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Sample records for catchment basin preliminary

  1. Evaluation of soil erosion as a basis of sediment yield in mountainous catchments: a preliminary study in the River Douro Basin (Northern Portugal)

    NASA Astrophysics Data System (ADS)

    Reis, Anabela; Martinho Lourenço, José M.; Parker, Andrew; Alencoão, Ana

    2013-04-01

    The River Corgo drains a meso-scale mountainous rural catchment with an area of 295 km2, underlain by crystalline rocks, in a temperate climate, which integrates the transboundary River Douro Basin, in the northeast of Portugal. A geochemical survey on oxic fluvial sediments of the river network shows considerable contents of metals associated to the finer particles (< 63um). The results on the study of the sediment properties indicate that these are essentially detrital in origin, derived from soils and weathering products. Moreover, taking into account the hydrological pattern of the catchment, the seasonal and spatial variability of metal contents associated to the sediments suggests that the control of metal in the sediments by their mineralogical, geochemical and physical properties is governed primarily at the level of the basin soils system, especially in the Wet Period, when the sediments are frequently remobilised (Reis, 2010). Although the soil particles are a common pathway of transport and entrance of metals in the fluvial network by runoff derived erosion, this mechanism is naturally more marked in mountainous catchments. Modelling sediment and adsorbed contaminant transport within catchments can help to identify possible contaminant sources, as well as to estimate the delivered quantities of eroded material and associated contaminants. In catchments with the described morphological features, monitoring the transport of sediments poses some issues concerning: (a) the low mass yield of suspended sediment from river water, under low-flow conditions; (b) the maintenance of the sediment sampler's devices in the streams, in periods of high-flow or storm events. This study describes the preliminary results of a GIS-based mass balance model of overland sediment transport to the River. The erosion, the first step of sediment transport, was estimated by an empirical model - The Universal Soil Loss Equation (USLE). The objective was to construct a GIS based potential soil loss spatial index model and posteriorly estimate the sediment yield for different locations within the catchment. The R factor was obtained from the literature; K factor was derived from the Soil Map of Trás-os-Montes; LS factor was calculated from the elevation digital model using the Simms et al. (2003) equation; C and P factors were derived from the Corin Land Cover Map produced for Portugal in 2006. The preliminary results indicate that the model is in accordance with the knowledge of the study area, and can be used as an initial indicator of areas of potential sediment source. So, the results show that potential loss is typically higher along the areas where the tributaries are deeply incised and bordered by steeper slopes, with locally extreme values. REFERENCES REIS, A. R. (2010) - Occurrence and mobilisation of non-organic micro-pollutants in mountainous riverine systems. PhD Thesis (unpublished), University of Trás-os-Montes e Alto Douro, Vila Real, 453 pp. SIMMS, A., WOODROFFE, C. & JONES, B. (2003) - Application of RUSLE for erosion management in a coastal catchment, southern NSW. MODSIM 2003: Intern. Congress on Modelling and Simulation, vol.2, Integrative Modelling of Biophysical, Social and Economic Systems for Resource Management Solutions, Australia, pp. 678-683.

  2. Are big basins just the sum of small catchments?

    USGS Publications Warehouse

    Shaman, J.; Stieglitz, M.; Burns, D.

    2004-01-01

    Many challenges remain in extending our understanding of how hydrologic processes within small catchments scale to larger river basins. In this study we examine how low-flow runoff varies as a function of basin scale at 11 catchments, many of which are nested, in the 176 km2 Neversink River watershed in the Catskill Mountains of New York. Topography, vegetation, soil and bedrock structure are similar across this river basin, and previous research has demonstrated the importance of deep groundwater springs for maintaining low-flow stream discharge at small scales in the basin. Therefore, we hypothesized that deep groundwater would contribute an increasing amount to low-flow discharge as basin scale increased, resulting in increased runoff. Instead, we find that, above a critical basin size of 8 to 21 km2, low-flow runoff is similar within the Neversink watershed. These findings are broadly consistent with those of a previous study that examined stream chemistry as a function of basin scale for this watershed. However, we find physical evidence of self-similarity among basins greater than 8 km2, whereas the previous study found gradual changes in stream chemistry among basins greater than 3 km 2. We believe that a better understanding of self-similarity and the subsurface flow processes that affect stream runoff will be attained through simultaneous consideration of both chemical and physical evidence. We also suggest that similar analyses of stream runoff in other basins that represent a range of spatial scales, geomorphologies and climate conditions will further elucidate the issue of scaling of hydrologic processes. Copyright ?? 2004 John Wiley & Sons, Ltd.

  3. Isotope hydrology of catchment basins: lithogenic and cosmogenic isotopic systems

    SciTech Connect

    Nimz, G. J., LLNL

    1998-06-01

    A variety of physical processes affect solute concentrations within catchment waters. The isotopic compositions of the solutes can indicate which processes have determined the observed concentrations. These processes together constitute the physical history of the water. Many solutes in natural waters are derived from the interaction between the water and the rock and/or soil within the system - these are termed `lithogenic` solutes. The isotopic compositions of these solutes provide information regarding rock-water interactions. Many other solutes have their isotopic compositions determined both within and outside of the catchment - i.e., in addition to being derived from catchment rock and soil, they are solutes that are also transported into the catchment. Important members of this group include solutes that have isotopic compositions produced by atomic particle interactions with other nuclides. The source of the atomic particles can be cosmic radiation (producing `cosmogenic` nuclides in the atmosphere and land surface), anthropogenic nuclear reactions (producing `thermonuclear` nuclides), or radioactive and fission decay of naturally-occurring elements, principally {sup 238}U (producing `in-situ` lithogenic nuclides in the deep subsurface). Current language usage often combines all of the atomic particle-produced nuclides under the heading `cosmogenic nuclides`, and for simplicity we will often follow that usage here, although always indicating which variety is being discussed. This paper addresses the processes that affect the lithogenic and cosmogenic solute concentrations in catchment waters, and how the isotopic compositions of the solutes can be used in integrative ways to identify these processes, thereby revealing the physical history of the water within a catchment system. The concept of a `system` is important in catchment hydrology. A catchment is the smallest landscape unit that can both participate in all of the aspects of the hydrologic cycle and also be treated as a mostly closed system for mass balance considerations. It is the near closure of the system that permits well- constrained chemical mass balance calculations to be made. These calculations generally focus of lithogenic solutes, and therefore in our discussions of lithogenic nuclides in the paper, the concept of chemical mass balance in a nearly dosed system will play an important role. Examination of the isotopic compositions of solutes provides a better understanding of the variety of processes controlling mass balance. It is with this approach that we examined the variety of processes occurring within the catchment system, such as weathering and soil production, generation of stormflow and streamflow (hydrograph separation), movement of soil pore water, groundwater flow, and the overall processes involved with basinal water balance. In this paper, the term `nuclide` will be used when referring to a nuclear species that contains a particular number of protons and neutrons. The term is not specific to any element. The term `isotope` will be used to distinguish nuclear species of a given element (atoms with the same number of protons). That is to say, there are many nuclides in nature - for example, {sup 36}Cl, {sup 87}Sr, {sup 238}U; the element has four naturally-occurring isotopes - {sup 87}Sr, and {sup 88}Sr. This paper will first discuss the general principles that underlie the study of lithogenic and cosmogenic nuclides in hydrology, and provide references to some of the more important studies applying these principles and nuclides. We then turn in the second section to a discussion of their specific applications in catchment- scale systems. The final section of this paper discusses new directions in the application of lithogenic and cosmogenic nuclides to catchment hydrology, with some thoughts concerning possible applications that still remain unexplored.

  4. Exploratory shaft facility preliminary designs - Permian Basin

    SciTech Connect

    Not Available

    1983-09-01

    The purpose of the Preliminary Design Report, Permian Basin, is to provide a description of the preliminary design for an Exploratory Shaft Facility in the Permian Basin, Texas. This issue of the report describes the preliminary design for constructing the exploratory shaft using the Large Hole Drilling method of construction and outlines the preliminary design and estimates of probable construction cost. The Preliminary Design Report is prepared to complement and summarize other documents that comprise the design at the preliminary stage of completion, December 1982. Other design documents include drawings, cost estimates and schedules. The preliminary design drawing package, which includes the construction schedule drawing, depicts the descriptions in this report. For reference, a list of the drawing titles and corresponding numbers are included in the Appendix. The report is divided into three principal sections: Design Basis, Facility Description, and Construction Cost Estimate. 30 references, 13 tables.

  5. Coupling catchment hydrology and landscape evolution: Interactive effects on hydrograph and basin shape

    NASA Astrophysics Data System (ADS)

    Vivoni, E. R.; Istanbulluoglu, E.; Bras, R. L.

    2003-12-01

    The catchment hydrologic response to rainfall and the evolution of the river basin network and landscape morphology are closely linked phenomena, albeit active over different temporal scales. While the relation between hydrograph shape and catchment form has long been hypothesized, little is yet understood about the evolution of the basin hydrologic response with catchment age or geomorphic condition. Similarly, the long-term morphologic changes and feedbacks associated with a spatially-variable, evolving runoff response are still unknown. Understanding the complex interaction between basin hydrology and geomorphology was an important pursuit during Michael J. Kirkby's scientific career. In this study, we describe the interactive effects and feedbacks between the basin hydrograph (hydrologic response) and shape (geomorphic response) utilizing two state-of-the-art models: the Channel-Hillslope Integrated Landscape Development (CHILD) and the TIN-based Real-time Integrated Basin Simulator (tRIBS). We first illustrate the changes occurring in the basin hydrograph, variable source area and channel network as the catchment evolves. We then describe how the spatially-explicit hydrologic response from various mechanisms and its associated moisture field directly impacts the erosion and subsequently the basin shape. Quantitative comparisons are then made between a set of interactive and non-interactive simulations for idealized conditions. Our ultimate goal is to highlight the need for coupling distributed simulations of catchment hydrology and geomorphology for investigating the interaction between basin and hydrograph shape.

  6. PSYCHIC A process-based model of phosphorus and sediment transfers within agricultural catchments. Part 2. A preliminary evaluation

    NASA Astrophysics Data System (ADS)

    Strmqvist, J.; Collins, A. L.; Davison, P. S.; Lord, E. I.

    2008-02-01

    SummaryThis paper describes the preliminary evaluation of the PSYCHIC catchment scale (Tier 1) model for predicting the mobilisation and delivery of phosphorus (P) and suspended sediment (SS) in the Hampshire Avon (1715 km 2) and Herefordshire Wye (4017 km 2) drainage basins, in the UK, using empirical data. Phosphorus and SS transfers to watercourses in the Wye were predicted to be greater than corresponding delivery in the Avon; SS, 249 vs 33 kg ha -1 yr -1; DP, 2.57 vs 1.26 kg ha -1 yr -1; PP, 2.20 vs 0.56 kg ha -1 yr -1. The spatial pattern of the predicted transfers was relatively uniform across the Wye drainage basin, whilst in the Avon, delivery to watercourses was largely confined to the river corridors and small areas of drained land. Statistical performance in relation to predicted exports of P and SS, using criteria for relative error (RE) and root mean square error (RMSE), reflected the potential shortcomings associated with using longer-term climate data for predicting shorter-term (2002-2004) catchment response and the need to refine calculations of point source contributions and to incorporate additional river basin processes such as channel bank erosion and in-stream geochemical processing. PSYCHIC is therefore best suited to characterising longer-term catchment response.

  7. Modelling Rainfall-Runoff from Large Catchment to Basin Scale: the Goulburn Valley, Victoria

    NASA Astrophysics Data System (ADS)

    Schreider, S. Yu.; Jakeman, A. J.; Pittock, A. B.

    1996-06-01

    A lumped parameter dynamic rainfall-runoff model, IHACRES, is applied to the large upland area (more than 4500 km2) of the Goulburn Valley Basin, Victoria, Australia to predict streamflow under different climatic conditions. This paper presents the first evaluation of a rainfall-runoff model at large catchment scale, which is comprehensive in terms of the number of catchments investigated and the number of calibration and simulation periods used. The basin is subdivided into 12 catchments (from 100 to 700 km2), each of which is calibrated separately. High values of model efficiency and low bias are consistently obtained for different calibration sub-periods for all catchments in the basin. Simulation or so-called validation tests are used to select the best models for each catchment. This allows simulation of the water regime during long historical (approximately 90 year) periods when only climatological (rainfall and temperature) data were available. This procedure is extremely important for the estimation of the effect of climate variability and of the possible impact of climate change on the hydrological regime in the region and, in particular, for supporting irrigation management of the basin. Analysis of a composite catchment (2417 km2) and its five separate subcatchments indicates that the information content in the rainfall-streamflow data is independent of catchment size. Dynamic modelling of the daily water balance at the macroscale is limited principally by the adequacy of the precipitation gauging network. When a good estimate of areal precipitation is available for a catchment, it is not necessary to consider subcatchment-scale variability for modelling if the only interest is the daily discharge and evaporation losses from the catchment.

  8. Attributes for NHDPlus Catchments (Version 1.1): Basin Characteristics, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This data set represents basin characteristics, compiled for every catchment in NHDPlus for the conterminous United States. These characteristics are basin shape index, stream density, sinuosity, mean elevation, mean slope, and number of road-stream crossings. The source data sets are the U.S. Environmental Protection Agency's NHDPlus and the U.S. Census Bureau's TIGER/Line Files. The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

  9. Exploring the basin of attraction for flow and residence time responses in a small catchment

    NASA Astrophysics Data System (ADS)

    Beven, Keith; Davies, Jess

    2015-04-01

    The Multiple Interacting Pathways (MIPs) particle tracking model was first applied at the basin scale to the data set collected by Allan Rodhe and colleagues at the small Grdsjn catchment in Sweden. It was shown to reproduce flow and tracer data at both plot and catchment scales reasonable well. The implication was that the model could reproduce both the distribution of flow velocities and the celerity responses in the catchment. This allows it then to be used in an exploration of the state space of the modelled catchment, with the advantage that the boundary conditions are known precisely and every particle of water is accounted for (a limitation of using observational data sets for this purpose). The exploration of both discharges and nonstationary residence time information is made on a relatively long model run of 20 years of available data. The results demonstrate quite clearly the hysteresis in flow and residence times that results from differences in velocities and celerities. In such a forced system, of course, there is always with potential for a new, more extreme, response to lie outside the range of past behaviours and this is seen as multiple outliers in the phase space plots. There is some evidence that the time series have the characteristics of fractal processes but there is no clear structure within the main region of behaviour. This basin model, at least, is just endlessly variable within the domain defined by the pattern of inputs.

  10. Nonstationarities in Catchment Response According to Basin and Rainfall Characteristics: Application to Korean Watershed

    NASA Astrophysics Data System (ADS)

    Kwon, Hyun-Han; Kim, Jin-Guk; Jung, Il-Won

    2015-04-01

    It must be acknowledged that application of rainfall-runoff models to simulate rainfall-runoff processes are successful in gauged watershed. However, there still remain some issues that will need to be further discussed. In particular, the quantitive representation of nonstationarity issue in basin response (e.g. concentration time, storage coefficient and roughness) along with ungauged watershed needs to be studied. In this regard, this study aims to investigate nonstationarity in basin response so as to potentially provide useful information in simulating runoff processes in ungauged watershed. For this purpose, HEC-1 rainfall-runoff model was mainly utilized. In addition, this study combined HEC-1 model with Bayesian statistical model to estimate uncertainty of the parameters which is called Bayesian HEC-1 (BHEC-1). The proposed rainfall-runofall model is applied to various catchments along with various rainfall patterns to understand nonstationarities in catchment response. Further discussion about the nonstationarity in catchment response and possible regionalization of the parameters for ungauged watershed are discussed. KEYWORDS: Nonstationary, Catchment response, Uncertainty, Bayesian Acknowledgement This research was supported by a Grant (13SCIPA01) from Smart Civil Infrastructure Research Program funded by the Ministry of Land, Infrastructure and Transport (MOLIT) of Korea government and the Korea Agency for Infrastructure Technology Advancement (KAIA).

  11. Catchment condition as a major control on the quality of receiving basin sediments (Sydney Harbour, Australia).

    PubMed

    Birch, G F; McCready, S

    2009-04-01

    The current work aimed to compile existing information to better understand the source, fate and effects of metallic contaminants in one catchment-receiving basin system (Iron Cove) in Sydney Harbour (Australia). Copper, Pb and Zn concentrations of potential source materials, i.e. soils (mean 62, 410 and 340 microg g(-1), respectively) and road dust (mean 160, 490 and 520 microg g(-1), respectively) and in materials being transported to the estuary, i.e. in gully pots (mean 110, 200 and 260 microg g(-1) for Cu, Pb, and Zn, respectively), in bedload (mean 210, 880 and 1700 microg g(-1), respectively) and particulates in canals draining the catchment (mean 325, 290 and 1865 microg g(-1), respectively) were highly enriched. Estuarine sediments in the receiving basin are enriched 20 times over pre-anthropogenic concentrations and are toxic to benthic animals at the canal mouths. Stormwater remediation is required to reduce metal loads to the adjacent estuary. PMID:19211135

  12. A participatory approach for Integrated River Basin Management in the Elbe catchment

    NASA Astrophysics Data System (ADS)

    Nunneri, C.; Hofmann, J.

    2005-02-01

    This paper presents a qualitative analysis of a series of in-depth interviews with governmental and non-governmental institutions (NGOs). Within the EUROCAT 1 project this methodology of participatory approach, aiming to scope the present perceptions about environmental issues and possible strategies for environmental improvement, is applied to the study of the Elbe catchment for the first time. In this frame, an Advisory Board (AB) was created, with the aim of giving insights into conflicting interests in the river catchment and guidelines for river basin management. Focus of the Elbe case study is the issue of nutrient enrichment (from the catchment) and the induced eutrophication of the coastal waters (the German Bight). Specifically, regarding this topic, the possible reduction of eutrophication in the German Bight by a (policy driven) decrease in nutrient inputs from the catchment area is analysed. Different measures for reducing the input of nutrients from the catchment, and ultimately preventing eutrophication of the coastal waters are considered. In this context, the members of the AB were asked about the efficiency and feasibility of different measures and the criteria for choosing 'better' management solutions among the possible ones. Although there is a general agreement about the necessity of reducing nutrient emissions, some members of the AB perceive other environmental issues (e.g. altered morphodynamics) as more relevant than nutrient enrichment. Voluntary cooperation, eco-efficiency and 'trans-sectoral' communication are the key concepts mentioned as being indispensable for integrated management. The (public) acceptance of measures for nutrient reduction have to find its way through compromises and social equity, allowing for win-win solutions among different groups of interests and balanced spatial division of costs and benefits. EUROpean CATchments, Project N EVK1-CT-2000-00044 ( http://www.iia-cnr.unical.it/EUROCAT/project.htm).

  13. View of former preliminary sedimentation basin, looking east from south ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of former preliminary sedimentation basin, looking east from south side of low-lift pumping station. - Robert B. Morse Water Filtration Plant, 10700 and 10701 Columbia Pike, Silver Spring, Montgomery County, MD

  14. Role of river bank erosion in sediment budgets of catchments within the Loire river basin (France)

    NASA Astrophysics Data System (ADS)

    Gay, Aurore; Cerdan, Olivier; Poisvert, Cecile; Landemaine, Valentin

    2014-05-01

    Quantifying volumes of sediments produced on hillslopes or in channels and transported or stored within river systems is necessary to establish sediment budgets. If research efforts on hillslope erosion processes have led to a relatively good understanding and quantification of local sources, in-channel processes remain poorly understood and quasi inexistent in global budgets. However, profound landuse changes and agricultural practices have altered river functioning, caused river bank instability and stream incision. During the past decades in France, river channelization has been perfomed extensively to allow for new agricultural practices to take place. Starting from a recent study on the quantification of sediment fluxes for catchments within the Loire river basin (Gay et al. 2013), our aim is to complete sediment budgets by taking into account various sources and sinks both on hillslope and within channel. The emphasis of this study is on river bank erosion and how bank erosion contributes to global budgets. A model of bank retreat is developed for the entire Loire river basin. In general, our results show that bank retreat is on average quite low with approximately 1 cm.yr-1. However, a strong variability exists within the study area with channels displaying values of bank retreat up to ~10 cm.yr-1. Our results corroborate those found by Landemaine et al. in 2013 on a small agricultural catchment. From this first step, quantification of volumes of sediment eroded from banks and available for transport should be calculated and integrated in sediment budgets to allow for a better understanding of basin functioning. Gay A., Cerdan O., Delmas M., Desmet M., Variability of sediment yields in the Loire river basin (France): the role of small scale catchments (under review). Landemaine V., Gay A., Cerdan O., Salvador-Blanes S., Rodriguez S. Recent morphological evolution of a headwater stream in agricultural context after channelization in the Ligoire river (France) (in prep)

  15. Catchment Restoration in the Tweed UNESCO-IHP HELP Basin - Eddleston Water

    NASA Astrophysics Data System (ADS)

    Spray, Christopher

    2013-04-01

    The EU Water Frame Work Directive (WFD) requires member states to work towards the achievement of 'good ecological status' for water bodies, through a 6 year cycle of river basin management plans (RBMPs). Within these RBMPs, states must develop and implement programmes of measures designed to improve the quality of individual water bodies at risk of failing to achieve this status. These RBMPS must not only be focussed on the key causes of failure, but increasingly look to deliver multiple benefits, such as flood risk reduction and improvement to biodiversity from such catchment interventions, and to involve communities and other stakeholders in restoration of their local environment. This paper reports on progress of a detailed study of the restoration of the Eddleston Water, a typical 'failing' water body in Scotland, the monitoring and governance arrangements behind this, and implications for rehabilitation of river systems elsewhere. Within UK rivers, the main causes of failure to achieve good ecological status are historical morphological changes to river courses, diffuse agricultural pollution and invasive non-native species. The Eddleston Water is a 70 sq kms sub-catchment of the Tweed, an UNESCO IHP-HELP basin in the Scottish : English borders, and is currently classified as 'bad' status, due largely to morphological changes to the course and structure of the river over the past 200 years. The main challenge therefor is physical restoration of the river to achieve functional connectivity with the flood plain. At the same time however, the two communities within the catchment suffer from flooding, so a second priority is to intervene within the catchment to reduce the risk of flooding through the use of "natural flood management" measures and, underlying both these two aspects a whole catchment approach to community participation and the achievement of a range of other ecosystem service benefits, including conservation of biodiversity. We report on the initial characterisation of the catchment; the identification of potential key locations and types of intervention to improve ecological status and flood risk reduction; the setting up of the monitoring networks, the engagement with local communities and land managers; initial habitat modifications and the early results of the study. We situate this within the wider context of priorities for restoration and the UNESCO IHP-HELP programme.

  16. An appraisal of precipitation distribution in the high-altitude catchments of the Indus basin.

    PubMed

    Dahri, Zakir Hussain; Ludwig, Fulco; Moors, Eddy; Ahmad, Bashir; Khan, Asif; Kabat, Pavel

    2016-04-01

    Scarcity of in-situ observations coupled with high orographic influences has prevented a comprehensive assessment of precipitation distribution in the high-altitude catchments of Indus basin. Available data are generally fragmented and scattered with different organizations and mostly cover the valleys. Here, we combine most of the available station data with the indirect precipitation estimates at the accumulation zones of major glaciers to analyse altitudinal dependency of precipitation in the high-altitude Indus basin. The available observations signified the importance of orography in each sub-hydrological basin but could not infer an accurate distribution of precipitation with altitude. We used Kriging with External Drift (KED) interpolation scheme with elevation as a predictor to appraise spatiotemporal distribution of mean monthly, seasonal and annual precipitation for the period of 1998-2012. The KED-based annual precipitation estimates are verified by the corresponding basin-wide observed specific runoffs, which show good agreement. In contrast to earlier studies, our estimates reveal substantially higher precipitation in most of the sub-basins indicating two distinct rainfall maxima; 1st along southern and lower most slopes of Chenab, Jhelum, Indus main and Swat basins, and 2nd around north-west corner of Shyok basin in the central Karakoram. The study demonstrated that the selected gridded precipitation products covering this region are prone to significant errors. In terms of quantitative estimates, ERA-Interim is relatively close to the observations followed by WFDEI and TRMM, while APHRODITE gives highly underestimated precipitation estimates in the study area. Basin-wide seasonal and annual correction factors introduced for each gridded dataset can be useful for lumped hydrological modelling studies, while the estimated precipitation distribution can serve as a basis for bias correction of any gridded precipitation products for the study area. PMID:26802357

  17. Determining Spatial Distribution And Air-Water Exchange Of Polycyclic Aromatic Hydrocarbons In Stormwater Runoff Catchment Basins

    NASA Astrophysics Data System (ADS)

    Kasaraneni, V. K.; Schifman, L. A.; Craver, V.; Boving, T. B.

    2014-12-01

    Stormwater runoff is a conduit for several pollutants such as polycyclic aromatic hydrocarbons (PAHs) in to surface and ground water bodies. The control of runoff and pollutants is typically addressed by best management practices (BMPs), such as retention/detention ponds or catchment basins in general. The effectiveness of catchment basins in reducing the volume of runoff and removal of some contaminants has been established. However, very little is known about the fate of the contaminants settled within these structures. In coastal regions and places with shallow groundwater tables accumulation of high concentrations of PAHs in the bottom sediments poses a potential threat for groundwater contamination. The concentrations of PAHs accumulated in the sediments of these catchment basins will primarily depend on the sources of runoff origin and the surrounding land use. Due to the physico-chemical characteristics of PAHs, their transport not only can occur in the liquid and solid phase, but it is also possible that gaseous emissions can be produced from BMP systems. For the purpose of this study, five stormwater catchment basins along the I-95 corridor in Rhode Island were selected based on the stormwater runoff origin and covering (industrial, urban, highway, and commercial) land uses. To study the stratification of PAHs sediment cores one foot were collected and analyzed for 31PAHs (16 EPA parent PAH and 15 methylated PAHs). In order to determine whether the catchment basins are a source of atmospheric pollution polyethylene passive samplers were deployed to determine the freely dissolved PAHs in the water column and gas phase PAHs at the air-water interface. This presentation will describe how PAH fluxes move between three environmental compartments (sediments, water column, atmosphere) within the five stormwater catchment basins. Further, it will be investigated whether these BMP structures can act as contaminant sources rather than sinks and whether BMP maintenance has to be targeted towards pollutant removal to maintain an effective stormwater treatment system.

  18. Estimation of Catchment Transit Time in Fuji River Basin by using an improved Tank model

    NASA Astrophysics Data System (ADS)

    Wenchao, M.; Yamanaka, T.; Wakiyama, Y.; Wang, P.

    2013-12-01

    As an important parameter that reflects the characteristics of catchments, the catchment transit time (CTT) has been given much more widely attentions especially in recent years. The CTT is defined as the time water spends travelling through a catchment to the stream network [1], and it describes how catchments retain and release water and solutes and thus control geochemical and biogeochemical cycling and contamination persistence [2]. The objectives of the present study are to develop a new approach for estimating CTT without prior information on such TTD functions and to apply it to the Fuji River basin in the Central Japan Alps Region. In this study, an improved Tank model was used to compute mean CTT and TTD functions simultaneously. It involved water fluxes and isotope mass balance. Water storage capacity in the catchment, which strongly affects CTT, is reflected in isotope mass balance more sensitively than in water fluxes. A model calibrated with observed discharge and isotope data is used for virtual age tracer computation to estimate CTT. This model does not only consider the hydrological data and physical process of the research area but also reflects the actual TTD with considering the geological condition, land use and the other catchment-hydrological conditions. For the calibration of the model, we used river discharge record obtained by the Ministry of Land, Infrastructure and Transportation, and are collecting isotope data of precipitation and river waters monthly or semi-weekly. Three sub-catchments (SC1~SC3) in the Fuji River basin was selected to test the model with five layers: the surface layer, upper-soil layer, lower-soil layer, groundwater aquifer layer and bedrock layer (Layer 1- Layer 5). The evaluation of the model output was assessed using Nash-Sutcliffe efficiency (NSE), root mean square error-observations standard deviation ratio (RSR), and percent bias (PBIAS). Using long time-series of discharge records for calibration, the simulated discharge basically satisfied requirements of reproducing water fluxes and their balance, while improvements in parameter estimations relating to isotope mass balance is necessary. Water balance and isotopes balance have been exercised in abundant simulations by using Mont-Carlo method, and the optimal parameters combination generated reliable result. Later, we figured out the temporal-variant MTT as well as the degree of influence that brought by precipitation event, where the results showed inverse relationship between precipitation amount and MTT value. Reference: [1] Jeffrey. J. McDonnell, Kevin J. McGuire, Aggarwal, P., et al. 2010. How old is stream water? Open questions in catchment transit time conceptualization, modeling and analysis. Hydro. Process. 24, 1745-1754. [2] Kevin J. McGuire, Jeffrey J. McDonnell. 2006. A review and evaluation of transit time modeling. Journal of Hydrology. 330, 543-563.

  19. Continuous simulation modelling for design flood estimation in South Africa: Preliminary investigations in the Thukela catchment

    NASA Astrophysics Data System (ADS)

    Chetty, Kershani; Smithers, Jeff

    Several recent literature reviews highlight the need for improvements in procedures for design flood estimation [Cordery, I., Pilgrim, D.H., 2000. The state of the art of flood prediction. In: Parker, D.J. (Ed.), Floods. vol. II. Routledge, London, UK, pp. 185-197; Smithers, J.C., Schulze, R.E., 2001. Design runoff estimation: a review with references to practices in South Africa. In: Tenth South African National Hydrological Symposium. SANCIAHS, Pietermaritzburg, RSA]. In general, these reviews indicate that internationally the trend is to adopt a continuous simulation modeling approach for design flood estimation. The continuous simulation modelling (CSM) approach to design flood estimation has many advantages and has the potential to overcome many of the limitations of the often used design event approach. A pilot study into the development of a continuous simulation modelling system for design flood estimation is being undertaken in the Thukela catchment in South Africa. Preliminary studies using the ACRU agrohydrological modelling system are detailed in this paper and include investigations into the appropriate scale and levels of soil and land cover information required for use in a CSM approach for design flood estimation. Results indicate that CSM with the ACRU model requires quaternary catchments to be further divided into sub-quaternary catchments, and that using area weighted soils and land cover information gives better results than using modal soils information or single dominant soil or land cover information.

  20. Preliminary design review report for K Basin Dose Reduction Project

    SciTech Connect

    Blackburn, L.D.

    1996-01-01

    The strategy for reducing radiation dose, originating from radionuclides absorbed in the K East Basin concrete, is to raise the pool water level to provide additional shielding. This report documents a preliminary design review conducted to ensure that design approaches for cleaning/coating basin walls and modifying other basin components were appropriate. The conclusion of this review was that design documents presently conclusion of this review was that design documents presently completed or in process of modification are and acceptable basis for proceeding to complete the design.

  1. Ecosystem based river basin management planning in critical water catchment in Mongolia

    NASA Astrophysics Data System (ADS)

    Tugjamba, Navchaa; Sereeter, Erdenetuul; Gonchigjav, Sarantuya

    2014-05-01

    Developing the ecosystem based adaptation strategies to maintain water security in critical water catchments in Mongolia would be very significant. It will be base by reducing the vulnerability. "Ecosystem Based adaptation" is quite a new term in Mongolia and the ecosystem approach is a strategy for the integrated management of land, water and living resources that promotes conservation and sustainable use in an equitable way. To strengthen equitable economic development, food security, climate resilience and protection of the environment, the implementation of sustainable river basin management in critical water catchments is challenging in Mongolia. The Ulz river basin is considered one of the critical water catchments due to the temperature has increased by in average 1.30 over the period 1976 to 2011. It is more intense than the global warming rate (0.740C/100 years) and a bit higher than the warming rate over whole Mongolia as well. From long-term observations and measurements it is clear that Ulz River has low water in a period of 1970-1980 and since the end of 1980s and middle of 1990s there were dominated years of the flood. However, under the influence of the global warming, climate changes of Mongolia and continuation of drought years with low water since the end of 1990s until today river water was sharply fallen and dried up. For the last ten years rivers are dried up and annual mean run-off is less by 3-5 times from long term mean value. The Ulz is the transboundary river basin and taking its origin from Ikh and Baga Burd springs on territory of Norovlin soum of Khentii province that flows through Khentii and Dornod provinces to the northeast, crossing the state border it flows in Baruun Tari located in Tari Lake concavity in Russia. Based on the integrative baseline study on the 'The Ulz River Basin Environmental and Socioeconomic condition', ecosystem based river basin management was planned. 'Water demand Calculator 3' (WDC) software was used to estimate water demand and calculate water use balance in 2015, 2021. The result of the water balance estimation shows that water consumption-use will be increased 3 times in the river basin by 2021. As the water consumption-use source, surface water - 6.4 % and groundwater is 93.6 percent. The current consumption of the mining sector is shares 71 percent of the total users; it would be 82 percent in 2021. However, the livestock water consumption-use is 27 percent of the current demand; it would be decrease up to 16 percent in 2021. Ecosystem based approach IWRM plan would be efficient to the local resident to adapt the climate change situation. Thus, the results of the research study on the river basin ecosystem services and values are the base of the planning.

  2. Monitoring of metals, organic compounds and coliforms in water catchment points from the Sinos River basin.

    PubMed

    Nascimento, C A; Staggemeier, R; Bianchi, E; Rodrigues, M T; Fabres, R; Soliman, M C; Bortoluzzi, M; Luz, R B; Heinzelmann, L S; Santos, E L; Fleck, J D; Spilki, F R

    2015-05-01

    Unplanned use and occupation of the land without respecting its capacity of assimilation and environmental purification leads to the degradation of the environment and of water used for human consumption. Agricultural areas, industrial plants and urban centres developed without planning and the control of effluent discharges are the main causes of water pollution in river basins that receive all the liquid effluents produced in those places. Over the last decades, environmental management has become part of governmental agendas in search of solutions for the preservation of water quality and the restoration of already degraded resources. This study evaluated the conditions of the main watercourse of the Sinos River basin by monitoring the main physical, chemical and microbiological parameters described in the CONAMA Resolution no. 357/2005.The set of parameters evaluated at five catchment points of water human consumption revealed a river that has different characteristics in each reach, as the upper reach was class 1, whereas the middle and lower reaches of the basin were class 4. Monitoring pointed to households as the main sources of pollutants in those reaches, although metals used in the industrial production of the region were found in the samples analyzed. PMID:26270213

  3. Analysis of annual dissolved-solids loading from selected natural and irrigated catchments in the Upper Colorado River Basin, 1974-2003

    USGS Publications Warehouse

    Kenney, Terry A.; Gerner, Steven J.; Buto, Susan G.

    2012-01-01

    Dissolved-solids loading from 17 natural catchments and 14 irrigated catchments in the Upper Colorado River Basin was examined for the period from 1974 through 2003. In general, dissolved-solids loading increased and decreased concurrently in natural and irrigated catchments but at different magnitudes. Annually, the magnitude of loading in natural catchments changed about 10 percent more, on average, than in irrigated catchments. Measures of variability, or spread, indicate that natural catchments had 35 percent greater annual variability in loading than irrigated catchments. Precipitation and dissolved-solids loads were positively correlated in natural catchments, and a weak positive correlation was determined for irrigated catchments. A weak negative correlation between temperature and dissolved-solids load was determined for both natural and irrigated catchments. In irrigated catchments, the dissolved-solids load response to an above-average precipitation period from 1982 through 1987 generally lagged behind that in the natural catchments. On average, irrigated catchments with reservoir storage had the largest normalized maximum annual loads during the wet period.

  4. The 20th century whole-basin trophic history of an inter-drumlin lake in an agricultural catchment.

    PubMed

    Jordan, Philip; Rippey, Brian; Anderson, N John

    2002-10-01

    Eight 1-m sediment cores were extracted from across the basin of Friary Lough, a 5.4-ha eutrophic lake in a wholly grassland agricultural catchment in Co. Tyrone, Northern Ireland. Sedimentary TP, diatom inferred TP, Ca, Na, Fe, Mn, loss-on-ignition (LOI), dry weight and density were determined in the core profiles. Core dating and correlation gave a 210Pb, 137Cs and 241Am chronology from 1906 to 1995 and enabled a whole-basin estimate of chemical and sediment accumulation rate over the 20th Century. The major changes for all parameters occurred after c. 1946. Sediment accumulation rate was most influenced by organic matter accumulations, probably of planktonic origin, and increasing after c. 1946. Inorganic sediment accumulation rate was found to be largely unchanging through the century at 10 t km(-2) yr(-1) when expressed as catchment exports. All chemical accumulation rate changes occurred after c. 1946. Total phosphorus accumulation rate, however, was found to be the only chemical to be increasing throughout the epilimnion and hypolimnion areas of the sedimentary basin at an average of 22.5 mg m(-2) yr(-1) between 1946 and 1995. The other chemical parameters showed increasing accumulation rates after c. 1946 in the epilimnion part of the basin only. Interpreted in terms of whole-basin sedimentation and catchment export processes over time, it is suggested that diffuse TP inputs are independent of sediment inputs. This corresponds to hydrochemical models that suggest soluble P as the primary fraction that is lost from grassland catchments. The increase in sedimentary TP accumulation rate, and DI-TP concentration, are also explained with regard to current models that suggest increases in runoff P concentrations from elevated soil P concentrations. Increases in eplimnion chemical and sediment accumulation rate after c. 1946 may be due to local erosion that has limited impact on lake basin sedimentation. PMID:12389788

  5. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Bedrock Geology

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the area of bedrock geology types in square meters compiled for every catchment of MRB_E2RF1 catchments for Major River Basins (MRBs, Crawford and others, 2006). The source data set is the "Geology of the Conterminous United States at 1:2,500,000 Scale--A Digital Representation of the 1974 P.B. King and H.M. Beikman Map" (Schuben and others, 1994). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  6. Data mining methods for predicting event runoff coefficients in ungauged basins using static and dynamic catchment characteristics

    NASA Astrophysics Data System (ADS)

    Loritz, Ralf; Weiler, Markus; Seibert, Simon

    2015-04-01

    Transferring hydrological information into ungauged basin by regionalisation approaches is an ongoing field of research. Usually regionalisation techniques use physical landscape descriptors to transfer either model parameters or hydrological characteristics from a catchment to another. A common problem of these approaches is the high degree of uncertainty associated to their results. One reason is that often solely static (structural) catchment characteristics such as catchment area, physiographic properties or land use data are used for regionalisation. However, it is well known that the hydrological response of a 'natural' system is a complex and a non-linear interaction of its structure, state and forcing. Here it is important to note, that only structure is a static property. State and forcing are highly dynamic when considering the temporal and spatial scale of a rainfall-runoff event. To overcome the limitations associated with 'static' regionalisation techniques we propose a regionalisation technique for event runoff coefficients combining static and dynamic catchment properties. The approach is based on the two data mining algorithms 'random forests' and 'quantile regression forests'. The static catchment characteristics include standard variables such as physiographic properties, land cover and soil data. The dynamic variables include event based properties of the forcing (i.e. rainfall amount, intensity,...) and proxies for the initial state of the catchment (i.e. initial soil moisture). Together with the runoff coefficient these quantities were extracted form hydro-meteorological time series (precipitation, discharge and soil moisture) using an automated rainfall-runoff event detection technique. We tested our method using a set of 60 meso-scale catchments (3.1 to 205,6 km2, covering a range of different geologies and land uses) from Southwest Germany. We randomly separated the catchments in two groups. The first group (30 donor catchments) was used to train the data mining models . Based on the resulting relations we then predicted event runoff coefficients for the other half of the catchments (30 test catchments). With this regression method we are able to predict event runoff coefficient s in the test group with an overall root mean square error of about 5%. Furthermore our approach indicates that the dynamic characteristics (event precipitation and initial soil moisture) had a much higher importance for the prediction of event runoff coefficients than the static properties. In the next step, we applied random forest regressions to all 60 catchments individually based on the extracted event variables. The relative importance of the predictor variables of each of these regressions can be interpreted as indicators for the dominating rainfall- runoff controls within the basins (e.g. to identify initial storage or rainfall intensity controlled conditions). We conclude that the ensemble regression tree methods provide insights into the 'functioning' of the individual catchments and that dynamic catchment properties (observed on meaningful spatial and temporal scales) have a very high potential for prediction hydrological functions in ungauged catchments.

  7. Plantation Forestry and Peak Flow Responses in Experimental Catchments and Large River Basins in Chile

    NASA Astrophysics Data System (ADS)

    Iroume, A.; Huber, A.

    2007-05-01

    Land use changes are inextricably linked to water resources and the consequences of such changes are a problem faced by water managers and governments across the world. This particular study considers the impact of changes in plantation forest cover on the hydrological response, with a specific focus on the issue of peak flow conditions and variation. The research still in progress is focused in small catchments and large river basins of Chile. The analysis of the data and the preparation of this document were carried out within the framework of the INCO- CT2004-510739 EPIC FORCE Project. EPIC FORCE aims to improve the integrated management of forest and water resources at the river basin scale through the development of policies based on sound science, focusing on extreme rainfall/snowmelt events. The focus areas are four Latin American countries (Costa Rica, Ecuador, Chile and Argentina.), which represent a range of humid forest and rainfall/snowmelt regimes with major flood and erosion problems and which suffer from a lack of integrated water and forest policies. Much of the controversy surrounding changes in peak flows following forest treatment arises from uncertainty over the response from different sizes of storms; whilst most studies agree that mean peak flow generally increases (even for only a short period) in the post harvesting period, there have been a number of different conclusions regarding influence of forest cover on peak flows from small storms compared with the flows from large events. In Chile, this research is been carried out in experimental catchments (less than 1 km2) and in large river basins (greater than 94 and up to 1,545 km2). Results from La Reina (34.4 ha), where peak flows from the pre-harvesting period (years 1997 to 1999, plantation of Pinus radiata established in 1977 covering the 79.5% of the area) were compared with those from the post- harvesting period (plantation clearcut between end of 1999 and first months of 2000 and replaced by an Eucalyptus nitens plantation) show that in average peak flows increased by 32% after forest removal. Analyzing pre and post-harvesting peak flows from different sizes of rainfall events (rainfall "small" events from 5 to 10 mm, "medium" events from 10 to 50 mm, and "large" events greater than 50 mm), the median of the peak flows increased by 67% for the small events and 32% for the large events. Besides, comparing the pre-harvesting condition with each of the years of the post-harvesting period (years 2000 to 2005), the analysis showed that in all cases post-harvesting peak flows were still significantly higher than before forest clearing. Decreases in annual runoff were noticed in the large river basins where forested area almost doubled between the beginnings of the 1970 up to present. These decreases in annual runoff are well explained by the increases in evapotranspiration capacity of the new planted forests, calculated using the Zhang model and through direct measurements done in experimental plots by the authors. However, the increases in planted area within these large river basins seem not to affect peak flows, as peak flows from the "pre plantation development period" were not statistically different from those of the "post plantation development" one. This research is allowing the generation of evidence based management proposals to support forest certification processes of Chilean companies.

  8. Geo-referenced modelling of metal concentrations in river basins at the catchment scale

    NASA Astrophysics Data System (ADS)

    Hffmeyer, N.; Berlekamp, J.; Klasmeier, J.

    2009-04-01

    1. Introduction The European Water Framework Directive demands the good ecological and chemical state of surface waters [1]. This implies the reduction of unwanted metal concentrations in surface waters. To define reasonable environmental target values and to develop promising mitigation strategies a detailed exposure assessment is required. This includes the identification of emission sources and the evaluation of their effect on local and regional surface water concentrations. Point source emissions via municipal or industrial wastewater that collect metal loads from a wide variety of applications and products are important anthropogenic pathways into receiving waters. Natural background and historical influences from ore-mining activities may be another important factor. Non-point emissions occur via surface runoff and erosion from drained land area. Besides deposition metals can be deposited by fertilizer application or the use of metal products such as wires or metal fences. Surface water concentrations vary according to the emission strength of sources located nearby and upstream of the considered location. A direct link between specific emission sources and pathways on the one hand and observed concentrations can hardly be established by monitoring alone. Geo-referenced models such as GREAT-ER (Geo-referenced Regional Exposure Assessment Tool for European Rivers) deliver spatially resolved concentrations in a whole river basin and allow for evaluating the causal relationship between specific emissions and resulting concentrations. This study summarizes the results of investigations for the metals zinc and copper in three German catchments. 2. The model GREAT-ER The geo-referenced model GREAT-ER has originally been developed to simulate and assess chemical burden of European river systems from multiple emission sources [2]. Emission loads from private households and rainwater runoff are individually estimated based on average consumption figures, runoff rates and the site-specific population and surface area (roof, gutter, street) connected to the local sewer system. For emissions from industry and mine drainage quantitative data on average annual loads are collected. WWTP effluent loads additionally consider average removal during wastewater treatment. Runoff from non-point sources such as agricultural areas and unsealed soils is estimated from average wash-off rates per area multiplied with the total area drained into a specified river reach of the river system. Groundwater infiltration is considered in quantities equal to the base flow in the respective river stretch. The model simulates the steady-state concentration distribution in the whole river basin considering transport and removal processes in the river system. The only major removal process for metals in surface water is sedimentation. Simulations have been carried out exemplary for zinc and copper in the German river basins Main (27,292 km2), Ruhr (4,485 km2) and Sieg (2,832 km2). 3. Results and discussion Model estimations of effluent loads for selected WWTPs agreed well with available surveillance data so that the emission module outcome can be assumed as appropriate starting point for surface water modeling. A detailed comparison of simulated surface water concentrations with monitoring data was performed for zinc in the Ruhr river basin. Good agreement between monitoring data and model simulations was achieved at 20 monitoring sites in the Ruhr River and its major tributaries. GREAT-ER was able to simulate zinc concentrations in surface waters based on estimation of loads from several emission sources and via different emission pathways. A wide applicability of the model was corroborated by successful simulations of zinc concentrations in the Main river basin and simulations for copper in both catchments. The functionality of the model allows for running scenarios with different emission assumptions that can be easily compared. Such case studies can be used to demonstrate the effect of specific mitigation strategies such as improved treatment of ra

  9. Source rock potential of Nanpanjiang, Basin, south China - preliminary report

    SciTech Connect

    Parrish, J.T.; Zhongrui, S.; Yirong, Z.; Wenhai, H.

    1986-05-01

    The Nanpanjiang basin of south China occupies 100,000 km/sup 2/ in southern Guizhou and eastern Yunnan Provinces and northwestern Guangxi autonomous region. The basin contains primarily Paleozoic and Triassic rocks. As yet, no producible hydrocarbons have been found in Nanpanjiang basin, although oil seeps exist in margins of the basin and producing wells are present in adjacent basins. The authors analyzed Ordovician through Permian carbonate rocks and Cambrian through Triassic clastic rocks from within the margins of the Nanpanjiang basin for total organic carbon (TOC), vitrinite reflectance, and extractable hydrocarbon (HC) content and composition. TOC values ranged from 0.02 to 3.91%, total HC (S/sub 1/ and S/sub 2/) ranged from 0.004 to 0.1 mg/g (S/sub 1/:0.003-0.048; S/sub 2/: < 0.003-0.07), and vitrinite reflectance values were mostly above 1.0%. permian carbonates throughout the basin contain solid bitumen in cavities and fractures; the one available sample of this solid bitumen contained no chloroform-soluble bitumen. Their preliminary conclusion is that hydrocarbons have been generated but not preserved because the basin is now thermally overmature. This conclusion is supported by fluid inclusion studies and by the conodont alteration index, which ranges from 3 to 5, both of which indicate high temperatures. Generated liquid hydrocarbons may be represented by the solid bitumen in the Permian carbonates; the presence of gas is not ruled out by the geochemical evidence.

  10. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Physiographic Provinces

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the area of each physiographic province (Fenneman and Johnson, 1946) in square meters, compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data are from Fenneman and Johnson's Physiographic Provinces of the United States, which is based on 8 major divisions, 25 provinces, and 86 sections representing distinctive areas having common topography, rock type and structure, and geologic and geomorphic history (Fenneman and Johnson, 1946).The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  11. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Surficial Geology

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the area of surficial geology types in square meters compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data set is the "Digital data set describing surficial geology in the conterminous US" (Clawges and Price, 1999).The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2008). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  12. Attributes for MRB_E2RF1 Catchments in Selected Major River Basins: Population Density, 2000

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This data set represents the average population density, in number of people per square kilometer multiplied by 10 for the year 2000, compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data set is the 2000 Population Density by Block Group for the Conterminous United States (Hitt, 2003). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  13. Sulfonylurea herbicides in an agricultural catchment basin and its adjacent wetland in the St. Lawrence River basin.

    PubMed

    de Lafontaine, Yves; Beauvais, Conrad; Cessna, Allan J; Gagnon, Pierre; Hudon, Christiane; Poissant, Laurier

    2014-05-01

    The use of sulfonylurea herbicides (SU) has increased greater than 100 times over the past 30 years in both Europe and North America. Applied at low rates, their presence, persistence and potential impacts on aquatic ecosystems remain poorly studied. During late-spring to early fall in 2009-2011, concentrations of 9 SU were assessed in two agricultural streams and their receiving wetland, an enlargement of the St. Lawrence River (Canada). Six SU in concentrations >LOQ (10 ng L(-1)) were detected in 10% or less of surface water samples. Rimsulfuron was detected each year, sulfosulfuron and nicosulfuron in two years and the others in one year only, suggesting that application of specific herbicides varied locally between years. Detection frequency and concentrations of SU were not significantly associated with total precipitation which occurred 1 to 5d before sampling. Concentrations and fate of SU differed among sites due to differences in stream dynamics and water quality characteristics. The persistence of SU in catchment basin streams reflected the dissipation effects associated with stream discharge. Maximum concentrations of some SU (223 and 148 ng L(-1)) were occasionally above the baseline level (100 ng L(-1)) for aquatic plant toxicity, implying potential toxic stress to flora in the streams. Substantially lower concentrations (max 55 ng L(-1)) of SU were noted at the downstream wetland site, likely as a result from dilution and mixing with St. Lawrence River water, and represent less toxicological risk to the wetland flora. Sporadic occurrence of SU at low concentrations in air and rain samples indicated that atmospheric deposition was not an important source of herbicides to the study area. PMID:24534695

  14. Validation of a simple distributed sediment delivery approach in selected sub-basins of the River Inn catchment area

    NASA Astrophysics Data System (ADS)

    Reid, Lucas; Kittlaus, Steffen; Scherer, Ulrike

    2015-04-01

    For large areas without highly detailed data the empirical Universal Soil Loss Equation (USLE) is widely used to quantify soil loss. The problem though is usually the quantification of actual sediment influx into the rivers. As the USLE provides long-term mean soil loss rates, it is often combined with spatially lumped models to estimate the sediment delivery ratio (SDR). But it gets difficult with spatially lumped approaches in large catchment areas where the geographical properties have a wide variance. In this study we developed a simple but spatially distributed approach to quantify the sediment delivery ratio by considering the characteristics of the flow paths in the catchments. The sediment delivery ratio was determined using an empirical approach considering the slope, morphology and land use properties along the flow path as an estimation of travel time of the eroded particles. The model was tested against suspended solids measurements in selected sub-basins of the River Inn catchment area in Germany and Austria, ranging from the high alpine south to the Molasse basin in the northern part.

  15. Fine-Resolution Hydrologic Modeling of Semiarid River Basins: Preliminary Results from the Upper Rio Grande

    NASA Astrophysics Data System (ADS)

    Wyckoff, R.; Vivoni, E. R.; Rinehart, A.

    2004-12-01

    Water resources management and decision making in arid and semiarid regions require scientific knowledge and predictive capability of the physical processes occurring within hydrologic systems at scales sufficient to capture the variability inherent in the resource and its utilization. Our understanding of the interaction between water supply and demand is aided through numerical models that best represent our current knowledge of the hydrologic, ecological and meteorological processes in river basins. To this end, advances in distributed hydrologic modeling over large regional watersheds can aid in providing estimates of water availability and its susceptibility to climate variations, land-cover change and population growth. In this study, we utilize the TIN-based Real-time Integrated Basin Simulator (tRIBS) model to simulate continuous hydrological processes within subbasins of the Upper Ro Grande in north-central New Mexico. First, we introduce the distributed model by highlighting the following salient features: (1) coupled unsaturated and saturated zones through a dynamic water table, (2) coupled energy and hydrologic balance at the land surface and (3) topographically-driven soil moisture redistribution, radiation and evapotranspiration. Accurate terrain representation at fine-resolution is achieved through the use of a triangulated irregular network (TIN) terrain model. Second, we present semiarid case studies in model setup, parameterization and continuous operation for the Upper Ro Puerco and Jemez River. These river basins provide test cases for the calibration and validation of the tRIBS model through the use of in-situ measurement networks and long-term rainfall and stream gauging records. We will present the catchment hydrological response and its spatial organization by integrating geospatial data on topography, land-surface properties and precipitation obtained from geographic information systems, gauging networks and remote sensing. Although preliminary, our results indicate the potential for using fine-resolution hydrologic models over large semiarid regional watersheds such as the Upper Ro Grande.

  16. Preliminary n-alkane results from Basin Substation, BBCP

    NASA Astrophysics Data System (ADS)

    Baczynski, A. A.; McInerney, F. A.; Wing, S. L.

    2012-12-01

    The Bighorn Basin, Wyoming preserves an unusually complete continental stratigraphic record of the early Paleogene. The early Paleogene was a greenhouse climate state, upon which was superimposed a series of transient, extreme global warming events known as hyperthermals. During the summer of 2011, the Bighorn Basin Coring Project (BBCP) drilled two overlapping cores at three sites in the Bighorn Basin (Basin Substation, Polecat Bench, and Gilmore Hill) in an effort to develop high-resolution proxy records across early Paleogene hyperthermal events. The Basin Substation and Polecat Bench sites targeted the largest Paleogene hyperthermal event, the Paleocene-Eocene Thermal Maximum (PETM), and the Gilmore Hill site targeted two smaller hyperthermal events, ETM2 and H2, which occurred after the PETM. Previous analysis of outcrop exposures indicated that PETM sediments at the Basin Substation site generally contained a higher total organic carbon content than sediments at Polecat Bench and Gilmore Hill. Higher weight percent organic carbon often corresponds to better preservation of organic molecules for geochemical analyses. Therefore, for this study, we focused on analyzing the second core drilled at Basin Substation (BBCP-BSN11-1B) for preliminary BBCP organic geochemical analyses. More than 300 samples were collected from the 138.6 m core. n-Alkanes have been extracted and isolated from ~100 of these samples. High molecular weight n-alkanes (C25-C35) with odd-over-even-predominance of chain lengths are used as diagnostic biomarkers of vascular plants in sedimentary rocks because of their high preservation potential and resistance to isotopic exchange. High molecular weight, odd-carbon numbered n-alkanes are being quantified and stable carbon isotope ratios are being measured to develop a high-resolution compound-specific ?13C record across the PETM. This high-resolution n-alkane ?13C record and n-alkane abundance data from unweathered core material have the potential to reveal changes in carbon cycling across the PETM at unprecedented stratigraphic resolution and to provide information about the relative durations of the PETM onset, body, and recovery. PETM conditions in the Bighorn Basin were not ideal for organic matter preservation, perhaps due to high temperature and extreme seasonal precipitation, and even unweathered core material from Basin Substation does not preserve an abundance of n-alkanes. Carbonaceous shale and laminated mudstone appear to have higher abundances of n-alkanes than massive mudstone, siltstone, and sandstone lithologies. n-Alkane abundances and ?13C values from three carbonaceous shales in the Basin Substation core will be compared to samples collected from the same three carbonaceous shales exposed in outcrop to assess the impact of recent weathering on n-alkane preservation in outcrop exposures.

  17. Groundwater vulnerability assessment in Jaworzynka's Valley catchment basin (Tatra Mountains, Poland)

    NASA Astrophysics Data System (ADS)

    Cypel, M.

    2012-04-01

    During the research an attempt was made to assess an intrinsic groundwater vulnerability to contamination in Tatra Mountains (Poland. Assessment of the degree of hazard of permeating pollutions from land surface directly to the ground water table was the main target of the research. The Jaworzynka's Valley in West Tatra Mountains was chosen as the exact research area. Jaworzynka's Valley is a typical karst catchment basin. Location of study area wasn't accidental, because in the north part of the valley there is a well which is being used as drinking water intake for the whole Zakopane City. This is the reason, why the quality of ground water is so important. The method used in this research, entitled KARSTIC, wasn't applied in Poland before. This is a parametric method of groundwater vulnerability assessment. KARSTIC is a modification of much better known DRASTIC method, specialized for specific karst terrain. KARSTIC method created by A. Davis and others (1994), was used for the first time, during a research in the Black Hills Mountains, USA. Research in Jaworzynka's Valley was based on the Black Hills study. In order to apply this method in Tatra Mountains, it was necessary to make a few changes in relation to original area. Applying KARSTIC method consists of successive stages. Schematization of hydrogeological conditions is an inseparable part of KARSTIC method. The first step bases on collecting all of available data such as maps, databases and documentations. Next stage consists of classifying all parameters employed in this method and then assigning a ratings and weights for this parameters. Subsequently it is necessary to use a mathematical formula, named Pollution Potential Index, which presents a ground water vulnerability in each point. The final step is visualization on the ground water vulnerability map. The result of research displays the high vulnerability in close proximity of the drinking water intake. The most vulnerable areas in Jaworzynka's Valley are spring-beds, consequence of very intensive karst development. The rest of research terrain was classified as medium and low vulnerable. KARSTIC method didn't show caves in the valley as high vulnerable, which is certainly incorrect, proving the method to be insufficiently detailed in such cases. During the research, it turned out that using this method in highmountains terrains is not simple. Even a definition of aquifer in highmountains karst areas is difficult (aquifer is not continuous layer and also depth to water is frequently changing). Therefore author decided to continue research about ground water vulnerability assessment in Tatra Mountains, but in a much more detailed form.

  18. Application of strontium isotope measurements to trace sediment sources in an upstream agricultural catchment (Loire River basin, France)

    NASA Astrophysics Data System (ADS)

    Le Gall, Marion; Evrard, Olivier; Thil, Franois; Foucher, Anthony; Salvador-Blanes, Sbastien; Cerdan, Olivier; Ayrault, Sophie

    2015-04-01

    Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. It accelerates the supply of sediment to the rivers and degrades water quality. To limit those impacts and optimize management programs in such areas, sources of sediment need to be identified and sediment transport to be controlled. Here, we determined the sources of suspended sediment in the Louroux (24 km, French Loire River basin), a small catchment representative of lowland cultivated environments of Northwestern Europe. In this catchment, channels have been reshaped and 220 tile drain outlets have been installed over the last several decades. As a result, soil erosion and sediment fluxes have increased drastically. The variation of 87Sr/86Sr ratios, driven by the weathering of rocks with different ages and chemical composition, may reflect the mixing of different sediment sources. Strontium isotopic ratios (87Sr/86Sr) were therefore determined in potential soil sources, suspended particulate matter (SPM) and a sediment core sampled in the Louroux Pond at the catchment outlet. Soil, SPM and core samples displayed significantly different isotopic signatures. 87Sr/86Sr ratios in soil samples varied from 0.712763 to 0.724631 0.000017 (2?, n=20). Highest values were observed in silicic parts of the catchment whereas the lower values were identified in a calcareous area close to the Louroux Pond. 87Sr/86Sr ratios in SPM (0.713660 to 0.725749 0.000017, 2?, n=20) plotted between the soil and sediment core (0.712255 to 0.716415 0.000017, 2?, n=12), suggesting the presence of particles originating from at least two different lithological sources, i.e. silicic rocks and carbonate material. Variations in 87Sr/86Sr ratios in the outlet core sample were used to reconstruct the sedimentary dynamics in the catchment during the last decades. These results will guide the future implementation of appropriate management practices aiming to reduce erosion in upstream catchments and the subsequent transport of sediment degrading the stream systems and the filling of reservoirs. Keywords: soil erosion; 87Sr/86Sr isotopic ratio; end-members; mixing models

  19. Paired Catchment Modeling Study for a Monsoon Flood Event in Neighboring Semi-Arid Basins, New Mexico

    NASA Astrophysics Data System (ADS)

    Wyckoff, R. L.; Vivoni, E. R.

    2005-12-01

    Flooding in ephemeral stream networks can significantly impact channel geomorphology, sediment transport, biogeochemical cycles, and water availability for consumptive and recreational use. In order to better understand the spatial patterns of flooding, distributed models may provide an opportunity for further investigation of rainfall-runoff dynamics in headwater semi-arid catchments including flood generation in ungauged portions of a watershed. For example, the Rio Puerco in west-central New Mexico is an ephemeral tributary of the Rio Grande spanning approximately 18,896 km2 with mountainous forests to the north and semi-arid desert to the south. In mid-September 2003, a series of late monsoonal storms traversed the northern extent of watershed resulting in a flood pulse which propagated through the main reach of the catchment and into the Rio Grande thereby substantially influencing streamflow as far south as Elephant Butte Reservoir (289 km). Radar data suggests flooding most likely emanated from two neighboring sub-catchments within the upper reaches of the watershed. In order to better understand the source of significant hydrologic events within the catchment, we utilize a fully distributed model to simulate the flood within the gauged Upper Rio Puerco Watershed (1119 km2) as well as the immediately adjacent but ungauged Torreon Wash (1344 km2). The TIN-Based Real-time Integrated Basin Simulator (tRIBS) prioritizes interactions between the vadose and saturated zone through the simulation of downward moving infiltration fronts and a variable groundwater surface. Topography is captured through a multiple resolution triangular irregular network (TIN) which accurately represents changes in elevation and simultaneously diminishes the model's computational demands. In addition to faithfully modeling topographic features, tRIBS requires accurate representation and calibration of soil, land use features, and geomorphic data. Calibration is performed through a manual procedure in which parameter values are adjusted in an effort to match an observed stream hydrograph with the model output for a series of storm and inter-storm periods. Following model calibration, we transfer the parameter set to the neighboring Torreon Wash. Model results for the paired catchment study demonstrate the appropriateness of parameter transfer between two neighboring semi-arid catchments.

  20. The importance of earthquake-triggered landslides for catchment sediment yield: a case study of the Siret basin (Romania)

    NASA Astrophysics Data System (ADS)

    Vanmaercke, Matthias; Obreja, Florin; Poesen, Jean

    2014-05-01

    Recent studies have shown that seismic activity may have an important influence on catchment sediment yields (SY, [t/km/y]), e.g. due to earthquake-triggered landslides (EQL). Nonetheless, relatively little is known about the overall importance of EQL for SY. Therefore, this study explored the role of seismic activity in explaining spatial and temporal variation in sediment export for the Siret Basin (Romania), a catchment characterized by a very large variability in seismic activity. Based on long-term (> 30 years) sediment export measurements for 38 subcatchments of the Siret, we found that spatial variation in annual SY, is mainly explained by the degree of seismic activity (R = 0.74) and catchment lithology (R = 0.67) of each catchment. The combination of these two factors accounted for ca. 80% of the observed variation in SY. Other factors (e.g. topography, land use, climate, runoff) did not significantly contribute to the explained variance. To investigate the role of EQL in explaining this seismic control, we studied the temporal changes in sediment concentrations before and after the 7.4 Mw earthquake of 1977 for ten subcatchments of the Siret. Results showed a significant increase in sediment transport in the first years after the earthquake with median sediment concentrations at unit runoff discharge being up to 6 times larger in the year after the earthquake. However, these increases in sediment transport were only observed for rivers that were relatively far away from the epicenter (> 70 km). A possible explanation for this is that rivers close to the epicenter already had a very high sediment input from earlier EQL-events, resulting in no clear increase in sediment transport after the 1977 earthquake. Also available river cross-section data indicate patterns of aggradation close to the epicenter, suggesting that these rivers could not evacuate the increased sediment input.

  1. Daily anomalous high flow (DAHF) of a headwater catchment over the East River basin in South China

    NASA Astrophysics Data System (ADS)

    Chen, Ji; Niu, Jun; Sivakumar, Bellie

    2014-11-01

    This study develops a new method for analyzing the terrestrial hydrologic responses to precipitation through using level-based daily anomalous high flow (DAHF) occurrence in a catchment. The objectives of this study are twofold: (1) to explore the DAHF features over a headwater catchment; and (2) to evaluate the performance of a hydrologic model for DAHF simulation. In this study, DAHF is defined as the daily streamflow on a given day, whose deseasonalised daily streamflow is larger than a given multiplier of the standard deviation (STD) of the long-term deseasonalised streamflow series. Streamflow observations of a headwater catchment over the period of 1952-1972 (i.e., before reservoir operation) at the Longchuan station in the East River basin in South China are studied. The macro-scale Variable Infiltration Capacity (VIC) model is used for streamflow simulation in the catchment, and wavelet analysis is performed to explore the DAHF variability. The study reveals that the percentages of the number of days with the first and second levels of DAHFs are 4.2% and 1%, respectively, for the observed streamflows, while the corresponding percentages for the VIC model-simulated streamflow are 5% and 1.3%, respectively. Application of the Kolmogorov-Smirnov goodness-of-fit test indicates that these two levels of DAHFs can be described by two probability distribution functions, namely the Lognormal distribution and Generalized Extreme Value Type II distribution, respectively. The variability spectrum of the first level DAHF is basically consistent with that of antecedent precipitation, but not for the second level DAHF, as revealed by the wavelet analysis. The VIC model has better performance on the variability simulation of the first level of DAHF.

  2. Tectonic controls of the North Anatolian Fault System (NAFS) on the geomorphic evolution of the alluvial fans and fan catchments in Erzincan pull-apart basin; Turkey

    NASA Astrophysics Data System (ADS)

    Sarp, Gulcan

    2015-02-01

    The Erzincan pull-apart basin is located in the eastern section of the North Anatolian Fault System (NAFS). The tectonic evolution of this basin is mostly controlled by strike slip master faults of the NAFS. This study examines the topography-structure relationships in an effort to evaluate the tectonic signatures in the landscape, paying special attention to recent tectonic activity. In the study, the main focus is on the tectonic controls of the NAFS on the geomorphic evolution of alluvial fans and fan catchments in the Erzincan pull-apart basin. The observations of the amount of tilting of the alluvial fans (?) and its relation with morphometric (Asymmetry Factor (AF), Hypsometric Integral (HI), Fractal analysis of drainage networks (D)) properties of the fan catchments provide valuable information about the tectonic evolution of the basin area. The results of the analyses showed that the alluvial fan and fan catchment morphology in the pull-apart basin are mainly controlled by the ongoing tectonic activity of the NAFS. The fault system in the basin has controlled the accommodation space by causing differential subsidence of the basin, and aggradation processes by causing channel migration, channel incision and tilting the alluvial fans.

  3. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Base-Flow Index, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the mean base-flow index expressed as a percent, compiled for every catchment of MRB_E2RF1 catchments of Major River Basins (MRBs, Crawford and others, 2006). Base flow is the component of streamflow that can be attributed to ground-water discharge into streams. The source data set is Base-Flow Index for the Conterminous United States (Wolock, 2003). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every catchment of MRB_E2RF1 catchments for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  4. Soil and plant composition in the Noun river catchment basin, Western Cameroon: a contribution to the development of a biogeochemical baseline

    NASA Astrophysics Data System (ADS)

    Njofang, Clémentine; Matschullat, Jörg; Amougou, Akoa; Tchouankoué, Jean Pierre; Heilmeier, Hermann

    2009-02-01

    Soils and selected edible plants of the Noun river catchment basin of western Cameroon were sampled to investigate the distribution of trace elements, based on the preliminary idea of unusual anomalies. Analytical techniques for trace elements included ICP-AES, GF-AAS, and ICP-MS. Further soil analyses comprised the mineralogy and contents of the biogenic elements carbon, nitrogen and sulphur (CNS). The trace element concentrations in the soils reflect those of the lithogeochemical background of the pluto-volcanic rocks of the region. This is consistent with the results from the mineralogical analyses and physicochemical parameters such as pH, taken in the field, which also do not suggest any geochemical anomaly. Most trace elements analyzed in the plants showed concentrations that reflect those of the soils (Al, Fe, Ti, and Rb). However, some trace elements were enriched in the plants as compared to the soils, such as Zn, Cu, Cd, Mo (excluding yam), Ni (peanut), Ba (peanut), Sr (peanut, bean), and B. Trace elements such as As, Cr, V, and Se were not bioavailable for all the analyzed plants. Besides, trace elements such as Cu, Zn, Mo, Fe, Al, Ni, B, Ti, Rb, Cs, and Ba were in the range of phytotoxicity and reached or exceeded human food tolerance level (Cu). The plants with seeds showed a higher absorption of trace elements compared to plants with tubercles.

  5. The Immatsiak network of groundwater wells in a small catchment basin in the discontinuous permafrost zone of Northern Quebec, Canada: A unique opportunity for monitoring the impacts of climate change on groundwater (Invited)

    NASA Astrophysics Data System (ADS)

    Fortier, R.; Lemieux, J.; Molson, J. W.; Therrien, R.; Ouellet, M.; Bart, J.

    2013-12-01

    During a summer drilling campaign in 2012, a network of nine groundwater monitoring wells was installed in a small catchment basin in a zone of discontinuous permafrost near the Inuit community of Umiujaq in Northern Quebec, Canada. This network, named Immatsiak, is part of a provincial network of groundwater monitoring wells to monitor the impacts of climate change on groundwater resources. It provides a unique opportunity to study cold region groundwater dynamics in permafrost environments and to assess the impacts of permafrost degradation on groundwater quality and availability as a potential source of drinking water. Using the borehole logs from the drilling campaign and other information from previous investigations, an interpretative cryo-hydrogeological cross-section of the catchment basin was produced which identified the Quaternary deposit thickness and extent, the depth to bedrock, the location of permafrost, one superficial aquifer located in a sand deposit, and another deep aquifer in fluvio-glacial sediments and till. In the summer of 2013, data were recovered from water level and barometric loggers which were installed in the wells in August 2012. Although the wells were drilled in unfrozen zones, the groundwater temperature is very low, near 0.4 C, with an annual variability of a few tenths of a degree Celsius at a depth of 35 m. The hydraulic head in the wells varied as much as 6 m over the last year. Pumping tests performed in the wells showed a very high hydraulic conductivity of the deep aquifer. Groundwater in the wells and surface water in small thermokarst lakes and at the catchment outlet were sampled for geochemical analysis (inorganic parameters, stable isotopes of oxygen (?18O) and hydrogen (?2H), and radioactive isotopes of carbon (?14C), hydrogen (tritium ?3H) and helium (?3He)) to assess groundwater quality and origin. Preliminary results show that the signature of melt water from permafrost thawing is observed in the geochemistry of groundwater and surface water at the catchment outlet. Following synthesis of the available information, including a cryo-hydrogeophysical investigation in progress, a three-dimensional hydrogeological conceptual and numerical model of the catchment basin will be developed. According to different scenarios of climate change, the potential of using groundwater as a sustainable resource in northern regions will be assessed by simulating the present and future impacts of climate change on this groundwater system.

  6. Monitoring of fluvial transport in small upland catchments - methods and preliminary results

    NASA Astrophysics Data System (ADS)

    Janicki, Grzegorz; Rodzik, Jan; Chabudzi?ski, ?ukasz; Franczak, ?ukasz; Si?uch, Marcin; St?pniewski, Krzysztof; Dyer, Jamie L.; Ko?odziej, Grzegorz; Maciejewska, Ewa

    2014-06-01

    In April 2011 a study was initiated, financed from resources of the Polish National Science Centre, entitled: Rainstorm prediction and mathematic modelling of their environmental and social-economical effects (No. NN/306571640). The study, implemented by a Polish-American team, covers meteorological research, including: (1) monitoring of single cell storms developing in various synoptic situations, (2) detection of their movement courses, and (3) estimation of parameters of their rain field. Empirical studies, including hydrological and geomorphological measurements, are conducted in objects researched thoroughly in physiographic terms (experimental catchments) in the Lublin region (SE Poland), distinguished by high frequency of occurrence of the events described. For comparative purposes, studies are also carried out on selected model areas in the lower course of the Mississippi River valley (USA), in a region with high frequency of summer rainstorms. For detailed studies on sediment transport processes during rainstorm events, catchments of low hydrological rank and their sub-catchments in a cascade system were selected. For the basic, relatively uniform geomorpho logical units distinguished this way, erosion and deposition balance of material transported was determined. The aim of work was to determine influence of weather condition on fluvial transport rate in small catchment with low hydrological order

  7. Groundwater storage change in the Ngadda Catchment of the Lake Chad Basin using GRACE and ground truth data

    NASA Astrophysics Data System (ADS)

    Skaskevych, A.; Lee, J.

    2013-12-01

    The present study is to analyze groundwater storage variations in the Ngadda Catchment located in the southwestern edge of Lake Chad Basin using Gravity Recovery and Climate Experiment (GRACE) data. We collected monthly total water storage data from GRACE and monthly soil moisture data from Global Land Data Assimilation System (GLDAS) for the period of 2005 - 2009 with the spatial resolution of 1 and 0.25 degrees. We assumed surface water contributions to be negligible in the study area. The estimated groundwater storage changes were compared to the ground truth groundwater depth data collected in 2005 and 2009. The challenge of the present study is sparseness of the ground truth data in space and time. The study area is one of the data poor regions in the world due to the limited accessibility to the area. Different geostatistical techniques such as Kriging, Thiessen polygons, and Bayesian updating were applied to overcome such sparseness and modeling uncertainty under different scales and resolution. The study shows a significant increase of groundwater storage in the Ngadda catchment during the study period. Uncertainty is significant though depending on the size of the model and modeling technique. The study discusses advantages of using remote sensing data in data poor regions and how geostatistical techniques can be applied to deal with modeling uncertainty.

  8. Environmental isotopic and hydrochemical characteristics of groundwater from the Sandspruit Catchment, Berg River Basin, South Africa.

