hugo; Poniatowski, Stefan; Warwick, Ruth M; Cabral, Suzanne
2007-01-01
Background Amniotic membrane transplantation (AMT), as a new tool in the armamentarium of therapies available for ocular surface problems, became widely available in the UK in 1998. This study evaluates the indications for treatment, the surgical procedures used, and the results of a subset of the first AMT cases carried out by the group using this nationally available supply. This user group model provides data which is different from that obtained from uncontrolled case series, or clinical trials, and may be more representative of the outcomes that can be expected when a procedure becomes widely available. Methods The first 233 AMTs, performed by the UK user group, were evaluated by audit and outcomes were assessed at 3 months. Results Of the 233 transplants, there were 126 (54.1%) valid outcome returns: the outcome for persistent epithelial defects was a healed and stable surface in 11/35 (31.4%, 95% CI 16.9 to 49.3); for chemical/thermal injuries, a healed uninflamed eye with clear cornea in 5/18 (27.8%, 95% CI 9.7 to 53.4); for bullous keratopathy a pain‐free, stable surface without bullae in 4/18 (22.2%, 95% CI 6.4 to 47.6); for ocular surface reconstruction, an epithelialised uninflamed conjunctiva without scarring in 12/23 (52.2%, 95% CI 30.6 to 73.2); and for limbal stem cell deficiency, a corneal phenotype in 4/7 (57.1%). The operative technique least associated with failure was use of a bandage contact lens at the end of the procedure (OR 0.19, 95% CI 0.06 to 0.59, p = 0.004). Previous treatment with topical steroids was significantly associated with failure (OR 5.70, 95% CI 1.77 to 18.43, p = 0.004). Conclusion Although the outcome criteria used in this study were stringent, and the follow‐up duration was short, the results of AMT by this user group were generally less favourable than those of previously reported case series. Controlled clinical trials would improve the quality of evidence for use of amniotic membrane in ocular disease. PMID:17314154
NASA Technical Reports Server (NTRS)
Aiken, James; Hooker, Stanford
1997-01-01
Twice a year, the Royal Research Ship (RRS) James Clark Ross (JCR) steams a meridional transect of the atlantic Ocean between Grimsly (UK) and Stanley (Falkland Islands) with a port call in Montevideo (Uruguay), as part of the annual research activities of the British Antarctic Survey (BAS). In September, the JCR sails from the UK, and the following April it makes the return trip. The ship is operated by the BAS for the Natural Environment Research Council (NERC). The Atlantic Meridional Transect (AMT) Program exploits the passage of the JCR from approximately 50 deg. N to 50 deg. S with a primary objective to investigate physical and biological processes, as well as to measure the mesi-to-basin-scale bio-optical properties of the atlantic Ocean. The calibration and validation of remotely sensed observations of ocean colour is an inherent objective of these studies: first, by relating in situ measurements of water leaving radiance to satellite measurement, and second, by measuring the bio-optically active constituents of the water.
Mounce, S R; Shepherd, W; Sailor, G; Shucksmith, J; Saul, A J
2014-01-01
Combined sewer overflows (CSOs) represent a common feature in combined urban drainage systems and are used to discharge excess water to the environment during heavy storms. To better understand the performance of CSOs, the UK water industry has installed a large number of monitoring systems that provide data for these assets. This paper presents research into the prediction of the hydraulic performance of CSOs using artificial neural networks (ANN) as an alternative to hydraulic models. Previous work has explored using an ANN model for the prediction of chamber depth using time series for depth and rain gauge data. Rainfall intensity data that can be provided by rainfall radar devices can be used to improve on this approach. Results are presented using real data from a CSO for a catchment in the North of England, UK. An ANN model trained with the pseudo-inverse rule was shown to be capable of predicting CSO depth with less than 5% error for predictions more than 1 hour ahead for unseen data. Such predictive approaches are important to the future management of combined sewer systems.
Climate change adaptation in regulated water utilities
NASA Astrophysics Data System (ADS)
Vicuna, S.; Melo, O.; Harou, J. J.; Characklis, G. W.; Ricalde, I.
2017-12-01
Concern about climate change impacts on water supply systems has grown in recent years. However, there are still few examples of pro-active interventions (e.g. infrastructure investment or policy changes) meant to address plausible future changes. Deep uncertainty associated with climate impacts, future demands, and regulatory constraints might explain why utility planning in a range of contexts doesn't explicitly consider climate change scenarios and potential adaptive responses. Given the importance of water supplies for economic development and the cost and longevity of many water infrastructure investments, large urban water supply systems could suffer from lack of pro-active climate change adaptation. Water utilities need to balance the potential for high regret stranded assets on the one side, with insufficient supplies leading to potentially severe socio-economic, political and environmental failures on the other, and need to deal with a range of interests and constraints. This work presents initial findings from a project looking at how cities in Chile, the US and the UK are developing regulatory frameworks that incorporate utility planning under uncertainty. Considering for example the city of Santiago, Chile, recent studies have shown that although high scarcity cost scenarios are plausible, pre-emptive investment to guard from possible water supply failures is still remote and not accommodated by current planning practice. A first goal of the project is to compare and contrast regulatory approaches to utility risks considering climate change adaptation measures. Subsequently we plan to develop and propose a custom approach for the city of Santiago based on lessons learned from other contexts. The methodological approach combines institutional assessment of water supply regulatory frameworks with simulation-based decision-making under uncertainty approaches. Here we present initial work comparing the regulatory frameworks in Chile, UK and USA evaluating their ability to incorporate uncertain climate and other changes into long-term infrastructure investment planning. The potential for regulatory and financial adaptive measures is explored in addition to a discussion on evaluating their appropriateness via various modelling-based intervention decision-making approaches.
NASA Astrophysics Data System (ADS)
Loveless, Sian; Bloomfield, John; Ward, Rob; Davey, Ian; Hart, Alwyn
2016-04-01
In the last five years there has been a renewed interest in onshore oil and gas in England as new extraction technologies and continued energy demand have allowed for the development of less accessible resources. Until now, shale gas has received most attention in England although exploration licences have also been granted for coal bed methane and mine gas in addition to more conventional hydrocarbon resources. While there is some interest in underground coal gasification there are currently no licences granted. Potential impacts on groundwater from shale gas operations have been well publicised. Hazards include contamination from spills or leaks of frack-fluids and returned water, at the surface, through leaky wells or via subsurface pathways from the source rock, and the availability of water resources. Groundwater is an important resource in England, providing an average of 31% of water resources in England and Wales, and up to 100% in some areas of south-east England. In its role as the environmental regulator the Environment Agency must manage the risks associated with these hazards, and those associated with other onshore oil and gas activities, so that they are minimised. Here we focus on the groundwater contamination risk from source rocks though subsurface pathways. Despite the abundant literature emerging from the North American continent there remain great uncertainties as to the risk. These uncertainties are amplified when translated to Europe due to significant policy and geological differences. Research from North America indicates that risk is influenced by the exploitation and well completion methods and the geological setting, including: pre-existing fracture and fault networks; stress regime; petrological and rheological properties of the rock between the source and groundwater receptor and the distance between the source and receptors. A joint British Geological Survey/ EA project - iHydrogeology (http://www.bgs.ac.uk/research/groundwater/shaleGas/iHydrogeology.html) - identified key shale units and Principal Aquifers (http://apps.environment-agency.gov.uk/wiyby/117020.aspx) in England and Wales. The BGS GB3D model (Mathers et al., 2014) was used to produce maps of these and the separation distance between aquifer-shale pairs. The latter maps show large variations across the country and even within basins for the aquifer-shale pairs. For example, the separation distance between the Bowland shale and Triassic sandstone aquifer varies between < 200 m to > 1,500 m. However it is not yet clear what constitutes a safe separation distance. Due to the geological variability across England a current project (3DGWV) will address the need to assess risk and uncertainties both conceptually and on a more site-specific scale. The method above will be extended to other onshore hydrocarbons. Conceptual models of these source releases and pathways will be compared in the context of English geology. Another important outcome of the ihydrogeology project was the recognition that the definition of groundwater bodies with respect to the Water Framework Directive might need to be redefined in a UK context, taking into account these new, 3D risks. In addition to this work the BGS and EA are also conducting one of the first comprehensive baseline monitoring studies in potential shale gas areas and a project looking at the impacts of abandoned wells. Reference: Mathers, et al. (2014). GB3D-a framework for the bedrock geology of Great Britain. Geoscience Data Journal, 1(1), 30-42.
The use of an air filtration system in podiatry clinics.
McLarnon, Nichola; Burrow, Gordon; Maclaren, William; Aidoo, Kofi; Hepher, Mike
2003-06-01
A small-scale study was conducted to ascertain the efficiency and effectiveness of an air filtration system for use in podiatry/chiropody clinics (Electromedia Model 35F (A), Clean Air Ltd, Scotland, UK). Three clinics were identified, enabling comparison of data between podiatry clinics in the West of Scotland. The sampling was conducted using a portable Surface Air Sampler (Cherwell Laboratories, Bicester, UK). Samples were taken on two days at three different times before and after installation of the filtration units. The global results of the study indicate the filter has a statistically significant effect on microbial counts, with an average percentage decrease of 65%. This study is the first time, to the authors' knowledge, such a system has been tested within podiatric practice.
Xu, Zhijun; Yang, Xiao; Wei, Qichao; Zhao, Weilong; Cui, Beiliang; Yang, Xiaoning; Sahai, Nita
2018-06-11
Understanding the molecular mechanism of protein adsorption on solids is critical to their applications in materials synthesis and tissue engineering. Though the water phase at the surface/water interface has been recognized as three types: free water in the bulk region, intermediate water phase and surface-bound water layers adjacent to the surface, the roles of the water and surface in determining the protein adsorption are not clearly identified, particularly at the quantitative level. Herein, we provide a methodology involving the combination of microsecond strengthen sampling simulation and force integration to quantitatively characterize the water-induced contribution and the peptide-surface interactions into the adsorption free energy. Using hydroxyapatite and graphene surfaces as examples, we demonstrate how the distinct interfacial features dominate the delicate force balance between these two thermodynamics parameters, leading to surface preference/resistance to peptide adsorption. Specifically, the water layer provides sustained repelling force against peptide adsorption, as indicated by a monotonic increase in the water-induced free energy profile, whereas the contribution to the free energy from the surface effect is thermodynamically favorable, thus acting as the dominant driving force for peptide adsorptions. More importantly, the revealed adsorption mechanism is critically dictated by the distribution of water phase at the solid/water interface, which plays a crucial role in establishing the force balance between the interactions of the peptide with the water layer and the surface. For the HAP surface, the charged peptide exhibits strong binding affinity to the surface, which is ascribed to the controlling contribution of peptide-surface interaction in the intermediate water phase and the surface-bound water layers are observed as the origin of bioresistance of solid surfaces towards the adsorption of charge-neutral peptides. The preferred peptide adsorption on the graphene, however, is dominated by the surface-induced component at the water layers adjacent to the surface. Our results further elucidate that the intermediate water phase significantly shortens the effective range of the surface dispersion force to guide the diffusion of the peptide to the interface, in sharp contrast to the observation in interfacial systems involving the strong water-surface interaction.
NASA Astrophysics Data System (ADS)
Tesouro, M.; Gimeno, L.; Añel, J. A.; de La Torre, L.; Nieto, R.; Ribera, P.; García, R.; Hernández, E.
