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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

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

    SciTech Connect

    Nimz, G. J., LLNL

    1998-06-01

    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.

  3. [Molecular-phylogenetic analysis of cyclopoids (Copepoda: Cyclopoida) from Lake Baikal and its water catchment basin].

    PubMed

    Maĭor, T Iu; Sheveleva, N G; Sukhanova, L V; Timoshkin, O A; Kiril'chik, S V

    2010-11-01

    Baikalian cyclopoids represent one of the richest endemic faunas of freshwater cyclopoid copepods. The genus Diacyclops Kiefer, 1927 is the most numerous by species number in the lake. In this work, molecular-phylogenetic analysis of 14 species and 1 sub-species from Lake Baikal and its water catchment basin is performed. The regions of mitochondrial cytochrom-oxydase I (COI) and of nuclear small-subunit 18S rRNA were used as evolution markers. In the obtained set of nucleotide sequences of COT gene, an effect of synonymous substitution saturation is revealed. Baikalian representatives of the genus Diacyclops form at phylogenetic schemes by two markers a monophyletic griup, it suggest their origin from a common ancestral form. Preliminary estimate of the age of this group is 20-25 My.

  4. The "Teflon basin" myth: Snow-soil interactions in mountain catchments in the western US

    NASA Astrophysics Data System (ADS)

    Williams, M. W.; Cowie, R. M.

    2015-12-01

    In much of western North America, snow and snowmelt provide the primary means for storage of winter precipitation, effectively transferring water from the relatively wet winter season to the typically dry summers. A common assumption is that high-elevation catchments in the western United States behave like "Teflon basins" and that water released from seasonal storage in snow packs flows directly into streams with little or no interaction with underlying soils. Here I present information from a variety of catchments in the Colorado Front Range on snowmelt/soil interactions using isotopic, geochemical, nutrient and hydrometric data in 2- and 3- component hydrograph separations, along with end-member mixing analysis (EMMA). For most catchments we measured these parameters in weekly precipitation, the seasonal snowpack, snowmelt before contact with the ground, discharge, springs, soil solution, and groundwater. We ran EMMA at the catchment scale for catchments that represent the rain-snow transition zone in the montane forest, the seasonally snow covered sub-alpine to alpine transition zone, and a high-elevation alpine zone near the continental divide. In all catchments three end-members were the source waters for about 95% of discharge. Two end-members were the same in all catchments, snow and groundwater. For the alpine catchment talus springs was the third water source, while rain was the third water source in the two lower-elevation catchments. For all three catchments, soil solution plotted with stream waters along or near a line connecting the snow and groundwater end-members. Thus, for seasonally snow-covered catchments from montane to alpine ecosystems, snowmelt infiltrates underlying soils before snowmelt recharges groundwater reservoirs and contributes to surface flows. Seasonally snow-covered catchments are not Teflon basins. Rather, snowmelt infiltrates soils where solute concentrations are changed by biological and geochemical processes.

  5. Impacts of Climate Change on Groundwater Recharge and Streamflow in Headwater Catchments in the Yakima River Basin

    NASA Astrophysics Data System (ADS)

    Nguyen, T. T.; Adam, J. C.

    2015-12-01

    Headwater catchments are important sources of surface water supply, groundwater recharge and, thus, groundwater supply for agricultural activities in the Yakima River Basin (YRB, one of the most important agricultural basins in the western U.S). These catchments are, however, vulnerable to projected climate change in future decades, particularly if their runoff is dominated by snowmelt. The goal of this study is to assess the potential impacts of climate change on the temporal and spatial distributions of groundwater recharge and streamflow in three headwater catchments in the YRB. A Regional Hydro-Ecologic Simulation System ("RHESSys") is calibrated and evaluated with a global optimization tool ("Covariance Matrix Adaptation Evolution Strategy - CMA-ES") using 27 years of observation data from 1979 to 2005. Statistically downscaled climate projections for the 2050s from four global climate models driven by two different representative concentration pathways, RCP4.5 and RCP8.5 are used to predict future hydrologic changes. Our preliminary results show an increase in annual recharge between 2% and 13%, as well as in streamflow between 1% and 17%. Seasonal changes of recharge and streamflow are more pronounced with an increase up to 210% in winters and a decrease as high as 60% in summers in the 2050s. Both recharge and streamflow projections indicate timing shifts in all three catchments. The outcome from this study will be an integral part of a future study which investigates the impacts of climate change on surface water vulnerability due to supplemental pumping, potential recharge changes and related surface-groundwater interactions in the YRB using an integrated modeling approach that consists of three models: RHESSys, a groundwater model (MODFLOW) and a river and reservoir management model (RiverWare).

  6. Complex networks, community structure, and catchment classification in a large-scale river basin

    NASA Astrophysics Data System (ADS)

    Fang, Koren; Sivakumar, Bellie; Woldemeskel, Fitsum M.

    2017-02-01

    This study introduces the concepts of complex networks, especially community structure, to classify catchments in large-scale river basins. The Mississippi River basin (MRB) is considered as a representative large-scale basin, and daily streamflow from a network of 1663 stations are analyzed. Six community structure methods are employed: edge betweenness, greedy algorithm, multilevel modularity optimization, leading eigenvector, label propagation, and walktrap. The influence of correlation threshold (i.e. spatial correlation in flow between stations) on classification (i.e. community formation) is examined. The consistency among the methods in classifying catchments is assessed, using a normalized mutual information (NMI) index. An attempt is also made to explain the community formation in terms of river network/branching and some important catchment/flow properties. The results indicate that the correlation threshold has a notable influence on the number and size of communities identified and that there is a high level of consistency in the performance among the methods (except for the leading eigenvector method at lower thresholds). The results also reveal that only a few communities combine to represent a majority of the catchments, with the 10 largest communities (roughly 4% of the total number of communities) representing almost two-thirds of the catchments. Community formation is found to be influenced not only by geographic proximity but also, more importantly, by the organization of the river network (i.e. main stem and subsequent branching). Some communities are found to exhibit a greater variability in catchment/flow properties within themselves when compared to that of the whole network, thus indicating that such characteristics are unlikely to be a significant influence on community grouping.

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  8. Spatial moments of catchment rainfall: rainfall spatial organisation, basin morphology, and flood response

    NASA Astrophysics Data System (ADS)

    Zoccatelli, D.; Borga, M.; Viglione, A.; Chirico, G. B.; Blöschl, G.

    2011-12-01

    This paper describes a set of spatial rainfall statistics (termed "spatial moments of catchment rainfall") quantifying the dependence existing between spatial rainfall organisation, basin morphology and runoff response. These statistics describe the spatial rainfall organisation in terms of concentration and dispersion statistics as a function of the distance measured along the flow routing coordinate. The introduction of these statistics permits derivation of a simple relationship for the quantification of catchment-scale storm velocity. The concept of the catchment-scale storm velocity takes into account the role of relative catchment orientation and morphology with respect to storm motion and kinematics. The paper illustrates the derivation of the statistics from an analytical framework recently proposed in literature and explains the conceptual meaning of the statistics by applying them to five extreme flash floods occurred in various European regions in the period 2002-2007. High resolution radar rainfall fields and a distributed hydrologic model are employed to examine how effective are these statistics in describing the degree of spatial rainfall organisation which is important for runoff modelling. This is obtained by quantifying the effects of neglecting the spatial rainfall variability on flood modelling, with a focus on runoff timing. The size of the study catchments ranges between 36 to 982 km2. The analysis reported here shows that the spatial moments of catchment rainfall can be effectively employed to isolate and describe the features of rainfall spatial organization which have significant impact on runoff simulation. These statistics provide useful information on what space-time scales rainfall has to be monitored, given certain catchment and flood characteristics, and what are the effects of space-time aggregation on flood response modeling.

  9. Variability of extreme events in the Colombian Pacific and Caribbean catchment basins

    NASA Astrophysics Data System (ADS)

    Hoyos, Isabel; Baquero-Bernal, Astrid; Jacob, Daniela; Rodríguez, Boris A.

    2013-04-01

    This paper analyses the behavior of extreme events of surface precipitation and temperature inside the Pacific and Caribbean Catchment Basins in Colombia using several datasets such as observations, reconstructed data, NCEP-NCAR and ERA-40 reanalyses and data from the regional model REMO. We use an extreme value method that selects the time series excesses over a nonstationary threshold and adjusts them to a generalized Pareto distribution. The goodness of fit is evaluated through a test that includes the Cramer-von Mises, Kolmogorov-Smirnov and Anderson-Darling statistics and the p values generated by parametric bootstrap resampling. The test not only evaluates the goodness of fit but also the threshold choice. The parameters are presented in maps that allow recognition of the features of the extreme behaviour inside the catchment basins, and differences and similarities between them. Maps of return periods for the maximum extreme events are also presented. A strong influence of the El Niño-Southern oscillation on the extreme events of both temperature and precipitation is found in the two catchment basins.