    PubMed

    Naicker, S; Demlie, M

    2014-01-01

    The Sandspruit catchment (a tributary of the Berg River) represents a drainage system, whereby saline groundwater with total dissolved solids (TDS) up to 10,870 mg/l, and electrical conductivity (EC) up to 2,140 mS/m has been documented. The catchment belongs to the winter rainfall region with precipitation seldom exceeding 400 mm/yr, as such, groundwater recharge occurs predominantly from May to August. Recharge estimation using the catchment water-balance method, chloride mass balance method, and qualified guesses produced recharge rates between 8 and 70 mm/yr. To understand the origin, occurrence and dynamics of the saline groundwater, a coupled analysis of major ion hydrochemistry and environmental isotopes (?(18)O, ?(2)H and (3)H) data supported by conventional hydrogeological information has been undertaken. These spatial and multi-temporal hydrochemical and environmental isotope data provided insight into the origin, mechanisms and spatial evolution of the groundwater salinity. These data also illustrate that the saline groundwater within the catchment can be attributed to the combined effects of evaporation, salt dissolution, and groundwater mixing. The salinity of the groundwater tends to vary seasonally and evolves in the direction of groundwater flow. The stable isotope signatures further indicate two possible mechanisms of recharge; namely, (1) a slow diffuse type modern recharge through a relatively low permeability material as explained by heavy isotope signal and (2) a relatively quick recharge prior to evaporation from a distant high altitude source as explained by the relatively depleted isotopic signal and sub-modern to old tritium values. PMID:24552734

  9. Analysis of catchment behavior using residence time distributions with application to the Thuringian Basin

    NASA Astrophysics Data System (ADS)

    Prykhodko, Vladyslav; Hee, Falk; Kumar, Rohini; Samaniego, Luis; Attinger, Sabine

    2014-05-01

    Residence time distribution (RTD), as presented e.g. by Botter et al., are a novel mathematical framework for a quantitative characterization of hydrological systems. These distributions contain information about water storage, flow pathways and water sources and therefore improve the classical hydrograph methods by allowing both nonlinear as well as time-dependent dynamics. In our study we extend this previous works by applying this theoretical framework on real-world heterogeneous catchments. To that end we use a catchment-scale hydrological model (mHM) and apply the approach of Botter et al. to each spatial grid cell of mHM. To facilitate the coupling we amended Botter's approach by introducing additional fluxes (like runoff from unsaturated zone) and specifying the structure of the groundwater zone. By virtue of this coupling we could then make use of the realistic hydrological fluxes and state variables as provided by mHM. This allowed us to use both observed (precipitation, temperature, soil type etc.) and modeled data sets and asses their impact on the behavior of the resulting RTD's. We extended the aforementioned framework to analyze large catchments by including geomorphic effect due to the actual arrangement of subcatchments around the channel network using the flood routing algorithm of mHM. Additionally we study dependencies of the stochastic characteristics of RTD's on the meteorological and hydrological processes as well as on the morphological structure of the catchment. As a result we gained mean residence times (MRT) of base flow and groundwater flow on the mesoscale (4km x 4km). We compare the spatial distribution of MRT's with land cover and soil moisture maps as well as driving forces like precipitation and temperature. Results showed that land cover is a major predictor for MRT's whereas its impact on the mean evapotranspiration time was much lower. Additionally we determined the temporal evolution of mean travel times by using time series of all relevant hydrological processes (observed as well as modeled by mHM) from 1960-2010. Our analysis revealed the strong regularity of the catchment dynamics over long time periods. The strong seasonal changes of MRT's, usually modeled by sine-wave approach, could be approximated by sawtooth-wave model. Our future work will be focused on comparing of our numerical results with realistic data from tracer experiments and isotope measurements.

  10. Attributes for MRB_E2RF1 Catchments by Major Rivers Basins in the Conterminous United States: Total Precipitation, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the catchment-average total precipitation in millimeters multiplied by 100 for 2002, compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data were the Near-Real-Time Monthly High-Resolution Precipitation Climate Data Set for the Conterminous United States (2002) raster data set produced by the Spatial Climate Analysis Service at Oregon State University. The MRB_E2RF1 catchments are based on a modified version of the Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  11. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Average Atmospheric (Wet) Deposition of Inorganic Nitrogen, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the average atmospheric (wet) deposition, in kilograms per square kilometer, of inorganic nitrogen for the year 2002 compiled for every catchment for MRB_E2RF1 of Major River Basins (MRBs, Crawford and others, 2006). The source data set for wet deposition was from the USGS's raster data set atmospheric (wet) deposition of inorganic nitrogen for 2002 (Gronberg, 2005). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every catchment of MRB_E2RF1 catchments for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  12. Isotope methods as a tool to characterize nitrate origin and transport in Kocinka catchment (central Poland): preliminary results

    NASA Astrophysics Data System (ADS)

    Zurek, Anna; Wachniew, Przemyslaw; Witczak, Stanislaw; Rozanski, Kazimierz; Kania, Jaroslaw

    2014-05-01

    Kocinka catchment with 258 km2 of surface area is one of the Soils2Sea project (BONUS programme) case studies. One of the main scientific objectives of this project is to analyze how changes in land use and climate may affect the nutrient load to the Baltic Sea. Hydrogeological conditions in the Kocinka catchment are determined by Quaternary glacial till and glacifluvial sands and gravels underlain by karstic-fractured limestones which compose the Upper Jurassic Major Groundwater Basin (MGWB 326), one of four most important groundwater reservoirs in Poland. Pollution with nitrates is the most important threat to groundwater quality in this groundwater body. The concentration of nitrate in some wells, in the southern part of Kocinka catchment where outcrops of Jurassic limestones occur, exceeds the maximum permissible level of 50 mgNO3/L and constantly increases. A prerequisite for measures to reduce NO3 loads to the groundwater body is identification of sources of nitrate pollution. The working hypothesis links the high nitrate concentrations with the leaking sewage system in Czestochowa city and its surroundings but agricultural sources cannot be excluded as 66% of Kocinka catchment area is used agriculturally. A dedicated study employing environmental tracers was launched with the main aim of quantifying the pathways and dynamic of groundwater flow in the aquifer. Tritium was found throughout the system but its concentrations vary considerably. Decrease of tritium contents with depth in the aquifer was observed in one of wells. This points to active recharge and characteristic time scales of groundwater flow in order of years to several decades. To identify the origin of nitrate pollution nitrogen and oxygen isotope ratios of dissolved nitrate was analyzed in a number of wells with high nitrate concentrations. The isotopic composition of dissolved nitrates does not confirm the hypothesis on the decisive role of urban sewage in nitrate pollution. The isotope date point to agriculture as the main source of NO3. The isotopic data provided no evidences for natural denitrification in the aquifer. However, only water samples with considerable amounts of nitrates were analyzed for 15N and 18O. On the other hand, low NO3 concentrations in the deeper part of aquifer can be due to denitrification or long residence time of this water. Acknowledgements. The work was carried out as part of the project Soils2Sea in BONUS programme and the statutory funds of the AGH University of Science and Technology (project No.11.11.140.026 and 11.11.220.01).

  13. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Basin Characteristics, 2002 Geospatial_Data_Presentation_Form: tabular digital data

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents basin characteristics for the year 2002 compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). These characteristics are reach catchment shape index, stream density, sinuosity, mean elevation, mean slope and number of road-stream crossings. The source data sets are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011) and the U.S. Census Bureau's TIGER/Line Files (U.S. Census Bureau,2006). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  14. Preliminary investigations of toxicity in the Georges Bay catchment, Tasmania, Australia

    PubMed Central

    Bleaney, Alison; Hickey, Christopher W.; Stewart, Michael; Scammell, Marcus; Senjen, Rye

    2015-01-01

    North-eastern Tasmania, Australia has been an area of major production for Pacific oysters (Crassostrea gigas) for over 25 years. Since the mid-1990s, increased oyster mortality has been observed. The purpose of the present study was to identify the agent causing aquatic toxicity and to investigate whether there is a chemical and/or toxicological link between river foam and monoculture timber plantation forests of exotic eucalypts (Eucalyptus nitens) present in the catchment area. Foam samples from the George River catchment demonstrated high toxicity to a freshwater cladoceran and larvae of a marine blue mussel species. After filtration to remove most particulates, foam samples also demonstrated a marked reduction in toxicity to blue mussels, which suggested that the toxicity is particle associated. Foam and leaf extracts of E. nitens were then fractionated using HPLC and size exclusion chromatography and the resulting fractions were screened for cladoceran and blue mussel toxicity. Toxicity was detected in fractions common to both the foam and the leaf extracts. This study suggests that there may be a chemical and toxicological relationship between foam and E. nitens leaf components. PMID:25745193

  15. Projected impacts of climate change on groundwater and stormflow in a humid, tropical catchment in the Ugandan Upper Nile Basin

    NASA Astrophysics Data System (ADS)

    Kingston, D. G.; Taylor, R. G.

    2010-03-01

    The changing availability of freshwater resources is likely to be one of the most important consequences of projected 21st century climate change for both human and natural systems. However, substantial uncertainty remains regarding the precise impacts of climate change on water resources, due in part to uncertainty in GCM projections of climate change. Here we explore the potential impacts of climate change on water resources in a humid, tropical catchment (the River Mitano) in the Upper Nile Basin of Uganda. Uncertainty associated with GCM structure and climate sensitivity is explored, as well as from parameter specification within hydrological models. This is achieved by running pattern-scaled GCM output through a semi-distributed hydrological model (developed using SWAT) of the catchment. Importantly, use of pattern-scaled GCM output allows investigation of specific thresholds of global climate change including the purported 2 C threshold of "dangerous" climate change. In-depth analysis of results based on HadCM3 climate scenarios shows that annual river discharge first increases, then declines with rising global mean air temperature. A coincidental shift from a bimodal to unimodal discharge regime also results from a projected reduction in baseflow (groundwater discharge). Both of these changes occur after a 4 C rise in global mean air temperature. These results are, however, highly GCM dependent in both the magnitude and direction of change. This dependence stems primarily from projected differences in GCM scenario precipitation rather than temperature. GCM-related uncertainty is far greater than that associated with climate sensitivity or hydrological model parameterisation.

  16. Preliminary catalog of the sedimentary basins of the United States

    USGS Publications Warehouse

    Coleman, James L., Jr.; Cahan, Steven M.

    2012-01-01

    One hundred forty-four sedimentary basins (or groups of basins) in the United States (both onshore and offshore) are identified, located, and briefly described as part of a Geographic Information System (GIS) data base in support of the Geologic Carbon Dioxide Sequestration National Assessment Project (Brennan and others, 2010). This catalog of basins is designed to provide a check list and basic geologic framework for compiling more detailed geologic and reservoir engineering data for this project and other future investigations.

  17. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Average Daily Maximum Temperature, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    The MRB_E2RF1 catchments are based on a modified version of the Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2008). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  18. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Average Daily Minimum Temperature, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    The MRB_E2RF1 catchments are based on a modified version of the Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  19. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: STATSGO Soil Characteristics

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents estimated soil variables compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The variables included are cation exchange capacity, percent calcium carbonate, slope, water-table depth, soil thickness, hydrologic soil group, soil erodibility (k-factor), permeability, average water capacity, bulk density, percent organic material, percent clay, percent sand, and percent silt. The source data set is the State Soil ( STATSGO ) Geographic Database (Wolock, 1997). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  20. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Level 3 Ecoregions

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the estimated area of level 3 ecological landscape regions (ecoregions), as defined by Omernik (1987), compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). The source data set is Level III Ecoregions of the Continental United States (U.S. Environmental Protection Agency, 2003). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  1. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Level 3 Nutrient Ecoregions, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the area of each level 3 nutrient ecoregion in square meters compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). The source data are from the 2002 version of the U.S. Environmental Protection Agency's (USEPA) Aggregations of Level III Ecoregions for National Nutrient Assessment & Management Strategy (USEPA, 2002). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  2. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Normalized Atmospheric Deposition for 2002, Ammonium (NH4)

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the average normalized (wet) deposition, in kilograms per square kilometer multiplied by 100, of ammonium (NH4) for the year 2002 compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). Estimates of NH4 deposition are based on National Atmospheric Deposition Program (NADP) measurements (B. Larsen, U.S. Geological Survey, written. commun., 2007). De-trending methods applied to the year 2002 are described in Alexander and others, 2001. NADP site selection met the following criteria: stations must have records from 1995 to 2002 and have a minimum of 30 observations. The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  3. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Average Saturation Excess-Overland Flow, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the average value of saturation overland flow, in percent of total streamflow, compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data set is Saturation Overland Flow Estimated by TOPMODEL for the Conterminous United States (Wolock, 2003). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  4. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Hydrologic Landscape Regions

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the area of Hydrologic Landscape Regions (HLR) compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). The source data set is a 100-meter version of Hydrologic Landscape Regions of the United States (Wolock, 2003). HLR groups watersheds on the basis of similarities in land-surface form, geologic texture, and climate characteristics. The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  5. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: 30-Year Average Daily Minimum Temperature, 1971-2000

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents thecatchment-average for the 30-year (1971-2000) average daily minimum temperature in Celsius multiplied by 100 compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data were the United States Average Monthly or Annual Minimum Temperature, 1971 - 2000 raster data set produced by the PRISM Group at Oregon State University. The MRB_E2RF1 catchments are based on a modified version of the Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  6. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Normalized Atmospheric Deposition for 2002, Total Inorganic Nitrogen

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the average normalized atmospheric (wet) deposition, in kilograms per square kilometer multiplied by 100, of Total Inorganic Nitrogen for the year 2002 compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). Estimates of Total Inorganic Nitrogen deposition are based on National Atmospheric Deposition Program (NADP) measurements (B. Larsen, U.S. Geological Survey, written. commun., 2007). De-trending methods applied to the year 2002 are described in Alexander and others, 2001. NADP site selection met the following criteria: stations must have records from 1995 to 2002 and have a minimum of 30 observations. The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  7. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: 30-Year Average Annual Precipitation, 1971-2000

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the 30-year (1971-2000) average annual precipitation in millimeters multiplied by 100 compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data were the United States Average Monthly or Annual Minimum Precipitation, 1971 - 2000 raster data set produced by the PRISM Group at Oregon State University. The MRB_E2RF1 catchments are based on a modified version of the Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; J.W. Brakebill, U.S. Geological Survey, written commun., 2008). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  8. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Estimated Mean Annual Natural Groundwater Recharge, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the mean annual natural groundwater recharge, in millimeters, compiled for every MRB_E2RF1catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data set is Estimated Mean Annual Natural Ground-Water Recharge in the Conterminous United States (Wolock, 2003). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  9. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Mean Infiltration-Excess Overland Flow, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the mean value for infiltration-excess overland flow as estimated by the watershed model TOPMODEL, compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). The source data set is Infiltration-Excess Overland Flow Estimated by TOPMODEL for the Conterminous United States (Wolock, 2003). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  10. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Mean Annual R-factor, 1971-2000

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the average annual R-factor, rainfall-runoff erosivity measure, compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data are from Christopher Daly of the Spatial Climate Analysis Service, Oregon State University, and George Taylor of the Oregon Climate Service, Oregon State University (2002). The ERF1_2 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  11. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Normalized Atmospheric Deposition for 2002, Nitrate (NO3)

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the average normalized (wet) deposition, in kilograms per square kilometer multiplied by 100, of Nitrate (NO3) for the year 2002 compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). Estimates of NO3 deposition are based on National Atmospheric Deposition Program (NADP) measurements (B. Larsen, U.S. Geological Survey, written. commun., 2007). De-trending methods applied to the year 2002 are described in Alexander and others, 2001. NADP site selection met the following criteria: stations must have records from 1995 to 2002 and have a minimum of 30 observations. The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  12. Post-wildfire recovery of water yield in the Sydney Basin water supply catchments: An assessment of the 2001/2002 wildfires

    NASA Astrophysics Data System (ADS)

    Heath, J. T.; Chafer, C. J.; van Ogtrop, F. F.; Bishop, T. F. A.

    2014-11-01

    Wildfire is a recurring event which has been acknowledged by the literature to impact the hydrological cycle of a catchment. Hence, wildfire may have a significant impact on water yield levels within a catchment. In Australia, studies of the effect of fire on water yield have been limited to obligate seeder vegetation communities. These communities regenerate from seed banks in the ground or within woody fruits and are generally activated by fire. In contrast, the Sydney Basin is dominated by obligate resprouter communities. These communities regenerate from fire resistant buds found on the plant and are generally found in regions where wildfire is a regular occurrence. The 2001/2002 wildfires in the Sydney Basin provided an opportunity to investigate the impacts of wildfire on water yield in a number of catchments dominated by obligate resprouting communities. The overall aim of this study was to investigate whether there was a difference in water yield post-wildfire. Four burnt subcatchments and 3 control subcatchments were assessed. A general additive model was calibrated using pre-wildfire data and then used to predict post-wildfire water yield using post-wildfire data. The model errors were analysed and it was found that the errors for all subcatchments showed similar trends for the post-wildfire period. This finding demonstrates that wildfires within the Sydney Basin have no significant medium-term impact on water yield.

  13. Attributes for MRB_E2RF1 Catchments in Selected Major River Basins of the Conterminous United States: Contact Time, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the average contact time, in units of days, compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). Contact time, as described in Vitvar and others (2002), is defined as the baseflow residence time in the subsurface. The source data set was the U.S. Geological Survey's (USGS) 1-kilometer grid for the conterminous United States (D.M. Wolock, U.S. Geological Survey, written commun., 2008). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  14. Estimation of the Relative Severity of Floods in Small Ungauged Catchments for Preliminary Observations on Flash Flood Preparedness: A Case Study in Korea

    PubMed Central

    Kim, Eung Seok; Choi, Hyun Il

    2012-01-01

    An increase in the occurrence of sudden local flooding of great volume and short duration has caused significant danger and loss of life and property in Korea as well as many other parts of the World. Since such floods usually accompanied by rapid runoff and debris flow rise quite quickly with little or no advance warning to prevent flood damage, this study presents a new flash flood indexing methodology to promptly provide preliminary observations regarding emergency preparedness and response to flash flood disasters in small ungauged catchments. Flood runoff hydrographs are generated from a rainfall-runoff model for the annual maximum rainfall series of long-term observed data in the two selected small ungauged catchments. The relative flood severity factors quantifying characteristics of flood runoff hydrographs are standardized by the highest recorded maximum value, and then averaged to obtain the flash flood index only for flash flood events in each study catchment. It is expected that the regression equations between the proposed flash flood index and rainfall characteristics can provide the basis database of the preliminary information for forecasting the local flood severity in order to facilitate flash flood preparedness in small ungauged catchments. PMID:22690208

  15. Preliminary stratigraphic and paleomagnetic results from Neogene basins across the Anatolian Plateau (Turkey).

    NASA Astrophysics Data System (ADS)

    Lucifora, Stella; Cifelli, Francesca; Mazzini, Ilaria; Cosentino, Domenico; Mattei, Massimo; Cipollari, Paola; Gliozzi, Elsa; Palolo Cavinato, Gian

    2010-05-01

    An integrated paleomagnetic and stratigraphic study on Neogene basins across the Anatolian Plateau was carried out. This study is developed within the VAMP (Vertical Anatolian Movement Project), an interdisciplinary project aimed to the recent tectonic evolution of the central Anatolian Plateau. The studied areas are located in southern Turkey (Adana, Mut and Ermenek basins) and in northern Turkey (Kazan, Çankiri, Kastamonu, Boyabat and Sinop basins). For paleomagnetic analyses we sampled 1062 standard cylindrical samples from 13 stratigraphic sections, and 746 samples for paleontological analysis were taken from the same sections. AMS (Anisotropy of Magnetic Susceptibility), magnetic mineralogy and paleomagnetic polarity data are presented together with the results of the integrated stratigraphic analyses. In the Southern Turkey basins preliminary results show the diffuse presence of authigenic iron sulphides, together with magnetite, as main magnetic carriers. In these sections the iron-sulphides Characteristic Natural Magnetization (ChRM) component is characterized by inconsistent polarity record, suggesting that iron-sulphides have a late diagenetic origin. Conversely, magnetite bearing sediments show more reliable results in term of magnetic polarity interpretations. Preliminary stratigraphic and paleomagnetic results from the southern margin of the plateau allow us both to refine the stratigraphy for the late Miocene of the Adana Basin and to better constrain the age of the youngest marine deposits of the Mut and Ermenek basins. In the late Miocene of the Adana Basin evidence of the Messinian salinity crisis led to a new stratigraphic framework specially for the Messinian-Pliocene interval. Thick fluvial conglomerates from the uppermost Messinian deposits of the Adana Basin, which could be linked to the activation of the southern margin of the plateau, allow us to constrain at about 5.4 Ma the uplift of the central Anatolian Plateau. On the other hand, the preliminary results of the micropaleontological analyses carried out on the higher marine deposits sampled in the northern part of the Ermenek Basin (Basyayla section, 1840 m a.s.l.) point to a post-Tortonian age for the plateau uplift. The age of the basins at the northern margin of the plateau are very poor constrained, except for that basins containing vertebrate-bearing continental deposits. However, from a palaeogeographic point of view, our preliminary data suggest a possible Tortonian connection between the Çankiri Basin and the Paratethyan realm. This presentation was supported by the EUROCORE programme TOPO-EUROPE of the European Science Foundation.

  16. Characterisation of stable isotopes to identify residence times and runoff components in two meso-scale catchments in the Abay/Upper Blue Nile basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Tekleab, S.; Wenninger, J.; Uhlenbrook, S.

    2014-06-01

    Measurements of the stable isotopes oxygen-18 (18O) and deuterium (2H) were carried out in two meso-scale catchments, Chemoga (358 km2) and Jedeb (296 km2) south of Lake Tana, Abay/Upper Blue Nile basin, Ethiopia. The region is of paramount importance for the water resources in the Nile basin, as more than 70% of total Nile water flow originates from the Ethiopian highlands. Stable isotope compositions in precipitation, spring water and streamflow were analysed (i) to characterise the spatial and temporal variations of water fluxes; (ii) to estimate the mean residence time of water using a sine wave regression approach; and (iii) to identify runoff components using classical two-component hydrograph separations on a seasonal timescale. The results show that the isotopic composition of precipitation exhibits marked seasonal variations, which suggests different sources of moisture generation for the rainfall in the study area. The Atlantic-Indian Ocean, Congo basin, Upper White Nile and the Sudd swamps are the potential moisture source areas during the main rainy (summer) season, while the Indian-Arabian and Mediterranean Sea moisture source areas during little rain (spring) and dry (winter) seasons. The spatial variation in the isotopic composition is influenced by the amount effect as depicted by moderate coefficients of determination on a monthly timescale (R2 varies from 0.38 to 0.68) and weak regression coefficients (R2 varies from 0.18 to 0.58) for the altitude and temperature effects. A mean altitude effect accounting for -0.12/100 m for 18O and -0.58/100 m for 2H was discernible in precipitation isotope composition. Results from the hydrograph separation on a seasonal timescale indicate the dominance of event water, with an average of 71 and 64% of the total runoff during the wet season in the Chemoga and Jedeb catchments, respectively. Moreover, the stable isotope compositions of streamflow samples were damped compared to the input function of precipitation for both catchments. This damping was used to estimate mean residence times of stream water of 4.1 and 6.0 months at the Chemoga and Jedeb catchment outlets, respectively. Short mean residence times and high fractions of event water components recommend catchment management measures aiming at reduction of overland flow/soil erosion and increasing of soil water retention and recharge to enable sustainable development in these agriculturally dominated catchments.

  17. Modelling the water balance of a mesoscale catchment basin using remotely sensed land cover data

    NASA Astrophysics Data System (ADS)

    Montzka, Carsten; Canty, Morton; Kunkel, Ralf; Menz, Gunter; Vereecken, Harry; Wendland, Frank

    2008-05-01

    SummaryHydrological modelling of mesoscale catchments is often adversely affected by a lack of adequate information about specific site conditions. In particular, digital land cover data are available from data sets which were acquired on a European or a national scale. These data sets do not only exhibit a restricted spatial resolution but also a differentiation of crops and impervious areas which is not appropriate to the needs of mesoscale hydrological models. In this paper, the impact of remote sensing data on the reliability of a water balance model is investigated and compared to model results determined on the basis of CORINE (Coordination of Information on the Environment) Land Cover as a reference. The aim is to quantify the improved model performance achieved by an enhanced land cover representation and corresponding model modifications. Making use of medium resolution satellite imagery from SPOT, LANDSAT ETM+ and ASTER, detailed information on land cover, especially agricultural crops and impervious surfaces, was extracted over a 5-year period (2000-2004). Crop-specific evapotranspiration coefficients were derived by using remote sensing data to replace grass reference evapotranspiration necessitated by the use of CORINE land cover for rural areas. For regions classified as settlement or industrial areas, degrees of imperviousness were derived. The data were incorporated into the hydrological model GROWA (large-scale water balance model), which uses an empirical approach combining distributed meteorological data with distributed site parameters to calculate the annual runoff components. Using satellite imagery in combination with runoff data from gauging stations for the years 2000-2004, the actual evapotranspiration calculation in GROWA was methodologically extended by including empirical crop coefficients for actual evapotranspiration calculations. While GROWA originally treated agricultural areas as homogeneous, now a consideration and differentiation of the main crops is possible. The accuracy was determined by runoff measurements from gauging stations. Differences in water balances resulting from the use of remote sensing data as opposed to CORINE were analysed in this study using a representative subcatchment. Resulting Nash-Sutcliff model efficiencies improved from 0.372 to 0.775 and indicate that the enhanced model can produce thematically more accurate and spatially more detailed local water balances. However, the proposed model enhancements by satellite imagery have not exhausted the full potential of water balance modelling, for which a higher temporal resolution is required.

  18. Quantitative catchment profiling to apportion faecal indicator organism budgets for the Ribble system, the UK's sentinel drainage basin for Water Framework Directive research.

    PubMed

    Stapleton, C M; Wyer, M D; Crowther, J; McDonald, A T; Kay, D; Greaves, J; Wither, A; Watkins, J; Francis, C; Humphrey, N; Bradford, M

    2008-06-01

    Under the EU Water Framework Directive (WFD) 20/60/EC and the US Federal Water Pollution Control Act 2002 management of water quality within river drainage basins has shifted from traditional point-source control to a holistic approach whereby the overall contribution of point and diffuse sources of pollutants has to be considered. Consequently, there is a requirement to undertake source-apportionment studies of pollutant fluxes within catchments. The inclusion of the Bathing Water Directive (BWD), under the list of 'protected areas' in the WFD places a requirement to control sources of faecal indicator organisms within catchments in order to achieve the objectives of both the BWD (and its revision - 2006/7/EC) and the WFD. This study was therefore initiated to quantify catchment-derived fluxes of faecal indicator compliance parameters originating from both point and diffuse sources. The Ribble drainage basin is the single UK sentinel WFD research catchment and discharges to the south of the Fylde coast, which includes a number of high profile, historically non-compliant, bathing waters. Faecal indicator concentrations (faecal coliform concentrations are reported herein) were measured at 41 riverine locations, the 15 largest wastewater treatment works (WwTWs) and 15 combined sewer overflows (CSOs) across the Ribble basin over a 44-day period during the 2002 bathing season. The sampling programme included targeting rainfall-induced high flow events and sample results were categorised as either base flow or high flow. At the riverine sites, geometric mean faecal coliform concentrations showed statistically significant elevation at high flow compared to base flow. The resultant faecal coliform flux estimates revealed that over 90% of the total organism load to the Ribble Estuary was discharged by sewage related sources during high flow events. These sewage sources were largely related to the urban areas to the south and east of the Ribble basin, with over half the load associated with the relatively small subcatchment of the River Douglas. The majority of this load was attributed to two WwTWs that discharge through a common outfall close to the tidal limit of this catchment. Budgets adjusted to accommodate the impact of proposed UV disinfection of these effluents showed that the load from these sources would be reduced significantly during base flow conditions. However, during high flow events loads would still remain high due to the operation of storm sewage overflows from stormwater retention tanks. The study identified untreated storm sewage spills from urban infrastructure and WwTW stormwater retention tanks as the dominant component of the high flow flux of faecal indicators to receiving waters of the Fylde coast and the associated bathing waters. PMID:18082929

  19. Assessment of the effects of rainfall variability on the hydrological regime of a small rural catchment in Northwest Spain: preliminary results

    NASA Astrophysics Data System (ADS)

    Rodriguez-Blanco, M. L.; Taboada-Castro, M. M.; Palleiro, L.; Taboada-Castro, M. T.

    2010-05-01

    Knowledge of streamflow regime is required to evaluate water supply and to assess the vulnerability of aquatic habitat. This paper presents preliminary results from analysis of hydrological variability of a 16 km2 catchment near A Corua city, northwest Spain, with particular focus on the effects of rainfall variability, by using the daily streamflow data for the period of October 2004 to September 2009. The analysis is based on the examination of statistical parameters, flow duration characteristics, baseflow separation and investigation of the relationship between measured streamflow and rainfall. The results show that daily, monthly and annual streamflow is highly variable in this catchment. The hydrology of the Corbeira catchment is governed by the natural climatic characteristics of a temperate humid area. At seasonal scale about 65% of the water flows in winter (33%) and spring (32%) months, although with significant differences between years. This seasonality essentially relates to distribution and characteristics of rainfall episodes. However, a good relationship between flow values and monthly rainfall was not observed, probably due to the influence of soil moisture state in the hydrologic response of this catchment. The baseflow contribution to the total streamflow is quite high with values of the baseflow index higher than 0.69, which is consistent with the characteristics of the study area, such as geology (dominated by schist), soils (Umbrisoles and Cambisols), vegetation cover (more than 65% corresponds to forest areas) and rainfall characteristics (heavy, long duration and low intensity). This indicates that the baseflow contributions are mainly responsible for keeping the stream. The flow duration analysis also reveals that the flow regime is dominated by baseflow, recording high flow peaks during a limited period of the year. Flow duration curves have sharp decline from 0.01 to 0.30, indicating that the Corbeira catchment experience rapid flow decrease after the wet season. The study concludes that the major cause of streamflow variability in this catchment is related to rainfall distribution.

  20. Preliminary design report for the K basins integrated water treatment system

    SciTech Connect

    Pauly, T.R., Westinghouse Hanford

    1996-08-12

    This Preliminary Design Report (PDR) provides a revised concept for the K Basins Integrated Water Treatment Systems (IWTS). This PDR incorporates the 11 recommendations made in a May 1996 Value Engineering session into the Conceptual Design, and provides new flow diagrams, hazard category assessment, cost estimate, and schedule for the IWTS Subproject.

  1. Integrating dynamic ecohydrological relations with the catchment response: A multi-scale hydrological modeling effort in a monsoonal regime basin

    NASA Astrophysics Data System (ADS)

    Mendez-Barroso, L. A.; Vivoni, E.; Robles-Morua, A.; Yepez, E. A.; Rodriguez, J. C.; Watts, C.; Saiz-Hernandez, J.

    2013-05-01

    Seasonal vegetation changes highly affect the energy and hydrologic fluxes in semiarid regions around the world. Accounting for different water use strategies among drought-deciduous ecosystems is important for understanding how these exploit the temporally brief and localized rainfall pulses of the North American Monsoon (NAM). Furthermore, quantifying these plant-water relations can help elucidate the spatial patterns of ecohydrological processes at catchment scale in the NAM region. In this effort, we focus on the San Miguel river basin (~ 3500 km2) in Sonora, Mexico, which exhibits seasonal vegetation greening that varies across ecosystems organized along mountain fronts. To assess the spatial variability of ecohydrological conditions, we relied on diverse tools that included multi-temporal remote sensing observations, model-based meteorological forcing, ground-based water and energy flux measurements and hydrologic simulations carried out at multiple scales. We evaluated the impact of seasonal vegetation dynamics on evapotranspiration (ET), its partitioning into soil evaporation (E) and plant transpiration (T), as well as their spatiotemporal patterns over the course of the NAM season. We utilized ground observations of soil moisture and evapotranspiration estimated by the eddy covariance method at two sites, as well as inferences of ET partitioning from stable isotope measurements, to test the numerical simulations. We found that ecosystem phenological differences lead to variations in the time to peak in transpiration during a season and in the overall seasonal ratio of transpiration to evapotranspiration (T/ET). A sensitivity analysis of the numerical simulations revealed that vegetation cover and the soil moisure threshold at which stomata close exert strong controls on the seasonal dominance of transpiration or evaporation. The dynamics of ET and its partitioning are then mapped spatially revealing that mountain front ecosystems utilize water differently. The results of this study aid in understanding how variations in water use and phenological strategies affect how soil water is returned to the atmosphere with implications on the watershed runoff response.

  2. Measuring fallout radionuclides to constrain the origin and the dynamics of suspended sediment in an agricultural drained catchment (Loire River basin, France)

    NASA Astrophysics Data System (ADS)

    Le Gall, Marion; Evrard, Olivier; Foucher, Anthony; Laceby, J. Patrick; Salvador-Blanes, Sébastien; Lefèvre, Irène; Cerdan, Olivier; Ayrault, Sophie

    2015-04-01

    Soil erosion reaches problematic levels in agricultural areas of Northwestern Europe where tile drains may accelerate sediment transfer to rivers. This supply of large quantities of fine sediment to the river network leads to the degradation of water quality by increasing water turbidity, filling reservoirs and transporting contaminants. Agricultural patterns and landscapes features have been largely modified by human activities during the last century. To investigate erosion and sediment transport in lowland drained areas, a small catchment, the Louroux (24 km²), located in the French Loire River basin was selected. In this catchment, channels have been reshaped and more than 220 tile drains outlets have been installed after World War II. As a result, soil erosion and sediment fluxes strongly increased. Sediment supply needs to be better understood by quantifying the contribution of sources and the residence times of particles within the catchment. To this end, a network of river monitoring stations was installed, and fallout radionuclides (Cs-137, excess Pb-210 and Be-7) were measured in rainwater (n=3), drain tile outlets (n=4), suspended sediment (n=15), soil surface (n=30) and channel bank samples (n=15) between January 2013 and February 2014. Cs-137 concentrations were used to quantify the contribution of surface vs. subsurface sources of sediment. Results show a clear dominance of particles originating from surface sources (99 ± 1%). Be-7 and excess Pb-210 concentrations and calculation of Be-7/excess Pb-210 ratios in rainfall and suspended sediment samples were used to estimate percentages of recently eroded sediment in rivers. The first erosive winter storm mainly exported sediment depleted in Be-7 that likely deposited on the riverbed during the previous months. Then, during the subsequent floods, sediment was directly eroded and exported to the catchment outlet. Our results show the added value of combining spatial and temporal tracers to characterize and quantify sources of sediment and particle transport processes within an agricultural catchment.

  3. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Tree Canopy

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the mean percent tree canopy from the Canopy Layer of the National Land Cover Dataset 2001 (LaMotte and Wieczorek, 2010), compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data set represents tree canopy percentage for the conterminous United States for 2001. The Canopy Layer of the National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  4. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Imperviousness

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the mean percent impervious surface from the Imperviousness Layer of the National Land Cover Dataset 2001, (LaMotte and Wieczorek, 2010), compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). The source data set represents imperviousness for the conterminous United States for 2001. The Imperviousness Layer of the National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002;Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  5. Debris-flow frequency and dynamics of an Alpine catchment during the past 150 years, the Schimbrig drainage basin, Central Switzerland

    NASA Astrophysics Data System (ADS)

    Savi, Sara; Bollschweiler, Michelle; Stoffel, Markus; Schlunegger, Fritz

    2010-05-01

    This paper focuses on links between landsliding and debris-flow activity in a ca. 4 km2-large drainage basin located at the northern foothills of the Central Swiss Alps. Debris-flow frequency of the recent past was reconstructed using dendrogeomorphic methods. In addition, the source area was mapped in detail to assess the spatial distribution of landslides, and to determine the connectivity between hillslopes and the channel network. The geomorphic map indicates that the hillslopes host abundant landslides sourced in Paleogene Flysch and Molasse sandstone-mudstone alternations. Major differences in the landscape architecture between the eastern and western sides were identified. In particular, the eastern segment is characterized by a >300'000 m2 large earth flow (Schimbrig landslide) that is 5-10 m deep. This flow experienced a phase of high slip rates >2m day-1 between September 1994 and May 1995, transferring a total of 350'000 m3 of material. In contrast, the western side is characterized by a network of deeply incised channels (>50 m) bordered by hillslopes that host landslides that generally measure <15'000 m2. On these hillslopes, the downslope transfer of sediment is dominated by soil creep or by rotational and translational slip. The depositional fan at the outlet of the catchment has an approximate size of 50'000 m2. The surface is characterized by levees, lobes and channels and is covered by a conifer forest comprising spruces (Picea abies (L.) Karst.) and firs (Abies alba Mill.). A total of 325 increment cores were sampled from 162 trees obviously influenced by past debris-flow activity. Preliminary analysis of the tree samples indicate that 64% of the tree grew up between 1900 and 2009. 34% of the tree samples showed germination dates between 1800 and 1900, and the remaining 2% of the sampled specimens germinated before 1800. Dendrogeomorphic analyses depict that nearly 50% of the sampled trees were affected by debris-flow activity in the 1990s. This period of high activity might be related to enhanced sediment transfer to the river system in response to the high slip rates of the Schimbrig earth slide between 1994 and 1995. Other periods of enhanced debris-flows activity seem to have occurred around 1960, 1950, 1940 and at the end of 19th century.

  6. Preliminary assessment of the Lago Mercedes discovery, Magallanes Basin, Chile

    SciTech Connect

    Dean, J.S. ); Wilson, J.T.; Mainzer, G.F. ); Escobar, F.; Aguirre, G. )

    1993-02-01

    The Lago Mercedes No. 1 well, spudded January 17, 1991, was positioned to test a seismically defined structural culmination located along a blind thrust near the deep foreland axis of the western magallanes Basin. This fault, which defines the leading edge of Andean-related thrust detachment in the region, is responsible for a trap geometry that is genetically related to, but fundamentally different from the numerous unrooted Tertiary folds in the area. Although the Lower Cretaceous Springhill Formation comprised the primary target, it was anticipated that the geometry of the fold allowed for the possibility of several fractured intervals in the hanging wall, including volcaniclastic rocks of the underlying Jurassic Tobifera [open quotes]basement[close quotes] sequence, recently found to be productive elsewhere on the eastern platform of the basin. During drilling of the well, gas and condensate shows were encountered in numerous horizons. The most surprising of these later proved to be a Permo-Triassic granodiorite underlying the Tobifera. Although relatively widespread on outcrop, this represents the first time a pre-rift intrusive body has been penetrated in the subsurface. All of the hydrocarbon-bearing intervals exhibit minimal matrix porosity but varying degrees of fracturing. Subsequent testing of the well yielded combined flow rates of in excess of 12 MMCFD of rich gas and 1140 BPD of 52 A.P.I. condensate. The most prolific zone corresponds to an intensely fractured and partially weathered interval in the uppermost portion of the intrusive. Additional testing is planned prior to any estimate of recoverable reserves. Nevertheless, this unique accumulation underscored the possibility for nonconventional reservoirs throughout the lightly explored Sub-Andean basin trend, particularly fold-thrust belts which have the potential to [open quotes]create[close quotes] reservoirs and trap geometry simultaneously.

  7. Selected examples of needs for long term pilot areas in Mediterranean catchments: a mountain traditional agricultural system and a large and regulated hydrographic basin in Southern Spain

    NASA Astrophysics Data System (ADS)

    José Polo, María; Herrero, Javier; Millares, Agustín; José Pérez-Palazón, María; Pimentel, Rafael; Aguilar, Cristina; Jurado, Alicia; Contreras, Eva; Gómez-Beas, Raquel; Carpintero, Miriam; Gulliver, Zacarías

    2015-04-01

    Integrated River Basin Management (IRBM) aims at planning water, land and other natural resources for an equitable and sustainable management, also capable of preserving or restoring freshwater ecosystems. Long term series of significant variables at different scales and a sound knowledge of the river basin processes are needed to establish the current state and past&future evolution of the hydrological system, soil use and vegetation distribution, and their social impacts and feedbacks. This is particularly crucial if future scenario analyses are to be performed to assess decision-making processes and adaptive plans. This work highlights the need for an adequate design and development of process-oriented monitoring systems at the basin scale in a decision-making framework. First, the hydrologic monitoring network of the Guadalfeo River Basin, in the southern face of Sierra Nevada Range (Spain), is shown, in a pilot catchment of 1300 km2 in which snow processes in Mediterranean conditions have been studied over the last ten years with a holistic approach. The network development and the main features of the dataset are described together with their use for different scientific and environmental applications; their benefits for assessing social and economic impact in the rural environment are shown from a study case in which the sustainability of ancient channels fed by snowmelt, in use since the XIIIth century for traditional irrigated crops in the mountainous area, was assessed in a future scenarios analyses. Secondly, the standard flow and water quality monitoring networks in the Guadalquivir River Basin, a large (57400 km2) and highly regulated agricultural catchment in southern Spain, are shown, and their strengths and weaknessess for an IRBM framework are analysed. Sediments and selected pollutants are used to trace soil erosion and agricultural/urban exports throughout the catchment, and the final loads to the river estuary in the Atlantic Ocean are assessed for the last 35 years. Both study areas require an integrated monitoring approach for future scenarios assessment, adaptive actions programming, and especially for the follow up of their short and long term effects and required corrections.

  8. Snow Accumulation and Spring Melt Rates of Bogs and Fens in the North Granny Creek Catchment Basin, Hudson Bay Lowlands, Ontario

    NASA Astrophysics Data System (ADS)

    Cook, C. F.; Price, J. S.

    2009-05-01

    The Hudson Bay Lowlands contain one of the most extensive, contiguous peatland complexes in the world. Interlinked patterned peatlands developed in this region because of the cool climate, low-gradient topography and an underlying layer of low conductivity marine sediments. There is currently little research regarding the mechanisms that control runoff and surface water connectivity in this region, especially the functions of different peatland types on runoff production and flow pathways. Runoff generation in these systems is dependent on several factors such as soil and pool storage capacity, snow accumulation and melt rates, and peatland morphometry. Snowmelt accounts for a major portion of total annual runoff in this region and the timing of the melt will determine effective runoff production from a peatland catchment. One of the objectives of this project is to identify the processes and mechanisms that generate spring snowmelt runoff in different peatland types (i.e. bogs and fens) and quantify the relative contribution of each type in a peatland-dominated catchment basin. This research is being conducted in a 30 km2 catchment basin located near the DeBeers Victor diamond mine, located 90 km west of Attawapiskat, Ontario. The North Granny Creek basin is located approximately 3 km from the mine pit and is comprised of several peatland types and forms. The surface hydrology of this area is expected to be affected by groundwater depressurization due to dewatering of the mine pit by deep groundwater pumping wells. Effects of this activity on surface hydrology could possibly include increased soil storage capacity due to drier conditions and decreased melt rates due to reduced inputs of warm groundwater. Surface water connectivity is usually at a maximum in the spring because of a relatively impermeable frost table and low soil storage capacity which reduces infiltration. These effects of melt will not be observed uniformly over the entire catchment because of the differing hydrological properties of peatland types. Fens are expected to experience melt quicker than bogs and will receive and convey most of the runoff waters. Snow survey data from the springs of 2008 and 2009 coupled with stream discharge measurements will be used to determine the characteristics of different peatland types that control snow accumulation, melt rates and runoff production and their respective contributions. Since it is expected that the surface hydrology of this area will change over time because of groundwater depressurization it is important to develop a base line characterization of runoff generation and flowpaths within and between peatland types. An examination of snow accumulation and melt characteristics is necessary in northern peatland complexes to fully understand the response of these environments to changes in hydrology.

  9. Effects of Catchment and Riparian Landscape Setting on Water Chemistry and Seasonal Evolution of Water Quality in the Upper Han River Basin, China

    PubMed Central

    Li, Siyue; Xia, Xiaoling; Tan, Xiang; Zhang, Quanfa

    2013-01-01

    Six-year (20052010) evolution of water chemistry (Cl?, NO3?, SO42?, HCO3?, Na+, K+, Ca2+ and Mg2+) and their interactions with morphological properties (i.e., slope and area), land cover, and hydrological seasonality were examined to identify controlling factors and processes governing patterns of stream water quality in the upper Han River, China. Correlation analysis and stepwise multiple regression models revealed significant correlations between ions (i.e., Cl?, SO42?, Na+ and K+) and land cover (i.e., vegetation and bare land) over the entire catchment in both high- and low-flow periods, and in the buffer zone the correlation was much more stronger in the low-flow period. Catchment with steeper slope (>15) was negatively correlated with major ions, largely due to multicollinearity of basin characteristics. Land cover within the buffer zone explained slightly less of major elements than at catchment scale in the rainy season, whereas in the dry season, land cover along the river networks in particular this within 100 m riparian zone much better explained major elements rather than this over the entire catchment. Anthropogenic land uses (i.e., urban and agriculture) however could not explain water chemical variables, albeit EC, TDS, anthropogenic markers (Cl?, NO3?, SO42), Na+, K+ and Ca2+ significantly increased during 20052010, which was corroborated by principal component analyses (PCA) that indicated anthropogenic inputs. Observations demonstrated much higher solute concentrations in the industrial-polluted river. Our results suggested that seasonal evolution of water quality in combined with spatial analysis at multiple scales should be a vital part of identifying the controls on spatio-temporal patterns of water quality. PMID:23349700

  10. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Land Use and Land Cover

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the estimated area of land use and land cover from the National Land Cover Dataset 2001 (LaMotte, 2008), compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). The source data set represents land use and land cover for the conterminous United States for 2001. The National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering the South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5) and the Pacific Northwest (MRB7) river basins.

  11. Lower Permian Dry Mountain trough, eastern Nevada: preliminary basin analysis

    SciTech Connect

    Schwarz, D.L.; Snyder, W.S.; Spinosa, C.

    1987-08-01

    The Lower Permian Dry Mountain trough (DMT) is one of several basins that developed during the Late Pennsylvanian to Permian along the western edge of the North American continent. A tectonic mechanism has been suggested for the subsidence of the DMT, possibly due to reactivation of the Antler orogenic belt during the waning stages of Ancestral Rocky Mountain deformation. The DMT records marked subsidence with the appearance during the Artinskian (latest Wolfcampian) of a deeper water facies that consists of thin-bedded silty micrites and micritic mudstones rich in radiolarians and sponge spicules, characterized by a relative abundance of ammonoids, and rarer conodonts and Nereites ichnofacies trace fossils. Taxa recovered from a distinctive concretionary horizon at various locations provide an Artinskian datum on which to palinspastically reconstruct the DMT paleogeography. These taxa include ammonoids: Uraloceras, Medlicottia, Marathonites, Crimites, Metalegoceras, properrinitids; and conodonts: Neogondolella bisselli, Sweetognathus whitei, S. behnkeni, and Diplognathodus stevensi. The western margin facies of the DMT consists of Permian Carbon Ridge/Garden Valley Formations. Here, lowermost black Artinskianage euxinic micrites, considered a potential source rock for petroleum generation, are overlain by base-of-slope carbonate apron deposits, which, in turn, are overlain by base-of-slope carbonate apron deposits, which, in turn, are overlain by a thick, eastwardly prograding conglomerate wedge. Seismic profiles across Diamond Valley indicate a 3.0-4.6-km thick Tertiary sequence above the Paleozoic strata.

  12. Effect of Agricultural Practices on Hydrology and Water Chemistry in a Small Irrigated Catchment, Yakima River Basin, Washington

    USGS Publications Warehouse

    McCarthy, Kathleen A.; Johnson, Henry M.

    2009-01-01

    The role of irrigation and artificial drainage in the hydrologic cycle and the transport of solutes in a small agricultural catchment in central Washington's Yakima Valley were explored using hydrologic, chemical, isotopic, age-dating, and mineralogical data from several environmental compartments, including stream water, ground water, overland flow, and streambed pore water. A conceptual understanding of catchment hydrology and solute transport was developed and an inverse end-member mixing analysis was used to further explore the effects of agriculture in this small catchment. The median concentrations of major solutes and nitrates were similar for the single field site and for the catchment outflow site, indicating that the net effects of transport processes for these constituents were similar at both scales. However, concentrations of nutrients were different at the two sites, suggesting that field-scale variations in agricultural practices as well as nearstream and instream biochemical processes are important components of agricultural chemical transformation and transport in this catchment. This work indicates that irrigation coupled with artificial drainage networks may exacerbate the ecological effects of agricultural runoff by increasing direct connectivity between fields and streams and minimizing potentially mitigating effects (denitrification and dilution, for example) of longer subsurface pathways.

  13. Las Vegas Basin Seismic Response Project: Preliminary Results From Seismic Refraction Experiments, Las Vegas, NV.

    NASA Astrophysics Data System (ADS)

    Zaragoza, S. A.; Snelson, C. M.; Harder, S. H.; Kaip, G.; Luke, B.; Buck, B. J.; Hanson, A. D.

    2002-12-01

    In May and September 2002, seismic refraction data were acquired in the Las Vegas basin. Located in the southern Basin and Range province, the cities of Las Vegas, North Las Vegas, and Henderson sit atop a fault-bounded basin with a depth of up to 5 km and basin dimensions of roughly 60 km wide (east-west) by 50 km in length (north-south). Previous isostatic gravity, seismic reflection, and aeromagnetic studies indicate that a series of sub-basins exist beneath the unconsolidated basin fill, with the deepest sub-basin occurring 5 km west of the fault block bounding the eastern edge of the basin (Frenchman Mountain). The basin is significantly deeper along its northern extremity, following the path of the fault block bounding the northern edge of the basin (Las Vegas Valley Shear Zone), and along the western edge of Frenchman Mountain. Recent, paleoseismic studies have indicated that faults in the Las Vegas region have the potential for an earthquake of M6.5 to 7.0. It is estimated that a M6.9 earthquake in the basin could produce about 11 billion dollars in damage and a significant number of deaths and/or injuries. In addition, an equivalent or larger event in the Death Valley fault zone, 150 km distance, would also be devastating to the metropolitan area of approximately 1.5 million residents. Therefore, it is essential to understand the seismic hazard posed to the Las Vegas region. This project is part of a larger collaborative effort to characterize the basin and its response to ground shaking. The University of Nevada, Las Vegas with assistance from the University of Texas at El Paso, students from UNLV and UTEP, volunteers from the community and several students from Centennial High school deployed 432 portable seismic recorders ("Texans") throughout the valley. Shot point locations were located at three quarries in the valley, one to the north, one to the east and one to the southwest. The profiles cross the Las Vegas Valley Shear zone as well as a prominent NW/SE trending step in the basin floor across which the basement drops from 2 to 4 km in depth. In addition, the profiles cross several Quaternary fault scarps, which have recently been identified as tectonic in origin. Preliminary analyses of the seismic refraction data indicate that the basin has an average P-wave velocity of 4.5 km/s and is in agreement with the estimated basin depths from isostatic gravity studies (2 to 5 km depth). Both tomographic inversion and forward modeling techniques are being used to analyze these data. These data will be used to produce a velocity model of the basin and image the basin/bedrock contact. In addition, these data will be integrated into a community model, which is being produced by the Las Vegas Basin Seismic Response working group to further assess the site response of the basin.

  14. Permian Basin, Texas: Volume 1, Text: Final preliminary design report

    SciTech Connect

    Not Available

    1988-01-01

    This report is a description of the preliminary design for an Exploratory Shaft Facility (ESF) at the proposed 49 acre site located 21 miles north of Hereford, Texas in Deaf Smith County. Department of Energy must conduct in situ testing at depth to ascertain the engineering and environmental suitability of the site for further consideration for nuclear waste repository development. The ESF includes the construction of two 12-ft diameter engineered shafts for accessing the bedded salt horizon to conduct in situ tests to ascertain if the site should be considered a candidate site for the first High Level Nuclear Waste Repository. This report includes pertinent engineering drawings for two shafts and all support facilities necessary for shaft construction and testing program operation. Shafts will be constructed by conventional drill-and-blast methods employing ground freezing prior to shaft construction to stabilize the existing groundwater and soil conditions at the site. A watertight liner and seal system will be employed to prevent intermingling of aquifers and provide a stable shaft throughout its design life. 38 refs., 37 figs., 14 tabs.

  15. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Artificial Drainage (1992) and Irrigation (1997)

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the estimated area of artifical drainage for the year 1992 and irrigation types for the year 1997 compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data sets were derived from tabular National Resource Inventory (NRI) data sets created by the National Resources Conservation Service (NRCS, U.S. Department of Agriculture, 1995, 2000). Artificial drainage is defined as subsurface drains and ditches. Irrigation types are defined as gravity and pressure. Subsurface drains are described as conduits, such as corrugated plastic tubing, tile, or pipe, installed beneath the ground surface to collect and/or convey drainage. Surface drainage field ditches are described as graded ditches for collecting excess water. Gravity irrigation source is described as irrigation delivered to the farm and/or field by canals or pipelines open to the atmosphere; and water is distributed by the force of gravity down the field by: (1) A surface irrigation system (border, basin, furrow, corrugation, wild flooding, etc.) or (2) Sub-surface irrigation pipelines or ditches. Pressure irrigation source is described as irrigation delivered to the farm and/or field in pump or elevation-induced pressure pipelines, and water is distributed across the field by: (1) Sprinkle irrigation (center pivot, linear move, traveling gun, side roll, hand move, big gun, or fixed set sprinklers), or (2) Micro irrigation (drip emitters, continuous tube bubblers, micro spray or micro sprinklers). NRI data do not include Federal lands and are thus excluded from this dataset. The tabular data for drainage were spatially apportioned to the National Land Cover Dataset (NLCD, Kerie Hitt, U.S. Geological Survey, written commun., 2005) and the tabular data for irrigation were spatially apportioned to an enhanced version of the National Land Cover Dataset (NLCDe, Nakagaki and others, 2007). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  16. Baseflow and stormflow metal fluxes from two small agricultural catchments in the Coastal Plain of the Chesapeake Bay Basin, United States

    USGS Publications Warehouse

    Miller, C.V.; Foster, G.D.; Majedi, B.F.

    2003-01-01

    Annual yields (fluxes per unit area) of Al, Mn, Fe, Ni, Cd, Pb, Zn, Cu, Cr, Co, As and Se were estimated for two small non-tidal stream catchments on the Eastern Shore of the Chesapeake Bay, United States - a poorly drained dissected-upland watershed in the Nanticoke River Basin, and a well-drained feeder tributary in the lower reaches of the Chester River Basin. Both watersheds are dominated by agriculture. A hydrograph-separation technique was used to determine the baseflow and stormflow components of metal yields, thus providing important insights into the effects of hydrology and climate on the transport of metals. Concentrations of suspended-sediment were used as a less-costly proxy of metal concentrations which are generally associated with particles. Results were compared to other studies in Chesapeake Bay and to general trends in metal concentrations across the United States. The study documented a larger than background yield of Zn and Co from the upper Nanticoke River Basin and possibly enriched concentrations of As, Cd and Se from both the upper Nanticoke River and the Chesterville Branch (a tributary of the lower Chester River). The annual yield of total Zn from the Nanticoke River Basin in 1998 was 18,000 g/km2/a, and was two to three times higher than yields reported from comparable river basins in the region. Concentrations of Cd also were high in both basins when compared to crustal concentrations and to other national data, but were within reasonable agreement with other Chesapeake Bay studies. Thus, Cd may be enriched locally either in natural materials or from agriculture.

  17. Preliminary assessment of tree mortality near F- and H-area seepage basins

    SciTech Connect

    Loehle, C; Gladden, J

    1988-01-28

    A preliminary assessment was conducted to evaluate factors that may have been responsible for the vegetation damage that has occurred in groundwater seeps downslope from the F- and H-area seepage basins. The factors that were considered included altered hydrology, toxicity from hazardous chemical constituents associated with seepage basin operation, and toxicity from non-hazardous constituents associated with basin operation. It was concluded that the observed damage was not likely to have resulted from altered hydrologic conditions or hazardous constituents associated with basin operation. Insufficient information is currently available to determine definitively which of the non-hazardous constituents, alone or in concert, were responsible for the observed vegetation damage. The most likely explanation, however, is that elevated Na, pH, and conductivity is outcropping seep water are responsible for tree mortality. All three of these factors will return to ambient levels over a period of several years when basin operation ceases. Faster remediation can be achieved using lime at the seep line.

  18. A framework of parameter uncertainty analysis based on hydro-catchments: Application of the VIC model to the Gila River basin

    NASA Astrophysics Data System (ADS)

    Jia, L.; Stone, M. C.

    2013-12-01

    The objective of this research was to apply a parameter uncertainty framework based on geographic proximity to the Variable Infiltration Capacity (VIC) model within the Gila River Basin (New Mexico and Arizona, USA). The framework aimed to address the following two questions: (1) What are the effects of hydro-catchment (categorized as humid, semi-humid, and dry) to calibrated parameters? and (2) What is the influence of confidence interval with distributed calibrated parameters based on these hydro-catchment? The implementation allows for a more accurate considering of topographic heterogeneity and the sensitivity of parameter to specific hydrograph period. The framework was applied using the VIC model based on sub-grids and an evaluation of the model performance using an integrated GLUE (generalized likelihood uncertainty estimation) scheme under different sets of parameters within a Monte Carlo framework; not a unique global optimum parameter set for the entire watershed as is traditionally applied with this type of exercise. The modified approach shows promising results and the resulting parameter distributions are substantially different than those obtained through traditional uncertainty approaches.

  19. Estimation of design floods in ungauged catchments using a regional index flood method. A case study of Lake Victoria Basin in Kenya

    NASA Astrophysics Data System (ADS)

    Nobert, Joel; Mugo, Margaret; Gadain, Hussein

    Reliable estimation of flood magnitudes corresponding to required return periods, vital for structural design purposes, is impacted by lack of hydrological data in the study area of Lake Victoria Basin in Kenya. Use of regional information, derived from data at gauged sites and regionalized for use at any location within a homogenous region, would improve the reliability of the design flood estimation. Therefore, the regional index flood method has been applied. Based on data from 14 gauged sites, a delineation of the basin into two homogenous regions was achieved using elevation variation (90-m DEM), spatial annual rainfall pattern and Principal Component Analysis of seasonal rainfall patterns (from 94 rainfall stations). At site annual maximum series were modelled using the Log normal (LN) (3P), Log Logistic Distribution (LLG), Generalized Extreme Value (GEV) and Log Pearson Type 3 (LP3) distributions. The parameters of the distributions were estimated using the method of probability weighted moments. Goodness of fit tests were applied and the GEV was identified as the most appropriate model for each site. Based on the GEV model, flood quantiles were estimated and regional frequency curves derived from the averaged at site growth curves. Using the least squares regression method, relationships were developed between the index flood, which is defined as the Mean Annual Flood (MAF) and catchment characteristics. The relationships indicated area, mean annual rainfall and altitude were the three significant variables that greatly influence the index flood. Thereafter, estimates of flood magnitudes in ungauged catchments within a homogenous region were estimated from the derived equations for index flood and quantiles from the regional curves. These estimates will improve flood risk estimation and to support water management and engineering decisions and actions.

  20. Viking bistatic radar observations of the hellas basin on Mars: preliminary results.

    PubMed

    Simpson, R A; Tyler, G L; Brenkle, J P; Sue, M

    1979-01-01

    Preliminary reduction of Viking bistatic radar data gives root-mean-square surface slopes in the Hellas basin on Mars of about 4 degrees on horizontal scales averaged over 10 centimeters to 100 meters. This roughness decreases slightly with position along the ground track, south to north. The dielectric constant in this area appears to be approximately 3.1, greater than the martian average. These values are characteristic of lunar maria and are similar to those found near the Viking lander site in Chryse with the use of Earth-based radar. PMID:17840509

  1. Analysis of Eocene depositional environments - Preliminary TM and TIMS results, Wind River Basin, Wyoming

    NASA Technical Reports Server (NTRS)

    Stucky, Richard K.; Krishtalka, Leonard; Redline, Andrew D.; Lang, Harold R.

    1987-01-01

    Both Landsat TM and aircraft Thermal IR Multispectral Scanner (TIMS) data have been used to map the lithofacies of the Wind River Basin's Eocene physical and biological environments. Preliminary analyses of these data have furnished maps of a fault contact boundary and a complex network of fluvial ribbon channel sandstones. The synoptic view thereby emerging for Eocene fluvial facies clarifies the relationships of ribbon channel sandstones to fossil-bearing overbank/floodplain facies and certain peleosols. The utility of TM and TIMS data is thereby demonstrated.

  2. Mass balance and decontamination times of Polycyclic Aromatic Hydrocarbons in rural nested catchments of an early industrialized region (Seine River basin, France).

    PubMed

    Gateuille, David; Evrard, Olivier; Lefevre, Irène; Moreau-Guigon, Elodie; Alliot, Fabrice; Chevreuil, Marc; Mouchel, Jean-Marie

    2014-02-01

    Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in soils and their subsequent release in rivers constitute a major environmental and public health problem in industrialized countries. In the Seine River basin (France), some PAHs exceed the target concentrations, and the objectives of good chemical status required by the European Water Framework Directive might not be achieved. This investigation was conducted in an upstream subcatchment where atmospheric fallout (n=42), soil (n=33), river water (n=26) and sediment (n=101) samples were collected during one entire hydrological year. PAH concentrations in atmospheric fallout appeared to vary seasonally and to depend on the distance to urban areas. They varied between 60 ng·L(-1) (in a remote site during autumn) and 2,380 ng·L(-1) (in a built-up area during winter). PAH stocks in soils of the catchment were estimated based on land use, as mean PAH concentrations varied between 110 ng·g(-1) under woodland and 2,120 ng·g(-1) in built-up areas. They ranged from 12 to 220 kg·km(-2). PAH contamination in the aqueous phase of rivers remained homogeneous across the catchment (72 ± 38 ng·L(-1)). In contrast, contamination of suspended solid was heterogeneous depending on hydrological conditions and population density in the drainage area. Moreover, PAH concentrations appeared to be higher in sediment (230-9,210 ng·g(-1)) than in the nearby soils. Annual mass balance calculation conducted at the catchment scale showed that current PAH losses were mainly due to dissipation (biodegradation, photo-oxidation and volatilization) within the catchments (about 80%) whereas exports due to soil erosion and riverine transport appeared to be of minor importance. Based on the calculated fluxes, PAHs appeared to have long decontamination times in soils (40 to 1,850 years) thereby compromising the achievement of legislative targets. Overall, the study highlighted the major role of legacy contamination that supplied the bulk of PAHs that are still found nowadays in the environment. PMID:24176709

  3. The challenges of catchment hydrological modelling in the Himalayan region: a case study from the Dudh Kosi River basin of Eastern Nepal

    NASA Astrophysics Data System (ADS)

    Nepal, Santosh; Bajracharya, Sagar R.; Shea, Joseph; Wahid, Shahriar M.; Shrestha, Arun B.; Flügel, Wolfgang-Albert

    2014-05-01

    Catchment-scale hydrological modelling in the Himalayan region suffers from multiple issues that affect our ability to represent the hydrological dynamics of a river system. Due to a lack of monitoring infrastructure, especially in the high-altitude areas, the spatial distribution of precipitation is essentially unknown. Therefore, the regionalization of precipitation in river basins is a challenging task that has implications in the modelling approach at different levels. This paper explores the uncertainty in modelled discharge using different precipitation input datasets in the glaciated catchment of the Dudh Kosi River basin in Eastern Nepal (3712 km2). The basin hosts some of the world's highest mountain peaks, including Mt Everest. Six precipitation stations, which cover mostly the lowland area of the basin, give a station density of one station per 618 km2. First, we examine precipitation dynamics in the study area based on the observed data. Second, the process-oriented distributed J2000 hydrological model is applied in the Dudh Kosi River basin. Third, the model is run with APHRODITE-(V1003R1), CPC-RFE-(2.0) and TRMM-(V7) precipitation products to compare observed and modelled discharge. Nearly 82% of the precipitation occurs during the monsoon season (June - September), and the limited station observations suggest that there is non-uniform distribution of precipitation in which the underlying topography has a great influence. The maximum precipitation occurred at the station which is located on the middle hills region, followed by the station located at the foothills of the Higher Himalaya. Compared to the observed precipitation, the TRMM product is found to be 7% less than the observed data, whereas the other two products were up to 35% less. The model was applied with the six stations data and the regionalization was carried out using Inverse Distance Weighting (IDW) method to simulate the hydrograph. The model was first applied between 1985-1997 in which the model simulates the hydrograph with a Nash-Sutcliffe efficiency of 0.85, a logarithm Nash-Sutcliffe of 0.93, and a coefficient of determination of 0.85. To apply the model during the recent period (2002-2007) when the rainfall products are available, the model was run with the same parameter sets. With observational inputs, high flows are underestimated for some years between 2002 and 2007. Out of the three products, the TRMM generates a better hydrograph, but Percentage BIAS (PBIAS) is -26%, compared to --17% with observed station data between 2002 and 2007. The APHRODITE and CPC-RFE datasets result in discharges that are underestimated by 47% and 51% respectively. The model results based on the three precipitation products suggest that discharge underestimation is due primarily to precipitation input. The lack of precipitation information brings additional challenges to hydrological modelling in the Himalayan region and future research should focus on precipitation observations and dynamics in high-altitude areas. Key words: Catchment hydrology, Himalayan region, J2000 hydrological model, Precipitation pattern

  4. SUGAR CANE GROWING AND CATTLE GRAZING AS DRIVERS TO WETLAND DEGRADATION IN UGANDA: A case of upper river Ruizi and Iguluibi catchments Lake Victoria basin

    NASA Astrophysics Data System (ADS)

    Nakiyemba Were, Alice; Isabirye, Moses; Mathijs, Erik; Deckers, Jozef; Poesen, Jean

    2010-05-01

    Introduction: This study was conducted with in the framework of the VLIR-OI project with the aim of making contributions to the Diagnosis and Remediation of Land Degradation Processes in the Riparian Zone of Lake Victoria Uganda in view of reducing sediment pollution of the Lake Waters with a special focus on the upper river Ruiz and Iguluibi catchments. The study seeks to investigate Sugarcane growing and cattle grazing as drivers to wetland degradation in light of the current farming systems and practices and their contributions to land degradation and pollution of the Lake Victoria waters. Vegetation especially wetlands improves the resistance to erosion. The removal of riparian vegetation tends to accelerate surface erosion as a result of human activities. Increased erosion with in the catchments due to clearing of wetlands for sugarcane growing and cattle grazing has caused adverse increased sedimentation, degraded the water quality, and reduced the water productivity of the Lake Victoria Basin. Methods: We conducted a qualitative and quantitative study to investigate Sugarcane growing and cattle grazing as drivers to wetland degradation in Uganda in light of the current farming systems and practices and their socio-economic contributions to wetland degradation and pollution of the Lake Victoria waters. Focus group discussions, key informant interviews, semi structured interviews and observations were undertaken with the relevant stakeholders in the community. Results: Findings reveal that in Iguluibi catchment, sugarcane growing is now a major activity indicating land use change since the 1990s. Community members said when planting sugarcane all vegetations including all trees are cut leaving the land bare to allow the tractor to clear the land for cultivation. This has left the land bare without any natural vegetation with increased erosion hence eventually loss of soil fertility and increased sediment pollution to the Lake Victoria waters. As a result of land loosing fertility upland, due to erosion and runoff, most community members have resorted to wetlands for agricultural practices with in the catchment and this has hardly left any natural vegetation to protect the soil and increased runoff to Lake Victoria hence sediment pollution of the lake waters. In the Ruizi catchment, many valleys, the natural vegetation has been cut and the land has been turned into pastureland. The massive expansion of livestock keeping into the low lands mainly covered by wetlands is relatively new (over the last 20 years). Burning of rangelands is a common practice and seasonal swamps are grazed during the dry season This change of land use as far as farming practice is concerned has had a big impact on the water levels of the River Ruizi systems in a number of ways for example: the wetland filter system for sediments and sediment fixed nutrients is compromised; lowering of the water storage capacity of the papyrus swamps as a consequence of drainage, hence surface lowering; river bank erosion of the Ruizi by livestock coming into the river for drinking; pollution of the River Ruizi by livestock defecating into the water while drinking. Due to overstocking of the steep slopes by livestock, the low lands are overgrazed which has resulted in soil erosion, that is, mainly sheet and rill erosion, mass movement below cattle tracks, and stone movement by cattle trampling. The steep slope grazing area has generated substantial runoff, the concentrated flow of which causes gullies that cut through the banana groves. Conclusion Vegetation management of riparian areas especially wetlands in Uganda should conserve and maintain adequate ecological balance of the Lake by reducing on nutrient-loaded fluxes from the riparian zone into the Lake Victoria basin.

  5. Crop yield risk analysis and mitigation of smallholder farmers at quaternary catchment level: Case study of B72A in Olifants river basin, South Africa

    NASA Astrophysics Data System (ADS)

    Magombeyi, Manuel S.; Taigbenu, Akpofure E.

    Currently, Sub-Sahara is experiencing increased frequency of disasters either as floods or droughts which depletes the scarce resources available to sustain increasing populations. Success in preventing food shortages in the African continent can only be achieved by understanding the vulnerability and risk of the majority of smallholder farmers under rainfed and supplementary irrigation coupled with appropriate interventions. Increased frequency of floods, droughts and dry spells pose an increasing threat to the smallholder farmers food security and water resources availability in B72A quaternary catchment of the Olifants river basin in South Africa. This paper links maize crop yield risk and smallholder farmer vulnerability arising from droughts by applying a set of interdisciplinary indicators (physical and socio-economic) encompassing gender and institutional vulnerabilities. For the study area, the return period of droughts and dry spells was 2 years. The growing season for maize crop was 121 days on average. Soil water deficit during critical growth stages may reduce potential yields by up to 62%, depending on the length and severity of the moisture deficit. To minimize grain yield loss and avoid total crop failures from intra-seasonal dry spells, farmers applied supplementary irrigation either from river water or rainwater harvested into small reservoirs. Institutional vulnerability was evidenced by disjointed water management institutions with lack of comprehension of roles of higher level institutions by lower level ones. Women are most hit by droughts as they derived more than 90% of their family income from agriculture activities. An enhanced understanding of the vulnerability and risk exposure will assist in developing technologies and policies that conform to the current livelihood strategies of smallholder, resource-constrained farmers. Development of such knowledge base for a catchment opens avenues for computational modeling of the impacts of different types of disasters under different scenarios.

  6. Sources of uncertainty in climate change impacts on river discharge and groundwater in a headwater catchment of the Upper Nile Basin, Uganda

    NASA Astrophysics Data System (ADS)

    Kingston, D. G.; Taylor, R. G.

    2010-07-01

    The changing availability of freshwater resources is likely to be one of the most important consequences of projected 21st century climate change for both human and natural systems. However, substantial uncertainty remains regarding the precise impacts of climate change on water resources, due in part due to uncertainty in GCM projections of climate change. Here we explore the potential impacts of climate change on freshwater resources in a humid, tropical catchment (the River Mitano) in the Upper Nile Basin of Uganda. Uncertainty associated with GCM structure and climate sensitivity is explored, as well as parameter specification within hydrological models. These aims are achieved by running pattern-scaled output from seven GCMs through a semi-distributed hydrological model of the catchment (developed using SWAT). Importantly, use of pattern-scaled GCM output allows investigation of specific thresholds of global climate change including the purported 2 C threshold of "dangerous" climate change. In-depth analysis of results based on the HadCM3 GCM climate scenarios shows that annual river discharge first increases, then declines with rising global mean air temperature. A coincidental shift from a bimodal to unimodal discharge regime also results from a projected reduction in baseflow (groundwater discharge). Both of these changes occur after a 4 C rise in global mean air temperature. These results are, however, highly GCM dependent, in both the magnitude and direction of change. This dependence stems primarily from projected differences in GCM scenario precipitation rather than temperature. GCM-related uncertainty is far greater than that associated with climate sensitivity or hydrological model parameterisation.

  7. SPATIAL VARIABILITY OF DRY SPELLS A spatial and temporal rainfall analysis of the Pangani basin and Makanya catchment, Tanzania

    NASA Astrophysics Data System (ADS)

    Fischer, B. M. C.; Savenije, H. H. G. H. H. G.

    2009-04-01

    Rainfall and soil moisture are key parameters for food production and which are spatial and temporal variable. In a ever growing world the stress on water for food production increases. Farmers especially in semi arid regions with rain fed agriculture are more often forced to make away from "A" locations where water is available to water scares "B" or worse locations. Obliged by availability of arable land, tradition, customs, natural 6th sense or farmers cleverness. To improve agricultural yields a better water resource planning ,supported by system knowledge, is needed. This study describes a Markov bases dry spell tool which can fulfil in this need. By making use of Markov properties of rainfall, the temporal variability has been analysed. Plotting the derived seasonal transition probabilities vs. the rainfall amount a spatial variable power function could be derived. The spatial and temporal knowledge of rainfall was combined in the Markov based dry spell tool. For a given probability the tool provides a dry spell map. The dry spell tool is a powerful tool to assess vulnerability of dry spells based on meteorological data. The meteorological dry spell in combination with the agricultural dry spell length or critical dry spell length, which is determined by soil and vegetation characteristics, risk maps of an area to the vulnerability of dry spells could be made. The tool was applied in a case study in the Makanya catchment and showed: Compared to the lower middle part of the catchment, high altitude parts of the catchment receive higher amounts of rainfall, have shorter meteorological dry spells and are more resilient to dry spells due to their soil and vegetation characteristics. As a result one can state that farmers living in mountainous areas are blessed by their location. They receive more rain and have lower probability of long dry spells, higher probability of crop success and a higher probability of high yields, in contrast to the farmers in the valley. However, the latter have a chance at making a living as well. The opportunity is, next to the more traditional water management strategies (improving irrigation etc.), to develop new water management strategies (rainwater harvesting, improvement of soil characteristics and decrease of transpiration fluxes) to bridge or decrease the vulnerability of meteorological dry spells.

  8. Preliminary use of compound-specific stable isotope (CSSI) technique to identify and apportion sediment origin in a small Austrian catchment

    NASA Astrophysics Data System (ADS)

    Mabit, Lionel; Gibbs, Max; Chen, Xu; Meusburger, Katrin; Toloza, Arsenio; Resch, Christian; Klik, Andreas; Eder, Alexander; Strauss, Peter; Alewell, Christine

    2015-04-01

    The overall impacts of climate change on agriculture are expected to be negative, threatening global food security. In the agricultural areas of the European Union, water erosion risk is expected to increase by about 80% by the year 2050. Reducing soil erosion and sedimentation-related environmental problems represent a key requirement for mitigating the impact of climate change. A new forensic stable isotope technique, using the compound specific stable isotope (CSSI) signatures of inherent soil organic biomarkers, can discriminate and apportion the source soil contribution from different land uses. Plant communities label the soil where they grow by exuding organic biomarkers. Although all plants produce the same biomarkers, the stable isotopic signature of those biomarkers is different for each plant species. For agri-environmental investigation, the CSSI technique is based on the measurement of carbon-13 (13-C) natural abundance signatures of specific organic compounds such as natural fatty acids (FAs) in the soil. By linking fingerprints of land use to the sediment in deposition zones, this approach has been shown to be a useful technique for determining the source of eroded soil and thereby identifying areas prone to soil degradation. The authors have tested this innovative stable isotopic approach in a small Austrian agricultural catchment located 60 km north of Vienna. A previous fallout radionuclide (i.e. 137-Cs) based investigation established a sedimentation rate of 4 mm/yr in the lowest part of the study site. To gain knowledge about the origin of these sediments, the CSSI technique was then tested using representative samples from the different land-uses of the catchment as source material. Values of 13-C signatures of specific FAs (i.e. C22:0 = Behenic Acid ; C24:0 = Lignoceric Acid) and the bulk 13-C of the sediment mixture and potential landscape sources were analyzed with the mixing models IsoSource and CSSIAR v1.00. Using both mixing models, preliminary results highlighted that about 50-55% of the sediment located in the deposition area originated from the main grassed waterway of the catchment.