2003-04-01
The seasonal cycle of the surface temperature in the Northern Atlantic was investigated with the aim of studying interannual variability. To know how seasonal cycle is influenced by main climate modes could be a powerful tool to improve our seasonal prediction abilities. Data consist of daily temperatures at 2 metres taken from the Climate Research Unit (University of East Anglic_UK) (www.cru.uea.ac.uk) corresponding to the region from 90 W to 90 E longitude and from 88.5 N to 21.9 N latitude and for the last 44 years. Daily data were adjusted to the following expression for each year: y=a+b*sin(((2*PI)/d)x+c) The amplitude of the wave and the first inflexion point were used as indicators of the seasonal cycle. Results show a negative correlation between the NAO index and the amplitude over Northern Europe and over Mexico and a positive correlation over Northern United States and Canada. They also show a negative correlation between the NAO index and the first inflexion point over Northern Europe.
Accelerator mass spectrometry of iodine-129 and its applications in natural water systems
NASA Astrophysics Data System (ADS)
Buraglio, Nadia
During recent decades, huge amount of radioactive waste has been dumped into the earth's surface environments. 129I (T1/2 = 15.6 My) is one of the radioactive products that has been produced through a variety of processes, including atomic weapon testing, reprocessing of nuclear fact and nuclear accidents. This thesis describes development of the Accelerator Mass Spectrometry (AMS) ultra-sensitive atom counting technique at Uppsala Tandem Laboratory to measure 129I and discusses investigations of its distribution in the hydrosphere (marine and fresh water) and precipitation. The AMS technique provides a method for measuring long-lived radioactive isotopes in small samples, relative to other conventional techniques, and thus opens a now line of research. The optimization of the AMS system at Uppsala included testing a time of flight detector, evaluation of the most appropriate charge-state, reduction of molecular interference and improvement of the detection limit. Furthermore, development of a chemical procedure for separation of iodine from natural water samples has been accomplished. The second part of the thesis reports investigations of 129I in natural waters and indicates that high concentrations of 129I (3-4 orders of magnitude higher than in the prenuclear era) are found in most of the considered natural waters. Inventory calculations and results of measurements suggest that the major sources of radioactive iodine are the two main European nuclear reprocessing facilities at Sellafield (U.K.) and La Hague (France). This information provides estimates of the transit time and vertical mixing of water masses in the central Arctic Ocean. Results from precipitation, lakes and runoff are used to elucidate mechanisms of transport of 129I from the point sources and its pathways in the hydrological environment. This study also shows the need for continuous monitoring of the 129I level in the hydrosphere and of its future variability.
Movement of Water Through the Chalk Unsaturated zone
NASA Astrophysics Data System (ADS)
Butler, A.; Ireson, A.; Wheater, H.; Mathias, S.; Finch, J.
2006-12-01
Despite many decades study, quantification of water movement through the Chalk unsaturated zone has proved difficult, due to its particular properties. Chalk comprises a fine grained porous matrix intersected by a fracture network. In much of the unsaturated zone, for most of the time, matric potentials remain between -20 and -0.5 m. Thus the matrix is largely saturated by capillary action, and the fractures are largely de-watered. Therefore, debate has often focussed on the importance of the fractures, as compared with the matrix, for the movement of water. Recently, Mathias et al. (J Hydrol., in press) and Brouyère (J Contam Hydrol,82:195-219,2006) have (independently) proposed an Equivalent Continuum Model, ECM, for the Chalk. This assumes that the fractures can be treated as a porous medium and that the fracture and matrix domains can be treated as a single domain i.e. an equivalent continuum. This requires that the fractures and matrix are in pressure equilibrium, and whilst the theoretical basis for this assumption is reasonable, it has not been demonstrated empirically. In addition, Mathias et al. have demonstrated the importance of rainfall attenuation in the near surface weathered and soil zones of the Chalk for attenuating flow. As part of a national research initiative into groundwater dominated catchments, an extensive field monitoring programme has been implemented at two Chalk catchments in Berkshire (UK). This includes comprehensive soil moisture measurements (water content and matric potential), an extensive network of piezometers and observation wells measuring water table response, and the direct measurement of actual evaporation as well as standard meteorological variables, including rainfall. Using the Kosugi (WRR,32:2697-2703,1996) relationships for soil water retention and hydraulic conductivity a methodology for characterising vertical variation in hydraulic properties from competent chalk at depth through weathered rock to surface soil has been developed using data from one of the above catchments. The model was defined by nine parameters, five of which were identified a priori from observed soil moisture characteristic curves at various elevations, the remaining four by calibration of the numerical model to detailed time series datasets. Effects of parameter identifiability were explored using Monte Carlo analysis. Using a performance criterion based on fitting to matric potentials at a range of depths (from 20 cm to 4 m) over a calendar year, the set of acceptable results appears to support the ECM representation and indicates that fractures in the near- surface competent and weathered rock play an important role in the storage and release of groundwater recharge, whereas the rock matrix is crucial for its transmission to a water table tens of metres below. This conclusion has helped to resolve the debate on the respective roles of fractures and matrix in unsaturated water movement in the Chalk. Furthermore, the model simulations indicate that groundwater recharge can occur continually throughout the year. This helps to explain the apparently enhanced groundwater yields calculated during drought conditions compared with results obtained from pumping tests. It also indicates that current recharge models for the Chalk may need to be revised.
NASA Astrophysics Data System (ADS)
Matthiesen, Stephan; Palmer, Paul; Watson, Andrew; Williams, Mathew
2016-04-01
We give an overview over the structure, objectives, and methods of the UK-based Greenhouse Gases Emissions and Feedback Programme. The overarching objective of this research programme is to deliver improved GHG inventories and predictions for the UK, and for the globe at a regional scale. To address this objective, the Programme has developed a comprehensive, multi-year and interlinked measurement and data analysis programme, focussing on the major GHGs carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The Programme integrates three UK research consortia with complementary objectives, focussing on observation and modelling in the atmosphere, the oceans, and the terrestrial biosphere: GAUGE (Greenhouse gAs Uk and Global Emissions) will produce robust estimates of the UK GHG budget, using new and existing atmospheric measurement networks and modelling activities at a range of scales. It integrates inter-calibrated information from ground-based, airborne, ferry-borne, balloon-borne, and space-borne sensors, including new sensor technology. The GREENHOUSE (Generating Regional Emissions Estimates with a Novel Hierarchy of Observations and Upscaled Simulation Experiments) project aims to understand the spatio-temporal patterns of biogenic GHG emissions in the UK's landscape of managed and semi-managed ecosystems. It uses existing UK field data and several targeted new measurement campaigns to build regional GHG inventories and improve the capabilities of land surface models. RAGNARoCC (Radiatively active gases from the North Atlantic Region and Climate Change) is an oceanographic project to investigate the air-sea fluxes of GHGs in the North Atlantic region. Through dedicated research cruises as well as data collection from ships of opportunity, it develops a comprehensive budget of natural and anthropogenic components of the carbon cycle in the North Atlantic and a better understanding of why the air-sea fluxes of CO2 vary regionally, seasonally and multi-annually. Integration activities link these three projects to foster knowledge exchange across different scales, methods and sub-disciplines, both within the Programme and with the wider research community. The three projects are integrated to improve our understanding of greenhouse gases across domains and scales. The observational components lay the foundation of new measurement infrastructure that will deliver beyond the lifetime of this Programme. Through the development of robust methods to reduce uncertainties in GHG emissions estimates, the Programme supports regulatory efforts to monitor emissions trends and the efficacy of reduction strategies.
NASA Astrophysics Data System (ADS)
Freer, Adam; Quinton, John; Surridge, Ben; McNamara, Niall
2014-05-01
Diffuse (non-point) water pollution from agricultural land continues to challenge water quality management, requiring the adoption of new land management practices. The use of constructed agricultural wetlands is one such practice, designed to trap multiple pollutants mobilised by rainfall prior to them reaching receiving water. Through capturing and storing pollutants in bottom sediments, it could be hypothesised that the abundance of nutrients stored in the anoxic conditions commonly found in these zones may lead to pollutant swapping. Under these circumstances, trapped material may undergo biogeochemical cycling to change chemical or physical form and thereby become more problematic or mobile within the environment. Thus, constructed agricultural wetlands designed to mitigate against one form of pollution may in fact offset the created benefits by 'swapping' this pollution into other forms and pathways, such as through release to the atmosphere. Pollutant swapping to the atmosphere has been noted in analogous wetland systems designed to treat municipal and industrial wastewaters, with significant fluxes of CO2, CH4 and N2O being recorded in some cases. However the small size, low level of engineering and variable nutrient/sediment inputs which are features of constructed agricultural wetlands, means that this knowledge is not directly transferable. Therefore, more information is required when assessing whether a wetland's potential to act as hotspot for pollution swapping outweighs its potential to act as a mitigation tool for surface water pollution. Here we present results from an on-going monitoring study at a trial agricultural wetland located in small a mixed-use catchment in Cumbria, UK. Estimates were made of CH4, CO2 and N2O flux from the wetland surface using adapted floating static chambers, which were then directly compared with fluxes from an undisturbed riparian zone. Results indicate that while greenhouse gas flux from the wetland may be significant, the impacts of this may be greatly diminished when considering wetland size in relation to catchment area. As such, this increased understanding will be valuable when considering the implications of rural land use management for water quality improvement. This knowledge could also be applied to further enhancing our knowledge of gas regional/global gas emissions from freshwater systems, which at the moment are poorly constrained.
An ammonia monitor for the water industry
NASA Technical Reports Server (NTRS)
Brokenshire, J. L.; Cumming, C. A.
1995-01-01
Following the emergence of the European Community as a unified trading and economic entity, the various member states are required to follow certain directives governing their social affairs. Many of these directives concern the quality of the air we breathe, and the water that we use for consumption or in industrial processes. In order to comply with these directives a major overhaul of the water industry in the UK was required. For example, in many coastal towns and resorts there has never been any formal sewage treatment since, traditionally, all waste was dumped at sea through outfall pipes. Because this is no longer acceptable, whole new treatment systems are required.
Characteristics of sedimentary structures in coarse-grained alluvial rivers
NASA Astrophysics Data System (ADS)
Ackerley, David; Powell, Mark
2013-04-01
The characteristics of coarse-grained alluvial surfaces have important implications for the estimation of flow resistance, entrainment thresholds and sediment transport rates in gravel-bed rivers. This area of research has, thus, demanded attention from geomorphologists, sedimentologists, and river engineers. The majority of research has focused towards understanding the characteristics and adjustments in surface grain size. Bed stability, however, is not ultimately defined by particle size but how grains are arranged within the bed surface. For example, by the organisation of particles into a variety of grain and form scale sedimentary structures and bedforms (e.g. imbrication; pebble clusters, stone nets, transverse ribs). While it is widely acknowledged sedimentary structuring must be considered within estimates of flow resistance and sediment transport, relatively little is known about the structural properties of water-worked river gravels. As a consequence, we remain woefully ignorant of this important aspect of gravel-bed river sedimentology. The aim of this poster is to present some preliminary results of a study designed to characterise the morphodynamics of sedimentary structures in coarse-grained alluvial rivers and their implications upon entrainment thresholds and sediment transport rates. The poster focuses on investigating the variability in grain and form scale sedimentary structuring across a number of field sites. Representative patches of three gravel bars on the Rivers Wharfe, Manifold and Afon Elan, UK, have been surveyed using a Leica HDS 3000 Terrestrial Laser Scanner. The resultant raw point-cloud data, recorded at a 4mm resolution, has been registered, filtered, and interpolated to produce highly detailed 2½D digital elevation models of gravel-bed surface topography. These surfaces have been analysed using a number of structural parameters including bed elevation probability distribution function statistics (standard deviation, skewness, kurtosis), semivariograms, and inclination indices. This research enhances our understanding of alluvial bed surface structures and lays the foundations for developing a more detailed understanding of their morphodynamics.