  10. Variability of rainfall over Lake Kariba catchment area in the Zambezi river basin, Zimbabwe

    NASA Astrophysics Data System (ADS)

    Muchuru, Shepherd; Botai, Joel O.; Botai, Christina M.; Landman, Willem A.; Adeola, Abiodun M.

    2016-04-01

    In this study, average monthly and annual rainfall totals recorded for the period 1970 to 2010 from a network of 13 stations across the Lake Kariba catchment area of the Zambezi river basin were analyzed in order to characterize the spatial-temporal variability of rainfall across the catchment area. In the analysis, the data were subjected to intervention and homogeneity analysis using the Cumulative Summation (CUSUM) technique and step change analysis using rank-sum test. Furthermore, rainfall variability was characterized by trend analysis using the non-parametric Mann-Kendall statistic. Additionally, the rainfall series were decomposed and the spectral characteristics derived using Cross Wavelet Transform (CWT) and Wavelet Coherence (WC) analysis. The advantage of using the wavelet-based parameters is that they vary in time and can therefore be used to quantitatively detect time-scale-dependent correlations and phase shifts between rainfall time series at various localized time-frequency scales. The annual and seasonal rainfall series were homogeneous and demonstrated no apparent significant shifts. According to the inhomogeneity classification, the rainfall series recorded across the Lake Kariba catchment area belonged to category A (useful) and B (doubtful), i.e., there were zero to one and two absolute tests rejecting the null hypothesis (at 5 % significance level), respectively. Lastly, the long-term variability of the rainfall series across the Lake Kariba catchment area exhibited non-significant positive and negative trends with coherent oscillatory modes that are constantly locked in phase in the Morlet wavelet space.

  11. 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

  12. Spatial moments of catchment rainfall: rainfall spatial organisation, basin morphology, and flood response

    NASA Astrophysics Data System (ADS)

    Zoccatelli, D.; Borga, M.; Viglione, A.; Chirico, G. B.; Blöschl, G.

    2011-06-01

    This paper provides a general analytical framework for assessing the dependence existing between spatial rainfall organisation, basin morphology and runoff response. The analytical framework builds upon a set of spatial rainfall statistics (termed "spatial moments of catchment rainfall") which describe the spatial rainfall organisation in terms of concentration and dispersion statistics as a function of the distance measured along the flow routing coordinate. The introduction of these statistics permits derivation of a simple relationship for the quantification of storm velocity at the catchment scale. The paper illustrates the development of the analytical framework and explains the conceptual meaning of the statistics by means of application to five extreme flash floods occurred in various European regions in the period 2002-2007. High resolution radar rainfall fields and a distributed hydrologic model are employed to examine how effective are these statistics in describing the degree of spatial rainfall organisation which is important for runoff modelling. This is obtained by quantifying the effects of neglecting the spatial rainfall variability on flood modelling, with a focus on runoff timing. The size of the study catchments ranges between 36 to 982 km2. The analysis reported here shows that the spatial moments of catchment rainfall can be effectively employed to isolate and describe the features of rainfall spatial organization which have significant impact on runoff simulation. These statistics provide essential information on what space-time scales rainfall has to be monitored, given certain catchment and flood characteristics, and what are the effects of space-time aggregation on flood response modeling.

  13. 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

  14. 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.

  15. Assessment of Wetland Hydrological Dynamics in a Modified Catchment Basin: Case of Lake Buninjon, Victoria, Australia.

    PubMed

    Yihdego, Yohannes; Webb, John A

    2017-02-01

      The common method to estimate lake levels is the water balance equation, where water input and output result in lake storage and water level changes. However, all water balance components cannot always be quickly assessed, such as due to significant modification of the catchment area. A method that assesses general changes in lake level can be a useful tool in examining why lakes have different lake level variation patterns. Assessment of wetlands using the dynamics of the historical hydrological and hydrogeological data set can provide important insights into variations in wetland levels in different parts of the world. A case study from a saline landscape, Lake Buninjon, Australia, is presented. The aim of the present study was to determine how climate, river regime, and lake hydrological properties independently influence lake water levels and salinity, leaving the discrepancy, for the effect of the non-climatic/catchment modification in the past and the model shows that surface inflow is most sensitive variable. The method, together with the analysis and interpretation, might be of interest to wider community to assess its response to natural/anthropogenic stress and decision choices for its ecological, social, scientific value, and mitigation measures to safe guard the wetland biodiversity in a catchment basin.

  16. 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

  17. Implementing Integrated Catchment Management in the upper Limpopo River basin: A situational assessment

    NASA Astrophysics Data System (ADS)

    Mwenge Kahinda, J.; Meissner, R.; Engelbrecht, F. A.

    2016-06-01

    A three-phase study was initiated as a way to promote Integrated Catchment Management approaches in the Limpopo River basin. This paper presents the situational assessment, which should enable De Beers to understand how their Venetia Mine operations are located within a broader and highly dynamic socio-economic and ecohydrological landscape as it pertains to water risks. The second phase, Risk assessment, aims to develop conservation interventions in the identified areas; the third phase will develop mechanisms for implementing water stewardship schemes to mitigate the shared water risks. Analysis of the social-ecological system (hydrological, climatic, ecological, socio-economic and governance systems) of the Limpopo River basin indicates that the institutional arrangement of the Limpopo River basin is neither simple nor effective. The basin is rapidly approaching closure in the sense that almost all of the available supplies of water have already been allocated to existing water users. If the proposed ecological flow requirements were to be met for all of the tributaries, the basin would be 'closed'. On-going and projected land use changes and water resources developments in the upper reaches of the basin, coupled with projected rainfall reductions and temperature increases, and allocation of the flows for the ecological reserve, are likely to further reduce downstream river flows. The coupled increase in temperature and decrease in rainfall is of great concern for everyone in the basin, especially the poorer communities, who rely on rain-fed agriculture for their livelihoods. Increased temperatures also lead to increased evaporation from reservoirs and therefore result in a decrease in water availability. This will lead to increased abstraction of groundwater, especially from alluvial aquifers, and consequently an increase in river transmission losses and a decrease in river flows.

  18. Effects of land cover change on evapotranspiration and streamflow of small catchments in the Upper Xingu River Basin, Central Brazi

    NASA Astrophysics Data System (ADS)

    Costa, M. H.; Dias, L. C. P.; Macedo, M.; Coe, M. T.; Neill, C.

    2014-12-01

    This study assess the influence of land cover changes on evapotranspiration and streamflow in small catchments in the Upper Xingu River Basin (Mato Grosso state, Brazil). Streamflow was measured in catchments with uniform land use for September 1, 2008 to August 31, 2010. We used models to simulate evapotranspiration and streamflow for the four most common land cover types found in the Upper Xingu: tropical forest, cerrado (savanna), pasture, and soybean croplands. We used INLAND to perform single point simulations considering tropical rainforest, cerrado and pasturelands, and AgroIBIS for croplands. Converting natural vegetation to agriculture substantially modifies evapotranspiration and streamflow in small catchments. Measured mean streamflow in soy catchments was about three times greater than that of forest catchments, while the mean annual amplitude of flow in soy catchments was more than twice that of forest catchments. Simulated mean annual evapotranspiration was 39% lower in agricultural ecosystems (pasture and soybean cropland) than in natural ecosystems (tropical rainforest and cerrado). Observed and simulated mean annual streamflows in agricultural ecosystems were more than 100% higher than in natural ecosystems. The accuracy of the simulations is improved by using field-measured soil hydraulic properties. The inclusion of local measurements of key soil parameters is likely to improve hydrological simulations in other tropical regions.

  19. Effects of land cover change on evapotranspiration and streamflow of small catchments in the Upper Xingu River Basin, Central Brazi

    NASA Astrophysics Data System (ADS)

    Costa, M. H.; Dias, L. C. P.; Macedo, M.; Coe, M. T.; Neill, C.

    2015-12-01

    This study assess the influence of land cover changes on evapotranspiration and streamflow in small catchments in the Upper Xingu River Basin (Mato Grosso state, Brazil). Streamflow was measured in catchments with uniform land use for September 1, 2008 to August 31, 2010. We used models to simulate evapotranspiration and streamflow for the four most common land cover types found in the Upper Xingu: tropical forest, cerrado (savanna), pasture, and soybean croplands. We used INLAND to perform single point simulations considering tropical rainforest, cerrado and pasturelands, and AgroIBIS for croplands. Converting natural vegetation to agriculture substantially modifies evapotranspiration and streamflow in small catchments. Measured mean streamflow in soy catchments was about three times greater than that of forest catchments, while the mean annual amplitude of flow in soy catchments was more than twice that of forest catchments. Simulated mean annual evapotranspiration was 39% lower in agricultural ecosystems (pasture and soybean cropland) than in natural ecosystems (tropical rainforest and cerrado). Observed and simulated mean annual streamflows in agricultural ecosystems were more than 100% higher than in natural ecosystems. The accuracy of the simulations is improved by using field-measured soil hydraulic properties. The inclusion of local measurements of key soil parameters is likely to improve hydrological simulations in other tropical regions.