  9. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Nutrient Inputs from Fertilizer and Manure, Nitrogen and Phosphorus (N&P), 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the total amount of nitrogen and phosphorus, in kilograms for the year 2002, compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). The source data set is County-Level Estimates of Nutrient Inputs to the Land Surface of the Conterminous United States, 1982-2001 (Ruddy and others, 2006). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  10. Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Nutrient Application (Phosphorus and Nitrogen) for Fertilizer and Manure Applied to Crops (Cropsplit), 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the estimated amount of phosphorus and nitrogen fertilizers applied to selected crops for the year 2002, compiled for every MRB_E2RF1 catchment of Major River Basins (MRBs, Crawford and others, 2006). The source data set is based on 2002 fertilizer data (Ruddy and others, 2006) and tabulated by crop type per county (Alexander and others, 2007). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for MRB_E2RF1 catchments for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

  11. Preliminary study of phosphorus runoff and drainage from a paddy field in the Taihu Basin.

    PubMed

    Zuo, Qiang; Lu, C A; Zhang, W L

    2003-02-01

    An investigation into phosphorus runoff and drainage from a paddy field was carried out at Changshu Agricultural Ecological Station of CAS during the year 2000. According to the preliminary study, some results indicated: (1) Total phosphorus (TP) content of regular irrigation water was 19 times higher than TP content of P0 (zero rate of P fertilization) stand water. This indicates that paddy fields are a potential source of phosphorus pollution by runoff and drainage into the Taihu Lake Basin (TLB); (2) During the first 10 days after phosphate fertilizer application, the TP concentration of stand water in the paddy field was very high, therefore this was the high risk period for Taihu Lake phosphorus contamination; (3) Four mathematical models of P losses from a paddy field in the TLB are developed. These are based on data for the year 2000, but they will be improved as more data is acquired in future years. PMID:12688477

  12. Impact of Urbanization on Stormwater Runoff from a Small Urban Catchment: Gda?sk Ma?omiejska Basin Case Study

    NASA Astrophysics Data System (ADS)

    Olechnowicz, Borys; Weinerowska-Bords, Katarzyna

    2014-12-01

    This paper deals with the impact of different forms of urbanization on the basin outflow. The influence of changes in land cover/use, drainage system development, reservoirs, and alternative ways of stormwater management (green roofs, permeable pavements) on basin runoff was presented in the case of a small urban basin in Gdansk (Poland). Seven variants of area development (in the period of 2000-2012) - three historical and four hypothetical - were analyzed. In each case, runoff calculations for three rainfall scenarios were carried out by means of the Hydrologic Modeling System designed by Hydrologic Engineering Center of the U.S. Army Corps of Engineers (HEC-HMS). The Soil Conservation Service (SCS) Curve Number (CN) method was used for calculations of effective rainfall, the kinematic wave model for those of overland flow, and the Muskingum-Cunge model for those of channel routing. The calculations indicated that urban development had resulted in increased peak discharge and runoff volume and in decreased peak time. On the other hand, a significant reduction in peak values was observed for a relatively small decrease in the normal storage level (NSL) in reservoirs or when green roofs on commercial centers were present. The study confirmed a significant increase in runoff as a result of urbanization and a considerable runoff reduction by simple alternative ways of stormwater management.

  13. From the Highest to the Deepest: A River-Sea Dispersal System that Links A Mountainous Catchment to the Deep-Sea Basin (Invited)

    NASA Astrophysics Data System (ADS)

    Liu, J. T.; Hsu, R. T.

    2013-12-01

    Gaoping River (GPR) is a small mountainous river whose source area is located in the southern Central Range of Taiwan, about 3900 m above sea level. It has an average gradient of 1:150. Both the chemical and physical weathering rates for the GPR catchment are higher than the world average. Approximately 1 km seaward from the mouth of the GPR is the head of the Gaoping Submarine Canyon (GPSC). GPR annually discharges 35 Mt of sediment into the sea, most of which enters the GPSC. The GPSC owes its existence to tectonic processes related to the collision of the Philippine Plate and the Eurasia Plate. The canyon extents from the mouth of GPR, cutting through the Gaoping shelf and slope, and merges into the northeastern Manila Trench over a distance of about 260 km in water depth over 3000 m. It is a major conduit for the transport of terrestrial sediment to the South China Sea (SCS) and the landward transport of particles of marine origin in the SCS. The thickness of the tidally-dominated benthic nepheloid layer (BNL) in the GPSC can exceed 200 m, in which the temperature, flow, and suspended sediment concentration show distinctive tidal oscillations. Both semidiruanl barotropic and baroclinic tides are important in the canyon. In the GRSC the normal transport of suspended sediment associated with tidal propagation from offshore is up-canyon yet episodic sediment transports associated with episodic gravity-driven events are down-canyon. Typhoon-induced river floods often ignite turbidity currents (TCs) in the GPSC. Therefore, hperpycnal river plume and the ensuing TCs form an effective pathway to transport large amount of terrestrial sediment and carbon (fresh and aged) to the SCS basin. However, due to the extensive disturbance in the GPR catchment by typhoon-related deep erosion of hillslopes and incision of river channels, the ';fresh' flood sediment exported by GPR during and immediately after typhoons contains old sediment as defined by the absence of 7Be. Consequently, a new paradigm is proposed that ';fresh sediments exported from highly disturbed catchments during floods are old sediments'. The upper reaches of the canyon act as a sink for coarser TC deposits (turbidites). Finer turbidites are abundant in the middle and lower reaches. These findings also suggest rapid transport of fluvial sediment from the GPR down the GPSC, delivered by hyperpycnal TCs. Earthquake-triggered episodic gravity flows are also important transport agents of reworked marine sediment in the GPSC. The GPR-GPSC represents a type of source-to-sink systems in which terrestrial sediment in a mountainous catchment is promptly removed and transported to the river mouth by fluvial processes, and then efficiently and quickly transported to the deep-sea by turbidity currents along a submarine conduit during episodic typhoon events. This is also a pathway by which fresh terrestrial carbon could be quickly and effectively delivered to the deep-sea with little oxidation, which is a substantial step in the sequestration of carbon.

  14. Preliminary hydrologic budget studies, Indian Creek watershed and vicinity, Western Paradox Basin, Utah

    SciTech Connect

    Thackston, J.W.; Mangarella, P.A.; Preslo, L.M.

    1986-05-01

    Preliminary quantitative estimates of ground-water discharge into the Colorado River System in the western Paradox Basin were prepared on the basis of existing climatological and streamflow records. Ground-water outflow to the river was deduced as a residual from hydrologic budget equations for two different study areas: (1) the region between gaging stations at Cisco, Green River, and Hite, Utah; and (2) the Indian Creek watershed. An empirical correlation between recharge rates and precipitation amounts derived for several basins in eastern Nevada was applied to estimate recharge amounts for the Indian Creek watershed. A simple Darcian flow model was then used to approximate the ground-water flux outward from the watershed for comparison. Salinity measurements in the Colorado River were also used to approximate ground-water outflow to a river reach in Cataract Canyon in order to provide another comparison with the hydrologic budget results. Although these estimates should be considered only gross approximations, all approaches used provide values of ground-water outflow that are much less than estimates of similar parameters provided by the US Geological Survey in recent hydrologic reconnaissance reports. Estimates contained herein will be refined in future numerical modeling and data collection studies.

  15. Preliminary Simulations of CO2 Transport in the Dolostone Formations in the Ordos Basin, China

    SciTech Connect

    Hao, Y; Wolery, T; Carroll, S

    2009-04-30

    This report summarizes preliminary 2-D reactive-transport simulations on the injection, storage and transport of supercritical CO{sub 2} in dolostone formations in the Ordos Basin in China. The purpose of the simulations was to evaluate the role that basin heterogeneity, permeability, CO{sub 2} flux, and geochemical reactions between the carbonate geology and the CO{sub 2} equilibrated brines have on the evolution of porosity and permeability in the storage reservoir. The 2-D simulation of CO{sub 2} injection at 10{sup 3} ton/year corresponds to CO{sub 2} injection at a rate of 3 x 10{sup 5} ton/year in a 3-D, low permeable rock. An average permeability of 10 md was used in the simulation and reflects the upper range of permeability reported for the Ordos Basin Majiagou Group. Transport and distribution of CO{sub 2} between in the gas, aqueous, and solid phases were followed during a 10-year injection phase and a 10-year post injection phase. Our results show that CO{sub 2} flux and the spatial distribution of reservoir permeability will dictate the transport of CO{sub 2} in the injection and post injection phases. The injection rate of supercritical CO{sub 2} into low permeable reservoirs may need to be adjusted to avoid over pressure and mechanical damage to the reservoir. Although it should be noted that 3-D simulations are needed to more accurately model pressure build-up in the injection phase. There is negligible change in porosity and permeability due to carbonate mineral dissolution or anhydrite precipitation because a very small amount of carbonate dissolution is required to reach equilibrium with respect these phases. Injected CO{sub 2} is stored largely in supercritical and dissolved phases. During the injection phase, CO{sub 2} is transport driven by pressure build up and CO{sub 2} buoyancy.

  16. Drainage Basin Erosion Rates Along the Death Valley Fault Zone, California From In-Situ Cosmogenic 14C in Alluvial Sediment: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Frankel, K. L.; Pigati, J. S.; Hoeft, J. S.; Lifton, N. A.; Dolan, J. F.

    2004-12-01

    Catchment-wide erosion rates and drainage basin evolution are poorly understood processes in arid and hyper-arid climates. We collected samples from two small catchments in Death Valley, CA to determine basin-wide erosion rates using in-situ cosmogenic 14C to help understand drainage development in a hyper-arid setting. Death Valley is a tectonically active pull-apart system with a normal fault-bounded basin in the center and strike-slip faults to the north and south. On average, the area receives < 5 cm of precipitation per year. Two basins were sampled from different parts of the fault zone; one along the normal fault-bounded segment in the Black Mountains and one from the southern strike-slip segment in the Owlshead Mountains. Topography along the dip-slip segment of the fault zone in the Black Mountains is youthful with steep, high relief catchments, triangular facets, and young fault scarps at the base of the range. Drainage basins in the Black Mountains have high ratios of basin excavated volume to planimetric area and high first-order stream gradients. Additionally, basins formed along the normal fault-bounded segment typically have large, 10-20 m high knickpoints and highly convex channel profiles. In contrast, the Owlshead Mountains are relatively low relief, and appear to be in a state of topographic decay. Samples were collected above and below a 20 m high knickpoint in the Badwater catchment, above and below a smaller (5 m high) knickzone in the Owlshead Mountains, and at the mouths of both catchments. In-situ 14C can be used to determine erosion rates in rapidly denuding areas that are integrated over a period of several thousand years. We are particularly interested in post-last glacial maximum erosion rates, which could be a function of climate change and the drying up of glacial Lake Manly, relative base-level fall resulting from recent movement on the fault zone, or a combination of both. Previous studies have shown that climate change since the last glacial maximum appears to have had little or no effect on erosion rates in eastern California. Because of this, drainage basin erosion rates may express a link between ground-rupturing earthquake activity on the Death Valley fault zone and denudation. The catchment-wide erosion rates may also help characterize fault zone segmentation, in conjunction with paleoseismologic, slip rate, and topographic metrics data.

  17. REACH-ER: a tool to evaluate river basin remediation measures for contaminants at the catchment scale

    NASA Astrophysics Data System (ADS)

    van Griensven, Ann; Haest, Pieter Jan; Broekx, Steven; Seuntjens, Piet; Campling, Paul; Ducos, Geraldine; Blaha, Ludek; Slobodnik, Jaroslav

    2010-05-01

    The European Union (EU) adopted the Water Framework Directive (WFD) in 2000 ensuring that all aquatic ecosystems meet good status' by 2015. However, it is a major challenge for river basin managers to meet this requirement in river basins with a high population density as well as intensive agricultural and industrial activities. The EU financed AQUAREHAB project (FP7) specifically examines the ecological and economic impact of innovative rehabilitation technologies for multi-pressured degraded water bodies. For this purpose, a generic collaborative management tool REACH-ER' is being developed that can be used by stakeholders, citizens and water managers to evaluate the ecological and economical effects of different remedial actions on waterbodies. The tool is built using databases from large scale models simulating the hydrological dynamics of the river basing and sub-basins, the costs of the measures and the effectiveness of the measures in terms of ecological impact. Knowledge rules are used to describe the relationships between these data in order to compute the flux concentrations or to compute the effectiveness of measures. The management tool specifically addresses nitrate pollution and pollution by organic micropollutants. Detailed models are also used to predict the effectiveness of site remedial technologies using readily available global data. Rules describing ecological impacts are derived from ecotoxicological data for (mixtures of) specific contaminants (msPAF) and ecological indices relating effects to the presence of certain contaminants. Rules describing the cost-effectiveness of measures are derived from linear programming models identifying the least-cost combination of abatement measures to satisfy multi-pollutant reduction targets and from multi-criteria analysis.

  18. Congo Basin Streamflow characterization using multi-source satellite-derived data: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Munzimi, Y.; Hansen, M. C.; Asante, K. O.

    2010-12-01

    The Congo Basin in Central Africa has the second largest discharge of any river system, second only to the Amazon Basin. As such, it is considered a potential and strategic asset for supplying not only fresh water but also clean energy through hydropower generation. However, very little of Congo River Basin hydrology is known. Indeed, the basin hydrometeorological network is deteriorating and has a small number of gauges unevenly distributed throughout the Congo watershed. In such cases where in situ data are scarce, remote sensing can be used to quantify rainfall pattern and river flow regime. In default of contributing to quantification exercises, limited ground data available can be used for validation work. To better understand hydrological processes in the Congo River Basin, a 2009 NASA funded project entitled Hydrological Response to Land Cover and Land Use Change in the Congo Basin exploits remote sensing capabilities coupled with large scale hydrological modeling. Temporal and terrestrial satellite-based data are ingested into the USGS Geospatial Streamflow Model (GeoSFM) for daily flow generation. The reliance on remotely sensed data to replace or supplement ground data for this hydrological application necessitates rigorous validation of these products. As TRMM Satellite rainfall estimates are being used in this study in place of gauge observations, ground precipitation data reported in existing nationally-held datasets from 33 meteorological stations are used for validation purposes. Initial research on the Congo Basin compared streamflow estimated with GeoSFM against available current and historical streamflow data. While initial results were promising, some discrepancies were revealed, attributed to the accuracy of the input data and the non-calibration of the model. A key finding was that the existing parameterization of land cover using coarse resolution data is inadequate to accurately characterize rainfall-runoff processes in the Congo. As part of the NASA project, the important question of improving the agreement between modeled flows from satellite-derived data and observed flow data from hydrometric field stations is addressed. To evaluate the GeoSFM performance, the model is run using coarse resolution (Land Cover Land Use) LCLU and DEM inputs and then using improved region-specific high spatial resolution inputs. Intercomparisons are made to evaluate improvement to streamflow characterization based on improved input data. Improved streamflow is a key for establishing the setting for a high-performance calibration process for the Congo. Changing the parameter values used in the model until a satisfactory agreement between simulated and the recorded variables is obtained is an integral part of modeling. However, in order to produce realistic parameters values and a sufficiently calibrated model, the calibration requires the finest baseline simulated streamflow data possible. A poster will present our preliminary results.

  19. Long-term integrated river basin planning and management of water quantity and water quality in mining impacted catchments

    NASA Astrophysics Data System (ADS)

    Pohle, Ina; Zimmermann, Kai; Claus, Thomas; Koch, Hagen; Gädeke, Anne; Uhlmann, Wilfried; Kaltofen, Michael; Müller, Fabian; Redetzky, Michael; Schramm, Martina; Schoenheinz, Dagmar; Grünewald, Uwe

    2015-04-01

    During the last decades, socioeconomic change in the catchment of the Spree River, a tributary of the Elbe, has been to a large extent associated with lignite mining activities and the rapid decrease of these activities in the 1990s. There are multiple interconnections between lignite mining and water management both in terms of water quantity and quality. During the active mining period a large-scale groundwater depression cone has been formed while river discharges have been artificially increased. Now, the decommissioned opencast mines are being transformed into Europe's largest man-made lake district. However, acid mine drainage causes low pH in post mining lakes and high concentrations of iron and sulphate in post mining lakes and the river system. Next to potential changes in mining activities, also the potential impacts of climate change (increasing temperature and decreasing precipitation) on water resources of the region are of major interest. The fundamental question is to what extent problems in terms of water quantity and water quality are exacerbated and whether they can be mitigated by adaptation measures. In consequence, long term water resource planning in the region has to formulate adaptation measures to climate change and socioeconomic change in terms of mining activities which consider both, water quantity and water quality aspects. To assess potential impacts of climate and socioeconomic change on water quantity and water quality of the Spree River catchment up to the Spremberg reservoir in the scenario period up to 2052, we used a model chain which consists of (i) the regional climate model STAR (scenarios with a further increase in temperature of 0 and 2 K), (ii) mining scenarios (mining discharges, cooling water consumption of thermal power plants), (iii) the ecohydrological model SWIM (natural water balance), (iv) the long term water management model WBalMo (managed discharges, withdrawal of water users, reservoir operation) and (v) the water quality model GGM (mining related water quality parameters of lakes and river reaches). Based on the STAR 0K scenario, only minor changes in the natural water balance are simulated, while managed discharges slightly decrease due to declining mining discharges. In the STAR 2K scenario natural and managed discharges decrease resulting in negative consequences on reservoir volumes and on water availability to the users. Additionally, the risk of a re-acidification of mining lakes and increasing sulphate and iron concentrations is much higher in the STAR 2K scenario than in the STAR 0K scenario. In order to compensate for negative impacts on water quantity and water quality, adaptation measures were analysed. While water transfers from the River Elbe into the study region showed positive impacts on both, water quantity and water quality, potentially negative impacts on water quality can also be compensated by technical measures (e.g. in-lake-neutralisation of mining lakes).

  20. Spatial and temporal variations of herbicide (triazines and phenylureas) concentrations in the catchment basin of the Marne river (France).

    PubMed

    Garmouma, M; Teil, M J; Blanchard, M; Chevreuil, M

    1998-12-11

    Triazine and phenylurea concentrations were investigated in four sub-basins of the Marne river (France) in 1992 and 1993. The peak concentrations of atrazine, simazine and isoproturon occurred between March and July. In the four basins, the peaks were in relation with the herbicide application periods and with the important rainfalls, except for the isoproturon. The peaks of terbutryne and ametryne came later in the year, due to their use for weed control on post-emergent corn. For the phenylureas, the peak concentrations were observed in March-April next to the spraying period on winter cereals. The fast transfer of those herbicides was related to their high water solubility. In all the samples, the deethylatrazine (DEA) was detected 1 month after the atrazine due to its degradation within the soils which is of minor importance as compared to its transport by surface waters and also, to interactions between the silt sheet and the stream itself. The DAR evolution showed that the atrazine residence time depends both on the run-off in the first centimetres of the soil and on the treatment periods, particularly in the Grand Morin. The Marne river contamination level was similar to that of the Mlarchez and of the Grand Morin. The minor pollution of the Orgeval was related to minor cultivated areas. PMID:9926428

  1. Quantification of water and sediment yield from small catchment in open mining areas: experience and results from Poro nickel mining basin in New Caledonia

    NASA Astrophysics Data System (ADS)

    Mathys, Nicolle; Allenbach, Michel; Wottling, Geoffroy; Carpentier, Laureen; Freydier, Perrine; Navarrot, Lucie

    2014-05-01

    Water management in mining environments is a major challenge of the mining projects. In New Caledonia large areas have been excavated for Nickel mining since the end of the 19th century. In the past, the bad management of the water and coarse sediments left scars in the landscape and management problems in the channel reaches downstream. Nowadays, open mining techniques no longer yield coarse material out of the mining areas but the management of water and fine sediment remains a difficult question as the suspended sediments reach the very fragile environment of the lagoon. In addition, in many areas, it threatens human activities in the downstream rivers. In order to quantify and understand the formation of runoff, erosion and sediment transport in small mining watersheds the "Hydromine" project was initiated in 2008 by the New Caledonia government (DAVAR) with the collaboration of the University of New Caledonia (UNC) and later with the scientific support of Irstea Grenoble. The questions addressed by this project are: - What is the response (water and sediments) of a mining watershed to a rainfall input? - What factors control this response? - What are the processes involved? And which are dominant in the various hydrometeorological situations? - What are the characteristics of the transported materials? - What is the efficiency of mitigation works in the mining area? Two small embedded catchments (0.09 and 0.30 km) are monitored for measuring rainfall, runoff and fine sediment transport in the mining area of Poro, East cost of New Caledonia. Elevation ranges from 197 to 366 m.a.s.l. The slope are steep (36 % in average but locally up to 130%) and the vegetation cover is very low (20% for the larger basin, 0% for the headwater basin). Rainfall-runoff and discharge-sediment concentration (SSC) relationship were analysed at the event and annual time scale. As a result, we pointed out the main factors that influence the response of the basins to a rainfall event: rainfall depth, rainfall intensity in fifteen minutes and in two hours, peak discharge, runoff coefficient, dry time duration before the event and flood duration. The calculation of suspended sediment yield (SSY) at different time scales gives an evaluation of the pollution delivered to the creeks and lagoon and of the water management and sediment trap efficiency. An extreme rainfall event (December 25th, 2011) of 500 mm in 26 hours yielded downstream more suspended sediment than all the floods of the previous monitored period. This highlights the threshold effects in runoff and erosion response in these open mining areas.

  2. Preliminary study on soil to rock spectral ratio method of microtremor measurement in Taipei Basin, Taiwan

    NASA Astrophysics Data System (ADS)

    Huang, Jyun Yan; Wen, Kuo Liang; Te Chen, Chun; Chang, Shun Chiang

    2014-05-01

    Taipei city is the capital of Taiwan which located in Taipei basin and covered with hundreds meter of alluvial layer that might cause serious damage during huge earthquake. Prediction of possible strong motion levels occurred in the basin then became popular. Engineers most like to use Ground Motion Prediction Equation (GMPEs) as common tool for seismic hazard calculation but GMPEs were usually debated that it can only give one prediction value (PGA, PGV, Sa etc.) rather than time history or spectrum. Seismologists tried theoretical simulation (1D, 2D, 3D method) but could only give low frequency (usually less than 1 Hz) results restricted to that the shallow structures were not clear enough. Resent years, wide frequency simulation techniques such as empirical green's function added stochastic simulation method (hybrid method) were applied to several different purposes but site effect still plays an important role that need to be considered. Traditionally soil to rock spectral ratio of shear wave (denoted as S/R) was widely applied to check basin effect for decades but the technique needs lots of permanent stations and several years to get enough records. If some site located within strong motion network but not close enough to the strong motion stations, interpolate or extrapolate results needed to be used. Wen and Huang (2012) conducted a dense microtremor measurement network in whole Taiwan and applied microtremor H/V to discuss dominant frequency with traditional transfer functions from earthquake shear wave and found good agreement between them. Furthermore, in this study, the ability of soil to rock spectral ratio of microtremor (denoted as MS/R) measurement was tested in Taipei basin. The preliminary results showed MS/R had good agreement with S/R between 0.2 to 5 Hz. And distance from soil site to reference rock site should no greater than 8 to 10 km base on degree of spectrum difference (DSPD) calculation. If the MS/R works that site effect study from this technique could be applied for some region which distribution of strong motion stations were not dense enough after all.

  3. Video monitoring in the Gadria debris flow catchment: preliminary results of large scale particle image velocimetry (LSPIV)

    NASA Astrophysics Data System (ADS)

    Theule, Joshua; Crema, Stefano; Comiti, Francesco; Cavalli, Marco; Marchi, Lorenzo

    2015-04-01

    Large scale particle image velocimetry (LSPIV) is a technique mostly used in rivers to measure two dimensional velocities from high resolution images at high frame rates. This technique still needs to be thoroughly explored in the field of debris flow studies. The Gadria debris flow monitoring catchment in Val Venosta (Italian Alps) has been equipped with four MOBOTIX M12 video cameras. Two cameras are located in a sediment trap located close to the alluvial fan apex, one looking upstream and the other looking down and more perpendicular to the flow. The third camera is in the next reach upstream from the sediment trap at a closer proximity to the flow. These three cameras are connected to a field shelter equipped with power supply and a server collecting all the monitoring data. The fourth camera is located in an active gully, the camera is activated by a rain gauge when there is one minute of rainfall. Before LSPIV can be used, the highly distorted images need to be corrected and accurate reference points need to be made. We decided to use IMGRAFT (an opensource image georectification toolbox) which can correct distorted images using reference points and camera location, and then finally rectifies the batch of images onto a DEM grid (or the DEM grid onto the image coordinates). With the orthorectified images, we used the freeware Fudaa-LSPIV (developed by EDF, IRSTEA, and DeltaCAD Company) to generate the LSPIV calculations of the flow events. Calculated velocities can easily be checked manually because of the already orthorectified images. During the monitoring program (since 2011) we recorded three debris flow events at the sediment trap area (each with very different surge dynamics). The camera in the gully was in operation in 2014 which managed to record granular flows and rockfalls, which particle tracking may be more appropriate for velocity measurements. The four cameras allows us to explore the limitations of camera distance, angle, frame rate, and image quality.

  4. Impact of altitudinal variability on streamflows in mountainous catchments under changing climate (Upper Indus Basin), Himalayas Pakistan

    NASA Astrophysics Data System (ADS)

    Khan, K. M.; Yaseen, M.

    2014-12-01

    Pakistan's economy is based on agriculture that is highly dependent on water resources originating in the mountain sources of the Upper Indus Basin (UIB). Various rivers i.e. Chitral, Swat, Kabul, Hunza, Gilgit, Astore, Shigar, Shyok & tributaries contribute water to main Indus River. The elevation of UIB ranges from 254 m to 8570 m a.m.s.l. Changes in climate and related hydrological impacts vary in space and time as affected by local climatic and topographic settings. So, the objective of this study was to assess the climate change and related hydrological impacts resulting from altitudinal variability. Trend analyses were performed by applying Mann-Kendall and Sen's method was applied to estimate slope time series that indicates changes in river flows. The results of this study indicate that maximum temperature in annual, winter, spring and autumn seasons has increased with increased in altitude while annual, winter and autumn minimum temperature has decreased with increased in altitude for the period (1961-2011). Moreover, annual, winter, summer and autumn precipitation has been decreased. The impact of altitudinal variability under changing climate yields that annual and seasonal streamflows in River Indus (at Kharmong, Alam Br. and Khairabad), Sawat (at Kalam) and Kabul (at Nowshera) have decreased whereas in River Shoyk (9%), Shigar (7%) and Indus at Kachura (5%) have been increased. However, annual runoff in Gilgit (1%) and Hunza River (18%) has increased by increasing 2 % annual temperature. A seasonal correlation coefficient between temperature and streamflow has the positive correlation in most of the sub-basins of UIB for both spring and summer. With increased 1 oC temperature in spring yields increased streamflow for rives Gilgit, Chitral, Astore, Shoyk, Shigar, Indus at Kachura & Kharmong and Hunza with percentage of 19, 5, 11, 15, 9, 7, 1 and 12 respectively. The prevailing trends and variability, caused by climate change, have an effect on the flows that should be considered by the water managers for better water management in a water scarcity country like Pakistan. On the basis of collected real time data, an awareness regarding present Integrated Water Management (IWM) working with up-to-date techniques is recommended for effective water on-going reform process.

  5. Preliminary seismicity and focal mechanisms for the southern Great Basin of Nevada and California: January 1992 through September 1992

    SciTech Connect

    Harmsen, S.C.

    1994-06-01

    The telemetered southern Great Basin seismic network (SGBSN) is operated for the Department of Energy`s Yucca Mountain Project (YMP). The US Geological Survey, Branch of Earthquake and Landslide Hazards, maintained this network until September 30, 1992, at which time all operational and analysis responsibilities were transferred to the University of Nevada at Reno Seismological Laboratory (UNRSL). This report contains preliminary earthquake and chemical explosion hypocenter listings and preliminary earthquake focal mechanism solutions for USGS/SGBSN data for the period January 1, 1992 through September 30, 1992, 15:00 UTC.

  6. Statistical downscaling and projection of future temperature and precipitation change in middle catchment of Sutlej River Basin, India

    NASA Astrophysics Data System (ADS)

    Singh, Dharmaveer; Jain, Sanjay K.; Gupta, R. D.

    2015-06-01

    Ensembles of two Global Climate Models (GCMs), CGCM3 and HadCM3, are used to project future maximum temperature ( T Max), minimum temperature ( T Min) and precipitation in a part of Sutlej River Basin, northwestern Himalayan region, India. Large scale atmospheric variables of CGCM3 and HadCM3 under different emission scenarios and the National Centre for Environmental Prediction/National Centre for Atmospheric Research reanalysis datasets are downscaled using Statistical Downscaling Model (SDSM). Variability and changes in T Max, T Min and precipitation under scenarios A1B and A2 of CGCM3 model and A2 and B2 of HadCM3 model are presented for future periods: 2020s, 2050s and 2080s. The study reveals rise in annual average T Max, T Min and precipitation under scenarios A1B and A2 for CGCM3 model as well as under A2 and B2 scenarios for HadCM3 model in 2020s, 2050s and 2080s. Increase in mean monthly T Min is also observed for all months of the year under all scenarios of both the models. This is followed by decrease in T Max during June, July August and September. However, the model projects rise in precipitation in months of July, August and September under A1B and A2 scenarios of CGCM3 model and A2 and B2 of HadCM3 model for future periods.

  7. Preliminary Crater Retention Ages for an Expanded Inventory of Large Lunar Basins

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    2012-01-01

    Based on LOLA topography and a new crustal thickness model, the number of candidate lunar basins greater than 300 km in diameter is at least a factor 2 larger than the traditional number based on photogeology alone, and may be as high as 95. Preliminary N(50) crater retention ages for this population of candidate basins shows two distinct peaks. Frey [1] suggested, based on Clementine-era topography (ULCN2005) and a crustal thickness model based on Lunar Prospector data [2], that there could be as many as 98 lunar basins greater than 300 km diameter. Many of the weaker cases have not stood up to recent testing [3,4,5] using LOLA data and a newer crustal thickness model based on Kaguya gravity data and LOLA topography data [6]. As described in companion abstracts [4,5], we have deleted from the earlier inventory 1 more named feature (Sikorsky- Rittenhouse; LOLA data show that its diameter is actually less than 300 km), 11 Quasi-Circular Depressions (QCDs) identified in the ULCN topography, and 11 Circular Thin Areas (CTAs) found in the earlier crustal thickness model [2]. We did this by repeating the scoring exercise originally done in [1] but with the new data [4,5]. Topographic Expression (TE) and Crustal Thickness Expression (CTE) scores were determined for each candidate on a scale of 0 to 5 (5 being a strong, circular signature, 0 for those with no discernible circular topographic or crustal thickness signature). These scores are added together to produce a Summary Score which has a range of 0 to 10. We eliminated all candidates with a Summary Score less than 3, as well as other cases where, for example, the TE went to zero because what looked like a single large circular QCD in the lower resolution ULCN data was in fact a cluster of smaller deep impacts readily apparent in the newer higher resolution LOLA data. This process reduced the original inventory from 98 to 75 candidates.

  8. Restoring the Mississippi River Basin from the Catchment to the Coast Defines Science and Policy Issues of Ecosystem Services Associated with Alluvial and Coastal Deltaic Floodplains: Soil Conservation, Nutrient Reduction, Carbon Sequestration, and Flood Control

    NASA Astrophysics Data System (ADS)

    Twilley, R.

    2014-12-01

    Large river systems are major economic engines that provide national economic wealth in transporting commerce and providing extensive agriculture production, and their coastal deltas are sites of significant ports, energy resources and fisheries. These coupled natural and social systems from the catchment to the coast depend on how national policies manage the river basins that they depend. The fundamental principle of the Mississippi River Basin, as in all basins, is to capitalize on the ability of fertile soil that moves from erosional regions of a large watershed, through downstream regions of the catchment where sediment transport and storage builds extensive floodplains, to the coastal region of deposition where deltas capture sediment and nutrients before exported to the oceans. The fate of soil, and the ability of that soil to do work, supports the goods and services along its path from the catchment to the coast in all large river basin and delta systems. Sediment is the commodity of all large river basin systems that together with the seasonal pulse of floods across the interior of continents provide access to the sea forming the assets that civilization and economic engines have tapped to build national and global wealth. Coastal landscapes represent some of the most altered ecosystems worldwide and often integrate the effects of processes over their entire catchment, requiring systemic solutions to achieve restoration goals from alluvial floodplains upstream to coastal deltaic floodplains downstream. The urgent need for wetland rehabilitation at landscape scales has been initiated through major floodplain reclamation and hydrologic diversions to reconnect the river with wetland processes. But the constraints of sediment delivery and nutrient enrichment represent some critical conflicts in earth surface processes that limit the ability to design 'self sustaining' public work projects; particularly with the challenges of accelerated sea level rise. Only through rethinking how we manage the Mississippi River not only to provide for navigation and flood control, but also as the critical source of sediments to stabilize degrading wetlands, will restoration be realized in a 100-year project cycle.

  9. A preliminary assessment of the spatial sources of contemporary suspended sediment in the Ohio River basin, United States, using water quality data from the NASQAN programme in a source tracing procedure

    USGS Publications Warehouse

    Zhang, Y.-S.; Collins, A.L.; Horowitz, A.J.

    2012-01-01

    Reliable information on catchment scale suspended sediment sources is required to inform the design of management strategies for helping abate the numerous environmental issues associated with enhanced sediment mobilization and off-site loadings. Since sediment fingerprinting techniques avoid many of the logistical constraints associated with using more traditional indirect measurement methods at catchment scale, such approaches have been increasingly reported in the international literature and typically use data sets collected specifically for sediment source apportionment purposes. There remains scope for investigating the potential for using geochemical data sets assembled by routine monitoring programmes to fingerprint sediment provenance. In the United States, routine water quality samples are collected as part of the US Geological Survey's revised National Stream Quality Accounting Network programme. Accordingly, the geochemistry data generated from these samples over a 10-year period (1996-2006) were used as the basis for a fingerprinting exercise to assess the key tributary sub-catchment spatial sources of contemporary suspended sediment transported by the Ohio River. Uncertainty associated with the spatial source estimates was quantified using a Monte Carlo approach in conjunction with mass balance modelling. Relative frequency weighted means were used as an alternative way of summarizing the spatial source contributions, thereby avoiding the need to use confidence limits. The results should be interpreted in the context of the routine, but infrequent nature, of the suspended sediment samples used to assemble geochemistry as a basis for the sourcing exercise. Nonetheless, the study demonstrates how routine monitoring samples can be used to provide some preliminary information on sediment provenance in large drainage basins. ?? 2011 John Wiley & Sons, Ltd.

  10. Large-scale single incised valley from a small catchment basin on the western Adriatic margin (central Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Maselli, Vittorio; Trincardi, Fabio

    2013-01-01

    The Manfredonia Incised Valley (MIV) is a huge erosional feature buried below the Apulian shelf, on the western side of the Adriatic margin. The incision extends more than 60 km eastward, from the Tavoliere Plain to the outer shelf, not reaching the shelf edge. High-resolution chirp sonar profiles allow reconstruction of the morphology of the incision and its correlation at regional scale. The MIV records a single episode of incision, induced by the last glacial-interglacial sea level fall that forced the rivers draining the Tavoliere Plain to advance basinward, reaching their maximum extent at the peak of the Last Glacial Maximum. The valley was filled during a relatively short interval of about 10,000 yr during the Late Pleistocene-Holocene sea level rise and almost leveled-off at the time of maximum marine ingression, possibly recording the short-term climatic fluctuations that occurred. The accommodation space generated by the lowstand incision was exploited during the following interval of sea level rise by very high rates of sediment supply that allowed the preservation of up to 45 m of valley fill. High-resolution chirp sonar profiles highlight stratal geometries that are consistent with a typical transgressive valley fill of an estuary environment, including bay-head deltas, central basin and distal barrier-island deposits, organized in a backstepping configuration. The highest complexity of the valley fill is reached in the shallowest and most proximal area, where a kilometric prograding wedge formed during a period dominated by riverine input, possibly connected to high precipitation rates. Based on the depth of the valley margins during this interval, the fill was likely isochronous with the formation of sapropel S1 in the Mediterranean region and may have recorded significant fluctuations within the hydrological cycle.

  11. The effects of soil properties on the turbidity of catchment soils from the Yongdam dam basin in Korea.

    PubMed

    Hur, Jin; Jung, Myung Chae

    2009-06-01

    Environmental concerns have been raised that suspended solids in turbid water adversely affect human health, and that their removal increases in the cost of water treatment. The Yongdam dam reservoir, located in the southwestern region of Korea, is severely affected by inflowing turbid water after storms. In this study, soil samples were collected from 37 sites in the Yongdam upstream basin to investigate mineralogical and environmental factors associated with the turbidity potential of soils in water environments. Turbidity potential was estimated by measuring the turbidity of soil-suspension solutions after settling for 24 h. The mineralogy of the soils was dominated by four minerals-quartz, microcline, albite, and muscovite-with lesser amounts of hornblende, chlorite, kaolinite, illite, and mixed layer illite. The quartz content was the most variable of the soil mineralogy among the collected samples. Principal-components analysis (PCA) was used to examine relationships between turbidity potential and other soil properties. The variables considered in the PCA included turbidity potential, quartz content, albite content, mean size of soil particles, clay content, clay mineral content, zeta potential, conductivity, and pH of the soil-suspension solution. The first two components of the PCA explained 52% of the overall variation of the selected variables. The first component was possibly explained by physical properties such as the size of the soil particles; the second was correlated with chemical properties of the soils, for example dissolution and extent of weathering. Closer examination of the PCA results revealed that the quartz content of the soils was negatively correlated with their turbidity potential. A linear correlation (r = 0.63) was obtained between measured turbidity potential and that predicted using multiple regression analysis based on the content of clay-sized particles, clay minerals, and quartz, and the conductivity of the soil-suspension solution. PMID:18473181

  12. Preliminary digital model of the Arikaree aquifer in the Sweetwater River basin, central Wyoming

    USGS Publications Warehouse

    Borchert, W.B.

    1977-01-01

    In central Wyoming, Potentially large supplies of ground water are available in the Sweetwater River basin from the Arikaree aquifer, which consists of the upper part of the White River, the Arikaree, and the Ogallala Formations. A preliminary digital model was developed for the Arikaree aquifer using a small amount of poorly distributed data, an estimated distribution of recharge, and a conceptual model of the Arikaree aquifer flow system. Calibration of the model was based on reproduction of the potentiometric surface and the base flow of the Sweetwater River in November 1975. Calculated steady-state hydraulic heads were within 50 feet of the observed heads in about 98 percent of the nodes. The calculated leakage from the Arikaree aquifer to he Sweetwater River in the western area was within about 12 percent of the leadage determined by gain and loss studies. In order to develop a comprehensive digital model that would respond to hydraulic stress in nearly the same manner as the actual aquifer flow system, measured responses of the aquifer to stress are needed. Also needed are additional data on aquifer characteristics, recharge to the aquifer, and stream-aquifer relationships. (Woodard-USGS)

  13. Preliminary report on coal pile, coal pile runoff basins, and ash basins at the Savannah River Site: effects on groundwater

    SciTech Connect

    Palmer, E.

    1997-04-28

    Coal storage piles, their associated coal pile runoff basins and ash basins could potentially have adverse environmental impacts, especially on groundwater. This report presents and summarizes SRS groundwater and soil data that have been compiled. Also, a result of research conducted on the subject topics, discussions from noted experts in the field are cited. Recommendations are made for additional monitor wells to be installed and site assessments to be conducted.

  14. Preliminary study on the radiological and physicochemical quality of the Umgeni Water catchments and drinking water sources in KwaZulu-Natal, South Africa.

    PubMed

    Manickum, T; John, W; Terry, S; Hodgson, K

    2014-11-01

    Raw and potable water sample sources, from the Umgeni Water catchment areas (rivers, dams, boreholes) in central KwaZulu-Natal (South Africa), were screened for Uranium concentration and alpha and beta radioactivity. Test methods used were gas flow proportional counting for alpha-beta radioactivity, and kinetic phosphorescence analysis (KPA), for Uranium. The uranium levels (median = 0.525 μg/L, range = <0.050-5.010) were well below the international World Health Organization (WHO) (2011) guideline for drinking-water quality (≤15 μg/L). The corresponding alpha and beta radioactivity was ≤0.5 Bq/L (median = 0.084, Interquartile Range (IR) = 0.038, range = 0.018-0.094), and ≤1.0 Bq/L (median = 0.114, IR = 0.096, range = 0.024-0.734), respectively, in compliance with the international WHO limits. For uranium radionuclide, the average dose level, at uranium level of ±0.525 μg/L, was 0.06 μSv/a, which complies with the WHO reference dose level for drinking water (<0.1 mSv/a). There was a distinct trend of cluster of relatively higher Uranium levels of some sources that were found to be associated with the geology/geography and groundwater sources. Overall, the radiological water quality classification, with respect to WHO, is "Blue" - ideal; additional physicochemical analyses indicated good water quality. The analytical test methods employed were found to be suitable for preliminary screening for potential radioactive "hot spots". The observed Uranium levels, and the alpha/beta radioactivity, indicate contribution largely from Naturally Occurring Radioactive Material (NORM), with no significant health risk to humans, or to the environment. PMID:25151527

  15. Preliminary Measurements Of N2O Partial Pressures In Rivers of Amazon Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Oliveira, C. B.; Rasera, M. F.; Krusche, A. V.; Victoria, R. L.; Richey, J. E.; Cunha, H. B.; Gomes, B. M.

    2006-12-01

    The concentrations of nitrous oxide (N2O), an important component of the greenhouse effect and with a long residence time in the atmosphere, have significantly increased in this century. The reasons for this atmospheric increase in N2O are still partially unexplained. This uncertainty is worse in relation to aquatic environments. Here we report on preliminary measurements of N2O partial pressures in rivers of the Amazon basin. The study areas are in the state of Rondonia (rivers Ji Parana, Urupa, Comemoracao and Pimenta Bueno) and Amazonas (rivers Solimoes and Negro). The rivers were sampled from October 2005 to April 2006, using with immersion pumps, lowered in the middle of the channel to 60% of total depth. Water was pumped directly into a 1 l plastic bottle, which was overflown three times before closing. Using syringes, 60 ml of N2 were injected into the bottle, simultaenously to the withdrawn of 60 ml of sample. N2O was extracted into these 60 ml of N2 by shaking vigorously for 2 minutes. With the same syringes, the gas was taken from the bottles and injected into sealed evacuated 25 ml vials. Atmospheric samples were taken from one meter above the water column and stored the same way. N2O partial pressures were determined on a Shimadzu GC-14 Green House Gas Analyzer. All rivers showed little variations in N2O partial pressures. Average values in the rivers of Rondonia were around 0.41 0.07 ? atm (n=46), whereas the Solimoes and Negro rivers, in the state of Amazonas, showed values around 0.43 0.08 ? atm (n=131). Atmospheric averages were approximately 0.34 0.04 ? atm (n=58) and 0.32 0.03 ? atm (n=134) in the states of Rondonia and Amazonas, respectively. This means that, although these waters are supersatured in CO2, making evasive fluxes of this gas an important component of the C cycle in this basin, the same does not occur in the N cycle. Small differences in partial pressures of N2O between water and air will result in small fluxes of this gas to the atmosphere from the middle of the river channels. However, at the river margins and riparian zones, significantly different redox conditions may occur, which should be further investigated to fully understand the role of N2O fluxes in these riverine systems.

  16. Terrasar-X Insar Processing in Northern Bohemian Coal Basin Using Corner Reflectors (preliminary Results)

    NASA Astrophysics Data System (ADS)

    Hlav?ov, I.; Halounov, L.; Svobodov, K.

    2012-07-01

    The area of Northern Bohemian coal basin is rich in brown coal. Part of it is undermined, but large areas were mined using open-pit mines. There are numerous reclaimed waste dumps here, with a horse racetrack, roads and in some cases also houses. However, on most of the waste dumps, there are forests, meadows and fields. Above the coal basin, there are the Ore mountains which are suspected to be sliding down to the open mines below them. We installed 11 corner reflectors in the area and monitor them using the TerraSAR-X satellite. One of the reflectors is situated in the area of radar layover, therefore it cannot be processed. We present preliminary results of monitoring the remaining corner reflectors, with the use of 7 TerraSAR-X scenes acquired between June and December 2011. We process whole scene crops, as well as the artificial reflector information alone. Our scene set contains interferometric pairs with perpendicular baselines reaching from 0 to 150 m. Such a configuration allows us to distinguish deformations from DEM errors, which are usual when the SRTM (Shuttle Radar Topography Mission) DEM (X-band) is used for Stripmap data. Unfortunately, most of the area of interest is decorrelated due to vegetation that covers both the Ore mountains and the reclaimed waste dumps. We had to enlarge the scene crop in order to be able to distinguish deformations from the atmospheric delay. We are still not certain about the stability of some regions. For the installed artificial reflectors, the expected deformations are in the order of mm/year. Generally, deformations in the area of interest may reach up to about 5 cm/year for the Erv?nice corridor (a road and railway built on a waste dump). When processing artificial corner reflector information alone, we check triangular sums and perform the processing for all possible point combinations - and that allows us to correct for some unwrapping errors. However, the problem is highly ambiguous.

  17. Source rock potential and oil source correlation, Permian (Leonardian) strata, central Spraberry Trend, Midland basin, Texas - preliminary study

    SciTech Connect

    Guevara, E.H.; Mukhopadhyay, P.K.

    1987-05-01

    Wolfcampian-Leonardian sediments of the Midland basin comprise cyclic sequences of basinal terrigenous and carbonate mudstones overlain by terrigenous submarine-fan deposits. They have not undergone significant uplift, faulting, or water movement. Fractured sandstone and siltstone reservoirs of the Leonardian Spraberry Formation (lower and upper parts), having porosities of as much as 18% but generally less than 10% and permeabilities of less than 1 md, contain most of the 11 billion bbl of oil in the Spraberry/Dean play. About 700 ft (213 m) of basin-plain shales and carbonates, interbedded with basinal turbidite and fan-fringe sequences, separate lower and upper Spraberry reservoirs. Preliminary geochemical data (total organic carbon, petrography, pyrolysis, and liquid and gas chromatography) from the central Spraberry trend indicate occurrence of (1) mature potential oil-source rocks in the Spraberry Formation and at the base of overlying shales (basal Clear Fork) and (2) admixtures of terrestrial and marine organic matter, reflecting sediment transport to the basin center. Influence of terrestrial organic matter is greater in lower Spraberry shales (forming type III kerogen) and less important in the basal Clear Fork, which contains algal, sapropelic IIA kerogen having less hydrogen than do equivalent shallow marine source rocks. N-alkane distribution and biomarker ratios are similar in upper Spraberry oils and rock extracts. However, distribution and ratios in lower Spraberry oils differ from distribution and ratios in upper Spraberry oils and lower and upper Spraberry extracts.

  18. Multi-basin Hydrological Modeling at a Pan-European Scale Using a Combination of Catchment Classification and Regional Parameter Estimation

    NASA Astrophysics Data System (ADS)

    Hirpa, Y. H.; Kuentz, A.; Pechlivanidis, I.; Andersson, J.; Arheimer, B.

    2014-12-01

    Numerical hydrological models are essential tools for the retrieval of water information in many societal sectors. Although such models are usually applied at a catchment scale, there is an increasing need to model large spatial domains to be able to manage resources in a coordinated manner. However, modeling a large spatial domain brings with it a number of challenges. One of the issues that needs to be addressed is estimation of the model parameters under a situation where the physical and climate characteristics of the catchments making up the model domain are highly variable. A semi-distributed continuous hydrological model HYPE is applied to model daily stream flows over the entire pan-European region. The model includes simplified components to simulate human impacts, such as irrigation, reservoir regulation, and water abstraction. The entire region was subdivided into more than 35,000 subcatchments and a catchment classification scheme was implemented to group catchments based on similarity of their physiographic and climate characteristics. A range of catchment physiographic and climate attributes were used and principal component analysis was employed to reduce the dimensionality. These attributes were iteratively selected so that catchments of the same group have one or more of their hydrological signatures similar. The model parameters were estimated using a regionalization approach. Soil and landuse parameters were fixed based on soil and landuse classes respectively. Lake and irrigation parameters were estimated separately. Model parameters that are defined at a catchment scale were estimated for each group as functions of the catchment physical and climate characteristics. Simultaneous calibration was performed on a number of catchments to optimize the overall model performance and the functional relationships between the parameters and the catchment properties. ERA-interim reanalysis forcings were used as climate drivers and MODIS products were used to constrain the evapotranspiration parameters. Around 3,000 gauging stations were used to calibrate and validate the regionalization scheme. The regionalized parameters were evaluated by testing the performance on catchments that were not used in the derivation of the relationship and good results were obtained.

  19. Establishing Catchment Sediment Budgets

    NASA Astrophysics Data System (ADS)

    Walling, D. E.; Collins, A. L.

    2005-12-01

    The sediment budget concept, first introduced more than 40 years ago, is of fundamental importance to an understanding of the interaction between sediment mobilization, delivery, storage and yield within a catchment, and such understanding is a key requirement for designing effective sediment control and management strategies. However, despite its importance as a concept, from both a scientific and management perspective, there have to date been few successful attempts to establish detailed sediment budgets for individual catchments. Arguably, therefore, the sediment budget concept has yet to be fully exploited as a practical or operational tool within a management context. Recent advances in monitoring sediment loads, establishing sediment sources, documenting sediment mobilisation and storage on the slopes of a catchment and quantifying storage on river floodplains, in river channels and in other sediment sinks have, however, greatly advanced the potential for establishing reliable sediment budgets for small and intermediate sized catchments. In particular, the use of environmental or fallout radionuclides to trace sediment mobilization and transfer within a drainage basin has provided important new opportunities for obtaining spatially distributed and temporally integrated data on sediment mobilization, delivery and storage. Several examples of the application of these and related techniques to the establishment of sediment budgets for small and intermediate sized agricultural catchments in both the UK and overseas (e.g. Africa) will be presented. Despite such advances, significant problems still remain. These include the need to reconcile the different levels of temporal resolution associated with different techniques, and the inability to effect a rigorous budget closure in most investigations. The need for further work in developing techniques for establishing sediment budgets and in facilitating the application of the sediment budget concept as an operational tool will be reviewed.

  20. Tool for defining catchment similarity matrix

    NASA Astrophysics Data System (ADS)

    Singh, Shailesh Kumar; McMillan, Hilary; Brdossy, Andrs; Fateh, Chebana

    2014-05-01

    It is important to classify catchments for many reasons, for example, for prediction in ungauged basins, model parameterization and watershed development. There have been many studies on catchment classification, but no silver bullet exists for choosing the most relevant measure of catchment similarity. The aim of this study is to explore a new measure of similarity among catchments, using a data depth function. We used a similarity measure called "Depth-Depth plot" (DD-plot) which measures similarity in the catchment flow dynamics in multiple dimension. The area under the convex hull of DD-plot can be used as similarity matrix to any clustering technique. In this study we used Affinity propagation (AP) clustering algorithm for grouping the similar catchments. Catchment classifications based on flow and physical characteristics were compared. We evaluate whether the similarity based on depth-depth plots provides a better basis for transferring parameter sets of a hydrological model between catchments. We used a case study of 21 catchments located in the Bay of Plenty region in the North Island of New Zealand. The catchments have a wide range of topographic properties, response behaviours and geological features. The TopNet hydrological model was calibrated for all the catchments and the transferability of model parameters among the similar catchments was tested by transferring the parameters from within the cluster group and outside the group. The results of parameter transferred with in group based on Nash-Sutcliffe coefficient are promising. Results also show that clustering based on our proposed depth-depth measure, catchment characteristics, flow, and flow indices are different. The catchment classification of this study can be used to improve regional flood forecasting capabilities.

  1. Human impact variability on soil erosion during the Holocene based on valley floor sediments study in a Parisian basin fluvial catchment (France): crossing sedimentological, archaeological and palynological proxies

    NASA Astrophysics Data System (ADS)

    Morin, E.; Cyprien, A. L.; Gay-Ovejero, I.; Hinschberger, F.; Joly, C.; Macaire, J. J.; Poirier, N.; Visset, L.; Zadora-Rio, E.

    2009-04-01

    This work is part of the French CNRS ECLIPSE program Impact anthropique sur l'rosion des sols et la sdimentation dans les zones humides associes durant l'Holocne . It aims to reconstitute the evolution of human impact on soil erosion at various periods via the study of Holocene sedimentary archives. In this framework the Choisille catchment (288 km; elevation: 50 - 200 m), tributary of the River Loire near Tours (France), has been the subject of an interdisciplinary study (sedimentology, geophysics, archaeology, palynology). 3 areas are investigated: a downstream stretch, a silicated sub-catchment area and a carbonated sub-catchment area. In the downstream stretch, located near ancient populated areas, drillings were performed along cross sections through valley floor alluviums. They show that a more or less organic clayey silty sedimentation started at the beginning of the Holocene. The sedimentation rates strongly increased at the beginning of the Subbatlantic (Bronze Age), simultaneously with the anthropogenic pressure advent (on set of agriculture), as shown by archaeological and palynological evidences (agricultural settlements, massive loggings on slopes, stockbreeding on valley-floor grasslands). In the silicated sub-catchment area, located upstream, drillings have shown that clayey silty sedimentation began at the end of the Roman Period, continued during the Early Middle Ages and increased during the High Middle Ages. Spatial archaeological prospecting has revealed a faint anthropogenic presence at the Roman Period, then a decline of population until the High Middle Ages, characterised by an agricultural revival. Palynological analyses have shown that, in this area, grasslands were dominant since the Early Middle Ages, with an increase in cereal cultures at the beginning of the High Middle Ages. In the carbonated sub-catchment area, drillings have shown that the more or less organic clayey silty sedimentation has begun during the Bronze Age. Sedimentation rates have increased during the Modern era and the Contemporary history. The high fine sediment storage appeared and evolved differently, depending on the considered period and catchment valley area, due to variation of soil erosion. The difference between a fine, early and regularly increasing sedimentation in the downstream site and the later, intense and non-univocal sedimentation in the sub-catchments doesn't seem to be strictly resulting from natural factors. This idea and the palaeoenvironnemental dataset show that the fine sedimentation basically results from an anthropogenic impact, notably in the sub-catchments. Therefore soil exploitation by humans seems to be the main sedimentary production factor. This work mainly shows that anthropogenic impact (age of appearance, intensity) highly varies spatially, even into a little catchment. This variability would be led by the agricultural potential of the considered catchment valley area.

  2. Changes in alluvial architecture associated with Eocene hyperthermals: Preliminary results from the Bighorn Basin Coring Project

    NASA Astrophysics Data System (ADS)

    Acks, R.; Kraus, M. J.

    2012-12-01

    The Paleocene-Eocene Thermal Maximum (PETM) was followed by two lesser hyperthermal events: ETM2 and H2 both at ~53.7 Ma. The carbon isotope excursion for ETM2 was approximately half that of the PETM and the H2 excursion even smaller, indicating lower increases in temperature than during the PETM. The paleohydrologic responses to these events are less well understood than the response to PETM warming. Although the ETM2 and H2 events are better known from marine than continental strata, both events have been identified from outcrops of the alluvial Willwood Formation from the Deer Creek and Gilmore Hill areas of the Bighorn Basin, Wyoming (Abels et al., 2012). Here, we analyze two cores drilled from stratigraphically equivalent Willwood strata from Gilmore Hill. The cores provide an opportunity to examine the impact of these events on the architecture of fluvial strata. Willwood strata are composed largely of channel sandstones, heterolithic deposits generated by channel avulsion, and paleosols that formed on overbank deposits. The paleosols provide qualitative and quantitative information on changes in soil moisture and precipitation through this interval. The cores also show a distinct change in the stacking of paleosols The core is subdivided into three parts: (1) the lowest ~third has thinner, more densely spaced paleosols, (2) the middle has thicker paleosols that are more widely spaced, and (3) the upper third has thicker and more common channel sandstones interspersed with avulsion deposits and fewer red paleosols; this corresponds to the hyperthermal interval. In particular, a ~20 m thick sandstone complex caps the section and appears to truncate part of the hyperthermal interval. Although vertical variations in alluvial architecture can reflect tectonic or climatic change, the correspondence of the sandstone-rich part of the cores with the hyperthermals suggests climate was the major control on their formation. Thick purple paleosols associated with the hyperthermals at Deer Creek suggest wetter conditions, and our preliminary interpretation is that a change to wetter conditions caused increased discharge and deposition of coarser (sandy) sediment. The thick sandstone complex at Gilmore Hill is underlain by paleosols with abundant calcrete nodules, which indicate drier soil conditions prior to deposition of the sandstone, and the change from drier to wetter conditions probably also caused increased sediment yield.

  3. Neogene evolution of the Slovenj Gradec Basin, Northern Slovenia (preliminary results)

    NASA Astrophysics Data System (ADS)

    Trajanova, M.

    2012-04-01

    The Slovenj Gradec basin is situated along the west side of the Labot fault, adjacent to the Pohorje Mountains massif in northern Slovenia. This Neogene basin is tectonically bounded toward the older Paleozoic and Mesozoic formations. The most pronounced are the Labot fault to the east-northeast and the Periadriatic dextral shear fault zone to the south. Miocene sedimentary rocks of the wider Slovenj Gradec area were not considered as a part of Pannonian basin. More recent investigations, comprising radiometric dating, paleomagnetism and structural parameters (Mrton et al. 2006, Trajanova et al. 2008, Fodor et al. 2008), indicate that sediments of the wider Slovenj Gradec area correspond to the Miocene Pannonian basin formations. Calcareous nannoplankton assemblages found in the borehole MD-1 (?ori?, Trajanova & Lapanje, 2011) support marine environment of the deposition and correlate well with the findings in the Styrian and Mura-Zala basins (Jelen et al. 2008). Structural elements of the basin show three main evolutionary phases. Its initial stage is most probably influenced by the east-west extension connected to development of the Labot fault. It was accompanied with marginal normal faulting. This was probably lower Miocene (Ottnangian to Karpatian) D1 syntransgressional phase with synchronous rapid infilling of coarse material from the southern, western and northwestern basin's margins. Oblique north-easterly directed D2 compressive phase affected the south and south-eastern parts of the basin, while northwest-southeast extensional regime dominated in the area adjacent to the Labot fault. The western and southern margins of the basin were uplifted and erosion took place. Simultaneously, the connection to the Pannonian basin was cut off by the left rotating eastern parts of the Austroalpine units (Pohorje and Kozjak Mountains) (Mrton et al. 2008) and tilting of Pohorje along the Labot fault. As deduced from the cooling history of the Pohorje batholith, where the strongest tectonic activity took place at around 16,5 Ma and terminated in Badenian at around 15 Ma (Trajanova et al. 2008), this could be the time of the D2 deformations. Smaller collapse basin formed near the Labot fault, south of Slovenj Gradec. After detachment, the collapse basin was syntectonically rapidly filling up by Pliocene-Quaternary stream and alluvial fan sediments. The third deformational phase D3 is characterized by N-S compression, which reactivated most of the normal faults at the Slovenj Gradec basin margins in a reverse sense. At the same time, Pliocene infill of the collapse basin was slightly folded. This phase formed the final morphology of the area and is probably still active.

  4. Preliminary potential-field constraints on the geometry of the San Fernando basin, Southern California

    USGS Publications Warehouse

    Langenheim, V.E.; Griscom, Andrew; Jachens, R.C.; Hildenbrand, T.G.

    2000-01-01

    Gravity and magnetic data provide new insights on the structural underpinnings of the San Fernando Basin region, which may be important to ground motion models. Gravity data indicate that a deep basin (>5 km) underlies the northern part of the San Fernando Valley; this deep basin is required to explain the lowest gravity values over the Mission Hills thrust fault. Gravity modeling, constrained by well data and density information, shows that the basin may reach a thickness of 8 km, coinciding with the upper termination of the 1994 Northridge earthquake mainshock rupture. The basin is deeper than previous estimates by 2 to 4 km; this estimate is the result of high densities for the gravels of the Pliocene-Pleisocene Saugus Formation. The geometry of the southern margin of the deep basin is not well-constrained by the gravity data, but may dip to the south. Recently acquired seismic data along the LARSE (Los Angeles Regional Seismic Experiment) II profile may provide constraints to determine the location and attitude of the basin edge. Gravity and aeromagnetic models across the eastern margin of the San Fernando Valley indicate that the Verdugo fault may dip to the southwest along its southern extent and therefore have a normal fault geometry whereas it clearly has a thrust fault geometry along its northern strand.

  5. Microbial water pollution: a screening tool for initial catchment-scale assessment and source apportionment.

    PubMed

    Kay, D; Anthony, S; Crowther, J; Chambers, B J; Nicholson, F A; Chadwick, D; Stapleton, C M; Wyer, M D

    2010-11-01

    The European Union Water Framework Directive requires that Management Plans are developed for individual River Basin Districts. From the point of view of faecal indicator organisms (FIOs), there is a critical need for screening tools that can provide a rapid assessment of the likely FIO concentrations and fluxes within catchments under base- and high-flow conditions, and of the balance ('source apportionment') between agriculture- and sewage-derived sources. Accordingly, the present paper reports on: (1) the development of preliminary generic models, using water quality and land cover data from previous UK catchment studies for assessing FIO concentrations, fluxes and source apportionment within catchments during the summer bathing season; (2) the calibration of national land use data, against data previously used in the models; and (3) provisional FIO concentration and source-apportionment assessments for England and Wales. The models clearly highlighted the crucial importance of high-flow conditions for the flux of FIOs within catchments. At high flow, improved grassland (and associated livestock) was the key FIO source; FIO loadings derived from catchments with high proportions of improved grassland were shown to be as high as from urbanized catchments; and in many rural catchments, especially in NW and SW England and Wales, which are important areas of lowland livestock (especially dairy) farming, ? 40% of FIOs was assessed to be derived from agricultural sources. In contrast, under base-flow conditions, when there was little or no runoff from agricultural land, urban (i.e. sewerage-related) sources were assessed to dominate, and even in rural areas the majority of FIOs were attributed to urban sources. The results of the study demonstrate the potential of this type of approach, particularly in light of climate change and the likelihood of more high-flow events, in underpinning informed policy development and prioritization of investment. PMID:19717181

  6. Preliminary bathymetry of Shoup Basin and late Holocene changes of Shoup Glacier, Alaska

    USGS Publications Warehouse

    Post, Austin; Viens, R.J.

    2000-01-01

    Shoup Glacier is a retreating, tidewater-calving glacier in northeast Prince William Sound, Alaska. Historical records, vegetation distribution, and sediment depth in Shoup Bay indicate that the glacier reached a late Holocene maximum at the mouth of Shoup Bay prior to 1750. When first observed around 1900, the terminus was stable on a series of shallow, bedrock obstructions between Shoup Bay and Shoup Basin, 2 miles from the late Holocene maximum. Shoup Glacier receded into tidewater in 1957 and in the following 33 years retreated 1.3 miles to expose Shoup Basin, a deep (more than 350 feet) basin with virtually no sediment accumulation. Shoup Glacier is expected to stabilize at the head of Shoup Basin shortly after the year 2000 and will not readvance if present climatic conditions continue.

  7. Preliminary planktic and benthic foraminiferal biostratigraphy of cores from the Canada Basin, western Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Wan, E.; McGann, M. L.; Edwards, B. D.

    2011-12-01

    Arctic Ocean sediment cores are scarce, and typically contain sparse and poorly preserved microfaunal assemblages. Thus, any samples providing biostratigraphic age determinations are highly useful for understanding the tectonic and sedimentary history of the region. Fortunately, in 2010, interruptions in the acquisition of seismic data during a U.S.-Canadian expedition onboard the USCGC Healy provided the time to collect piston and gravity cores at five sites-of-opportunity in the Canada Basin. Preliminary data are now available for the lowest stratigraphic horizon of these cores. Piston core 1P-1 (5.71 m length; 71.32N, 144.00W; 2538 m water depth) was obtained on a piercement structure at the top of a mound and yielded only very rare recrystallized radiolarians and one planktic foraminifer, Neogloboquadrina pachyderma (Ehrenberg) C. This variant is a relatively small, sinistral-coiled form, with a quadrate test and relatively compressed axial periphery that often dominates cool water and polar assemblages. The estimated last occurrence of this taxon is ~1.88 Ma. Gravity core 1GB-1 (1.33 m length; 71.32N, 144.00W; 2530 m water depth) was obtained near 1P-1 and contains very rare planktic foraminifers (predominantly N. pachyderma C), as well as one N. pachyderma B, one benthic foraminifer, very rare radiolarians, and rare ostracods. Piston core 2P-1 (3.02 m length; 70.96N, 144.05W; 1157 m water depth), obtained from an outcrop near the edge of the Beaufort Shelf, contains a far more diverse microbiologic assemblage; centric diatoms are common, radiolarians are few, ostracods are rare, and benthic foraminifers are common to abundant. Piston core 3P-1 (4.94 m length; 81.58N, 134.48W; 3070 m water depth) was obtained on the crest of the 2009 seamount. The sample contains common to abundant microfossils possibly related to radiolarians (Phaeodarea?) and very rare planktic foraminifers: N. pachyderma C, N. pachyderma B, Neogloboquadrina humerosa praehumerosa (Natori), and Neogloboquadrina dutertrei (d'Orbigny). Piston core 4P-1 (3.37 m length; 75.58N, 140.09W; 3700 m water depth) was acquired on a distal submarine fan/channel. The sample contains very rare benthic foraminifers and rare planktic foraminifers. Though rare, the relative abundance and diversity of the latter is greatest in this sample compared to the other investigated samples. The planktic foraminifers include mostly N. pachyderma B, N. pachyderma pachyderma (right coiling), and N. cf. N humerosa praehumerosa, very few N. pachyderma C, rare Globigerina bulloides d'Orbigny, and Globigerinita glutinata (Egger). The presence of N. humerosa praehumerosa and the first appearance of right coiling N. pachyderma show this may be an early Pleistocene warming interval. Piston core 5P-1 (4.96 m length; 76.54N, 128.63W; 2081 m water depth) was obtained near WP37. Very rare, moderately to well-preserved, often infilled planktic foraminifers (N. pachyderma C) were recovered as well as one benthic foraminifer. Except for core 4P-1, the lowest stratigraphic horizon of each of these cores is indicative of an early Pleistocene (~1.88 Ma) estimated age.

  8. Modelling runoff from the Chamonix catchment in the French Alps: Preliminary results and assessment of the uncertainty related to glacial retreat.

    NASA Astrophysics Data System (ADS)

    Douglas, James; Huss, Matthias; Swift, Darrel; Jones, Julie

    2014-05-01

    Climate changes are likely to cause significant modifications to the future runoff regimes of alpine catchments, therefore, modelling this behaviour is advantageous. However, accurately determining future glacier behaviour is complex and requires significant input data and computing power. As such, recent studies have used novel techniques in an attempt to predict glacier behaviour. Here, the Glacier Evolution and Runoff Model (GERM; Huss et al., 2008) is calibrated for the Chamonix catchment in the French Alps. An extensive validation procedure is conducted to compare modelled mass balance, discharge and volume change with relevant measured data. Initial results show that while the model is capable of accurately predicting runoff and glacier changes for a short time, longer timescales show more uncertainty. GERM is then used to predict runoff changes until 2100 incorporating the uncertainty calculated from the validation procedure.

  9. A high-resolution geophysical investigation of sediment distribution controlled by catchment size and tides in a multi-basin turbid outwash fjord: Simpson Bay, Prince William Sound, Alaska

    NASA Astrophysics Data System (ADS)

    Noll, Christian J.; Dellapenna, Timothy M.; Gilkinson, Andrea; Davis, Randall W.

    2009-02-01

    Surficial sediment distribution within Simpson Bay is a function of antecedent bedrock and recently deposited glacial geology, as well as active physical processes both within Simpson Bay and Prince William Sound (PWS). Simpson Bay is a turbid, outwash fjord located in northeastern PWS, Alaska. Freshwater from heavy precipitation, and the melting of high alpine glaciers enter the bay through bay head rivers and small shoreline creeks. The catchment has a high watershed/basin surface area ratio (˜8:1), and easily erodible bedrock that contribute to high sediment loads. The system can be divided into three discrete basins, each with specific morphologic and circulatory characters. Side scan sonar, swath bathymetry, and seismic profiles reveal that bathymetric highs are areas of outcropping glacial surfaces. High backscatter coupled with surface grab samples reveal these surfaces to be composed of coarse sediment and bedrock outcrops. Bathymetric lows are areas of low backscatter, and grab samples reveal these areas to be ponded deposits of organic-rich estuarine muds. The data provide evidence of terminal morainal bank systems, and glacial grounding line deposits at the mouth of the bay and rocky outcrops were identified as subsurface extensions of aerial rocky promontories. Radioisotope analyses of short cores reveal that the bay has an average accumulation rate of approx. 0.5 cm year-1, but that this varies in function of the watershed/basin surface area ratios of the different basins. The interaction of tidal currents and sediment source drives sediment distribution in Simpson Bay. Hydrographic data reveal high spatial variability in surface and bottom currents throughout the bay. Subsurface currents are tide dominated, but generally weak (5-20 cm s-1), while faster currents are found along shorelines, outcrops, and bathymetric highs. Bathymetric data reveal steep slopes with little to no modern sediment throughout the bay, suggesting lack of deposition due to tidal currents.

  10. Preliminary gravity inversion model of basins east of Yucca Flat, Nevada Test Site, Nevada.

    SciTech Connect

    Geoffrey A. Phelps; Carter W. Roberts, and Barry C. Moring

    2006-03-17

    The Yucca Flat eastern extension study area, a 14 kilometer by 45 kilometer region contiguous to Yucca Flat on the west and Frenchman Flat on the south, is being studied to expand the boundary of the Yucca Flat hydrogeologic model. The isostatic residual gravity anomaly was inverted to create a model of the depth of the geologic basins within the study area. Such basins typically are floored by dense pre-Tertiary basement rocks and filled with less-dense Tertiary volcanic and sedimentary rocks and Quaternary alluvium, a necessary condition for the use of gravity modeling to predict the depth to the pre-Tertiary basement rocks within the basins. Three models were created: a preferred model to represent the best estimate of depth to pre-Tertiary basement rocks in the study area, and two end-member models to demonstrate the possible range of solutions. The preferred model predicts shallow basins, generally less than 1,000m depth, throughout the study area, with only Emigrant Valley reaching a depth of 1,100m. Plutonium valley and West Fork Scarp Canyon have maximum depths of 800m and 1,000m, respectively. The end-member models indicate that the uncertainty in the preferred model is less than 200m for most of the study area.

  11. Preliminary interpretation of industry two-dimensional seismic data from Susitna Basin, south-central Alaska

    USGS Publications Warehouse

    Lewis, Kristen A.; Potter, Christopher J.; Shah, Anjana K.; Stanley, Richard G.; Haeussler, Peter J.; Saltus, Richard W.

    2015-01-01

    The eastern seismic lines show evidence of numerous short-wavelength antiforms that appear to correspond to a series of northeast-trending lineations observed in aeromagnetic data, which have been interpreted as being due to folding of Paleogene volcanic strata. The eastern side of the basin is also cut by a number of reverse faults and thrust faults, the majority of which strike north-south. The western side of the Susitna Basin is cut by a series of regional reverse faults and is characterized by synformal structures in two fault blocks between the Kahiltna River and Skwentna faults. These synforms are progressively deeper to the west in the footwalls of the east-vergent Skwentna and northeast-vergent Beluga Mountain reverse faults. Although the seismic data are limited to the south, we interpret a potential regional south-southeast-directed reverse fault striking east-northeast on the east side of the basin that may cross the entire southern portion of the basin.

  12. A preliminary report of the geohydrology of the Mississippi Salt-Dome Basin

    USGS Publications Warehouse

    Spiers, C.A.; Gandl, L.A.

    1980-01-01

    The U.S. Department of Energy is investigating the suitability of salt domes in the Mississippi salt-dome basin as repositories for storing radioactive wastes. The Department of Energy has requested that the U.S. Geological Survey describe the groundwater hydrology of the Mississippi salt-dome basin, giving special attention to direction and rate of movement of water. In this first part of a continuing investigation the data obtained from one year of extensive literature search and data compilation are summarized. The regional groundwater hydrology in the salt-dome basin is defined with respect to (1) groundwater flow, (2) facies changes, (3) geological structure, (4) recharge and discharge, (5) freshwater-saltwater relations, and (6) identification of localities where additional data are needed. From the 50 piercement-type salt domes in the Mississippi salt-dome basin three domes (Richton, Cypress Creek, and Lampton) were selected for more intensive study. To further evaluate the geohydrology of Richton, Lampton, and Cypress Creek domes as possible sites for storage of radioactive waste, an intensive geohydrologic study based on a comprehensive test drilling program near the domes is planned. (USGS)

  13. Potential impacts of climate change on tropospheric ozone in California: a preliminary episodic modeling assessment of the Los Angeles basin and the Sacramento valley

    SciTech Connect

    Taha, Haider

    2001-01-01

    In this preliminary and relatively short modeling effort, an initial assessment is made for the potential air quality implications of climate change in California. The focus is mainly on the effects of changes in temperature and related meteorological and emission factors on ozone formation. Photochemical modeling is performed for two areas in the state: the Los Angeles Basin and the Sacramento Valley.

  14. Preliminary Geologic/spectral Analysis of LANDSAT-4 Thematic Mapper Data, Wind River/bighorn Basin Area, Wyoming

    NASA Technical Reports Server (NTRS)

    Lang, H. R.; Conel, J. E.; Paylor, E. D.

    1984-01-01

    A LIDQA evaluation for geologic applications of a LANDSAT TM scene covering the Wind River/Bighorn Basin area, Wyoming, is examined. This involves a quantitative assessment of data quality including spatial and spectral characteristics. Analysis is concentrated on the 6 visible, near infrared, and short wavelength infrared bands. Preliminary analysis demonstrates that: (1) principal component images derived from the correlation matrix provide the most useful geologic information. To extract surface spectral reflectance, the TM radiance data must be calibrated. Scatterplots demonstrate that TM data can be calibrated and sensor response is essentially linear. Low instrumental offset and gain settings result in spectral data that do not utilize the full dynamic range of the TM system.