NASA Astrophysics Data System (ADS)
Petrick, Benjamin; McClymont, Erin; van der Meer, Marcel; Marret, Fabienne
2015-04-01
The Southeast Atlantic Ocean is an important component of global ocean circulation, as it includes heat and salt transfer into the Atlantic through Agulhas Leakage. Here, we reconstruct sea surface temperatures (SSTs) and sea surface salinity from Ocean Drilling Program (ODP) Site 1087 in the Southeast Atlantic to investigate surface ocean circulation patterns during the late Pleistocene (0-500 ka). The alkenone-derived U37K'index and assemblages of dinoflagellate cysts are used to reconstruct SSTs. The hydrogen isotope composition of the alkenones (δDalkenone) is used to reconstruct changes in sea-surface salinity. The greatest amplitude of SST warming precedes decreases in benthic δ18O and therefore occurs early in the transition from glacials to interglacials. The timing of the early warming is consistent with previously published foraminifera reconstructions from the same site (Caley et al., 2012). However, δDalkenone decreases at the start of interglacials, suggesting that sea surface salinity increased earlier than the deglacial warmings, and indicating that the pattern of Agulhas leakage is more complex than suggested by SST proxies alone. Furthermore, the δDalkenonevalues indicate a strong salinity increases occurred before both MIS 11 and MIS 1, which are both periods where there is evidence of connection between increased Agulhas Leakage and a stronger Atlantic meridional overturning circulation (AMOC). Finally, the ODP site 1087 record shows an overall trend of increasing SSTs and δDalkenone towards the present day, suggesting that Agulhas leakage has strengthened since 500 ka, which may have impacted the intensity of the AMOC. Caley, T., Giraudeau, J., Malaize, B., Rossignol, L., Pierre, C., 2012. Agulhas leakage as a key process in the modes of Quaternary climate changes. Proc. Natl. Acad. Sci. 109, 6835-6839. doi:10.1073/pnas.1115545109
Land-surface parameter optimisation using data assimilation techniques: the adJULES system V1.0
Raoult, Nina M.; Jupp, Tim E.; Cox, Peter M.; ...
2016-08-25
Land-surface models (LSMs) are crucial components of the Earth system models (ESMs) that are used to make coupled climate–carbon cycle projections for the 21st century. The Joint UK Land Environment Simulator (JULES) is the land-surface model used in the climate and weather forecast models of the UK Met Office. JULES is also extensively used offline as a land-surface impacts tool, forced with climatologies into the future. In this study, JULES is automatically differentiated with respect to JULES parameters using commercial software from FastOpt, resulting in an analytical gradient, or adjoint, of the model. Using this adjoint, the adJULES parameter estimationmore » system has been developed to search for locally optimum parameters by calibrating against observations. This paper describes adJULES in a data assimilation framework and demonstrates its ability to improve the model–data fit using eddy-covariance measurements of gross primary production (GPP) and latent heat (LE) fluxes. adJULES also has the ability to calibrate over multiple sites simultaneously. This feature is used to define new optimised parameter values for the five plant functional types (PFTs) in JULES. The optimised PFT-specific parameters improve the performance of JULES at over 85 % of the sites used in the study, at both the calibration and evaluation stages. Furthermore, the new improved parameters for JULES are presented along with the associated uncertainties for each parameter.« less
NASA Astrophysics Data System (ADS)
Petrick, Benjamin F.; McClymont, Erin L.; Marret, Fabienne; van der Meer, Marcel T. J.
2015-09-01
The Southeast Atlantic Ocean is an important component of global ocean circulation, as it includes heat and salt transfer into the Atlantic through the Agulhas leakage as well as the highly productive Benguela upwelling system. Here we reconstruct sea surface temperatures (SSTs) from Ocean Drilling Program (ODP) Site 1087 in the Southeast Atlantic to investigate surface ocean circulation patterns during the late Pleistocene (0-500 ka). The UK'37 index and dinoflagellate cyst assemblages are used to reconstruct SSTs, δDalkenone is used to reconstruct changes in sea surface salinity, and mass accumulation rates of alkenones and chlorine pigments are quantified to detect changing marine export productivity. The greatest amplitude of SST warming precedes decreases in benthic δ18O and therefore occurs early in the transition from glacials to interglacials. The δDalkenone, as a salinity indicator, increases before SSTs, suggesting that the pattern of Agulhas leakage is more complex than suggested by SST proxies. Marine isotope stage (MIS) 10 shows an anomalous pattern: it is marked by a pronounced increase in chlorine concentration, which may be related to enhanced/expanded Benguela upwelling reaching the core site. We find no evidence of an absence of Agulhas leakage throughout the record, suggesting that there is no Agulhas cutoff even during MIS 10. Finally, the ODP Site 1087 record shows an increasing strength of Agulhas leakage towards the present day, which may have impacted the intensity of the Atlantic meridional overturning circulation. As a result, the new analyses from ODP Site 1087 demonstrate a complex interaction between influences of the Benguela upwelling and the Agulhas leakage through the late Pleistocene, which are inferred here to reflect changing circulation patterns in the Southern Ocean and in the atmosphere.
NASA Astrophysics Data System (ADS)
Younger, Paul L.
2000-06-01
Discharges of contaminated groundwater from abandoned deep mines are a major environmental problem in many parts of the world. While process-based models of pollutant generation have been successfully developed for certain surface mines and waste rock piles of relatively simple geometry and limited areal extent, such models are not readily applicable to large systems of laterally extensive, interconnected, abandoned deep mines. As a first approximation for such systems, hydrological and lithological factors, which can reasonably be expected to influence pollutant release, have been assessed by empirically assessing data from 81 abandoned deep coal mine discharges in the UK. These data demonstrate that after flooding of a deep mine is complete and groundwater begins to migrate from the mine voids into surface waters or adjoining aquifers, flushing of the mine voids by fresh recharge results in a gradual improvement in the quality of groundwater (principally manifested as decreasing Fe concentrations and stabilisation of pH around 7). Alternative representations of the flushing process have been examined. While elegant analytical solutions of the advection-dispersion equation can be made to mimic the changes in iron concentration, parameterisation is tendentious in practice. Scrutiny of the UK data suggest that to a first approximation, the duration of the main period of flushing can be predicted to endure around four times as long as the foregoing process of mine flooding. Short- and long-term iron concentrations (i.e. at the start of the main period of flushing and after its completion, respectively) can be estimated from the sulphur content of the worked strata. If strata composition data are unavailable, some indication of pollution potential can be obtained from considerations of the proximity of worked strata to marine beds (which typically have high pyrite contents). The long-term concentrations of iron in a particular discharge can also be approximated on the basis of the proximity of the discharge location to the outcrop of the most closely associated coal seam (MCACS) and, thus, to zones of possible ongoing pyrite oxidation. The practical application of these simple predictive techniques is facilitated by means of a flowchart.
Attenuation characteristics of the fundamental modes that propagate in buried iron water pipes.
Long, R; Lowe, M; Cawley, P
2003-09-01
The attenuation of the fundamental non-torsional modes that propagate down buried iron water pipes has been studied. The mode shapes, mode attenuation due to leakage into the surrounding medium and the scattering of the modes as they interact with pipe joints and fittings have been investigated. In the low frequency region the mode predicted to dominate over significant propagation distances approximates a plane wave in the water within the pipe. The established acoustic technique used to locate leaks in buried iron water pipes assumes that leak noise propagates as a single non-dispersive mode at a velocity related to the low frequency asymptote of this water borne mode. Experiments have been conducted on buried water mains at test sites in the UK to verify the attenuation and velocity dispersion predictions.
Temporal and Spatial Variation of Chemical Water Quality in a Contour Canal.
NASA Astrophysics Data System (ADS)
Swanson, L. A.; Lunn, R. J.
2004-12-01
Chemical water quality is a highly variable aspect of any water body. Historically numerous researchers have investigated the chemical variability of rivers, streams and wetlands, artificial water bodies such as canals have been largely neglected. Canals are typically hydraulically characterised by low flows and a lack of mixing processes. This can potentially lead to significant spatial variability in water chemistry, and as a result many canals in the UK regularly fail water quality targets at specific locations. Recent changes to UK legislation, following the European Water Framework Directive (2000/60/EC), have resulted in canals being subject to achieving `good ecological status'. In the case of canals, what constitutes `good ecological status' is largely unknown and little expertise is available since historically canal management has not been driven by chemical and ecological quality targets. Consequently, there is an urgent need for new research to determine the main factors influencing canal water quality and their ecological status. This research presents results from a study based on a UK contour canal, the Union Canal in central Scotland. The Union Canal typically demonstrates spatially and temporally variable levels of dissolved oxygen (DO) and orthophosphate (PO4-P): simultaneously, seasonal and diel fluctuations of DO and PO4-P are pronounced at a small number of locations. During 1995, minimum levels of DO along the canal length ranged from 9mgl-1 in Edinburgh to as low as 2mgl-1 approximately 20kms away, this then rose again to 8mgl-1 after a further distance of 2km. These acutely low levels of DO are coupled with events of excessive PO4-P up to 0.235mgl-1:10 times greater than those normally found in rivers, causing localised eutrophication and extensive fish kills. To determine the cause of the `hot spots' of poor water quality found on the Union Canal, simultaneous investigations of the hydraulic regime, spatial and temporal water quality variation and the canal's biological status were carried out. Velocity metering in the canal identified extremely low flow rates ~0.15m3s-1. A tracer testing procedure for the canal's low flow conditions was designed and implemented which identified a lack of rapid dispersion processes with D~0.133m3s-1. Water quality sampling consisted of a year-long programme of high frequency temporal and spatial sampling along the canal length. Observations demonstrate significant variability, with widely differing measurements of DO as little as 5m apart. In addition, spot samples of water quality taken from individual incoming field drains showed PO4-P concentrations up to 2mgl-1, with a predominance of nutrient bound clay and silt sediments that ultimately settle on the canal bed. Due to low dispersion rates, residence times for pollutants are long and field drains, in combination with navigational activity, may well be one of the primary causes of raised nutrient levels at some locations. This research has shown that canal water quality is highly spatially and temporally variable; far in excess of the variability normally found in river systems. This is mainly determined by a lack of hydraulic mixing and the presence of small quantities of incoming runoff water of very low quality. Whilst low in volume, incoming sediment from the drains appears to strongly influence the nearby canal water quality. These results have important consequences both for future monitoring strategies of canals and management of their gradual ecological improvement.