  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. San Mateo Creek Basin Preliminary Assessment

    EPA Pesticide Factsheets

    The objective of this Preliminary Assessment is to evaluate the site using the Hazard Ranking System and the Superfund Chemical Data Matrix to determine if a threat to human health and the environment exists such that further action is warranted.

  2. 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 1.30Ñ 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

  3. Applicability of LOICZ catchment coast continuum in a major Caribbean basin: The Magdalena River, Colombia

    NASA Astrophysics Data System (ADS)

    Restrepo, Juan D.

    2008-04-01

    Within the Land Ocean Interactions in the Coastal Zone (LOICZ)-Basins approach, the Magdalena River Project (MRP) is an interdisciplinary research, which aims to improve the scientific understanding of the linkages between the Magdalena drainage basin and its associated coastal environments. The MRP is an outgrowth of the initial regional planning that resulted from the LOICZ South American Basins (SamBas) and Caribbean Basins (CariBas) studies on land use and hydrological changes during approximately the past century in tropical and temperate benchmark river basins. The results of the MRP presented in this article show that the extent of land-cover change and erosion within the catchment has increased over the last 10-20 yr. The overall increasing trends in sediment load on a regional scale may be attributed to a range of anthropogenic influences including: a 40% decrease in forests over a 20-yr period; a 65% increase in agricultural and pasture; poor practices of land use; mining; and increasing rates of urbanization. These increasing trends in sediment load coincide with the overall decline of live coral cover in a 145-km 2 coral reef complex in the Caribbean Sea. In addition, the impacts of heavy sediment loads and freshwater discharges have greatly contributed not only to the total disappearance of coral formations but also to a considerable reduction in abundance of seagrass beds in Cartagena Bay and neighbouring areas. The synthesis and analysis presented in this article are just first steps toward understanding the natural and human-induced factors that have produced the observed patterns of water discharge and sediment load of the Magdalena River into the Caribbean Sea, and to relating these processes to the impact on coastal ecosystems.

  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

    2002-10-07

    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.

  5. Variability of streamflow under climate change: A study for 26 Brazilian large basins and sub-catchments.

    NASA Astrophysics Data System (ADS)

    Isidoro, Jorge; Tiezzi, Rafael

    2016-04-01

    Human activity is entirely dependent on water resources, thus highly vulnerable to the effects of rainfall variability. This work aims to analyse the impact of rainfall variability on streamflow for 26 Brazilian large basins and sub-catchments. Records form 83-years of observations (1931-2013) were compared with the results of simulations for the 2011-2100 (90-year) period. Two rainfall-runoff hydrological models were used for the numerical simulations: Soil Moisture Accounting Procedure-SMAP (process-based) and Stochastic Linear Model-MEL (stochastic). Very significant impacts were found, namely the increase in streamflow in the Southern basins that may reach almost 100%, while in the Northern and Northeastern basins, streamflow may decrease about 90%. These major changes can aggravate the history of flooding in the Southern basins and of droughts in several regions of the North and Northeast basins.

  6. Mean Transit Times in Seven Upland Catchments, Otway Basin, Southeast Australia

    NASA Astrophysics Data System (ADS)

    Howcroft, William; Cartwright, Ian; Morgenstern, Uwe

    2016-04-01

    The timescales over which precipitation is transmitted into upland streams (the mean transit times, MTTs) are poorly understood, as are the physical processes and controls that govern the variation in mean transit times. In this study, we use tritium (3H), major ion geochemistry and discharge data to investigate the MTTs in upland streams of the Otway Basin of southeast Australia. Samples were collected under varying discharge conditions from seven catchments of varying size whose land use varies from relatively pristine eucalyptus forest to a mixture of pasture, grazing, and production forestry. This allows the controls on MTTs to be assessed. Tritium activities within the streams varied from 0.20 to 2.35 TU, which are below that of local rainfall (~2.7 TU). The highest tritium activities were generally reported in samples collected during periods of high winter discharge, while the lowest tritium activities were reported in samples collected during low, summer discharge. However, at several of the streams, there appears to be a discharge threshold above which tritium activities do not increase appreciably with increased discharge. In general, streams with larger catchment areas and relatively simple geology have less variable but higher tritium activities. In contrast, the lowest and most variable tritium activities were reported in streams having small catchment areas and a greater complexity in geology. MTTs calculated using an exponential-piston flow model ranged between 8 and 180 years; MTTs calculated using other flow models were generally similar, except where the tritium activities were less than around 1 TU. Major ion concentrations generally increased with a corresponding increase in MTT. However, in those streams having more variable MTTs, the opposite often held true, which most likely reflects the variable contribution to flow by water from different geologic units under differing flow conditions. By contrast, land use does not appear to impart a

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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. 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.

  12. Application of Basin Morphometry Laws in catchments of the south-western quadrangle of south-eastern Nigeria

    NASA Astrophysics Data System (ADS)

    Aisuebeogun, A. O.; Ezekwe, I. C.

    2013-09-01

    The relationship between process and form has been at the core of research in fluvial geomorphology. Form-process relationships of a natural river basin are strongly influenced by its hydrologic and sedimentologic processes as basin morphometric properties of length, shape, and relief, change in response to various hydrologic stimuli from the environment, but usually in line with well established laws. In the four river basins (Orashi, Otamiri, Sombreiro, New Calabar) examined in this study, however, empirical evidence does not conform neatly with theoretical postulates. Remarkable variations are noted in the morphometric properties of the catchments, when compared with established morphometric laws. The most varied in conformity are the Orashi and New Calabar basins, although the Sombreiro and Otamiri catchments also show some level of variation. Prime explanation for the morphometric and topographic non-conformity is caused by the nature of surficial material and the profoundly shallow relief of much of the study area, especially the alluvial flood and deltaic plains to the south and south-west of the study area.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

    Hüffmeyer, 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

  15. 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, François; Foucher, Anthony; Salvador-Blanes, Sébastien; 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 km², 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 (2σ, 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, 2σ, n=20) plotted between the soil and sediment core (0.712255 to 0.716415 ± 0.000017, 2σ, 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

  16. Validation of soil hydraulic pedotransfer functions at the local and catchment scale for an Indonesian basin

    NASA Astrophysics Data System (ADS)

    Booij, Martijn J.; Oldhoff, Ruben J. J.; Rustanto, Andry

    2016-04-01

    In order to accurately model the hydrological processes in a catchment, information on the soil hydraulic properties is of great importance. These data can be obtained by conducting field work, which is costly and time consuming, or by using pedotransfer functions (PTFs). A PTF is an empirical relationship between easily obtainable soil characteristics and a soil hydraulic parameter. In this study, PTFs for the saturated hydraulic conductivity (Ks) and the available water content (AWC) are investigated. PTFs are area-specific, since for instance tropical soils often have a different composition and hydraulic behaviour compared to temperate soils. Application of temperate soil PTFs on tropical soils might result in poor performance, which is a problem as few tropical soil PTFs are available. The objective of this study is to determine whether Ks and AWC can be accurately approximated using PTFs, by analysing their performance at both the local scale and the catchment scale. Four published PTFs for Ks and AWC are validated on a data set of 91 soil samples collected in the Upper Bengawan Solo catchment on Java, Indonesia. The AWC is predicted very poorly, with Nash-Sutcliffe Efficiency (NSE) values below zero for all selected PTFs. For Ks PTFs better results were found. The Wösten and Rosetta-3 PTFs predict the Ks moderately accurate, with NSE values of 0.28 and 0.39, respectively. New PTFs for both AWC and Ks were developed using multiple linear regression and NSE values of 0.37 (AWC) and 0.55 (Ks) were obtained. Although these values are not very high, they are significantly higher than for the published PTFs. The hydrological SWAT model was set up for the Keduang, a sub-catchment of the Upper Bengawan Solo River, to simulate monthly catchment streamflow. Eleven cases were defined to validate the PTFs at the catchment scale. For the Ks-PTF cases NSE values of around 0.84 were obtained for the validation period. The use of AWC PTFs resulted in slightly lower NSE

  17. 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 (δ18O) and hydrogen (δ2H), and radioactive isotopes of carbon (δ14C), hydrogen (tritium δ3H) and helium (δ3He)) to assess groundwater quality and origin. Preliminary results show that the signature of melt water from permafrost thawing is observed in the

  18. 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.

  19. River water quality of the River Cherwell: an agricultural clay-dominated catchment in the upper Thames Basin, southeastern England.

    PubMed

    Neal, Colin; Neal, Margaret; Hill, Linda; Wickham, Heather

    2006-05-01

    The water quality of the River Cherwell and a tributary of it, the Ray, are described in terms of point and diffuse sources of pollution, for this rural area of the upper Thames Basin. Point sources of pollution dominate at the critical ecological low flow periods of high biological activity. Although the surface geology is predominantly clay, base flow is partly supplied from springs in underlying carbonate-bearing strata, which influences the water quality particularly with regards to calcium and alkalinity. The hydrogeochemistry of the river is outlined and the overall importance of urban point sources even in what would normally be considered to be rural catchments is stressed in relation to the European Unions Water Framework Directive. Issues of phosphorus stripping at sewage treatment works are also considered: such stripping on the Cherwell has reduced phosphorus concentrations by about a factor of two, but this is insufficient for the needs of the Water Framework Directive.