  15. Analysis of suspended sediment transport in a mesoscale catchment in northern Mongolia

    NASA Astrophysics Data System (ADS)

    Theuring, Philipp; Rode, Michael

    2010-05-01

    The input of fine sediments has an important impact on the ecological status of rivers. In case of the investigated 15.000km2 Kharaa catchment in Mongolia it is assumed to be the main source for pollutants and nutrients. The identification of the sediment sources and the quantification of sediment transport are therefore important for river management measures, especially in semi-arid Mongolia where massive climate and land use changes are expected. Since data scarcity is a central problem in the investigated area a monitoring scheme has been developed, providing continuous data on discharge, turbidity and temperature at selected sites. In this study two different models are tested to describe sediment transport on a mesoscale. The semi distributed, conceptual hydrological and nutrient transport model HYPE is used to model the runoff in the catchment. The model has been development based on the HBV-model that allows the use of coupled sub basins. Secondly a regional catchment scale sediment budget model (SedNet) is employed to calculate the sediment budget. This model uses a DEM, land use- and soil maps and climate data and is taking into account also hill slope, gully- and riverbank erosion. Sediment source fingerprinting is used to identify and localize the most important sediment sources in the catchment. Geochemical tracer techniques for spatial source identification, using major elements (e.g. Si, Al, Mg, Fe, Na, K, P) and trace elements (e.g. Ba, Pb, Sr, Zn) are applied. Samples from the river junctions of the outlet of each sub basin into the main tributary were taken and the fine sediment fraction (<10?m) has been analysed. The contribution of each sub basin of the suspended sediment in the main tributary has been assessed with the help of a mixing model. Further sampling has been conducted on a selection of topsoil eroding surface reference sites and on stream banks, in order to gain information about the importance and proportions of surface-, stream bank and gully erosion in the catchment. These samples are used for an isotope fingerprinting using the atmospheric fallout radionuclides 137Cs, 210Pb and 7Be. Preliminary results suggest that only a small part of the catchment contributes considerably to total sediment load. The coupling of the catchment model with an in stream River Water Quality model in the future will lead to a better understanding of the influencing factors on the aquatic ecosystems in the Kharaa River and allow the analysis of land use and climate change scenarios.

  16. Magnetostratigraphy of Mesozoic shallow-water carbonates: Preliminary results from the Middle Jurassic of the Paris basin

    SciTech Connect

    Aissaoui, D.M.; Kirschvink, J.L. )

    1991-03-01

    The use of sedimentary paleomagnetism has enhanced greatly our understanding of the timing of deposition and diagenesis of Cenozoic platform and reefal carbonates. Its application to similar but older deposits will have direct implications for economic exploration and development. The authors report here preliminary paleomagnetic results from the Middle Jurassic limestones of the Paris basin (France). The samples consist mainly of bioclastic and oolitic limestones deposited in ancient counterpart of the shallow-water environments of the Bahama platform. The Jurassic samples are stable to progressive, incremental demagnetization and exhibit magnetization patterns identical to Cenozoic rocks from the Bahama platform or Mururoa Atoll. The natural remanent magnetization of these limestones is weak and comprised between 7.7 x 10{sup {minus}9} to 1.8 x 10{sup {minus}8} AM{sup 2}/kg. Magnetic components of both normal and reversed polarity are observed. Paired isothermal remanent magnetization (IRM) and alternating field demagnetization experiments show that most of the remanence is lost between 20 and 45 mT, which is typical of single-domain biogenic magnetite or maghemite. The ratio of IRM at H{sub RG} to the saturation IRM ranges from 35 to 42% indicating a moderate to low interparticle interaction. This is confirmed by the anhysteretic remanent magnetization as compared with intact, freeze-dried cells of magnetotactic bacteria and chiton teeth. Magnetic minerals extracted from the Jurassic samples are examined to further confirm the occurrence of SD magnetite within the Middle Jurassic limestones of the Paris basin. The preliminary results suggest that the strata should be good for the paleomagnetic investigation of Mesozoic shallow-water carbonates.

  17. Tectonic Evolution of the Ohrid Basin (Macedonia/Albania): preliminary results for a future ICDP deep drilling site

    NASA Astrophysics Data System (ADS)

    Hoffmann, N.; Reicherter, K.; Fernández-Steeger, T.; Arndt, M.

    2009-04-01

    In the frame of the planned ICDP deep drilling site within the Lake Ohrid (Macedonia/Albania, SCOPSCO initiative), we are focusing on the tectonic framework of the site. The Ohrid basin is an important N-S trending graben structure in Macedonia/Albania and located within the Afro-European Convergence Zone a region with dispersed active seismicity. In contrast to the compressive coastal part of Albania the central and eastern part are presently subject to extension. Earthquake focal mechanisms showed active N-S normal faulting with horst and graben structures, in a basin and range like environment. Several pronounced scarps testify to an active, seismogenic landscape as revealed also from DEM data. Paleozoic metamorphic and magmatic rocks form the country rock of the Western Macedonian Zone around Lake Ohrid. Triassic carbonates and clastics are widely exposed to the southeast and northwest of the lake. These rocks bear the imprints of several deformation phases that affected the basin system since the Late Cretaceous to present. However, until today the different steps in the tectonic evolution of the graben is not clear. Therefore, we started to investigate the (neo)tectonic evolution of Lake Ohrid with a field campaign focusing on the collection of structural data, like paleostress data (fault-slip data) and mapping of folds, joints and fractures. We studied a total of 24 sites along the steep flanks and the mountains surrounding Lake Ohrid, with suitable fault-slip data for stress inversion. At each location we measured a representative number of fault planes concerning the spatial orientation of fault plane (dip direction, dip) and striae (azimuth, plunge) and additional the sense of slip (reverse, normal, dextral or sinistral). After separation and classification of the data the preliminary results already show a tendency of three major deformation phases affecting the surroundings of Ohrid Basin: NW-SE, NE-SW horizontal contraction and later an almost vertical uplift with E-W extension. The multiple inverse method of Yamaji (2000) was applied on datasets with a polyphase stress history and to investigate the spatial and temporal variations of paleostresses in the Ohrid Basin. The applied methods led us to the following preliminary results: - Three main phases of deformation can be assumed NW-SE shortening, NE-SW shortening and a present-day extension - Morphological lineations, which are directed NNE-SSW, NW-SE, and E-W fit in the assumed pattern of faults - Earthquake focal solutions and data of the world stress map data point to SW-NE directed extension and normal faulting acting presently - The origin of the lake formation is unclear, possibly an older tectonic transtensional phase or reactivation of inherited faults led to a pull-apart like opening of the basin, followed by E-W directed extension. Reference: Yamaji, A., 2000. The multiple inverse method: a new technique to separate stresses from heterogeneous fault-slip data. J. Struct. Geol. 22, 441-452

  18. A Preliminary Investigation of the Yallalie Basin: A Buried 15 KM Diameter Structure of Possible Impact Origin in the Perth Basin, Western Australia

    NASA Astrophysics Data System (ADS)

    Dentith, M. C.; Bevan, A. W. R.; McInerney, K. B.

    1992-07-01

    In late 1990, Ampol Exploration drew the attention of the senior author to an enigmatic structure located in Mesozoic rocks in the Dandaragan Trough of the Perth Basin about 200 km north of Perth, Western Australia. The basin-like Yallalie structure, centred on coordinates ca. 30 degrees 28'S, 115 degrees 47'E, is subcircular in plan view and about 15 km in diameter. Recognizing structures beneath the basin likely to contain oil, Ampol carried out an intensive geophysical survey of the area, and subsequently drilled a well (Yallalie 1). The well proved to be dry and exploration ceased. Generously, Ampol and their partners have made available the results of their exploration for a research project into the nature of the structure. Geology and regional setting: The exposed geology of the Yallalie basin area comprises discontinuous sequences of sedimentary rocks (sandstones, siltstones and shales) of Middle Jurassic to Late Cretaceous age that are capped by laterite and locally covered by thin (<50 m) Cenozoic eolian, colluvial and alluvial deposits (Cockbain, 1990). Modern, high-resolution, seismic reflection profiles across the Yallalie structure show a basin-shaped area of chaotic reflections that extend down to a depth of approximately 2 km below the surface. The structure has sharp boundaries with surrounding faulted, but otherwise relatively undisturbed rocks. At the base of the structure there is a central uplifted area approximately 3-4 km across similar to those described from complex impact structures (Dence et al., 1977). A preliminary survey of the area has shown that exposed rocks of the Yarragadee Formation (Middle Jurassic to Lower Cretaceous) and the succeeding Warnbro (Lower Cretaceous) and Coolyena (Late Cretaceous) Groups dip gently and their deposition appears to have postdated the underlying structure of intensely disturbed rocks. Although the structure is "draped" by a thin (a few hundred metres) veneer of late Jurassic to Cretaceous rocks it has some surface expression. A broad depression approximately 120 m deep is centered on Yallalie Well and is bounded to the west and north by a marked "rim." The area is characterized by a radial pattern of drainage that flows into the depression and which is gradually exhuming the buried structure. A southerly flowing stream drains the depression and has breached the "rim" to the south. Evidence for impact at Yallalie: Quartz grains taken from the core at a depth of 430-460 m in the Yallalie 1 well show widesprad development of prismatic cleavage fractures and irregular, slightly curved planes formed by brittle fracture. Quartz grains from a depth of 150-180 m in the well are essentially undeformed (McInerney, 1991). However, multiple sets of closely spaced planar features in quartz, characteristic of highly shocked rocks, have yet to be observed in core material from the Yallalie structure. Nevertheless, the morphology of the Yallalie structure determined from geophysical data suggests strongly that it is of impact origin. Work is continuing on the core material to search for diagnostic shock-metamorhic effects, and to constrain the age of the structure. References Cockbain A. E. (1990) In Geology and Mineral Resources of Western Australia, Western Australia Geological Survey, Memoir 3, pp. 514-516. Dence M. R., Grieve R. A. F., and Robertson P. B. (1977) In Impact and Explosion Cratering (eds. D. J. Roddy, R. O. Pepin, and R. B. Merrill), Pergamon Press, pp. 247-275. McInerney K. B. (1991) Honors Thesis (unpublished), University of Western Australia.

  19. Origins of streamflow in a crystalline basement catchment in a sub-humid Sudanian zone: The Donga basin (Benin, West Africa): Inter-annual variability of water budget

    NASA Astrophysics Data System (ADS)

    Sguis, L.; Kamagat, B.; Favreau, G.; Descloitres, M.; Seidel, J.-L.; Galle, S.; Peugeot, C.; Gosset, M.; Le Barb, L.; Malinur, F.; Van Exter, S.; Arjounin, M.; Boubkraoui, S.; Wubda, M.

    2011-05-01

    SummaryDuring the last quarter of the 20th century, West Africa underwent a particularly intense and generalized drought. During this period, the biggest drops in streamflow were observed in the Sudanian zone rather than in the Sahelian zone, but the reasons are still poorly understood. In 2000, a meso-scale hydrological observatory was set up in the sub-humid Sudanian zone of the Upper Oum Valley (Benin). Three embedded catchments of 12-586 km 2 located on a crystalline bedrock were intensively instrumented to document the different terms of the water budget and to identify the main streamflow generating processes and base-flow mechanisms at different scales. Geophysical, hydrological and geochemical data were collected throughout the catchments from 2002 to 2006. Crossing these data helped define their hydrological functioning. The region has seasonal streamflow, and the permanent groundwater in the weathered mantle does not drain to rivers, instead, seasonal perched groundwaters are the major contributor to annual streamflow. The perched groundwaters are mainly located in seasonally waterlogged sandy layers in the headwater bottom-lands called bas-fonds in French-speaking West Africa of 1st order streams. During the period 2003-2006, regolith groundwater recharge ranged between 10% and 15% of the annual rainfall depth. Depletion of permanent groundwater during the dry season is probably explained by local evapotranspiration which was seen not to be limited to gallery forests. During the 4-year study period, a reduction of 20% in annual rainfall led to a 50% reduction in streamflow. This reduction was observed in the two components of the flow: direct runoff and drainage of perched groundwater. Thanks to the comprehensive dataset obtained, the results obtained for the Donga experimental catchment are now being extrapolated to the whole upper Oum valley, which can be considered as representative of sub-humid Sudanian rivers flowing on a crystalline basement, for example, the upper courses of several major West African rivers (Senegal, Niger, Bani, and Volta).

  20. New Seismic Reflection Profiling Across the Northern Newark Basin USA: Data Acquisition and Preliminary Results

    NASA Astrophysics Data System (ADS)

    Tymchak, M.; Collins, D.; Brown, C.; Conrad, J.; Papadeas, P.; Coueslan, M. L.; Tamulonis, K.; Goldberg, D.; Olsen, P. E.

    2011-12-01

    Deep saline formations in basins underlying major population centers represent opportunities for carbon (CO2) sequestration, but intensive surface development in such settings can hinder field operations to acquire geologic and geophysical data critical to effective characterization. Seismic-reflection is a tool that can be used to characterize basins and their potential capacity for carbon storage. The northern part of the Triassic-Jurassic Newark Rift Basin represents a potential storage opportunity for carbon as a result of its proximity to large-scale CO2 emitters; however, a lack of deep geologic and seismic data from this area has precluded evaluation of this basin to date. As part of the Department of Energy's (DOE) National Energy Technology Labs (NETL) Carbon Sequestration programs portion of the American Recovery and Reinvestment Act (ARRA)- and NYSERDA-funded TriCarb Consortium for Carbon Sequestration basin characterization project, two new seismic-reflection profiles were acquired in the northern portion of the Newark Basin in Rockland County, NY and Bergen County NJ. This densely developed region, proximal to New York City, presents a variety of challenges for seismic surveys, including route selection and access, community acceptance, high traffic volumes and associated data noise, in addition to regulatory requirements and private property limitations. In spite of these challenges, two high-resolution, perpendicular lines were successfully surveyed in late March and early April, 2011; one dip line extending 21 km (13 mi) across most of the basin (east-west), and a shorter strike line extending 8 km (5 mi, north-south). The survey lines intersected near the location of a planned 8,000 ft stratigraphic borehole to be drilled by the TriCarb consortium. Three vibroseis trucks comprised the source array. Source points were spaced at 36.5 m (120-ft) intervals and geophone accelerometers collected data at a 3.05 m (10 ft) intervals. Seismic-reflection data processing included three main objectives: 1) attenuate high levels of noise related to the high volume traffic, 2) constrain the depth and thickness of the diabase sill at the planned borehole site and 3) optimize the image of potential reservoirs relative to the diabase sill. The high volume traffic noise was successfully removed from the data using several attenuation algorithms. Refraction statics were selected individually to improve reflector coherency over the automated solution and single sensor data were used throughout to maximize frequency bandwidth and reduce smearing related to the offset 2D geometry. In general, these techniques revealed a well-defined basin image that exhibits structural characteristics of an eroded half graben. The diabase sill and potential reservoirs appear to be well-imaged near the planned borehole site. The successful completion of this survey and final product demonstrate that geophysical data acquisition can be achieved in highly developed regions that have carbon storage potential.

  1. Preliminary study of solar ponds for salinity control in the Colorado River Basin. Technical report

    SciTech Connect

    Boegli, W.J.; Dahl, M.M.; Remmers, H.E.

    1982-12-01

    In this study, the Bureau of Reclamation investigates the technical and economic benefits of using solar salt-gradient ponds in the Colorado River Basin to provide salinity control and to produce project power and freshwater. It was assumed that the saline water needed for pond construction would be transported to one of two dry lakebeds in the Basin(Danby Dry Lake in southern California or Sevier Dry Lake in western Utah) as part of a salinity control/coal transport project. The ponds would be used to generate electric power that could be integrated with the Bureau's power grid or used in combination with thermal energy from the ponds to power commercially available desalination systems to produce freshwater. Economic benefits were compiled for two methods of concentrating the necessary brine for the ponds--one representing stage construction using collected brine only and the other using salt at the site to produce the concentrated brine.

  2. Preliminary gravity inversion model of Frenchman Flat Basin, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Phelps, Geoffrey A.; Graham, Scott E.

    2002-01-01

    The depth of the basin beneath Frenchman Flat is estimated using a gravity inversion method. Gamma-gamma density logs from two wells in Frenchman Flat constrained the density profiles used to create the gravity inversion model. Three initial models were considered using data from one well, then a final model is proposed based on new information from the second well. The preferred model indicates that a northeast-trending oval-shaped basin underlies Frenchman Flat at least 2,100 m deep, with a maximum depth of 2,400 m at its northeast end. No major horst and graben structures are predicted. Sensitivity analysis of the model indicates that each parameter contributes the same magnitude change to the model, up to 30 meters change in depth for a 1% change in density, but some parameters affect a broader area of the basin. The horizontal resolution of the model was determined by examining the spacing between data stations, and was set to 500 square meters.

  3. Preliminary gravity inversion model of Frenchman Flat Basin, Nevada Test Site, Nevada

    SciTech Connect

    Phelps, G.A.; Graham, S.E.

    2002-10-01

    The depth of the basin beneath Frenchman Flat is estimated using a gravity inversion method. Gamma-gamma density logs from two wells in Frenchman Flat constrained the density profiles used to create the gravity inversion model. Three initial models were considered using data from one well, then a final model is proposed based on new information from the second well. The preferred model indicates that a northeast-trending oval-shaped basin underlies Frenchman Flat at least 2,100 m deep, with a maximum depth of 2,400 m at its northeast end. No major horst and graben structures are predicted. Sensitivity analysis of the model indicates that each parameter contributes the same magnitude change to the model, up to 30 meters change in depth for a 1% change in density, but some parameters affect a broader area of the basin. The horizontal resolution of the model was determined by examining the spacing between data stations, and was set to 500 square meters.

  4. Hydrological dynamics of a Mediterranean catchment in a global change context. (Romanyac catchment, Cap de Creus, Girona, Spain)

    NASA Astrophysics Data System (ADS)

    Latron, J.; Pardini, G.; Gispert, M.; Llorens, P.

    2009-04-01

    Mediterranean regions are characterized by unevenly distributed water resources, and consequently a more precise knowledge of the main hydrological processes and their variability and changes is crucial for a better management of water resources. However, the lack of hydrological information and data in most areas of the Mediterranean basin greatly difficult the analyses of changes in water resources at relevant scales. In this context, the Soil Science Unit GRCT48 from the University of Girona is conducting an integrated study of hydrological response, soil erosion and soil degradation processes in fragile Mediterranean areas undergoing changes in use and management. The study area is located in the Cap de Creus Peninsula (NE Spain), where land abandonment has been the outstanding characteristic over the last decades. The area is covered by terraced soils, most of them abandoned, and stands for a representative Mediterranean environment. Current land cover is a mosaic of areas with different shrubs according to wildfire occurrence. Residual patches of cork and pine trees are also present as well as small extensions of pastures. Finally some localized areas of vineyards and olive trees are still cultivated. The approach is based on the complementary use of plot and catchment scales to assess the effect of land cover and land use change on physical, chemical and biological parameters of soil quality and on rainfall-runoff-erosion relationships. Along the study period, observed rainfall-runoff response at the plot scale was highly variable among sites but also for a given environment, depending on antecedent wetness conditions and rainfall characteristics. Overall, surface runoff responses were low in all environments. Soil loss associated to rainfall-runoff events showed very large variations among sites, and also for a given site, between the different rainfall events. At the catchment scale, preliminary results obtained from the monitoring, of three catchments of different sizes (0.25 to 9.36 km2). showed that catchment scale runoff represented around 17% of the annual rainfall (507 mm) and that evapotranspiration was consequently the more relevant component of the water balance. Observed runoff happened in less than two months, whereas the stream remained totally dry during half of the year. Preliminary rainfall-runoff modelling results obtained at the event scale, showed that adequate simulation of the catchment response could be achieved with a relatively simple hydrological model.

  5. Methodological issues and preliminary results from a combined sediment fingerprinting and radioisotope dating approach to explore changes in sediment sources with land-use change in the Brantian Catchment, Borneo.

    NASA Astrophysics Data System (ADS)

    Walsh, Rory; Higton, Sam; Marshall, Jake; Bidin, Kawi; Blake, William; Nainar, Anand

    2015-04-01

    This paper reports some methodological issues and early results of a project investigating the erosional impacts of land use changes (multiple selective logging and progressive, partial conversion to oil palm) over the last 25-40 years in the 600km2 Brantian river catchment in Sabah, Borneo. A combined sediment fingerprinting and radioisotope dating approach is being applied to sediment cores taken in stream hierarchical fashion across the intermediate catchment scale. Changes in sediment sources and sedimentation rates over time can be captured by changes in the relative importance of geochemical elements with depth in downstream sediment cores, which in turn can be linked to parallel changes in upstream cores by the application of unmixing models and statistical techniques. Radioisotope analysis of the sediment cores allows these changes to be dated and sedimentation rates to be estimated. Work in the neighbouring Segama catchment had successfully demonstrated the potential of such an approach in a rainforest environment (Walsh et al. 2011). The paper first describes steps taken to address methodological issues. The approach relies on taking continuous sediment cores which have aggraded progressively over time and remain relatively undisturbed and uncontaminated. This issue has been tackled (1) through careful core sampling site selection with a focus on lateral bench sites and (2) deployment of techniques such as repeat-measurement erosion bridge transects to assess the contemporary nature of sedimentation to validate (or reject) candidate sites. The issue of sediment storage and uncertainties over lag times has been minimised by focussing on sets of above- and below-confluence sites in the intermediate zone of the catchment, thus minimising sediment transit times between upstream contributing and downstream destination core sites. This focus on the intermediate zone was also driven by difficulties in finding suitable core sites in the mountainous headwaters area due to the prevalence of steep, incised channels without even narrow floodplains. Preliminary results are reported from (1) a field visit to investigate potential sampling sites in July 2014 and (2) initial analysis of a sediment core at a promising lateral bench site. Marked down-profile geochemistry changes of the core indicate a history of phases of high deposition and lateral growth of the channel caused by mobilisation of sediment linked to logging and clearance upstream. Recent channel bed degradation suggests the system has been adjusting a decline in sediment supply with forest recovery since logging in 2005, but a renewed sedimentation phase heralded by > 10 cm deposition at the site in a flood in July 2014 appears to have started linked to partial forest clearance for oil palm. These preliminary results support the ability of a combined fingerprinting and dating approach to reflect the spatial history of land-use change in a catchment undergoing disturbance. Walsh R. P. D. , Bidin K., Blake W.H., Chappell N.A., Clarke M.A., Douglas I., Ghazali R., Sayer A.M., Suhaimi J., Tych W. & Annammala K.V. (2011) Long-term responses of rainforest erosional systems at different spatial scales to selective logging and climatic change. Philosophical Transactions of the Royal Society B, 366, 3340-3353.

  6. Nutrient removal using biosorption activated media: preliminary biogeochemical assessment of an innovative stormwater infiltration basin

    USGS Publications Warehouse

    O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Xuan, Zhemin; Harris, Willie G.

    2012-01-01

    Soil beneath a stormwater infiltration basin receiving runoff from a 22.7 ha predominantly residential watershed in central Florida, USA, was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.9:4.1 mixture (by volume) of tire crumb (to increase sorption capacity), silt and clay (to increase soil moisture retention), and sand (to promote sufficient infiltration), which was applied to develop a prototype stormwater infiltration basin utilizing nutrient reduction and flood control sub-basins. Comparison of nitrate/chloride (NO3-/Cl-) ratios for the shallow groundwater indicate that prior to using BAM, NO3- concentrations were substantially influenced by nitrification or variations in NO3- input. In contrast, for the prototype basin utilizing BAM, NO3-/Cl- ratios indicate minor nitrification and NO3- losses with the exception of one summer sample that indicated a 45% loss. Biogeochemical indicators (denitrifier activity derived from real-time polymerase chain reaction and variations in major ions, nutrients, dissolved and soil gases, and stable isotopes) suggest NO3- losses are primarily attributable to denitrification, whereas dissimilatory nitrate reduction to ammonium is a minor process. Denitrification was likely occurring intermittently in anoxic microsites in the unsaturated zone, which was enhanced by increased soil moisture within the BAM layer and resultant reductions in surface/subsurface oxygen exchange that produced conditions conducive to increased denitrifier activity. Concentrations of total dissolved phosphorus and orthophosphate (PO43-) were reduced by more than 70% in unsaturated zone soil water, with the largest decreases in the BAM layer where sorption was the most likely mechanism for removal. Post-BAM PO43-/Cl- ratios for shallow groundwater indicate predominantly minor increases and decreases in PO43- with the exception of one summer sample that indicated a 50% loss. Differences in nutrient variations between the unsaturated zone and shallow groundwater may be the result of the intensity and duration of nutrient removal processes and mixing ratios with water that had not undergone significant chemical changes. Observed nitrogen and phosphorus losses demonstrate the potential, as well as future research needs to improve performance, of the prototype stormwater infiltration basin using BAM for providing passive, economical, stormwater nutrient-treatment technology to support green infrastructure.

  7. Tectonic evolution and subsidence history of the Nenana Basin, Interior Alaska: Preliminary results from seismic-reflection, electric logs and gravity data

    NASA Astrophysics Data System (ADS)

    Dixit, N. C.; Hanks, C. L.; Tomsich, C. S.

    2012-12-01

    The Nenana basin is an elongated Tertiary structural half-graben located in Interior Alaska, between the Denali fault to the south and the Tintina fault to the north. Although the basin has been explored for oil, gas and coal episodically over the past 40 years, the timing and mechanisms that are responsible for its formation remain unclear. Our preliminary work offers new insights into the tectonic subsidence history and structural history of the basin. Seismic-reflection and gravity data indicate that the Tertiary sedimentary fill of the southern Nenana basin is up to 19,500 ft deep, resulting in a Complete Bouguer gravity anomaly with a low of -50 mgal. The southeast margin of the basin is formed by the Minto fault, a major, steeply dipping, east-northeast striking fault. The fault shows evidence of both significant sinistral strike-slip and down-to-the-west normal faulting, with metamorphic rocks of the Yukon-Tanana terrane exposed to the east and Quaternary deposits to the west. Secondary active normal faults in the basin are oriented west-northwest and east-northeast and indicate a probable ongoing sinistral transtension across the Minto fault zone. Our preliminary interpretation of these geometries suggest that the Nenana basin is superimposed on a crustal block rotating clockwise within a dextral shear zone bounded by the regional Denali and Tintina fault systems, which is probably the direct driver of present tectonic subsidence in the basin. Further details as to the subsidence history of the basin can be derived from the geometry, thickness and seismic character of the Tertiary basin fill. The basin experienced three phases of subsidence and two uplift events during this time, possibly due to regional tectonic events during the history of Interior Alaska. The most important tectonic control that may have resulted in periods of basin subsidence was probably Tertiary strike-slip faulting of the Denali and Tintina fault systems, and subsequent transtension across the Minto fault zone. Growth of the basin during the Tertiary widened the basin to the west. Other far-field driving mechanisms that may have controlled basin subsidence to lesser degrees include subduction of a spreading center along the former coast of southern Alaska (61 Ma- 50 Ma) and resulting oroclinal bending of western Alaska in response to the northwestward shift in plate convergence (60 Ma - 42 Ma). Burial history models further indicate that the basin experienced two different inversion events, possibly in response to increased northward compressive stresses. These compressive regimes may be due to Kula-Pacific plates reorganization (42 Ma - 23 Ma) and/or ongoing flab-slab subduction of Yakutat block beneath south-central Alaska (26 Ma to present day). Our preliminary study accounts for the structure of the southern Nenana basin primarily as the result of combination of Tertiary transtension, transpression and strike-slip faulting, and suggests that the present-day geometry of the basin resembles a pull-apart structure.

  8. Hydrologic responses of a tropical catchment in Thailand and two temperate/cold catchments in north America to global warming

    SciTech Connect

    Gan, T.Y.; Ahmad, Z.

    1997-12-31

    The hydrologic impact or sensitivities of three medium-sized catchments to global warming, one of tropical climate in Northern Thailand and two of temperate climate in the Sacramento and San Joaquin River basins of California, were investigated.

  9. Geology of the Ahuas area in the Mosquitia basin of Honduras: Preliminary report

    SciTech Connect

    Mills, R.A.; Barton, R.

    1996-10-01

    Following a 36-fold seismic survey that covered 460 km, two exploratory wells were drilled between July 1991 and August 1993 in the Ahuas area, on the Patuca tectonic belt, in the Mosquitia savannah in northeastern Honduras. The Embarcadero 1 well encountered only dense, barren, gray and red siliciclastics and some phyllite at total depth. The RaitiTara 1 well also drilled mostly barren, but less dense, red beds that included some Upper Cretaceous limestone conglomerate in the lower section. We did not find source or reservoir rocks in either well, nor did we find hydrocarbon shows. The absence of Lower Cretaceous limestone in both wells is significant because more than 1500 m of limestone are exposed 35-50 km southwest in the Colon Mountains. The lithology of the clastics in the Embarcadero well is similar to Middle and Upper Jurassic formations in central Honduras. The lithology of the softer red beds in the Raiti-Tara well suggests they are Tertiary fill in a pull-apart basin. The Mosquitia basin, including the Ahuas area, probably was on the seaward side of the Chortis block (once part of Mexico) and received only Jurassic sediments until it was elevated by arc magmatism in the Early Cretaceous. However, thick Lower Cretaceous platform carbonates were deposited some distance inland. Lateral forces in the early Late Cretaceous caused the outer edge of Chortis to break up, carrying the Colon carbonate block up to 50 km northwest by sinistral fault movement. Later, antithetic dextral displacement offset the various blocks and created pull-apart basins that filled with Tertiary sediments. In the early Paleocene, compression from a spreading center to the southeast ruptured the Jurassic rocks, creating a decollement and later thrusting. No complete petroleum system seems to exist along the axis of the uplifted Patuca tectonic belt largely because of the lack of organic-rich source rocks and the presence of complicated young structures.

  10. Preliminary study of the diversion of 283 m 3 s -1 (10,000 cfs) from Lake Superior to the Missouri River basin

    NASA Astrophysics Data System (ADS)

    Bulkley, J. W.; Wright, S. J.; Wright, D.

    1984-02-01

    Trans-basin diversion is an established practice in this country. The High Plains Study authorized by the U.S. Congress in 1976 examined large-scale intra-basin diversion to replenish the depleted groundwater resources of the Ogallala aquifer. A portion of this intra-basin diversion could come from the Missouri River basin. This study presents the preliminary engineering associated with a large-scale diversion of Lake Superior water out of the Great Lakes and into the Missouri River basin in order to replace intra-basin water diverted for recharge of the Ogallala aquifer. The magnitude of the diversion is 283 m 3 s -1 (10,000 cfs). The first cost of the conveyance structure is estimated at US 19.6 billion. The total length is estimated at 984 km and the total static lift including friction losses, static head, and pumping plant losses is 1130 m. It is estimated that eighteen pumping plants will be required to lift the water from Lake Superior and transport it to the Missouri Basin. This study estimated an energy requirement to move this water equivalent to the annual energy production from seven 1000-MW plants. Initial costs of these power plants is estimated at 7 billion.

  11. Effect of initial conditions of a catchment on seasonal streamflow prediction using ensemble streamflow prediction (ESP) technique for the Rangitata and Waitaki River basins on the South Island of New Zealand

    NASA Astrophysics Data System (ADS)

    Singh, Shailesh Kumar; Zammit, Christian; Hreinsson, Einar; Woods, Ross; Clark, Martyn; Hamlet, Alan

    2013-04-01

    Increased access to water is a key pillar of the New Zealand government plan for economic growths. Variable climatic conditions coupled with market drivers and increased demand on water resource result in critical decision made by water managers based on climate and streamflow forecast. Because many of these decisions have serious economic implications, accurate forecast of climate and streamflow are of paramount importance (eg irrigated agriculture and electricity generation). New Zealand currently does not have a centralized, comprehensive, and state-of-the-art system in place for providing operational seasonal to interannual streamflow forecasts to guide water resources management decisions. As a pilot effort, we implement and evaluate an experimental ensemble streamflow forecasting system for the Waitaki and Rangitata River basins on New Zealand's South Island using a hydrologic simulation model (TopNet) and the familiar ensemble streamflow prediction (ESP) paradigm for estimating forecast uncertainty. To provide a comprehensive database for evaluation of the forecasting system, first a set of retrospective model states simulated by the hydrologic model on the first day of each month were archived from 1972-2009. Then, using the hydrologic simulation model, each of these historical model states was paired with the retrospective temperature and precipitation time series from each historical water year to create a database of retrospective hindcasts. Using the resulting database, the relative importance of initial state variables (such as soil moisture and snowpack) as fundamental drivers of uncertainties in forecasts were evaluated for different seasons and lead times. The analysis indicate that the sensitivity of flow forecast to initial condition uncertainty is depend on the hydrological regime and season of forecast. However initial conditions do not have a large impact on seasonal flow uncertainties for snow dominated catchments. Further analysis indicates that this result is valid when the hindcast database is conditioned by ENSO classification. As a result hydrological forecasts based on ESP technique, where present initial conditions with histological forcing data are used may be plausible for New Zealand catchments.

  12. Preliminary study on avian fauna of the Krishna River basin Sangli District, Western Maharashtra, India.

    PubMed

    Kumbar, Suresh M; Ghadage, Abhijit B

    2014-11-01

    The present study on avifaunal diversity carried out for three years at the Krishna River Basin, Sangli District revealed a total of 126 species of birds belonging to 30 families, of which 91 species were resident, 16 migratory, 12 resident and local migratory and 7 species were resident and migratory. Among the migrant birds, Rosy Starling Sturnus roseus was dominant in the study area. Commonly recorded resident bird species were, Red vented bulbul, Jungle crow, House sparrow, Common myna, Brahminy myna, Rock pigeon, Spotted dove, Rose ringed parakeet, Indian robin, White-browed fantail-flycatcher and Small sunbird. Most of the families had one or two species, whereas Muscicapidae family alone had 16 species. Forty one species of waterfowls were recorded in this small landscape. Out of 126 bird species, 38 were insectivorous, 28 piscivorous, 25 omnivorous, 19 carnivorous, 9 granivorous, 5 frugivorous and 2 species were nectar sucker and insectivorous. These results suggest that richness of avifauna in the Krishna River Basin, Western Maharashtra might be due to large aquatic ground, varied vegetations and favourable environmental conditions. PMID:25522499

  13. Preliminary Results of Heat Flow Experiments during IODP Expedition 317 (Canterbury Basin, New Zealand)

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Lee, S.; Shipboard Scientific Party, E.; Expedition 317 Shipboard Scientific Party

    2010-12-01

    Heat flow was estimated from cores recovered from the Canterbury Basin located on the eastern margin of the South Island of New Zealand during Integrated Ocean Drilling Program Expedition 317. Thermal conductivity, measured on recovered cores using the TK04 system, ranges from 0.849 to 3.440 W/m/K. In general, the thermal conductivity values increase with depth and correlate positively and negatively with bulk density and porosity, respectively. However, these relationships are not evident in the topmost several hundred meters of the cores. This may be due to the abundance within that interval of high thermal conductivity materials such as quartz, which are thought to have been transported from onshore and deposited during periods of low sea level. At Site U1352, which drilled to 1927 mbsf below the Marshall Paraconformity, an abrupt increase in thermal conductivity was found in the depth interval 600-800 mbsf, coinciding with a lithological transition from marl to limestone together with related changes in porosity and shear strength. Attempts to measure formation temperature failed owing to the hardness of the sediments, except at Site U1352 where the thermal gradient was measured as 46.2 mK/m. The estimated heat flow of 57.8 mW/m^2 is comparable to other values from the region. We anticipate that accurate determination of the thermal history of the Canterbury Basin will provide an opportunity to elucidate the past sea level change and the tectonic evolution of New Zealand.

  14. Role of bacterial mats in oxygen-deficient marine basins and coastal upwelling regimes: Preliminary report

    NASA Astrophysics Data System (ADS)

    Williams, Loretta Ann; Reimers, Clare

    1983-05-01

    Bacterial mats play an important role in the sedimentation history of many marine biogenic regimes. Observations of the living mats suggest that in shallow waters they are dominated by photosynthetic cyanobacteria, while in deeper waters the mats are dominated by nonphotosynthetic sulfur-oxidizing bacteria. Fossilized remains of analogous mat structures from the Miocene Monterey Formation are commonly associated with oil-producing and phosphate-rich zones. Preliminary observations suggest that bacterial mats may be a source of the organic matter that in time is thermally altered to hydrocarbons.

  15. Co-evolution of volcanic catchments in Japan

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Troch, P. A.

    2015-09-01

    Present day landscapes have evolved over time through interactions between the prevailing climates and geological settings. Understanding the linkage between spatial patterns of landforms, soils, and vegetation in landscapes and their hydrological response is critical to make quantitative predictions in ungaged basins. Catchment co-evolution is a theoretical framework that seeks to formulate hypotheses about the mechanisms and conditions that determine the historical development of catchments and how such evolution affects their hydrological response. In this study, we selected 14 volcanic catchments of different ages (from 0.225 to 82.2 Ma) in Japan. We derived indices of landscape properties (drainage density) as well as hydrological response (annual water balance, baseflow index, and flow duration curves) and examined their relation with catchment age and climate (through the aridity index). We found significant correlation between drainage density and baseflow index with age, but not with climate. The age of the catchments was also significantly related to intra-annual flow variability. Younger catchments tend to have lower peak flows and higher low flows, while older catchments exhibit more flashy runoff. The decrease of baseflow with catchment age confirms previous studies that hypothesized that in volcanic landscapes the major flow pathways have changed over time, from deep groundwater flow to shallow subsurface flow. The drainage density of our catchments decreased with age, contrary to previous findings in similar volcanic catchments but of significant younger age than the ones explored here. In these younger catchments, an increase in drainage density with age was observed, and it was hypothesized that this was because of more landscape incision due to increasing near-surface lateral flow paths in more mature catchments. Our results suggests two hypotheses on the evolution of drainage density in matured catchments. One is that as catchments further evolve, hydrologically active channels retreat as less recharge leads to lower average aquifer levels and less baseflow; the other is that it does not significantly change after catchments reached maturity in terms of surface dissection.

  16. A new perspective on catchment storage gained from a nested catchment experiment in Luxembourg (Europe)

    NASA Astrophysics Data System (ADS)

    Pfister, Laurent; Klaus, Julian; Hissler, Christophe; François Iffly, Jean; Gourdol, Laurent; Martinez-Carreras, Nuria; McDonnell, Jeffrey J.

    2014-05-01

    Recent hydrological process research focussed on how much water a catchment can store and how these catchments store and release water. Storage can be a valuable metric for catchment description, inter-comparison, and classification. Further storage controls catchment mixing, non-linearities in rainfall-runoff transformation and eco-hydrological processes. Various methods exist to determine catchment storage (e.g. natural tracer, soil moisture and groundwater data, hydrological models). Today it remains unclear what parts of the catchment storage are measured with the different models. Here we present a new hydrometric approach to answer the question how much water a catchment can store. We tested our approach in a dense hydro-climatological monitoring network that encompasses 16 recording streamgauges and 21 pluviographs in the Alzette River basin in Luxembourg (Europe). Catchment scales are ranging from 0.47 to 285 km2 and they have clean- and mixed combinations of distinct geologies ranging from schists to marls, sandstone, dolomite and limestone. Previous investigations in the area of interest have shown that geology largely controls winter runoff coefficients. Here, we focus at how catchment geology is ultimately affecting catchment storage. We used the approach of Sayama et al. (2011) to compute catchment dynamic storage changes for each winter season over the period 2002-2012 (based on precipitation as input; discharge and evapotranspiration as output). We determined dynamic storage changes for each winter semester (October to March) in all 16 catchments over the period 2002-2012. At the beginning of each hydrological winter season, all catchments showed similar trends in storage change. A few weeks into the winter season, catchments with lowest permeability (e.g. marls) started to plateau. The highest storage values were reached several months later in the season in catchments dominated by permeable substrate (e.g. sandstone). For most catchments, we found strong correlations between baseflow prior to the recharge period (i.e. at initiation of the total storage calculations) and the seasonal maximum value of the total storage change calculations. In order to determine the maximum storage potential for each catchment, we fitted a trendline through the annual 'initial baseflow - maximum storage' populations. By extrapolating these trendlines to zero flow conditions, we obtained the maximum storage potential. Our results show that these maximum storage values clearly tend to be larger in catchments dominated by permeable substrate, compared to areas underlain by impermeable bedrock. In the latter, average filling ratios were found to be substantially higher (exceeding 80%) than in catchments dominated by permeable substrate (approximately 40%). These findings were confirmed by average seasonal winter runoff coefficients that are substantially higher in catchments dominated by impermeable bedrock (Pfister et al., in prep.). Our new approach allows a fast assessment of storage potential in catchments based on discharge, precipitation and evapotranspiration data. Pfister L. et al. 2014: Catchment storage, baseflow isotope signatures and basin geology: Is there a connection? In preparation. Sayama, T., McDonnell, J.J., Dhakal, A., Sullivan, K., 2011. How much water can a watershed store ? Hydrological Processes 25, 3899-3908.

  17. Magnetic Fabric of the Itarar Group, Paran Basin Brazil: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Raposo, M. B.; Bilardello, D.; Santos, P. R.

    2012-12-01

    The late Paleozoic Itarar Group and equivalent beds in the Paran Basin of Brazil extend into Paraguay, Argentina, and Uruguay. The Itarar Group contains the most extensive lithological record of Gondwana glaciation in the world. The succession has a maximum subsurface thickness of around 1400 m and extends over a total area greater than 1 million km2. The lower boundary of the Itarar Group is nonconformable with Precambrian to early Paleozoic crystalline basement and with Devonian strata of the Furnas and Ponta Grossa Formations, which together constitute the base of the Gondwana supersequence of the Paran Basin. This boundary encompasses a hiatus that is loosely estimated in 45 Ma. The upper contact with the overlying Rio Bonito Formation is described as conformable to partially erosional. We performed our study on 13 sites from sedimentary rocks (sandstones and siltites) from the Itarar beds in the Brazilian portion of the Paran Basin (mainly in So Paulo State). Magnetic fabrics were determined on oriented cylindrical specimens (2.54 cm x 2.2 cm) using the anisotropy of low-field magnetic susceptibility (AMS). Rock-magnetic analyses reveal that magnetite is the main magnetic mineral. In one of the sampled site, however, the ferromagnetic minerals are both magnetite and hematite. Regarding the eingenvector orientations, the sites usually gave good results. The analysis at the individual-site scale defines three AMS fabric types. The first type (7 sites) shows Kmin perpendicular to the bedding plane while Kmax and Kint are scattered within the bedding plane itself. This fabric is usually interpreted as primary (sedimentary-compactional), typical of undeformed sediments. The second type (5 sites) shows good clustering of the AMS principal axes with Kmin still sub-perpendicular to the bedding plane. The third type, pertaining to an intensely folded site previously interpreted as slumped, is characterized in geographic coordinates by well-clustered Kmax in the bedding plane, while Kmin and Kint are distributed along a NE-SW girdle with a sub-vertical, yet elongate Kmin distribution. In stratigraphic coordinates Kmax maintains the same NNW-SSE clustering, yet Kmin and Kint become scattered within the girdle. The second fabric type would be interpreted as combination of sedimentary-compactional and tectonic contributions if some strain markers or evidence for tectonic deformation had been found in the studied area. On the other hand, the tight Kmax grouping in this fabric type could be explained by the action of currents since they cause Kmax to be aligned sub-parallel to the paleocurrent direction.

  18. Mid-Neolithic Exploitation of Mollusks in the Guanzhong Basin of Northwestern China: Preliminary Results

    PubMed Central

    Li, Fengjiang; Wu, Naiqin; Lu, Houyuan; Zhang, Jianping; Wang, Weilin; Ma, Mingzhi; Zhang, Xiaohu; Yang, Xiaoyan

    2013-01-01

    Mollusk remains are abundant in archaeological sites in the Guanzhong Basin of Northwestern China, providing good opportunities for investigations into the use of mollusks by prehistoric humans. Here we report on freshwater gastropod and bivalve mollusks covering the time interval from about 5600 to 4500 cal. yrs BP from sites of Mid-Late Neolithic age. They are identified as Cipangopaludina chinensis and Unio douglasiae, both of which are currently food for humans. The shells are well preserved and have no signs of abrasion. They are all freshwater gastropods and bivalves found in pits without water-reworked deposits and have modern representatives which can be observed in rivers, reservoirs, and paddy fields in the studied region. Mollusk shells were frequently recovered in association with mammal bones, lithic artifacts, and pottery. These lines of evidence indicate that the mollusks are the remains of prehistoric meals. The mollusk shells were likely discarded into the pits by prehistoric humans after the flesh was eaten. However, these mollusk remains may not have been staple food since they are not found in large quantities. Mollusk shell tools and ornaments are also observed. Shell tools include shell knives, shell reaphooks and arrowheads, whereas shell ornaments are composed of pendants and loops. All the shell tools and ornaments are made of bivalve mollusks and do not occur in large numbers. The finding of these freshwater mollusk remains supports the view that the middle Holocene climate in the Guanzhong Basin may have been warm and moist, which was probably favorable to freshwater mollusks growing and developing in the region. PMID:23544050

  19. CHARIS - The Contribution to High Asian Runoff from Ice and Snow, Preliminary results from the Upper Indus Basin, Pakistan

    NASA Astrophysics Data System (ADS)

    Armstrong, R. L.; Barrett, A. P.; Brodzik, M.; Fetterer, F. M.; Hashmey, D.; Horodyskyj, U. N.; Khalsa, S.; Racoviteanu, A.; Raup, B. H.; Williams, M. W.; Wilson, A.

    2013-12-01

    The goal of the CHARIS project is to improve the understanding of the regional water resources of High Asia. In order to achieve this goal CHARIS is a cross-boundary exercise with University of Colorado scientists working directly with researchers at institutions in nine different nations where these ice and snow resources are located (Bhutan, Nepal, India, Pakistan, Afghanistan, Kazakhstan, Uzbekistan, Kyrgyzstan, Tajikistan). These countries contain the headwaters of the Brahmaputra, Ganges, Indus, Syr Darya and Amu Darya rivers. This collaboration includes both joint research and capacity building that includes augmented field programs and technical training. While it is generally accepted that a significant component of these water resources results from the melting of glacier ice and seasonal snow, the actual water volume available from these two individual sources remains uncertain. The amount, timing, and spatial patterns of snow and ice melt play key roles in providing water for downstream irrigation, hydropower generation, and general consumption. The fundamental objective of this collaborative study is to develop a thorough and systematic assessment of the separate contributions from seasonal snow melt and from glacier ice melt to the water resources originating across the region. To accomplish project objectives, a suite of satellite remote sensing, reanalysis and ground based data are applied as input to specific snow and ice melt models. Gridded maps of snow and glacier area/elevation are used as input to temperature-index melt models to estimate runoff from snow covered grid cells, based on cell area and melt depth. Glacier melt is estimated in the same way, once seasonal snow has disappeared from glacierized grid cells. The melt models are driven by daily mean temperature from reanalysis data. We are comparing the melt volume time series generated from temperature-index models with measured river discharge volumes and comparing the regional scale results with local sub-basin studies based on energy balance modeling approaches. We are also evaluating the accuracy of the melt model results using isotopic and geochemical tracers to identify and quantify the sources of water (ice melt, snow melt, rainfall and ground water) flowing into selected rivers representing the major hydro-climates of the study area. Preliminary results are presented for the Upper Indus Basin, and the Hunza sub-basin, for the period 2000-2012.

  20. Preliminary results of polarization signatures for glacial moraines in the Mono Basin, Eastern Sierra Nevada

    NASA Technical Reports Server (NTRS)

    Forster, Richard R.; Fox, Andrew N.; Isacks, Bryan

    1992-01-01

    The valleys of the Mono Basin contain several sets of lateral and terminal moraines representing multiple stages of glaciation. The semi-arid climate with slow weathering rates preserved sequences of nested younger moraines within older ones. There is a well established relative chronology and recently exposure dating provided a new set of numerical dates. The moraines span the late Wisconsin (11-25 ka) to the Illinoian (130-190 ka) glaciations. The Mono Basin area was used as a 'calibration site' to establish remote dating techniques for eventual transfer to the more inaccessible but geomorphically and climatically similar moraines of the South American Andes Mountains. Planned polarimetric synthetic aperture radar (SAR) imagery acquired by JPL AIRSAR (South American Campaign) and SIR-C (Andes super-site) are analyzed to establish chronologies of previously undated moraine sequences in a study of Pleistocene climatic change in the Southern Hemisphere. The dry climate and sparse vegetation is also favorable for correlation of ground surface roughness with radar polarization signature. The slow weathering processes acting over thousands of years reduce the size, frequency, and angularity of surface boulders while increasing soil development on the moraines. Field observations based on this hypothesis result in relative ages consistent with those inferred from nested position within the valley. Younger moraines, therefore, will appear rougher than the older smoother moraines at scales measurable at AIRSAR wavelengths. Previously documented effects of ground surface roughness on polarization signatures suggest that analysis of moraine polarization signatures can be useful for relative dating. The technique may be extended to predict numerical ages. The data set reported were acquired on 8 Sep. 1989 with the JPL Airborne SAR (AIRSAR) collecting polarimetric imagery at C- (5.6 cm), L- (24 cm), and P-band (68 cm) with a flight-line parallel to the strike of the mountains. Phase calibration was performed on the analyzed scene by setting the co-phase of a smooth lake to zero as described. Absolute amplitude calibration was not possible because corner reflectors were not deployed.

  1. Impact of Urbanization on Stormwater Runoff from a Small Urban Catchment: Gdańsk Małomiejska Basin Case Study

    NASA Astrophysics Data System (ADS)

    Olechnowicz, Borys; Weinerowska-Bords, Katarzyna

    2014-12-01

    This paper deals with the impact of different forms of urbanization on the basin outflow. The influence of changes in land cover/use, drainage system development, reservoirs, and alternative ways of stormwater management (green roofs, permeable pavements) on basin runoff was presented in the case of a small urban basin in Gdansk (Poland). Seven variants of area development (in the period of 2000-2012) - three historical and four hypothetical - were analyzed. In each case, runoff calculations for three rainfall scenarios were carried out by means of the Hydrologic Modeling System designed by Hydrologic Engineering Center of the U.S. Army Corps of Engineers (HEC-HMS). The Soil Conservation Service (SCS) Curve Number (CN) method was used for calculations of effective rainfall, the kinematic wave model for those of overland flow, and the Muskingum-Cunge model for those of channel routing. The calculations indicated that urban development had resulted in increased peak discharge and runoff volume and in decreased peak time. On the other hand, a significant reduction in peak values was observed for a relatively small decrease in the normal storage level (NSL) in reservoirs or when green roofs on commercial centers were present. The study confirmed a significant increase in runoff as a result of urbanization and a considerable runoff reduction by simple alternative ways of stormwater management.

  2. Channel erosion and sediment transport in Pheasant Branch basin near Middleton, Wisconsin; a preliminary report

    USGS Publications Warehouse

    Grant, R. Stephen; Goddard, Gerald

    1980-01-01

    The purpose of this 5-year study is to (1) evaluate the sediment transport, streamflow characteristics, and stream-channel morphology, (2) relate the above to land-use practices; and (3) evaluate the effect that changes in land-use practices will have on Pheasant Branch basin near Middleton, Wis. This report presents findings of sediment transport, streamflow characteristics, and stream-channel morphology from the first year of the study and documents historical erosion. The study is being conducted by the U.S. Geological Survey in cooperation with the city of Middleton and the Wisconsin Geological and Natural History Survey. Pheasant Branch, a tributary to Lake Mendota, drains 23.1 square miles of glacial drift. Channel erosion is severe within Middleton, requiring extensive use of erosion-control structures. Occasionally, channel dredging near the mouth and into Lake Mendota is required for boating. Comparison of stream-channel surveys of 1971 and 1977 shows the lowest part of the channel lowered 3 to 4 feet at some sites in the urban reach from U.S. Highway 12 downstream to Century Avenue. Downstream from Century Avenue, channel width increased from about 35 to 48 feet and channel cross-section area increased about 86 percent. A survey of Pheasant Branch in 1971 provided data for quantification of stream-channel changes since that time. Six erosion-control structures previously installed appear to have had some benefit in controlling head cutting in the channel. (USGS).

  3. Monitoring of wild fish health at selected sites in the Great Lakes Basin: methods and preliminary results

    USGS Publications Warehouse

    Blazer, Vicki; Mazik, Patricia M.; Iwanowicz, Luke R.; Braham, Ryan; Hahn, Cassidy; Walsh, Heather L.; Sperry, Adam

    2014-01-01

    During fall 2010 and spring 2011, a total of 119 brown bullhead (Ameiurus nebulosus), 136 white sucker (Catostomus commersoni), 73 smallmouth bass (Micropterus dolomieu), and 59 largemouth bass (M. salmoides) were collected from seven Great Lakes Basin Areas of Concern and one Reference Site. Comprehensive fish health assessments were conducted in order to document potential adverse affects from exposure to complex chemical mixtures. Fish were necropsied on site, blood samples obtained, pieces of liver, spleen, kidney, gill and any abnormalities placed in fixative for histopathology. Liver samples were saved for gene expression analysis and otoliths were removed for aging. A suite of fish health indicators was developed and implemented for site comparisons and to document seasonal effects and species differences in response to environmental conditions. Organism level (grossly visible lesions, condition factor), tissue level (microscopic pathology, organosomatic indices, micronuclei, and other nuclear abnormalities), plasma factors (reproductive steroid hormones, vitellogenin), and molecular (gene expression) indicators were included. This report describes the methods and preliminary results.

  4. Preliminary report on coal resources of the Wyodak-Anderson coal zone, Powder River Basin, Wyoming and Montana

    USGS Publications Warehouse

    Ellis, Margaret S.; Gunther, Gregory L.; Flores, Romeo M.; Ochs, Allen M.; Stricker, Gary D.; Roberts, Steven B.; Taber, Thomas T.; Bader, Lisa R.; Schuenemeyer, John H.

    1998-01-01

    The National Coal Resource Assessment (NCRA) project by the U.S. Geological Survey is designed to assess US coal with the greatest potential for development in the next 20 to 30 years. Coal in the Wyodak-Anderson (WA) coal zone in the Powder River Basin of Wyoming and Montana is plentiful, clean, and compliant with EPA emissions standards. This coal is considered to be very desirable for development for use in electric power generation. The purpose of this NCRA study was to compile all available data relating to the Wyodak- Anderson coal, correlate the beds that make up the WA coal zone, create digital files pertaining to the study area and the WA coal, and produce a variety of reports on various aspects of the assessed coal unit. This report contains preliminary calculations of coal resources for the WA coal zone and is one of many products of the NCRA study. Coal resource calculations in this report were produced using both public and confidential data from many sources. The data was manipulated using a variety of commercially available software programs and several custom programs. A general description of the steps involved in producing the resource calculations is described in this report.

  5. Preliminary report on the clay mineralogy of the Upper Devonian Shales in the southern and middle Appalachian Basin

    USGS Publications Warehouse

    Hosterman, John W.; Loferski, Patricia J.

    1978-01-01

    The distribution of kaolinite in parts of the Devonian shale section is the most significant finding of this work. These shales are composed predominately of 2M illite and illitic mixed-layer clay with minor amounts of chlorite and kaolinite. Preliminary data indicate that kaolinite, the only allogenic clay mineral, is present in successively older beds of the Ohio Shale from south to north in the southern and middle parts of the Appalachian basin. This trend in the distribution of kaolinite shows a paleocurrent direction to the southwest. Three well-known methods of preparing the clay fraction for X-ray diffraction analysis were tested and evaluated. Kaolinite was not identified in two of the methods because of layering due to differing settling rates of the clay minerals. It is suggested that if one of the two settling methods of sample preparation is used, the clay film be thin enough for the X-ray beam to penetrate the entire thickness of clay.

  6. First ediacaran fauna occurrence in northeastern Brazil (jaibaras basin, ?ediacaran-cambrian): preliminary results and regional correlation.

    PubMed

    Barroso, Francisco R G; Viana, Maria Somlia S; de Lima Filho, Mario F; Agostinho, Sonia M O

    2014-09-01

    This study reports the first known occurrence of the Ediacaran fauna in northeastern Brazil (at Pacuj Municipality, northwestern state of Cear) and presents preliminary interpretations of its significance. Regional correlation indicates that the fossils originated in the Jaibaras Basin and that they may represent a new geological system. The depositional environment can be attributed to a fluviomarine system. Nine Ediacaran species can be identified, including members of pandemic groups (e.g., Charniodiscus arboreus Glaessner, 1959; ?Charniodiscus concentricus Ford, 1958; Cyclomedusa davidi Sprigg, 1947; Ediacaria flindersi Sprigg, 1947; and Medusinites asteroides Sprigg, 1949) and endemic groups (e.g., Kimberella quadrata Glaessner & Wade, 1966; Palaeophragmodictya reticulata Gehling & Rigby, 1996; Parvancorina minchami Glaessner, 1958; and Pectinifrons abyssalis Bamforth, Narbonne, Anderson, 2008). Three ichnogenera are also present: Arenicolites Salter, 1857; Palaeophycus Hall, 1987; and Planolites Nicholson, 1873. The relative age of the deposits is between ?Ediacaran and Cambrian, and the fauna resembles the White Sea Assemblage. The bioturbation presents typical unbranched Ediacaran ichnogenera with little depth in the substrate. This previously unknown occurrence of the Ediacaran fauna reinforces the importance of the state of Cear to Brazilian and global palaeontology. PMID:25140502

  7. Modeling fluid flow and heat transfer at Basin and Range faults: preliminary results for Leach hot springs, Nevada

    USGS Publications Warehouse

    López, Dina L.; Smith, Leslie; Storey, Michael L.

    1994-01-01

    The hydrothermal systems of the Basin and Range Province are often located at or near major range bounding normal faults. The flow of fluid and energy at these faults is affected by the advective transfer of heat and fluid from an to the adjacent mountain ranges and valleys, This paper addresses the effect of the exchange of fluid and energy between the country rock, the valley fill sediments, and the fault zone, on the fluid and heat flow regimes at the fault plane. For comparative purposes, the conditions simulated are patterned on Leach Hot Springs in southern Grass Valley, Nevada. Our simulations indicated that convection can exist at the fault plane even when the fault is exchanging significant heat and fluid with the surrounding country rock and valley fill sediments. The temperature at the base of the fault decreased with increasing permeability of the country rock. Higher groundwater discharge from the fault and lower temperatures at the base of the fault are favored by high country rock permabilities and fault transmissivities. Preliminary results suggest that basal temperatures and flow rates for Leach Hot Springs can not be simulated with a fault 3 km deep and an average regional heat flow of 150 mW/m2 because the basal temperature and mass discharge rates are too low. A fault permeable to greater depths or a higher regional heat flow may be indicated for these springs.

  8. Establishment of a hydrological monitoring network in a tropical African catchment: An integrated participatory approach

    NASA Astrophysics Data System (ADS)

    Gomani, M. C.; Dietrich, O.; Lischeid, G.; Mahoo, H.; Mahay, F.; Mbilinyi, B.; Sarmett, J.

    Sound decision making for water resources management has to be based on good knowledge of the dominant hydrological processes of a catchment. This information can only be obtained through establishing suitable hydrological monitoring networks. Research catchments are typically established without involving the key stakeholders, which results in instruments being installed at inappropriate places as well as at high risk of theft and vandalism. This paper presents an integrated participatory approach for establishing a hydrological monitoring network. We propose a framework with six steps beginning with (i) inception of idea; (ii) stakeholder identification; (iii) defining the scope of the network; (iv) installation; (v) monitoring; and (vi) feedback mechanism integrated within the participatory framework. The approach is illustrated using an example of the Ngerengere catchment in Tanzania. In applying the approach, the concept of establishing the Ngerengere catchment monitoring network was initiated in 2008 within the Resilient Agro-landscapes to Climate Change in Tanzania (ReACCT) research program. The main stakeholders included: local communities; Sokoine University of Agriculture; Wami Ruvu Basin Water Office and the ReACCT Research team. The scope of the network was based on expert experience in similar projects and lessons learnt from literature review of similar projects from elsewhere integrated with local expert knowledge. The installations involved reconnaissance surveys, detailed surveys, and expert consultations to identify best sites. First, a Digital Elevation Model, land use, and soil maps were used to identify potential monitoring sites. Local and expert knowledge was collected on flow regimes, indicators of shallow groundwater plant species, precipitation pattern, vegetation, and soil types. This information was integrated and used to select sites for installation of an automatic weather station, automatic rain gauges, river flow gauging stations, flow measurement sites and shallow groundwater wells. The network is now used to monitor hydro-meteorological parameters in collaboration with key stakeholders in the catchment. Preliminary results indicate that the network is working well. The benefits of this approach compared to conventional narrow scientific/technical approaches have been shown by gaining rapid insight into the hydrology of the catchment, identifying best sites for the instruments; and voluntary participation of stakeholders in installation, monitoring and safeguarding the installations. This approach has proved simple yet effective and yielded good results. Based on this experience gained in applying the approach in establishing the Ngerengere catchment monitoring network, we conclude that the integrated participatory approach helps to assimilate local and expert knowledge in catchments monitoring which consequently results in: (i) identifying best sites for the hydrologic monitoring; (ii) instilling the sense of ownership; (iii) providing security of the installed network; and (iv) minimizing costs for installation and monitoring.

  9. Preliminary Paleomagnetic Results From Tertiary Rocks of Sedimentary Basins in Northern Vietnam and Tectonic Implications

    NASA Astrophysics Data System (ADS)

    Zhao, X.; Liu, Z.; Le, K.; Zhao, Y.; Hoang, V.; Phan, D.

    2013-12-01

    The South China Sea (SCS) is a classical representative of western Pacific marginal seas and contains records of Cenozoic tectonic events of SE Asia. The SCS has been at the center stage of many first-order tectonic and paleoclimatic events since the Mesozoic. One clear way to evaluate the relationship between tectonic uplift and climate is to study the resulting changes in marginal sea strata. To this end, we will conduct an integrated paleomagnetic and stratigraphic investigation on Tertiary strata from Phu Tho and Yen Bai provinces, northern Vietnam to help understand the causal linkages among geological and tectonic events and their consequences related to the SCS evolution. We will collect paleomagnetic samples at sections where the most continuous, complete, and best preserved Eocene-Miocene successions. Standard paleomagnetic field tests, such as the fold, reversal, and conglomerate tests will be used to determine the relative age of the magnetization. In addition to detailed thermal and alternating field demagnetization and analysis, selected samples will also be subjected to several rock magnetic analyses to identify magnetic carriers in the rocks. In particular, the hysteresis parameters Jrs/Js and Hcr /Hc ratios will enable us to apply techniques for detecting low-temperature remagnetization of sedimentary rocks. Preliminary finding of this ongoing project will be presented.

  10. Catchment Classification and Services, Considering Societal Needs in Classification

    NASA Astrophysics Data System (ADS)

    Wagener, T.

    2008-12-01

    Hydrologists do not yet possess a generally accepted catchment classification system. A general framework for catchment classification should consider variability in relevant physical and behavioral characteristics, increasing human impacts on catchments, and the assumption that our climate is changing. Any classification system should explicitly account for uncertainty and have predictive power, rather than just being descriptive. A potential extension to catchment classification lies in the inclusion of catchment services and disservices, which would explicitly link hydrology to current and future societal issues. Such a framework can describe catchment climate and form to map these on catchment function (include partition, storage and release of water, energy and matter). Climate, form, and function can be described using indices, distributions, or even conceptual models; and uncertainty needs to be preserved in individual descriptors as well as in their mapping onto each other. Descriptors of catchment function are discussed as signatures of catchment behavior, which in turn are related to catchment services and disservices. This mapping ultimately provides predictive skill by constraining the expected function at ungauged locations, even under potential nonstationarity, through knowledge of form and/or climate. Establishing this framework would provide an organizing principle, create a common language, guide modeling and measurement efforts, provide constraints on predictions in ungauged basins, and allow estimates of environmental change impacts.

  11. Preliminary basin analysis of late Proterozoic-Cambrian post-rift strata, southeast Idaho thrust belt

    SciTech Connect

    Link, P.K.; Jansen, S.T.; Halimdihardja, P.; Lande, A.C.; Zahn, P.D.

    1987-08-01

    Strata of the Brigham Group in the Paris-Putnam plate of the southeastern Idaho thrust belt span the late Proterozoic-Cambrian boundary and consist of quartzose sandstone with subordinate pebble conglomerate and siltstone. The Brigham Group is overlain by fossiliferous Cambrian carbonate units that represent the transition from siliciclastic to carbonate deposition in the Cordilleran miogeocline. The Brigham Group contains four stratigraphic sequences bounded by regional disconformities. The lower sequence includes strata below the Brigham group (upper member, Pocatello Formation), plus the Papoose Creek Formation and most of the overlying Caddy Canyon Quartzite. This sequence is dominantly marine with shoreface and braided fluvial strata at the top. The first sequence is overlain disconformably by offshore sub-wave base marine strata of the upper Caddy Canyon Quartzite and Inkom Formation. This second sequence is entirely marine and is composed dominantly of siltstone with sandstone-filled channels. The third sequence comprises the Mutual Formation, an entirely braided fluvial and lacustrine unit. The fourth sequence (Sauk sequence) locally overlies the Mutual Formation with an erosional unconformity and consists of dominantly marine strata of the Camelback Mountain Quartzite, Gibson Jack Formation, Windy Pass Argillite, Twin Knobs Formation, and Sedgwick peak Quartzite. Correlations of these sequences to the McCoy Creek Group of eastern Nevada suggests uniform conditions of sea level and subsidence across the late Proterozoic-Cambrian Cordilleran miogeocline. This preliminary synthesis suggests the Brigham and McCoy Creek Groups are post-rift deposits, as indicated by regional persistence of facies, paleocurrents, and quartzose petrology.

  12. A preliminary assessment of sources of nitrate in springwaters, Suwannee River basin, Florida

    USGS Publications Warehouse

    Katz, B.G.; Hornsby, H.D.

    1998-01-01

    A cooperative study between the Suwannee River Water Management District (SRWMD) and the U.S. Geological Survey (USGS) is evaluating sources of nitrate in water from selected springs and zones in the Upper Floridan aquifer in the Suwannee River Basin. A multi-tracer approach, which consists of the analysis of water samples for naturally occurring chemical and isotopic indicators, is being used to better understand sources and chronology of nitrate contamination in the middle Suwannee River region. In July and August 1997, water samples were collected and analyzed from six springs and two wells for major ions, nutrients, and dissolved organic carbon. These water samples also were analyzed for environmental isotopes [18O/16O, D/H, 13C/12C, 15N/14N] to determine sources of water and nitrate. Chlorofluorocarbons (CCl3F, CCl2F2, and C2Cl3F3) and tritium (3H) were analyzed to assess the apparent ages (residence time) of springwaters and water from the Upper Floridan aquifer. Delta 15N-NO3 values in water from the six springs range from 3.94 per mil (Little River Springs) to 8.39 per mil (Lafayette Blue Spring). The range of values indicates that nitrate in the sampled springwaters most likely originates from a mixture of inorganic (fertilizers) and organic (animal wastes) sources, although the higher delta 15N-NO3 value for Lafayette Blue Spring indicates that an organic source of nitrogen is likely at this site. Water samples from the two wells sampled in Lafayette County have high delta 15N-NO3 values of 10.98 and 12.1 per mil, indicating the likelihood of an organic source of nitrate. These two wells are located near dairy and poultry farms, where leachate from animal wastes may contribute nitrate to ground water. Based on analysis of chlorofluorocarbons in ground water, the mean residence time of water in springs ranges from about 12 to 25 years. Chlorofluorocarbons-modeled recharge dates for water samples from the two shallow zones in the Upper Floridan aquifer range from 1985 to 1989.

  13. Catchment Classification: Connecting Climate, Structure and Function

    NASA Astrophysics Data System (ADS)

    Sawicz, K. A.; Wagener, T.; Sivapalan, M.; Troch, P. A.; Carrillo, G. A.

    2010-12-01

    Hydrology does not yet possess a generally accepted catchment classification framework. Such a classification framework needs to: [1] give names to things, i.e. the main classification step, [2] permit transfer of information, i.e. regionalization of information, [3] permit development of generalizations, i.e. to develop new theory, and [4] provide a first order environmental change impact assessment, i.e., the hydrologic implications of climate, land use and land cover change. One strategy is to create a catchment classification framework based on the notion of catchment functions (partitioning, storage, and release). Results of an empirical study presented here connects climate and structure to catchment function (in the form of select hydrologic signatures), based on analyzing over 300 US catchments. Initial results indicate a wide assortment of signature relationships with properties of climate, geology, and vegetation. The uncertainty in the different regionalized signatures varies widely, and therefore there is variability in the robustness of classifying ungauged basins. This research provides insight into the controls of hydrologic behavior of a catchment, and enables a classification framework applicable to gauged and ungauged across the study domain. This study sheds light on what we can expect to achieve in mapping climate, structure and function in a top-down manner. Results of this study complement work done using a bottom-up physically-based modeling framework to generalize this approach (Carrillo et al., this session).

  14. Runoff Responses to Forest Thinning at Plot and Catchment Scales in a Headwater Catchment Draining Japanese Cypress Forest

    EPA Science Inventory

    We examined the effect of forest thinning on runoff generation at plot and catchment scales in headwater basins draining a Japanese cypress (Chamaecyparis obtusa) forest. We removed 58.3% of the stems (corresponding to 43.2% of the basal area) in the treated headwater basin (catc...

  15. Towards sediment residence time in a Himalayan catchment? Insights from paired in-situ 14C and 10Be measurements in river sands

    NASA Astrophysics Data System (ADS)

    Lupker, M.; Hippe, K.; Wacker, L.; Wieler, R.

    2014-12-01

    Cosmogenic nuclides in detrital river sediments have been widely applied to derive denudation rates and sediment fluxes across entire catchments. Nuclides, such as 10Be, allow the derivation of denudation rates integrated over several hundreds to thousands of years, but single isotopic systems often provide little information on the intricate dynamics that control the export of sediments from catchments. The quantification of sediment storage and recycling within catchments is nevertheless crucial for a better understanding of the variability of sediments fluxes and their implication for landscape evolution. The paired measurement of 10Be along with cosmogenic, in-situ 14C in river sediments may provide new insides into sediment dynamics over kyr time scales for which other nuclides are not suitable [1,2]. In an effort to better understand the sediment dynamics in active orogens we combine in-situ 14C and 10Be measurements from the Kosi basin in eastern Nepal (~53 000 km2). Our preliminary 14C/10Be data shows apparent burial/storage ages of 14 to 21 kyr in the sediments currently exported by the river. These elevated burial ages suggest a larger storage component than previously thought in these catchments, even though possible biases associated to the use of 14C/10Be in sediments as burial chronometer have to be considered: First, the short half-life of 14C cannot be neglected and hence basin wide denudation cannot be considered as a simple mixing of sediments from individually eroding surfaces, introducing bias towards higher apparent burial ages in most settings. Second, in steep environments, sediments supplied by deep-seated landslides carry a buried signature that should not be confounded with sediment storage in the catchment. The importance of both biases needs to be quantified carefully, before basin-wide storage can be quantified. [1] Lauer & Willenbring, 2010 - JGR-Earth, vol. 115, F04018. [2] Hippe et al., 2012 - Geomorphology, vol. 179, pp. 58-70.

  16. Impact and sustainability of low-head drip irrigation kits, in the semi-arid Gwanda and Beitbridge Districts, Mzingwane Catchment, Limpopo Basin, Zimbabwe

    NASA Astrophysics Data System (ADS)

    Moyo, Richard; Love, David; Mul, Marloes; Mupangwa, Walter; Twomlow, Steve

    Resource-poor smallholder farmers in the semi-arid Gwanda and Beitbridge districts face food insecurity on an annual basis due to a combination of poor and erratic rainfall (average 500 mm/a and 345 mm/a, respectively, for the period 1970-2003) and technologies inappropriate to their resource status. This impacts on both household livelihoods and food security. In an attempt to improve food security in the catchment a number of drip kit distribution programmes have been initiated since 2003 as part of an on-going global initiative aimed at 2 million poor households per year. A number of recent studies have assessed the technical performance of the drip kits in-lab and in-field. In early 2005 a study was undertaken to assess the impacts and sustainability of the drip kit programme. Representatives of the NGOs, local government, traditional leadership and agricultural extension officers were interviewed. Focus group discussions with beneficiaries and other villagers were held at village level. A survey of 114 households was then conducted in two districts, using a questionnaire developed from the output of the interviews and focus group discussions. The results from the study showed that the NGOs did not specifically target the distribution of the drip kits to poor members of the community (defined for the purpose of the study as those not owning cattle). Poor households made up 54% of the beneficiaries. This poor targeting of vulnerable households could have been a result of conditions set by some implementing NGOs that beneficiaries must have an assured water source. On the other hand, only 2% of the beneficiaries had used the kit to produce the expected 5 harvests over the 2 years, owing to problems related to water shortage, access to water and also pests and diseases. About 51% of the respondents had produced at least 3 harvests and 86% produced at least 2 harvests. Due to water shortages during the dry season 61% of production with the drip kit occurred during the wet season. This suggests that most households use the drip kits as supplementary irrigation. Conflicts between beneficiaries and water point committees or other water users developed in some areas especially during the dry season. The main finding from this study was that low cost drip kit programs can only be a sustainable intervention if implemented as an integral part of a long-term development program, not short-term relief programs and the programme should involve a broad range of stakeholders. A first step in any such program, especially in water scarce areas such as Gwanda and Beitbridge, is a detailed analysis of the existing water resources to assess availability and potential conflicts, prior to distribution of drip kits.

  17. Isotopic monitoring (2H, 18O) of the St. Lawrence and Ottawa rivers between 1997 and 2003- Links with interannual climatic variability and hydrological processes in their catchment basins

    NASA Astrophysics Data System (ADS)

    Myre, A.; Hillaire-Marcel, C.

    2004-05-01

    This study based on a water isotope (18O and 2H) monitoring of the St. Lawrence and Ottawa rivers (Canada) is a contribution to the international IAEA project: Isotopes tracing of hydrologic processes in large river basins [Gibson et al., 2002. EOS 83: 613 et p.]. Sampling of the St. Lawrence and Ottawa river waters started in 1997, on a biweekly to weekly basis. Monitoring stations are located at Montreal (i.e., at the outlet of the Great Lakes), Quebec City (the estuary of the St. Lawrence) and at the Carillon hydroelectric dam, near the outlet of a major tributary, the Ottawa River into the St. Lawrence itself. The goal of the study was to examine the seasonal and interannual variability of isotopic signatures of the St. Lawrence and Ottawa rivers, in relation notably with interannual climatic variations, and seasonal hydrologic processes in the watershed (summer evaporation, snowmelt, transit time of precipitation signals into runoff). Waters sampled at the three stations depict distinct isotopic compositions. At Montreal, relatively stable isotopic composition are observed with a mean weighted annual value of -54 % for 2H and -7.1 % for 18O. The Ottawa River water at Carillon also displays stable isotopic compositions but much lighter values (weighted mean annual values: -80 % for 2H and -10.8 % for 18O). Finally, isotopic compositions at Quebec City are intermediate between those of Montreal and Carillon, but show a much larger variability. They reflect mixing between the heavy isotope enriched Great Lakes water, the lighter water from the Ottawa River, and highly variable inputs from smaller tributaries (from the Laurentides and Appalachian mountains). The mean weighted isotopic compositions at Quebec City are -65 % and -8.6 %, respectively for 2H and 18O). Evaporative enrichment, in particular during low water level episodes, seem to be more important in the Ottawa River catchment than in the Great Lakes basin, based on a comparison of isotopic clusters at Montreal and Carillon (figure 1). Relatively strongly correlated relationships are observed between isotopic compositions at the estuary of the St. Lawrence River (Quebec) and hydrologic variables such as water discharge. The best fit follows the equation : 2HQUEBEC = -1.9E-03 * QQUEBEC - 41.9, R2= 0.59. Such a relationship leads us to conclude that some properties of the regional hydrology can be relatively well described by stable isotope systematics. In contradiction, air temperatures are not well correlated with isotopic signatures partly because of lag times between them in relation to transit time of precipitation signal into runoff. A comparison of isotopic values in precipitation to those of runoff gives an estimate of the mean transfer time of water from the catchment to the river estuary. For summer heavy isotope enriched, but scarcer precipitation, a transit time of approximately 3 months is observed, whereas in winter, it can be as long as 4 to 5 months due to the residence time of winter precipitation in the snowcover. The assessment of the interannual variability of the St. Lawrence River isotopic system will require a better estimate of the isotopic inprint from small tributaries (that drain isotopically buffered ground waters, particularly in winter). Data are presently at processing stage.