Díez, P; Aird, E G A; Sander, T; Gouldstone, C A; Sharpe, P H G; Lee, C D; Lowe, G; Thomas, R A S; Simnor, T; Bownes, P; Bidmead, M; Gandon, L; Eaton, D; Palmer, A L
2017-11-09
A UK multicentre audit to evaluate HDR and PDR brachytherapy has been performed using alanine absolute dosimetry. This is the first national UK audit performing an absolute dose measurement at a clinically relevant distance (20 mm) from the source. It was performed in both INTERLACE (a phase III multicentre trial in cervical cancer) and non-INTERLACE brachytherapy centres treating gynaecological tumours. Forty-seven UK centres (including the National Physical Laboratory) were visited. A simulated line source was generated within each centre's treatment planning system and dwell times calculated to deliver 10 Gy at 20 mm from the midpoint of the central dwell (representative of Point A of the Manchester system). The line source was delivered in a water-equivalent plastic phantom (Barts Solid Water) encased in blocks of PMMA (polymethyl methacrylate) and charge measured with an ion chamber at 3 positions (120° apart, 20 mm from the source). Absorbed dose was then measured with alanine at the same positions and averaged to reduce source positional uncertainties. Charge was also measured at 50 mm from the source (representative of Point B of the Manchester system). Source types included 46 HDR and PDR 192 Ir sources, (7 Flexisource, 24 mHDR-v2, 12 GammaMed HDR Plus, 2 GammaMed PDR Plus, 1 VS2000) and 1 HDR 60 Co source, (Co0.A86). Alanine measurements when compared to the centres' calculated dose showed a mean difference (±SD) of +1.1% (±1.4%) at 20 mm. Differences were also observed between source types and dose calculation algorithm. Ion chamber measurements demonstrated significant discrepancies between the three holes mainly due to positional variation of the source within the catheter (0.4%-4.9% maximum difference between two holes). This comprehensive audit of absolute dose to water from a simulated line source showed all centres could deliver the prescribed dose to within 5% maximum difference between measurement and calculation.
MODFLOW-based coupled surface water routing and groundwater-flow simulation
Hughes, Joseph D.; Langevin, Christian D.; White, Jeremy T.
2015-01-01
In this paper, we present a flexible approach for simulating one- and two-dimensional routing of surface water using a numerical surface water routing (SWR) code implicitly coupled to the groundwater-flow process in MODFLOW. Surface water routing in SWR can be simulated using a diffusive-wave approximation of the Saint-Venant equations and/or a simplified level-pool approach. SWR can account for surface water flow controlled by backwater conditions caused by small water-surface gradients or surface water control structures. A number of typical surface water control structures, such as culverts, weirs, and gates, can be represented, and it is possible to implement operational rules to manage surface water stages and streamflow. The nonlinear system of surface water flow equations formulated in SWR is solved by using Newton methods and direct or iterative solvers. SWR was tested by simulating the (1) Lal axisymmetric overland flow, (2) V-catchment, and (3) modified Pinder-Sauer problems. Simulated results for these problems compare well with other published results and indicate that SWR provides accurate results for surface water-only and coupled surface water/groundwater problems. Results for an application of SWR and MODFLOW to the Snapper Creek area of Miami-Dade County, Florida, USA are also presented and demonstrate the value of coupled surface water and groundwater simulation in managed, low-relief coastal settings.
PREFACE: International Conference on Fundamentals and Applications of HIPIMS
NASA Astrophysics Data System (ADS)
Ehiasarian, Arutiun; Bandorf, Ralf
2012-09-01
Thin film technology and surface engineering are nowadays key components for numerous innovative products like efficient windows, flat screens, sensors or hard coatings used in tool coating and automotive applications, as well as products for everyday life. In line with the demands of surface technology, coating technology is also evolving and improving. The latest major technology jump was the introduction of pulse technology in physical vapor deposition. High power impulse magnetron sputtering is the most recent development of pulse sputtering. After approximately a decade of intense academic investigation and development we observe today a transfer of this new technology towards industrial processes. As well as several international activities the international conference on fundamentals and applications of HIPIMS continues the success story of the HIPIMS days, initiated in 2004 at Sheffield Hallam University, UK. Becoming the only international conference especially dedicated to HIPIMS the HIPIMS conference is a venue for industrial and academic exchange on the latest developments in this fast evolving new technology. As a joint undertaking of Sheffield Hallam University SHU, Network of Competence for Industrial Plasma Surface Technology INPLAS and Fraunhofer Institute for Surface Engineering and Thin Films IST the HIPIMS conference was launched in 2010 in Sheffield, UK. With 120 delegates the impact of the new conference was underlined. The growing importance of HIPIMS technology was connected with a growth by nearly 35% to 160 participants in 2011 at the second HIPIMS conference in Braunschweig, DE. The participants were made up of equal numbers from research and development (university and research institutes) and industry. Being a global conference representatives from 25 different countries from all continents attended. The HIPIMS conference is also in joint collaboration with the COST Action MP0804 Highly Ionized Pulse Plasma Processes (www.hipp-cost.eu). COST (European Cooperation in Science and Technology) is one of the longest-running European frameworks supporting cooperation among scientists and researchers across Europe (www.cost.eu). The COST Action MP0804 HIPP processes focuses on the fundamentals and the industrial implementation of highly ionized pulse plasmas, where HIPIMS is the most prominent and most mature technology, today. Over 50 high level contributions, divided in 37 oral and 14 poster presentations were highly appreciated by the professional audience. The message from 2011 was that HIPIMS technology has now reached industry. In the opening session of the conference representatives from different companies reported on the latest developments in industrialization. Using HIPIMS technology, the lifetime of mills using a state of the art coating can be extended by 50%. Comparable deposition rates for coating cutting inserts on the different faces are reported. The ice-free window for automotive application is one solution just becoming available by HIPIMS technology. The talks from international experts covered a range from fundamental physics, experimental investigations, theoretically modeling to several applications and made the international conference on fundamentals and applications a success story to be continued in the following years. Arutiun Ehiasarian and Ralf Bandorf (Conference Chairmen of HIPIMS 2010 and 2011, respectively) Organising Committee (2010 and 2011) - Affiliations Professor Dr Papken Hovsepian (Sheffield Hallam University, Nanotechnology Center for PVD Research, UK) Professor Dr Günter Bräuer (Fraunhofer Institute for Surface Engineering and Thin Films IST/ Network of Competence INPLAS, Braunschweig, DE) Professor Dr Arutiun P. Ehiasarian (Sheffield Hallam University, Materials Research Institute, UK) Dr Ralf Bandorf (Fraunhofer Institute for Surface Engineering and Thin Films IST, Braunschweig, DE) Main Sponsor Society of Vacuum Coaters SVC Albuquerque, New Mexico, USA Sponsors Ionbond Netherlands BV Venlo, NL Hauzer Techno Coating BV Venlo, NL Hüttinger Elektronik GmbH + Co. KG Freiburg, DE Conference Photos Conference photograph Attendees HIPIMS Conference 2010, Sheffield, UK Conference photograph Attendees HIPIMS Conference 2011, Braunschweig, Germany
Oesterreich, Babett; Lorenz, Birgit; Schmitter, Tim; Kontermann, Roland; Zenn, Michael; Zimmermann, Bastian; Haake, Markus; Lorenz, Udo; Ohlsen, Knut
2014-01-01
Multi-antigen immunotherapy approaches against Staphylococcus aureus are expected to have the best chance of clinical success when used in combinatorial therapy, potentially incorporating opsonic killing of bacteria and toxin neutralization. We recently reported the development of a murine monoclonal antibody specific for the immunodominant staphylococcal antigen A (IsaA), which showed highly efficient staphylococcal killing in experimental infection models of S. aureus. If IsaA-specific antibodies are to be used as a component of combination therapy in humans, the binding specificity and biological activity of the humanized variant must be preserved. Here, we describe the functional characterization of a humanized monoclonal IgG1 variant designated, hUK-66. The humanized antibody showed comparable binding kinetics to those of its murine parent, and recognized the target antigen IsaA on the surface of clinically relevant S. aureus lineages. Furthermore, hUK-66 enhances the killing of S. aureus in whole blood (a physiological environment) samples from healthy subjects and patients prone to staphylococcal infections such as diabetes and dialysis patients, and patients with generalized artery occlusive disease indicating no interference with already present natural antibodies. Taken together, these data indicate that hUK-66 mediates bacterial killing even in high risk patients and thus, could play a role for immunotherapy strategies to combat severe S. aureus infections.
Wetlands inform how climate extremes influence surface water expansion and contraction
NASA Astrophysics Data System (ADS)
Vanderhoof, Melanie K.; Lane, Charles R.; McManus, Michael G.; Alexander, Laurie C.; Christensen, Jay R.
2018-03-01
Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985-2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage. From these findings, we can expect that shifts in precipitation and evaporative demand will have uneven effects on surface water quantity. Accurate predictions regarding the effect of climate change on surface water quantity will require consideration of hydrology-related landscape characteristics including wetland storage and arrangement.
NASA Astrophysics Data System (ADS)
Worrall, F.; Howden, N. J. K.
2016-12-01
We have developed a number of methods to estimate the fate of fluvial organic matter through UK catchments. Here we include dissolved organic matter (DOM), particulate organic matter (POC), and dissolved gases to estimate losses from the terrestrial biosphere; in-stream losses and production (including the role of water and waste treatment); and export to the continental shelf and atmsophere. We use multiple approaches, including: mass balance studies, modelling and experimentation. Mass balance studies suggest that the UK terrestrial biosphere losses 5 Mtonnes C/yr (21.8 tonnes C/km2/yr) in the proportion of 7:22:4 (POC:DOC:diss. CO2). The mass balance studies suggest 3.5 Mtonnes C/yr (15.2 tonnes C/km2/yr) is lost to the atmosphere in the proportion 8:75:17 (POC:DOC:diss. CO2); UK rivers have short residence times (typically 1-2 days) and so the diurnal cycle becomes critical. Experiments show that turnover rates are close to zero overnight but that these can be periods of DOM production from turnover of POM and that the presence of POM may inhibit turnover of DOM; The development and modelling using physically-explicit rate laws showed that the loss of DOC was between 24 and 37% - lower than that estimated from mass balance studies, but that the loss rate of TOC (DOC + POC) was between 57 and 80% - close to that estimated from mass balance studies; The turnover of organic particles within rivers means that any notion that soil erosion leads to net carbon drawdown is entirely negated and the emission factor for gross soil erosion is estimated to be between 0.11 and 0.66 tonnes CO2eq/yr for every 1 tonne of gross erosion; and, Studies of molecular change of DOM and POM along rivers shows that, while POM represents an admixture of its sources (soils and vegetation), the DOM which enters rivers as highly oxidised becomes more reduced in channel. The release of greenhouse gases from UK rivers is now estimated to be between 15,800 - 33,000 ktonnes CO2eq/yr equivalent to between 67 and 131 tonnes CO2eq/km2/yr with fluvial organic matter between 12,328 and 15,922 ktonnes CO2eq/yr in the proportion 5:86:8 - N2O:CO2:CH4. The emissions factor for 1 tonne of organic carbon entering the UK fluvial network has a median value of 3.01 tonnes CO2eq/yr with a 5th to 95th percentile range of 2.60 to 3.59 tonnes CO2eq/yr.
Gonthier, G.J.; Kleiss, B.A.