  20. 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 (δ(18)O, δ(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.

  1. 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

  2. Simulating wind-affected snow accumulations at catchment to basin scales

    NASA Astrophysics Data System (ADS)

    Winstral, Adam; Marks, Danny; Gurney, Robert

    2013-05-01

    In non-forested mountain regions, wind plays a dominant role in determining snow accumulation and melt patterns. A new, computationally efficient algorithm for distributing the complex and heterogeneous effects of wind on snow distributions was developed. The distribution algorithm uses terrain structure, vegetation, and wind data to adjust commonly available precipitation data to simulate wind-affected accumulations. This research describes model development and application in three research catchments in the Reynolds Creek Experimental Watershed in southwest Idaho, USA. All three catchments feature highly variable snow distributions driven by wind. The algorithm was used to derive model forcings for Isnobal, a mass and energy balance distributed snow model. Development and initial testing took place in the Reynolds Mountain East catchment (0.36 km2) where R2 values for the wind-affected snow distributions ranged from 0.50 to 0.67 for four observation periods spanning two years. At the Upper Sheep Creek catchment (0.26 km2) R2 values for the wind-affected model were 0.66 and 0.70. These R2 values matched or exceeded previously published cross-validation results from regression-based statistical analyses of snow distributions in similar environments. In both catchments the wind-affected model accurately located large drift zones, snow-scoured slopes, and produced melt patterns consistent with observed streamflow. Models that did not account for wind effects produced relatively homogenous SWE distributions, R2 values approaching 0.0, and melt patterns inconsistent with observed streamflow. The Dobson Creek (14.0 km2) application incorporated elevation effects into the distribution routine and was conducted over a two-dimensional grid of 6.67 × 105 pixels. Comparisons with satellite-derived snow-covered-area again demonstrated that the model did an excellent job locating regions with wind-affected snow accumulations. This final application demonstrated that the

  3. Evaluation and inter-comparison of Global Climate Models’ performance over Katonga and Ruizi catchments in Lake Victoria basin

    NASA Astrophysics Data System (ADS)

    Nyeko-Ogiramoi, P.; Ngirane-Katashaya, G.; Willems, P.; Ntegeka, V.

    Regional impact assessments of climate change on hydrological extremes require robust examinations of climate model simulations. The climate models may satisfy mean statistics but fail to reproduce extreme quantiles which are crucial for applications of climate change impact analysis on water resources. Through statistical analysis, this paper evaluates and inter-compares the performance of Global Climate Model (GCM) simulations for their ability to predict changes in hydrological extremes for given locations or catchments in the Nile basin. Two catchments were considered: Katonga and Ruizi catchments in the Lake Victoria basin. Models that differ significantly from the observed extremes were considered unreliable for impact assessments on hydrological extremes. A graphical approach (rainfall quantile/frequency analysis), which allows for easy spotting of discordant models, in combination with several statistics, was used to evaluate 18 GCM control simulations against observed rainfall data. Standard deviation, coefficient of variation and root mean squared error (about the mean) of the observed rainfall, were used to derive error margins against which GCM simulations were evaluated. Model results outside the error margins were considered inconsistent with the observed rainfall. Model inter-comparison was also carried out for the rainfall change projections till the 2050s and 2090s through analysis of perturbations and percentage changes based on A1B, A2, and B1 SRES scenarios. It is noted that the GCM outputs are more consistent in reproducing rainfall signatures at annual aggregation level than at monthly aggregation levels with tendency of overestimation of the rainfall depths but with significant variation among different GCM simulations. The GCMs perform better in reproducing rainfall frequency with higher return periods compared with lower return periods. Most of the GCMs perform better for the wet months than the drier months. The GCMs CGCM3.2a, CM3.O, CM4

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

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

    PubMed

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

    2015-01-02

    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.

  6. 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

  7. 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; 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).

  8. Environmental flows allocation in river basins: Exploring allocation challenges and options in the Great Ruaha River catchment in Tanzania

    NASA Astrophysics Data System (ADS)

    Kashaigili, Japhet J.; Kadigi, Reuben M. J.; Lankford, Bruce A.; Mahoo, Henry F.; Mashauri, Damus A.

    Provision for environmental flows is currently becoming a central issue in the debate of integrated water resources management in river basins. However, the theories, concepts and practical applications are still new in most developing countries with challenging situations arising in complex basins with multiple water uses and users and increasing water demands and conflicts exemplified by the Great Ruaha River catchment in Tanzania. The research has shown that a flow of 0.5-1 m 3/s for Great Ruaha River through the Ruaha National Park is required to sustain the environment in the park during the dry season. But a question is how can this be achieved? This paper reviews the challenges and suggests some options for achieving environmental water allocation in river basins. The following challenges are identified: (a) the concept of environmental flows is still new and not well known, (b) there is limited data and understanding of the hydrologic and ecological linkages, (c) there is insufficient specialist knowledge and legislative support, (d) there are no storage reservoirs for controlled environmental water releases, and (e) there are contradicting policies and institutions on environmental issues. Notwithstanding these challenges, this paper identifies the options towards meeting environmental water allocation and management: (a) conducting purposive training and awareness creation to communities, politicians, government officials and decision makers on environmental flows, (b) capacity building in environmental flows and setting-up multidisciplinary environmental flows team with stakeholders involvement, (c) facilitating the development of effective local institutions supported by legislation, (d) water harvesting and storage and proportional flow structures design to allow water for the environment, and (e) harmonizing policies and reform in water utilization and water rights to accommodate and ensure water for the environment.

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

    USGS Publications Warehouse

    Coleman, James L.; 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.

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

  12. Estimation of the relative severity of floods in small ungauged catchments for preliminary observations on flash flood preparedness: a case study in Korea.

    PubMed

    Kim, Eung Seok; Choi, Hyun Il

    2012-04-01

    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.

  13. 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

  14. 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; 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).

  15. 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; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

  19. 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; 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).

  20. 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; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

  2. 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; 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).

  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; 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: Estimated Mean Annual Natural Groundwater Recharge, 2002

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

  5. 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; 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).

  6. 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; 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).

  7. Catchment-flowline network and selected model inputs for an enhanced and updated spatially referenced statistical assessment of dissolved-solids load sources and transport in streams of the Upper Colorado River Basin

    USGS Publications Warehouse

    Buto, Susan G.; Spangler, Lawrence E.; Flint, Alan L.; Flint, Lorraine E.

    2017-01-01

    This USGS data release consists of the synthetic stream network and associated catchments used to develop spatially referenced regressions on watershed attributes (SPARROW) model of dissolved-solids sources and transport in the Upper Colorado River Basin as well as geology and selected Basin Characterization Model (BCM) data used as input to the model.

  8. 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

  9. 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.

  10. 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

  11. How accurately are climatological characteristics and surface water and energy balances represented for the Colombian Caribbean Catchment Basin?

    NASA Astrophysics Data System (ADS)

    Hoyos, Isabel; Baquero-Bernal, Astrid; Hagemann, Stefan

    2013-09-01

    In Colombia, the access to climate related observational data is restricted and their quantity is limited. But information about the current climate is fundamental for studies on present and future climate changes and their impacts. In this respect, this information is especially important over the Colombian Caribbean Catchment Basin (CCCB) that comprises over 80 % of the population of Colombia and produces about 85 % of its GDP. Consequently, an ensemble of several datasets has been evaluated and compared with respect to their capability to represent the climate over the CCCB. The comparison includes observations, reconstructed data (CPC, Delaware), reanalyses (ERA-40, NCEP/NCAR), and simulated data produced with the regional climate model REMO. The capabilities to represent the average annual state, the seasonal cycle, and the interannual variability are investigated. The analyses focus on surface air temperature and precipitation as well as on surface water and energy balances. On one hand the CCCB characteristics poses some difficulties to the datasets as the CCCB includes a mountainous region with three mountain ranges, where the dynamical core of models and model parameterizations can fail. On the other hand, it has the most dense network of stations, with the longest records, in the country. The results can be summarised as follows: all of the datasets demonstrate a cold bias in the average temperature of CCCB. However, the variability of the average temperature of CCCB is most poorly represented by the NCEP/NCAR dataset. The average precipitation in CCCB is overestimated by all datasets. For the ERA-40, NCEP/NCAR, and REMO datasets, the amplitude of the annual cycle is extremely high. The variability of the average precipitation in CCCB is better represented by the reconstructed data of CPC and Delaware, as well as by NCEP/NCAR. Regarding the capability to represent the spatial behaviour of CCCB, temperature is better represented by Delaware and REMO, while

  12. 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

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

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

    USGS Publications Warehouse

    Wieczorek, Michael; 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).

  15. 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.