  18. Diatoms as a fingerprint of sub-catchment contributions to meso-scale catchment runoff

    NASA Astrophysics Data System (ADS)

    Klaus, Julian; Wetzel, Carlos E.; Martinez-Carreras, Nuria; Ector, Luc; Pfister, Laurent

    2014-05-01

    In recent years, calls were made for new eco-hydrological approaches to improve understanding of hydrological processes. Recently diatoms, one of the most common and diverse algal groups that can be easily transported by flowing water due to their small size (~10-200 µm), were used to detect the onset and cessation of surface runoff to small headwater streams and constrain isotopic and hydro-chemical hydrograph separation methods. While the method showed its potential in the hillslope-riparian zone-stream continuum of headwater catchments, the behavior of diatoms and their use for hydrological process research in meso-scale catchments remains uncertain. Diatoms can be a valuable support for isotope and hydro-chemical tracer methods when these become ambiguous with increasing scale. Distribution and abundance of diatom species is controlled by various environmental factors (pH, soil type, moisture conditions, exposition to sunlight, etc.). We therefore hypothesize that species abundance and composition can be used as a proxy for source areas. This presentation evaluates the potential for diatoms to trace source-areas in the nested meso-scale Attert River basin (250 km2, Luxembourg, Europe). We sampled diatom populations in streamwater during one flood event in Fall 2011 in 6 sub-catchments and the basin outlet - 17 to 28 samples/catchment for the different sampling locations. Diatoms were classified and counted in every individual sample. In total more than 400 diatom species were detected. Ordination analysis revealed a clear distinction between communities sampled in different sub-catchments. The species composition at the catchment outlet reflects a mixing of the diatom composition originating from different sub-catchments. This data suggests that diatoms indeed can reflect the geographic origin of stream water at the catchment outlet. The centroids of the ordination analysis might be linked to the physiographic characteristics (geology and land use) of the catchments. In a next step we will increase sample size of catchments to further evaluate if these distinct species assemblages are characteristic for different physiographic units and can indeed unambiguously trace catchment source areas. We will compare the results with classical source area hydrograph separations.

  19. Calculating specific catchment area

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2011-07-01

    Specific catchment area, defined as the area of land upslope of a width of contour, divided by the contour width, is a commonly used quantity in hydrology to describe complex terrain for analyzing water flow on hill slopes; it can be a surrogate for water discharge per unit flow width. Although specific catchment area is important in hydrological, ecological, and geological studies, it can be difficult to estimate. Gallant and Hutchinson provide a simple differential equation that describes the rate of change of specific catchment area along a flow path. The equation can be directly integrated to calculate specific catchment area at any point on a digital elevation model. The method avoids use of catchment area and width estimates, which have errors. Although the method is more computationally intense than most methods for calculating specific catchment area, it can be used as a reference against which other methods can be tested. (Water Resources Research, doi:10.1029/2009WR008540, 2011)

  20. Calculating specific catchment area

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2011-07-01

    Specific catchment area, defined as the area of land upslope of a width of contour, divided by the contour width, is a commonly used quantity in hydrology to describe complex terrain for analyzing water flow on hill slopes; it can be a surrogate for water discharge per unit flow width. Although specific catchment area is important in hydrological, ecological, and geological studies, it can be difficult to estimate. Gallant and Hutchinson provide a simple differential equation that describes the rate of change of specific catchment area along a flow path. The equation can be directly integrated to calculate specific catchment area at any point on a digital elevation model. The method avoids use of catchment area and width estimates, which have errors. Although the method is more computationally intense than most methods for calculating specific catchment area, it can be used as a reference against which other methods can be tested. (Water Resources Research, doi:10.1029/ 2009WR008540, 2011)

  1. Preliminary analysis of the role of lake basin morphology on the modern diatom flora in the Ruby Mountains and East Humboldt Range, Nevada, USA

    USGS Publications Warehouse

    Starratt, Scott W.

    2014-01-01

    As paleolimnologists, we often look at the world through a 5-cm-diameter hole in the bottom of a lake, and although a number of studies have shown that a single core in the deepest part of a lake does not necessarily reflect the entire diatom flora, time and money often limit our ability to collect more than one core from a given site. This preliminary study is part of a multidisciplinary research project to understand Holocene climate variability in alpine regions of the Great Basin, and ultimately, to compare these high elevation records to the better studied pluvial records from adjacent valleys, in this case, the Ruby Valley.

  2. Preliminary results of the Cloud-Aerosol Interaction Measurements (CLAIM) 2007 campaign on the Amazon Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Correia, A. L.; Fernandez-Borda, R.; Martins, J. V.

    2007-12-01

    Clouds and precipitation play an important role on Earth's radiation budget, water and hydrological cycles, as well as energy cycles through latent heat release in the atmosphere. Under several aspects the interaction between aerosols and clouds is still a poorly understood process, and one reason for this is the lack of experimental observations to characterize the evolution of cloud microphysical structure. An instrumentation suite was put together to assess these issues. The Cloud Scanner is a scanning radiometer composed of 2 wavelengths in the near infrared (2.10 and 2.25 ?m) used for the separation between ice and water, and 3 wavelengths in the thermal infrared (8, 11 and 12 ?m) for the measurement of cloud brightness temperature, cirrus properties and water vapor correction. The Rainbow Camera is a multiangle imaging polarimeter with the wavelengths 0.47, 0.55, 0.66, 0.76, 0.87, and 0.91 ?m, with 60 degrees FOV, used to retrieve droplet effective radii and distribution width. Both instruments were integrated onto a research aircraft for a field campaign over the Brazilian Amazon Basin from Sep-Oct 2007 under varying conditions of aerosol loading and cloud type, development stages, and cover area. The preliminary results obtained include real-time mappings of ice/water separation for clouds, with temperature profiles allowing for the retrieval of glaciation levels for a variety of cloud developmental stages and aerosol loadings, including deep convective cumulus clouds and/or high aerosol content. Vertical profiles of effective radius can be obtained using the measurements in 2.10 ?m as entries in a look up table from a 3D radiative transfer model for the cloud field. The post-processed polarimeter measurements allow retrieving a polarized reflectance signal from which one can derive effective radii and distribution widths of droplets for clouds in the observed scenes. These results help understanding and quantifying the effects of cloud-aerosol interactions and their consequences for cloud microphysics.

  3. PRELIMINARY DATA REPORT: HUMATE INJECTION AS AN ENHANCED ATTENUATION METHOD AT THE F-AREA SEEPAGE BASINS, SAVANNAH RIVER SITE

    SciTech Connect

    Millings, M.

    2013-09-16

    A field test of a humate technology for uranium and I-129 remediation was conducted at the F-Area Field Research Site as part of the Attenuation-Based Remedies for the Subsurface Applied Field Research Initiative (ABRS AFRI) funded by the DOE Office of Soil and Groundwater Remediation. Previous studies have shown that humic acid sorbed to sediments strongly binds uranium at mildly acidic pH and potentially binds iodine-129 (I-129). Use of humate could be applicable for contaminant stabilization at a wide variety of DOE sites however pilot field-scale tests and optimization of this technology are required to move this technical approach from basic science to actual field deployment and regulatory acceptance. The groundwater plume at the F-Area Field Research Site contains a large number of contaminants, the most important from a risk perspective being strontium-90 (Sr-90), uranium isotopes, I-129, tritium, and nitrate. Groundwater remains acidic, with pH as low as 3.2 near the basins and increasing to the background pH of approximately 5at the plume fringes. The field test was conducted in monitoring well FOB 16D, which historically has shown low pH and elevated concentrations of Sr-90, uranium, I-129 and tritium. The field test included three months of baseline monitoring followed by injection of a potassium humate solution and approximately four and half months of post monitoring. Samples were collected and analyzed for numerous constituents but the focus was on attenuation of uranium, Sr-90, and I-129. This report provides background information, methodology, and preliminary field results for a humate field test. Results from the field monitoring show that most of the excess humate (i.e., humate that did not sorb to the sediments) has flushed through the surrounding formation. Furthermore, the data indicate that the test was successful in loading a band of sediment surrounding the injection point to a point where pH could return to near normal during the study timeframe. Future work will involve a final report, which will include data trends, correlations and interpretations of laboratory data.

  4. Concentration and mineralogical residence of elements in rich oil shales of the Green River Formation, Piceance Creek basin, Colorado, and the Uinta Basin, Utah - A preliminary report

    USGS Publications Warehouse

    Desborough, G.A.; Pitman, J.K.; Huffman, C., Jr.

    1976-01-01

    Ten samples from drillcore of two rich oil-shale beds from the Parachute Creek Member of the Eocene Green River Formation, Piceance Creek basin, Colorado, and Uinta Basin, Utah, were analyzed for 37 major, minor, and trace elements. For 23 of these elements, principal mineralogical residence is established or suggested and such studies may provide data which are useful for predicting the kinds and amounts of elements and compounds that might be released into the environment by oil-shale mining operations. ?? 1976.

  5. Relations between hydrological and landscape indicators for headwater catchment similarity study - A way to extrapolate hydrologic behaviour of elementary catchments at regional extent, Languedoc Roussillon (southern France).

    NASA Astrophysics Data System (ADS)

    Crabit, A.; Colin, F.; Lagacherie, P.

    2009-04-01

    On a regional extent, there is a need of acquiring hydrological knowledge under elementary ungauged basins because of their importance in agricultural practices management. On such extent, we note a lack of information concerning catchment hydrological behaviour and we meet high spatiotemporal heterogeneities of rainfall repartition, soils, vegetation, land use and agricultural practices. This study tests the hypothesis of a relation between landscape characteristics and hydrology behaviour and propose a methodology that allows extrapolating hydrological response of Mediterranean elementary catchments on a regional extent from representative sampled catchments. The methodology is based on a coupled field observations-modelling approach aiming to define statistical relations between hydrological and landscape indicators. Taking into account the hypothesis that two catchments, which look similar from their physical properties, have a similar hydrologic response, we are able to predict hydrological behaviour with a given uncertainty on ungauged elementary watersheds. The current study is conducted on 14 headwater elementary catchments (1km²) located in the Mediterranean region Languedoc-Roussillon, Southern of France. Each catchment is equipped with a light device composed by a rain gauge and a limnimetric station. Due to the Mediterranean climate particularities (quick and intensive storms), catchment's hydrology is studied at the event scale. Based on observed data the following methodology to analyse hydrological similarities is: (i) to define, landscape and hydrological indicators considering a perceptual model of catchment function, (ii) to compare catchments from those indicators to establish a classification, (iii) to improve catchment similarities by using distributed hydrologic modelling on semi-virtual catchments which are synthetics catchments distorted from real ones (by changing hydrographic network density, land use, soil properties…) In this poster, we will show results concerning landscape indicators and hydrological catchment behaviour, obtained during the field observations period, to highlight catchment hydrological similarities. Those results will be completed with few semi-virtual basins cases, defined from a distributed hydrologic modelling approach.

  6. Solid discharge and landslide activity at basin scale

    NASA Astrophysics Data System (ADS)

    Ardizzone, F.; Guzzetti, F.; Iadanza, C.; Rossi, M.; Spizzichino, D.; Trigila, A.

    2012-04-01

    This work presents a preliminary analysis aimed at understanding the relationship between landslide sediment supply and sediment yield at basin scale in central and southern Italy. A database of solid discharge measurements regarding 116 gauging stations, located along the Apennines chain in Italy, has been compiled by investigating the catalogues, named Annali Idrologici, published by Servizio Idrografico e Mareografico Italiano in the period from 1917 to 1997. The database records several information about the 116 gauging stations, and especially reports the sediment yield monthly measurements (103 ton) and the catchments area (km2). These data have been used to calculate the average solid yield and the normalized solid yield for each station in the observation period. The Italian Landslide Inventory (Progetto IFFI) has been used to obtained the size of the landslides, in order to estimate the landslide mobilization rates. The IFFI Project funded by the Italian Government is realized by ISPRA (Italian National Institute for Environmental Protection and Research - Geological Survey of Italy) in partnership with the 21 Regions and Self Governing Provinces. 21 of the 116 gauging stations and the related catchments have been selected on the basis of the length of the solid discharge observation period and excluding the catchments with dams located upstream the stations. The landslides inside the selected catchments have been extracted from the IFFI inventory, calculating the planimetric area of each landslide. Considering both the shallow and deep landslides, the landslide volume has been estimated using an empirical power law relation (landslide area vs. volume). The total landslide volume in the study areas and the average sediment yield measured at the gauging stations have been compared, analysing the behaviour of the basins which drainage towards the Tyrrhenian sea and the basins which drainage towards the Adriatic sea.

  7. Modeling of facade leaching in urban catchments

    NASA Astrophysics Data System (ADS)

    Coutu, S.; Del Giudice, D.; Rossi, L.; Barry, D. A.

    2012-12-01

    Building facades are protected from microbial attack by incorporation of biocides within them. Flow over facades leaches these biocides and transports them to the urban environment. A parsimonious water quantity/quality model applicable for engineered urban watersheds was developed to compute biocide release from facades and their transport at the urban basin scale. The model couples two lumped submodels applicable at the basin scale, and a local model of biocide leaching at the facade scale. For the facade leaching, an existing model applicable at the individual wall scale was utilized. The two lumped models describe urban hydrodynamics and leachate transport. The integrated model allows prediction of biocide concentrations in urban rivers. It was applied to a 15 km2urban hydrosystem in western Switzerland, the Vuachère river basin, to study three facade biocides (terbutryn, carbendazim, diuron). The water quality simulated by the model matched well most of the pollutographs at the outlet of the Vuachère watershed. The model was then used to estimate possible ecotoxicological impacts of facade leachates. To this end, exceedance probabilities and cumulative pollutant loads from the catchment were estimated. Results showed that the considered biocides rarely exceeded the relevant predicted no-effect concentrations for the riverine system. Despite the heterogeneities and complexity of (engineered) urban catchments, the model application demonstrated that a computationally "light" model can be employed to simulate the hydrograph and pollutograph response within them. It thus allows catchment-scale assessment of the potential ecotoxicological impact of biocides on receiving waters.

  8. Preliminary vitrinite and bitumen reflectance, total organic carbon, and pyrolysis data for samples from Upper and Lower Cretaceous strata, Maverick Basin, south Texas

    USGS Publications Warehouse

    Hackley, Paul C.; Dennen, Kristin O.; Gesserman, Rachel M.; Ridgley, Jennie L.

    2009-01-01

    The Lower Cretaceous Pearsall Formation, a regionally occurring limestone and shale interval of 500-600-ft maximum thickness (Rose, 1986), is being evaluated as part of an ongoing U.S. Geological Survey (USGS) assessment of undiscovered hydrocarbon resources in onshore Lower Cretaceous strata of the northern Gulf of Mexico. The purpose of this report is to release preliminary vitrinite and bitumen reflectance, total organic carbon, and pyrolysis data for Pearsall Formation, Glen Rose Formation, Hosston Formation, Austin Group, and Eagle Ford Group samples from the Maverick Basin in south Texas in order to aid in the characterization of these strata in this area. The preliminary nature of this report and the data contained herein reflect that the assessment and characterization of these samples is a work currently in progress. Pearsall Formation subdivisions are, in ascending stratigraphic order, the Pine Island Shale, James Limestone, and Bexar Shale Members (Loucks, 2002). The Lower Cretaceous Glen Rose Formation is also part of the USGS Lower Cretaceous assessment and produces oil in the Maverick Basin (Loucks and Kerans, 2003). The Hosston Formation was assessed by the USGS for undiscovered oil and gas resources in 2006 (Dyman and Condon, 2006), but not in south Texas. The Upper Cretaceous Austin Group is being assessed as part of the USGS assessment of undiscovered hydrocarbon resources in the Upper Cretaceous strata of the northern Gulf of Mexico and, along with the Upper Cretaceous Eagle Ford Group, is considered to be an important source rock in the Smackover-Austin-Eagleford Total Petroleum System (Condon and Dyman, 2006). Both the Austin Group and the Eagle Ford Group are present in the Maverick Basin in south Texas (Rose, 1986).

  9. The contribution of sea-level rise to flooding in large river catchments

    NASA Astrophysics Data System (ADS)

    Thiele-Eich, I.; Hopson, T. M.; Gilleland, E.; Lamarque, J.; Hu, A.; Simmer, C.

    2012-12-01

    Climate change is expected to both impact sea level rise as well as flooding. Our study focuses on the combined effect of climate change on upper catchment precipitation as well as on sea-level rise at the river mouths and the impact this will have on river flooding both at the coast and further upstream. We concentrate on the eight catchments of the Amazonas, Congo, Orinoco, Ganges/Brahmaputra/Meghna, Mississippi, St. Lawrence, Danube and Niger rivers. To assess the impact of climate change, upper catchment precipitation as well as monthly mean thermosteric sea-level rise at the river mouth outflow are taken from the four CCSM4 1 20th Century ensemble members as well as from six CCSM4 1 ensemble members for the RCP scenarios RCP8.5, 6.0, 4.5 and 2.6. Continuous daily time series for average catchment precipitation and discharge are available for each of the catchments. To arrive at a future discharge time series, we used these observations to develop a simple statistical hydrological model which can be applied to the modelled future upper catchment precipitation values. The analysis of this surrogate discharge time series alone already yields significant changes in flood return levels as well as flood duration. Using the geometry of the river channel, the backwater effect of sea-level rise is incorporated in our analysis of both flood frequencies and magnitudes by calculating the effective additional discharge due to the increase in water level at the river mouth outflow, as well as its tapering impact upstream. By combining these effects, our results focus on the merged impact of changes in extreme precipitation with increases in river height due to sea-level rise at the river mouths. Judging from our preliminary results, the increase in effective discharge due to sea-level rise cannot be neglected when discussing late 21st century flooding in the respective river basins. In particular, we find that especially in countries with low elevation gradient, flood characteristics are impacted by changes in sea-level rise as far inland as 150 kilometers. Therefore, a larger population than the coastal inhabitants alone are exposed to risks of further projected increases of sea-level rise. A prime example for a megacity greatly put at risk by this is Dhaka City in Bangladesh, with a population of roughly 14 million people.

  10. Data-driven catchment classification: application to the pub problem

    NASA Astrophysics Data System (ADS)

    di Prinzio, M.; Castellarin, A.; Toth, E.

    2011-06-01

    A promising approach to catchment classification makes use of unsupervised neural networks (Self Organising Maps, SOM's), which organise input data through non-linear techniques depending on the intrinsic similarity of the data themselves. Our study considers ∼300 Italian catchments scattered nationwide, for which several descriptors of the streamflow regime and geomorphoclimatic characteristics are available. We compare a reference classification, identified by using indices of the streamflow regime as input to SOM, with four alternative classifications, which were identified on the basis of catchment descriptors that can be derived for ungauged basins. One alternative classification adopts the available catchment descriptors as input to SOM, the remaining classifications are identified by applying SOM to sets of derived variables obtained by applying Principal Component Analysis (PCA) and Canonical Correlation Analysis (CCA) to the available catchment descriptors. The comparison is performed relative to a PUB problem, that is for predicting several streamflow indices in ungauged basins. We perform an extensive cross-validation to quantify nationwide the accuracy of predictions of mean annual runoff, mean annual flood, and flood quantiles associated with given exceedance probabilities. Results of the study indicate that performing PCA and, in particular, CCA on the available set of catchment descriptors before applying SOM significantly improves the effectiveness of SOM classifications by reducing the uncertainty of hydrological predictions in ungauged sites.

  11. Flash flood warning in mountainaious areas: using damages reports to evaluate the method at small ungauged catchments

    NASA Astrophysics Data System (ADS)

    Defrance, Dimitri; Javelle, Pierre; Ecrepont, Stphane; Andreassian, Vazken

    2013-04-01

    In Europe, flash floods mainly occur in the Mediterranean area on small catchments with a short concentration time. Anticipating this kind of events is a major issue in order to reduce the resulting damages. But for many of the impacted catchments, no data are available to calibrate and evaluate hydrological models. In this context, the aims of this study is to develop and evaluate a warning method for the Southern French Alps. This area is of particular interest, because it regroups different hydrological regimes, from purely Mediterranean to purely Alpine influences. Two main issues should be addressed: - How to define the hydrological model and its parameterization for an application in an ungauged context? - How to evaluate the final results on 'real' ungauged catchments? The first issue is a classic one. Using a 'observed' data set (154 streamflow stations with catchment areas ranging from 5 to 1000 km and distributed rainfall available on the 1997-2006 period), we developed a regional model specifically for the studied area. For this purpose, the AIGA method, initially developed for Mediterranean catchments was adapted, in order to take into account snowmelt and to produce baseflows. Then, different parameterizations were tested, derived from different simple regionalisation techniques: - the same parameters set for the whole area defined as the median of the local calibrated parameters; - the same technique as the previous case, but by considering different sub-areas, defined as "hydro-climatically" homogeneous by previous studies; - and finally the neighbour's method. The second issue is more original. Indeed, in most studies the final evaluation is done using gauged stations as they were 'ungauged', ie keeping the at-site discharge data only for validation ant not for calibration. The main disadvantage of this approach is that the evaluation is made at the scale of the gauged catchments, which are in general greater than the catchments impacted by flash floods. Furthermore, many events are missed, since flash floods can occur very locally. In this study, we try to evaluate the results on observations collected by witnesses on 'real' ungauged catchments. The proposed method consists to use an historical data-base of flood damages reports. These data have been collected by local authorities (RTM). Finally, 139 ungauged locations were considered, where we simulated discharges for the entire 1997-2006 period. The comparison of these modelled discharges with the occurrence of an observed discharge makes it possible to determine a local 'modelled' discharge threshold above it most of the damages are observed. The pertinence of this threshold (and consequently of the model used for the simulation) is assessed by considering classical contingency statistics: probability of detection (POD), false alarm rate (FAR) and critical success index (CSI). The main advantage of this historical approach is the availability of many events in the database on very small catchments (50% less than 20 km). The preliminary results show that on gauged basins, the base flow and the snowmelt added modules improve the performance of the AIGA method when locally calibrated. But when results are applied on real ungauged catchments, improvements become less obvious, with a small advantage for neighbour's method. These results shows the difficulty arising with ungauged catchments, specially when target catchments are smaller than the gauged 'parents'. It also illustrates the interest of the damages database used as 'proxy' data to investigate the model performances at smaller scales. This work has been done in the framework of the RHYTMME project, with the financial support of the European Union, the Provence-Alpes-Cte d'Azur Region and the French Ministry in charge of Ecology.

  12. Data-driven catchment classification: combining linear and non-linear approaches to improve hydrological predictions in ungauged catchments

    NASA Astrophysics Data System (ADS)

    Di Prinzio, M.; Castellarin, A.; Toth, E.

    2012-04-01

    A promising approach to catchment classification makes use of unsupervised neural networks (Self Organising Maps, SOM's), which organise input data through non-linear techniques depending on the intrinsic similarity of the data themselves. Our study considers ~300 Italian catchments scattered nationwide, for which several descriptors of the streamflow regime and geomorphoclimatic characteristics are available. We compare a reference classification, identified by using indices of the streamflow regime as input to SOM, with four alternative classifications, which were identified on the basis of catchment descriptors that can be derived for ungauged basins. One alternative classification adopts the available catchment descriptors as input to SOM, the remaining classifications are identified by applying SOM to sets of derived variables obtained by applying Principal Component Analysis (PCA) and Canonical Correlation Analysis (CCA) to the available catchment descriptors. The comparison is performed relative to a PUB problem, that is for predicting several streamflow indices in ungauged basins. We perform an extensive cross-validation to quantify nationwide the accuracy of predictions of mean annual runoff, mean annual flood, and flood quantiles associated with given exceedance probabilities. Results of the study indicate that performing PCA and, in particular, CCA on the available set of catchment descriptors before applying SOM significantly improves the effectiveness of SOM classifications by reducing the uncertainty of hydrological predictions in ungauged sites.

  13. Preliminary selection of storm-water basins suitable for infiltration of reclaimed water in Nassau County, Long Island, New York

    USGS Publications Warehouse

    Aronson, D.A.

    1976-01-01

    A survey was made of 205 storm-water basins south of the ground-water divide and north of Hempstead Turnpike in Nassau County, Long Island, N.Y., to determine which would be best suited for infiltration of reclaimed water. Selection depended on infiltration area, location with respect to the ground-water divide and to planned transmission mains, tendency to retain storm runoff, underlying lithology, and depth to water table. The total maximum infiltration area of 14 selected basins is 60.2 acres, or 2,620,900 square feet (0.24 square kilometers). If 5-foot (1.5-meter) -high partitions were constructed in the basins to divide each into approximately equal halves and reclaimed water were applied in half of each basin to a depth of 5 feet (1.5 meters), using an application-rest cycle, a total area of 25.2 acres (0.10 square kilometers) would be available for supplemental recharge; the remaining infiltration area could be used for disposal of storm runoff. (Woodard-USGS)

  14. Nanophytoplankton Diversity Across the Oligohaline Lake Pontchartrain Basin Estuary: A Preliminary Investigation Utlizing psbA Sequences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Lake Pontchartrain basin estuary is shallow, wind-driven and comprised of two large embayments (1645 km2). Salinities range from freshwater in the west to 8 ppt in the east near the Gulf of Mexico. Phytoplankton investigations spanning this salinity gradient or examining small photoautotrophs ar...

  15. Preliminary results of preimpoundment water-quality studies in the Tioga River Basin, Pennsylvania and New York

    USGS Publications Warehouse

    Ward, Janice R.

    1976-01-01

    Three impoundments have been proposed for the Tioga study area in Pennsylvania and New York. Two of the reservoirs, Tioga and Hammond Lakes, are presently under construction and will be completed in 1977. Cowanesque Lake is in the planning stages and will be started in the near future. The Tioga River and its major tributaries were sampled monthly from September 1973 to May 1975. Water quality in the Tioga River is degraded by acid-mine drainage entering the stream near Blossburg from both strip- and deep-mined areas. The stream supports few species of aquatic life from Blossburg to its confluence with Crooked Creek. Alkaline water of tributaries Mill Creek, Crooked Creek, and the Cowanesque River counteract the acidity carried downstream from Blossburg, and the water quality of the Tioga River gradually improves, supporting a more diversified population of fish and aquatic life. All of the streams in the Tioga River basin carry nutrients sufficient for algae blooms. Dissolved solids range from very high to moderately high throughout the basin. The Tioga River has high concentrations of sulfate and heavy metals, particularly iron and manganese. Dissolved oxygen was usually above 80 percent saturation and never dropped below 7.0 milligrams per liter throughout the basin. Relationships between selected water-quality parameters have been developed for the sampling stations throughout the basin. Downstream trends were also examined. (Woodard-USGS)

  16. Collaborative Adaptation Planning for Water Security: Preliminary Lessons, Challenges, and the Way Forward for Maipo Basin Adaptation Plan, Chile

    NASA Astrophysics Data System (ADS)

    Vicuna, S.; Scott, C. A.; Bonelli, S.; Bustos, E.; Meza, F. J.

    2014-12-01

    The Maipo basin holds 40% of Chile's total population and almost half of the country's Gross Domestic Product. The basin is located in the semiarid central region of the country and, aside from the typical pressures of growth in developing country basins, the Maipo river faces climate change impacts associated with a reduction in total runoff and changes in its seasonality. Surface water is the main water source for human settlements and economic activities including agriculture. In 2012 we started a research project to create a climate variability and climate change adaptation plan for the basin. The pillars of the plan are co-produced by researchers and a Scenario Building Team (SBT) with membership of relevant water and land use stakeholders (including from civil society, public and private sectors) in the basin. Following similar experiences in other regions in the world that have faced the challenges of dealing with long term planning under uncertainty, the project has divided the task of developing the plan into a series of interconnected elements. A critical first component is to work on the desired vision(s) of the basin for the future. In this regards, the "water security" concept has been chosen as a framework that accommodates all objectives of the SBT members. Understanding and quantifying the uncertainties that could affect the future water security of the basin is another critical aspect of the plan. Near and long term climate scenarios are one dimension of these uncertainties that are combined with base development uncertainties such as urban growth scenarios. A third component constructs the models/tools that allows the assessment of impacts on water security that could arise under these scenarios. The final critical component relates to the development of the adaptation measures that could avoid the negative impacts and/or capture the potential opportunities. After two years in the development of the adaptation plan a series of results has been achieved in all critical components that are presented here. The success in the process now poses a series of new challenges, most importantly: how to implement and monitor the evolution of the adaptation process.

  17. How old is upland catchment water?

    NASA Astrophysics Data System (ADS)

    Hofmann, Harald; Cartwright, Ian; Morgenstern, Uwe; Gilfedder, Benjamin

    2014-05-01

    Understanding the dynamics of water supply catchments is an essential part of water management. Upland catchments provide a continuous, reliable source of high quality water not only for some of the world's biggest cities, but also for agriculture and industry. Headwater streams control river flow in lowland agricultural basins as the majority of river discharge emerges from upland catchments. Many rivers are perennial and flow throughout the year, even during droughts. However, it is still unclear how reliable and continuous upland catchment water resources really are. Despite many efforts in upland catchment research, there is still little known about where the water is stored and how long it takes to travel through upper catchments. Resolving these questions is crucial to ensure that this resource is protected from changing land use and to estimate potential impacts from a changing climate. Previous research in this important area has been limited by existing measurement techniques. Knowledge to date has relied heavily on the use of variation in stable isotope signals to estimate the age and origin of water from upland catchments. The problem with relying on these measures is that as the water residence time increases, the variation in the stable isotope signal decreases. After a maximum period of four years, no variation can be detected This means that to date, the residence time in upland catchments is likely to have been vastly underestimated. Consequently, the proportion of water flow out of upland river catchments to the total river flow is also underestimated. Tritium (3H) combines directly with water molecules and enters the flow paths with the infiltrating water. Its half-life (12.32 years) makes it ideal to describe residence times in upper catchment reservoirs as it can theoretically measure water up to about 150 years old. The bomb pulse peak in the southern hemisphere was several orders of magnitude lower than in the northern hemisphere. Hence the Tritium activities in the southern hemisphere have long decayed down the natural background levels, which allows unique ages to be determined by single measurements. In this study major ion chemistry, stable isotopes and Tritium were determined at 2 locations and various stages of discharge (18 Tritium samples in between April 2013 and January 2014) in a first-order perennial stream draining a 7.3 km2 catchment in the Dandenong National Park, Melbourne, Australia. Even during major discharge event major ions and stable isotope data have little variation and Tritium activities remain low (1.4 to 1.8 TU) in comparison to local rainfall of ~ 3TU. Age estimations based on an exponential flow model are 15 to 25 years indicating that water draining from upland catchments is much older than we have previously estimated using stable isotopes.

  18. Preliminary study of the uranium potential of the northern part of the Durham Triassic Basin, North Carolina

    SciTech Connect

    Harris, W.B.; Thayer, P.A.

    1981-09-01

    This report presents results of a four-channel spectrometric survey of the northern part of the Durham Triassic basin and adjacent Piedmont, North Carolina. Gamma-ray spectrometric measurements were obtained at 112 localities from 136 different lithologies. The nominal sampling density in the Durham Basin is one site per 2 mi/sup 2/. Surface radiometric surveys reveal no anomalous radioactivity in the northern part of the Durham Basin. Uranium concentrations in Triassic rocks are from 0.6 to 9.7 ppM and average 2.9 ppM. Mudrocks contain from 1.3 to 9.7 ppM, and the average is 4.5 ppM. Sandstones contain from 0.6 to 8.8 ppM, and the average is 2.5 ppM. Fanglomerates contain the lowest concentrations of uranium, from 1.4 to 2.0 ppM, for an average of 1.8 ppM. Uranium/thorium ratios average 0.27 for Triassic rocks and are from 0.04 to 1.85. The mean log uranium/log thorium for Triassic rocks is 0.37. Mudrock has the highest average uranium/thorium ratio (0.32), and the range is 0.09 to 0.66. Sandstones have an average uranium/thorium ratio of 0.26, and the range is 0.04 to 1.85. Fanglomerates have the lowest range uranium/thorium ratio (0.19), and the range is 0.12 to 0.19. On the basis of surface radiometric surveys and geologic studies, it is believed that sedimentary strata in the northern part of the Durham Basin are poor targets for further uranium exploration. This conclusion is based on the lack of favorable characteristics commonly present in fluvial uranium deposits. Among these are: (1) carbonaceous material is absent in Triassic rocks of the northern basin, (2) indicators of a reduzate facies in sandstones are not present, and (3) no tuffaceous beds are associated with sediments in the northern Durham Basin.

  19. Rainfall-runoff modeling and preliminary regional flood characteristics of small rural watersheds in the Arkansas River basin in Colorado

    USGS Publications Warehouse

    Livingston, Russell K.

    1981-01-01

    Both recorded and synthetic rainfall-runoff and annual peak-discharge data for 17 rural watersheds were analyzed to evaluate the magnitude, frequency, and volume of floods in the plains region of the Arkansas River basin in Colorado. Flood-frequency relations from analysis of recorded data were weighted or combined with flood-frequency relations from analysis of synthetic data to provide improved estimates of selected flood characteristics for 15 of these watersheds. The 10-, 25-, 50-, and 100-year peak discharges were regionalized using multiple-regression and station-year methods. Regression relations were developed to determine peak discharge from effective drainage area (standard error of estimate 30 to 50 percent) and flood volume from peak discharge (standard error of estimate 62 percent) for ungaged basins between 0.5 and 15 square miles in size. Using these two flood characteristics, a dimensionless hydrograph method provides synthetic hydrographs very similar in shape to recorded flood hydrographs. (USGS)

  20. Preliminary assessment of climatic change during late Wisconsin time, southern Great Basin and vicinity, Arizona, California, and Nevada

    SciTech Connect

    Spaulding, W.G.; Robinson, S.W.; Paillet, L.

    1984-12-31

    Concentration and relative abundance of plant macrofossils illustrate compositional variations in samples from the Eleana Range-2 packrat midden. Nine macrofossil assemblages spanning 6500 radiocarbon years record local vegetational changes in the southern Great Basin of Nevada during the last one-half of the late Wisconsin glacial age. The vegetation of the Eleana Range-2 site, on a south-facing slope at 1810 meters altitude, was characterized by limber pine and steppe shrubs, from before 17,100 radiocarbon years before present to shortly after 13,200 radiocarbon years before present. Changes toward a more xerophytic plant association at the site began by 16,000 radiocarbon years before present, culminating in a major change to pinyon-juniper woodland between 13,200 and 11,700 radiocarbon years before present. The climatic reconstruction for the late full glacial episode (17,000 to 15,000 radiocarbon years before present) that is proposed to account for limber pine-shrub vegetation in the Eleana Range is characterized by increased winter precipitation, and very little summer rainfall. A major warming trend occurred between about 16,000 and 12,000 radiocarbon years before present and was largely concordant with major dessication of closed lakes in the southern Great Basin. A period of wetter conditions in the southern Great Basin during the latest Wisconsin may have incorporated increased precipitation during both the summer and winter, and lower temperatures during the winter, relative to the present. 93 references, 5 figures, 6 tables.

  1. Equitable water allocation in a heavily committed international catchment area: the case of the Komati Catchment

    NASA Astrophysics Data System (ADS)

    Nkomo, Sakhiwe; van der Zaag, Pieter

    This paper investigates water availability and use in the Komati catchment. The Komati catchment is shared by Swaziland and South Africa and forms part of the Incomati basin, with Mozambique as the third riparian country. In 2002 the three countries reached agreement about how the scarce water should be allocated, based on the principle of equitable and sustainable utilization, as stipulated by the SADC Protocol. The Komati catchment has five main water uses: afforestation, irrigation, the environment, urban/industrial/mining (UIM), and interbasin water transfers (for industrial use). In addition, South Africa and Swaziland have committed themselves to satisfy a certain cross border flow to downstream Mozambique. Frequently, debate has arisen between users and riparian countries on the direction that water resources development has taken in the catchment. Downstream farmers have often complained about interbasin transfers taking place in the upstream portions of the catchment. There has also been animosity about effecting environmental flow releases. A relatively simple, spreadsheet-based water resources model (Waflex) was developed to analyse water availability and use under current and future scenarios. The results were then compared to results obtained from another model that was used in a joint study by Mozambique, South Africa and Swaziland. The Waflex model showed a high degree of consistency with the one used for comparison, especially in terms of trends. It was found that the recent completion of two new dams has improved water supply to irrigation in the two countries. Future water demands will result in appreciable shortages for irrigation and domestic use. The agreed maximum development levels will soon outstrip the ability of the catchments supply. The paper shows that a combination of measures will be required to ensure equitable and sustainable water utilisation in the Komati catchment. These will have to be agreed by the riparian countries. Moreover, over the course of negotiations, important roles will have to be played by catchment management agencies and river boards in Swaziland and South Africa, as well as by the Tripartite Permanent Technical Committee of the three riparian countries.

  2. Soil and water assessment tool model calibration results for different catchment sizes in poland.

    PubMed

    Ostojski, Mieczyslaw S; Niedbala, Jerzy; Orlinska-Wozniak, Paulina; Wilk, Pawel; Gębala, Joanna

    2014-01-01

    The watershed model SWAT (Soil and Water Assessment Tool) can be used to implement the requirements of international agreements that Poland has ratified. Among these requirements are the establishment of catchment-based, rather than administrative-based, management plans and spatial information systems. Furthermore, Polish law requires that management of water resources be based on catchment systems. This article explores the use of the SWAT model in the implementation of catchment-based water management in Poland. Specifically, the impacts of basin size on calibration and on the results of the simulation process were analyzed. SWAT was set up and calibrated for three Polish watersheds of varying sizes: (i) Gąsawka, a small basin (>593.7 km), (ii) Rega, a medium-sized basin (2766.8 km), and (iii) Warta, a large basin (54,500 km) representing about 17.4% of Polish territory. The results indicated that the size of the catchment has an impact on the calibration process and simulation outputs. Several factors influenced by the size of the catchment affected the modeling results. Among these factors are the number of measurement points within the basin and the length of the measuring period and data quality at checkpoints as determined by the position of the measuring station. It was concluded that the SWAT model is a suitable tool for the implementation of catchment-based water management in Poland regardless of watershed size. PMID:25602547

  3. Heterogeneity in catchment properties: a case study of Grey and Buller catchments, New Zealand

    NASA Astrophysics Data System (ADS)

    Shankar, U.; Pearson, C. P.; Nikora, V. I.; Ibbitt, R. P.

    The scaling behaviour of landscape properties, including both morphological and landscape patchiness, is examined using monofractal and multifractal analysis. The study is confined to two neighbouring meso-scale catchments on the west coast of the South Island of New Zealand. The catchments offer a diverse but largely undisturbed landscape with population and development impacts being extremely low. Bulk landscape properties of the catchments (and their sub-basins) are examined and show that scaling of stream networks follow Hack’s empirical rule, with exponents ˜0.6. It is also found that the longitudinal and transverse scaling exponents of stream networks equate to νl ≈0.6 and νw≈ 0.4, indicative of self-affine scaling. Catchment shapes also show self-affine behaviour. Further, scaling of landscape patches show multifractal behaviour and the analysis of these variables yields the characteristic parabolic curves known as multifractal spectra. A novel analytical approach is adopted by using catchments as hydrological cells at various sizes, ranging from first to sixth order, as the unit of measure. This approach is presented as an alternative to the box-counting method as it may be much more representative of hydro-ecological processes at catchment scales. Multifractal spectra are generated for each landscape property and spectral parameters such as the range in α (Holder exponent) values and maximum dimension at α0, (also known as the capacity dimension Dcap), are obtained. Other fractal dimensions (information Dinf and correlation Dcor) are also calculated and compared. The dimensions are connected by the inequality Dcap≥Dinf≥Dcor. Such a relationship strongly suggests that the landscape patches are heterogeneous in nature and that their scaling behaviour can be described as multifractal. The quantitative parameters obtained from the spectra may provide the basis for improved parameterisation of ecological and hydrological models.

  4. Investing in sustainable catchments.

    PubMed

    Everard, Mark

    2004-05-25

    Catchments constitute logical units for management of the water cycle. Patterns of development uninformed by sustainability concerns have degraded catchment integrity and associated ecosystem functions, imposing largely unquantified costs. Ecosystem functions are central to sustainable social and economic progress; their protection or restoration may be the only sustainable form of investment in catchments. Despite growing use of catchment functions in some policy areas, a shortfall in awareness and pragmatic tools limits progress with policies and practical tools to support sustainable development in catchments, perpetuating damaging practices. This paper reviews methods of economic valuation of riverine systems. Valuation of ecosystem functions is revealed as particularly pertinent to sustainable development, as an indicator of the benefits of ecological processes to social and economic progress. A range of practical projects, targeted at restoration of riverine habitat in the UK with the intent of improving both river ecology and the social and economic advantages that flow from it, is also reviewed. Emerging principles and themes are discussed in terms of their potential contribution to policies and practices that promote sustainability. Review of these projects highlights the importance of planning at adequately broad scales--spatial, temporal and disciplinary--to identify integrated solutions, and to maximise community "buy-in" and total benefits. In several cases, economic analyses demonstrate strongly positive benefit-cost ratios stemming from habitat improvement. However, major reform of regulatory and economic instruments is needed to promote sustainable catchment development, since prevalent "perverse" incentives continue to degrade ecosystem functions. Measures to recognise and reward ecosystem service as legitimate outputs from agricultural land use constitute a particular priority. There is a need simultaneously to address both "big picture" structural adjustments and locally-appropriate solutions, from which clear local benefits flow. Pragmatic measures that contribute to systemic outcomes must also be attractive to local decision-makers and land managers, and yield benefits that ensure they are sustained once intervention ceases. Cost need not be a barrier, as current environmentally-damaging subsidies may instead be redirected towards sensitive land use and/or measures to protect biodiversity and ecosystem functioning, particularly where targeted upon habitat of disproportionate importance to functioning of catchments as whole systems. Internalisation of the costs of damage to ecosystem functioning will promote valuation of the natural capital of catchments as a primary resource for social and economic progress. PMID:15081693

  5. Evolution of Lake Chad Basin hydrology during the mid-Holocene: A preliminary approach from lake to climate modelling

    NASA Astrophysics Data System (ADS)

    Sepulchre, Pierre; Schuster, Mathieu; Ramstein, Gilles; Krinnezr, Gerhard; Girard, Jean-Francois; Vignaud, Patrick; Brunet, Michel

    2008-03-01

    During the mid-Holocene (6000 yr Before Present, hereafter yr BP) the Chad Basin was occupied by a large endoreic lake, called Lake Mega-Chad. The existence of this lake at that time seems linked to increased monsoonal moisture supply to the Sahel and the Sahara, which in turn was probably ultimately caused by variations in the orbital forcing and higher temperature gradients between ocean and continent. This study provides a synthesis of several works carried out on the Lake Chad Basin and analyses the results of a simulation of the mid-Holocene climate with an Atmosphere General Circulation Model (LMDZ for Laboratoire de Mtorologie Dynamique, IPSL Paris), with emphasis on the possible conditions leading to the existence of Lake Mega-Chad. The aim is to define the best diagnostics to understand which mechanisms lead to the existence of the large lake. This paper is the first step of an ongoing work that intends to understand the environmental conditions that this part of Africa experienced during the Upper Miocene (ca. 7 Ma BP), an epoch that was contemporaneous with the first known hominids. Indeed, early hominids of Lake Chad Basin, Australopithecus bahrelghazali [ Brunet, M., et al., 1995. The first australopithecine 2500 kilometers west of the Rift-Valley (Chad). Nature, 378(6554): 273-275] and Sahelanthropus tchadensis [Brunet, M., et al., 2002. A new hominid from the Upper Miocene of Chad, central Africa. Nature, 418(6894): 145-151; Brunet, M., et al., 2005. New material of the earliest hominid from the Upper Miocene of Chad. Nature, 434(7034): 752-755] are systematically associated with wet episodes that are documented for 7 Ma BP [Vignaud, P., et al., 2002. Geology and palaeontology of the Upper Miocene Toros-Menalla hominid locality, Chad. Nature, 418(6894): 152-155] and testified by extended lacustrine deposits (diatomites, pelites, various aquatic fauna). Because the mid-Holocene was the last such mega-lake episode, our aim here is to assess the simulated response of Lake Chad to the hydrologic changes caused by 6 kyr BP forcings (orbital variations, albedo, sea surface temperatures) as a test for a future use of the model for studies of the Miocene climate. We show that the induced northward shift of the simulated ITCZ, and the hydrological changes around the lake caused by this shift, are consistent with an increased water balance over the Lake Chad Basin 6000 yr ago. Water supply from the soil (runoff and river inputs) will have to be taken into account in further simulations in order to discuss the timing of the onset, expansion and decay of such a giant water surface in subtropical Africa.

  6. Data-driven catchment classification: application to the PUB problem

    NASA Astrophysics Data System (ADS)

    di Prinzio, M.; Castellarin, A.; Toth, E.

    2011-01-01

    Objective criteria for catchment classification are identified by the scientific community among the key research topics for improving the interpretation and representation of the spatiotemporal variability of streamflow. A promising approach to catchment classification makes use of unsupervised neural networks (Self Organising Maps, SOM's), which organise input data through non-linear techniques depending on the intrinsic similarity of the data themselves. Our study considers ~300 Italian catchments scattered nationwide, for which several descriptors of the streamflow regime and geomorphoclimatic characteristics are available. We qualitatively and quantitatively compare in the context of PUB (Prediction in Ungauged Basins) a reference classification, RC, with four alternative classifications, AC's. RC was identified by using indices of the streamflow regime as input to SOM, whereas AC's were identified on the basis of catchment descriptors that can be derived for ungauged basins. One AC directly adopts the available catchment descriptors as input to SOM. The remaining AC's are identified by applying SOM to two sets of derived variables obtained by applying Principal Component Analysis (PCA, second AC) and Canonical Correlation Analysis (CCA, third and fourth ACs) to the available catchment descriptors. First, we measure the similarity between each AC and RC. Second, we use AC's and RC to regionalize several streamflow indices and we compare AC's with RC in terms of accuracy of streamflow prediction. In particular, we perform an extensive cross-validation to quantify nationwide the accuracy of predictions in ungauged basins of mean annual runoff, mean annual flood, and flood quantiles associated with given exceedance probabilities. Results of the study show that CCA can significantly improve the effectiveness of SOM classifications for the PUB problem.

  7. Modeling relationships between catchment attributes and river water quality in southern catchments of the Caspian Sea.

    PubMed

    Hasani Sangani, Mohammad; Jabbarian Amiri, Bahman; Alizadeh Shabani, Afshin; Sakieh, Yousef; Ashrafi, Sohrab

    2015-04-01

    Increasing land utilization through diverse forms of human activities, such as agriculture, forestry, urban growth, and industrial development, has led to negative impacts on the water quality of rivers. To find out how catchment attributes, such as land use, hydrologic soil groups, and lithology, can affect water quality variables (Ca(2+), Mg(2+), Na(+), Cl(-), HCO 3 (-) , pH, TDS, EC, SAR), a spatio-statistical approach was applied to 23 catchments in southern basins of the Caspian Sea. All input data layers (digital maps of land use, soil, and lithology) were prepared using geographic information system (GIS) and spatial analysis. Relationships between water quality variables and catchment attributes were then examined by Spearman rank correlation tests and multiple linear regression. Stepwise approach-based multiple linear regressions were developed to examine the relationship between catchment attributes and water quality variables. The areas (%) of marl, tuff, or diorite, as well as those of good-quality rangeland and bare land had negative effects on all water quality variables, while those of basalt, forest land cover were found to contribute to improved river water quality. Moreover, lithological variables showed the greatest most potential for predicting the mean concentration values of water quality variables, and noting that measure of EC and TDS have inversely associated with area (%) of urban land use. PMID:25395322

  8. Study of Beijiang catchment flash-flood forecasting model

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Li, J.; Huang, S.; Dong, Y.

    2015-05-01

    Beijiang catchment is a small catchment in southern China locating in the centre of the storm areas of the Pearl River Basin. Flash flooding in Beijiang catchment is a frequently observed disaster that caused direct damages to human beings and their properties. Flood forecasting is the most effective method for mitigating flash floods, the goal of this paper is to develop the flash flood forecasting model for Beijiang catchment. The catchment property data, including DEM, land cover types and soil types, which will be used for model construction and parameter determination, are downloaded from the website freely. Based on the Liuxihe Model, a physically based distributed hydrological model, a model for flash flood forecasting of Beijiang catchment is set up. The model derives the model parameters from the terrain properties, and further optimized with the observed flooding process, which improves the model performance. The model is validated with a few observed floods occurred in recent years, and the results show that the model is reliable and is promising for flash flood forecasting.

  9. Development and Application of a Simple Hydrogeomorphic Model for Headwater Catchments

    EPA Science Inventory

    We developed a catchment model based on a hydrogeomorphic concept that simulates discharge from channel-riparian complexes, zero-order basins (ZOB, basins ZB and FA), and hillslopes. Multitank models simulate ZOB and hillslope hydrological response, while kinematic wave models pr...

  10. Distribution of organic carbon and petroleum source rock potential of Cretaceous and lower Tertiary carbonates, South Florida Basin: preliminary results

    USGS Publications Warehouse

    Palacas, James George

    1978-01-01

    Analyses of 134 core samples from the South Florida Basin show that the carbonates of Comanchean age are relatively richer in average organic carbon (0.41 percent) than those of Coahuilan age (0.28 percent), Gulfian age (0.18 percent) and Paleocene age (0.20 percent). They are also nearly twice as rich as the average world, wide carbonate (average 0.24 percent). The majority of carbonates have organic carbons less than 0.30 percent but the presence of many relatively organic rich beds composed of highly bituminous, argillaceous, highly stylolitic, and algal-bearing limestones and dolomites accounts for the higher percentage of organic carbon in some of the stratigraphic units. Carbonate rocks that contain greater than 0.4 percent organic carbon and that might be considered as possible petroleum sources were noted in almost each subdivision of the Coahuilan and Comanchean Series but particularly the units of Fredericksburg 'B', Trinity 'A', Trinity 'F', and Upper Sunniland. Possible source rocks have been ascribed by others to the Lower Sunniland, but lack of sufficient samples precluded any firm assessment in this initial report. In the shallower section of the basin, organic-rich carbonates containing as much as 3.2 percent organic carbon were observed in the lowermost part of the Gulfian Series and carbonate rocks with oil staining or 'dead' and 'live oil' were noted by others in the uppermost Gulfian and upper Cedar Keys Formation. It is questionable whether these shallower rocks are of sufficient thermal maturity to have generated commercial oil. The South Florida basin is still sparsely drilled and produces only from the Sunniland Limestone at an average depth of 11,500 feet (3500 m). Because the Sunniland contains good reservoir rocks and apparently adequate source rocks, and because the success rate of new oil field discoveries has increased in recent years, the chances of finding additional oil reserves in the Sunniland are promising. Furthermore, the presence of possible source rocks in many of the other stratigraphic units, in particular, the Fredericksburg, should give further impetus to exploring for other productive horizons.

  11. New thermo-mechanical fluid flow modeling of multiscale deformations in the Levant basin: formulation, verification, and preliminary analysis

    NASA Astrophysics Data System (ADS)

    Belferman, Mariana; Katsman, Regina; Agnon, Amotz

    2015-04-01

    The Levant has been repeatedly devastated by numerous earthquakes since prehistorical time, as recorded in historical documents, archaeological ruins, and sedimentary archives. In order to understand the role of the dynamics of the water bodies in triggering the deformations in the Levant basin, a new theoretical thermo-mechanical model is constructed and extended by including a fluid flow component. The latter is modeled on a basis of two-way poroelastic coupling with momentum equation. This coupling is essential to capture the fluid flow evolution induced by dynamic water loading and to resolve porosity changes. All the components of the model, namely elasticity, creep, plasticity, fluid flow, etc., have been extensively verified and presented. Results of the initial sensitivity analysis addressing the relative importance of each process in earthquakes triggering are discussed. The rich archives of pre-instrumental destructive earthquakes will set constraints for future modeling under the present formulation.

  12. D/H Ratios of Terrestrial Lipids from Santa Barbara Basin: A Preliminary Assessment of Paleoclimatic Relevance

    NASA Astrophysics Data System (ADS)

    Sessions, A. L.; Li, C.; Valentine, D. L.; Thiagarajan, N.

    2007-12-01

    Hydrogen isotope (D/H) ratios in sedimentary lipids are increasingly used as a proxy for terrestrial paleoclimate. In arid regions such as southern California, one of the principle problems is finding long-lived lakes to provide the necessary sedimentary archive for this proxy. As a potential alternative, here we explore the D/H record of terrestrial lipids preserved in a marginal marine suboxic basin, Santa Barbara Basin (SBB). Rapid sedimentation, long continuous records, significant terrestrial inputs, and excellent organic preservation all make this site attractive from a geological perspective. But does it record terrestrial climate? To test this, we conducted a survey of lipid D/H ratios in a sediment core collected at the depocenter of SBB, extending back 1200 years before present. Long-chain fatty acids, derived from terrestrial leaf waxes, exhibit virtually no downcore variation in D/H and are uncorrelated with the record of winter Palmer Drought Severity Index (PDSI) in southern California, a proxy for regional precipitation. Long-chain n-alkanes, also derived from leaf waxes, show considerable downcore variability in D/H but are also uncorrelated with PDSI. We believe the temporal variability for n-alkanes may be caused in part by addition of D-enriched fossil hydrocarbons due to increased erosion during wet periods. Regardless, none of these leafwax compounds are a robust paleoclimate proxy in SBB at < 1000-year timescales. In contrast, D/H ratios of n-C22:0 and n-C24:0 fatty acids, commonly attributed to terrestrial aquatic sources, are well correlated with PDSI over this time interval and could serve as a viable paleoclimate proxy. We tentatively attribute the discrepancy between leaf-wax and aquatic biomarkers to a much longer soil residence time for leaf-wax compounds in the watershed, which effectively masks changes over centennial timescales.

  13. Long-term stable water isotope data from large river basins: preliminary analysis of the Global Network of Isotopes in Rivers (GNIR)

    NASA Astrophysics Data System (ADS)

    Halder, Janine; Terzer, Stefan; Wassenaar, Leonard, I.; Araguas-Araguas, Luis; Aggarwal, Pradeep

    2014-05-01

    In 2002 the International Atomic Energy Agency (IAEA) launched an international observation program for the collection and measurement of stable water isotopes and tritium in rivers. The Global network of Isotopes in Rivers (GNIR) now serves as a world-wide repository for contributed riverine isotope data, and expedites public dissemination of isotope data for water research purposes. Currently, the GNIR database contains about 21,000 stable water isotope records from 750 locations in 35 countries, in database format. Basic statistical descriptions are available for 252 observation sites that have isotope records for a minimum of two years. Here, we provide a summary of the GNIR stations established and the data compilations. Because the river locations are from different hydrological settings and climatic zones, the evaluation of the data gives a wide perspective of the global and temporal variations in the isotopic compositions of water in medium-size and large river basins. This synopsis reveals the useful application of stable water isotopes to assess the origin of water sources, mixing with precipitation, glacier and snow melt water, tributaries, the contribution of groundwater to baseflow, as well as, the impact of damming and irrigation return. In addition, the compiled isotope data give insights into temporal and spatial variations in the deuterium-excess and thereby provides independent information to estimate the relevance of evaporation in the water balance of large river basins. This preliminary analysis of the GNIR summarizes moreover, the experience gained from establishing large scale monitoring network stations and stable water isotope data collection within different environments. The GNIR program will be expanded and enhanced into the future with the addition of other biogeochemical isotopes, such as nutrients, particulate organic matter, and sediments. This will enhance gaining further scientific insights and information into water security and quality issues.

  14. Dynamic processes in the mountain catchment

    NASA Astrophysics Data System (ADS)

    Trifonova, Tatiana; Arakelian, Sergei

    2015-04-01

    The process of the river cftchment foundation and the mechanisms being in the basis of its development are not clear at present. Principal phenomena determining the dynamics of formation of the river catchment are under our study in this paper for the case of the mountain basin as an example. The methodology of this monitoring includes the space image recognition and computer data processing of the images for the Maliy Caucasus Mountains. Mountain river catchment formation on the slope of the ridge can be considered as a self-organizing staged process of its evolution passing through several non-equilibrium but steady-state conditions. We consider a system of tributaries in the mountain river catchment as a system of cracks, which are formed on the slope of the mountain massif. In other words, the formation of river networks should be the result of development of several processes, among of which the mechanisms of crack development should play a dominant role. The principal results, discussed in the present report, can be formulated as follow. (1) The mountain catchment (litho-watershed) formation takes place under conditions of the confined states of a mountain massif: on the one hand it is bounded by the surface of the slope; but on the other hand, - by a primary cracks density occurrence (as a spatial distribution 3D-crack net). (2) The development in time of the river catchment takes place by several stages. Each stage specifies a definite energetic state of the system in the mountain massif. (3) The overhead river streams arise not only due to surface water, but and namely due to rising of water from underground water horizons over the watercourse cracks penetrating deeply into the underground. (4) The 3D-river catchment structure results in concept in behavior of the unit as an open nonlinear dynamic system with a spatially distributed feedback. The energetic (endogen) processes of formation, rising and bifurcation for cracks are the consequence of relaxation of tension accumulating into of the mountain materials, and result in specific geometrical image of the river stream system. Exogenic processes of depression have a secondary meaning and take part in organization of the relief picture inside of the basin. Geological peculiarities, concrete physic-chemical properties of the mountain massive and different external factors are overlapped on indicated primary processes, and such complicated picture establishes the morphology of the catchment in general. The conclusion is, the mountain river catchment is the vertical geosystem with the predominantly descending fluxes of substances . Its development in time results in interrelated processes of mountainous massif destruction and, as to direction of the river's channel fracturing growth, the process is going up over the slope. The water balance in such a 3D -system should take into account both surface water and groundwater.

  15. Preliminary Modelling of the Effect of Impurity in CO2 Streams on the Storage Capacity and the Plume Migration in Pohang Basin, Korea

    NASA Astrophysics Data System (ADS)

    Park, Yongchan; Choi, Byoungyoung; Shinn, Youngjae

    2015-04-01

    Captured CO2 streams contain various levels of impurities which vary depending on the combustion technology and CO2 sources such as a power plant and iron and steel production processes. Common impurities or contaminants are non-condensable gases like nitrogen, oxygen and hydrogen, and are also air pollutants like sulphur and nitrogen oxides. Specifically for geological storage, the non-condensable gases in CO2 streams are not favourable because they can decrease density of the injected CO2 stream and can affect buoyancy of the plume. However, separation of these impurities to obtain the CO2 purity higher than 99% would greatly increase the cost of capture. In 2010, the Korean Government announced a national framework to develop CCS, with the aim of developing two large scale integrated CCS projects by 2020. In order to achieve this goal, a small scale injection project into Pohang basin near shoreline has begun which is seeking the connection with a capture project, especially at a steel company. Any onshore sites that are suitable for the geological storage are not identified by this time so we turned to the shallow offshore Pohang basin where is close to a large-scale CO2 source. Currently, detailed site surveys are being undertaken and the collected data were used to establish a geological model of the basin. In this study, we performed preliminary modelling study on the effect of impurities on the geological storage using the geological model. Using a potential compositions of impurities in CO2 streams from the steel company, we firstly calculated density and viscosity of CO2 streams as a function of various pressure and temperature conditions with CMG-WINPROP and then investigated the effect of the non-condensable gases on storage capacity, injectivity and plume migrations with CMG-GEM. Further simulations to evaluate the areal and vertical sweep efficiencies by impurities were perform in a 2D vertical cross section as well as in a 3D simulation grid. Also, pressure increases caused by the impurities and the partitioning between CO2 and other non-condensable gases were explored. In addition, the possibility of using these contaminants as a tracer were examined.

  16. Creating a catchment perspective for river restoration

    NASA Astrophysics Data System (ADS)

    Benda, L.; Miller, D.; Barqun, J.

    2011-03-01

    One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we coupled general principles of hydro-geomorphic processes with computer tools to characterize the fluvial landscape. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to topography, valley morphology, river network structure, and fan and terrace landforms. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  17. Preliminary assessment of climatic change during Late Wisconsin time, southern Great Basin and vicinity, Arizona, California, and Nevada

    USGS Publications Warehouse

    Spaulding, W.G.; Robinson, S.W.; Paillet, F.L.

    1984-01-01

    Nine plant macrofossil assemblages from the Eleana Range-2 packrat (Neotoma sp.) midden span 6,500 radiocarbon years and record local vegetational changes in the southern Great Basin of Nevada during the last one-half of the Late Wisconsin glacial age. Climatic reconstructions were developed to account for these changes. During the late full glacial episode (17,000 to 15,000 radiocarbon years before the present), winter precipitation was about 70% greater than present winter precipitation, and summer rainfall was minimal. Average annual precipitation probably exceeded present annual precipitation by less than 40%. Annual temperatures were about 6 to 7 C lower than the present average, and evidence exists for winter temperatures much lower than those of the present. A major warming trend occurred between about 16,000 and 12,000 radiocarbon years before present. By the latest Wisconsin (12 ,000 to 10,000 radiocarbon years before present), annual temperatures were within 2 C of temperatures of the present. During the latest Wisconsin, precipitation was greater during the winter, relative to the present. The climate of this pluvial event was much different from that of the preceding full glacial episode and is consistent with current models of astronomically induced climatic changes. (USGS)

  18. Preliminary paleogeographic reconstruction of the Illinois basin during deposition of the Mississippian Aux Vases Formation: Implications for hydrocarbon recovery

    SciTech Connect

    Cole, R.D. )

    1991-03-01

    Extensive outcrop investigation and selective subsurface study allow definition of Illinois basin paleogeography during deposition of the Mississippian (Valmeyeran-Meramecian) Aux Vases Formation. The results incorporate an integrated approach utilizing field observations and petrographic analysis, wireline logs, subsurface maps, and cores. The Aux Vases Formation depositional system has been determined to be composed of subtidal to intertidal facies. Depositional facies in outcrop are based on rock body geometries, sedimentary structure assemblages, paleocurrent analysis, paleontology of body and trace fossils, facies relationships, and petrography. Depositional facies determined from subsurface data are based on correlation of lithologic interpretations from wireline logs, sand body geometries form isopach maps, and petrography. Specific depositional facies observed in outcrop and core and inferred from wireline logs and isopach maps are offshore bars and tidal channel complexes, extensive subtidal to lower intertidal, ripple-laminated, fine-grained quartzose sandstone. Carbonate facies occur as subtidal grainstones at or near the base of a sequence, or as high energy deposits which have been tidally reworked. This depositional system produces reservoir heterogeneities that complicate efficient hydrocarbon recovery. This diverse facies architecture is modified by tectonic and diagenetic overprinting, further segregating potential producing zones. To significantly improve recovery efficiency, predictions regarding compartmentalization can be used prior to designing a drilling program, an infill drilling program, or an application of enhanced recovery techniques.

  19. A preliminary sub-basin scale evaluation framework of site suitability for onshore aquifer-based CO2 storage in China

    SciTech Connect

    Wei, Ning; Li, Xiaochun; Wang, Ying; Dahowski, Robert T.; Davidson, Casie L.; Bromhal, Grant

    2013-01-30

    Development of a reliable, broadly applicable framework for the identification and suitability evaluation of potential CO2 storage sites is essential before large scale deployment of carbon dioxide capture and geological storage (CCS) can commence. In this study, a sub-basin scale evaluation framework was developed to assess the suitability of potential onshore deep saline aquifers for CO2 storage in China. The methodology, developed in consultation with experts from the academia and the petroleum industry in China, is based on a multi-criteria analysis (MCA) framework that considers four objectives: (1) storage optimization, in terms of storage capacity and injectivity; (2) risk minimization and storage security; (3) environmental restrictions regarding surface and subsurface use; and (4) economic considerations. The framework is designed to provide insights into both the suitability of potential aquifer storage sites as well as the priority for early deployment of CCS with existing CO2 sources. Preliminary application of the framework, conducted using GIS-based evaluation tools revealed that 18% of onshore aquifer sites with a combined CO2 storage capacity of 746 gigatons are considered to exhibit very high suitability, and 11% of onshore aquifer sites with a total capacity of 290 gigatons exhibit very high priority opportunities for implementation. These onshore aquifer sites may provide promising opportunities for early large-scale CCS deployment and contribute to CO2 mitigation in China for many decades.

  20. A preliminary sub-basin scale evaluation framework of site suitability for onshore aquifer-based CO{sub 2} storage in China

    SciTech Connect

    Wei, Ning; Li, Xiaochun; Wang, Ying; Dahowski, Robert T.; Davidson, Casie L.; Bromhal Grant S.

    2013-01-01

    Development of a reliable, broadly applicable framework for the identification and suitability evaluation of potential CO{sub 2} storage sites is essential before large-scale deployment of carbon dioxide capture and geological storage (CCS) can commence. In this study, a sub-basin scale evaluation framework was developed to assess the suitability of potential onshore deep saline aquifers for CO{sub 2} storage in China. The methodology, developed in consultation with experts from the academia and the petroleum industry in China, is based on a multi-criteria analysis (MCA) framework that considers four objectives: (1) storage optimization, in terms of storage capacity and injectivity; (2) risk minimization and storage security; (3) environmental restrictions regarding surface and subsurface use; and (4) economic considerations. The framework is designed to provide insights into both the suitability of potential aquifer storage sites as well as the priority for early deployment of CCS with existing CO{sub 2} sources. Preliminary application of the framework, conducted using GIS-based evaluation tools revealed that 18% of onshore aquifer sites with a combined CO{sub 2} storage capacity of 746 gigatons are considered to exhibit very high suitability, and 11% of onshore aquifer sites with a total capacity of 290 gigatons exhibit very high priority opportunities for implementation. These onshore aquifer sites may provide promising opportunities for early large-scale CCS deployment and contribute to CO{sub 2} mitigation in China for many decades.

  1. A methodological comparison of catchment storages in mountainous catchments

    NASA Astrophysics Data System (ADS)

    Weiler, Markus; Staudinger, Maria; Stlzle, Michael; Seeger, Stefan; Seibert, Jan; Stahl, Kerstin

    2015-04-01

    One of the most important functions of catchments is the temporary storage of water, which directly influences runoff dynamics, rainfall-runoff transformation, partitioning of evaporation and runoff fluxes, and accessibility of water to plants. Generally, a large catchment storage is considered beneficial and in particular increases the transit times and hence the buffer functioning related to water quality. Many different methods have been developed to assess catchment storage, however, there are hardly any direct comparisons of several of these methods. One challenge is the definition of water storage, while some methods allow estimation of the entire water storage in a catchment, other methods quantify only the dynamic storage. In addition, most studies focused more on lowland catchments with rain-dominated runoff regimes and observed groundwater fluctuations. Furthermore, these studies often focus on one or two catchments, but do not consider the influence of different climates on the relevance of water storage in the catchment. We applied a range of different methods to assess catchment storage characteristics in 18 catchments in the Swiss Alps, ranging from 500 to 2000m of mean elevation and hence from rainfall- to snowmelt dominated runoff regimes. The first method use only discharge information during recession periods and with varying approaches to extract discharge and storage changes between high flow and low flow, the dynamic catchment storage can be derived. In the next methods the conceptual hydrological model HBV is calibrated to the runoff dynamics and the dynamic and total catchment storages of the different compartments are being evaluated. The last methods are based on stable water isotope data analysis. We use the model TRANSEP to derive the dynamic storage as well as the total water storage of the catchment based on the transit times using several years of fortnightly isotope data in streamflow. The results show that the derived catchment storage characteristics are strongly dependent on the chosen method. However, the overall ranking of the catchments among the methods is quite similar, despite the derived catchment storage of one catchment may differ by one to two orders of magnitude. Surprisingly, the high elevation catchments generally show a much larger storage than most of the low elevation catchments. To investigate this surprising result further, we analyzed the effect of climate on the derived catchment storage in more detail, since an additional snow storage with the resulting melt period in spring may produce an large dynamic storage due to the concentrated input of water. We both used subsamples of discharge to divide the storage in snow or rain triggered storage and changed the climate input either to a rainfall or snowmelt dominated climate and compared the storage among the catchments based on a similar climate signal. We finally develop a framework for assessing and comparing catchment storages among catchments in different climates, geologies and with different physiographic characteristics. These analyses also provided more insights into the larger storage in mountainous catchments and its importance to catchments functions.

  2. Hillslope versus riparian zone runoff contributions in headwater catchments: A multi-watershed comparison

    NASA Astrophysics Data System (ADS)

    McGlynn, B. L.; McGlynn, B. L.; McDonnell, J. J.; Hooper, R. P.; Shanley, J. B.; Hjerdt, K. N.; Hjerdt, K. N.

    2001-12-01

    It is often assumed that hillslope and riparian areas constitute the two most important and identifiable landscape units contributing to catchment runoff in upland humid catchments. Nevertheless, the relative amount and timing of hillslope versus riparian contributions to stormflow are poorly understood across different watersheds. We quantified the contributions of hillslopes and riparian zones to stormflow using physical, chemical, and isotopic techniques across 3 diverse ({ ~}15 ha) headwater catchments: a highly responsive steep wet watershed (Maimai, New Zealand), a moderately steep snowmelt dominated watershed (Sleepers, River, VT), and at a highly seasonal relatively low relief watershed (Panola Mt., Georgia). We monitored catchment runoff, internal hydrological response, and isotopic and solute dynamics for discrete riparian and hillslope zones within each catchment. Monitored catchment positions, including hillslope trenches at Maimai and Panola, were used to characterize directly, the hydrologic response and source water signatures for hillslope zones and riparian zones. We also examined the spatial and temporal source components of catchment stormflow using 3-component mass balance hydrograph separation techniques. At Maimai, NZ we found that hillslope runoff comprised 47-55% of total runoff during a 70 mm event. Despite the large amount of subsurface hillslope runoff in total catchment stormflow, riparian and channel zones accounted for 28% out of 29% of the total new water measured catchment runoff. Riparian water dominated the storm hydrograph composition early in the event, although hillslope water reached the catchment outlet soon after hillslope water tables were developed. Preliminary results for Sleepers River, VT and Panola Mountain, GA indicate that the timing and relative proportion of hillslope water in catchment runoff is later and smaller than at Maimai. Our multi-catchment comparison suggests that the ratio of the riparian reservoir to the hillslope reservoir/stormflow flux partially controls the relative contributions of hillslope and riparian zones to catchment runoff and solute dynamics.

  3. Catchment controls on solute export

    NASA Astrophysics Data System (ADS)

    Musolff, Andreas; Schmidt, Christian; Selle, Benny; Fleckenstein, Jan H.

    2015-12-01

    Dynamics of solute export from catchments can be classified in terms of chemostatic and chemodynamic export regimes by an analysis of concentration-discharge relationships. Previous studies hypothesized that distinct export regimes emerge from the presence of solute mass stores within the catchment and their connectivity to the stream. However, so far a direct link of solute export to identifiable catchment characteristics is missing. Here we investigate long-term time series of stream water quality and quantity of nine neighboring catchments in Central Germany ranging from relatively pristine mountain catchments to agriculturally dominated lowland catchments, spanning large gradients in land use, geology, and climatic conditions. Given the strong collinearity of catchment characteristics we used partial least square regression analysis to quantify the predictive power of these characteristics for median concentrations and the metrics of export regime. We can show that median concentrations and metrics of the export regimes of major ions and nutrients can indeed be inferred from catchment characteristics. Strongest predictors for median concentrations were the share of arable land, discharge per area, runoff coefficient and available water capacity in the root zone of the catchments. The available water capacity in the root zone, the share of arable land being artificially drained and the topographic gradient were found to be the most relevant predictors for the metrics of export regime. These catchment characteristics can represent the size of solute mass store such as the fraction of arable land being a measure for the store of nitrate. On the other hand, catchment characteristics can be a measure for the connectivity of these solute stores to the stream such as the fraction of tile drained land in the catchments. This study demonstrates the potential of data-driven, top down analyses using simple metrics to classify and better understand dominant controls of solute export from catchments.

  4. Geochemical signature and properties of sediment sources and alluvial sediments within the Lago Paranoá catchment, Brasilia DF: a study on anthropogenic introduced chemical elements in an urban river basin.

    PubMed

    Franz, C; Makeschin, F; Weiß, H; Lorz, C

    2013-05-01

    One of the largest urban agglomerations in Brazil is the capital Brasilia and its surrounding area. Due to fast urban sprawl and accelerated land use changes, available water supplies are near their limits. The water supply depends largely on surface water collected in reservoirs. There are increasing concerns regarding water shortages due to sediment aggradations, and of water quality due to geochemical modification of sediments from human activities. The concentration of 18 chemical elements and five sediment properties was analyzed from different potential land-based sediment sources and deposited alluvial sediment within the Lago Paranoà catchment. The goal of this study was to assess the distribution of chemical elements and geochemical/physical properties of potential sediment sources in the Lago Paranoá catchment. Principal component analysis and hierarchical cluster analysis were used to investigate the influence of different land use types on the geochemistry of sediments. Geochemical fingerprints of anthropogenic activities were developed based on the results of the cluster analysis grouping. The anthropogenic input of land use specific geochemical elements was examined and quantified by the calculation of enrichment factors using the local geological background as reference. Through comparison of the geochemical signature of potential sediment sources and alluvial sediments of the Lago Paranoá and sub-catchments, the relative contribution of land use specific sediment sources to the sediment deposition of the main water reservoir were estimated. The existing findings suggest a strong relationship between land use and quantifiable features of sediment geochemistry and indicate that urban land use had the greatest responsibility for recent silting in the Lago Paranoá. This assessment helps to characterize the role of human activities in mixed-used watersheds on sediment properties, and provides essential information to guide management responses towards more effective source-reduction strategies. PMID:23542435

  5. The anthropic catchment-ecosystem concept: an Irish example

    SciTech Connect

    Phillips-Howard, K.D.

    1985-06-01

    The catchment-ecosystem concept is adapted to investigate the nutrient-budget of the highly-modified Colebrooke drainage basin in Northern Ireland. Anthropogenic inputs, mainly manures and fertilizers, account for 86% of the nitrogen and 96% of the phosphorus added to the catchment. These inputs greatly exceed the streamflow outputs, thereby indicating that the flow of nutrients is dominated by agriculture. This is explained by the transformation of traditional mixed farming into more intensive livestock production and is linked to policies encouraging increased agricultural production, amalgamation of farms, afforestation, rural depopulation, and urbanization. Substantial increases in the N and P output of the catchment and further eutrophication of the recipient lake, Lough Erne, are predicted without the implementation of policies to reduce agricultural nutrient losses.