1996-01-01
The U.S. Geological Survey, working in cooperation with the U.S. Army Corps of Engineers, Waterways Experiment Station, collected surface-water and ground-water data from 119 wells and 13 staff gages from September 1989 to September 1992 to describe ground-water flow patterns and water budget in the Black Swamp, a bottomland forested wetland in eastern Arkansas. The study area was between two streamflow gaging stations located about 30.5 river miles apart on the Cache River. Ground-water flow was from northwest to southeast with some diversion toward the Cache River. Hydraulic connection between the surface water and the alluvial aquifer is indicated by nearly equal changes in surface-water and ground-water levels near the Cache River. Diurnal fluctuations of hydraulic head ranged from more than 0 to 0.38 feet and were caused by evapotranspiration. Changes in hydraulic head of the alluvial aquifer beneath the wetland lagged behind stage fluctuations and created the potential for changes in ground-water movement. Differences between surface-water levels in the wetland and stage of the Cache River created a frequently occurring local ground-water flow condition in which surface water in the wetland seeped into the upper part of the alluvial aquifer and then seeped into the Cache River. When the Cache River flooded the wetland, ground water consistently seeped to the surface during falling surface-water stage and surface water seeped into the ground during rising surface-water stage. Ground-water flow was a minor component of the water budget, accounting for less than 1 percent of both inflow and outflow. Surface-water drainage from the study area through diversion canals was not accounted for in the water budget and may be the reason for a surplus of water in the budget. Even though ground-water flow volume is small compared to other water budget components, ground-water seepage to the wetland surface may still be vital to some wetland functions.
NASA Astrophysics Data System (ADS)
Noacco, V.; Howden, N. J. K.; Wagener, T.; Worrall, F.; Burt, T. P.
2015-12-01
This study investigates drivers of changing dissolved organic carbon (DOC) export in the UK's River Thames basin between 1884 and 2014. Specifically, we consider how the impacts of land-use change and population growth drive increases in DOC concentrations and fluxes at the basin outlet. Such key factors for the long-term increase in riverine DOC in temperate, mineral-soil catchments are still widely debated. First, we estimate soil organic carbon (SOC) stocks in the Thames basin for the period. Second, we convert SOC losses due to land-use change into DOC loss to surface waters through runoff. Finally, we combine this input of DOC with an export coefficient model that considers catchment drivers for DOC release to the river. SOC stocks for each year are calculated from a large database of typical SOC levels for land-uses present in the Thames basin and are combined with literature values of transition times for SOC to adjust to a new level following land-use change. We also account for climate change effects on SOC stock due to temperature increases, which reduces SOC stocks as soil organic matter turnover rates increase. Our work shows that the major driver for DOC increase to the river Thames was the rise in the catchment population, where the increase in urban area was used as a proxy. This highlights the role of sewage effluent in contributing to the rise of fluvial DOC, even though wastewater treatments were in place since the early 1990s. Land-use change had significant but short-term impacts in the increase in DOC, mainly due to massive conversion of permanent grassland into arable land during World War II.
Bussi, Gianbattista; Whitehead, Paul G; Bowes, Michael J; Read, Daniel S; Prudhomme, Christel; Dadson, Simon J
2016-12-01
Potential increases of phytoplankton concentrations in river systems due to global warming and changing climate could pose a serious threat to the anthropogenic use of surface waters. Nevertheless, the extent of the effect of climatic alterations on phytoplankton concentrations in river systems has not yet been analysed in detail. In this study, we assess the impact of a change in precipitation and temperature on river phytoplankton concentration by means of a physically-based model. A scenario-neutral methodology has been employed to evaluate the effects of climate alterations on flow, phosphorus concentration and phytoplankton concentration of the River Thames (southern England). In particular, five groups of phytoplankton are considered, representing a range of size classes and pigment phenotypes, under three different land-use/land-management scenarios to assess their impact on phytoplankton population levels. The model results are evaluated within the framework of future climate projections, using the UK Climate Projections 09 (UKCP09) for the 2030s. The results of the model demonstrate that an increase in average phytoplankton concentration due to climate change is highly likely to occur, with the magnitude varying depending on the location along the River Thames. Cyanobacteria show significant increases under future climate change and land use change. An expansion of intensive agriculture accentuates the growth in phytoplankton, especially in the upper reaches of the River Thames. However, an optimal phosphorus removal mitigation strategy, which combines reduction of fertiliser application and phosphorus removal from wastewater, can help to reduce this increase in phytoplankton concentration, and in some cases, compensate for the effect of rising temperature. Copyright © 2016 Elsevier B.V. All rights reserved.
MODFLOW-Based Coupled Surface Water Routing and Groundwater-Flow Simulation.
Hughes, J D; Langevin, C D; White, J T
2015-01-01
In this paper, we present a flexible approach for simulating one- and two-dimensional routing of surface water using a numerical surface water routing (SWR) code implicitly coupled to the groundwater-flow process in MODFLOW. Surface water routing in SWR can be simulated using a diffusive-wave approximation of the Saint-Venant equations and/or a simplified level-pool approach. SWR can account for surface water flow controlled by backwater conditions caused by small water-surface gradients or surface water control structures. A number of typical surface water control structures, such as culverts, weirs, and gates, can be represented, and it is possible to implement operational rules to manage surface water stages and streamflow. The nonlinear system of surface water flow equations formulated in SWR is solved by using Newton methods and direct or iterative solvers. SWR was tested by simulating the (1) Lal axisymmetric overland flow, (2) V-catchment, and (3) modified Pinder-Sauer problems. Simulated results for these problems compare well with other published results and indicate that SWR provides accurate results for surface water-only and coupled surface water/groundwater problems. Results for an application of SWR and MODFLOW to the Snapper Creek area of Miami-Dade County, Florida, USA are also presented and demonstrate the value of coupled surface water and groundwater simulation in managed, low-relief coastal settings. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
NASA Astrophysics Data System (ADS)
Vanderhoof, M.; Lane, C.; McManus, M.; Alexander, L. C.; Christensen, J.
2017-12-01
Surface-water extent, duration and movement will depend not only on climatic inputs but also the relative importance of different hydrologic pathways (e.g., surface storage, infiltration, evapotranspiration, stream outflows). We mapped surface-water extent from historic drought years to historic wet years spanning 1985 - 2015 across eleven Landsat path/rows representing the Prairie Pothole Region (PPR) and adjacent Northern Prairie of the United States. The PPR not only experienced a greater surface water extent under median conditions (2.6 times more) relative to the adjacent Northern Prairie, but showed a greater difference between drought and deluge conditions as well (range averaged 8.5 ha surface water km-2 relative to 2.5 ha surface water km-2 for the PPR and Northern Prairie, respectively). To explain the spatial variability in the amount of surface water expansion and contraction we used a two-stage modeling approach. First, surface-water extent was regressed on accumulated water availability (precipitation minus potential evapotranspiration). The slope of surface-water extent to climate inputs (per watershed) was our dependent variable in the second stage. That slope was regressed against independent variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). Stream-connected surface water can leave via stream flow, influencing the rate at which surface-water may leave a location, therefore stream-connected and disconnected surface water were analyzed separately. Stream-connected surface water responded more strongly to wetter climatic conditions (i.e., accumulated) in landscapes with more lakes and less artificial drainage (e.g., ditching, tile drainage). Disconnected surface water responded more strongly to wetter climatic conditions when landscapes contained greater wetland density, fewer streams and a lower predicted rate of infiltration. From these findings, we can expect that the relationship between upstream and downstream waters will require consideration of hydrology-related landscape characteristics, and that climate-change related shifts in precipitation and evaporative demand will have an uneven effect on surface water expansion and contraction across the landscape.
Lynch, C D; Frazier, K B; McConnell, R J; Blum, I R; Wilson, N H F
2010-08-14
Advances of composite systems and their application have revolutionised the management of posterior teeth affected by caries, facilitating a minimally invasive approach. Previous surveys have indicated that the teaching of posterior composites within dental schools was developing, albeit not keeping pace with clinical evidence and the development of increasingly predictable techniques and materials. Concurrently, surveys of dental practice indicate that dental amalgam still predominates as the 'material of choice' for the restoration of posterior teeth within UK general dental practice. In light of such considerations, the aim of this study was to investigate current teaching of posterior composites in Irish and UK dental schools. An online questionnaire which sought information in relation to the current teaching of posterior composites was developed and distributed to the 17 established Irish and UK dental schools with undergraduate teaching programmes in late 2009. Completed responses were received from all 17 schools (response rate = 100%). All 17 schools taught the placement of occlusal and two-surface occlusoproximal composites in premolar and permanent molar teeth. Two schools did not teach placement of three-surface occlusoproximal composites in either premolars or molars. In their preclinical courses, ten schools taught posterior composites before teaching dental amalgams. Fifty-five percent of posterior restorations placed by dental students were of composite (range = 10-90%) and 44% amalgam (range = 10-90%), indicating an increase of 180% in the numbers of posterior composites placed over the past five years. Diversity was noted in the teaching of clinical techniques and students at different schools are trained with different composites and bonding systems. Some cause for concern was noted in the teaching of certain techniques that were not in keeping with existing best evidence, such as the teaching of transparent matrix bands and light-transmitting wedges for occluso-proximal composites (eight schools) and the teaching of bevels on the cavosurface enamel margins of both the occlusal and proximal box margins (three schools). The teaching of posterior composites in the Irish and UK dental schools has substantially increased over the last five years. Dental students in these schools often gain more experience in the placement of posterior composites than amalgam. However, practice trends indicate that a majority of GDPs continue to place amalgam in preference to composite, thereby suggesting a source of tension as current dental students emerge into the dental workforce over the coming years. There is, as a consequence, a challenge to the dental profession and its funding agencies in the UK to encourage more of a shift towards the minimally interventive use of composite systems in the restoration of posterior teeth, in particular among established practitioners.
Ecohydrological controls over water budgets in floodplain meadows
NASA Astrophysics Data System (ADS)
Morris, Paul J.; Verhoef, Anne; Macdonald, David M. J.; Gardner, Cate M.; Punalekar, Suvarna M.; Tatarenko, Irina; Gowing, David
2013-04-01
Floodplain meadows are important ecosystems, characterised by high plant species richness including rare species. Fine-scale partitioning along soil hydrological gradients allows many species to co-exist. Concerns exist that even modest changes to soil hydrological regime as a result of changes in management or climate may endanger floodplain meadows communities. As such, understanding the interaction between biological and physical controls over floodplain meadow water budgets is important to understanding their likely vulnerability or resilience. Floodplain meadow plant communities are highly heterogeneous, leading to patchy landscapes with distinct vegetation. However, it is unclear whether this patchiness in plant distribution is likely to translate into heterogeneous soil-vegetation-atmosphere transfer (SVAT) rates of water and heat, or whether floodplain meadows can reasonably be treated as internally homogeneous in physical terms despite this patchy vegetation. We used a SVAT model, the Soil-Water-Atmosphere-Plants (SWAP) model by J.C. van Dam and co-workers, to explore the controls over the partitioning of water budgets in floodplain meadows. We conducted our research at Yarnton Mead on the River Thames in Oxfordshire, one of the UK's best remaining examples of a floodplain meadow, and which is still managed and farmed in a low-intensity mixed-use manner. We used soil and plant data from our site to parameterise SWAP; we drove the model using in-situ half-hourly meteorological data. We analysed the model's sensitivity to a range of soil and plant parameters - informed by our measurements - in order to assess the effects of different plant communities on SVAT fluxes. We used a novel method to simulate water-table dynamics at the site; the simulated water tables provide a lower boundary condition for SWAP's hydrological submodel. We adjusted the water-table model's parameters so as to represent areas of the mead with contrasting topography, and so different heights above the river level and different moisture and drainage regimes. The model was most sensitive to changes in the parameters that define the water-table model. Plant above-ground parameters, such as leaf area index and canopy height also had strong influences on simulated fluxes. The model exhibited low sensitivity to plant root parameters; this was particularly true during wet periods when the simulated plant communities were oxygen stressed. Changes in soil texture profile exhibited an intermediate level of control over SVAT fluxes. Our findings indicate that unlike in environments with deep water tables, such as drylands and headwater basins, high-quality water-table data with decimetre or even centimetre accuracy are important to accurate simulation of SVAT fluxes. Future studies that seek to simulate SVAT fluxes in shallow groundwater systems should either use high frequency, high-quality water-table observations as part of the driving data set, or should ensure that water-table dynamics and their interactions with surface processes can be simulated in a robust and physically meaningful manner. The low sensitivity of our model to plant root parameters reflects the proximity of the water table to the ground surface and the fact that the simulated plant community is rarely water-stressed, and again contrasts with findings from existing SVAT model research in environments with deep water tables.