  16. Two Preliminary SRTM DEMs Within the Amazon Basin

    NASA Astrophysics Data System (ADS)

    Alsdorf, D.; Hess, L.; Melack, J.; Dunne, T.; Mertes, L.; Ballantine, A.; Biggs, T.; Holmes, K.; Sheng, Y.; Hendricks, G.

    2002-12-01

    Digital topography provides important measures, such as hillslope lengths and flow path networks, for understanding hydrologic and geomorphic processes (e.g., runoff response to land use change and floodplain inundation volume). Two preliminary Shuttle Radar Topography Mission digital elevation models of Manaus (1S to 5S and 59W to 63W) and Rondonia (9S to 12S and 61W to 64W) were received from NASA JPL in August 2002. The "PI Processor" produced these initial DEM segments and we are using them to assess the initial accuracy of the interferometrically derived heights and for hydrologic research. The preliminary SRTM derived absolute elevations across the Amazon floodplain in the Cabaliana region generally range from 5 to 15 m with reported errors of 1 to 3 m. This region also includes some preliminary elevations that are erroneously negative. However, topographic contours on 1:100,000 scale quadrangles of 1978 to 1980 vintage indicate elevations of 20 to 30 m. Because double-bounce travel paths are possible over the sparsely vegetated and very-flat 2400 sq-km water surface of the Balbina reservoir near Manaus, it serves to identify the relative accuracy of the SRTM heights. Here, cell-to-cell height changes are generally 0 to 1 m and changes across a ~100 km transect rarely exceed 3 m. Reported errors throughout the transect range from 1 to 2 m with some errors up to 5 m. Deforestation in Rondonia is remarkably clear in the C-band DEM where elevations are recorded from the canopy rather than bare earth. Here, elevation changes are ~30 m (with reported 1 to 2 m errors) across clear-cut areas. Field derived canopy heights are in agreement with this change. Presently, we are deriving stream networks in the Amazon floodplain for comparison with our previous network extraction from JERS-1 SAR mosaics and for hydrologic modeling.

  17. 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

  18. Hydro-meteorological functioning of the Eastern Andean Tropical Montane Cloud Forests: Insight from a paired catchment study in the Orinoco river basin highlands

    NASA Astrophysics Data System (ADS)

    Ramirez, Beatriz; Teuling, Adriaan J.; Ganzeveld, Laurens; Leemans, Rik

    2016-04-01

    Tropical forests regulate large scale precipitation patterns and catchment-scale streamflow, while tropical mountains influence runoff by orographic effects and snowmelt. Along tropical elevation gradients, these climate/ecosystem/hydrological interactions are specific and heterogeneous. These interactions are poorly understood and represented in hydro-meteorological monitoring networks and regional or global earth system models. A typical case are the South American Tropical Montane Cloud Forests (TMCF), whose water balance is strongly driven by fog persistence. This also depends on local and up wind temperature and moisture, and changes in this balance alter the impacts of changes in land use and climate on hydrology. These TMCFs were until 2010 only investigated up to 350km from the coast. Continental TMCFs are largely ignored. This gap is covered by our study area, which is part of the Orinoco river basin highlands and located on the northern Eastern Andes at an altitudinal range of 1550 to 2300m a.s.l. The upwind part of our study area is dominated by lowland savannahs that are flooded seasonally. Because meteorological stations are absent in our study area, we first describe the spatial and seasonal meteorological variability and analyse the corresponding catchment hydrology. Our hydro-meteorological data set is collected at three gauged neighbouring catchments with contrasting TMCF/grassland cover from June 2013 to May 2014 and includes hourly solar radiation, temperature, relative humidity, wind speed, precipitation, soil moisture and runoff measurements. We compare our results with recent TCMF studies in the eastern Andean highlands in the Amazon basin. The studied elevational range always shows wetter conditions at higher elevations. This indicates a positive relation between elevation and fog or rainfall persistence. Lower elevations are more seasonally variable. Soil moisture data indicate that TMCFs do not use persistently more water than grasslands

  19. 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

  20. 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; 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.

  1. 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.

  2. 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.

  3. 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; 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

  4. 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.

  5. 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.

  6. Scale-dependence effects of landscape on seasonal water quality in Xitiaoxi catchment of Taihu Basin, China.

    PubMed

    Lv, Huihua; Xu, Youpeng; Han, Longfei; Zhou, Feng

    2015-01-01

    Further understanding the mechanisms of landscape-water interactions is of great importance to water quality management in the Xitiaoxi catchment. Pearson's correlation analysis, stepwise multiple regression and redundancy analysis were adopted in this study to investigate the relation between water quality and landscape at the sub-catchment and 200 m riparian zone scales during dry and wet seasons. Landscape was characterized by natural environmental factors, land use patterns and four selected landscape configuration metrics. The obtained results indicated that land use categories of urban and forest were dominant landscape attributes, which influenced water quality. Natural environment and landscape configuration were overwhelmed due to land management activities and hydrologic conditions. In general, the landscape of the 200 m riparian zone appeared to have slightly greater influence on water than did the sub-catchment, and water quality was slightly better explained by all landscape attributes in the wet season than in the dry season. The results suggested that management efforts aimed at maintaining and restoring river water quality should currently focus on the protection of riparian zones and the development of an updated long-term continuous data set and higher resolution digital maps to discuss the minimum width of the riparian zone necessary to protect water quality.

  7. 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

  8. 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

  9. Evaluation of precipitation input for SWAT modeling in Alpine catchment: A case study in the Adige river basin (Italy).

    PubMed

    Tuo, Ye; Duan, Zheng; Disse, Markus; Chiogna, Gabriele

    2016-12-15

    Precipitation is often the most important input data in hydrological models when simulating streamflow. The Soil and Water Assessment Tool (SWAT), a widely used hydrological model, only makes use of data from one precipitation gauge station that is nearest to the centroid of each subbasin, which is eventually corrected using the elevation band method. This leads in general to inaccurate representation of subbasin precipitation input data, particularly in catchments with complex topography. To investigate the impact of different precipitation inputs on the SWAT model simulations in Alpine catchments, 13years (1998-2010) of daily precipitation data from four datasets including OP (Observed precipitation), IDW (Inverse Distance Weighting data), CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) and TRMM (Tropical Rainfall Measuring Mission) has been considered. Both model performances (comparing simulated and measured streamflow data at the catchment outlet) as well as parameter and prediction uncertainties have been quantified. For all three subbasins, the use of elevation bands is fundamental to match the water budget. Streamflow predictions obtained using IDW inputs are better than those obtained using the other datasets in terms of both model performance and prediction uncertainty. Models using the CHIRPS product as input provide satisfactory streamflow estimation, suggesting that this satellite product can be applied to this data-scarce Alpine region. Comparing the performance of SWAT models using different precipitation datasets is therefore important in data-scarce regions. This study has shown that, precipitation is the main source of uncertainty, and different precipitation datasets in SWAT models lead to different best estimate ranges for the calibrated parameters. This has important implications for the interpretation of the simulated hydrological processes.

  10. Study of water quality distribution in Lake Biwa in consideration of runoff pollutant loads from its catchment basin.

    PubMed

    Ichiki, A; Sasaki, A; Sakata, N; Nakakura, K; Yamate, H

    2006-01-01

    Many strategies for water quality conservation in Lake Biwa are being carried out mainly by reducing runoff pollutant loads into the lake. But influence of the runoff load reduction on the water quality in Lake Biwa has not been clarified enough so far. This study is aimed at discussing methodology to estimate water quality distribution in Lake Biwa using runoff pollutant loads from its basin. The runoff loads from the basin are calculated by Macro Model with GIS database of the Lake Biwa basin, and the water quality distribution in the lake is estimated by the spline technique with the calculated runoff loads. As a result, it has been proved that the methodology has enough reproducibility to estimate the water quality distribution in Lake Biwa and is available to examine the water quality in the lake.

  11. 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

  12. 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

  13. 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

    , preliminary results highlighted that about 50-55% of the sediment located in the deposition area originated from the main grassed waterway of the catchment.

  14. Vulnerability of European freshwater catchments to climate change.

    PubMed

    Markovic, Danijela; Carrizo, Savrina F; Kärcher, Oskar; Walz, Ariane; David, Jonathan N W

    2017-02-10

    Climate change is expected to exacerbate the current threats to freshwater ecosystems, yet multifaceted studies on the potential impacts of climate change on freshwater biodiversity at scales that inform management planning are lacking. The aim of this study was to fill this void through the development of a novel framework for assessing climate change vulnerability tailored to freshwater ecosystems. The three dimensions of climate change vulnerability are as follows: (i) exposure to climate change, (ii) sensitivity to altered environmental conditions and (iii) resilience potential. Our vulnerability framework includes 1685 freshwater species of plants, fishes, molluscs, odonates, amphibians, crayfish and turtles alongside key features within and between catchments, such as topography and connectivity. Several methodologies were used to combine these dimensions across a variety of future climate change models and scenarios. The resulting indices were overlaid to assess the vulnerability of European freshwater ecosystems at the catchment scale (18 783 catchments). The Balkan Lakes Ohrid and Prespa and Mediterranean islands emerge as most vulnerable to climate change. For the 2030s, we showed a consensus among the applied methods whereby up to 573 lake and river catchments are highly vulnerable to climate change. The anthropogenic disruption of hydrological habitat connectivity by dams is the major factor reducing climate change resilience. A gap analysis demonstrated that the current European protected area network covers <25% of the most vulnerable catchments. Practical steps need to be taken to ensure the persistence of freshwater biodiversity under climate change. Priority should be placed on enhancing stakeholder cooperation at the major basin scale towards preventing further degradation of freshwater ecosystems and maintaining connectivity among catchments. The catchments identified as most vulnerable to climate change provide preliminary targets for

  15. Suspended sediment yield and metal contamination in a river catchment affected by El Niño events and gold mining activities: the Puyango river basin, southern Ecuador

    NASA Astrophysics Data System (ADS)

    Tarras-Wahlberg, N. H.; Lane, S. N.