  6. Catchment isotope ecohydrology: Unraveling the combined influences of vegetation and topography on runoff generation in forested headwater catchments

    NASA Astrophysics Data System (ADS)

    Singh, N. K.; Rice, J. S.; Nippgen, F.; Jencso, K. G.; McGlynn, B. L.; Emanuel, R. E.

    2011-12-01

    The combined influence of topography and vegetation on runoff generation and streamflow in headwater catchments remains unclear. We focus on the complex inter-relationships among catchment runoff generation factors using 2H and 18O as tracers of runoff sources. We investigated two pairs of catchments at the Coweeta Hydrologic Laboratory (CHL) in the southern Appalachian Mountains (Otto, NC). Our study site comprised four small (approximately 10 ha) catchments, two of which contained broadleaf deciduous vegetation and two of which contained evergreen coniferous vegetation. During the 2011 growing season, we collected spatial synoptic samples along streams at 25 m intervals, from shallow riparian and hillslope wells, deep monitoring wells, and at rain gauges in or near all four watersheds on a monthly basis (samples were analyzed for 2H and 18O using cavity ring-down spectroscopy). Preliminary data from these four catchments showed high spatial and temporal variability in 2H and 18O in stream and well waters during the 2011 growing season. Some of this variability was attributable to natural variation in precipitation isotopes, whereas other variability showed evidence of mixing among different water sources and potential isotopic fractionation. One result of this mixing and fractionation was frequent enrichment of 2H and 18O in stream water moving from the channel head to the outlet in three out of four studied catchments. In these catchments, ?2H and ?18O of stream water at the base of hillslopes resembled both riparian well water and hillslope well water, suggesting distinct contributions of hillslopes to runoff during certain time periods. We seek to further explore and attribute the observed synoptic patterns and their periodic organization in space and time using remotely sensed topography and vegetation data to improve understanding of headwater catchment ecohydrology.

  7. New Techniques for Hydrothermal Exploration: In Situ Chemical Sensors on AUVs - Preliminary Results From the Lau Basin

    NASA Astrophysics Data System (ADS)

    German, C. R.; Connelly, D. P.; Prien, R. D.; Yoerger, D.; Jakuba, M.; Bradley, A.; Shank, T. J.; Edmonds, H. N.; Langmuir, C. H.

    2004-12-01

    Less than one quarter of the global ridge-crest has yet received even cursory investigation for the presence or absence of hydrothermal activity. To improve exploration efficiency, particularly at high latitudes, new methodologies independent of tethered vehicles are required. To that end, we have begun the use of in situ chemical sensors allied to the increasing capabilities of autonomous underwater vehicles. Here, we present first results from our most recent efforts aboard the second R2K cruise to the Lau Basin (C.Langmuir, PI; Autumn 2004) to (a) map non-buoyant hydrothermal plumes, (b) intercept buoyant hydrothermal plumes and (c) locate and image novel hydrothermal fields on the seafloor. The AUV used for this work is ABE and the sensors deployed are direct extensions of the in situ Fe/Mn sensor deployed previously on SOC's AUTOSUB to investigate seasonally-reducing waters in Loch Etive, NW Scotland. Each in situ instrument comprises an electronics package that contains a tattletale control system with a flash memory card for on-board logging and a chemical manifold, consisting of a series of valves, pumps and a colorimetric cell. Analysis of iron is enabled by the determination of the coloured complex formed between iron II and ferrozine, manganese uses the colour change of PAN in the presence of reduced manganese. The system includes capacity for switching between sample, blank and two on-board samples for "in flight" calibrations with blanks and standards held in medical bags, outside of the pressure-balanced manifold, to attain in situ water-column temperatures. An in-line filter prevents large particle clogging and detection limits for both iron II and manganese II are ca.2nM.

  8. Atmospheric methane flux from coals - preliminary investigation of coal mines and geologic structures in the Black Warrior Basin, Alabama

    SciTech Connect

    Clayton, J.L.; Leventhal, J.S.; Rice, D.D. ); Pashin, J.C. ); Mosher, B.; Czepiel, P. )

    1993-01-01

    Methane is an important greenhouse gas whose concentration in the atmosphere is increasing. Although this increase in atmospheric methane is correlative with growth in human population and activities, the exact causes for the increase are not fully understood. Because of increasing energy demand, particularly in developing countries where population is increasing, coal production is likely to increase over the next few decades and this could further increase the flux of atmospheric methane. In addition, no data are currently available on methane flux from coalbeds as a result of natural processes such as leakage at outcrops, or along faults and fractures that could provide avenues for methane migration upward from coal at depth. To better understand the global methane cycle and the role of fossil fuels in methane emissions, field measurements of methane emissions are needed from coalbeds, from areas of active mining, from coalbed gas production, and from undisturbed coals. In this paper, we report results of field measurements of CH[sub 4] emissions from surface and underground mines, fault zones, and coreholes in the Black Warrior Basin, Alabama. Ventilation of underground mines in Mary Lee group coals (of economic usage) gave the highest methane emissions rates - about 71,480,000 m[sup 3]/yr (2.5 Bcf or billion cubic feet) from one ventilation shaft. In contrast, very low emissions occurred from active or abandoned coreholes and from Brookwood group coals (of economic usage) exposed by surface mining (about 81 m[sup 3]/yr (2.9 Mcf or thousand cubic feet)). Methane flux of as much as about 500 m[sup 3]/yr occurs from a small section of a normal fault and associated joints exposed at Bankhead Lock and Dam. The carbon isotopic composition of CH[sub 4] collected at the Bankhead Fault ([delta][sup 13]C -49.3 permil) indicates a coalbed origin. 50 refs., 15 figs., 4 tabs.

  9. Assesing Hydrophysical/Enivornmenal impacts by Dams in the Amazon (fluvial) Basin

    NASA Astrophysics Data System (ADS)

    Wight, C.; Latrubesse, E. M.

    2014-12-01

    Growing demands from human activities are increasing the pressure and impacts on the Amazon River basin. Covering almost 40% of South America, the Amazon River basin's health is of global importance. With tributaries in 6 different countries, the anthropogenic impacts on this large system are complex and hard to synthesize. However to better understand large system responses to human impacts such an analysis is called for. Our objective is to organize a rigorous analysis of the potential hydro-physical impacts of dams on the major sub-basins of the Amazon. We are incorporating existing data of sediment fluxes, deforestation and land-use land-change to include the entire extent of the basin as defined by the fluvial unit. In addition, we will be analyzing the spatial distributions of dams (planned, under construction, and constructed) within each sub-basin. Our preliminary results have used statistical analysis and remote sensing to calculate the extent of deforestation on fluvial regimes of the legal Amazon and concentrated to identify the potential disruptions of sediment fluxes. Combining the spatial distributions of dam sites, and deforestation per sub-basin we will develop a system to interpret land-use and land-change per catchment. This in turn will allow us to better predict changes in the fluvial regimes and allow for comparisons of vulnerability.

  10. Nutrient loads exported from managed catchments reveal emergent biogeochemical stationarity

    NASA Astrophysics Data System (ADS)

    Basu, Nandita B.; Destouni, Georgia; Jawitz, James W.; Thompson, Sally E.; Loukinova, Natalia V.; Darracq, Amélie; Zanardo, Stefano; Yaeger, Mary; Sivapalan, Murugesu; Rinaldo, Andrea; Rao, P. Suresh C.

    2010-12-01

    Complexity of heterogeneous catchments poses challenges in predicting biogeochemical responses to human alterations and stochastic hydro-climatic drivers. Human interferences and climate change may have contributed to the demise of hydrologic stationarity, but our synthesis of a large body of observational data suggests that anthropogenic impacts have also resulted in the emergence of effective biogeochemical stationarity in managed catchments. Long-term monitoring data from the Mississippi-Atchafalaya River Basin (MARB) and the Baltic Sea Drainage Basin (BSDB) reveal that inter-annual variations in loads (LT) for total-N (TN) and total-P (TP), exported from a catchment are dominantly controlled by discharge (QT) leading inevitably to temporal invariance of the annual, flow-weighted concentration, $\\overline{Cf = (LT/QT). Emergence of this consistent pattern across diverse managed catchments is attributed to the anthropogenic legacy of accumulated nutrient sources generating memory, similar to ubiquitously present sources for geogenic constituents that also exhibit a linear LT-QT relationship. These responses are characteristic of transport-limited systems. In contrast, in the absence of legacy sources in less-managed catchments, $\\overline{Cf values were highly variable and supply limited. We offer a theoretical explanation for the observed patterns at the event scale, and extend it to consider the stochastic nature of rainfall/flow patterns at annual scales. Our analysis suggests that: (1) expected inter-annual variations in LT can be robustly predicted given discharge variations arising from hydro-climatic or anthropogenic forcing, and (2) water-quality problems in receiving inland and coastal waters would persist until the accumulated storages of nutrients have been substantially depleted. The finding has notable implications on catchment management to mitigate adverse water-quality impacts, and on acceleration of global biogeochemical cycles.

  11. Analyzing the effect of urbanization on flood characteristics at catchment levels

    NASA Astrophysics Data System (ADS)

    Chen, X.; Tian, C.; Meng, X.; Xu, Q.; Cui, G.; Zhang, Q.; Xiang, L.

    2015-06-01

    It is increasingly recognized that the land-use change, especially urbanization has influenced hydrological attributes intensely. Flood characteristics variation could likewise increase flood risks and pose higher demand on water management. The paper aims to evaluate temporal and spatial processes of urbanization affecting flood events at catchment level. The study sites were Xiaoqinhe catchment and its sub-catchments, a part of lower Yellow river basin in northern China. Historic cities Jinan and Zibo in the area have experienced dramatic urban expansion in recent decades, about 5% growth of urban build-up area annually from 1990s to 2010s, and also pressed alarm for increasing flood disasters. In the paper, a HEC-HMS model was set up to simulate flood processes for different land-use scenarios. The possible effects of urbanization on flood characteristics were checked in study catchment and its sub-catchments.

  12. Effects Of Land Cover Change On The Hydrologic Regime Of Kabompo River Basin, Zambia

    NASA Astrophysics Data System (ADS)

    Kampata, J. M.; Rientjes, T. H. M.; Timmermans, J.

    2013-12-01

    Over the past decades, the Kabompo River Basin in Zambia is affected by deforestation and land degradation as a consequence of intensified agriculture and mining. Changes presumably have affected the hydrological catchment behaviour and related seasonal flow regimes. Impact assessments are unknown for the basin. In this study multi-decadal time series of rainfall and stream flow were evaluated by trend analysis, change point detection methods and analysis on high and low flow exceedance probabilities. Results are combined with satellite based land cover observations for 1984, 1994, 2001 and 2009. Unsupervised classification of the Landsat images indicate pronounced land cover changes. Preliminary results of this study show that i) precipitation time series are not directly affected by climate change and ii) changes in stream flow can be linked to changes in land cover.

  13. Changes in runoff generation due to conversion of catchment vegetation

    NASA Astrophysics Data System (ADS)

    Vilhar, Urša; Kestnar, Klemen; Šraj, Mojca

    2015-04-01

    In Central Europe, many pure Norway spruce stands, established on primary beech sites, were converted into mixed stands over the last 60 years. The conversion of forest management from Norway spruce monocultures into mixed deciduous-coniferous forests changed the forest structure dramatically. This changes could influence the hydrological processes on the catchment scale, associated with changes in runoff generation. In this study, the effect of forest management on the runoff in mixed deciduous-coniferous stands on Pohorje mountains in NE Slovenia were investigated. Two small forested experimental catchments of Oplotnica River on Pohorje were compared with similar size and shape but different share of Norway spruce Picea abies (L. Karst) and European beech Fagus sylvatica (L.). Measured stream flows, throughfall, stemflow and the mixture of forests were compared in the period 2008 till 2013 for both catchments. Hydrological models in the HEC-HMS program were built for both catchmenta, calibrated and validated using measured data. Precipitation losses were estimated by the Soil Conservation Service (SCS) method, while precipitation was converted into surface runoff using the SCS synthetic unit hydrograph procedure. The measured seasonal throughfall and stream flow was lower in the catchment with higher share of spruce in the mixed spruce-beech forest. Modeled precipitation losses in the river basins were 92% and 95% of total precipitation, respectively. The results indicate higher interception, infiltration and accumulation of precipitation in the catchment with higher share of spruce in the mixed spruce-beech forest. Forest management practices should aim towards decreased surface runoff in alpine catchments. Therefore implementation of hydrology-oriented sylvicultural measures via a more accurate prediction of the impacts of tree species conversion on runoff generation in this type of alpine catchments is discussed.

  14. Rainfall-runoff modelling approach for ungauged catchments: A case study of Nzhelele River sub-quaternary catchment

    NASA Astrophysics Data System (ADS)

    Makungo, R.; Odiyo, J. O.; Ndiritu, J. G.; Mwaka, B.

    This paper presents a rainfall-runoff (RR) modelling method aimed at generating natural streamflow from the modified nearest neighbour regionalization approach applied to two ungauged sub-quaternary catchments (SQCs) nested within an ungauged quaternary catchment. It differs from the commonly used nearest neighbour regionalization approach involving a gauged quaternary catchment and an ungauged quaternary catchment. This approach ensures improvement in homogeneity of the estimated hydrological parameters. Lack of gauged streamflows hampers water resources planning and management, and water resources systems operation including allocations for environmental flows. The method has been applied in the Tshiluvhadi and the Nzhelele Rivers SQCs in quaternary catchment A80A of the Nzhelele River Catchment in the Limpopo River Basin. The modelling approach involved computing inflow hydrograph from a water balance model for Mutshedzi Dam. The hydrograph was then used in the calibration and verification of the RR model for the Tshiluvhadi River SQC using the Mike 11 NAM and Australian Water Balance Model (AWBM) in order to determine the model with better performance. The performance of each of the two models assessed by using the Root Mean Square Error, Nash Sutcliffe coefficient of efficiency, the correlation coefficient, % Bias and the overall water balance error was good and comparable. The two models, however, tended to underestimate the high flows. The models were used to simulate runoff hydrographs for the ungauged Nzhelele River SQC using model parameters obtained from the Tshiluvhadi SQC RR modelling. The streamflow hydrographs for the Nzhelele River SQC simulated from both the models are comparable and show behaviour similar to that reported in earlier studies. They also correlate well with the areal rainfall for the Nzhelele River SQC. The modelling results show that the approach is reasonably good and therefore can be used in predicting runoff in ungauged catchments. The simulated runoff hydrographs can be used in water resources planning and management, and water resources systems operation.

  15. Modeling of matters removal from swampy catchment

    NASA Astrophysics Data System (ADS)

    Inishev, N. G.; Inisheva, L. I.

    2010-05-01

    This work shows the results of fixed study of geochemical conditions in the system of landscape oligotrophic profile at Vasyugan mire spurs, and also we make an approach to processes modelling of compounds removal from swampy catchment. During investigation of symbolic model of chemical matters removal from the surface of a catchment basin and their movement along the channel network it was taken into account that removal of chemical elements during the period of spring flood and rain high waters occur mainly with overland flow. During calculation of dissolved matters movement the following admissions take place: 1. The problem is solved at one-dimension set-up. Concentration of investigated components is taken as averaged one along the flow cross section or effective area of slope cross-section for overland runoff, i.e. it changes only lengthways and in time. 2. It is considered that dissolved matters spread due to movement of water and together with its particles. 3. Processes of water self-clarification are not considered. The model is calculated on the basis of discharge of the investigated ingredient, i.e. matter mass moving through the given flow cross-section into time unit. This is the peculiarity of the model. Matter removal together with water flow is determined if necessary. Everyday impurity consumptions and its concentration can be estimated at the outlet at the moment of time according to convolution integral. Estimation of overland runoff and water inflow into the channel network is based on the mathematic model of outflow formation from peatland areas which considers basic processes carrying out at catchment and basin channel network. Stored moisture estimation of snow cover is taken according to snow survey data before snow melting. Everyday water supply to the surface of water collection was determined according to the results of snow melt intensity estimation by the methods of temperature coefficient and water yield from snow (A.G. Kovzel). All the estimations were made taking into account layering unevenness of snow cover in deferent landscapes. Stored water distribution in the limits of every landscape was approximated by the curve of gamma distribution with parameters which are the results of snow survey. Everyday basin water yield was determined as difference between excesses of water coming above usage for filling of its water retaining tank. The size of the water retaining tank before start of snow melting depends on the basin wetting in the previous autumn. Autumn river flow is taken as a degree of water retaining tank filling before the snow melt. It is supposed that there is a process of water accumulation at slopes. Between theses water supplies and overland runoffs there is a nonlinear link. Temporary melt water detention, which comes from mire in swamp forest, is considered. Estimations are made individually for field, forest and swamp parts of the basin of the river Kljuch. Estimation of HA removal from the surface of catchment of the river Kljuch is taken as an example of model application. The results reveal possibilities of the given approach to modeling of dissolved matters removal from the swampy area. Acknowledgements: This research was supported by RFFR (No.No. 09-05-00235, 09-05-99007), Minister of education and science (No. 02.740.11.0325).

  16. Management of combined sewer overflows based on observations from the urbanized Liguori catchment of Cosenza, Italy.

    PubMed

    Piro, P; Carbone, M; Garofalo, G; Sansalone, J J

    2010-01-01

    This paper examines an urbanized catchment in Cosenza, Italy where an off-line basin intercepting CSOs was studied to illustrate reduction in CSO discharges to the Crati River. While the hydrologic transport of pollutant mass is never known a-priori and can be flow-limited, the volumetric requirements of the basin were modeled based on the classic assumption that wet weather flows transport urban and sewer loads in a mass-limited (first-flush) delivery. The volumetric capacity of the basin was varied from 10 to 50 m(3)/ha. Operational basin control was simulated with historical datasets from the Liguori catchment, event-based loading data, and continuous simulation modelling with SWMM. Utilizing data from the catchment, the SWMM simulations were conducted considering the storage basin with or without sedimentation treatment. Results illustrate the potential benefits of the off-line operation for the system with respect to the volume and mass reduction of CSOs into the Crati River. Results demonstrate the importance of particle size distribution (PSD) as an index of basin efficiency, coupled with analysis of the hydrodynamic response of the basin. The basin model attenuated influent PSDs, separating the coarser fraction of the PSD, and reduced the load of influent particulate matter (PM). PMID:20057099

  17. Predicting hydrologic response through a hierarchical catchment knowledgebase: A Bayes empirical Bayes approach

    NASA Astrophysics Data System (ADS)

    Smith, Tyler; Marshall, Lucy; Sharma, Ashish

    2014-02-01

    Making useful Predictions in Ungauged Basins is an incredibly difficult task given the limitations of hydrologic models to represent physical processes appropriately across the heterogeneity within and among different catchments. Here, we introduce a new method for this challenge, Bayes empirical Bayes, that allows for the statistical pooling of information from multiple donor catchments and provides the ability to transfer parametric distributions rather than single parameter sets to the ungauged catchment. Further, the methodology provides an efficient framework with which to formally assess predictive uncertainty at the ungauged catchment. We investigated the utility of the methodology under both synthetic and real data conditions, and with respect to its sensitivity to the number and quality of the donor catchments used. This study highlighted the ability of the hierarchical Bayes empirical Bayes approach to produce expected outcomes in both the synthetic and real data applications. The method was found to be sensitive to the quality (hydrologic similarity) of the donor catchments used. Results were less sensitive to the number of donor catchments, but indicated that predictive uncertainty was best constrained with larger numbers of donor catchments (but still adequate with fewer donors).

  18. Assessment of nutrient entry pathways and dominating hydrological processes in lowland catchments

    NASA Astrophysics Data System (ADS)

    Schmalz, B.; Tavares, F.; Fohrer, N.

    2007-06-01

    The achievement of a good water quality in all water bodies until 2015 is legally regulated since December 2000 for all European Union member states by the European Water Framework Directive (EU, 2000). The aim of this project is to detect nutrient entry pathways and to assess the dominating hydrological processes in complex mesoscale catchments. The investigated Treene catchment is located in Northern Germany as a part of a lowland area. Sandy, loamy and peat soils are characteristic for this area. Land use is dominated by agriculture and pasture. Drainage changed the natural water balance. In a nested approach we examined two catchment areas: a) Treene catchment 517 km2, b) Kielstau catchment 50 km2. The nested approach assists to improve the process understanding by using data of different scales. Therefore these catchments serve not only as an example but the results are transferable to other lowland catchment areas. In a first step the river basin scale model SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) was used successfully to model the water balance. Furthermore the water quality was analysed to distinguish the impact of point and diffuse sources. The results show that the tributaries in the Kielstau catchment contribute high amounts of nutrients, mainly nitrate and ammonium. For the parameters nitrate, ammonium and phosphorus it was observed as a tendency that the annual loads were increasing along the river profile of the Kielstau.

  19. A preliminary investigation of the structure of southern Yucca Flat, Massachusetts Mountain, and CP basin, Nevada Test Site, Nevada, based on geophysical modeling.

    SciTech Connect

    Geoffrey A. Phelps; Leigh Justet; Barry C. Moring, and Carter W. Roberts

    2006-03-17

    New gravity and magnetic data collected in the vicinity of Massachusetts Mountain and CP basin (Nevada Test Site, NV) provides a more complex view of the structural relationships present in the vicinity of CP basin than previous geologic models, helps define the position and extent of structures in southern Yucca Flat and CP basin, and better constrains the configuration of the basement structure separating CP basin and Frenchman Flat. The density and gravity modeling indicates that CP basin is a shallow, oval-shaped basin which trends north-northeast and contains ~800 m of basin-filling rocks and sediment at its deepest point in the northeast. CP basin is separated from the deeper Frenchman Flat basin by a subsurface ridge that may represent a Tertiary erosion surface at the top of the Paleozoic strata. The magnetic modeling indicates that the Cane Spring fault appears to merge with faults in northwest Massachusetts Mountain, rather than cut through to Yucca Flat basin and that the basin is downed-dropped relative to Massachusetts Mountain. The magnetic modeling indicates volcanic units within Yucca Flat basin are down-dropped on the west and supports the interpretations of Phelps and KcKee (1999). The magnetic data indicate that the only faults that appear to be through-going from Yucca Flat into either Frenchman Flat or CP basin are the faults that bound the CP hogback. In general, the north-trending faults present along the length of Yucca Flat bend, merge, and disappear before reaching CP hogback and Massachusetts Mountain or French Peak.

  20. A Preliminary Investigation of The Structure of Southern Yucca Flat, Massachusetts Mountain, and CP Basin, Nevada Test Site, Nevada, Based on Geophysical Modeling

    USGS Publications Warehouse

    Phelps, Geoffrey A.; Justet, Leigh; Moring, Barry C.; Roberts, Carter W.

    2006-01-01

    New gravity and magnetic data collected in the vicinity of Massachusetts Mountain and CP basin (Nevada Test Site, NV) provides a more complex view of the structural relationships present in the vicinity of CP basin than previous geologic models, helps define the position and extent of structures in southern Yucca Flat and CP basin, and better constrains the configuration of the basement structure separating CP basin and Frenchman Flat. The density and gravity modeling indicates that CP basin is a shallow, oval-shaped basin which trends north-northeast and contains ~800 m of basin-filling rocks and sediment at its deepest point in the northeast. CP basin is separated from the deeper Frenchman Flat basin by a subsurface ridge that may represent a Tertiary erosion surface at the top of the Paleozoic strata. The magnetic modeling indicates that the Cane Spring fault appears to merge with faults in northwest Massachusetts Mountain, rather than cut through to Yucca Flat basin and that the basin is downed-dropped relative to Massachusetts Mountain. The magnetic modeling indicates volcanic units within Yucca Flat basin are down-dropped on the west and supports the interpretations of Phelps and KcKee (1999). The magnetic data indicate that the only faults that appear to be through-going from Yucca Flat into either Frenchman Flat or CP basin are the faults that bound the CP hogback. In general, the north-trending faults present along the length of Yucca Flat bend, merge, and disappear before reaching CP hogback and Massachusetts Mountain or French Peak.

  1. Environmental care in agricultural catchments: Toward the communicative catchment

    NASA Astrophysics Data System (ADS)

    Martin, Peter

    1991-11-01

    Substantial land degradation of agricultural catchments in Australia has resulted from the importation of European farming methods and the large-scale clearing of land. Rural communities are now being encouraged by government to take responsibility for environmental care. The importance of community involvement is supported by the view that environmental problems are a function of interactions between people and their environment. It is suggested that the commonly held view that community groups cannot care for their resources is due to inappropriate social institutions rather that any inherent disability in people. The communicative catchment is developed as a vision for environmental care into the future. This concept emerges from a critique of resource management through the catchment metaphors of the reduced, mechanical, and the complex, evolving catchment, which reflect the development of systemic and people-centered approaches to environmental care. The communicative catchment is one where both community and resource managers participate collaboratively in environmental care. A methodology based on action research and systemic thinking (systemic action research) is proposed as a way of moving towards the communicative catchment of the future. Action research is a way of taking action in organizations and communities that is participative and informed by theory, while systemic thinking takes into account the interconnections and relationships between social and natural worlds. The proposed vision, methodology, and practical operating principles stem from involvement in an action research project looking at extension strategies for the implementation of total catchment management in the Hunter Valley, New South Wales.

  2. The relative influence of climate and catchment properties on hydrological drought

    NASA Astrophysics Data System (ADS)

    Van Loon, Anne; Laaha, Gregor; Koffler, Daniel

    2014-05-01

    Studying hydrological drought (a below-normal water availability in groundwater, lakes and streams) is important to society and the ecosystem, but can also reveal interesting information about catchment functioning. This information can later be used for predicting drought in ungauged basins and to inform water management decisions. In this study, we used an extensive Austrian dataset of discharge measurements in clusters of catchments and combine this dataset with thematic information on climate and catchment properties. Our aim was to study the relative effects of climate and catchment characteristics on drought duration and deficit and on hydrological drought typology. Because the climate of the region is roughly uniform, our hypothesis was that the effect of differences of catchment properties would stand out. From time series of precipitation and discharge we identified droughts with the widely-used threshold level approach, defining a drought when a variable falls below a pre-defined threshold representing the regime. Drought characteristics that were analysed are drought duration and deficit. We also applied the typology of Van Loon & Van Lanen (2012). To explain differences in drought characteristics between catchments we did a correlation analysis with climate and catchment characteristics, based on Pearson correlation. We found very interesting patterns in the correlations of drought characteristics with climate and catchment properties: 1) Droughts with long duration (mean and maximum) and composite droughts are related to catchments with a high BFI (high baseflow) and a high percentage of shallow groundwater tables. 2) The deficit (mean and maximum) of both meteorological droughts and hydrological droughts is strongly related to catchment humidity, in this case quantified by average annual precipitation. 3) The hydrological drought types that are related to snow, i.e. cold snow season drought and snow melt drought, occur in catchments that are have a high elevation, steep slopes, a high percentage of crystalline rock, bare rock and glacier. The conclusion of our research is that it is not straightforward to separate the effects of climate and catchment properties on drought, since they are interrelated. This is especially true for mountainous regions where temperature and precipitation are strongly dependent on altitude. We did however see that the duration of drought is more related to catchment storage (catchment properties) and the severity of drought (represented by the drought deficit) is more related to catchment wetness (climate). Van Loon, A.F., and Van Lanen, H.A.J.: A process-based typology of hydrological drought, Hydrology and Earth System Science, 16, p. 1915-1946, doi: 10.5194/hess-16-1915-2012, 2012

  3. The catchment based approach using catchment system engineering

    NASA Astrophysics Data System (ADS)

    Jonczyk, Jennine; Quinn, Paul; Barber, Nicholas; Wilkinson, Mark

    2015-04-01

    The catchment based approach (CaBa) has been championed as a potential mechanism for delivery of environmental directives such as the Water Framework Directive in the UK. However, since its launch in 2013, there has been only limited progress towards achieving sustainable, holistic management, with only a few of examples of good practice ( e.g. from the Tyne Rivers trust). Common issues with developing catchment plans over a national scale include limited data and resources to identify issues and source of those issues, how to systematically identify suitable locations for measures or suites of measures that will have the biggest downstream impact and how to overcome barriers for implementing solutions. Catchment System Engineering (CSE) is an interventionist approach to altering the catchment scale runoff regime through the manipulation of hydrological flow pathways throughout the catchment. A significant component of the runoff generation can be managed by targeting hydrological flow pathways at source, such as overland flow, field drain and ditch function, greatly reducing erosive soil losses. Coupled with management of farm nutrients at source, many runoff attenuation features or measures can be co-located to achieve benefits for water quality and biodiversity. A catchment, community-led mitigation measures plan using the CSE approach will be presented from a catchment in Northumberland, Northern England that demonstrate a generic framework for identification of multi-purpose features that slow, store and filter runoff at strategic locations in the landscape. Measures include within-field barriers, edge of field traps and within-ditch measures. Progress on the implementation of measures will be reported alongside potential impacts on the runoff regime at both local and catchment scale and costs.

  4. Preliminary report on the geology, geophysics and hydrology of USBM/AEC Colorado core hole No. 2, Piceance Creek Basin, Rio Blanco County, Colorado

    USGS Publications Warehouse

    Ege, J.R.; Carroll, R.D.; Welder, F.A.

    1967-01-01

    Approximately 1,400 feet of continuous core was taken .between 800-2,214 feet in depth from USBM/AEC Colorado core hole No. 2. The drill, site is located in the Piceance Creek basin, Rio Blanco County, Colorado. From ground surface the drill hole penetrated 1,120 feet of the Evacuation Creek Member and 1,094 feet of oil shale in the Parachute Creek Member of the Green River Formation. Oil shale yielding more than 20 gallons per ton occurs between 1,260-2,214 feet in depth. A gas explosion near the bottom of the hole resulted in abandonment of the exploratory hole which was still in oil shale. The top of the nahcolite zone is at 1,693 feet. Below this depth the core contains common to abundant amounts of sodium bicarbonate salt intermixed with oil shale. The core is divided into seven structural zones that reflect changes in joint intensity, core loss and broken core due to natural causes. The zone of poor core recovery is in the Interval between 1,300-1,450 feet. Results of preliminary geophysical log analyses indicate that oil yields determined by Fischer assay compare favorably with yields determined by geophysical log analyses. There is strong evidence that analyses of complete core data from Colorado core holes No. 1 and No. 2 reveal a reliable relationship between geophysical log response and oil yield. The quality of the logs is poor in the rich shale section and the possibility of repeating the logging program should be considered. Observations during drilling, coring, and hydrologic testing of USBM/AEC Colorado core hole No. 2 reveal that the Parachute Creek Member of the Green River Formation is the principal aquifer water in the Parachute Creek Member is under artesian pressure. The upper part of the aquifer has a higher hydrostatic head than, and is hydrologically separated from the lower part of the aquifer. The transmissibility of the aquifer is about 3500 gpd per foot. The maximum water yield of the core hole during testing was about 500 gpm. Chemical analyses of water samples indicate that the content of dissolved solids is low, the principal ions being sodium and bicarbonate. Although the hole was originally cored, to a depth of 2,214 feet, ,the present depth is about 2,100 feet. This report presents a preliminary evaluation of core examination, geophysical log interpretation and hydrological tests from the USBM/AEC Colorado core hole No. 2. The cooperation of the U.S. Bureau of Mines is gratefully acknowledged. The reader is referred to Carroll and others (1967) for comparison of USBM/AEC Col0rado core hole No. 1 with USBM/AEC Colorado core hole No. 2.

  5. Geochronological data from the Faxinal coal succession, southern Paran Basin, Brazil: A preliminary approach combining radiometric U-Pb dating and palynostratigraphy

    NASA Astrophysics Data System (ADS)

    Guerra-Sommer, Margot; Cazzulo-Klepzig, Miriam; Menegat, Rualdo; Formoso, Milton Luiz Laquintinie; Basei, Miguel ngelo Stipp; Barboza, Eduardo Guimares; Simas, Margarete Wagner

    2008-03-01

    A radiometric zircon age of 285.4 8.6 Ma (IDTIMS U-Pb) is reported from a tonstein layer interbedded with coal seams in the Faxinal coalfield, Rio Grande do Sul, Brazil. Calibration of palynostratigraphic data with the absolute age shows that the coal depositional interval in the southern Paran Basin is constrained to the Sakmarian. Consequently, the basal Gondwana sequence in the southern part of the basin should lie at the Carboniferous-Permian boundary, not within the Sakmarian as previously considered. The new results are significant for correlations between the Paran Basin and the Argentinian Paganzo Basin (302 6 Ma and 288 7 Ma) and with the Karoo Basin, specifically with the top of the Dwyka Tillite (302 3 Ma and 299.2 3.2 Ma) and the lowermost Ecca Group (288 3 Ma and 289.6 3.8 Ma). The evidence signifies widespread latest Carboniferous volcanic activity in western Gondwana.

  6. Runoff Production in the Upper Rio Chagres Catchment, Panama

    NASA Astrophysics Data System (ADS)

    Niezialek, J. M.; Ogden, F. L.

    2003-12-01

    Runoff production in watersheds in the seasonal tropics is governed by a number of factors. The mountainous 414 sq. km upper Rio Chagres watershed offers a unique opportunity to better understand the runoff production mechanisms in seasonal tropical catchments through data analysis and modeling. The upper Rio Chagres catchment provides the majority of inflows to the Panama Canal, has been monitored for over 60 years as part of canal operations. Discharge data are available at both the catchment outlet (Chico gaging station) and an internal catchment location (Rio Piedras gaging station). There are also seven tipping bucket recording rain gages in and around the catchment. Analysis of runoff data reveals anomalously-high runoff production efficiencies early in the wet season. Furthermore, the existence of two quasi-stable base flow regimes during the wet season imply critical threshold storages. Initial field studies have shown that the soils are water repellent during the dry season. Runoff data from the 80 sq. km Rio Piedras subcatchment reveal ephemeral flows throughout the wet season, indicating significant heterogeneity in runoff production and deep groundwater circulation. Preliminary hydrologic modeling is performed with the Sacramento Soil Moisture Accounting Model (SAC-SMA), calibrated using data from 1988 and verified using data from 1989. Further modeling on the flood of 28-31 December, 2000 is also performed. Modeling using the distributed parameter GSSHA model combined with the Sacramento groundwater module allows simulation of distributed runoff. However, the role of interception by the triple-layer tropical canopy and the magnitude of evapotranspiration are uncertain. New data collection is proposed in the Rio Chagres catchment to help quantify interception and evapotranspiration. This instrumentation will include measurements of rainfall above the canopy, cloud stripping, stemflow, throughfall, soil moisture, groundwater, interflow, evapotranspiration and overland runoff. Intensive field observations during the transition from dry to wet season are proposed to develop predictive understanding of unusually-high runoff production efficiencies.

  7. Catchment-scale biogeography of riverine bacterioplankton

    PubMed Central

    Read, Daniel S; Gweon, Hyun S; Bowes, Michael J; Newbold, Lindsay K; Field, Dawn; Bailey, Mark J; Griffiths, Robert I

    2015-01-01

    Lotic ecosystems such as rivers and streams are unique in that they represent a continuum of both space and time during the transition from headwaters to the river mouth. As microbes have very different controls over their ecology, distribution and dispersion compared with macrobiota, we wished to explore biogeographical patterns within a river catchment and uncover the major drivers structuring bacterioplankton communities. Water samples collected across the River Thames Basin, UK, covering the transition from headwater tributaries to the lower reaches of the main river channel were characterised using 16S rRNA gene pyrosequencing. This approach revealed an ecological succession in the bacterial community composition along the river continuum, moving from a community dominated by Bacteroidetes in the headwaters to Actinobacteria-dominated downstream. Location of the sampling point in the river network (measured as the cumulative water channel distance upstream) was found to be the most predictive spatial feature; inferring that ecological processes pertaining to temporal community succession are of prime importance in driving the assemblages of riverine bacterioplankton communities. A decrease in bacterial activity rates and an increase in the abundance of low nucleic acid bacteria relative to high nucleic acid bacteria were found to correspond with these downstream changes in community structure, suggesting corresponding functional changes. Our findings show that bacterial communities across the Thames basin exhibit an ecological succession along the river continuum, and that this is primarily driven by water residence time rather than the physico-chemical status of the river. PMID:25238398

  8. Catchment-scale biogeography of riverine bacterioplankton.

    PubMed

    Read, Daniel S; Gweon, Hyun S; Bowes, Michael J; Newbold, Lindsay K; Field, Dawn; Bailey, Mark J; Griffiths, Robert I

    2015-02-01

    Lotic ecosystems such as rivers and streams are unique in that they represent a continuum of both space and time during the transition from headwaters to the river mouth. As microbes have very different controls over their ecology, distribution and dispersion compared with macrobiota, we wished to explore biogeographical patterns within a river catchment and uncover the major drivers structuring bacterioplankton communities. Water samples collected across the River Thames Basin, UK, covering the transition from headwater tributaries to the lower reaches of the main river channel were characterised using 16S rRNA gene pyrosequencing. This approach revealed an ecological succession in the bacterial community composition along the river continuum, moving from a community dominated by Bacteroidetes in the headwaters to Actinobacteria-dominated downstream. Location of the sampling point in the river network (measured as the cumulative water channel distance upstream) was found to be the most predictive spatial feature; inferring that ecological processes pertaining to temporal community succession are of prime importance in driving the assemblages of riverine bacterioplankton communities. A decrease in bacterial activity rates and an increase in the abundance of low nucleic acid bacteria relative to high nucleic acid bacteria were found to correspond with these downstream changes in community structure, suggesting corresponding functional changes. Our findings show that bacterial communities across the Thames basin exhibit an ecological succession along the river continuum, and that this is primarily driven by water residence time rather than the physico-chemical status of the river. PMID:25238398

  9. Geomorphic (de-) coupling of hillslope and channel systems within headwater catchments in two subarctic tributary valleys, Nordfjord, Western Norway

    NASA Astrophysics Data System (ADS)

    Laute, Katja; Beylich, Achim A.

    2010-05-01

    Hillslopes occupy large areas of the earth surface. Studying the characteristics, development and interaction of hillslopes as components of the geomorphic hillslope-channel coupling process-response system will improve the understanding of the complex response of mountain landscape formation. The rates of hillslope processes are exceptionally varied and affected by many influences of varying intensity. Hillslope-channel coupling and sediment storage within slopes are important factors that influence sediment delivery through catchments, especially in steep environments. Within sediment transfers from sources to sinks in drainage basins, hillslopes function as a key element concerning sediment storage, both for short term periods as between rainstorms as well as for longer periods in colluvial deposits. This PhD project is part of the NFR funded SedyMONT-Norway project within the ESF TOPO-EUROPE SedyMONT (Timescales of sediment dynamics, climate and topographic change in mountain landscapes) programme. The focus of this study is on geomorphic hillslope-channel coupling or de-coupling and sediment transport within four distinct headwater areas of the Erdalen and Bdalen catchments in the Nordfjord valley-fjord system (inner Nordfjord, Western Norway). Both catchments can be described as steep, U-shaped and glacier-fed, subarctic tributary valleys. Approximately 14% of the 49 km2 large headwater area of Erdalen is occupied by hillslope deposits; in Bdalen hillslope deposits occupy 12% of the 42 km2 large headwater area. The main aims of the study are to present preliminary findings on (i) the identification of possible sediment sources and delivery pathways within the headwater areas of the catchments, (ii) to analyze the development of hillslope-channel coupling / de-coupling from postglacial to contemporary timescales as well as (iii) to investigate the current degree of geomorphic hillslope-channel coupling within the different headwater catchments and (iv) to determine differently acting mass movement processes. A process-based approach is applied to assess the importance of hillslope sediment production, storage and transport throughout the catchments, including orthophoto-interpretation, hillslope profile surveying, photo monitoring, geomorphological mapping, GIS and DEM computing as well as a combination of different field techniques for bed load monitoring. Appropriate hillslope test sites within the headwater catchments are selected in order to fulfill the main aims of this study as well as to monitor contemporary rates of hillslope fluxes. The designed monitoring instrumentation of the slope test sites includes nets, stone tracer lines, wooden sticks, peg lines, slop wash traps and remote site monitoring cameras. Hillslope profile surveying, geomorphological mapping and measurements of solute yields from the slope systems are carried out at each test site. Channel longitudinal- and cross profiles are measured in defined test stretches of the first order streams, located downhill of the slope test sites. Within the same channel test stretches extensive pebble counts (grain size, grain shape) are conducted seasonally and tracer lines are installed in order to trace different bed load components. The four selected headwater areas are characterized by different intensities of hillslope-channel coupling, mainly due to the distinct valley morphometries affected by the glacial inheritance of the Nordfjord region. Where hillslope-channel coupling exists, primary coarse material is delivered from the hillslopes into the channels via snow avalanches. These coarse grained and angular components can be traced within the channel test stretches. Research on the complex evolution of hillslope-channel (de-) coupling over time and contemporary sediment transfer fluxes contributes to a better understanding of possible trends of mountain landscape development.

  10. Groundwater Resources Evolution in Degrading Permafrost Environments: A Small Catchment-Scale Study in Northern Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Molson, John; Lemieux, Jean-Michel; Fortier, Richard; Therrien, Rene; Ouellet, Michel; Barth, Johannes; van Geldern, Robert; Cochand, Marion; Sottas, Jonathan; Murray, Renaud; Banville, David

    2015-04-01

    A two square kilometre catchment in a discontinuous permafrost zone near the Inuit community of Umiujaq on the eastern shore of Hudson Bay in Northern Quebec, Canada, is being investigated to determine the impact of permafrost degradation on groundwater resources. The catchment, which became deglaciated about 7500 years ago, lies in a valley which includes about 30-40 m of glacial-fluvial and marine Quaternary sediments. Permafrost mounds at the site extend from a few meters below ground surface to depths of about 10-30 m. Instrumentation has been installed to measure groundwater levels and temperature, as well as groundwater and surface water geochemistry, isotope signatures (including ?18O and 3H) and stream flow. Preliminary groundwater isotope data reflect depleted ?18O signals that differ from expected values for local groundwater, possibly representing permafrost thaw. In addition, stable water isotopes indicate evaporation from shallow thermokarst lakes. Meteorological conditions including air temperatures, precipitation and snowpack are also being monitored. Near-surface geophysical surveys using electrical resistivity tomography (ERT), induced polarization tomography (IPT), georadar and seismic refraction tomography have been carried out to characterize the catchment and to build a 3D geological site model. A numerical model of coupled groundwater flow and heat transport, including thermal advection, conduction, freeze-thaw and latent heat, is being developed for the site to help develop the conceptual model and to assess future impacts of permafrost degradation due to climate warming. The model (Heatflow/3D) includes nonlinear functions for the temperature-dependent unfrozen moisture content and relative permeability, and has been tested against analytical solutions and using benchmarks developed by the INTERFROST modelling consortium. A conceptual 2D vertical-plane model including several permafrost mounds along a 1 km section shows dynamic seasonal behavior with preferential melting from below due to sub-permafrost horizontal groundwater flow and upward flow to surface water through taliks. Under current environmental conditions, the simulations suggest the remaining permafrost in the basin could completely thaw within 50 years. The long-term monitoring program in the catchment will help develop optimal investigative methods for monitoring hydrogeological systems and groundwater resources under permafrost-degrading conditions, and will help determine how new groundwater resources may become available for northern communities as permafrost thaws and recharge to aquifers increases.

  11. Geochemical effects of CO2 injection on produced water chemistry at an enhanced oil recovery site in the Permian Basin of northwest Texas, USA: Preliminary geochemical and Li isotope results

    NASA Astrophysics Data System (ADS)

    Pfister, S.; Gardiner, J.; Phan, T. T.; Macpherson, G. L.; Diehl, J. R.; Lopano, C. L.; Stewart, B. W.; Capo, R. C.

    2014-12-01

    Injection of supercritical CO2 for enhanced oil recovery (EOR) presents an opportunity to evaluate the effects of CO2 on reservoir properties and formation waters during geologic carbon sequestration. Produced water from oil wells tapping a carbonate-hosted reservoir at an active EOR site in the Permian Basin of Texas both before and after injection were sampled to evaluate geochemical and isotopic changes associated with water-rock-CO2 interaction. Produced waters from the carbonate reservoir rock are Na-Cl brines with TDS levels of 16.5-34 g/L and detectable H2S. These brines are potentially diluted with shallow groundwater from earlier EOR water flooding. Initial lithium isotope data (δ7Li) from pre-injection produced water in the EOR field fall within the range of Gulf of Mexico Coastal sedimentary basin and Appalachian basin values (Macpherson et al., 2014, Geofluids, doi: 10.1111/gfl.12084). Pre-injection produced water 87Sr/86Sr ratios (0.70788-0.70795) are consistent with mid-late Permian seawater/carbonate. CO2 injection took place in October 2013, and four of the wells sampled in May 2014 showed CO2 breakthrough. Preliminary comparison of pre- and post-injection produced waters indicates no significant changes in the major inorganic constituents following breakthrough, other than a possible drop in K concentration. Trace element and isotope data from pre- and post-breakthrough wells are currently being evaluated and will be presented.

  12. Deep Drilling to Decipher Potential Interaction Between Shallow and Deep Fluid Systems: Preliminary Results From the INFLUINS Drilling Campaign in the Thuringian Basin, Central Germany

    NASA Astrophysics Data System (ADS)

    Kukowski, N.; Totsche, K. U.; Methe, P.; Goepel, A.; Abratis, M.; Habisreuther, A.; Kunkel, C.; Ward, T.

    2014-12-01

    To shed light on the coupled dynamics of near surface and deep fluid systems in a sedimentary basin on various scales, ranging from the pore scale to the extent of an entire basin, is the overall goal of INFLUINS (INtegrated FLuid dynamics IN Sedimentary basins). To do so is essential to understand the functioning of sedimentary basins fluid systems. An integral INFLUINS topic also is the potential interaction of aquifers within a basin and at its rims. Regionally, INFLUINS is focusing on the Thuringian basin, a well-confined, intra-continental sedimentary basin in central Germany as a natural geo-laboratory. The Thuringian basin is composed of sedimentary rocks from the latest Paleozoic and mainly Triassic and particularly suited to undertake such research as it is of relative small size, about 50 times 100 km, easily accessible, and quite well known from previous studies. INFLUINS consists on several projects tightly connected to each other and coming from various disciplines of geosciences including among others geophysics, hydrogeology, sedimentology, mineralogy, and remote sensing. A deep drilling campaign, which took place close to Erfurt in the center of the basin in summer 2013, is one of the main achievements of INFLUINS. In preparation for deep drilling, in 2011, we conducted an extensive seismic reflection site survey, in the framework of which the center of the basin down to the top basement was imaged in high quality. Drilling went down to a depth of 1179 m, drilling Triassic rocks from Keuper to lower Buntsandstein and led to more than 500 m of cores of excellent quality and more than 600 cuttings samples. Down-hole geophysical logging over the entire depth of the drill hole is complemented with Multi Sensor Core Logging leading to an extensive geophysical data set with a spatial resolution up to the cm-scale. Here, we present overall results of the drilling campaign and focus on the boundaries between major groups as well as between prominent beds including e.g. rock salt and other pronounced aquitards.

  13. The large-scale landslide risk classification in catchment scale

    NASA Astrophysics Data System (ADS)

    Liu, Che-Hsin; Wu, Tingyeh; Chen, Lien-Kuang; Lin, Sheng-Chi

    2013-04-01

    The landslide disasters caused heavy casualties during Typhoon Morakot, 2009. This disaster is defined as largescale landslide due to the casualty numbers. This event also reflects the survey on large-scale landslide potential is so far insufficient and significant. The large-scale landslide potential analysis provides information about where should be focused on even though it is very difficult to distinguish. Accordingly, the authors intend to investigate the methods used by different countries, such as Hong Kong, Italy, Japan and Switzerland to clarify the assessment methodology. The objects include the place with susceptibility of rock slide and dip slope and the major landslide areas defined from historical records. Three different levels of scales are confirmed necessarily from country to slopeland, which are basin, catchment, and slope scales. Totally ten spots were classified with high large-scale landslide potential in the basin scale. The authors therefore focused on the catchment scale and employ risk matrix to classify the potential in this paper. The protected objects and large-scale landslide susceptibility ratio are two main indexes to classify the large-scale landslide risk. The protected objects are the constructions and transportation facilities. The large-scale landslide susceptibility ratio is based on the data of major landslide area and dip slope and rock slide areas. Totally 1,040 catchments are concerned and are classified into three levels, which are high, medium, and low levels. The proportions of high, medium, and low levels are 11%, 51%, and 38%, individually. This result represents the catchments with high proportion of protected objects or large-scale landslide susceptibility. The conclusion is made and it be the base material for the slopeland authorities when considering slopeland management and the further investigation.

  14. Water erosion processes in an olive orchard catchment using a multidisciplinary approach

    NASA Astrophysics Data System (ADS)

    Guzmán, Gema; Taguas, Encarnación V.; Gómez, José A.

    2015-04-01

    The implementation of soil and water conservation measures in agricultural areas such as, buffer strips, cover crops or check dams, is an important issue in order to maintain soil quality. As these measures involve a significant maintenance and investment, their efficiency must be optimized as much as possible. La Conchuela is an olive orchard catchment of 8.0 ha located in Córdoba (southern Spain) where runoff and sediment losses have been measured at hillslope and catchment scale since 2006. Three different approaches were used to evaluate the behavior of sediment displacement within and from the catchment: soil properties and water erosion and, sediment tracers. During the hydrological year 2010-2011, runoff and soil loss were measured at plot and catchment scale. Chemical (organic carbon and available phosphorus) and physical (particle size distribution) properties were determined in the top 5 cm of the soil and in the sediment collected at plot and catchment scale. Both set of measures were grouped and compared distinguishing between zones (lanes and tree rows) and scales (plot and catchment scale). Finally, these results were compared to the ones obtained using magnetite at hillslope scale regarding soil redistribution after rainfall events during 2008-2010. This study presents a preliminary characterization of the environmental processes occurring during water erosion events to identify significant sources of sediment at hillslope scale and their comparison to the catchment outlet in order to implement local soil and water conservation measures improving their efficiency and therefore reducing the costs associated to them.

  15. On the trail of 'hidden streamflow' in Luxembourgish catchments

    NASA Astrophysics Data System (ADS)

    Stewart, Michael; Pfister, Laurent; Morgenstern, Uwe; Martinez-Carreras, Nuria; Gourdol, Laurent; Klaus, Julian; McDonnell, Jeffrey

    2014-05-01

    Tritium measurements are being carried out in well-studied catchments in the Attert sub-basin of the Alzette River in Luxembourg to investigate transit times of baseflow from the various lithologies in the area. Rock-types vary from sandstone with high permeability to marl and schist with low permeabilities. In contrast to other methods, tritium reveals the full spectrum of ages present in streams including 'hidden streamflow' (i.e. water older than that measurable by stable isotope or conservative tracer methods) Stewart et al. (2012). In principle, it can also provide ages for individual samples and therefore reveal variations in age with flow if measurements are accurate enough. However, difficulties arise in determining the tritium input function and from ambiguous age solutions due to the past input of thermonuclear tritium. Previous and concurrent geochemical and stable isotope studies are providing complementary information about the systems (e.g. geological controls on catchment storage, mixing potential, isotopic signatures in streamflow) Pfister et al. (2014). Results to date are showing that old water with mean transit times of about 18 years flow from catchments dominated by sandstone at medium to low flows. These streams also have very homogeneous δD values at such flows showing large storages and mixing potentials. On the other hand, catchments dominated by marl and schist show varying mean transit times ranging from 2 to 20 years depending on flows, although data is limited. The δD values of these streams are scattered and have a decreasing trend with streamflow showing event and seasonal rainfall influence, and thus small storage capacities and mixing potentials. It appears that 'hidden streamflow' is alive and well, and living in Luxembourg! Pfister L. et al. 2014: Catchment storage, baseflow isotope signatures and basin geology: Is there a connection? In preparation. Stewart, M.K., Morgenstern, U., McDonnell, J.J., Pfister, L. 2012: The 'hidden' streamflow challenge in catchment hydrology: A call to action for streamwater transit time analysis. Hydrological Processes 26(13), 2061-2066.

  16. Preliminary applications of Landsat images and aerial photography for determining land-use, geologic, and hydrologic characteristics, Yampa River basin, Colorado and Wyoming

    USGS Publications Warehouse

    Heimes, F.J.; Moore, G.K.; Steele, T.D.

    1978-01-01

    Expanded energy- and recreation-related activities in the Yampa River basin, Colorado and Wyoming, have caused a rapid increase in economic development which will result in increased demand and competition for natural resources. In planning for efficient allocation of the basin 's natural resources, Landsat images and small-scale color and color-infrared photographs were used for selected geologic, hydrologic and land-use applications within the Yampa River basin. Applications of Landsat data included: (1) regional land-use classification and mapping, (2) lineament mapping, and (3) areal snow-cover mapping. Results from the Landsat investigations indicated that: (1) Landsat land-use classification maps, at a regional level, compared favorably with areal land-use patterns that were defined from available ground information, (2) lineaments were mapped in sufficient detail using recently developed techniques for interpreting aerial photographs, (3) snow cover generally could be mapped for large areas with the exception of some densely forested areas of the basin and areas having a large percentage of winter-season cloud cover. Aerial photographs were used for estimation of turbidity for eight stream locations in the basin. Spectral reflectance values obtained by digitizing photographs were compared with measured turbidity values. Results showed strong correlations (variances explained of greater than 90 percent) between spectral reflectance obtained from color photographs and measured turbidity values. (Woodard-USGS)

  17. Hydrochemical responses among nested catchments of the Sleepers River Research Watershed.

    NASA Astrophysics Data System (ADS)

    Sebestyen, S. D.; Boyer, E. W.; Shanley, J. B.; Kendall, C.

    2005-12-01

    We are probing chemical and isotopic tracers of dissolved organic carbon (DOC) and nitrate over both space and time to determine how stream nutrient dynamics change with increasing basin size and differ with flow conditions. At the Sleepers River Research Watershed in northeastern Vermont, USA, 20 to 30 nested sub-basins that ranged in size from 3 to 11,000 ha were sampled repeatedly under baseflow conditions. These synoptic surveys showed a pattern of heterogeneity in headwaters that converged to a consistent response at larger basin sizes and is consistent with findings of other studies. In addition to characterizing spatial patterns under baseflow, we sampled rainfall and snowmelt events over a gradient of basin sizes to investigate scaling responses under different flow conditions. During high flow events, DOC and nitrate flushing responses varied among different basins where high-frequency event samples were collected. While the DOC and nitrate concentration patterns were similar at four headwater basins, the concentration responses of larger basins were markedly different in that the concentration patterns, flushing duration, and maximum concentrations were attenuated from headwaters to the largest basin. We are using these data to explore how flow paths and solute mixing aggregate. Overall, these results highlight the complexities of understanding spatial scaling issues in catchments and underscore the need to consider event responses of hydrology and chemistry among catchments.

  18. Factors affecting ground-water exchange and catchment size for Florida lakes in mantled karst terrain

    USGS Publications Warehouse

    Lee, Terrie Mackin

    2002-01-01

    In the mantled karst terrain of Florida, the size of the catchment delivering ground-water inflow to lakes is often considerably smaller than the topographically defined drainage basin. The size is determined by a balance of factors that act individually to enhance or diminish the hydraulic connection between the lake and the adjacent surficial aquifer, as well as the hydraulic connection between the surficial aquifer and the deeper limestone aquifer. Factors affecting ground-water exchange and the size of the ground-water catchment for lakes in mantled karst terrain were examined by: (1) reviewing the physical and hydrogeological characteristics of 14 Florida lake basins with available ground-water inflow estimates, and (2) simulating ground-water flow in hypothetical lake basins. Variably-saturated flow modeling was used to simulate a range of physical and hydrogeologic factors observed at the 14 lake basins. These factors included: recharge rate to the surficial aquifer, thickness of the unsaturated zone, size of the topographically defined basin, depth of the lake, thickness of the surficial aquifer, hydraulic conductivity of the geologic units, the location and size of karst subsidence features beneath and onshore of the lake, and the head in the Upper Floridan aquifer. Catchment size and the magnitude of ground-water inflow increased with increases in recharge rate to the surficial aquifer, the size of the topographically defined basin, hydraulic conductivity in the surficial aquifer, the degree of confinement of the deeper Upper Floridan aquifer, and the head in the Upper Floridan aquifer. The catchment size and magnitude of ground-water inflow increased with decreases in the number and size of karst subsidence features in the basin, and the thickness of the unsaturated zone near the lake. Model results, although qualitative, provided insights into: (1) the types of lake basins in mantled karst terrain that have the potential to generate small and large amounts of ground-water inflow, and (2) the location of ground-water catchments that could be managed to safeguard lake water quality. Knowledge of how ground-water catchments are related to lakes could be used by water-resource managers to recommend setback distances for septic tank drain fields, agricultural land uses, and other land-use practices that contribute nutrients and major ions to lakes.

  19. From rainfall to rivers: A comparison of modelled and measured stable water isotopes in precipitation and river catchments at a global scale

    NASA Astrophysics Data System (ADS)

    Halder, Janine; Terzer, Stefan; Wassenaar, Leonard I.; Araguas-Araguas, Luis; Aggarwal, Pradeep K.

    2015-04-01

    Rivers are a crucial link in the global hydrological cycle as they discharge precipitation, groundwater, and water stored in snowpacks and glaciers back to the world oceans. However, there are essential gaps in hydrological data between rainfall, infiltration, and river discharge to the world oceans. Stable water isotopes are used to trace sources of precipitation and river water, unravel hydrological processes, as well as to assess the water balance of watersheds. With the widespread adoption of laser absorption spectroscopy for water isotope analysis, there is growing potential for an improved integration and application of isotope methods, combined with traditional quantitative and qualitative hydrological studies of large rivers. The Global Network of Isotopes in Rivers (GNIR) has been established a decade ago and aims to fill the informational data gaps between rainfall and river discharge. Here we report the results of a preliminary evaluation of the GNIR data holdings for about 250 river catchments, using measured and modelled stable water isotope compositions. A regionalized, cluster-based precipitation isotope model (RCWIP) was used to compare measured to predicted isotope compositions of riverine catchments. The results help to identify knowledge gaps and to improve the understanding of catchment scale processes of our world river basins. Our analysis suggests that the global GNIR river stations can be clustered into 6 different groups, as a function of their seasonal variation in stable isotope composition. A sinusoidal function reveals that there are periodic phases within each river grouping, which shows that, despite different catchment effects (e.g. river length, width, or amount of baseflow contribution), direct seasonal run-off (isotopic) patterns are preserved. The periodicity of the isotopic run-off signal, however, is dependent on river catchment latitude and snow or glacier meltwater-contributions. The importance of direct precipitation and run-off to the river discharge is confirmed by the strong co- variation of the isotope composition of precipitation and river water on a global scale. However, as most of the world's rivers are impacted to some degree by natural or man-made reservoirs, mixing processes of different water sources and of precipitation from different seasons are observed. The model predicted isotope composition of rivers correlates well with measured river isotope composition, however, some rivers strongly deviate. These deviations are located in arid regions that experience intense evaporation processes, or watersheds having important contributions from glacier-meltwater or permafrost.

  20. Dominant controls on catchment hydrological functions: what can we learn from biological and isotopic tracers?

    NASA Astrophysics Data System (ADS)

    Pfister, L.; Klaus, J.; Wetzel, C. E.; Stewart, M. K.; McDonnell, J.; Martinez Carreras, N.

    2014-12-01

    One emerging and important control on catchment hydrological functions of water storage, mixing and release is bedrock geology. Until today, catchment-based work has been limited by small ranges of rock types in adjacent basins. Moreover, conventional hydrological tracer approaches suffer from limitations inherent to the large storages related to certain bedrock types (e.g. the damping of stable isotope tracer signatures in deep storage catchments and obliteration of output signals at larger spatial scales). Here, we show how a multi-tracer approach, based on terrestrial diatoms and different stable and radioactive isotopic tracers can help refining our understanding of the dominant controls on catchment hydrological functions, especially the role of bedrock geology. We present new data and results from a nested catchment set-up, located in the Alzette River basin in Luxembourg (Europe). These 16 catchments (with sizes ranging from 0.47 to 285 km2) are characterized by clean and mixed assemblages of geology and land use. We have monitored these systems since 2002, including meteorological variables (precipitation, air temperature, etc.), as well as 15 minute discharge. Additional parameters have been monitored bi-weekly and at the event time scale, including geochemical and isotopic (3H, D, 18O) tracers, as well as terrestrial diatom communities in streamwater. Our results show that water balance derived dynamic storage significantly differs across the 16 catchments and scales. Catchment mixing potential inferred from standard deviations in stream baseflow ∂D (as a proxy for the damping of isotopic signatures in precipitation), as well as tritium-derived baseflow transit times, both exhibit a significant spatial variability, but strong correlation to bedrock pemeability. Terrestrial diatom assemblages in streamwater, as a proxy for rapid flow pathway connectedness to the stream network, are highly variable across the study catchments but also show strong correlation with geology. Our work suggests a hierarchy of controls on catchment function. Eventually, geology (namely bedrock permeability) trumps other physiographic characteristics such as land use or topography in controlling fundamental catchment functions of storage, mixing and release.

  1. Derivation of Geomorphological Instantaneous Unit Hydrographs for Ungauged Sites based on Catchment Self Similarity Properties

    NASA Astrophysics Data System (ADS)

    Chavan, Sagar; Srinivas Vemavarapu, Venkata

    2015-04-01

    Hydrologists extensively use Horton-Strahler (H-S) scheme for ordering (classification) of streams in a catchment. The ordered network forms the basis to determine H-S ratios that find use in modeling hydrological response of the catchment and in establishing relations with the fractal nature of channel network in the catchment. However, utility of H-S ratios has attracted criticism owing to (i) their dependence on the threshold area used for initiation of stream network and (ii) their sensitivity to the position of outlet of catchment. This implies that estimates of H-S ratios and inferences drawn from analysis of a river network that is classified based on H-S ordering scheme are conditional on threshold area, which is undesirable. To overcome these limitations, researchers are dedicating their efforts to arrive at an effective strategy that alleviates the dependence of H-S ratios on threshold area used for extraction of stream network in a catchment. Recently, Moussa (2009) proposed that artefacts associated with estimation of H-S ratios could be overcome if self-similarity properties are applicable to channel network. Equivalent H-S ratios that are independent of threshold area could be estimated for a catchment by using morphometric descriptors determined based on self-similarity properties of channel network in the catchment. Moussa (2009) examined applicability of self-similarity properties on seven catchments in France having area ranging from 738 sq.km to 5346 sq.km. There is dearth of attempts to examine potential of the strategy outside France. In this perspective, hypothesis of self-similarity is verified for stream networks in 201 catchments located in Mahanadi, Godavari, Krishna and Cauvery river basins, whose sizes vary from 160 sq.km to 311,150 sq.km. The river basins cover about 794,515 sq.km area in central and southern parts of India. Results indicated that self-similarity based strategy is effective for the Indian catchments irrespective of their size. Results obtained from the investigations would be presented and discussed. Further, utility of information determined on morphometric descriptors of the catchments in estimating equivalent H-S ratios and subsequently constructing Geomorphological Instantaneous Unit Hydrographs (GIUH) for various ungauged locations in the study area would be demonstrated.

  2. Nonparametric method for estimating the effects of climatic and catchment characteristics on mean annual evapotranspiration

    NASA Astrophysics Data System (ADS)

    Shao, Quanxi; Traylen, Anthony; Zhang, Lu

    2012-03-01

    It is now well known that forested catchments have higher evapotranspiration than grassed catchments. Models for mean annual evapotranspiration have been developed to quantify catchment scale differences in mean annual evapotranspiration. Zhang et al. (2001) developed a simple, one parameter, model for the relationships between evapotranspiration and vegetation cover by evaluating the differences of model parameter values for different vegetation covers. However, other factors such as climate and catchment topography may also affect evapotranspiration and therefore the model parameter. Simple models acknowledging only categorical vegetation cover (forested, mixed, and grassed) may introduce some uncertainty, and more seriously, lead to inconsistent conclusions regarding relationships between vegetation cover and evapotranspiration. Zhang et al. (2004) investigated possible inclusion of climatic factors and catchment characteristics to improve the estimation of mean annual evapotranspiration by modeling the residuals of the model parameter via a stepwise linear regression. In this paper we propose the use of a multivariate adaptive regression spline (MARS) model for estimating the model parameter. In contrast to a simple stepwise regression, the MARS model provides not only insight into the interactions between explanatory factors but also a potential for prediction for ungauged basins as long as the values of explanatory factors are within the domain of calibration catchments. The MARS model is able to determine statistically significant factors and therefore is a powerful tool to identify important factors and their interactions. Using 241 Australian catchments where climate factors and catchment characteristics are available, we found the following significant terms affecting the mean annual evapotranspiration. (1) The functional relationship with the number of months that peak precipitation follows peak potential evapotranspiration (PfE) states that closer phase between precipitation and potential evapotranspiration results in less streamflow. (2) The interactions between coefficient of variation of precipitation and average storm depth shows that the value of the model parameter is smaller when the coefficient of variance of precipitation is larger than 2.24 and the average storm depth is less than 8.70 mm d-1. (3) The interaction between relief ratio and average storm depth term shows that both larger average storm depth in flat catchments and smaller average storm depth in hilly catchments result in more streamflow. (4) The interaction between relief ratio and forest coverage reveals that for flat catchments with reasonable forest cover, increasing forest cover generally results in more mean annual evapotranspiration and less mean annual streamflow. The performance of the MARS model was assessed by a calibration-testing procedure to support its usage for prediction for ungauged basins.

  3. Transit times of water particles in the vadose zone across catchment states and catchments functional units

    NASA Astrophysics Data System (ADS)

    Sprenger, Matthias; Weiler, Markus

    2014-05-01

    Understanding the water movement in the vadose zone and its associated transport of solutes are of major interest to reduce nutrient leaching, pollution transport or other risks to water quality. Soil physical models are widely used to asses such transport processes, while the site specific parameterization of these models remains challenging. Inverse modeling is a common method to adjust the soil physical parameters in a way that the observed water movement or soil water dynamics are reproduced by the simulation. We have shown that the pore water stable isotope concentration can serve as an additional fitting target to simulate the solute transport and water balance in the unsaturated zone. In the presented study, the Mualem- van Genuchten parameters for the Richards equation and diffusivity parameter for the convection-dispersion equation have been parameterized using the inverse model approach with Hydrus-1D for 46 experimental sites of different land use, topography, pedology and geology in the Attert basin in Luxembourg. With the best parameter set we simulated the transport of a conservative solute that was introduced via a pulse input at different points in time. Thus, the transit times in the upper 2 m of the soil for different catchment states could be inferred for each location. It has been shown that the time a particle needs to pass the -2 m depth plane highly varies from the systems state and the systems forcing during and after infiltration of that particle. Differences in transit times among the study sites within the Attert basin were investigated with regards to its governing factors to test the concept of functional units. The study shows the potential of pore water stable isotope concentration for residence times and transport analyses in the unsaturated zone leading to a better understanding of the time variable subsurface processes across the catchment.

  4. Assessing catchment hydrological functioning using discharge recession analysis based on the Kirchner's method. A case study in the Ardèche catchment (France)

    NASA Astrophysics Data System (ADS)

    Adamovic, Marko; Braud, Isabelle; Branger, Flora; Krier, Robert

    2013-04-01

    Catchments show a high degree of heterogeneity and variability, both in space and time. In order to deal with spatial heterogeneity and process variability in more efficient and more "natural and realistic" manner, model simplifications are needed. Governing equations such as the Darcy or Richards' equation, which are inherent in many hydrological models, are suitable for local scales. However, their application at much larger scales (e.g. catchment scale) remains problematic. The linear reservoir is a well-known and common approach in many catchment-based hydrological models. However, reality shows that those linear equations might not be representative enough for describing hydrological catchment behavior. Kirchner (2009), proposed a simple approach representing catchment behavior as a non-linear reservoir model, assuming that discharge at the outlet is only a function of catchment storage. He also proposed a method to determine non-linear reservoir parameters for this simple bucket model. The objective of this study is to investigate whether this approach is applicable to the Ardèche catchment (2355 km2), located in the southern part of France. The catchment is influenced by a Mediterranean climate with seasonal heavy rainfall events during autumn. The northern and north-western part of the catchment is characterized by steep slopes and igneous and metamorphic rock formations. A further objective is to relate the estimated parameters of the first-order dynamical system to catchment characteristics, in order to be able to develop a distributed model, adapted to the catchment response variability. The challenge for the Kirchner's method is the high geological and pedological heterogeneity of the Ardèche basin. We apply the Kirchner's method to 6 sub-catchments of the Ardèche ranging from 3.9 to 200 km2 using hourly rainfall and discharge data, in order to identify the discharge sensitivity function. We use the obtained corresponding parameters in a simple bucket model similar to the one proposed by Kirchner (2009). To have more representative potential evapotranspiration data used in the model, we introduce crop coefficient seasonality to better represent the data. Performance measurements with the Nash-Sutcliffe coefficient show performances above 80 %. These results clearly indicate that timing and magnitude of simulated discharge is correctly reproduced by the model. Additionally we assess the impact of the seasonality on the model parameterization yielding similar results in the discharge analysis. Our work shows that Kirchner's method can be applied successfully in the Ardèche catchment. Eventually, we observe that geology may be highlighted as a predictor that dominates the overall hydrological response in the basin. Kirchner, J. W. (2009), Catchments as simple dynamical systems: Catchment characterization, rainfall-runoff modeling, and doing hydrology backward, Water Resour. Res., 45, W02429, doi:10.1029/2008WR006912

  5. Basin Economic Allocation Model (BEAM): An economic model of water use developed for the Aral Sea Basin

    NASA Astrophysics Data System (ADS)

    Riegels, Niels; Kromann, Mikkel; Karup Pedersen, Jesper; Lindgaard-Jørgensen, Palle; Sokolov, Vadim; Sorokin, Anatoly

    2013-04-01

    The water resources of the Aral Sea basin are under increasing pressure, particularly from the conflict over whether hydropower or irrigation water use should take priority. The purpose of the BEAM model is to explore the impact of changes to water allocation and investments in water management infrastructure on the overall welfare of the Aral Sea basin. The BEAM model estimates welfare changes associated with changes to how water is allocated between the five countries in the basin (Kazakhstan, Kyrgyz Republic, Tajikistan, Turkmenistan and Uzbekistan; water use in Afghanistan is assumed to be fixed). Water is allocated according to economic optimization criteria; in other words, the BEAM model allocates water across time and space so that the economic welfare associated with water use is maximized. The model is programmed in GAMS. The model addresses the Aral Sea Basin as a whole - that is, the rivers Syr Darya, Amu Darya, Kashkadarya, and Zarafshan, as well as the Aral Sea. The model representation includes water resources, including 14 river sections, 6 terminal lakes, 28 reservoirs and 19 catchment runoff nodes, as well as land resources (i.e., irrigated croplands). The model covers 5 sectors: agriculture (crops: wheat, cotton, alfalfa, rice, fruit, vegetables and others), hydropower, nature, households and industry. The focus of the model is on welfare impacts associated with changes to water use in the agriculture and hydropower sectors. The model aims at addressing the following issues of relevance for economic management of water resources: • Physical efficiency (estimating how investments in irrigation efficiency affect economic welfare). • Economic efficiency (estimating how changes in how water is allocated affect welfare). • Equity (who will gain from changes in allocation of water from one sector to another and who will lose?). Stakeholders in the region have been involved in the development of the model, and about 10 national experts, including staff from the International Fund for Saving the Aral Sea (IFAS), have been trained in using the model. The model is publicly accessible through a web-based user interface that allows users to investigate scenarios and perform sensitivity analyses. Preliminary results suggest that: 1. At the margin, hydropower water use increases basin-wide welfare more than irrigation water use. 2. Under normal or average hydrological conditions, water scarcity is not a significant problem in the basin. 3. Under dry hydrological conditions, water scarcity is significant. Under these conditions, preliminary results suggest that cotton irrigation is less effective than other uses, particularly in Turkmenistan. 4. Investments in irrigation efficiency can have a significant impact on the effectiveness of water use for irrigation, thereby increasing the welfare of irrigation regions during dry periods.

  6. Characteristics of discrete and basin-centered parts of the Lower Silurian regional oil and gas accumulation, Appalachian basin; preliminary results from a data set of 25 oil and gas fields

    USGS Publications Warehouse

    Ryder, Robert T.

    1998-01-01

    Oil and gas trapped in Lower Silurian 'Clinton' sands and Medina Group sandstone constitute a regional hydrocarbon accumulation that extends 425 mi in length from Ontario, Canada to northeastern Kentucky. The 125-mi width of the accumulation extends from central Ohio eastward to western Pennsylvania and west-central New York. Lenticular and intertonguing reservoirs, a gradual eastward decrease in reservoir porosity and permeability, and poorly segregated gas, oil, and water in the reservoirs make it very difficult to recognize clear-cut geologic- and production-based subdivisions in the accumulation that are relevant to resource assessment. However, subtle variations are recognizable that permit the regional accumulation to be subdivided into three tentative parts: a western gas-bearing part having more or less discrete fields; an eastern gas-bearing part having many characteristics of a basin-centered accumulation; and a central oil- and gas-bearing part with 'hybrid' fields that share characteristics of both discrete and basin-centered accumulation. A data set of 25 oil and gas fields is used in the report to compare selected attributes of the three parts of the regional accumulation. A fourth part of the regional accumulation, not discussed here, is an eastern extension of basin-centered accumulation having local commercial gas in the Tuscarora Sandstone, a proximal facies of the Lower Silurian depositional system. A basin-centered gas accumulation is a regionally extensive and commonly very thick zone of gas saturation that occurs in low-permeability rocks in the central, deeper part of a sedimentary basin. Another commonly used term for this type of accumulation is deep-basin gas accumulation. Basin-centered accumulation is a variety of continuous-type accumulation. The 'Clinton' sands and Medina Group sandstone part of the basin-centered gas accumulation is characterized by: a) reservoir porosity ranging from about 5 to 10 percent; b) reservoir permeability equal to or less than 0.1 mD; c) low reservoir water saturation and an average water yield per well less than about 9 to 13 BW/MMCFG; d) a broadly defined updip water-block trap; e) underpressured reservoirs with a gradient ranging from 0.25 to 0.35 psi/ft; and f) reservoir temperature of at least 125? F (52? C). Other than for historical and location purposes, the term field has little or no meaning as an assessment unit for the regional accumulation. In practice, each designated field represents a production sweet spot having relatively high EURs per well that in turn merges with surrounding gas-productive regions that are generally larger in area but have lower EURs per well. This important feature of the Lower Silurian regional accumulation, whereby most wells drilled into it are gas productive, must be considered when assessing its potential for remaining recoverable gas resources. Most of the remaining gas resources reside in 'Clinton' sands and Medina Group sandstone in the basin-centered part of the accumulation where as much as several tens of TCF of natural gas may be technically recoverable. The Tuscarora Sandstone in the eastern extension of the basin-centered part of the accumulation underlies a very large area and, although commonly characterized by very low porosity and permeability and low-Btu gas, probably contains additional gas resources. Remaining undiscovered recoverable gas and oil resources in the discrete and hybrid parts of the accumulation are primarily located beneath Lake Erie.