Ip, Kenneth; She, Kaiming; Adeyeye, Kemi
2017-10-18
Recovering heat from waste water discharged from showers to preheat the incoming cold water has been promoted as a cost-effective, energy-efficient, and low-carbon design option which has been included in the UK's Standard Assessment Procedure (SAP) for demonstrating compliance with the Building Regulation for dwellings. Incentivized by its carbon cost-effectiveness, waste water heat exchangers (WWHX) have been selected and incorporated in a newly constructed Sports Pavilion at the University of Brighton in the UK. This £2-m sports development serving several football fields was completed in August 2015 providing eight water- and energy-efficient shower rooms for students, staff, and external organizations. Six of the shower rooms are located on the ground floor and two on the first floor, each fitted with five or six thermostatically controlled shower units. Inline type of WWHX were installed, each consisted of a copper pipe section wound by an external coil of smaller copper pipe through which the cold water would be warmed before entering the shower mixers. Using the installation at Sport Pavilion as the case study, this research aims to evaluate the environmental and financial sustainability of a vertical waste heat recovery device, over a life cycle of 50 years, with comparison to the normal use of a PVC-u pipe. A heat transfer mathematical model representing the system has been developed to inform the development of the methodology for measuring the in-situ thermal performance of individual and multiple use of showers in each changing room. Adopting a system thinking modeling technique, a quasi-dynamic simulation computer model was established enabling the prediction of annual energy consumptions under different shower usage profiles. Data based on the process map and inventory of a functional unit of WWHX were applied to a proprietary assessment software to establish the relevant outputs for the life-cycle environmental impact assessment. Life-cycle cost models were developed and industry price book data were applied. The results indicated that the seasonal thermal effectiveness was over 50% enabling significant energy savings through heat recovery that led to short carbon payback time of less than 2 years to compensate for the additional greenhouse gas emissions associated with the WWHX. However, the life-cycle cost of the WWHX is much higher than using the PVC pipe, even with significant heat recovered under heavy usage, highlighting the need to adopt more economic configurations, such as combining waste water through fewer units, in order to maximize the return on investment and improve the financial viability.
NASA Astrophysics Data System (ADS)
Muller, J. B.; O'Shea, S.; Dorsey, J.; Bauguitte, S.; Cain, M.; Allen, G.; Percival, C. J.; Gallagher, M. W.
2012-12-01
A Aerodyne Research© Mini-Quantum Cascade Laser (QCL) spectrometer was installed on the UK Facility of Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft and employed during summer 2012. Methane (CH4) and nitrous oxide (N2O) concentrations were measured within the Arctic Circle as part of the MAMM project (Methane and other greenhouse gases in the Arctic - Measurements, process studies and Modelling) as well as around the UK as part of the ClearfLo project (Clean Air for London). A range of missions were flown, including deep vertical profiles up to the stratosphere, providing concentration profiles of CH4 and N2O, as well as low altitude level runs exploring near surface diffuse emission sources such as the wetlands in Arctic Lapland and point emissions sources such as gas platforms off the UK coast. Significant pollution plumes were observed both in the Arctic and around the UK with elevated CH4 concentrations, as well as enhanced CO, O3 and aerosol levels. The NAME Lagrangian particle dispersion model will be used to investigate the origins of these CH4 plumes to identify the locations of the emissions sources. The first set of flights using QCL on the FAAM research aircraft have been successful and regular in-flight calibrations (high/low span) and target concentrations were used to determine instrument accuracy and precision. Additional data quality control checks could be made by comparison with an onboard Los Gatos Fast Greenhouse Gas Analyser (FGGA) for CO2 and CH4 and provide the basis for further instrument development and implementation for future Arctic MAMM flights during spring and summer 2013.
UK Environmental Prediction - integration and evaluation at the convective scale
NASA Astrophysics Data System (ADS)
Fallmann, Joachim; Lewis, Huw; Castillo, Juan Manuel; Pearson, David; Harris, Chris; Saulter, Andy; Bricheno, Lucy; Blyth, Eleanor
2016-04-01
Traditionally, the simulation of regional ocean, wave and atmosphere components of the Earth System have been considered separately, with some information on other components provided by means of boundary or forcing conditions. More recently, the potential value of a more integrated approach, as required for global climate and Earth System prediction, for regional short-term applications has begun to gain increasing research effort. In the UK, this activity is motivated by an understanding that accurate prediction and warning of the impacts of severe weather requires an integrated approach to forecasting. The substantial impacts on individuals, businesses and infrastructure of such events indicate a pressing need to understand better the value that might be delivered through more integrated environmental prediction. To address this need, the Met Office, NERC Centre for Ecology & Hydrology and NERC National Oceanography Centre have begun to develop the foundations of a coupled high resolution probabilistic forecast system for the UK at km-scale. This links together existing model components of the atmosphere, coastal ocean, land surface and hydrology. Our initial focus has been on a 2-year Prototype project to demonstrate the UK coupled prediction concept in research mode. This presentation will provide an update on UK environmental prediction activities. We will present the results from the initial implementation of an atmosphere-land-ocean coupled system, including a new eddy-permitting resolution ocean component, and discuss progress and initial results from further development to integrate wave interactions in this relatively high resolution system. We will discuss future directions and opportunities for collaboration in environmental prediction, and the challenges to realise the potential of integrated regional coupled forecasting for improving predictions and applications.
US/UK second level panel discussions on the health and value of: Ageing and lifetime predictions (u)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Castro, Richard G
2011-01-18
Many healthy physics, engineering, and materials exchanges are being accomplished in ageing and lifetime prediction that directly supports US and UK Stockpile Management Programs. Lifetime assessment studies of silicon foams under compression - Joint AWE/LANLlLLNL study of compression set in stress cushions completed. Provides phenomenological prediction out to 50 years. Polymer volatile out-gassing studies - New exchange on the out-gassing of Ethylene Vinyl Acetate (EVA) using isotopic {sup 13}C labeling studies to interrogate mechanistic processes. Infra-red (IR) gas cell analytical capabilities developed by AWE will be used to monitor polymer out-gassing profiles. Pu Strength ageing Experiments and Constitutive Modeling -more » In recently compared modeling strategies for ageing effects on Pu yield strength at high strain rates, a US/UK consensus was reached on the general principle that the ageing effect is additive and not multiplicative. The fundamental mechanisms for age-strengthening in Pu remains unknown. Pu Surface and Interface Reactions - (1) US/UK secondment resulted in developing a metal-metal oxide model for radiation damaged studies consistent with a Modified Embedded Atom Method (MEAM) potential; and (2) Joint US/UK collaboration to study the role of impurities in hydride initiation. Detonator Ageing (wide range of activities) - (1) Long-term ageing study with field trials at Pantex incorporating materials from LANL, LLNL, SNL and AWE; (2) Characterization of PETN growth to detonation process; (3) Detonator performance modeling; and (4) Performance fault tree analysis. Benefits are a unified approach to lifetime prediction that Includes: materials characterization and the development of ageing models through improved understanding of the relationship between materials properties, ageing properties and detonator performance.« less
Stefan, Elena; Norby, Truls
2016-01-31
The rising importance of converting high peak electricity from renewables to fuels has urged field specialists to organize this Faraday Discussion on Solid Oxide Electrolysis. The topic is of essential interest in order to achieve a greater utilization of renewable energy and storage at higher densities.
NASA Astrophysics Data System (ADS)
Ito, Shunya; Kasuya, Motohiro; Kurihara, Kazue; Nakagawa, Masaru
2018-02-01
We measured the surface forces generated between fused silica surfaces in a low-viscosity oleophilic diacrylate monomer for reliably repeated ultraviolet (UV) nanoimprinting, and studied the influence of water in monomer liquids on the forces. Fused silica surfaces, with a static contact angle of 52.6 ± 1.7° for water, owing to the low degree of hydroxylation, hardly showed reproducible surface forces with repeated scan cycles, comprising approach and separation, even in an identical liquid monomer medium with both of low and high water content. The monomer liquid with a high water content of approximately 420 ppm showed a greater tendency to increase the surface forces at longer surface-surface distances compared with the monomer liquid with a low water content of approximately 60 ppm. On the other hand, silica surfaces with a water contact angle of < 5° after exposure to vacuum UV (VUV) light under a reduced air pressure showed reproducible profiles of surfaces forces using the monomer with a low water concentration of approximately 60 ppm for repeated surface forces scan cycles even in separately prepared silica surfaces, whilst they showed less reproducible profiles in the liquids with high water content of 430 ppm. These results suggested that water possibly adsorbed on the hydrophilic and hydrophobic silica surfaces in the monomer liquid of the high water concentration influenced the repeatability of the surface forces profiles.
Di Martino, G; Fleming, H; Kamp, M; Lussier, F
2017-11-28
The 2017 Faraday Discussion on Surface Enhanced Raman Scattering (SERS) attracted more than a hundred delegates from a broad spectrum of backgrounds and experience levels, bringing together leading scientists involved in the long living field of SERS. The meeting gave an overview of the liveliness of the topic, characterised by open questions and fascinating science still to discover. In the following, we discuss the topics covered during this meeting and briefly highlight the content of each presentation.
Musarika, S; Atherton, C E; Gomersall, T; Wells, M J; Kaduk, J; Cumming, A M J; Page, S E; Oechel, W C; Zona, D
2017-04-15
Anthropogenic activity is affecting the global climate through the release of greenhouse gases (GHGs) e.g. CO 2 and CH 4 . About a third of anthropogenic GHGs are produced from agriculture, including livestock farming and horticulture. A large proportion of the UK's horticultural farming takes place on drained lowland peatlands, which are a source of significant amounts of CO 2 into the atmosphere. This study set out to establish whether raising the water table from the currently used -50cm to -30cm could reduce GHGs emissions from agricultural peatlands, while simultaneously maintaining the current levels of horticultural productivity. A factorial design experiment used agricultural peat soil collected from the Norfolk Fens (among the largest of the UK's lowland peatlands under intensive cultivation) to assess the effects of water table levels, elevated CO 2 , and agricultural production on GHG fluxes and crop productivity of radish, one of the most economically important fenland crops. The results of this study show that a water table of -30cm can increase the productivity of the radish crop while also reducing soil CO 2 emissions but without a resultant loss of CH 4 to the atmosphere, under both ambient and elevated CO 2 concentrations. Elevated CO 2 increased dry shoot biomass, but not bulb biomass nor root biomass, suggesting no immediate advantage of future CO 2 levels to horticultural farming on peat soils. Overall, increasing the water table could make an important contribution to global warming mitigation while not having a detrimental impact on crop yield. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Alshatti, Amani
2017-04-01
Seasonal changes in bacterioplankton populations in two south coast UK estuaries Southampton Water and Christchurch Harbour have been investigated between March and November 2013. Four different phylogenetic bacterial groups with two alphaproteobacteria clades were quantitatively determined in subsurface water samples by Fluorescence in-situ hybridization (FISH) with oligonucleotide probes during phytoplankton bloom periods. During the spring phytoplankton bloom in Southampton water, extracted chlorophyll-a concentrations of between 6.7 and 7.6 µg L-1 were detected while gammaproteobacteria relative abundances (28.7-32.8%) and alphaproteobacteria (35.0-44.0%) dominated the eubacteria with smaller proportions of betaproteobacteria (6.4-13.0%) under high salinity conditions (27.9-32.7). Gammaproteobacteria abundance was significantly negatively correlated with chlorophyll-a concentration (R =-0.5, p < 0.05). In the Christchurch Harbour estuary, betaproteobacteria (21.2-41.1%) dominated throughout the study period in lower salinity waters (1.3-20.7). A significant relationship with negative trend was detected in both estuaries between salinity and betaproteobacteria (R = - 0.95, p < 0.0001). A higher proportion of gammaproteobacteria (29.7-30.3 %) occurred after the spring bloom chlorophyll-a concentration of 5-44.3 µg L-1 and proportion of alphaproteobacteria was highly variable. Archaea were detected in low percentages throughout the blooming season in both estuaries with maximum detected relative abundances of 10.6% in Southampton water and 8.2% in Christchurch harbour. The variation in salinity range therefore between the two estuaries plus the differences in phytoplankton biomass had a marked influence on the dominance of the different proteobacterial groups detected.