    2003-10-01

    The suspended sediment yield and the transfer of polluted sediment are investigated for the Puyango river basin in southern Ecuador. This river system receives metal (Cd, Cu, Hg, Pb and Zn) and cyanide pollution generated by mining, and is associated with large-scale hydrological variability, which is partly governed by El Niño events. Field sampling and statistical modelling methods are used to quantify the amount of mine tailings that is discharged into the basin. Annual suspended sediment yields are estimated using a novel combination of the suspended sediment rating method and Monte Carlo simulations, which allow for propagation of the uncertainties of the calculations that lead to final load estimates. Geochemical analysis of suspended and river bed sediment is used to assess the dispersion and long-term fate of contaminated sediment within the river catchment. Knowledge of the inter- and intra-annual variation in suspended sediment yield is shown to be crucial for judging the importance of mining discharges, and the extent to which the resultant pollution is diluted by river flows. In wet years, polluted sediments represent only a very small proportion of the yield estimates, but in dry years the proportion can be significant. Evidence shows that metal contaminated sediments are stored in the Puyango river bed during low flows. Large flood events flush this sediment periodically, both on an annual cycle associated with the rainy season, and also related to El Niño events. Therefore, environmental impacts of mining-related discharges are more likely to be severe during dry years compared with wet years, and in the dry season rather than the wet season. The hydrological consequences of El Niño events are shown to depend upon the extent to which these events penetrate inland. It is, thus, shown that the general conclusion that El Niño events can significantly affect suspended sediment yields needs evaluation with respect to the particular way in which those

  16. Preliminary assessment of channel stability and bed-material transport in the Coquille River basin, southwestern Oregon

    USGS Publications Warehouse

    Jones, Krista L.; O'Connor, Jim E.; Keith, Mackenzie K.; Mangano, Joseph F.; Wallick, J. Rose

    2012-01-01

    This report summarizes a preliminary study of bed-material transport, vertical and lateral channel changes, and existing datasets for the Coquille River basin, which encompasses 2,745 km2 (square kilometers) of the southwestern Oregon coast. This study, conducted to inform permitting decisions regarding instream gravel mining, revealed that:

  17. 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; 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).

  18. 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; 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).

  19. Potential for chemical transport beneath a storm-runoff recharge (retention) basin for an industrial catchment in Fresno, California

    USGS Publications Warehouse

    Schroeder, R.A.

    1995-01-01

    A wide variety of chemicals from urban runoff were found at elevated concentrations in sediment that accumulated in a storm-runoff recharge basin in an industrial part of the city of Fresno. The chemicals include as many as 20 inorganic elements and about the same number of organic compounds, primarily organochlorine pesticides and polycyclic aromatic hydrocarbons. Most of these contaminants were found to be sorbed to the upper 4 centimeters of sediment, which also is the maximum depth to which atmospheric lead-210 penetrated. None of the contaminants were detected above background concentrations in the sediment at depths greater than 16 centimeters. In shallow sediment, zinc is the inorganic element that showed the greatest enrichment; its concentration was 38 times higher in surface sediment (0-1 centimeter) than in deeper strata (below 16 centi- meters). Organic carbon enrichment in the surface sediment was nearly 1,000 times. Although batch- elutriation experiments demonstrated the potential for leaching of contaminants attached to sediments, a sharp decrease in concentrations with increasing sediment depth, and the extremely low level of contaminants in two monitor wells adjacent to the basin, confirmed the absence of contaminant transport to the water table. Continued long-term protection for ground water is afforded by an approximately 8-meter-thick unsaturated zone beneath the basin. On the basis of its hundredfold-higher concentration in the recharge pond then in ground water, zinc is indicated as the most sensitive surrogate for monitoring possible ground-water degradation by inorganic cations.

  20. 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.

  1. Isotopic Insights into Catchment Hydrology: Use of Tritium and Oxygen-18 to Interpret Age and Flow Paths of Waters in the Langtang River Basin, Nepal

    NASA Astrophysics Data System (ADS)

    Wilson, A. M.; Williams, M. W.; Kayastha, R. B.; Hughes, H.

    2015-12-01

    Understanding the hydrology of glacierized catchments is an important step in assessing vulnerability of water resources to a changing climate. While there have been increased efforts recently to understand the dynamics of Asia's cryosphere, glacier melt dynamics and the contribution of melting ice to river discharge is open question. Tritium samples collected from water and ice in the Langtang Valley, Nepal in 2013, 2014 and 2015 offer new insights into relative age and residence times of different water sources in the basin, and seasonal changes in river water composition. With tritium values below detection limits in terminal glacier ice, values between 1 and 5 Tritium Units (TU) in spring water, and greater than 3 TU but declining with elevation in the Langtang River, the role of glacier melt in river hydrology can be compared to that estimated using oxygen-18 values in two component mixing models. Tritium results suggest that oxygen-18 mixing model results over-estimate glacier ice contributions to river discharge.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. Constraining back-arc basin formation in the eastern Coral Sea: preliminary results from the ECOSAT voyage

    NASA Astrophysics Data System (ADS)

    Seton, M.; Williams, S.; Mortimer, N. N.; Meffre, S.; Moore, J.; Micklethwaite, S.; Zahirovic, S.

    2013-12-01

    The eastern Coral Sea region is an underexplored area at the northeastern corner of the Australian plate, where long-lived interaction between the Pacific and Australian plate boundaries has resulted in an intricate assemblage of deep oceanic basins and ridges, continental fragments and volcanic products. A paucity of marine geophysical and geological data from this complex region has resulted in the lack of a clear conceptual framework to describe its formation, ultimately affecting our understanding of the connection between the plate boundaries of the SW Pacific and SE Asia. In particular, the tectonic relationship between two back-arc basins, the Santa Cruz and d'Entrecasteaux Basins, and the South Rennell Trough, has yet to be resolved. In October-November, 2012, we collected 6,200 km of marine magnetic, 6,800 km of gravity and over 13,600 km2 of swath bathymetry data from the eastern Coral Sea onboard the RV Southern Surveyor. A complementary dredging program yielded useful samples from 14 seafloor sites. Our preliminary geochemical interpretation of the dredge samples obtained from the South Rennell Trough reveal volcanic rocks resembling MORB or BABB-type basalts, similar in composition to the recently re-analysed and dated ORSTOM dredges from the area that yielded ~28 Ma MORB-like basalts. Swath bathymetry profiles from the Santa Cruz Basin reveal that the South Rennell Trough extends into this basin, with seafloor spreading fabric being parallel to the trough. Preliminary analysis of the three full and four partial new magnetic anomaly profiles across the Santa Cruz Basin, coupled with limited existing profiles, reveals that the basin may have formed between Chrons 13-18 (~32-38 Ma), with an extinct spreading ridge along the inferred continuation of the South Rennell Trough, consistent with ORSTOM age dates. Our results suggest that the South Rennell Trough is an extinct southwestward propagating spreading ridge, which may have initiated along a pre

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. Groundwater recharge processes in the Nasia sub-catchment of the White Volta Basin: Analysis of porewater characteristics in the unsaturated zone

    NASA Astrophysics Data System (ADS)

    Addai, Millicent Obeng; Yidana, Sandow Mark; Chegbeleh, Larry-Pax; Adomako, Dickson; Banoeng-Yakubo, Bruce

    2016-10-01

    Vertical infiltration of precipitation has been examined in this study for the purpose of evaluating groundwater recharge processes in parts of the Nasia sub-catchment of the White Volta Basin. As recharge is an essential component in the detailed assessment of groundwater resources potential in a basin, evaluating its processes is vital in determining the spatial and temporal variability of the resource. Stable isotope data of precipitation, groundwater, surface water and porewater in the area suggest that the local precipitation is largely enriched compared to global meteoric water. This is consistent with the prevailing local conditions in the region and ties in with observations in other parts of the sub-region. The groundwater and porewater data indicate that prior to, and in the process of infiltration and final percolation into the saturated zone, rainwater undergoes evaporative enrichment such that the finally recharged water plots along an evaporation line with a much shallower gradient and intercept compared to the global meteoric water line and the local meteoric water line. The isotope data further suggest that through the shallow unsaturated zone, a significant fraction of the initial precipitation would have been evaporated by a depth of 3.0 m. Evaporation rates in the range of 38-49% have been estimated for the depth range of 0-3.0 m based on the porewater stable isotope data. Details of the procedures and implications of high evaporation rates within such shallower depths are presented and discussed. Groundwater recharge rates estimated from the chloride mass balance technique report values in the range of 73.26 mm/yr (390 Mm3/yr)-109.89 mm/yr (585.27 Mm3/yr), with an average of 94 mm/yr (500.6 Mm3/yr). These translate into 6.6-10.9% of annual precipitation. Based on the current population trends and per capita water demand of 50 L per capita per day, this study finds that the estimated recharge rates exceed the demand 59 times. This suggests

  15. 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

  16. 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.