  7. Multiscale investigations in a mesoscale catchment - hydrological modelling in the Gera catchment

    NASA Astrophysics Data System (ADS)

    Krause, P.; Bse, F.; Bende-Michl, U.; Fink, M.; Flgel, W.; Pfennig, B.

    2006-09-01

    The application of the hydrological process-oriented model J2000 (J2K) is part of a cooperation project between the Thuringian Environmental Agency (Thringer Landesanstalt fr Umwelt und Geologie - TLUG) and the Department of Geoinformatics of the Friedrich-Schiller-University Jena focussing on the implementation of the EU water framework directive (WFD). In the first project phase J2K was parametrised and calibrated for a mesoscale catchment to quantify if it can be used as hydrological part of a multi-objective tool-box needed for the implementation of the WFD. The main objectives for that pilot study were:

    1. The development and application of a suitable distribution concept which provide the spatial data basis for various tasks and which reflects the specific physiogeographical variability and heterogeneity of river basins adequately. This distribution concept should consider the following constraints: The absolute number of spatial entities, which forms the basis for any distributive modelling should be as small as possible, but the spatial distributed factors, which controls quantitative and qualitative hydrological processes should not be generalised to much. The distribution concept of hydrological response units HRUs (Flgel, 1995) was selected and enhanced by a topological routing scheme (Staudenrausch, 2001) for the simulation of lateral flow processes.
    2. J2K should be calibrated for one subbasin of the pilot watershed only. Then the parameter set should be used on the other subbasins (referred as transfer basins) to investigate and quantify the transferability of a calibrated model and potential spatial dependencies of its parameter set. In addition, potential structural problems in the process description should be identified by the transfer to basins which show a different process dominance as the one which was used for calibration does.
    3. Model calibration and selection of efficiency criteria for the quantification of the model quality should be based on a comprehensive sensitivity and uncertainty analysis (Bse, 2005) and multi-response validations with independent data sets (Krause and Flgel, 2005) carried out in advance in the headwater part of the calibration basin.
    4. To obtain good results in the transfer basins the calibrated parameter set could be adjusted slightly. This step was considered as necessary because of specific constraints which were not of significant importance in the calibration basin. This readjustment should be carried out on parameters which show a sensitive reaction on the identified differences in the environmental setup.
    5. Potential scaling problems of the process description, distribution concept or model structure should be identified by the comparison of the modelling results obtained in a small headwater region of the calibration basin with observed streamflow to find out if the selected efficiency measures show a significant change.

  8. Legacy Contaminantion in UK catchments since the mid-19th century

    NASA Astrophysics Data System (ADS)

    Howden, N. J. K.; Burt, T. P.; Worrall, F.; Noacco, V.; Wagener, T.

    2014-12-01

    We present data from UK catchments to characterise impacts of industrial and agricultural development of UK river catchments since the mid-19th century. We draw heavily on the world's longest continuous water quality monitoring programme in the Thames River Basin (1868-date) and discuss the implications of both agricultural development, social and industrial change, and the impact of legislation on coupled land and water resource systems. Our review draws on both data and model analysis over a 145-year period and explores how a multitude of inter-linked drivers affects process-function and practical water resource management decision-support. Our work uncovers key drivers, catchment responses and emergent challenges for process science and regulation, with particular emphasis on the technical challenge for catchment scientists to provide both insight and workable solutions to maintain food and water security in intensively management river basins. We discuss issues of appropriate methods for both data capture and subsequent analyses to support short- and long-term decision making, and particularly considers the importance of advanced techniques to clarify uncertainties in extrapolation of short-term observations to inform long-term goals. We speculate as to future trajectories of catchment responses to current pressures, and potential pitfalls to immediate concerns that may often be at odds with overall requirements for continued use of natural resources in the future.

  9. Modeling ground water flow in alluvial mountainous catchments on a watershed scale.

    PubMed

    Wolf, Jens; Barthel, Roland; Braun, Jrgen

    2008-01-01

    In large mountainous catchments, shallow unconfined alluvial aquifers play an important role in conveying subsurface runoff to the foreland. Their relatively small extent poses a serious problem for ground water flow models on the river basin scale. River basin scale models describing the entire water cycle are necessary in integrated water resources management and to study the impact of global climate change on ground water resources. Integrated regional-scale models must use a coarse, fixed discretization to keep computational demands low and to facilitate model coupling. This can lead to discrepancies between model discretization and the geometrical properties of natural systems. Here, an approach to overcome this discrepancy is discussed using the example of the German-Austrian Upper Danube catchment, where a coarse ground water flow model was developed using MODFLOW. The method developed uses a modified concept from a hydrological catchment drainage analysis in order to adapt the aquifer geometry such that it respects the numerical requirements of the chosen discretization, that is, the width and the thickness of cells as well as gradients and connectivity of the catchment. In order to show the efficiency of the developed method, it was tested and compared to a finely discretized ground water model of the Ammer subcatchment. The results of the analysis prove the applicability of the new approach and contribute to the idea of using physically based ground water models in large catchments. PMID:18459959

  10. Geological controls on isotopic signatures of streamflow: results from a nested catchment experiment in Luxembourg (Europe)

    NASA Astrophysics Data System (ADS)

    Pfister, Laurent; McDonnell, Jeffrey J.; Hissler, Christophe; Martinez-Carreras, Nuria; Gourdol, Laurent; Klaus, Julian; François Iffly, Jean; Barnich, François; Stewart, Mike K.

    2014-05-01

    Controls of geology and topography on hydrological metrics, like summer low flow (Grant and Tague, 2004) or dynamic storage (Sayama et al., 2011), have been identified in nested catchment experiments. However, most tracer-based studies on streamflow generation have been carried out in small (10 km2) homogenous catchments (Klaus and McDonnell, 2013). The controlling effects of catchment physiography on how catchments store and release water, and how this eventually controls stream isotope behaviour over a large range of scale are poorly understood. Here, we present results from a nested catchment analysis in the Alzette River basin (Luxembourg, Europe). Our hydro-climatological network consists of 16 recording streamgauges and 21 pluviographs. Catchment areas range from 0.47 to 285 km2, with clean and mixed combinations of distinct geologies ranging from schists to marls, sandstone, dolomite and limestone. Our objective was to identify geological controls on (i) winter runoff ratios, (ii) maximum storage and (iii) isotopic signatures in streamflow. For each catchment we determined average runoff ratios from winter season precipitation-discharge double-mass curves. Maximum catchment storage was based on the dynamic storage change approach of Sayama et al. (2011). Changes in isotopic signatures of streamflow were documented along individual catchment flow duration curves. We found strong correlations between average winter runoff ratios, maximum storage and the prevailing geological settings. Catchments with impermeable bedrock (e.g. marls or schists) were characterised by small storage potential and high average filling ratios. As a consequence, these catchments also exhibited the highest average runoff ratios. In catchments underlain by permeable bedrock (e.g. sandstone), storage potential was significantly higher and runoff ratios were considerably smaller. The isotopic signatures of streamflow showed large differences between catchments. In catchments dominated by permeable bedrock, isotopic signatures of streamflow remained stable throughout the entire flow duration curve consistent with a large storage and mixing potential. On less permeable bedrock substrate, we have observed that isotopic signatures in streamflow were much more variable, due to reduced storage volume and comparatively smaller mixing potential. Other metrics such as catchment size and flowpath length exerted a smaller secondary control on isotopic signatures of streamflow in the Alzette River sub-basins. Tague, C., Grant, G.E., 2004. A geological framework for interpreting the low-flow regimes of Cascade streams, Willamette River Basin, Oregon. Water Resources Research, 40(4), doi:10.1029/2003WR002629 Sayama, T., McDonnell, J.J., Dhakal, A., Sullivan, K., 2011. How much water can a watershed store ? Hydrological Processes 25, 3899-3908. Klaus, J., McDonnell, J.J., 2013. Hydrograph separation using stable isotopes: Review and evaluation. Journal of Hydrology 505, 47-64.

  11. Be-10 derived basin-wide erosion rates of Southern Qilian Shan, NE Tibet

    NASA Astrophysics Data System (ADS)

    Hu, K.; Fang, X.; Granger, D. E.; Zhao, Z.

    2013-12-01

    The actively uplifting Qilian Shan forms the northeastern margin of the Tibetan Plateau. The mountain range is bounded to the northeast by a thrust fault forming a 2 km-high mountain front over the Hexi Corridor basin, and to the southwest by a series of thrusts within an internally-drained elevated plateau that steps downwards into the Qaidam basin. The mountain range forms an important climatic boundary as well, where the East Asian Monsoon gives its way to Northern Hemisphere Westerlies. Understanding the interplay among active faulting, climate, and erosion in this region could be important for revealing the northeastern expansion and uplift of the Tibetan Plateau. Here we present 10Be derived catchment-wide erosion rates for a large area of the southern Qilian Shan. Our preliminary results show remarkably slow erosion rates ranging from~ 10 - 100 mm/ky,much slower than those reported for rivers draining the north Qilian Shan (ranging from 39-833 mm/ky) [Palumbo et al., 2011]. These results may suggest that catchments draining the mountain front experience relatively high precipitation and are eroding quickly, while catchments in the arid, internally-drained interior are isolated from base level fall and are eroding slowly. Moreover, our erosion rates may also suggest that the interior (southern) portions of the Qilian Shan are deforming more slowly than along the frontal thrust. This is consistent with the North Qilian Shan thrust accommodating most of the tectonic shortening in the mountain range, with shortening occurring at a slower rate in the interior. These data may suggest that low erosion rates (at least partially due to aridity) are promoting surface uplift of the Qilian Shan and Qaidam basin along the northeastern edge of the Tibetan Plateau. Additional samples are being processed from a variety of geologic and climatic settings that we hope will further elucidate patterns of erosion in the Qilian Shan region. Palumbo, L., R. Hetzel, M. Tao, and X. Li (2011), Catchment-wide denudation rates at the margin of NE Tibet from in situ-produced cosmogenic 10Be, Terra Nova, 23(1), 42-48.

  12. Applying different spatial distribution and modelling concepts in three nested mesoscale catchments of Germany

    NASA Astrophysics Data System (ADS)

    Bongartz, K.

    Distributed, physically based river basin models are receiving increasing importance in integrated water resources management (IWRM) in Germany and in Europe, especially after the release of the new European Water Framework Directive (WFD). Applications in mesoscale catchments require an appropriate approach to represent the spatial distribution of related catchment properties such as land use, soil physics and topography by utilizing techniques of remote sensing and GIS analyses. The challenge is to delineate scale independent homogeneous modelling entities which, on the one hand may represent the dynamics of the dominant hydrological processes and, on the other hand can be derived from spatially distributed physiographical catchment properties. This scaling problem is tackled in this regional modelling study by applying the concept of hydrological response units (HRUs). In a nested catchment approach three different modelling conceptualisations are used to describe the runoff processes: (i) the topographic stream-segment-based HRU delineation proposed by Leavesley et al. [Precipitation-Runoff-Modelling-System, Users Manual, Water Resource Investigations Report 83-4238, US Geological Survey, 1983]; (ii) the process based physiographic HRU-concept introduced by Flgel [Hydrol. Process. 9 (1995) 423] and (iii) an advanced HRU-concept adapted from (ii), which included the topographic topology of HRU-areas and the river network developed by Staudenraush [Eco Regio 8 (2000) 121]. The influence of different boundary conditions associated with changing the landuse classes, the temporal data resolution and the landuse scenarios were investigated. The mesoscale catchment of the river Ilm ( A?895 km 2) in Thuringia, Germany, and the Precipitation-Runoff-Modelling-System (PRMS) were selected for this study. Simulations show that the physiographic based concept is a reliable method for modelling basin dynamics in catchments up to 200 km 2 whereas in larger catchments, where lateral processes dominate, the other concepts have advantages.

  13. Map correlation method: Selection of a reference streamgage to estimate daily streamflow at ungaged catchments

    NASA Astrophysics Data System (ADS)

    Archfield, S. A.; Vogel, R. M.

    2010-10-01

    Daily streamflow time series are critical to a very broad range of hydrologic problems. Whereas daily streamflow time series are readily obtained from gaged catchments, streamflow information is commonly needed at catchments for which no measured streamflow information exists. At ungaged catchments, methods to estimate daily streamflow time series typically require the use of a reference streamgage, which transfers properties of the streamflow time series at a reference streamgage to the ungaged catchment. Therefore, the selection of a reference streamgage is one of the central challenges associated with estimation of daily streamflow at ungaged basins. The reference streamgage is typically selected by choosing the nearest streamgage; however, this paper shows that selection of the nearest streamgage does not provide a consistent selection criterion. We introduce a new method, termed the map-correlation method, which selects the reference streamgage whose daily streamflows are most correlated with an ungaged catchment. When applied to the estimation of daily streamflow at 28 streamgages across southern New England, daily streamflows estimated by a reference streamgage selected using the map-correlation method generally provides improved estimates of daily streamflow time series over streamflows estimated by the selection and use of the nearest streamgage. The map correlation method could have potential for many other applications including identifying redundancy and uniqueness in a streamgage network, calibration of rainfall runoff models at ungaged sites, as well as for use in catchment classification.

  14. Hydrological Response of Semi-arid Degraded Catchments in Tigray, Northern Ethiopia

    NASA Astrophysics Data System (ADS)

    Teka, Daniel; Van Wesemael, Bas; Vanacker, Veerle; Hallet, Vincent

    2013-04-01

    To address water scarcity in the arid and semi-arid part of developing countries, accurate estimation of surface runoff is an essential task. In semi-arid catchments runoff data are scarce and therefore runoff estimation using hydrological models becomes an alternative. This research was initiated in order to characterize runoff response of semi-arid catchments in Tigray, North Ethiopia to evaluate SCS-CN for various catchments. Ten sub-catchments were selected in different river basins and rainfall and runoff were measured with automatic hydro-monitoring equipments for 2-3 years. The Curve Number was estimated for each Hydrological Response Unit (HRU) in the sub-catchments and runoff was modeled using the SCS-CN method at ? = 0.05 and ? = 0.20. The result showed a significant difference between the two abstraction ratios (P =0.05, df = 1, n= 132) and reasonable good result was obtained for predicted runoff at ? = 0.05 (NSE = -0.69; PBIAS = 18.1%). When using the CN values from literature runoff was overestimated compared to the measured value (e= -11.53). This research showed the importance of using measured runoff data to characterize semi-arid catchments and accurately estimate the scarce water resource. Key words: Hydrological response, rainfall-runoff, degraded environments, semi-arid, Ethiopia, Tigray

  15. HYDROLOGIC SENSITIVITIES OF THE SACRAMENTO-SAN JOAQUIN RIVER BASIN, CA TO GLOBAL WARMING

    EPA Science Inventory

    The hydrologic sensitivities of four medium-sized mountainous catchments in the Sacramento and San Joaquin River basins to long-term global warming were analyzed. he hydrologic response of these catchments, all of which are dominated by spring snowmelt runoff, were simulated by t...

  16. Integration for sustainable catchment management.

    PubMed

    Macleod, Christopher J A; Scholefield, David; Haygarth, Philip M

    2007-02-15

    Sustainable catchment management requires increased levels of integration between groups of natural and social scientists, land and water users, land and water managers, planners and policy makers across spatial scales. Multiple policy drivers, covering urban and rural communities and their relationships with land and water use, have resulted in the need for an integrated decision making framework that operates from the strategic national scale to the local catchment scale. Large gaps in integration between policies are resulting in uncertain outcomes of conflicting and competing policy measures. The need for further integration is illustrated by little or no reductions in nitrate and phosphate levels in surface and ground waters in England and Wales. There is a requirement for natural scientists to consider the socio-economic setting and implications of their research. Moreover, catchment system level science requires natural and social scientists to work more closely, to provide robust analysis of the state of the environment that fully considers the bio-physical, social, political and economic settings. The combined use of spatial technologies, scenarios, indicators and multicriteria analysis are increasingly being used to enable improved integration for sustainable catchment management. PMID:17239423

  17. Preliminary results of organic geochemical and stable isotope analyses of Newark supergroup rocks in the Hartford and Newark basins, Eastern U.S.

    USGS Publications Warehouse

    Pratt, L.M.; Vuletich, A.K.; Shaw, C.A.

    1986-01-01

    Preliminary stage-discharge relations (limit curves) have been defined for Aliceville Lock and Dam covering the period February 1980 to May 1983 (Nelson and Ming, 1983). Subsequent data collected at the dam indicates a need for a revision to the preliminary curves. Due to channel instability in the vicinity, periodic review and possible update will be needed to keep the curves current. Using 48 data points defined by the flood of December 1983, the curves have been updated and are shown in this 1985 report. (USGS)

  18. Rainfall/runoff processes in a small peri-urban catchment in the Andes mountains. The Rumihurcu Quebrada, Quito (Ecuador)

    NASA Astrophysics Data System (ADS)

    Perrin, J. L.; Bouvier, C.; Janeau, J. L.; Mnez, G.; Cruz, F.

    2001-04-01

    Situated at the foot of the Pichincha volcano, the city of Quito is frequently subjected to hydroclimatic hazards. In 1995 an 112 km2 watershed, located in the vicinity of the city, was equipped with eight rain gauges and two flow gauges to better understand the local rainfall/runoff transformation processes. Rainfall simulation experiments were carried out on more than 40 one-square-metre plots to measure infiltration point-processes. The high density of measurement devices allowed us to identify the origin and nature of the various contributions to runoff for the different physiographic units of the watershed: urban area from an altitude of 2800 to 3200 m; farmland, pasture and forested land, and finally pramo above 3900 m. Runoff occurs mainly in the lower part of the basin and is caused by urbanization; however, the natural soils of this area can also produce Hortonian runoff, which is predominant in a few events. This contribution can be studied through rainfall simulation experiments. In the upper natural zone, the younger and more permeable soils generate less runoff on the slopes. However, almost permanently saturated contributing areas, which are located in the bottom of the quebradas, may generate flood events, the size of which depends on the extent of the area concerned. Variations in the runoff coefficients are related first to the baseflow and second to the amount of rainfall in the previous 24 h. This analysis, which underlines the complexity of a small, peri-urban, volcanic catchment, is a necessary preliminary to runoff modelling in an area where very few experiments have been carried out on small catchments.

  19. The influence of land use change on landslide susceptibility zonation: the Briga catchment test site (Messina, Italy)

    NASA Astrophysics Data System (ADS)

    Reichenbach, Paola; Busca, Claudia; Mondini, Alessandro; Rossi, Mauro

    2013-04-01

    Landslides spatial distribution and frequency are the consequence of different meteorological conditions, the land use and environmental settings including topographical, morphological, hydrological, lithology. Lithology and structure change over periods of millions of years, morphology varies rapidly or over a period of centuries if mass wasting processes are consistent, climate, and land use change seasonally or over a period of decades. In this work we have attempted to evaluate the influence of land use change in a period of about 60 years on landslide spatial distribution occurrence (susceptibility) for the Briga catchment test site. The Briga basin is located along the Ionian coast of Sicily (SW of Messina, Italy). On 1 October 2009, the area was hit by a high intensity rainfall event that triggered abundant slope failures, and resulted in widespread erosion and deposition of debris along ephemeral drainage channels. After the storm, an accurate event landslide inventory map was made for the catchment and a pre-event landslide map was prepared using aerial photographs. For the test area two different land use maps were realized. The first was obtained through a semi-automatic classification of a digitized aerial photographs acquired during the year 1954, the second through the combination of supervised classifications of two QuickBird images acquired in 2006 and 2009. Exploiting the two different land use maps, different susceptibility zonations were prepared through a multivariate statistical analysis of a set of morphological and land use information. Differences in the susceptibility models were analyzed to identify: i) land use change effects on the landslide susceptibility; ii) the influence of human action on the land use change and iii) the consequences of land use change on landslide vulnerability and risk. Preliminary results show an overall increase of the susceptibility, probably due to the increase of bare soil to the detriment of forested areas, mainly in correspondence of pre-existing and new urban areas.

  20. Sediment sources and its transport pathways in the Kharaa catchment, northern Mongolia

    NASA Astrophysics Data System (ADS)

    Theuring, P.; Rode, M.

    2012-04-01

    Soil erosion and its subsequent transport towards and within rivers is complex, dependent on many catchment properties, hydrology and land use. However, little is known about the sources and fate of suspended sediment (SS) in the 15.000km2 Kharaa study catchment in Mongolia. This study focuses therefore on a qualitative identification of sediment sources and the quantification of the suspended sediment transport in the catchment. Geochemical sediment source fingerprinting in combination with isotope fingerprinting is used to identify and localize the most important sediment source areas in the catchment and assess their contribution to the suspended sediment load. More than 1000 grab samples from 22 river junctions of the outlet of each sub basin into the main tributary were taken in the period from 2009 to 2011. Their fine sediment fractions (<10?m) have been analysed for major elements (e.g. Si, Al, Mg) and trace elements (e.g. Ba, Pb, Sr,) using ICP-MS. The contribution of each sub basin to the SS in the main tributary has then been calculated using mixing model analysis. Additionally, isotope fingerprinting was used to assess the importance and contribution of surface, stream bank and gully erosion on total sediment load of the catchment. Biannual samples of 12 topsoil eroding surface reference sites, 4 stream banks and 4 suspended sediment samples were analysed for the atmospheric fallout radionuclides Cs-137, Pb-210 and Be-7 using gamma ray spectrometry. The sediment budget of the catchment was calculated with the help of the regional catchment scale sediment budget model (SedNet. Results suggest that only a small part of the catchment contributes considerably to the total sediment load and that gully and bank erosion might be the dominating sources in the catchment that lead to fine sediment intrusion and ecosystem degradation in the riverbed in the midstream regions. Also there seems to be a difference in erosion behaviour between spring and fall, with a higher contribution from surface erosion during summer rainfall. Future work will concentrate on scenario analysis modelling of the sediment transport in the catchment with HYPE as well as uncertainty analysis of the model.

  1. Flowpaths, source water contributions and water residence times in a Mexican tropical dry forest catchment

    NASA Astrophysics Data System (ADS)

    Farrick, Kegan K.; Branfireun, Brian A.

    2015-10-01

    Runoff in forested tropical catchments has been frequently described in the literature as dominated by the rapid translation of rainfall to runoff through surface and shallow subsurface pathways. However, studies examining runoff generation in tropical catchments with highly permeable soils have received little attention, particularly in tropical dry forests. We present a study focused on identifying the dominant flowpaths, water sources and stream water residence times in a tropical dry forest catchment near the Pacific coast of central Mexico. During the wet season, pre-event water contributions to stormflow ranged from 72% to 97%, with the concentrations of calcium, magnesium, sodium and potassium closely coupling the geochemistry of baseflow and groundwater from the narrow riparian/near-stream zone. Baseflow from the intermittent stream showed a strongly damped isotopic signature and a mean baseflow residence time of 52-110 days was estimated. These findings all suggest that instead of the surface and near-surface subsurface lateral pathways observed over many tropical catchments, runoff is generated through vertical flow processes and the displacement and discharge of stored water from the saturated zone. As the wet season progressed, contributions from the saturated zone persisted; however, the stormflow and baseflow geochemistry suggests that the contributing area of the catchment increased. Our results show that during the early part of the wet season, runoff originated primarily from the headwater portion of the catchment. As the wet season progressed and catchment wetness increased, connectivity among sub-basin was improved, resulting in runoff contributions from across the entire catchment.

  2. Runoff and Solute Mobilisation in a Semi-arid Headwater Catchment

    NASA Astrophysics Data System (ADS)

    Hughes, J. D.; Khan, S.; Crosbie, R.; Helliwell, S.; Michalk, D.

    2006-12-01

    Runoff and solute transport processes contributing to stream flow were determined in a small headwater catchment in the eastern Murray-Darling Basin of Australia using hydrometric and tracer methods. Stream flow and electrical conductivity were monitored from two gauges draining a portion of upper catchment area (UCA), and a saline scalded area respectively. Results show that the bulk of catchment solute export, occurs via a small saline scald (< 2% of catchment area) where solutes are concentrated in the near surface zone (0-40 cm). Non-scalded areas of the catchment are likely to provide the bulk of catchment runoff, although the scalded area is a higher contributor on an areal basis. Runoff from the non-scalded area is about two orders of magnitude lower in electrical conductivity than the scalded area. This study shows that the scalded zone and non-scalded parts of the catchment can be managed separately since they are effectively de-coupled except over long time scales, and produce runoff of contrasting quality. Such differences are "averaged out" by investigations that operate at larger scales, illustrating that observations need to be conducted at a range of scales. EMMA modelling using six solutes shows that "event" or "new" water dominated the stream hydrograph from the scald. This information together with hydrometric data and soil physical properties indicate that saturated overland flow is the main form of runoff generation in both the scalded area and the UCA. Saturated areas make up a small proportion of the catchment, but are responsible for production of all run off in conditions experienced throughout the experimental period. The process of saturation and runoff bears some similarities to the VSA concept (Hewlett and Hibbert 1967).

  3. Quantifying Spatial Variability in Runoff Quality in Semi-arid Urban Catchments

    NASA Astrophysics Data System (ADS)

    Peterson, A. M.; Gallo, E. L.; Lohse, K. A.; Brooks, P. D.; Meixner, T.

    2010-12-01

    Urbanization alters ecosystem function and subsequently impacts quantity and quality of stormwater runoff. In arid and semi-arid urban ecosystems, solutes may accumulate in upland environments for several months between rainfall events, which flush these potential pollutants to stream channels. Although this decline in water quality is well documented with urbanization, it is unclear how different urbanization intensities affect catchment hydrologic responses and N dynamics in semi-arid regions. We expected that N would decline with increasing impervious cover. In heavily urbanized watersheds, N delivery would be controlled primarily by hydrologic transport and would exhibit a conservative flushing response. In watersheds with a lower density of development, N delivery would be related to complex source-sink relationships and would not exhibit a conservative flushing response. To address these hypotheses, we collected rainfall and stormwater runoff samples from 22 catchments in Tucson AZ that vary in percent impervious cover (IC, 2.92% to 90.7%) and catchment area (0.33km2 to 28.48km2.) We used a combination of 22 single-stage siphon samplers; one per catchment, paired with six multiple-stage automatic water collectors in a subset of catchments, to efficiently and inexpensively collect runoff samples across a wide these gradients of urbanization. There is a strong (r2 = 0.79) and significant (p < 0.05) correlation between the auto sampler and siphon sampler runoff quality. We found that pH and EC do not vary with catchment area, suggesting that the entire catchment may not be contributing surface runoff and solutes to streamflow. However, EC significantly increases with IC, while pH significantly decreases with IC. Data suggest that at high IC, pH of runoff begins to approximate the pH of rainfall (6.75). Given that urban catchments are designed to efficiently route runoff into waterways, it is plausible the increased IC results in more efficient mobilization of solutes, in a shorter time range, which may explain why pH begins to approximate rainfall at higher IC. We observe a significant decrease in EC over the monsoon (July to Sept) while at the same time observing a significant increase in pH, which may be the result of seasonal solute flushing. Preliminary data show that NH4-N does not vary with IC and catchment area, while PO4-P appears to decrease with catchment size and increase with IC, suggesting that some runoff solutes more directly impacted by land cover and biogeochemical catchment processes. Findings from our study suggest that imperviousness and seasonal dynamics impart a greater control on runoff quality than catchment size.

  4. Will urban expansion lead to an increase in future water pollution loads?--a preliminary investigation of the Haihe River Basin in northeastern China.

    PubMed

    Dong, Yang; Liu, Yi; Chen, Jining

    2014-01-01

    Urban expansion is a major driving force changing regional hydrology and nonpoint source pollution. The Haihe River Basin, the political, economic, and cultural center of northeastern China, has undergone rapid urbanization in recent decades. To investigate the consequences of future urban sprawl on nonpoint source water pollutant emissions in the river basin, the urban sprawl in 2030 was estimated, and the annual runoff and nonpoint source pollution in the Haihe River basin were simulated. The Integrated Model of Non-Point Sources Pollution Processes (IMPULSE) was used to simulate the effects of urban sprawl on nonpoint source pollution emissions. The outcomes indicated that the urban expansion through 2030 increased the nonpoint source total nitrogen (TN), total phosphorous (TP), and chemical oxygen demand (COD) emissions by 8.08, 0.14, and 149.57 kg/km(2), respectively. Compared to 2008, the total nonpoint emissions rose by 15.33, 0.57, and 12.39 %, respectively. Twelve percent of the 25 cities in the basin would increase by more than 50 % in nonpoint source TN and COD emissions in 2030. In particular, the nonpoint source TN emissions in Xinxiang, Jiaozuo, and Puyang would rise by 73.31, 67.25, and 58.61 %, and the nonpoint source COD emissions in these cities would rise by 74.02, 51.99, and 53.27 %, respectively. The point source pollution emissions in 2008 and 2030 were also estimated to explore the effects of urban sprawl on total water pollution loads. Urban sprawl through 2030 would bring significant structural changes of total TN, TP, and COD emissions for each city in the area. The results of this study could provide insights into the effects of urbanization in the study area and the methods could help to recognize the role that future urban sprawl plays in the total water pollution loads in the water quality management process. PMID:24532209

  5. Preliminary analyses of matrix properties of Silurian and Devonian carbonate rocks in the Indiana and Ohio parts of the Midwestern Basins and Arches Region

    SciTech Connect

    Casey, G.D. . Water Resources Div.)

    1994-04-01

    The US Geological Survey's Regional Aquifer-Systems Analysis (RASA) in the Midwestern Basins and Arches Region is investigating the Silurian and Devonian carbonate-rock aquifer in parts of Indiana, Ohio, Michigan, and Illinois. Core samples from the carbonate-rock aquifer in Indiana and Ohio were analyzed for horizontal permeability and porosity. These matrix properties were used to describe the hydrogeologic aspects of the carbonate-rock aquifer throughout the regional study area. Core descriptions by the Indiana and Ohio State Geological surveys, were used for sub-dividing the core into the various lithostratigraphic groups. The lithostratigraphic groups are: the Brassfield/Sexton Creek Limestone, the Sublockport (including the Dayton Limestone and the Rochester Shale Equivalent), the Lockport Dolomite or the Salamonie Dolomite, the Salina Group, the lower section of the Muscatatuck Group and the upper section of the Muscatatuck Group. The porosities and horizontal permeabilities determined from the 38 samples were analyzed by nonparametric statistical methods. The data were grouped by lithologic unit, well location, and position within a depositional basin (the Appalachian, Michigan and Illinois Basins). In each case, all groups of data had identical distributions. These results show that the horizontal permeability and porosity of the matrix in the Silurian and Devonian carbonate rocks that were sampled are statistically similar and that variation between the groups is not statistically important.

  6. Hydrogeomorphic paradigm of stormflow generation in headwater catchments

    NASA Astrophysics Data System (ADS)

    Sidle, Roy C.

    2015-04-01

    Over the past century, different paradigms have emerged to explain the processes of stormflow generation in steep, vegetated headwater catchments. These headwaters are important source areas of flood waters, sediments, nutrients, and biota that affect larger basins and coastal waters. Headwater systems exhibit unique and complex hydrogeomorphic processes from hillslopes to stream channels as well as linkages to downstream reaches. Through the 1960's, stormflow generation was largely attributed to Hortonian overland flow mechanisms. While numerous studies indicated the significance of saturated and unsaturated subsurface flow, it was not until the mid-1960's that the variable source area concept of streamflow generation emerged invoking a dynamic riparian source area that shrinks and expands in response to precipitation and fluctuating water tables. However, this concept does not specify flow mechanisms or pathways functioning at different spatial scales within the catchment. Based on extensive studies in nested, headwater catchment components in Japan, a conceptual hydrogeomorphic model has been developed to more explicitly explain stormflow pathways and response. The conceptual model recognizes the close coupling of hillslope and channel hydrological processes and the unique contributions of geomorphic features such as riparian corridors, geomorphic hollows, and linear hillslopes. During the driest conditions, catchment water yield is very low and runoff occurs as saturated overland flow from the narrow riparian corridors and via direct channel interception. For slightly wetter conditions, subsurface flow from the soil matrix augments stormflow. As wetness increases, two significant non-linear hydrologic responses occur: (1) response from geomorphic hollows (zero-order basins) after a threshold of shallow groundwater accumulates; and (2) self-organization and expansion of preferential flow pathways that facilitate significant amounts of subsurface drainage. The temporal responses from these distinct but linked geomorphic components network forms the basis for the hydrogeomorphic concept of stormflow generation. A parsimonious model has been developed that simulates storm discharge from channel-riparian complexes using a kinematic wave algorithm and from geomorphic hollows (zero-order basins) and hillslopes using a multitank model. Simulations were in good agreement with runoff measurements.

  7. Sediment connectivity evolution on an alpine catchment undergoing glacier retreat

    NASA Astrophysics Data System (ADS)

    Goldin, Beatrice; Rudaz, Benjamin; Bardou, Eric

    2014-05-01

    Climate changes can result in a wide range of variations of natural environment including retreating glaciers. Melting from glaciers will have a significant impact on the sediment transport characteristics of glacierized alpine catchments that can affect downstream channel network. Sediment connectivity assessment, i.e. the degree of connections that controls sediment fluxes between different segments of a landscape, can be useful in order to address management activity on sediment fluxes changes of alpine streams. Through the spatial characterization of the connectivity patterns of a catchment and its potential evolution it is possible to both define sediment transport pathways and estimate different contributions of the sub-catchment as sediment sources. In this study, a topography based index (Cavalli et al., 2013) has been applied to assess spatial sediment connectivity in the Navisence catchment (35 km2), an alpine basin located in the southern Walliser Alps (Switzerland) characterized by a complex glacier system with well-developed lateral moraines on glacier margins already crossed by several lateral channels. Glacier retreat of the main glacial edifice will provide a new connectivity pattern. At present the glacier disconnects lateral slopes from the main talweg: it is expected that its retreat will experience an increased connectivity. In order to study this evolution, two high resolution (2 m) digital terrain models (DTMs) describing respectively the terrain before and after glacier retreat have been analyzed. The current DTM was obtained from high resolution photogrammetry (2 m resolution). The future DTM was derived from application of the sloping local base level (SLBL) routine (Jaboyedoff et al., 2004) on the current glacier system, allowing to remove the ice body by reconstituting a U-shaped polynomial bedrock surface. From this new surface a coherent river network was drawn and slight random noise was added. Finally the river network was burned into the rough surface of the SLBL results. The impact of sediment dynamic changes on the study catchment due to glacier retreat has been assessed by comparing predictions deriving from model application on different scenarios. Simulations allowed the analysis of sediment connectivity evolution over decade scales suggesting an increase of potential sediment transfer and connections in areas close to the main channel network. References: Cavalli, M., Trevisani, S., Comiti, F., Marchi, L., 2013. Geomorphometric assessment of spatial sediment connectivity in small Alpine catchments. Geomorphology 188, 31-41. Jaboyedoff M., Bardou E., Derron M.-H. 2004. Sloping local base level: a tool to estimate potential erodible volume and infilling alluvial sediment of glacial valleys. Swiss Geo-Scientists meeting, November 2004, Lausanne.

  8. Factors controlling mercury transport in an upland forested catchment

    USGS Publications Warehouse

    Scherbatskoy, T.; Shanley, J.B.; Keeler, G.J.

    1998-01-01

    Total mercury (Hg) deposition and input/output relationships were investigated in an 11-ha deciduous forested catchment in northern Vermont as part of ongoing evaluations of rig cycling and transport in the Lake Champlain basin. Atmospheric Hg deposition (precipitation + modeled vapor phase downward flux) was 425 mg ha-1 during the one-year period March 1994 through February 1995 and 463 mg ha-1 from March 1995 through February 1996. In the same periods, stream export of total Hg was 32 mg ha-1 and 22 mg ha-1, respectively. Thus, there was a net retention of Hg by the catchment of 92% the first year and 95% the second year. In the first year, 16.9 mg ha-1 or about half of the annual stream export, occurred on the single day of peak spring snowmelt in April. In contrast, the maximum daily export in the second year, when peak stream flow was somewhat lower, was 3.5 mg ha-1 during a January thaw. The fate of file Hg retained by this forested catchment is not known. Dissolved (< 0.22 ??m) Hg concentrations in stream water ranged from 0.5-2.6 ng L-1, even when total (unfiltered) concentrations were greater than 10 ng L-1 during high flow events. Total Hg concentrations in stream water were correlated with the total organic fraction of suspended sediment, suggesting the importance of organic material in Hg transport within the catchment. High flow events and transport with organic material may be especially important mechanisms for the movement of Hg through forested ecosystems.

  9. Creating a catchment scale perspective for river restoration

    NASA Astrophysics Data System (ADS)

    Benda, L.; Miller, D.; Barqun, J.

    2011-09-01

    One of the major challenges in river restoration is to identify the natural fluvial landscape in catchments with a long history of river control. Intensive land use on valley floors often predates the earliest remote sensing: levees, dikes, dams, and other structures alter valley-floor morphology, river channels and flow regimes. Consequently, morphological patterns indicative of the fluvial landscape including multiple channels, extensive floodplains, wetlands, and fluvial-riparian and tributary-confluence dynamics can be obscured, and information to develop appropriate and cost effective river restoration strategies can be unavailable. This is the case in the Pas River catchment in northern Spain (650 km2), in which land use and development have obscured the natural fluvial landscape in many parts of the basin. To address this issue we used computer tools to examine the spatial patterns of fluvial landscapes that are associated with five domains of hydro-geomorphic processes and landforms. Using a 5-m digital elevation model, valley-floor surfaces were mapped according to elevation above the channel and proximity to key geomorphic processes. The predicted fluvial landscape is patchily distributed according to hillslope and valley topography, river network structure, and channel elevation profiles. The vast majority of the fluvial landscape in the main segments of the Pas River catchment is presently masked by human infrastructure, with only 15% not impacted by river control structures and development. The reconstructed fluvial landscape provides a catchment scale context to support restoration planning, in which areas of potential ecological productivity and diversity could be targeted for in-channel, floodplain and riparian restoration projects.

  10. Bayesian Uncertainty of Thwaites Glacier Catchment Radar Stratigraphy

    NASA Astrophysics Data System (ADS)

    Gutowski, G.; Jackson, C. S.; Blankenship, D. D.; Young, D. A.; Cavitte, M. G.

    2013-12-01

    Information about the history and dynamics of ice sheets is contained in basin-scale radar sounding surveys. Englacial, isochronous radar horizons traced throughout the sampled domain of these basins can give a three-dimensional picture of past ice flow by revealing significant details of deformation within the ice column. We focus our efforts in the Thwaites Glacier catchment, West Antarctica, which previous studies have shown to be a bellwether in future WAIS deglaciation scenarios. Here we present a Bayesian determination of the age-depth profile at the Byrd ice core, Antarctica, based on robust uncertainty estimates in ice core ages and radar sounding depths. A simple ice flow model is used to determine the age-depth relationship in ice near the core and a Markov Chain Monte Carlo technique is used to sample a posterior distribution of age as a function of depth to within uncertainty. We propagate the age-depth information, including uncertainty, for several prominent radar reflectors from the Byrd ice-coring site in the Interior Ross Embayment across the ice divide and throughout the Thwaites Glacier catchment using airborne ice-penetrating radar data collected and processed by the University of Texas Institute for Geophysics.

  11. Where is the Total Nitrogen accumulating in the Thames catchment (UK)?

    NASA Astrophysics Data System (ADS)

    Noacco, V.; Howden, N. J.; Wagener, T.; Pianosi, F.; Worrall, F.; Burt, T. P.

    2013-12-01

    The Thames basin has been shown to be a net sink of reactive nitrogen (N) since the 1940s, but it is still unresolved where this N is accumulating. This crucial question has to be addressed before we can understand the capacity of the catchment system to remove or attenuate nutrient export, and therefore future prospects for water quality in the Thames basin. For this purpose, we estimate the total annual nitrogen and carbon budgets of the Thames basin from 1867 to 2007 using budgeting models. The potential N sinks considered, i.e. possible locations for N to accumulate, are the terrestrial biosphere as land not currently used for food production, the sub-soil and the unsaturated zone of aquifers. The carbon model estimates soil organic carbon (SOC) stocks for typical land-uses in the Thames basin. The relationship between carbon and nitrogen, expressed by the C:N ratio typical of soils in the Thames catchment, allows to link the carbon and nitrogen stocks. We use global variance-based Sensitivity Analysis to understand the robustness of our conclusions. Thus considering the uncertainty in both the model parameters and the inputs to identify the factors most responsible for the uncertainty in the model output. We find that the accumulated N is likely stored in the sub-soil. A finding that is backed up by the results from the carbon model, which suggests that the Thames catchment is also a net carbon sink.

  12. What happens when catchments get excited? Exploring the link between hydrologic states and responses across spatial scales

    NASA Astrophysics Data System (ADS)

    Wrede, S.; Lyon, S. W.; Martinez-Carreras, N.; Pfister, L.; Uhlenbrook, S.

    2010-12-01

    Investigating relationships between dynamic hydrologic states and associated hydrologic responses of catchments is essential for a better understanding and conceptualization of hydrologic functioning and classification across spatial scales. Nevertheless, the question of What happens when catchments get excited? still remains unanswered for most catchments to date. This is especially true with regard to underlying landscape controls and how their relative importance can shift given the state of the various storages in a catchment. To help answering this question, we combined hydrometric and tracer approaches with landscape analysis in 24 nested catchments in Luxembourg, Europe with contrasting bedrock geology ranging from 0.5 to 1091 km2. In our study we discerned two major hydrological states (dry and wet) for each basin according to slope changes in double mass curves of cumulated discharge and precipitation. For each of these states the long-term (i.e. interannual) response of catchment behavior was characterized using conventional runoff signatures, such as master recession curves and average lag time between rainfall and runoff response. We found significantly different hydrologic responses for different hydrologic states of the catchments. These are typified by faster flow recessions, but longer average lag times during wet states and slower flow recessions, but shorter lag times during dry states. Dominating landscape controls on hydrological responses differed during these distinct hydrologic states and were identified as variables related to geology (percentage of impervious bedrock area) and soils (average soil depth), indicating different controls on hydrologic processes under different hydrologic states. Clustering of biweekly conductivity and silica stream water concentration data of the catchments further illustrated the dominant control of the geology on stream chemistry and revealed similar patterns during different hydrologic states. Our findings demonstrate that hydrologic response and their associated controls are closely linked to the dynamic hydrologic states of the catchments and hence should not be neglected in catchment modeling and classification approaches.

  13. Analyzing runoff processes through conceptual hydrological modeling in the Upper Blue Nile Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Dessie, M.; Verhoest, N. E. C.; Pauwels, V. R. N.; Admasu, T.; Poesen, J.; Adgo, E.; Deckers, J.; Nyssen, J.

    2014-12-01

    Understanding runoff processes in a basin is of paramount importance for the effective planning and management of water resources, in particular in data-scarce regions such as the Upper Blue Nile. Hydrological models representing the underlying hydrological processes can predict river discharges from ungauged catchments and allow for an understanding of the rainfall-runoff processes in those catchments. In this paper, such a conceptual process-based hydrological model is developed and applied to the upper Gumara and Gilgel Abay catchments (both located within the Upper Blue Nile Basin, the Lake Tana sub-basin) to study the runoff mechanisms and rainfall-runoff processes in the basin. Topography is considered as a proxy for the variability of most of the catchment characteristics. We divided the catchments into different runoff production areas using topographic criteria. Impermeable surfaces (rock outcrops and hard soil pans, common in the Upper Blue Nile Basin) were considered separately in the conceptual model. Based on model results, it can be inferred that about 65% of the runoff appears in the form of interflow in the Gumara study catchment, and baseflow constitutes the larger proportion of runoff (44-48%) in the Gilgel Abay catchment. Direct runoff represents a smaller fraction of the runoff in both catchments (18-19% for the Gumara, and 20% for the Gilgel Abay) and most of this direct runoff is generated through infiltration excess runoff mechanism from the impermeable rocks or hard soil pans. The study reveals that the hillslopes are recharge areas (sources of interflow and deep percolation) and direct runoff as saturated excess flow prevails from the flat slope areas. Overall, the model study suggests that identifying the catchments into different runoff production areas based on topography and including the impermeable rocky areas separately in the modeling process mimics the rainfall-runoff process in the Upper Blue Nile Basin well and yields a useful result for operational management of water resources in this data-scarce region.

  14. Analyzing runoff processes through conceptual hydrological modelling in the Upper Blue Nile basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Dessie, M.; Verhoest, N. E. C.; Pauwels, V. R. N.; Admasu, T.; Poesen, J.; Adgo, E.; Deckers, J.; Nyssen, J.

    2014-05-01

    Understanding runoff processes in a basin is of paramount importance for the effective planning and management of water resources, in particular in data scarce regions of the Upper Blue Nile. Hydrological models representing the underlying hydrological processes can predict river discharges from ungauged catchments and allow for an understanding of the rainfall-runoff processes in those catchments. In this paper, such a conceptual process-based hydrological model is developed and applied to the upper Gumara and Gilgel Abay catchments (both located within the Upper Blue Nile basin, the Lake Tana sub-basin) to study the runoff mechanisms and rainfall-runoff processes in the basin. Topography is considered as a proxy for the variability of most of the catchment characteristics. We divided the catchments into different runoff production areas using topographic criteria. Impermeable surfaces (rock outcrops and hard soil pans, common in the Upper Blue Nile basin) were considered separately in the conceptual model. Based on model results, it can be inferred that about 65% of the runoff appears in the form of interflow in the Gumara study catchment, and baseflow constitutes the larger proportion of runoff (44-48%) in the Gilgel Abay catchment. Direct runoff represents a smaller fraction of the runoff in both catchments (18-19% for the Gumara, and 20% for the Gilgel Abay) and most of this direct runoff is generated through infiltration excess runoff mechanism from the impermeable rocks or hard soil pans. The study reveals that the hillslopes are recharge areas (sources of interflow and deep percolation) and direct runoff as saturated excess flow prevails from the flat slope areas. Overall, the model study suggests that identifying the catchments into different runoff production areas based on topography and including the impermeable rocky areas separately in the modeling process mimics well the rainfall-runoff process in the Upper Blue Nile basin and brings a useful result for operational management of water resources in this data scarce region.

  15. Preliminary study of land-plant biomarkers in marine sediments of Alfonso basin and its relationship with the climate of the last 3.5 ka

    NASA Astrophysics Data System (ADS)

    Ricaurte-Villota, Constanza; Gonzalez-Yajimovich, Oscar; Betancourt-Portela, Julian

    2014-05-01

    This study used biomarkers such as n-alkanes, especially focused on the long chain n-alkanes and some diagnostic indexes derived from abundance, to elucidate molecular changes in the contribution of organic matter to the sediments, especially terrestrial vegetation surrounding continental areas around of Alfonso basin in response to climate change, particularly changes in the hydrological cycle. The results show that in general the n-alkanes of organic matter (OM) of Alfonso basin sediments are composed of a mixture of waxes derived from phytoplankton and terrestrial plants, with a greater contribution from phytoplankton compare to terrestrial vegetation, in the oldest part of the record, associated with a marine productivity increased period favored by rainfall. Maximum abundance of C29, and high values of C27/C31 ratio indicate leaves from trees as a source wax, probably succulents plants characteristic of arid zones, with C3 as one of their metabolic pathway, identified from mean ACL values around 29.5. The low CPI index indicates contamination and microbial communities as a possible source of long chain n-alkanes, probably due to anoxic bottom conditions in Alfonso basin favor the development of these communities. Finally, it is suggested no change in the community, at least for the last ~ 3.5 ka BP, but increased cover vegetation (biomass) in southern California during periods of increased rainfall (from ~ 3.5 to ~ 1.7 ka BP). The ability of terrestrial plant communities to adapt for longer periods before being replaced by other species, when faced with gradual changes rather than rapid climate change is reflected in a few changes in its composition.

  16. Preliminary hydrogeologic framework of the Silurian and Devonian carbonate aquifer system in the Midwestern Basins and Arches Region of Indiana, Ohio, Michigan, and Illinois

    SciTech Connect

    Casey, G.D. )

    1992-01-01

    The aquifer and confining units have been identified; data on the thickness, extent, and structural configuration of these units have been collected; and thickness and structure-contour maps have been generated. Hydrologic information for the confining units and the aquifer also has been compiled. Where present, the confining unit that caps the carbonate aquifer consists of shales of Middle and Upper Devonian age and Lower Mississippian age, however, these units have been eroded from a large part of the study area. The regional carbonate aquifer consists of Silurian and Devonian limestones and dolomites. The rocks that comprise the aquifer in Indiana and northwestern Illinois are grouped into four major stratigraphic units: Brassfield and Sexton Creek Limestones or the Cataract Formation, the Salamonie Dolomite, the Salina Group, and the Detroit River and Traverse Formations or the Muscatatuck Group. In Ohio and southern Michigan the aquifer is grouped into ten stratigraphic units: Brassfield Limestone and Cataract Formation, the Dayton Limestone, the Rochester Shale equivalent, the Lockport Dolomite, the Salina Formation, the Hillsboro Sandstone, the Detroit River Group, the Columbus Limestone, the Delaware Limestone, and the Traverse Formation. The thickness of the carbonate aquifer increases from the contact with the outcropping Ordovician shales in the south-central part of the study area from the contact into the Appalachian Foreland Structural Basin from 0 ft at the contact to more than 700 ft at the eastern boundary of the study area, to more than 1,000 ft beneath Lake Erie and greater than 1,200 ft in southeastern Michigan. At the edge of the Michigan Intercontinental Structural Basin in western Ohio and eastern Indiana, the thickness ranges from 700 to 900 ft. and from 200 ft to 300 ft in south-central Indiana along the northeastern edge of the Illinois Intercontinental Structural Basin.

  17. A modern analog of past climatic impacts on sedimentary processes and landscape evolution in an intermontane basin: The Del Medio fan, NW Argentina

    NASA Astrophysics Data System (ADS)

    Savi, Sara; Schildgen, Taylor F.; Tofelde, Stefanie; Wittmann, Hella; Strecker, Manfred

    2014-05-01

    The combined effects of tectonic and climatic forcing govern the evolution of landscapes, setting the scale of topographic relief and the pace of landscape changes over time. Tectonic uplift or changes in precipitation regimes can fundamentally modify erosional processes and sediment flux from hillslopes, change river profiles, and ultimately impact depositional systems downstream. The complexity of the response, however, often means that we cannot predict a priori how a given landscape will react to future changes in climate, or how it responded in the past to multiple episodes of climate change. The Del Medio catchment is located in the southern part of the Humahuaca Basin, an intermontane valley within the Eastern Cordillera in transition to the Puna Plateau. This area coincides with a climatic and vegetation divide between a sub-humid environment downstream and the semi-arid upper Humahuaca Basin. An extensive fan sourced in the Del Medio catchment covers ca. 18.6 km2 of the basin outlet. The fan stratigraphy and surface morphology suggest that the fan dynamics are dominated by debris-flow processes. The surface comprises abandoned channels, levees and lobes, while exposed sections in channel cuts reveal unsorted, matrix-dominated deposits, with individual boulders reaching a diameter of 5 m. To investigate rates and timing of the Del Medio fan evolution, we analyzed cosmogenic 10Be concentrations on the surfaces of large boulders from the fan surface, river sands in active channels, a depth profile, and bedrock exposed atop the drainage basin margins. Our preliminary CRN results illustrate the rapid rate at which the active fan surface is subject to change, with each of the 11 analyzed boulder samples providing ages of < 200 years. In addition, river sands record very high denudation rates that range from several mm/yr to tens of mm/yr, despite bedrock denudation rates from the basin margins of only 0.04 mm/yr. These contrasting denudation rates likely result from frequent landsliding and debris flows along the steep slopes of the catchment area, which generates sediment of near-zero cosmogenic nuclide concentrations. Farther upstream in the more arid Humahuaca Basin, abandoned fluvial terrace sequences that exceed 100 m in thickness have been linked to wetter episodes during the late Quaternary. Within those fills, preliminary paleo-denudation rates reach values similar to those currently observed in the Del Medio catchment, while modern denudation rates from river sands are similar to the low rates observed from bedrock samples. Taken together, these observations indicate that the Del Medio fan could be a modern analog of those older fill sequences, providing a unique opportunity to link present-day processes in the Del Medio catchment to those that were likely active in the past during wetter climate episodes in the Humahuaca Basin.

  18. A physically-based Distributed Hydrologic Model for Tropical Catchments

    NASA Astrophysics Data System (ADS)

    Abebe, N. A.; Ogden, F. L.

    2010-12-01

    Hydrological models are mathematical formulations intended to represent observed hydrological processes in a watershed. Simulated watersheds in turn vary in their nature based on their geographic location, altitude, climatic variables and geology and soil formation. Due to these variations, available hydrologic models vary in process formulation, spatial and temporal resolution and data demand. Many tropical watersheds are characterized by extensive and persistent biological activity and a large amount of rain. The Agua Salud catchments located within the Panama Canal Watershed, Panama, are such catchments identified by steep rolling topography, deep soils derived from weathered bedrock, and limited exposed bedrock. Tropical soils are highly affected by soil cracks, decayed tree roots and earthworm burrows forming a network of preferential flow paths that drain to a perched water table, which forms at a depth where the vertical hydraulic conductivity is significantly reduced near the bottom of the bioturbation layer. We have developed a physics-based, spatially distributed, multi-layered hydrologic model to simulate the dominant processes in these tropical watersheds. The model incorporates the major flow processes including overland flow, channel flow, matrix and non-Richards film flow infiltration, lateral downslope saturated matrix and non-Darcian pipe flow in the bioturbation layer, and deep saturated groundwater flow. Emphasis is given to the modeling of subsurface unsaturated zone soil moisture dynamics and the saturated preferential lateral flow from the network of macrospores. Preliminary results indicate that the model has the capability to simulate the complex hydrological processes in the catchment and will be a useful tool in the ongoing comprehensive ecohydrological studies in tropical catchments, and help improve our understanding of the hydrological effects of deforestation and aforestation.

  19. Landscape genetic patterns of the rainbow darter Etheostoma caeruleum: a catchment analysis of mitochondrial DNA sequences and nuclear microsatellites.

    PubMed

    Haponski, A E; Bollin, T L; Jedlicka, M A; Stepien, C A

    2009-12-01

    Catchment population structure and divergence patterns of the rainbow darter Etheostoma caeruleum (Percidae: Teleostei), an eastern North American benthic fish, are tested using a landscape genetics approach. Allelic variation at eight nuclear DNA microsatellite loci and two mitochondrial DNA regions [cytochrome (cyt) b gene and control region; 2056 aligned base pairs (bp)] is analysed from 89 individuals and six sites in the Lake Erie catchment (Blanchard, Chagrin, Cuyahoga and Grand Rivers) v. the Ohio River catchment (Big Darby Creek and Little Miami River). Genetic and geographic patterning is assessed using phylogenetic trees, pair-wise F(ST) analogues, AMOVA partitioning, Mantel regression, Bayesian assignment, 3D factorial correspondence and barrier analyses. Results identify 34 cyt b haplotypes, 22 control region haplotypes and 137 microsatellite alleles whose distributions demonstrate marked genetic divergence between populations from the Lake Erie and Ohio River catchments. Etheostoma caeruleum populations in the Lake Erie and Ohio River catchments diverged c. 1.6 mya during the Pleistocene glaciations. Greater genetic separations characterize the Ohio River populations, reflecting their older habitat age and less recent connectivity. Divergence levels within the Lake Erie catchment denote more recent post-glacial origins. Notably, the western Lake Erie Blanchard River population markedly differs from the three central basin tributary samples, which are each genetically distinguishable using microsatellites. Overall relationships among the Lake Erie sites refute a genetic isolation by geographic distance hypothesis. Etheostoma caeruleum populations thus exchange few genes and have low migration among tributaries and catchments. PMID:20738685

  20. Constraining the characteristics of sediment released from tectonically-perturbed catchments

    NASA Astrophysics Data System (ADS)

    Whittaker, A. C.; Attal, M.; Allen, P. A.; Cowie, P. A.

    2009-12-01

    The depositional characteristics of any basin fill are the product of the coupled system of sediment release from hinterland catchments and its evolution during transport downstream. Changes to the tectonic boundary conditions governing the dynamics of erosion in upland catchments will therefore exert a significant effect on the nature and magnitude of sediment supply to channels, and subsequently neighbouring basins. While recent advances in tectonic geomorphology demonstrate the generic coupling between tectonic uplift and landscape denudation, there has been relatively little work to quantify the controls, timing, characteristics and locus of sediment release from tectonically-perturbed upland catchments, and the way in which this signal subsequently evolves downstream within the fluvial system. We address this challenge using (i) field data to evaluate the characteristics and source areas of sediment exported from modern fluvial catchments draining across active normal faults in the Italian Apennines and Greece and (ii) the CHILD landscape evolution model to investigate how the locus and volume of sediment exported from such catchments evolves through time and with the degree of tectonic perturbation. We demonstrate that rivers near the detachment limited end-member undergoing a transient response to an increase in fault uplift rate are associated with significant additional volumetric export of material derived largely from the incised zone upstream of the fault. This response produces bi-modal grain-size distributions with elevated D84 values within the transient reach for catchments eroding hard carbonate bedrock. Our data show the signal is substantially driven by landslide input from coupled hill-slopes, and we demonstrate the amplitude of the landscape response is modulated by the degree of tectonic perturbation. However, for more diffusive catchments, where weaker lithologies are eroded, the coarse fraction grain-size signal is reduced or absent despite a similar degree of tectonic perturbation. These results suggest that transient responses to tectonics control the locus, magnitude and calibre of sediment supply to basins. More widely, this work offers new insights for geomorphologists seeking to decode the interactions between hillslopes, sediment flux and channel incision in perturbed landscapes, and we provide a fresh perspective for sedimentologists trying to predict the characteristics of deposits in hangingwall basins.

  1. Self Organising Maps and Canonical Correlation Analysis: application to catchment classification and PUB

    NASA Astrophysics Data System (ADS)

    di Prinzio, Monica; Castellarin, Attilio; Toth, Elena

    2010-05-01

    The scientific community indicates that the formulation of objective criteria for catchment classification is one of the main objectives for obtaining a better interpretation and representation of the spatiotemporal variability of streamflows. A promising approach to catchment classification, and in general to pattern recognition, makes use of unsupervised neural networks, and in particular Self Organising Maps (SOM), which organise input data through non-linear techniques depending on the intrinsic similarity of the data themselves (see e.g., Toth, HESS, 2009). This study considers a set of some 300 Italian catchments scattered nationwide, for which several descriptors of the streamflow regime and geomorphoclimatic characteristics are available. We qualitatively and quantitatively compared a reference classification, RC, with three alternative classifications, ACs. RC was identified by using indices of the streamflow regime as input to SOM, whereas ACs were identified on the basis of catchment descriptors available for ungauged basins. The first AC adopts the available catchment geomorphoclimatic descriptors as input to SOM. The other ACs were identified by applying SOM to sets of derived variables, which were obtained by applying Principal Component Analysis (PCA, second AC) and Canonical Correlation Analysis (CCA, third AC) to the available indices. First, the similarity between each AC and RC is assessed qualitatively, analysing how the study catchments were grouped together. Second, ACs are compared with RC in terms of accuracy of streamflow prediction. In particular, we performed an extensive cross-validation procedure to quantify nationwide the accuracy of estimates of the mean annual flow, mean annual flood and flood quantiles associated with given exceedance probabilities. Results of the study show that CCA can significantly improve the effectiveness of SOM classifications for the estimation of streamflow regime in ungauged basins.

  2. How tritium illuminates catchment structure

    NASA Astrophysics Data System (ADS)

    Stewart, M.; Morgenstern, U.; McDonnell, J.

    2012-04-01

    Streams contain water which has taken widely-varying times to pass through catchments, and the distribution of ages is likely to change with the flow. Part of the water has 'runoff' straight to the stream with little delay, other parts are more delayed and some has taken years (in some cases decades) to traverse the deeper regolith or bedrock of the catchment. This work aims to establish the significance of the last component, which is important because it can cause catchments to have long memories of contaminant inputs (e.g. nitrate). Results of tritium studies on streams world-wide were accessed from the scientific literature. Most of the studies assumed that there were just two age-components present in the streams (i.e. young and old). The mean ages and proportions of the components were found by fitting simulations to tritium data. It was found that the old component in streams was substantial (average was 50% of the annual runoff) and had considerable age (average mean age was 10 years) (Stewart et al., 2010). Use of oxygen-18 or chloride variations to estimate streamflow mean age usually does not reveal the age or size of this old component, because these methods cannot detect water older than about four years. Consequently, the use of tritium has shown that substantial parts of streamflow in headwater catchments are older than expected, and that deep groundwater plays an active and sometimes even a dominant role in runoff generation. Difficulties with interpretation of tritium in streams in recent years due to interference from tritium due to nuclear weapons testing are becoming less serious, because very accurate tritium measurements can be made and there is now little bomb-tritium remaining in the atmosphere. Mean ages can often be estimated from single tritium measurements in the Southern Hemisphere, because there was much less bomb-tritium in the atmosphere. This may also be possible for some locations in the Northern Hemisphere. Age determination on single samples allows the variation of mean age with streamflow to be investigated, as observed in the Toenepi Catchment in New Zealand where baseflow mean ages varied from 4 to 155 years depending on flow (Morgenstern et al., 2010).

  3. 10Be-derived denudation rates from the Burdekin catchment: The largest contributor of sediment to the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Croke, Jacky; Bartley, Rebecca; Chappell, John; Austin, Jenet M.; Fifield, Keith; Tims, Stephen G.; Thompson, Chris J.; Furuichi, Takahisa

    2015-07-01

    Terrestrial cosmogenic nuclides (TCNs) such as Beryllium-10 (10Be) are now routinely used to reconstruct erosional rates over tens of thousands of years at increasingly large basin scales (> 100,000 km2). In Australia, however, the approach and its assumptions have not been systematically tested within a single, large drainage basin. This study measures 10Be concentrations in river sediments from the Burdekin catchment, one of Australia's largest coastal catchments, to determine long-term (> 10,000 years), time-integrated rates of sediment generation and denudation. A nested-sampling design was used to test for effects of increasing catchment scale on nuclide concentrations with upstream catchment areas ranging from 4 to 130,000 km2. Beryllium-10 concentrations in sediment samples collected from the upstream headwater tributaries and mid-stream locations range from 1.8 to 2.89 × 105 atoms g- 1 and data confirm that nuclide concentrations are well and rapidly mixed downstream. Sediment from the same tributaries consistently yielded 10Be concentrations in the range of their upstream samples. Overall, no decrease in 10Be concentrations can be observed at the range of catchment scales measured here. The mean denudation rate for all river sediment samples throughout the Fanning subcatchment (1100 km2) is 18.47 m Ma- 1, which compares with the estimate at the end of the Burdekin catchment (130,000 km2) of 16.22 m Ma- 1. Nuclide concentrations in the lower gradient western and southern catchments show a higher degree of variability, and several complications emerged as a result of the contrasting geomorphic processes and settings. This study confirms the ability of TCNs to determine long-term denudation rates in Australia and highlights some important considerations in the model assumptions that may affect the accuracy of limited sampling in large, low-gradient catchments with long storage times.

  4. Recasting catchment water balance for water allocation between human and environmental purposes

    NASA Astrophysics Data System (ADS)

    Zhou, S.; Huang, Y.; Wei, Y.; Wang, G.

    2015-01-01

    Rebalancing water allocation between human consumptive uses and the environment in water catchments is a global challenge. The conventional water balance approach which partitions precipitation into evapotranspiration (ET) and surface runoff supports the optimization of water allocations among different human water use sectors under the cap of water supply. However, this approach is unable to support the emerging water management priority issue of allocating water between societal and ecological systems. This paper recast the catchment water balance by partitioning catchment total ET into ET for the society and ET for the natural ecological systems, and estimated the impacts of water allocation on the two systems in terms of gross primary productivity (GPP), in the Murray-Darling Basin (MDB) of Australia over the period 1900-2010. With the recast water balance, the more than 100 year water management in the MDB was divided into four periods corresponding to major changes in basin management: period 1 (1900-1956) expansion of water and land use by the societal system, period 2 (1956-1985) maximization of water and land use by the societal system, period 3 (1985-2002) maximization of water diversion for the societal system, and period 4 (2002-present) rebalancing of water and land use between the societal and ecological systems. The recast water balance provided new understandings of the water and land dynamics between societal and ecological systems in the MDB, and it highlighted the experiences and lessons of catchment water management in the MDB over the last more than 100 years. The recast water balance could serve as the theoretical foundation for water allocation to keep a dynamic balance between the societal and ecological systems within a basin for sustainable catchment development. It provides a new approach to advance the discipline of socio-hydrology.

  5. Nutrient sources in a Mediterranean catchment and their improvement for water quality management

    NASA Astrophysics Data System (ADS)

    Candela, Angela; Viviani, Gaspare

    2010-05-01

    Changes in land-use or management strategies may affect water outflow, sediment and nutrients loads. Thus, there is an increasing demand for quantitative information at the catchment scale that would help decision makers or planners to take appropriate decisions. The characterisation of water status, the description of pollution sources impact, the establishment of monitoring programs and the implementation of river basin management plans require an analysis of the current basin status and estimates of the relative significance of the different sources of pollution. Particularly, in this study the Soil and Water Assessment Tool (SWAT2000) model was considered since it is an integrated hydrological model that simulates both the qualitative as well as quantitative terms of hydrological balances. It is a spatially distributed hydrological model that operates on a daily time step at catchment scale developed by the Agricultural Research Service at the U.S. Department of Agriculture. Its purpose is to simulate water sediment and chemical yields on large river basins and possible impacts of land use, climate changes and watershed management. Integrated hydrological models are, nowadays, needed to support the implementation of integrated water management plans and to comply with the current requirements of the European Water Directive. Actually, they can help in evaluating current water resources, identify pollution sources, evaluate alternative management policies. More specifically, the analysis has been applied to the Oreto catchment (77 Km2), an agricultural and urbanised catchment located in Sicily (Italy). Residential, commercial, farm and industrial settlements cover almost the entire area. The climate is Mediterranean with hot dry summer and rainy winter season. The hydrological response of this basin is dominated by long dry seasons and following wetting-up periods, during which even large inputs of rainfall may produce little or no response at the basin outlet. Regarding the inventory of point and non-point pollutants sources, the river receives a number of point source pollutants from small villages and some outskirts of Palermo, most of them untreated, and non point source pollutants from agricultural cropland and zoo-technical farms. In particular, the Oreto river receives untreated wastewater and stormwater from Altofonte (8200 inhabitants) and Pioppo (2500 inhabitants) . The model was first calibrated using meteorological, flow and water quality data collected at various stations through-out the catchment, in order to predict water and nutrient concentrations at the catchment outlet and then was used to evaluate the potential impact of various management strategies on surface water quality. The results demonstrates that point and non-point polluting sources have to be contiguously analysed because they concur to the definition of river water quality both during wet and dry periods.

  6. Stream Complexity in an Undisturbed Watershed of the Amazon Basin

    NASA Astrophysics Data System (ADS)

    Muttiah, R. S.; Khanal, S.; Janovec, J. P.

    2005-12-01

    The Madre De Dios watershed (drainage area 42,530 km2) which is in the headwater region of the Amazon basin is located in southeastern Peru. The watershed is in nearly pristine conditions with minimal human disturbance. The study area affords a rich research environment in which natural hydrologic processes under heavy rainfall can be studied. The streams in the basin were Strahler ordered, and complexity of catchments (sub-watersheds) were characterized. Implication of catchment complexity on delineating physiographic features will also be presented.

  7. Suspended sediment dynamics of the Biobo River in response to water routing along the catchment

    NASA Astrophysics Data System (ADS)

    Tolorza, V.; Carretier, S.; Andermann, C.; Pinto, L.

    2014-12-01

    Supply-transport feedbacks in catchments involve processes with fundamental consequence for river management, land use and for the prediction of climate-driven sediment fluxes in rivers that are yet little understand. We address the spatial variability in the dynamic of the suspended sediment discharge (Qs, M/T) in a mountain-piedmont system located in the southern-central Andes (Biobo River Basin, 37-39S). In steep catchments, the Q vs. Qs diagrams show a marked seasonal hysteresis curve. In the piedmont, Qs is proportional to Q, without showing hysteresis. The contrast in the hysteresis pattern between catchments with different topographies can be explained by differences in the routing of rainfall-derived water. In the piedmont, most of the rainfall is converted into surface runoff because the water table level is near the surface. In the mountain, groundwater storage imposes large seasonal variations in the fraction of Q that flows at the surface and transports sediment from the hillslopes, which produces hysteresis. By separating the total Q between two frequency components (direct discharge, Qd and base-flow, Qb), we observe the response of Qs to the fraction of water that quickly leaves the catchment after a rainfall event (Qd). Similar results between the mountain and piedmont and the absence of hysteresis simplify the behavior of Qs by a linear relationship with Qd over the entire catchment. Our finding highlight the importance of an adequate hydrological model to understand the erosion and transport processes of a catchment and lead us to propose that the main erosion process along the Biobo catchment is overland flow.

  8. Relict rock glaciers as groundwater storage in alpine catchments - the example of the Seckauer Tauern Range

    NASA Astrophysics Data System (ADS)

    Wagner, Thomas; Pauritsch, Marcus; Winkler, Gerfried

    2015-04-01

    Debris accumulations like relict rock glaciers (RRG) might act as groundwater storages in alpine catchments influencing the discharge dynamics of mountain streams. The degree of influence is related to the hydrometeorological conditions and changes seasonally. Especially during drought and flood events, the storage/buffer abilities of RRGs have an impact on the downstream river network. Stream flow could be assured during low flow periods and peak flows might be dampened during storm events. The assessment of the impact is investigated in the Seckauer Tauern Range, the easternmost subunit of the Niedere Tauern Range. In more detail, the discharge of a spring (Schneben spring) emerging at the front of a RRG draining a catchment of 0.67 km and discharges at gauging stations Finsterliesing and Unterwald further downstream with areal extents of 7.26 and 44.10 km respectively are used as input for a lumped-parameter rainfall-runoff model, a modified version of the GR4J (Perrin et al., 2003). The Schneben spring is 100% influenced by the RRG groundwater storage, as the whole catchment drains through the RRG. The flow dynamics of the other catchments are influenced only partially by RRGs with 15 and 12% as only headwater sections of it are drained by RRGs. The areal extend of the RRG (sub-) catchments, vegetation, debris in general and bare rock are compared to the storage parameters (routing and production store) of the rainfall-runoff model. As such, the influence of RRGs can be identified even in the overall catchment. It can be concluded that RRGs, due to their storage and buffer capabilities and abundance in the Seckauer Tauern Range are important for stream basin management and as a water resource for the sensitive ecosystem in alpine catchments. References: Perrin, C., Michel, C., Andrassian, V. (2003): Improvement of a parsimonious model for streamflow simulation. Journal of Hydrology 279, 275-289.

  9. Seismic controls on contemporary sediment export in the Siret river catchment, Romania

    NASA Astrophysics Data System (ADS)

    Vanmaercke, Matthias; Obreja, Florin; Poesen, Jean

    2014-07-01

    While differences in catchment sediment yield (SY, [t km- 2 y- 1]) are generally attributed to topography, lithology, climate and land use, recent studies have highlighted that also seismic activity may have an important impact on SY. Nonetheless, relatively little is known about the importance of this factor and the processes and mechanisms explaining its influence. Therefore, this study explores the role of seismic activity in explaining spatial and temporal variation in sediment export within the Siret Basin (Romania, 45,000 km2), a catchment with a large variability in seismic activity. Based on previously unpublished long-term (> 30 years) SY measurements for 38 subcatchments of the Siret, we analyze the correlation between average SY, seismic activity and various other catchment characteristics. Our results showed that spatial variation in average SY was indeed strongly correlated with the degree of seismic activity in each catchment (R2 = 0.74). Also catchment lithology explained an important part of the differences in SY (R2 = 0.67). The combination of these two factors accounted for about 80% of the observed variation in SY, while other factors (e.g. topography, land use, climate, and runoff) did not significantly contribute to the explained variance in average SY. To explore the impact of a specific earthquake event on sediment export, we analyzed daily variations in suspended sediment concentrations of 10 subcatchments, five years before and after an earthquake of Mw = 7.4 that affected the Vrancea region in 1977 and triggered a substantial number of landslides. Only one catchment showed a clear (3-fold) increase in sediment concentrations at unit discharge. For the other nine catchments, no consistent increase could be observed. This indicates that the impact of seismic activity on average SY is mainly indirect and not associated with sudden pulses of sediments, caused by earthquake-triggered landslides. Potential mechanisms that could explain such indirect responses are discussed.

  10. IRECCSEM: Evaluating Clare Basin potential for onshore carbon sequestration using magnetotelluric data (Preliminary results). New approaches applied for processing, modeling and interpretation

    NASA Astrophysics Data System (ADS)

    Campanya i Llovet, J.; Ogaya, X.; Jones, A. G.; Rath, V.

    2014-12-01

    The IRECCSEM project (www.ireccsem.ie) is a Science Foundation Ireland Investigator Project that is funded to evaluate Ireland's potential for onshore carbon sequestration in saline aquifers by integrating new electromagnetic data with existing geophysical and geological data. The main goals of the project are to determine porosity-permeability values of the potential reservoir formation as well as to evaluate the integrity of the seal formation. During the Summer of 2014 a magnetotelluric (MT) survey was carried out at the Clare basin (Ireland). A total of 140 sites were acquired including audiomagnetotelluric (AMT), broadband magnetotelluric (BBMT) and long period magnetotelluric (LMT) data. The nominal space between sites is 0.6 km for AMT sites, 1.2 km for BBMT sites and 8 km for LMT sites. To evaluate the potential for carbon sequestration of the Clare basin three advances on geophysical methodology related to electromagnetic techniques were applied. First of all, processing of the MT data was improved following the recently published ELICIT methodology. Secondly, during the inversion process, the electrical resistivity distribution of the subsurface was constrained combining three different tensor relationships: Impedances (Z), induction arrows (TIP) and multi-site horizontal magnetic transfer-functions (HMT). Results from synthetic models were used to evaluate the sensitivity and properties of each tensor relationship. Finally, a computer code was developed, which employs a stabilized least squares approach to estimate the cementation exponent in the generalized Archie law formulated by Glover (2010). This allows relating MT-derived electrical resistivity models to porosity distributions. The final aim of this procedure is to generalize the porosity - permeability values measured in the boreholes to regional scales. This methodology will contribute to the evaluation of possible sequestration targets in the study area.