A degassing instrument for analysing CO2 dissolved in natural water
NASA Astrophysics Data System (ADS)
Durham, Brian; Pfrang, Christian
2017-04-01
Arising from our EGU 2017 presentation (http://meetingorganizer.copernicus.org/EGU2016/posters/20564, X2 352), interest has been expressed in its application to the analysis of the hydrocarbonate ion [HCO3-] in atmospheric water. Arising from the historic difficulty in analysing the aqueous [HCO3-] ion ('it is in all our reagents', pers. comm. UK laboratory) the classic determination has been to measure a suite of other anions and cations including [H+] via pH, and to treat the balance of negative charge as a measure of [HCO3-]. From this balance, dissolved CO2 can be inferred via the dissociation constant as published for pure water. CO2 + H2O ⇓♢[HCO3-] + [H+] K1 = 4.2 x 10-7 Our EGU 2016 presentation sought to determine how the ionic environment in 263 UK rain samples can influence the above equilibrium, which is work in progress. In the mean time we have received the following expression of interest from an atmospheric science advisory group. …….. is very interested in the role of H-carbonate in the ion balance of precipitation. They have had some discussions recently about the best approach to infer H-carbonate currently discussing the possibility of sending you samples from other locations for analysis. We have duly offered to use our degassing instrument to corroborate current analyses in a batch of 'blind' samples, and to provide a design for a basic degasser that water quality laboratories could evaluate in house. This paper therefore presents a circuit for degassing CO2 from water samples irrespective of whether in atmospheric equilibrium or supersaturated, including a prototype 4-way distribution and collection valve which it is hoped will make the analysis intuitive and therefore open to automation.
Robinson, Marci; Caballero, Rocio; Pohlman, Emily; Herbert, Timothy; Peck, Victoria; Dowsett, Harry
2008-01-01
The U.S. Geological Survey is conducting a long-term study of mid-Pliocene climatic and oceanographic conditions. One of the key elements of the study involves the use of quantitative composition of planktic foraminifer assemblages in conjunction with other proxies to constrain estimates of sea-surface temperature (SST) and to identify major oceanographic boundaries and water masses. Raw census data are made available as soon as possible after analysis through a series of reports that provide the basic data for future work. In this report we present raw census data (table 1) for planktic foraminifer assemblages in 14 samples from Ocean Drilling Program (ODP) Hole 677A. We also present alkenone unsaturation index (UK'37) analyses for 89 samples from ODP Hole 677A (table 2). ODP Hole 677A is located in the Panama basin, due west of Ecuador at 1?12.138'N., 83?44.220'W., in 3461.2 meters of water (fig. 1). A variety of statistical methods have been developed to transform foraminiferal census data in Pliocene sequences into quantitative estimates of Pliocene SST. Details of statistical techniques, taxonomic groupings, and oceanographic interpretations are presented in more formal publications (Dowsett and Poore, 1990, 1991; Dowsett, 1991, 2007a,b; Dowsett and Robinson, 1998, 2007; Dowsett and others, 1996, 1999).
NASA Astrophysics Data System (ADS)
Sabbaghzadeh, B.; Upstill-Goddard, R. C.; Nightingale, P. D.; Beale, R.
2016-02-01
Surfactants that decrease air-sea gas exchange by suppressing the gas transfer velocity (kw) show variable enrichments in the sea surface microlayer (SML) relative to the underlying water. This reflects variability in the rates of surfactant production and consumption. Total surfactant activity (SA: equivalent to Triton-X-100, mgL -1) was determined daily between the UK and the Falkland Islands, during cruise 24 of the Atlantic Meridional Transect programme (AMT 24). Samples were simultaneously obtained from the SML (Garrett screen), from the ship's underway system (inlet at 7m) and in hydrocasts to 500m. SA analysis was by hanging mercury drop electrode polarography (Metrohm 797 VA Computrace). SA enrichment factors (EF: SML SA / underlying water SA) >1 were observed at most locations, showing the SML to be consistently SA-enriched along the entire cruise transect. The persistence of these enrichments up to wind speeds 12m s-¹ support previous conclusions regarding the stability of the SML under high winds. More specifically, SA in the SML was up to four-fold higher in the Atlantic Northern Hemisphere than in the Atlantic Southern Hemisphere. Even so, EF values were not significantly different between the two hemispheres (p >0.05). These various findings have potentially important implications for kw variability across ocean basin scales.
Lack of Precision of Burn Surface Area Calculation by UK Armed Forces Medical Personnel
2014-03-01
computer screen or tablet , and therefore the variability in perception and representation inherent in having a human assess and draw the burn remains...Potential solutions to this source of error include 3D MRI and TeraHertz scanning technologies [40], but at the time of writing, these are not yet
ERIC Educational Resources Information Center
Pegg, Ann; Di Paolo, Terry
2013-01-01
This paper seeks to advance our understanding of the credit transfer phenomenon in the UK, specifically how students draw on a credit as a form of institutional cultural capital. Drawing on interviews with 26 part-time mature learners, this paper examines the progressive and retrospective orientations to study that surfaced in students' accounts…
NASA Technical Reports Server (NTRS)
Tao, W.-K.
2006-01-01
Real clouds and cloud systems are inherently three-dimensional (3D). Because of the limitations in computer resources, however, most cloud-resolving models (CRMs) today are still two-dimensional (2D). A few 3D CRMs have been used to study the response of clouds to large-scale forcing. In these 3D simulations, the model domain was small, and the integration time was 6 hours. Only recently have 3D experiments been performed for multi-day periods for tropical cloud systems with large horizontal domains at the National Center for Atmospheric Research (NCAR), NOAA GFDL, the U.K. Met. Office, Colorado State University and NASA Goddard Space Flight Center. An improved 3D Goddard Cumulus Ensemble (GCE) model was recently used to simulate periods during TOGA COARE (December 19-27, 1992), GATE (september 1-7, 1974), SCSMEX (May 18-26, June 2-11, 1998) and KWAJEX (August 7-13, August 18-21, and August 29-September 12, 1999) using a 512 by 512 km domain and 41 vertical layers. The major objectives of this paper are: (1) to identify the differences and similarities in the simulated precipitation processes and their associated surface and water energy budgets in TOGA COARE, GATE, KWAJEX, and SCSMEX, and (2) to asses the impact of microphysics, radiation budget and surface fluxes on the organization of convection in tropics.
Voltage-induced swelling and deswelling of weak polybase brushes.
Weir, Michael P; Heriot, Sasha Y; Martin, Simon J; Parnell, Andrew J; Holt, Stephen A; Webster, John R P; Jones, Richard A L
2011-09-06
We have investigated a novel method of remotely switching the conformation of a weak polybase brush using an applied voltage. Surface-grafted polyelectrolyte brushes exhibit rich responsive behavior and show great promise as "smart surfaces", but existing switching methods involve physically or chemically changing the solution in contact with the brush. In this study, high grafting density poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes were grown from silicon surfaces using atom transfer radical polymerization. Optical ellipsometry and neutron reflectivity were used to measure changes in the profiles of the brushes in response to DC voltages applied between the brush substrate and a parallel electrode some distance away in the surrounding liquid (water or D(2)O). Positive voltages were shown to cause swelling, while negative voltages in some cases caused deswelling. Neutron reflectometry experiments were carried out on the INTER reflectometer (ISIS, Rutherford Appleton Laboratory, UK) allowing time-resolved measurements of polymer brush structure. The PDMAEMA brushes were shown to have a polymer volume fraction profile described by a Gaussian-terminated parabola both in the equilibrium and in the partially swollen states. At very high positive voltages (in this study, positive bias means positive voltage to the brush-bearing substrate), the brush chains were shown to be stretched to an extent comparable to their contour length, before being physically removed from the interface. Voltage-induced swelling was shown to exhibit a wider range of brush swelling states in comparison to pH switching, with the additional advantages that the stimulus is remotely controlled and may be fully automated. © 2011 American Chemical Society
PWR design for low doses in the United Kingdom: The present and the future
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zodiates, A.M.; Willcock, A.
1995-03-01
The Pressurizer Water Reactor (PWR) design chosen for adoption by Nuclear Electric plc was based on the Westinghouse Standard Nuclear Unit Power Plant System (SNUPPS). This design was developed to meet the United Kingdom (UK) requirements and those improvements are embodied in the Sizewell B plant. Nuclear Electric plc is now looking to the design of the future PWRs to be built in the UK. These PWRs will be based as replicas of the Sizewell B design, but attention will be given to reducing operator doses further. This paper details the approach in operator protection improvements incorporated at Sizewall B,more » presents the estimated annual collective dose, and identifies the approach being adopted to reduce further operator doses in future plants.« less
The NERC Data Assimilation Research Centre and Envisat
NASA Astrophysics Data System (ADS)
LAHOZ, W. A.
2001-12-01
The NERC Data Assimilation Research Centre (DARC), a Centre of Excellence in Earth Observation, has been recently set up in the UK. DARC is a distributed centre, with participation from the universities of Reading, Oxford, Cambridge and Edinburgh, and the Rutherford Appleton Laboratory. It has strong links with the UK Met Office, and with European data assimilation groups. One of the remits of DARC is the exploitation of research satellite data (e.g. from ESA's Envisat, due to be launched in November 2001). This presentation will describe the participation of DARC in the Envisat programme. This participation involves: (1) the calibration/validation of Envisat data using an NWP assimilation system, and (2) the production of 4-d quality-controlled datasets of temperature, ozone and water vapour from Envisat using an NWP assimilation system.
Ozbilgin, M.M.; Dickerman, D.C.