  17. 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.

  18. Deep seismic reflection profiling of sedimentary basins offshore Brazil: Geological objectives and preliminary results in the Sergipe Basin

    NASA Astrophysics Data System (ADS)

    Mohriak, Webster Ueipass; Lira Rabelo, JoséHenrique; De Matos, Renato Darros; De Barros, Mozart C.

    1995-12-01

    The first deep seismic reflection profiles offshore Brazil were acquired in Campos Basin and processed to 10 s TWT in 1984. Starting in 1989, Petrobrás acquired an extensive data set of deep seismic profiles using special acquisition equipment capable of effectively penetrating through the sedimentary layers and imaging the whole crustal architecture. These deep (18 s TWT) seismic reflection profiles extend across the Atlantic-type marginal basins, from the platform to the deepwater province, presently considered frontier regions for petroleum exploration. This work addresses the geological objectives of a deep seismic profile in the Sergipe Basin and discusses the results obtained by integrating regional seismic, gravity and magnetic data. When combined, these data provide evidence that deep seismic reflectors observed in the Sergipe Basin are related to intracrustal-upper mantle structures rather than sedimentary features. The deep seismic reflection profile in the Sergipe Basin also suggests that, rather than a non-volcanic passive margin, the deepwater extension of this basin is marked by several magmatic structures, including thick wedges of seaward-dipping reflectors and volcanic plugs. These magmatic features are associated with basinforming processes resulting from lithospheric extension during the breakup of Gondwana in the Early Cretaceous and subsequent emplacement of oceanic crust. These results are compared to the crustal scale structures observed in the Campos Basin, in the southeastern margin of Brazil. The interpretation of the deep structure of these basins indicates that final separation between the South American and African plates formed passive margins characterized by different patterns of crustal attenuation underlying the rift blocks.

  19. 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 μ atm (n=46), whereas the Solimoes and Negro rivers, in the state of Amazonas, showed values around 0.43 ± 0.08 μ atm (n=131). Atmospheric averages were approximately 0.34 ± 0.04 μ atm (n=58) and 0.32 ± 0.03 μ 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

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

    NASA Astrophysics Data System (ADS)

    Hlaváčová, I.; Halounová, L.; Svobodová, 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 Ervěnice 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.

  1. Catchment Very-High Frequency Hydrochemistry: the Critex Chemical House

    NASA Astrophysics Data System (ADS)

    Floury, P.; Gaillardet, J.; Tallec, G.; Blanchouin, A.; Ansart, P.

    2015-12-01

    Exploring the variations of river quality at very high frequency is still a big challenge that has fundamental implications both for understanding catchment ecosystems and for water quality monitoring. Within the French Critical Zone program CRITEX, we have proposed to develop a prototype called "Chemical House", applying the "lab on field" concept to one of the stream of the Orgeval Critical Zone Observatory. The Orgeval catchment (45 km2) is part of the Critical Zone RBV ("Réseau des bassins versants") network. It is a typical temperate agricultural catchment that has been intensively monitored for the last 50 years for hydrology and nutrient chemistry. Agricultural inputs and land use are also finely monitored making Orgeval an ideal basin to test the response of the Critical Zone to agricultural forcing. Geology consists of a typical sedimentary basin of Cenozoic age with horizontal layers of limestones, silcrete and marls, covered by a thin loamy layer. Two main aquifers are present within the catchment: the Brie and the Champigny aquifers. Mean runoff is 780 mm/yr. The Chemical House is a fully automated lab and installed directly along the river, which performs measurement of all major dissolved elements such as Na, Cl, Mg, Ca, NO3, SO4 and K every half hour. It also records all physical parameters (Temperature, pH, conductivity, O2 dissolved, Turbidity) of the water every minute. Orgeval Chemical House started to measure river chemistry on June 12, 2015 and has successfully now recorded several months of data. We will present the architecture of the Chemical House and the first reproducibility and accuracy tests made during the summer drought 2015 period. Preliminary results show that the chemical house is recoding significant nychtemeral (day/night) cycles for each element. We also observe that each element has its own behaviour along a day. First results open great prospects.

  2. Preliminary results of high resolution magneto-biostratigraphy of continental sequences in Chapala Basin, Southwestern Mexico

    NASA Astrophysics Data System (ADS)

    Mendez Cardenas, D. L.; Benammi, M.

    2007-05-01

    Chapala Lake is south from Guadalajara, Jalisco State (Southwestern Mexico). Belongs to a series of Pliocenic lakes along the Mexican Volcanic Belt. It is localized in the Chapala rift, and the entire area is controlled by the tectonic setting of the Colima, Tepic and Chapala rifts, constituting the triple junction rift-rift-rift. The deposits studied belong to volcanosedimentary sequences, composed by lacustrine and fluvial associations alternated with units of ash and pumice. The faunistic component reported consists at least of 27 mammals species, and the sediments were there're in have to work with special attention for seek rodents by handpicking. Probably these rodents will be the clue to determine the deposits correlation. Core demagnetization shows that they are low-coercivity magnetic minerals like magnetite or Ti-magnetite. It was verified that the characteristic magnetization corresponds to MNRp and the inversion test resulted good. Rodents are represented by Geomynae, Sigmondontinae and Sciurinae. The Geomynae family is the most common, and the faunistic association indicates Blancan age. This also allows a correlation with the polarity pattern in the GSS between 3,6 and 2,6 Ma. Actually, is known that this kind of studies in continental sequences supported with paleontological record of vertebrates could give us a more precised calibration of the age of such deposits. Allowing better understanding of the evolution of these mammals and their path trough geological record. This work shows the preliminary results of rodents palaeontology and high resolution magneto-stratigraphy in the units from to Chapala Basin.

  3. Coevolution of volcanic catchments in Japan

    NASA Astrophysics Data System (ADS)

    Yoshida, Takeo; Troch, Peter A.

    2016-03-01

    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 coevolution 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 and slope-area relationship) 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 a significant correlation between drainage density and baseflow index with age, but not with climate. The intra-annual flow variability was also significantly related to catchments age. Younger catchments tended to have lower peak flows and higher low flows, while older catchments exhibited more flashy runoff. The decrease in baseflow with catchment age is consistent with the existing hypothesis that in volcanic landscapes the major flow pathways change over time from deep groundwater flow to shallow subsurface flow. The drainage density of our catchments decreased with age, contrary to previous findings in a set of similar, but younger volcanic catchments in the Oregon Cascades, in which drainage density increased with age. In that case, older catchments were thought to show more landscape incision due to increasing near-surface lateral flow paths. Our results suggests two competing hypotheses on the evolution of drainage density in mature catchments. One is that as catchments continue to age, the hydrologically active channels retreat

  4. Inferring the effect of catchment complexity on mesoscale hydrologic response

    NASA Astrophysics Data System (ADS)

    FröHlich, Holger L.; Breuer, Lutz; Vaché, Kellie B.; Frede, Hans-Georg

    2008-09-01

    The effect of catchment complexity on hydrologic and hydrochemical catchment response was characterized in the mesoscale Dill catchment (692 km2), Germany. This analysis was developed using multivariate daily stream concentration and discharge data at the basin outlet, in connection with less frequently sampled catchment-wide end-member chemistries. The link between catchment-wide runoff sources and basin output was observed through a combination of concentration-discharge (C-Q) analysis and multivariate end-member projection. Subsurface stormflow, various groundwater and wastewater sources, as well as urban surface runoff emerged in catchment output chemistry. Despite the identification of multiple sources, several runoff sources observed within the catchment failed to display consistent links with the output chemistry. This failure to associate known source chemistry with outlet chemistry may have resulted from a lack of hydraulic connectivity between sources and basin outlet, from different arrival times of subbasin-scale runoff contributions, and also from an overlap of source chemistries that subsumed discrete runoff sources in catchment output. This combination of catchment heterogeneity and complexity simply suggests that the internal spatial organization of the catchment impeded the application of lumped mixing calculations at the 692 km2 outlet. Given these challenges, we suggest that in mesoscale catchment research, the potential effects of spatial organization should be included in any interpretation of highly integrated response signals, or when using those signals to evaluate numerical rainfall-runoff models.

  5. 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

  6. 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.

  7. 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.