  11. Sediment yield estimation in mountain catchments of the Camastra reservoir, southern Italy: a comparison among different empirical methods

    NASA Astrophysics Data System (ADS)

    Lazzari, Maurizio; Danese, Maria; Gioia, Dario; Piccarreta, Marco

    2013-04-01

    Sedimentary budget estimation is an important topic for both scientific and social community, because it is crucial to understand both dynamics of orogenic belts and many practical problems, such as soil conservation and sediment accumulation in reservoir. Estimations of sediment yield or denudation rates in southern-central Italy are generally obtained by simple empirical relationships based on statistical regression between geomorphic parameters of the drainage network and the measured suspended sediment yield at the outlet of several drainage basins or through the use of models based on sediment delivery ratio or on soil loss equations. In this work, we perform a study of catchment dynamics and an estimation of sedimentary yield for several mountain catchments of the central-western sector of the Basilicata region, southern Italy. Sediment yield estimation has been obtained through both an indirect estimation of suspended sediment yield based on the Tu index (mean annual suspension sediment yield, Ciccacci et al., 1980) and the application of the Rusle (Renard et al., 1997) and the USPED (Mitasova et al., 1996) empirical methods. The preliminary results indicate a reliable difference between the RUSLE and USPED methods and the estimation based on the Tu index; a critical data analysis of results has been carried out considering also the present-day spatial distribution of erosion, transport and depositional processes in relation to the maps obtained from the application of those different empirical methods. The studied catchments drain an artificial reservoir (i.e. the Camastra dam), where a detailed evaluation of the amount of historical sediment storage has been collected. Sediment yield estimation obtained by means of the empirical methods have been compared and checked with historical data of sediment accumulation measured in the artificial reservoir of the Camastra dam. The validation of such estimations of sediment yield at the scale of large catchments using sediment storage in reservoirs provides a good opportunity: i) to test the reliability of the empirical methods used to estimate the sediment yield; ii) to investigate the catchment dynamics and its spatial and temporal evolution in terms of erosion, transport and deposition. References Ciccacci S., Fredi F., Lupia Palmieri E., Pugliese F., 1980. Contributo dell'analisi geomorfica quantitativa alla valutazione dell'entita dell'erosione nei bacini fluviali. Bollettino della Societ Geologica Italiana 99: 455-516. Mitasova H, Hofierka J, Zlocha M, Iverson LR. 1996. Modeling topographic potential for erosion and deposition using GIS. International Journal of Geographical Information Systems 10: 629-641. Renard K.G., Foster G.R., Weesies G.A., McCool D.K., Yoder D.C., 1997. Predicting soil erosion by water: a guide to conservation planning with the Revised Universal Soil Loss Equation (RUSLE), USDA-ARS, Agricultural Handbook No. 703.

  12. Influence of geology, regolith and soil on fluid flow pathways in an upland catchment in central NSW, Australia

    NASA Astrophysics Data System (ADS)

    Bernardi, Tony

    2014-05-01

    Influence of geology, regolith and soil on fluid flow pathways in an upland catchment in central NSW, Australia. Tony Bernardi and Leah Moore Dryland Salinity Hazard Mitigation Program (DSHMP), University of Canberra, ACT 2601, AUSTRALIA The diversity of salt expression in central NSW has defied classification because salt expression, mobilisation and transport is highly variable and is typically site specific. Hydrological models are extensively used to simulate possible outcomes for a range of land use changes to mitigate the mobilisation and transport of salt into the streams or across the land surface. The ability of these models to mimic reality can be variable thereby reducing the confidence in the models outputs and uptake of strategic management changes by the community. This study focuses on a 250 ha semi-arid sub-catchment of Little River catchment in central west NSW in the Murray-Darling Basin, Australia. We propose that an understanding the structure of the landforms and configuration of rock, regolith and soil materials at the study site influences fluid flow pathways in the landscape and can be related to observed variations in the chemical composition and salinity of surface and aquifer water. Preliminary geological mapping of the site identified the dominant rock type as a pink and grey dacite and in localised mid-slope areas, a coarsely crystalline biotite-phyric granodiorite. Samples were taken at regular intervals from natural exposures in eroded stream banks and in excavations made during the installation of neutron moisture meter tubes. In order to establish mineral weathering pathways, samples were taken from the relatively unweathered core to the outer weathered 'onion skins' of corestones on both substrates, and then up through the regolith profile, including the soil zone, to the land surface. X-ray diffraction (XRD) analysis and X-ray fluorescence (XRF) was conducted on the rock and soil/saprock samples. Electromagnetic induction (EMI) profile data were compiled from previous work with colleagues in this area. Preliminary interpretation of the mapping and the geophysics is that there is a three-layer framework for groundwater modelling: fractured granitic rock with an irregular upper surface, finer-grained (volcanic) rock that has either mantled the older granite or has been intruded into, and a weathering profile developed in relation to the land surface. More careful interpretation of the intervals that shallow and deep piezometers and shallow and deep bores are sampling indicates that variability in water chemistry between holes can, in part, be explained because they are sampling different materials in the sub-surface geology/regolith geology. Quartz is a relatively resistant phase throughout the profiles. For both substrates there is a decrease in the feldspar in increasingly weathered regolith materials, with a corresponding increase in kaolinite clay. There is increased homogenisation of the profile, and some horizonation due to pedogenic processes (e.g. bioturbation, illuviation of fines down profile) nearer the land surface. This results in a concentration of more resistant phases (quartz and remnant primary feldspar as sands) at the land surface over the granitic substrate, however kaolinite persists in the profile over the finer substrate. The presence of measurable ferruginous oxides and sesquioxides relates to localised percolation of oxidising fluids through the profiles. Understanding the configuration and composition of rocks and regolith materials in the Baldry catchment facilitates interpretation of observed patterns in hydrological analyses.

  13. Quantifying the controls on grain size export from tectonically perturbed catchments: Case studies from Sicily, Calabria and Abruzzo, Italy

    NASA Astrophysics Data System (ADS)

    Whittaker, A.; Erhardt, S.; Norori-McCormac, A.; Knight, F.

    2012-04-01

    The magnitude, locus and characteristics of sediment export from catchments to neighbouring basins plays a significant role in controlling depositional stratigraphy. Fundamentally, the boundary conditions for sediment release from catchments are set by tectonics and climate, modulated by lithologic, hydrologic and geomorphic controls operating over the relevant time or length scale. A predictive understanding of sediment export to basins therefore requires (i) the integration of data illustrating the characteristics of sediment delivery within catchments and (ii) detailed constraints on how this supply signal evolves down-system, for a wide range of controlling variables. Here we address this challenge. Firstly, we present a detailed data study linking hillslope sediment supply to trunk stream grain size evolution for three catchments with drainage areas > 30 km2 in northern Sicily where tectonic uplift rates are > 1 mm/yr and where lithologies are well-mapped, using both sieved weight fraction and Wolman point count methodologies. We find that sediment input from coarse debris flows, rather than landslides, plays a dominant role in setting channel grain size and that coarse-fraction sediment export from catchments is intimately linked to channel-hillslope geomorphic coupling. Secondly, we present detailed data on grain size export from the outlets of more than 40 tectonically perturbed catchments across Sicily, Calabria and Abruzzo, where we have excellent constraints on tectonic uplift rates, lithology and catchment hydraulic geometry. We demonstrate that for catchments in topographic steady-state, grain size release is strongly controlled by rock type, but is insensitive to drainage area and local uplift rates that are < 1 mm/yr. In contrast, for catchments responding transiently to tectonics, the calibre of sediment release is strongly controlled by the degree of tectonic perturbation. The southern Italian data-sets allow us to provide first order estimates of the volume and grain size distribution of sediment exported to the straits of Messina as a whole, and we use terrace data to show there has been little change to this sediment release signal in the last 200 kyr. Together, these results allow us to evaluate the relative importance of upstream source controls in setting the characteristics of sediment release from tectonically perturbed catchments to basins and provide new data to test the outputs of sediment routing system models.

  14. The impact of land management in agricultural catchments on groundwater pollution levels

    NASA Astrophysics Data System (ADS)

    Matysik, Magdalena

    2014-10-01

    Agricultural activity results in water pollution from nitrogen and phosphorus compounds. Increased concentrations of nitrogen compounds pose a threat to animal and human health. The purpose of this study was to determine the impact of agriculture in a catchment basin on the level of groundwater pollution from biogenic compounds. Spatial analysis of the land cover was conducted using a GIS and was based on data from the Corine Land Cover databases.

  15. Geomorphological characterization of endorheic basins in northern Chile

    NASA Astrophysics Data System (ADS)

    Dorsaz, J.; Gironas, J. A.; Escauriaza, C. R.; Rinaldo, A.

    2011-12-01

    Quantitative geomorphology regroups a large number of interesting tools to characterize natural basins across scales. The application of these tools to several river basins allows the description and comparison of geomorphological properties at different spatial scales as oppose to more traditional descriptors that are typically applied at a single scale, meaning the catchment scale. Most of the recent research using these quantitative geomorphological tools has focused on open catchments and no specific attention has been given to endorheic basins, and the possibility of having particular features that distinguish them from exorheic catchments. The main objective of our study is to characterize endorheic basins and investigate whether these special geomorphological features can be identified. Because scaling invariance is a widely observed and relatively well quantified property of open basins, it provides a suitable tool to characterize differences between the geomorphology of closed and open basins. Our investigation focuses on three closed basins located in northern Chile which describe well the diversity in the geomorphology and geology of this arid region. Results show that endhoreic basins exhibit different slope-area and flow paths sinuosity regimes compared to those observed in open basins. These differences are in agreement with the particular self-similar behavior across spatial scales of the Euclidean length of subcatchments, as well as the Hack's law and Horton's ratios. These regimes imply different physical processes inside the channel network regardless of the basin area, and they seem to be related to the endorheic character of these basins. The analysis of the probability density functions of contributing areas and lengths to the lower region shows that the hypothesis of self-similarity can also be applied to closed basins. Theoretical expressions for these distributions were derived and validated by the data. Future research will focus on (1) applying similar analyses in other locations and comparing the results, and (2) understanding and modeling the effects of groundwater in forming the landscape of these arid regions.

  16. The hydrological regime of a forested tropical Andean catchment

    NASA Astrophysics Data System (ADS)

    Clark, K. E.; Torres, M. A.; West, A. J.; Hilton, R. G.; New, M.; Horwath, A. B.; Fisher, J. B.; Rapp, J. M.; Robles Caceres, A.; Malhi, Y.

    2014-12-01

    The hydrology of tropical mountain catchments plays a central role in ecological function, geochemical and biogeochemical cycles, erosion and sediment production, and water supply in globally important environments. There have been few studies quantifying the seasonal and annual water budgets in the montane tropics, particularly in cloud forests. We investigated the water balance and hydrologic regime of the Kosipata catchment (basin area: 164.4 km2) over the period 2010-2011. The catchment spans over 2500 m in elevation in the eastern Peruvian Andes and is dominated by tropical montane cloud forest with some high-elevation puna grasslands. Catchment-wide rainfall was 3112 414 mm yr-1, calculated by calibrating Tropical Rainfall Measuring Mission (TRMM) 3B43 rainfall with rainfall data from nine meteorological stations in the catchment. Cloud water input to streamflow was 316 116 mm yr-1 (9.2% of total inputs), calculated from an isotopic mixing model using deuterium excess (Dxs) and ?D of waters. Field streamflow was measured in 2010 by recording height and calibrating to discharge. River run-off was estimated to be 2796 126 mm yr-1. Actual evapotranspiration (AET) was 688 138 mm yr-1, determined using the Priestley and Taylor-Jet Propulsion Laboratory (PT-JPL) model. The overall water budget was balanced within 1.6 13.7%. Relationships between monthly rainfall and river run-off follow an anticlockwise hysteresis through the year, with a persistence of high run-off after the end of the wet season. The size of the soil and shallow groundwater reservoir is most likely insufficient to explain sustained dry-season flow. Thus, the observed hysteresis in rainfall-run-off relationships is best explained by sustained groundwater flow in the dry season, which is consistent with the water isotope results that suggest persistent wet-season sources to streamflow throughout the year. These results demonstrate the importance of transient groundwater storage in stabilising the annual hydrograph in this region of the Andes.

  17. A preliminary assessment of streamflow gains and losses for selected stream reaches in the lower Guadalupe River Basin, Texas, 2010-12

    USGS Publications Warehouse

    Wehmeyer, Loren L.; Winters, Karl E.; Ockerman, Darwin J.

    2013-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers–Fort Worth District, the Texas Water Development Board, the Guadalupe-Blanco River Authority, and the Edwards Aquifer Authority, investigated streamflow gains and losses in the lower Guadalupe River Basin during four selected base-flow periods in March 2010, April 2011, August 2011, and, for a stream reach between Seguin, Tex., and Gonzales, Tex., in September 2012. Major sources of streamflow in this basin include releases from Canyon Lake, inflow from major springs (Comal Springs, San Marcos Springs, and Hueco Springs), and base flow (groundwater seeping to streams). Streamflow and spring-flow data were collected at 35 streamflow-gaging stations (including 6 deployed for this study) during the base-flow periods. This report describes streamflow in the lower Guadalupe River Basin, which consists of the Guadalupe River drainage basin downstream from Canyon Lake to the Guadalupe River near Tivoli, Tex. Streamflow conditions in the lower Guadalupe River Basin were analyzed by computing surface-water budgets for reaches of the lower Guadalupe River and tributary streams. Streamflow gains and losses were mapped for reaches where the computed gain or loss was greater than the uncertainty in the computed streamflow at the upstream and downstream ends of the reach. During the March 15–21, 2010, base-flow period, five reaches had gains greater than the uncertainty in the computed streamflow, including reach 1 on the Guadalupe River, which gained 130 cubic feet per second (ft3/s), and reach 3 on the Comal River, which gained 359 ft3/s. Streamflow gains during March 2010 primarily were derived from (1) inflow from the Edwards aquifer outcrop, including Hueco Springs and Comal Springs; (2) flow conveyed through the alluvium of the streambed; (3) inflows from the Carrizo-Wilcox aquifer and the Yegua Jackson aquifer; and (4) groundwater inflows from the Gulf Coast aquifer, which are enhanced by seepage losses from Coleto Creek Reservoir. During this base-flow period, none of the reaches had a loss greater in magnitude than the uncertainty in the computed streamflow. During the April 10–16, 2011, base-flow period, three reaches had gains greater than the uncertainty in the computed streamflow. Among these three reaches were reach 1 on the Guadalupe River, which gained 40.7 ft3/s, and reach 3 on the Comal River, which gained 271 ft3/s—reaches where streamflow gains were also measured in March 2010. Streamflow gains during April 2011 primarily were derived from (1) inflow from the Edwards aquifer outcrop, including Hueco Springs and Comal Springs; and (2) inflows from the Carrizo-Wilcox aquifer. During this base-flow period, three reaches had losses greater in magnitude than the uncertainty in the computed streamflow. A reach of the Blanco River near Kyle, Tex. (reach 10), lost 18.7 cubic feet per second (ft3/s). Much of this loss likely entered the groundwater system through the numerous faults that intersect the stream channel northwest of Kyle. The reach that included the confluence of the Guadalupe and San Marcos Rivers (reach 17) lost 155 ft3/s, likely as recharge to the Sparta and Queen City aquifers. During the August 19–25, 2011, base-flow period, three reaches had gains greater than the uncertainty in the computed streamflow, including reach 3 on the Comal River (168 ft3/s gain), which was one of the reaches where gains in streamflow also were measured in March 2010 and April 2011. Streamflow gains in August 2011 were primarily from (1) inflows from Comal Springs, (2) inflows from the Yegua Jackson aquifer, and (3) groundwater inflows from the Gulf Coast aquifer, which are enhanced by seepage losses from Coleto Creek Reservoir. During this base-flow period, five reaches had losses greater in magnitude than the uncertainty in the computed streamflow. The reach including the confluence of the Guadalupe and Comal Rivers lost 82.8 ft3/s. Much of that loss likely seeped into the local groundwater system. The reach of the Guadalupe River south of New Braunfels, Tex., to Seguin, Tex., lost 53.5 ft3/s. Part of that loss may have been from seepage through streambed alluvium. Reaches 9 and 10 of the Blanco River near Kyle lost 2.20 and 6.60 ft3/s, respectively, likely as infiltration through numerous faults intersecting the stream channel northwest of Kyle. Plum Creek between Lockhart, Tex., and Luling, Tex., lost 2.11 ft3/s, likely as recharge to the Carrizo-Wilcox aquifer. A base-flow period during September 22–28, 2012, was studied for the reach of the Guadalupe River between Seguin and Gonzalez, including flows from San Marcos River and Plum Creek. During this period, for the Guadalupe River reach between Seguin and Oak Forest, no computed gains or losses were greater in magnitude than the uncertainty in the computed streamflow.

  18. Monitoring the runoff response of an ephemeral rocky basin: a case study in the Dolomites (North-Eastern Italy)

    NASA Astrophysics Data System (ADS)

    Cavalli, M.; Trevisani, S.; Marchi, L.; Penna, D.; Borga, M.; Dalla Fontana, G.

    2012-04-01

    In high elevation alpine catchments, first-order streams are often constituted by steep and narrow channels bound by cliffs. These channels frequently have a structural control imposed by fractures and faults in bedrock and typically constitute temporary streams where snowmelt processes strongly influence runoff. Rocky headwater basins show a different hydrological response with respect to soil-mantled basins and their hydrology is poorly known due to the lack of widespread monitoring sites. Herein we present the preliminary results achieved through an experimental hydro-meteorological monitoring network setup in a 0.1 km2 rocky headwater basin located on the southern flank of the Sella Group in the Dolomites (North-Eastern Italy). Elevation ranges between 2700 m, at the outlet, and 3174 m, with an average value of 2950 m. Geology is constituted mainly by the Norian "Dolomia Principale" (Dolomite) featuring a complex structural setting. The monitoring network, active since 2009, is designed with three rain gauges with a time rate of 5 minutes. Two are located at 2609 and 2597 m (close to the outlet), and the third is located on the divide in the central part of the basin (2911 m). Runoff at the outlet is monitored by a pressure transducer. The time interval was set at 5 minutes in the summer months in order to capture the stream response due to intense and spatially-concentrated rainfall events. In winter the pressure transducer is maintained active with a time rate of 30 minutes so as to be ready to register in spring the stream response due to snowmelt. In the summer 2011, some precipitation, runoff, snow and spring water samples for isotopic analysis (?18O and ?2H) were collected aiming to better characterize the origin of subsurface water and the main sources to runoff. Preliminary results show ephemeral presence of runoff, mostly occurring during snowmelt (from May to early July) and after intense summer rainstorms. The lag-time from precipitation centroid to runoff peak (on the order of about 1 hour) is rather long for a very small and steep basin. This is likely due to the presence of fractured bedrock that creates a shallow, subsurface reservoir and increases the catchment response time. Isotopic data of water samples well reflect the precipitation signal indicating reduced evaporation processes during the transfer of the water input to the outlet. Moreover, the isotopic composition of streamflow is close to that of the sampled springs but less depleted than snowmelt samples, revealing a possible contribution to runoff of snowmelt water mixed with subsurface water previously stored in the system.

  19. Storage as a Metric of Catchment Comparison

    USGS Publications Warehouse

    McNamara, J.P.; Tetzlaff, D.; Bishop, K.; Soulsby, C.; Seyfried, M.; Peters, N.E.; Aulenbach, Brent T.; Hooper, R.

    2011-01-01

    The volume of water stored within a catchment, and its partitioning among groundwater, soil moisture, snowpack, vegetation, and surface water are the variables that ultimately characterize the state of the hydrologic system. Accordingly, storage may provide useful metrics for catchment comparison. Unfortunately, measuring and predicting the amount of water present in a catchment is seldom done; tracking the dynamics of these stores is even rarer. Storage moderates fluxes and exerts critical controls on a wide range of hydrologic and biologic functions of a catchment. While understanding runoff generation and other processes by which catchments release water will always be central to hydrologic science, it is equally essential to understand how catchments retain water. We have initiated a catchment comparison exercise to begin assessing the value of viewing catchments from the storage perspective. The exercise is based on existing data from five watersheds, no common experimental design, and no integrated modelling efforts. Rather, storage was estimated independently for each site. This briefing presents some initial results of the exercise, poses questions about the definitions and importance of storage and the storage perspective, and suggests future directions for ongoing activities. ?? 2011 John Wiley & Sons, Ltd.

  20. Constraining sediment fluxes and grain-size characteristics in tectonically-perturbed catchments.

    NASA Astrophysics Data System (ADS)

    Whittaker, A. C.; Attal, M.; Allen, P. A.

    2009-04-01

    The depositional characteristics of any basin fill (the sink) are fundamentally a product of the coupled system of sediment release from hinterland catchments (the source) and its evolution during transport downstream. Changes to the tectonic boundary conditions governing the dynamics of erosion in upland catchments will therefore exert a significant effect on the nature and magnitude of sediment supply to neighbouring basins. While recent advances in tectonic geomorphology demonstrate the generic coupling between tectonic uplift and landscape denudation, there has been relatively little work to quantify the timing, characteristics and locus of sediment release from tectonically-perturbed upland catchments, and the way in which this signal subsequently evolves downstream within the fluvial system. We address this challenge using (i) field data to evaluate the characteristics and source areas of sediment exported from modern fluvial catchments draining across active normal faults in the Central Apennines in Italy and (ii) the CHILD landscape evolution model to investigate how the locus and volume of sediment exported from such catchments evolves through time and with the degree of tectonic perturbation. We demonstrate that catchments undergoing a transient response to an increase in fault uplift rate at 0.8 Ma are associated with significant volumetric export of material derived largely from an incised zone upstream of the fault, producing bi-modal grain-size distributions with elevated D84values within the transient reach. This response is substantially driven by input from coupled hill-slopes, and we show the amplitude and timescale of the landscape response is modulated by the degree of tectonic perturbation. Our results challenge the view the sediment is sourced uniformly from tectonically active catchments, and demonstrate that transient responses to tectonics control the locus, magnitude and calibre of sediment supply to basins. More widely, this work offers new insights for geomorphologists seeking to decode the interactions between hill-slopes, sediment flux and channel incision in transient landscapes, and we provide a fresh perspective for sedimentologists trying to predict proximal hanging-wall stratigraphy in normal fault bounded terrains.

  1. Anadarko Basin conodont studies

    USGS Publications Warehouse

    Repetski, John E.

    1989-01-01

    Preliminary analysis of early Paleozoic conodonts from the subsurface within and adjacent to the Anadarko basin demonstrates their utility in stratigraphic and thermal evolution studies in the basin. More than 100 samples from 30 drill holes produced conodonts that can be correlated with faunas known from rock sequences exposed along the southern flanks of the basin. For the Middle Ordovician to Devonian, extant biozonations and/or recent published literature based on Oklahoma surface sections allow good biostratigraphic correlation into the subsurface and often allow testing of physical correlations. In contrast, conodonts from the Arbuckle Group (Lower to Middle Ordovician) are less well known. Faunas from the upper half of the group are documented only in unpublished theses, and published faunas are in need of restudy and revision. However, this limited information, along with work in progress in Oklahoma and data from carbonate platform facies elsewhere in North America, still permit correlations into the subsurface with the promise of increasingly improved resolution.

  2. An uncertainty assessment of discharge projections for eight Swiss catchments

    NASA Astrophysics Data System (ADS)

    Addor, Nans; Rössler, Ole; Köplin, Nina; Bernhard, Luzi; Bosshard, Thomas; Weingartner, Rolf; Seibert, Jan

    2013-04-01

    Projections of discharge under future climate are impaired by uncertainties arising from different sources: the emission scenarios, the climate models, the post-processing of the climate projections, the hydrological models structure and parameterisation. In this project we investigated the contribution of each of these sources to the final simulation uncertainty for discharge using analyses of variance (ANOVA) in eight catchments representative of the typical Swiss discharge regimes. The catchments are distributed among the Jura, the Swiss Plateau and the Alps, and are known to react differently to climate change. We used climate projections of the CH2011 dataset obtained from the Center for Climate Systems Modeling (C2SM). This dataset consists of two types of projections, both based on the climate model runs of the ENSEMBLES project: one relies on the delta change technique applied to 10 runs and the other is based on a Bayesian multi-model approach combining 20 runs until 2050, and then 14 runs until 2099. In addition to the climate projections for emission scenario A1B chosen for the ENSEMBLES project, the CH2011 team generated simulations for the scenarios A2 and RCP3PD using pattern scaling. This enabled us to address the influence of the uncertainty in green house gases emissions on discharge projections. We ran hydrological simulations using three conceptual models: HBV, PREVAH and WaSiM. HBV and PREVAH rely on a similar reservoir structure, while WaSiM uses the process-oriented Richards-equation approach. PREVAH and WaSiM use a higher level of spatial discretization than the lumped HBV model. The use of the three different models allowed evaluation of the sensitivity of discharge projections to the hydrological model complexity and structure. Simulations were run for the periods 2020-2049, 2045-2074 and 2070-2099 to assess the variation of the different sources of uncertainty over time. The pattern scaling enabled the assessment of uncertainty arising from the emission scenarios in ENSEMBLES simulations and preliminary results suggest that this uncertainty is dominant by the end of the century for the majority of the catchments. Furthermore, in contrast to similar studies on uncertainty quantification that focus on a single catchment or geographic region, our setting demonstrates that the respective contribution of the different sources of uncertainty varies with catchment properties.

  3. Preliminary report on fluid inclusions from halites in the Castile and lower Salado formations of the Delaware Basin, southeastern New Mexico. [Freezing-point depression

    SciTech Connect

    Stein, C.L.

    1985-09-01

    A suite of samples composed primarily of halite from the upper Castile and lower Salado Formations of the Permian Basin was selected from Waste Isolation Pilot Plant (WIPP) core for a reconnaissance study of fluid inclusions. Volume percent of these trapped fluids averaged 0.7% to 1%. Freezing-point depressions varied widely and appeared to be unrelated to fluid-inclusion type, to sedimentary facies, or to stratigraphic depth. However, because very low freezing points were usually associated with anhydrite, a relation may exist between freezing-point data and lithology. Dissolved sulfate values were constant through the Castile, then decreased markedly with lesser depth in the lower Salado. This trend correlates very well with observed mineralogy and is consistent with an interpretation of the occurrence of secondary polyhalite as a result of gypsum or anhydrite alteration with simultaneous consumption of dissolved sulfate from the coexisting fluids. Together with the abundance and distribution of fluid inclusions in primary or ''hopper'' crystal structures, this evidence suggests that inclusions seen in these halites did not migrate any significant geographical distance since their formation. 28 refs., 17 figs., 2 tabs.

  4. Influence of basin connectivity on sediment source, transport, and storage within the Mkabela Basin, South Africa

    NASA Astrophysics Data System (ADS)

    Miller, J. R.; Mackin, G.; Lechler, P.; Lord, M.; Lorentz, S.

    2013-02-01

    The management of sediment and other non-point source (NPS) pollution has proven difficult, and requires a sound understanding of particle movement through the drainage system. The primary objective of this investigation was to obtain an understanding of NPS sediment source(s), transport, and storage within the Mkabela Basin, a representative agricultural catchment within the KwaZulu-Natal Midlands of eastern South Africa, by combining geomorphic, hydrologic and geochemical fingerprinting analyses. The Mkabela Basin can be subdivided into three distinct subcatchments that differ in their ability to transport and store sediment along the axial valley. Headwater (upper catchment) areas are characterized by extensive wetlands that act as significant sediment sinks. Mid-catchment areas, characterized by higher relief and valley gradients, exhibit few wetlands, but rather are dominated by a combination of alluvial and bedrock channels that are conducive to sediment transport. The lower catchment exhibits a low-gradient alluvial channel that is boarded by extensive riparian wetlands that accumulate large quantities of sediment (and NPS pollutants). Fingerprinting studies suggest that silt- and clay-rich layers found within wetland and reservoir deposits of the upper and upper-mid subcatchments are derived from the erosion of fine-grained, valley bottom soils frequently utilized as vegetable fields. Coarser-grained deposits within these wetlands and reservoirs result from the erosion of sandier hillslope soils extensively utilized for sugar cane, during relatively high magnitude runoff events that are capable of transporting sand-sized sediment off the slopes. Thus, the source of sediment to the axial valley varies as a function of sediment size and runoff magnitude. Sediment export from upper to lower catchment areas was limited until the early 1990s, in part because the upper catchment wetlands were hydrologically disconnected from lower parts of the watershed during low to moderate flood events. The construction of a drainage ditch through a previously unchanneled wetland altered the hydrologic connectivity of the catchment, allowing sediment to be transported from the headwaters to the lower basin where much of it was deposited within riparian wetlands. The axial drainage system is now geomorphically and hydrologically connected during events capable of overflowing dams located throughout the study basin. The study indicates that increased valley connectivity partly negated the positive benefits of controlling sediment/nutrient exports from the catchment by means of upland based, best management practices.

  5. Process type identification in torrential catchments

    NASA Astrophysics Data System (ADS)

    Heiser, Micha; Scheidl, Christian; Eisl, Julia; Spangl, Bernhard; Hbl, Johannes

    2015-04-01

    The classification of torrential processes takes place according to factors like sediment concentration and flow behavior and ranges from fluvial process types, including water floods and fluvial sediment transport processes, to fluvial mass movements such as debris flows. This study hypothises a context between basic geomorphological disposition parameters and potential dominant flow process types in steep headwater catchments. Thus, examined catchments were selected based on a historical event documentation of torrential events in the Austrian Alps. In total, 84 catchments could be analysed, and 11 different morphometric parameters were considered. To predict the dominant torrential process type within a catchment, a naive Bayes classifier, a decision tree model, and a multinomial regression model was trained against the compiled geomorphological disposition parameters. All models as well as their combination were compared, based on bootstrapping and complexity. The presented classification model with the lowest prediction error for our data might help to identify the most likely torrential process within a considered catchment.

  6. Potential of using WATCH forcing data to model a low land river basin of the upper Murray-Darling basin in Australia

    NASA Astrophysics Data System (ADS)

    Kundu, D.; Van Ogtrop, F. F.; Vervoort, R. W.

    2014-12-01

    Scattered station based climate data is often not sufficient to describe the dynamics of the catchment processes and efficiently manage the water resources. Therefore, a lot of focus has been to identify alternative distributed data sources, such as; remotely sensed data or global re-analysis data. Hence, this study uses the Water and Global Change (WATCH) forcing data, based on 40 years ECMWF Re-Analysis (ERA-40), to model a semi-arid low land flood plain river basin in a data sparse region. The semi-distributed Soil Water Assessment Tool (SWAT) was used to model the river basin (Warrego, 52140.6 square km) located in the upper Murray-Darling basin in Eastern Australia. Multi station model calibration was achieved using the Sequential Uncertainty Fitting -2 (SUFI-2) algorithm with the Nash Sutcliffe Efficiency (NSE) as the goal function against monthly observed flow data. Modelling of a low land river system is highly challenging, due to topographic heterogeneity, nonlinear climatic behavior and sparse observed flow data with extended periods of zero flows. Preliminary simulation results indicate a NSE of 0.26 to 0.86 for the calibration period and 0.04 to 0.47 for the validation period. Furthermore, the volume fraction explained by the model ranged from 0.69 to 2.71 in the validation period. While the unsatisfactory results may be attributed to the SWAT modelling framework, which struggles with modelling flow in flat flood plains, the study does reveal the potential to use remotely sensed data in low land river basins with little or no climate data.

  7. Attributes for NHDPlus catchments (Version 1.1) for the conterminous United States: STATSGO soil characteristics

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This data set represents estimated soil variables compiled for every catchment of NHDPlus for the conterminous United States. The variables included are cation exchange capacity, percent calcium carbonate, slope, water-table depth, soil thickness, hydrologic soil group, soil erodibility (k-factor), permeability, average water capacity, bulk density, percent organic material, percent clay, percent sand, and percent silt. The source data set is the State Soil ( STATSGO ) Geographic Database (Wolock, 1997). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

  8. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Level 3 Ecoregions

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This data set represents the estimated area of level 3 ecological landscape regions (ecoregions), as defined by Omernik (1987), compiled for every catchment of NHDPlus for the conterminous United States. The source data set is Level III Ecoregions of the Continental United States (U.S. Environmental Protection Agency, 2003). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

  9. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Physiographic Provinces

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This dataset represents the area of each physiographic province (Fenneman and Johnson, 1946) in square meters, compiled for every catchment of NHDPlus for the conterminous United States. The source data are from Fenneman and Johnson's Physiographic Provinces of the United States, which is based on 8 major divisions, 25 provinces, and 86 sections representing distinctive areas having common topography, rock type and structure, and geologic and geomorphic history (Fenneman and Johnson, 1946). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

  10. Attributes for NHDPlus catchments (version 1.1) for the conterminous United States: surficial geology

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This data set represents the area of surficial geology types in square meters compiled for every catchment of NHDPlus for the conterminous United States. The source data set is the "Digital data set describing surficial geology in the conterminous US" (Clawges and Price, 1999). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

  11. Attributes for NHDPlus Catchments (Version 1.1) in the Conterminous United States: Bedrock Geology

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This data set represents the area of bedrock geology types in square meters compiled for every catchment of NHDPlus for the conterminous United States. The source data set is the "Geology of the Conterminous United States at 1:2,500,000 Scale--A Digital Representation of the 1974 P.B. King and H.M. Beikman Map" (Schuben and others, 1994). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18

  12. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Hydrologic Landscape Regions

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This data set represents the area of Hydrologic Landscape Regions (HLR) compiled for every catchment of NHDPlus for the conterminous United States. The source data set is a 100-meter version of Hydrologic Landscape Regions of the United States (Wolock, 2003). HLR groups watersheds on the basis of similarities in land-surface form, geologic texture, and climate characteristics. The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

  13. Attributes for NHDPlus Catchments (Version 1.1): Level 3 Nutrient Ecoregions, 2002

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMotte, Andrew E.

    2010-01-01

    This data set represents the area of each level 3 nutrient ecoregion in square meters, compiled for every catchment of NHDPlus for the conterminous United States. The source data are from the 2002 version of the U.S. Environmental Protection Agency's (USEPA) Aggregations of Level III Ecoregions for National Nutrient Assessment & Management Strategy (USEPA, 2002). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

  14. Attributes for NHDplus Catchments (Version 1.1) for the Conterminous United States: Population Density, 2000

    USGS Publications Warehouse

    Wieczorek, Michael E.; LaMottem, Andrew E.

    2010-01-01

    This data set represents the average population density, in number of people per square kilometer multiplied by 10 for the year 2000, compiled for every catchment of NHDPlus for the conterminous United States. The source data set is the 2000 Population Density by Block Group for the Conterminous United States (Hitt, 2003). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

  15. The Saale-Project -A multidisciplinary approach towards sustainable integrative catchment management -

    NASA Astrophysics Data System (ADS)

    Bongartz, K.; Flgel, W. A.

    2003-04-01

    In the joint research project Development of an integrated methodology for the sustainable management of river basins The Saale River Basin example, coordinated by the Centre of Environmental Research (UFZ), concepts and tools for an integrated management of large river basins are developed and applied for the Saale river basin. The ultimate objective of the project is to contribute to the holistic assessment and benchmarking approaches in water resource planning, as required by the European Water Framework Directive. The study presented here deals (1) with the development of a river basin information and modelling system, (2) with the refinement of a regionalisation approach adapted for integrated basin modelling. The approach combines a user friendly basin disaggregation method preserving the catchments physiographic heterogeneity with a process oriented hydrological basin assessment for scale bridging integrated modelling. The well tested regional distribution concept of Response Units (RUs) will be enhanced by landscape metrics and decision support tools for objective, scale independent and problem oriented RU delineation to provide the spatial modelling entities for process oriented and distributed simulation of vertical and lateral hydrological transport processes. On basis of this RUs suitable hydrological modelling approaches will be further developed with strong respect to a more detailed simulation of the lateral surface and subsurface flows as well as the channel flow. This methodical enhancement of the well recognised RU-concept will be applied to the river basin of the Saale (Ac: 23 179 km2) and validated by a nested catchment approach, which allows multi-response-validation and estimation of uncertainties of the modelling results. Integrated modelling of such a complex basin strongly influenced by manifold human activities (reservoirs, agriculture, urban areas and industry) can only be achieved by coupling the various modelling approaches within a well defined model framework system. The latter is interactively linked with a sophisticated geo-relational database (DB) serving all research teams involved in the project. This interactive linkage is a core element comprising an object-oriented, internet-based modelling framework system (MFS) for building interdisciplinary modelling applications and offering different analysis and visualisation tools.

  16. Collaborative knowledge in catchment research networks

    NASA Astrophysics Data System (ADS)

    Macleod, Christopher Kit

    2015-04-01

    There is a need to improve the production, sharing and use of collaborative knowledge of catchment systems through networks of researchers, policy makers and practitioners. This requires greater levels of systems based integrative research. In parallel to the growing realization that greater levels of collaborative knowledge in scientific research networks are required, a digital revolution has been taking place. This has been driven primarily by the emergence of distributed networks of computers and standards-based interoperability. The objective of this paper is to present the status and research needs for greater levels of systems based integrative research for the production, sharing and use of collaborative knowledge in catchment research networks. To enable increased levels of integrative research depends on development and application of digital technologies to improve collection, use and sharing of data and devise new knowledge infrastructures. This paper focuses on the requirements for catchment observatories that integrate existing and novel physical, social and digital networks of knowledge infrastructures. To support this focus, I present three leading international examples of collaborative networks of catchment researchers and their development of catchment observatories. In particular, the digital infrastructures they have developed to support collaborative knowledge in catchment research networks. These examples are from North America (NSF funded CUAHSI HIS) and from Europe (UK NERC funded EVOp and the German Helmholtz Association Centers funded TERENO/TEODOOR). These exemplars all supported advancing collaborative knowledge in catchment research networks through the development of catchment observatories. I will conclude by discussing the future research directions required for greater levels of production, sharing and use of collaborative knowledge in catchment research networks based on catchment systems science.

  17. Influence of basin connectivity on sediment source, transport, and storage within the Mkabela Basin, South Africa

    NASA Astrophysics Data System (ADS)

    Miller, J. R.; Mackin, G.; Lechler, P.; Lord, M.; Lorentz, S.

    2012-09-01

    The management of sediment and other non-point source (NPS) pollution has proven difficult, and requires a sound understanding of particle movement through the drainage system. The primary objective of this investigation was to obtain an understanding of NPS sediment source(s), transport, and storage within the Mkabela basin, a representative agricultural catchment within the KwaZulu-Natal Midlands of southeastern South Africa, by combining geomorphic, hydrologic and geochemical fingerprinting analyses. The Mkabela Basin can be subdivided into three distinct subcatchments that differ in their ability to transport and store sediment along the axial valley. Headwater (upper catchment) areas are characterized by extensive wetlands that act as significant sediment sinks. Mid-catchment areas, characterized by higher relief and valley gradients, exhibit few wetlands, but rather are dominated by a combination of alluvial and bedrock channels that are conducive to sediment transport. The lower catchment exhibits a low-gradient alluvial channel that is boarded by extensive riparian wetlands that accumulate large quantities of sediment (and NPS pollutants). Fingerprinting studies suggest that silt- and clay-rich layers found within wetland and reservoir deposits are derived from the erosion of fine-grained, valley bottom soils frequently utilized as vegetable fields. Coarser-grained deposits within both wetlands and reservoirs result from the erosion of sandier hillslope soils extensively utilized for sugar cane, during relatively high magnitude runoff events that are capable of transporting sand-sized sediment off the slopes. Thus, the source of sediment to the axial valley varies as a function of sediment size and runoff magnitude. Sediment export from the basin was limited until the early 1990s, in part because the upper catchment wetlands were hydrologically disconnected from lower parts of the watershed during low- to moderate flood events. The construction of a drainage ditch through a previously unchanneled wetland altered the hydrologic connectivity of the catchment, allowing sediment to be transported from the headwaters to the lower basin where much of it was deposited within the riparian wetlands. The axial drainage system is now geomorphically and hydrologically connected during most events throughout the study basin. The study indicates that increased valley connectivity partly negated the positive benefits of controlling sediment/nutrient exports from the catchment by means of upland based, best management practices.

  18. Preliminary Basin Analysis of Latest Miocene Conglomerate Near Baha Kino, Coastal Sonora: A New Record of Crustal Deformation During Initial Opening of the Northern Gulf of California

    NASA Astrophysics Data System (ADS)

    Dorsey, R. J.; Peryam, T. C.; Bennett, S.; Oskin, M. E.; Iriondo, A.

    2008-12-01

    In coastal Sonora northwest of Baha Kino, we have initiated a basin-analysis study of nonmarine conglomerate (Tcg) that overlies and is locally interbedded with the 6.4-Ma Tuff of Mesa Cuadrada (Tmc). Tcg conglomerate is deeply eroded and cut by a complex set of syn- to post-basinal, N- to NNE-striking normal faults and NW-striking dextral strike-slip faults. We carried out detailed mapping and field descriptions, measured stratigraphic sections, and collected paleocurrent and clast-count data in Tcg. Zircons from the newly discovered Seri tuff near the base of the section, 160 m below Tmc, were dated using U-Pb SHRIMP geochronology at Stanford University. We obtained a 206Pb/238U weighted mean age of 6.53+/-0.18 Ma (n=14; MSWD=1.3), which yields a sediment-accumulation rate of 0.8+/-0.2 mm/yr for lower Tcg. Tcg is dominated by debris-flow facies consisting of massive, poorly sorted, weakly bedded, matrix-rich, pebble, cobble, to small-boulder conglomerate. A subsidiary sheet-flood facies is somewhat better sorted, generally lacks boulders, and contains weak but pervasive horizontal stratification. Both facies of Tcg record deposition in an alluvial fan environment. Well sorted and stratified stream deposits are conspicuously lacking. Preserved sections of Tcg range up to 170 to 240 meters thick in the southern part of the study area, and increase to at least 470 meters in the north where the Punta Chueca fault, a large NW-directed low-angle normal fault, apparently produced more extension and subsidence than smaller faults in the south. Clasts in Tcg are dominated by middle Miocene andesite, the 12.6-Ma Tuff of San Felipe, minor amounts of Tmc, and variable amounts of older basement rocks including tonalite, granodiorite, quartzite, metavolcanic rock, and a megacrystic K-spar-bearing granite that we have not seen in the local bedrock. After correcting for bedding dips and vertical-axis clockwise rotations determined from paleomagnetic analysis, restored paleocurrents reveal consistent overall transport to the SSW. We interpret Tcg to record deposition in a 10- to 20-km wide coastal belt of coalesced alluvial fans (bajadas) that formed on the margin of the nascent northern Gulf of California. Alluvial fans were likely derived from a large uplands source area NE of the Sacrificio fault that is now submerged beneath broad alluvial plains of the Rio Sonora. Prior to this time, between 12.5 and 6.5 Ma, extension caused tilting and erosion but did not produce significant crustal thinning or subsidence. The abrupt change to rapid subsidence and sedimentation in a belt of coastal alluvial fans records a major change in deformation style and crustal dynamics at about 6.5 Ma. We infer that this change coincides with the transition from pre-6.5 Ma diffuse regional extension (late Miocene proto-gulf stage) to rapid, localized latest Miocene oblique dextral shear that resulted from initiation or acceleration of plate-boundary strain in the northern Gulf of California. If this interpretation is correct, the onset of northern Gulf opening is thus dated at ca. 6.5 Ma.

  19. Runoff and solute mobilization processes in a semiarid headwater catchment

    NASA Astrophysics Data System (ADS)

    Hughes, Justin D.; Khan, Shahbaz; Crosbie, Russell S.; Helliwell, Stuart; Michalk, David L.

    2007-09-01

    Runoff and solute transport processes contributing to streamflow were determined in a small headwater catchment in the eastern Murray-Darling Basin of Australia using hydrometric and tracer methods. Streamflow and electrical conductivity were monitored from two gauges draining a portion of the upper catchment area (UCA) and a saline scalded area, respectively. Runoff in the UCA was related to the formation of a seasonally perched aquifer in the near-surface zone (0-0.4 m). A similar process was responsible for runoff generation in the saline scalded area. However, saturation in the scald area was related to the proximity of groundwater rather than low subsurface hydraulic conductivity. Because of higher antecedent water content, runoff commenced earlier in winter from the scald than did the UCA. Additionally, areal runoff from the scald was far greater than from the UCA. Total runoff from the UCA was higher than the scald (15.7 versus 3.5 mL), but salt export was far lower (0.6 and 5.4 t for the UCA and scald area, respectively) since salinity of the scald runoff was far higher than that from the UCA, indicating the potential impact of saline scalded areas at the catchment scale. End-member mixing analysis modeling using six solutes indicated that most runoff produced from the scald was "new" (40-71%) despite the proximity of the groundwater surface and the high antecedent moisture levels. This is a reflection of the very low hydraulic conductivity of soils in the study area. Nearly all chloride exported to the stream from the scald emanated from the near-surface zone (77-87%). Runoff and solute mobilization processes depend upon seasonal saturation occurring in the near-surface zone during periods of low evaporative demand and generation of saturated overland flow.

  20. Geohydrology, water quality, and preliminary simulations of ground-water flow of the alluvial aquifer in the Upper Black Squirrel Creek basin, El Paso County, Colorado

    USGS Publications Warehouse

    Buckles, D.R.; Watts, K.R.

    1988-01-01

    The upper Black Squirrel Creek basin in eastern El Paso County, Colorado, is underlain by an alluvial aquifer and four bedrock aquifers. Groundwater pumpage from the alluvial aquifer has increased since the mid-1950's, and water level declines have been substantial; the bedrock aquifers virtually are undeveloped. Groundwater pumpage for domestic, stock, agricultural, and municipal uses have exceeded recharge for the past 25 years. The present extent of the effect of pumpage on the alluvial aquifer was evaluated, and a groundwater flow model was used to simulate the future effect of continued pumpage on the aquifer. Measured water level declines from 1974 through 1984 were as much as 30 ft in an area north of Ellicott, Colorado. On the basis of the simulations, water level declines from October 1984 to April 1999 north of Ellicott might be as much as 20 to 30 ft and as much as 1 to 10 ft in most of the aquifer. The groundwater flow models provided a means of evaluating the importance of groundwater evapotranspiration at various stages of aquifer development. Simulated groundwater evapotranspiration was about 43% of the outflow from the aquifer during predevelopment stages but was less than 3% of the outflow from the aquifer during late-development stages. Analyses of 36 groundwater samples collected during 1984 indicated that concentrations of dissolved nitrite plus nitrate as nitrogen generally were large. Samples from 5 of the 36 wells had concentrations of dissolved nitrite plus nitrate as nitrogen that exceeded drinking water standards. Water from the alluvial aquifer generally is of suitable quality for most uses. (USGS)

  1. Coal gas openhole completion well effectiveness in the Piceance Basin, Colorado: Preliminary results, South Shale Ridge [number sign]11-15 well

    SciTech Connect

    Close, J.C. ); Dowden, D. )

    1992-01-01

    Since 1983, the Deep Coal Seam Project (DCSP) and the Western Cretaceous Coal Seam Project (WCCSP) of the Gas Research institute has funded research efforts in the Piceance and San Juan basins of Colorado and New Mexico to further the knowledge of all facets of commercial coalbed natural gas reservoir development. Because of WCCSP research into openhole completion well effectiveness in the Fruitland play, and the need to complete a successful Cameo coal openhole well, the South Shale Ridge [number sign]11-15 well was deemed to be an excellent chance for technology transfer and evaluation. Because of implementation of carefully designed air mist drilling and controlled openhole completion techniques, along with a sufficient magnitude of cleat permeability, it appears that the [number sign]11-15 well is commercial. The cavity was installed without major problems. The initial gas production test rate of roughly 280 MCFGPD is one of the best in South Shale Ridge. The [number sign]11-15 well case study is quite important in that it may serve to emphasize the point that the conservative attitude towards commercialization of previously untapped petroleum resources is often not correct. It is now an open question as to whether the conventional wisdom that most of the Cameo coal gas play is too tight to enable commercial production is indeed true, or if by analogy with Fruitland openhole wells, Cameo coal wells that have been hydraulic fracture stimulated are commonly very poorly connected to the cleat permeability of the reservoir. There is no significant reason to believe that the South Shale Ridge area is geologically unique, and thus there is a distinct possibility that more widespread Cameo coal production than has been previously recorded can be achieved.

  2. Catchment similarity and classification in areas of high hydrologic gradients: the case of Chilean Patagonia

    NASA Astrophysics Data System (ADS)

    Dussaillant, A.; Buytaert, W.; Maturana, O.; Arias, M.

    2009-04-01

    The Baker River Basin is located in Patagonia, Southern South America, with a total drainage area of 26,726 km2 (second-largest river basin in Chile). The Baker River has the highest mean annual discharge rate of all Chilean rivers (1,133 m3/s), and flows out of Bertrand Lake, which in turn receives the draining waters from the General Carrera Lake (surface area of about 1800 km2, Latin America's second largest). Geology and climate gradients are even more extreme than in the rest of the country, from mountain to sea, and sometimes having mean annual rainfalls change from 8000 mm to 400 mm in less than 60 km. Bigger basins, like the Baker, have Eastern sub-basins with even a semi-arid character, whereas Western sub-catchments drain from ice fields. Thus, flow regimes may have very diverse characters in combination. And regarding sediment, although many rivers are born in lakes (many bi-national), they have important profile slopes and plenty of sediment available (partly due to glacial deposits). In spite of this huge natural variability, there is scant data due to low resources and remoteness: few meteorological and flow stations (having few decades or much shorter data series), and lack of stations in Western areas, linked to mountainous terrain, glaciers, and the ice fields. Nevertheless, decisions are being made with what seems extremely limited hydro-meteorological, streamflow, and in general, river data. In fact, Chile is currently in a crossroad due to mega projects being planned in Aysén, Chilean Patagonia (at least 5 hydropower dams producing more than 2000 MW). We characterize streamflows for ungauged basins, such as floods, mean annual flows, and flow duration curves, which can then be used related to a more sustainable design and operation of dams for hydropower. Relations extracted from gauged catchments to their geomorphologic characteristics and indices will be used to transfer those relations to ungauged catchments.

  3. Natural phosphorus and dry matter loading from clayey boreal catchments in Finland

    NASA Astrophysics Data System (ADS)

    Mäkinen, J.; Tammelin, M.; Kauppila, T.

    2012-04-01

    Lake management design and water quality modeling utilize data on diffuse nutrient export from catchments to the receiving lakes. Background nutrient export estimation from fine-grained soils requires examination of catchments in their natural state. However, Finnish fine-grained soils are mainly cultivated or otherwise utilized, which makes the estimation challenging. For this reason the study aimed to model the natural levels of dry matter and phosphorus loading from the catchment based on lake sediments that accumulated before significant human action. The study lakes were selected based on three main criteria: 1) Ratio of 1/10 between lake and catchment size was set as target. 2) simple lake basin morphology: round-shaped with a flat bottom, 3) The percentage range of fine grained materials within the catchment was as wide as possible so that a sufficient composition gradient was obtained. A total of 22 lakes with sizes ranging between 15 and 1 242 ha were selected from Southern Finland. Natural lake water phosphorus concentration was inferred with diatom-based modeling utilizing biotic assemblages from sediment that accumulated before human impact. The inferred concentration varied between 12 and 79 µg/l. There is some bias in the inferred values due to model properties that result in overestimation of the lowest phosphorus concentrations. The results suggest that natural lake water phosphorus content increases as sediment grain size decreases. However, sediment phosphorus concentrations decrease as well. Natural and recent (1986 - 2011) dry matter accumulations were compared by dating the samples with 14C and 137Cs methods. The accumulation results were 16 - 217 g/m2/a and 346 - 2626 g/m2/a respectively. Dry matter accumulation increased as the sediment grain size decreased, counteracting the influence of decreasing sedimentary phosphorus concentrations on net accumulation of phosphorus in the basin.

  4. Temporal inequality in catchment discharge and solute export

    NASA Astrophysics Data System (ADS)

    Jawitz, James W.; Mitchell, Jennifer

    2011-10-01

    A framework is developed for characterizing the temporal inequality of stream discharge and solute loads to receiving waters using Lorenz diagrams and the associated Gini coefficient, G. These descriptors are used to illustrate a broad range of observed flow variability with a synthesis of multidecadal flow data from 22 rivers in Florida. Multidecadal phosphorus load data from four of the primary tributaries to Lake Okeechobee, Florida, and sodium and nitrate load data from nine of the Hubbard Brook, New Hampshire, long-term study site catchments are used to examine the relation between the inequality of flow and load. The intra-annual loads to Lake Okeechobee are shown to be highly unequal, such that 90% of the annual load is delivered in as little as 15% of the time. Analytic expressions are developed for measures of inequality in terms of parameters of the lognormal distribution under general conditions that include periods of zero flow. In cases where variability of concentrations is low compared to that of flows (chemostatic conditions), such as for phosphorus in the Lake Okeechobee basin and sodium in Hubbard Brook, the temporal inequality of flow is a strong surrogate for load inequality. However, in cases where variability of concentrations is high compared to that of flows (chemodynamic conditions), such as for nitrate in the Hubbard Brook catchments, load inequality is greater than flow inequality. The measured degree of correspondence between flow and load inequality for these data sets is shown to be well described using the general inequality framework introduced here.

  5. Morphometric properties of the trans-Himalayan river catchments: Clues towards a relative chronology of orogen-wide drainage integration

    NASA Astrophysics Data System (ADS)

    Ghosh, Parthasarathi; Sinha, Sayan; Misra, Arindam

    2015-03-01

    The geomorphological evolution of the Himalayan mountain belt both in terms of crustal deformation and concomitant erosion by surface processes has been suggested to have a profound influence on a number of earth system processes and has been extensively researched through a number of different techniques. The huge catchments of the trans-Himalayan rivers are the product of long-term fluvial erosion of the landscape. This work attempts to understand their evolution through a study of drainage network, morphology, and internal organization of the smaller watersheds nested within each catchment. Using morphometric techniques applied to an orogen-wide digital elevation data grid, we characterized the drainage network structure and catchment of all the 18 trans-Himalayan rivers situated between the exits of the Indus and Brahmaputra rivers and constructed rectangular approximations of the catchment geometries. With the help of catchment dimensions measured transverse and parallel to the strike of the orogen, and by analyzing the dimension and spatial dispositions of the rectangular approximations, we demonstrate that the trans-Himalayan catchment shapes cannot be explained only as a product of the headward enlargement of drainage networks on a topographic slope, or orogenic taper. Within individual catchments we identified the existence of drainage components (watersheds) that are organized in a systematic manner with respect to the first-order physiographic features of the Himalayas, formed at different periods of geological time. Each of them shows distinct morphometric characteristics that are indicative of differences in processes and / or time scale involved in their formation. The hypsometric properties of the watersheds occupying the upper part of the catchments suggest that they are the remnants of pre-orogenic drainage that became confined to the leeward side of the Himalayas before the advent of monsoon circulation. The shape and organization of the transverse watersheds occurring in the middle of the catchments resemble a series of small drainage basins formed on the precursor topography of the modern Himalayas. The lower parts of the catchments were shaped instead by drainage diversions induced by deformations related to the frontal thrust. We show how the shape of the catchments represents an integration of processes such as headward drainage enlargement, capture of pre-existing drainage, and diversion of drainage in response to crustal deformation at successive stages of Himalayan mountain growth. We further show that there is a systematic change in the morphological characters and organization of the watersheds, nested in the catchments, from the middle towards the flanks of the Himalayas indicating the variations in relative influence of different drainage evolution processes and the orogen-scale heterogeneity in tectonic style.

  6. Integration of sewer system maps in topographically based sub-basin delineation in suburban areas

    NASA Astrophysics Data System (ADS)

    Jankowfsky, Sonja; Branger, Flora; Braud, Isabelle; Rodriguez, Fabrice

    2010-05-01

    Due to the increase of urbanization, suburban areas experience a fast change in land use. The impact of such modifications on the watershed hydrological cycle must be quantified. To achieve this goal, distributed hydrological models offer the possibility to take into account land use change, and more particularly to consider urbanized areas and anthropogenic features such as roads or ditches and their impact on the hydrological cycle. A detailed definition of the hydrographical drainage network and a corresponding delineation of sub-basins is therefore necessary as input to distributed models. Sub-basins in natural catchments are usually delineated using standard GIS based terrain analysis. The drainage network in urbanised watersheds is often modified, due to sewer systems, ditches, retention basins, etc.. Therefore, its delineation is not only determined by topography. The simple application of terrain analysis algorithms to delineate sub-basins in suburban areas can consequently lead to erroneous sub-basin borders. This study presents an improved approach for sub-basin delineation in suburban areas. It applies to small catchments connected to a sewage plant, located outside the catchment boundary. The approach assumes that subsurface flow follows topography. The method requires a digital elevation model (DEM), maps of land use, cadastre, sewer system and the location of measurement stations and retention basins. Firstly, the topographic catchment border must be defined for the concerning flow measurement station. Standard GIS based algorithms, like the d8-flow direction algorithm (O'Callaghan and Mark, 1984) can be applied using a high resolution DEM. Secondly, the artificial catchment outlets have to be determined. Each catchment has one natural outlet - the measurement station on the river- but it can have several artificial outlets towards a sewage station. Once the outlets are determined, a first approximation of the "theoretical maximal contributing area" can be made. It encompasses the whole connected sewer system and the topographic catchment boundary. The area of interest is therefore defined. The next step is the determination of the extended drainage network, consisting of the natural river, ditches, combined and separated sewer systems and retention basins. This requires a detailed analysis of sewer system data, field work (mapping of ditches and inlets into the natural river). Contacts with local authorities are also required to keep up-to-date about recent changes. Pure wastewater and drinking water pipes are not integrated in the drainage network. In order to have a unique drainage network for the model, choices might have to be made in case of several coexisting drainage pipes. The urban sub-basins are then delineated with the help of a cadastral map (Rodriguez et al., 2003) or an aerial photography. Each cadastral unit is connected to the closest drainage pipe, following the principle of proximity and gravity. The assembly of all cadastral units connected to one network reach represents one urban sub-basin. The sub-basins in the rural part are calculated using the d8 flow direction and watershed delineation algorithm with "stream burning" (Hutchinson, 1989). One sub-basin is delineated for each reach of the extended drainage network. Some manual corrections of the calculated sub-basins are necessary. Finally, the urban and rural sub-basins are merged by subtraction of the urban area from the rural area and subsequent union of both maps. This method was applied to the Chaudanne catchment, a sub-basin of the Yzeron catchment (ca. 4 km2) in the suburban region of Lyon city, France. The method leads to a 30 % extended catchment area, as compared to the topographic catchment area. For each river inlet the sub-basin area could be determined, as well as for each retention basin. This information can be directly used for the dimensioning of retention basins, pipe diameters, etc.

  7. Data-based information gain on the response behaviour of hydrological models at catchment scale

    NASA Astrophysics Data System (ADS)

    Willems, Patrick

    2013-04-01

    A data-based approach is presented to analyse the response behaviour of hydrological models at the catchment scale. The approach starts with a number of sequential time series processing steps, applied to available rainfall, ETo and river flow observation series. These include separation of the high frequency (e.g., hourly, daily) river flow series into subflows, split of the series in nearly independent quick and slow flow hydrograph periods, and the extraction of nearly independent peak and low flows. Quick-, inter- and slow-subflow recession behaviour, sub-responses to rainfall and soil water storage are derived from the time series data. This data-based information on the catchment response behaviour can be applied on the basis of: - Model-structure identification and case-specific construction of lumped conceptual models for gauged catchments; or diagnostic evaluation of existing model structures; - Intercomparison of runoff responses for gauged catchments in a river basin, in order to identify similarity or significant differences between stations or between time periods, and relate these differences to spatial differences or temporal changes in catchment characteristics; - (based on the evaluation of the temporal changes in previous point:) Detection of temporal changes/trends and identification of its causes: climate trends, or land use changes; - Identification of asymptotic properties of the rainfall-runoff behaviour towards extreme peak or low flow conditions (for a given catchment) or towards extreme catchment conditions (for regionalization, ungauged basin prediction purposes); hence evaluating the performance of the model in making extrapolations beyond the range of available stations' data; - (based on the evaluation in previous point:) Evaluation of the usefulness of the model for making extrapolations to more extreme climate conditions projected by for instance climate models. Examples are provided for river basins in Belgium, Ethiopia, Kenya, Ecuador, Bolivia and China. References: Van Steenbergen, N., Willems, P. (2012), 'Method for testing the accuracy of rainfall-runoff models in predicting peak flow changes due to rainfall changes, in a climate changing context', Journal of Hydrology, 414-415, 425-434, doi:10.1016/j.jhydrol.2011.11.017 Mora, D., Willems, P. (2012), 'Decadal oscillations in rainfall and air temperature in the Paute River Basin - Southern Andes of Ecuador', Theoretical and Applied Climatology, 108(1), 267-282, doi:0.1007/s00704-011-0527-4 Taye, M.T., Willems, P. (2011). 'Influence of climate variability on representative QDF predictions of the upper Blue Nile Basin', Journal of Hydrology, 411, 355-365, doi:10.1016/j.jhydrol.2011.10.019 Taye, M.T., Willems, P. (2012). 'Temporal variability of hydro-climatic extremes in the Blue Nile basin', Water Resources Research, 48, W03513, 13p. Vansteenkiste, Th., Tavakoli, M., Ntegeka, V., Willems, P., De Smedt, F., Batelaan, O. (in press), 'Climate change impact on river flows and catchment hydrology: a comparison of two spatially distributed models', Hydrological Processes; doi: 10.1002/hyp.9480 [in press

  8. Impact of earthquake-triggered landslides on catchment sediment yield

    NASA Astrophysics Data System (ADS)

    Vanmaercke, M.; Obreja, F.; Poesen, J.

    2015-03-01

    This study explores the role of seismic activity in explaining spatial and temporal variation in sediment export from the Siret basin in Romania. Based on long-term (>30 years) sediment export measurements for 38 subcatchments, we found that spatial variation in sediment yield (SY) is strongly correlated to the degree of seismic activity and catchment lithology. Combined, these factors explain 80% of the variation in SY. To investigate the role of earthquake-triggered landslides in explaining these correlations, we studied the temporal variability in sediment concentrations before and after the 7.4 Mw earthquake of 1977 for ten subcatchments. Despite the fact that this earthquake triggered many landslides, only one subcatchment showed a clear (3-fold) increase in sediment concentration per unit discharge after the earthquake. This shows that, although prolonged seismic activity strongly controls average SY, individual earthquakes do not necessarily affect sediment export at short timescales.

  9. Parsimonious hydrological modeling of urban sewer and river catchments

    NASA Astrophysics Data System (ADS)

    Coutu, Sylvain; Del Giudice, Dario; Rossi, Luca; Barry, D. A.

    2012-09-01

    SummaryA parsimonious model of flow capable of simulating flow in natural/engineered catchments and at WWTP (Wastewater Treatment Plant) inlets was developed. The model considers three interacting, dynamic storages that account for transfer of water within the system. One storage describes the “flashy” response of impervious surfaces, another pervious areas and finally one storage describes subsurface flow. The sewerage pipe network is considered as an impervious surface and is thus included in the impervious surface storage. In addition, the model assumes that water discharged from several CSOs (combined sewer overflows) can be accounted for using a single, characteristic CSO. The model was calibrated on, and validated for, the Vidy Bay WWTP, which receives effluent from Lausanne, Switzerland (population about 200,000), as well as for an overlapping urban river basin. The results indicate that a relatively simple approach is suitable for predicting the responses of interacting engineered and natural hydrosystems.

  10. Quantifying denudation rates in Mediterranean margin catchments: the Gulf of Lion and East-Corsica case-study

    NASA Astrophysics Data System (ADS)

    Molliex, S.; Rabineau, M.; Jouet, G.; Bourles, D. L.; Freslon, N.; Leroux, E.; Moreau, J.; Aslanian, D.; Vella, C.

    2013-12-01

    Margins are the place of transfer, deposit and erosion of sediments whose geometries are controlled by sea-level fluctuations, vertical movements and sedimentary fluxes. Surface processes (sedimentation, denudation) and deep-sea dynamic are also intimately linked. Due to the numerous data acquired over the last 10 years, the Gulf of Lion and East-Corsica margins could be considered as privileged studied areas to understand the relationships between denudation, sedimentation and associated vertical displacements. The quantification of denudation rates on these margins catchments, using offshore and onshore data aims to improve the understanding of the temporal and spatial evolution of denudation processes in their sedimentation and geodynamic evolution in a large basin (Gulf of Lion) and in a small confined basin (Golo margin; East-Corsica) during the Quaternary. The Gulf of Lion is the northern passive margin of the Liguro-provenal basin, in western Mediterranean Sea. During the Quaternary, it receives sediments from catchments draining several structural domains, as Alps, Pyrenees and Massif Central, for a drainage area of about 120,000 km^2. The East-Corsica corresponds to the western passive margin of the Tyrrhenian basin. The main catchment (Golo River) size is about 100 times smaller than the Gulf of Lion and is composed by two main structural units: Hercynian granites in the upstream part and Alpine schists in the downstream part. In this study, we quantified Quaternary denudation rates using four independent methods: i) estimation of eroded volumes using DEMs; ii) compilation of present-day sediment load fluxes; iii) determination of catchment-scale cosmogenic denudation rate by measuring 10Be concentrations in sands at the catchment outlets or buried in boreholes; iv) quantification of sediment volumes deposited offshore. Our results show a good consistence between the four methods. The Inner Alps present the highest values of denudation (~ 700 m/Ma), compared to averaged much lower values in other domains (150-250 m/Ma in foreland Alps, 100-150 m/Ma in Corsica, about 100 m/Ma in Pyrenees and 55-75 m/Ma in Massif Central). The alpine domain provides at least 75 % of the eroded volume in the Gulf of Lion catchment. A quantitative geomorphologic approach highlights the main role of denudation processes in relief evolution for both studied areas. At a regional scale (Gulf of Lion catchment), we highlight an exponential correlation between mean catchment elevation and denudation rates suggesting the main role of uplift in areas glaciated during the LGM in the control of denudation rates. At a more local scale (East-Corsica), denudation rates seem to rely on lithologic and structural control.

  11. Erosion rates in the Rio La Paz drainage basin: evidence for spatially and temporally variable erosion processes

    NASA Astrophysics Data System (ADS)

    Zeilinger, G.; Kober, F.; Strecker, M.; Ivy-Ochs, S.; Kubik, P. W.; Hippe, K.

    2009-04-01

    With a total drainage area of 4850 km2 the morphometry of the La Paz drainage basin in the Bolivian Altiplano results from a combination of feedback mechanisms involving erosion and crustal bending. Apart from the Rio Consata the Rio de La Paz constitutes the only drainage system sourced on the Altiplano that cuts across the eastern Altiplano boundrary in the Cordillera Real and links this region with Amazonia. The fluvial network therefore connects geomorphically and geologically very different zones: 1) the virtually flat Altiplano with its Mio-Pliocene fluvio-lacustrine deposits and volcanics, 2) the high Cordillera, mainly comprised of Paleozoic metasediments, Mesozoic plutons, and Miocene volcanics, and 3) the folded sedimentary rocks of foothills of the Subandean zone. Cross-cutting relationships between dated strata and incised valleys indicate that incision in the Rio La Paz headwaters postdates 5 Ma, and possibly even 2.8 Ma. The volume of about 3950 km3, which has been evacuated since then (assuming 2.8 Ma as starting point of incision) by the Rio La Paz drainage system to the Rio Beni relates to an average erosion rate of 290 mm/ky. In order to investigate this long-term erosion rate with respect to possible spatial and temporal variations, we studied catchment-wide erosion rates in the Rio La Paz basin and contributing areas of adjacent subbasins using terrestrial cosmogenic nuclides (TCN). This method allows the determination of catchment-wide erosion rates from sediments being currently exported from the basin over timescales ranging from 1-10ky. Our preliminary results reveal an erosion rate of 230 mm/ky for the entire Rio La Paz basin (sample from basin outlet). Subbasin erosion rates vary from ca. 100 up to 600 mm/ky. So far, no direct correlation of mean slopes (and other morphometric parameters) in the subbasins and their respective erosion rates are obvious. However, there is a trend that the subbasins with high erosion rates are located close to the Cordillera, whereas subbasins with low erosion rates are located in immediate vicinity of the Altiplano. Present-day erosion rates in the Rio La Paz catchment obtained for a time frame spanning a decade range from 600-6000 mm/ky, based on sediment-yield data from published data, which is significantly higher than the ones revealed with TCN and the long-term volume estimates. The strong increase in the most recent erosion rates is most likely caused by human land-use practices (e.g. deforestation). The different roles of erosion processes (e.g. headwater expansion by landsliding and / or fluvial incision) and relief might be a cause for spatially variable erosion rates. In contrast, on the Altiplano west of the Rio La Paz drainage divide, erosion rates are one to two orders of magnitude lower than in the Rio La Paz catchment (Hippe et al. in prep.). In summary, the TCN results from the interior parts of the Rio La Paz catchments indicate spatially and temporally variable climatic and tectonic signals along the margins of Earth's second largest plateau.

  12. Impact of papyrus wetland encroachment on spatial and temporal variabilities of stream flow and sediment export from wet tropical catchments.

    PubMed

    Ryken, N; Vanmaercke, M; Wanyama, J; Isabirye, M; Vanonckelen, S; Deckers, J; Poesen, J

    2015-04-01

    During the past decades, land use change in the Lake Victoria basin has significantly increased the sediment fluxes to the lake. These sediments as well as their associated nutrients and pollutants affect the food and water security of millions of people in one of Africa's most densely populated regions. Adequate catchment management strategies, based on a thorough understanding of the factors controlling runoff and sediment discharge are therefore crucial. Nonetheless, studies on the magnitude and dynamics of runoff and sediment discharge are very scarce for the Lake Victoria basin and the African Rift region. We therefore conducted runoff discharge and sediment export measurements in the Upper Rwizi, a catchment in Southwest Uganda, which is representative for the Lake Victoria basin. Land use in this catchment is characterized by grazing area on the high plateaus, banana cropping on the slopes and Cyperus papyrus L. wetlands in the valley bottoms. Due to an increasing population pressure, these papyrus wetlands are currently encroached and transformed into pasture and cropland. Seven subcatchments (358 km2-2120 km2), with different degrees of wetland encroachment, were monitored during the hydrological year June 2009-May 2010. Our results indicate that, due to their strong buffering capacity, papyrus wetlands have a first-order control on runoff and sediment discharge. Subcatchments with intact wetlands have a slower rainfall-runoff response, smaller peak runoff discharges, lower rainfall-runoff ratios and significantly smaller suspended sediment concentrations. This is also reflected in the measured annual area-specific suspended sediment yields (SYs): subcatchments with encroached papyrus swamps have SY values that are about three times larger compared to catchments with intact papyrus vegetation (respectively 106-137 ton km(-2) y(-1) versus 34-37 ton km(-2) y(-1)). We therefore argue that protecting and (where possible) rehabilitating these papyrus wetlands should be a corner stone of catchment management strategies in the Lake Victoria basin. PMID:25617700

  13. Integrated flow and temperature modeling at the catchment scale

    NASA Astrophysics Data System (ADS)

    Loinaz, Maria C.; Davidsen, Hasse Kampp; Butts, Michael; Bauer-Gottwein, Peter

    2013-07-01

    Changes in natural stream temperature levels can be detrimental to the health of aquatic ecosystems. Water use and land management directly affect the distribution of diffuse heat sources and thermal loads to streams, while riparian vegetation and geomorphology play a critical role in how thermal loads are buffered. In many areas, groundwater flow is a significant contribution to river flow, particularly during low flows and therefore has a strong influence on stream temperature levels and dynamics. However, previous stream temperature models do not properly simulate how surface water-groundwater dynamics affect stream temperature. A coupled surface water-groundwater and temperature model has therefore been developed to quantify the impacts of land management and water use on stream flow and temperatures. The model is applied to the simulation of stream temperature levels in a spring-fed stream, the Silver Creek Basin in Idaho, where stream temperature affects the populations of fish and other aquatic organisms. The model calibration highlights the importance of spatially distributed flow dynamics in the catchment to accurately predict stream temperatures. The results also show the value of including temperature data in an integrated flow model calibration because temperature data provide additional constraints on the flow sources and volumes. Simulations show that a reduction of 10% in the groundwater flow to the Silver Creek Basin can cause average and maximum temperature increases in Silver Creek over 0.3 C and 1.5 C, respectively. In spring-fed systems like Silver Creek, it is clearly not feasible to separate river habitat restoration from upstream catchment and groundwater management.

  14. Water Catchment and Storage Monitoring

    NASA Astrophysics Data System (ADS)

    Bruenig, Michael; Dunbabin, Matt; Moore, Darren

    2010-05-01

    Sensors and Sensor Networks technologies provide the means for comprehensive understanding of natural processes in the environment by radically increasing the availability of empirical data about the natural world. This step change is achieved through a dramatic reduction in the cost of data acquisition and many orders of magnitude increase in the spatial and temporal granularity of measurements. Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) is undertaking a strategic research program developing wireless sensor network technology for environmental monitoring. As part of this research initiative, we are engaging with government agencies to densely monitor water catchments and storages, thereby enhancing understanding of the environmental processes that affect water quality. In the Gold Coast hinterland in Queensland, Australia, we are building sensor networks to monitor restoration of rainforest within the catchment, and to monitor methane flux release and water quality in the water storages. This poster will present our ongoing work in this region of eastern Australia. The Springbrook plateau in the Gold Coast hinterland lies within a World Heritage listed area, has uniquely high rainfall, hosts a wide range of environmental gradients, and forms part of the catchment for Gold Coast's water storages. Parts of the plateau are being restored from agricultural grassland to native rainforest vegetation. Since April 2008, we have had a 10-node, multi-hop sensor network deployed there to monitor microclimate variables. This network will be expanded to 50-nodes in February 2010, and to around 200-nodes and 1000 sensors by mid-2011, spread over an area of approximately 0.8 square kilometers. The extremely dense microclimate sensing will enhance knowledge of the environmental factors that enhance or inhibit the regeneration of native rainforest. The final network will also include nodes with acoustic and image sensing capability for monitoring higher level parameters such as fauna diversity. The regenerating rainforest environment presents a number of interesting challenges for wireless sensor networks related to energy harvesting and to reliable low-power wireless communications through dense and wet vegetation. Located downstream from the Springbrook plateau, the Little Nerang and Hinze dams are the two major water supply storages for the Gold Coast region. In September 2009 we fitted methane, light, wind, and sonar sensors to our autonomous electric boat platform and successfully demonstrated autonomous collection of methane flux release data on Little Nerang Dam. Sensor and boat status data were relayed back to a human operator on the shore of the dam via a small network of our Fleck™ nodes. The network also included 4 floating nodes each fitted with a string of 6 temperature sensors for profiling temperature at different water depths. We plan to expand the network further during 2010 to incorporate floating methane nodes, additional temperature sensing nodes, as well as land-based microclimate nodes. The overall monitoring system will provide significant data to understand the connected catchment-to-storage system and will provide continuous data to monitor and understand change trends within this world heritage area.

  15. Going With the Flow: Participatory Action Research and River Catchment Management