1984-01-01
The two-dimensional finite-difference model for simulation of groundwater flow was modified to enable simulation of surface-water/groundwater interactions during periods of low streamflow. Changes were made to the program code in order to calculate surface-water heads for, and flow either to or from, contiguous surface-water bodies; and to allow for more convenient data input. Methods of data input and output were modified and entries (RSORT and HDRIVER) were added to the COEF and CHECKI subroutines to calculate surface-water heads. A new subroutine CALC was added to the program which initiates surface-water calculations. If CALC is not specified as a simulation option, the program runs the original version. The subroutines which solve the ground-water flow equations were not changed. Recharge, evapotranspiration, surface-water inflow, number of wells, pumping rate, and pumping duration can be varied for any time period. The Manning formula was used to relate stream depth and discharge in surface-water streams. Interactions between surface water and ground water are represented by the leakage term in the ground-water flow and surface-water mass balance equations. Documentation includes a flow chart, data deck instructions, input data, output summary, and program listing. Numerical results from the modified program are in good agreement with published analytical results. (USGS)
NASA Astrophysics Data System (ADS)
Whitehead, P. G.; Jin, L.; Futter, M.; Crossman, J.
2011-12-01
A modelling study has been undertaken as part of a UK Water Industry Research Project to study and assess the likely impacts of climate change on river water quality across the UK. A range of climate scenarios (http://ukclimateprojections.defra.gov.uk/ ) have been used to generate future precipitation, evaporation and temperature time series at a range of catchments across the UK. These time series have then been used to drive the Integrated Catchment Model (INCA) suite to simulate flow, nitrate, ammonia, total and soluble reactive phosphorus, sediments, dissolved organic carbon (DOC) in the Rivers Tamar, Lugg, Tame, Kennet, Tweed and Lambourn. A wide range of responses have been obtained with impacts varying depending on river character, catchment location, flow regime, type of scenario and the time into the future. For example, The INCA-DOC model has been applied to the Hore catchment of the upper Severn catchment at Plynlimon, Wales. DOC is becoming an issue in the UK uplands due to rising trends in recent years. The trends are thought to be due primarily to reducing sulphur deposition but the climate variability certainly has an effect. This is because when peats dry out the oxidation processes enhance the production of DOC. The INCA-DOC model has been used to assess potential changes in DOC under the 2020s and 2050s climate. These results show quite large rises in October and September months when the soils become saturated and flush DOC. The INCA-N results for the Rivers Tweed (Scotland) and Kennet (England) suggest that nitrate and ammonia concentrations will be slightly higher in the winter months under the climate change scenarios, perhaps reflecting the higher flushing of nitrogen load from the catchment soils. However, in summer month nitrates fall significantly which reflects enhanced denitrification processes in the rivers. However, lower down the rivers where major point sources from effluents affect the river, nitrates and ammonia may increase because of lower flows in summer and hence less dilution. Modelling phosphorus and sediments in the Rivers Lugg, Tame and the Wensum (England) suggest phosphorus concentrations will decrease in summer due to lower flows in rural areas and the reduced flushing of diffuse sources of P from agricultural areas. However, in catchments with significant effluent discharges, the P concentrations will increase due to the reduced dilution of effluents. Sediments will increase with intense rainfall during winter months, although the increased frequency of storms, especially in summer months, will generate higher concentrations as sediments are flushed from the catchments. However, mean summer sediment concentrations will be lower due to the reduced diffuse runoff from agricultural areas. Finally it is worth pointing out that adaptation measures are possible with mitigation measures to control N deposition, fertiliser application rates, reintroducing wetlands and land management control.
SeaShark and Starfish opertional data processing schemes for AVHRR and SeaWiFs
NASA Astrophysics Data System (ADS)
Flowerdew, R. J.; Corlyon, Anaa M.; Greer, W. A. D.; Newby, Steve J.; Winder, C. P.
1997-02-01
SeaShark is an operational software package for processing, archiving and cataloguing AVHRR and SeaWiFS data using an operator friendly GUI. Upon receipt of a customer order, it produces standard AVHRR data products, including Sea Surface Temperature (SST) and it has recently been modified to include SeaWiFS level 2 data processing. This uses an atmospheric correction scheme developed by the Plymouth Marine Laboratory, UK (PML) that builds upon the standard Gordon and Wang approach to be applicable over both case 1 and case 2 waters. Higher level products are then generated using PML algorithms, including chlorophyll a, a CZCS-type pigment, Kd, and suspended particulate matter. Outputs are in CEOS-compatible format. The software also produces fast delivery products (FDPs) of chlorophyll a and SST. These FDPs are combined in the StarFish software package to provide maps indicating potential location of phytoplankton and the preferred thermal environment of certain pelagic fish species. Fishing vessels may obtain these maps over Inmarsat, allowing them to achieve a greater efficiency hence lower cost.
Metcalfe, David; Rockey, Chris; Jefferson, Bruce; Judd, Simon; Jarvis, Peter
2015-12-15
This investigation aimed to compare the disinfection by-product formation potentials (DBPFPs) of three UK surface waters (1 upland reservoir and 2 lowland rivers) with differing characteristics treated by (a) a full scale conventional process and (b) pilot scale processes using a novel suspended ion exchange (SIX) process and inline coagulation (ILCA) followed by ceramic membrane filtration (CMF). Liquid chromatography-organic carbon detection analysis highlighted clear differences between the organic fractions removed by coagulation and suspended ion exchange. Pretreatments which combined SIX and coagulation resulted in significant reductions in dissolved organic carbon (DOC), UV absorbance (UVA), trihalomethane and haloacetic acid formation potential (THMFP, HAAFP), in comparison with the SIX or coagulation process alone. Further experiments showed that in addition to greater overall DOC removal, the processes also reduced the concentration of brominated DBPs and selectively removed organic compounds with high DBPFP. The SIX/ILCA/CMF process resulted in additional removals of DOC, UVA, THMFP, HAAFP and brominated DBPs of 50, 62, 62, 62% and 47% respectively compared with conventional treatment. Copyright © 2015. Published by Elsevier Ltd.
NASA Astrophysics Data System (ADS)
Milne, A.; Palmer, M.; Lohan, M. C.
2016-02-01
Particles play a fundamental role in the biogeochemical cycling of both major- and micro-nutrients in marine systems, including trace elements and isotopes. However, knowledge of particulate distributions, and their potential to regulate dissolved elemental concentrations, remains limited and poorly understood. The paradox is, that the oceanic inventory of trace metals is dominated by particulate inputs (e.g. aerosol deposition, shelf sediment resuspension). Moreover the labile fraction of particulate trace elements could be an important regulator of dissolved concentrations. Here we present particulate data from the UK GEOTRACES South Atlantic transect (GA10) from South Africa to Uruguay. Data from a range of elements (e.g. Fe, Al, Mn) revealed a greater input of particulate metals from the Argentine shelf (up to 290 nM of pFe) in comparison to the South African shelf (< 40 nM of pFe). Overall, higher concentrations of all metals were observed in the bottom waters of the Argentine basin and penetrated deeper up the water column (up to 1300 m), a result of intense benthic storms. The imprint of leakage from the Agulhas Current, identified through temperature and salinity, was observed in the upper water column profile of numerous particulate data (e.g. Pb, Ni, Cd). Measured elemental gradients, combined with measurements from a vertical mixing-profiler, will allow estimates of particulate fluxes to be calculated.
Wetlands inform how climate extremes influence surface water expansion and contraction
Vanderhoof, Melanie; Lane, Charles R.; McManus, Michael L.; Alexander, Laurie C.; Christensen, Jay R.
2018-01-01
Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage. From these findings, we can expect that shifts in precipitation and evaporative demand will have uneven effects on surface water quantity. Accurate predictions regarding the effect of climate change on surface water quantity will require consideration of hydrology-related landscape characteristics including wetland storage and arrangement.
NASA Technical Reports Server (NTRS)
Segal, M.; Pielke, R. A.
1985-01-01
Simulations of the thermally induced breeze involved with a relatively narrow, elongated water body is presented in conjunction with evaluations of sensible heat fluxes in a stable marine atmospheric surface layer. The effect of the water surface temperature and of the large-scale synoptic winds on the development of surface flows over the water is examined. As implied by the sensible heat flux patterns, the simulation results reveal the following trends: (1) when the synoptic flow is absent or light, the induced surface breeze is not affected noticeably by a reduction of the water surface temperature; and (2) for stronger synoptic flow, the resultant surface flow may be significantly affected by the water surface temperature.
First-principles study of water desorption from montmorillonite surface.
Zhang, Yao; Meng, Yingfeng; Liu, Houbin; Yang, Mingli
2016-05-01
Knowledge about water desorption is important to give a full picture of water diffusion in montmorillonites (MMT), which is a driving factor in MMT swelling. The desorption paths and energetics of water molecules from the surface of MMT with trapped Li(+), Na(+) or K(+) counterions were studied using periodic density functional theory calculations. Two paths--surface and vacuum desorption--were designed for water desorption starting from a stationary structure in which water bonds with both the counterion and the MMT surface. Surface desorption is energetically more favorable than vacuum desorption due to water-surface hydrogen bonds that help stabilize the intermediate structure of water released from the counterion. The energy barriers of water desorption are in the order of Li(+) > Na(+) > K(+), which can be attributed to the short ionic radius of Li(+), which favors strong binding with the water molecule. The temperature dependence of water adsorption and desorption rates were compared based on the computed activation energies. Our calculations reveal that the water desorption on the MMT surface has a different mechanism from water adsorption, which results from surface effects favoring stabilization of water conformers during the desorption process.
Long, Jiangyou; Fan, Peixun; Gong, Dingwei; Jiang, Dafa; Zhang, Hongjun; Li, Lin; Zhong, Minlin
2015-05-13
Superhydrophobic surfaces with tunable water adhesion have attracted much interest in fundamental research and practical applications. In this paper, we used a simple method to fabricate superhydrophobic surfaces with tunable water adhesion. Periodic microstructures with different topographies were fabricated on copper surface via femtosecond (fs) laser irradiation. The topography of these microstructures can be controlled by simply changing the scanning speed of the laser beam. After surface chemical modification, these as-prepared surfaces showed superhydrophobicity combined with different adhesion to water. Surfaces with deep microstructures showed self-cleaning properties with extremely low water adhesion, and the water adhesion increased when the surface microstructures became flat. The changes in surface water adhesion are attributed to the transition from Cassie state to Wenzel state. We also demonstrated that these superhydrophobic surfaces with different adhesion can be used for transferring small water droplets without any loss. We demonstrate that our approach provides a novel but simple way to tune the surface adhesion of superhydrophobic metallic surfaces for good potential applications in related areas.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Raoult, Nina M.; Jupp, Tim E.; Cox, Peter M.
Land-surface models (LSMs) are crucial components of the Earth system models (ESMs) that are used to make coupled climate–carbon cycle projections for the 21st century. The Joint UK Land Environment Simulator (JULES) is the land-surface model used in the climate and weather forecast models of the UK Met Office. JULES is also extensively used offline as a land-surface impacts tool, forced with climatologies into the future. In this study, JULES is automatically differentiated with respect to JULES parameters using commercial software from FastOpt, resulting in an analytical gradient, or adjoint, of the model. Using this adjoint, the adJULES parameter estimationmore » system has been developed to search for locally optimum parameters by calibrating against observations. This paper describes adJULES in a data assimilation framework and demonstrates its ability to improve the model–data fit using eddy-covariance measurements of gross primary production (GPP) and latent heat (LE) fluxes. adJULES also has the ability to calibrate over multiple sites simultaneously. This feature is used to define new optimised parameter values for the five plant functional types (PFTs) in JULES. The optimised PFT-specific parameters improve the performance of JULES at over 85 % of the sites used in the study, at both the calibration and evaluation stages. Furthermore, the new improved parameters for JULES are presented along with the associated uncertainties for each parameter.« less