  8. 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'érosion des sols et la sédimentation dans les zones humides associées durant l'Holocène ». 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 km²; 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

  9. Preliminary Stratigraphic Cross Sections of Oil Shale in the Eocene Green River Formation, Uinta Basin, Utah

    USGS Publications Warehouse

    Dyni, John R.

    2008-01-01

    Oil shale units in the Eocene Green River Formation are shown on two east-west stratigraphic sections across the Uinta Basin in northeastern Utah. Several units have potential value for recovery of shale oil, especially the Mahogany oil shale zone, which is a high grade oil shale that can be traced across most of the Uinta Basin and into the Piceance Basin in northwestern Colorado. Many thin medium to high grade oil shale beds above the Mahogany zone can also be traced for many miles across the basin. Several units below the Mahogany that have slow velocities on sonic logs may be low grade oil shale. These may have value as a source for shale gas.

  10. Sulfur in submarine eruptions: Observations and preliminary data from West Mata, NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Keller, N. S.; Rubin, K. H.; Clague, D. A.; Michael, P. J.; Resing, J. A.; Cooper, L. B.; Shaw, A. M.; Ono, S.; Tamura, Y.

    2009-12-01

    Sulfur in its various oxidation states is a major component of magmatic volatiles; its abundance and isotopic composition constrain degassing processes as well as sulfur sources, and have been used as a tool to study sulfur cycling at convergent plate margins. However, there are almost no sulfur isotope data on active submarine eruptions as such eruptions have only been witnessed in recent years. Little is known on the effect of water depth and eruptive processes on the isotopic composition of all sulfur-bearing phases, in particular on the relationship between δ33S and δ34S. Therefore, the active eruption observed at West Mata Volcano during a NOAA/NSF rapid response cruise to the NE Lau Basin in May 2009 provided a unique opportunity to study lavas, fluids and native sulfur from an ongoing submarine eruption. West Mata is situated about 40 km west of the northern termination of the Tonga Arc and its summit is at a water depth of 1193 m. Two main areas of active vents were discovered near the summit, named Hades and Prometheus. The observed eruptive processes consisted of pyroclastic activity and degassing at both vents; additionally, extrusion of tubular pillows was observed at Hades. The eruption plumes had a pronounced yellow color, due to the presence of large quantities of native sulfur globules. Five ROV Jason 2 dives on and around the summit area returned samples of pillows, sheet flows, spatter fragments, pyroclastic deposits, as well as gas and fluid samples. The pyroclastic deposits close to the vents contain numerous sulfur droplets, whereas sediment scoops taken further from the vents are free of native sulfur, suggesting that the droplets disintegrate and dissolve over time, so their presence may be a qualitative age indicator for the eruptive material. The sulfur globules are generally quasi perfect spheres up to 5 mm in diameter, mostly yellow, but sometimes pink, orange or grey. Several droplets were found to have elongated or twisted shapes

  11. BASINS

    EPA Pesticide Factsheets

    Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system designed to help regional, state, and local agencies perform watershed- and water quality-based studies.

  12. 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.

  13. 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.

  14. Preliminary data report for the San Juan Basin-Crownpoint surveillance study

    USGS Publications Warehouse

    Frenzel, Peter F.; Craigg, Steven D.; Padgett, Elizabeth T.

    1981-01-01

    Geohydrologic data that may be used to predict the effects of mining on Navajo water resources in the San Juan structural basin are reported as well as the current availability of data from other government agencies. Emphasis is on the vicinity of Crownpoint, New Mexico. (USGS)

  15. 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.

    2015-07-30

    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.

  16. 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.

  17. 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

    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.

  18. Preliminary evaluation of magnitude and frequency of floods in selected small drainage basins in Ohio

    USGS Publications Warehouse

    Kolva, J.R.

    1985-01-01

    A previous study of flood magitudes and frequencies in Ohio concluded that existing regionalized flood equations may not be adequate for estimating peak flows in small basins that are heavily forested, surface mined, or located in northwestern Ohio. In order to provide a large data base for improving estimation of flood peaks in these basins, 30 crest-stage gages were installed in 1977, in cooperation with the Ohio Department of Transportation, to provide a 10-year record of flood data The study area consists of two distinct parts: Northwestern Ohio, which contains 8 sites, and southern and eastern Ohio, which contains 22 sites in small forested or surface-mined drainage basins. Basin characteristics were determined for all 30 sites for 1978 conditions. Annual peaks were recorded or estimated for all 30 sites for water years 1978-82; an additional year of peak discharges was available at four sites. The 2-year (Q2) and 5-year (Q5) flood peaks were determined from these annual peaks.Q2 and Q5 values also were calculated using published regionalized regression equations for Ohio. The ratios of the observed to predicted 2-year (R2) and 5-year (R5) values were then calculated. This study found that observed flood peaks aree lower than estimated peaks by a significant amount in surface-mined basins. The average ratios of observed to predicted R2 values are 0.51 for basins with more than 40 percent surface-minded land, and 0.68 for sites with any surface-mined land. The average R5 value is 0.55 for sites with more than 40 percent surface-minded land, and 0.61 for sites with any surface-mined land. Estimated flood peaks from forested basins agree with the observed values fairly well. R2 values average 0.87 for sites with 20 percent or more forested land, but no surface-mined land, and R5 values average 0.96. If all sites with more than 20 percent forested land and some surface-mined land are considered, R2 the values average 0.86, and the R5 values average 0.82.

  19. 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.

  20. High frequency sampling of stable water isotopes for assessing runoff generation processes in a mesoscale urbanized catchment

    NASA Astrophysics Data System (ADS)

    Wrede, Sebastian; Fenicia, Fabrizio; Kurtenbach, Andreas; Keßler, Sabine; Bierl, Reinhard

    2013-04-01

    Experimental hydrology critically relies on tracer techniques to decipher and uncover runoff generation processes. Although tracer measurements contributed significantly to a better understanding of catchment functioning, their potential is not yet fully exploited. The temporal resolution of tracer measurements is typically relatively coarse, and applications are confined to a few locations. Additionally, experimental hydrology has focused primarily on pristine catchments, and the influence of anthropogenic effects remains largely unexplored. High frequency sampling of multiple tracers may therefore substantially enhance our understanding of hydrological processes and the impact of anthropogenic effects and enable a better protection and management of water resources and water quality. In this preliminary study we aim to assess runoff generation processes using geochemical and isotopic tracer techniques in the mesoscale Olewiger Bach catchment (24 km²) that is located in the low mountain ranges of the city of Trier, southwest Germany. The catchment is mainly characterized by quartzite and Devonian schist, overlain by fluvial sediments. Mixed land use prevails in the southern part of the basin, while the northern lower reaches are mainly urbanized. Several waste water treatment plants, separate sewer and stormwater management systems are present in parts of the catchment and contribute to the discharge of the main river. Tracer techniques employed in this ongoing study are twofold. A long term sampling of stable water isotopes (oxygen-18 and deuterium) was initiated in order to allow inferences about mean residence times of water in different catchment compartments, while event-based sampling using a multi-tracer approach was used to identify different runoff components and associated water pathways. Special attention is given to the observation of in-channel processes by assessing the dynamics of dissolved and particulate geochemical tracers and stable water

  1. Preliminary report on the ground-water resources of the Klamath River basin, Oregon

    USGS Publications Warehouse

    Newcomb, Reuben Clair; Hart, D.H.

    1958-01-01

    The Klamath River basin, including the adjacent Lost River basin, includes about 5,500 square miles of plateaus, mountain-slopes and valley plains in south-central Oregon. The valley plains range in altitude from about 4,100 feet in the south to more than 4,500 feet at the northern end; the mountain and plateau lands rise to an average altitude of 6,000 feet at the drainage divide, some peaks rising above 9,000 feet. The western quarter of the basin is on the eastern slope of the Cascade Range and the remainder consists of plateaus, mountains, and valleys of the basin-and-range type. The rocks of the Klamath River basin range in age from Recent to Mesozoic. At the southwest side of the basin in Oregon, pre-Tertiary metamorphic, igneous, and sedimentary rocks, which form extensive areas farther west, are overlain by sedimentary rocks of Eocene age and volcanic rocks of Eocene and Oligocene age. These early Tertiary rocks dip east toward the central part of the Klamath River basin. The complex volcanic rocks of high Cascades include three units: the lowest unit consists of a sequence of basaltic lava flows about 800 feet thick; the medial unit is composed of volcanic-sedimentary and sedimentary rocksthe Yonna formation200 to 2,000 feet thick; the uppermost unit is a sequence of basaltic lava flows commonly about 200 feet thick. These rocks dip east from the Cascade Range and are the main bedrock formations beneath most of the basin. Extensive pumice deposits, which emanated from ancestral Mount Mazama, cover large areas in the northwestern part of the basin. The basin has an overall synclinal structure open to the south at the California boundary where it continues as the Klamath Lake basin in California. The older rocks dip into the basin in monoclinal fashion from the adjoining drainage basins. The rocks are broken along rudely rectangular nets of closely spaced normal faults, the most prominent set of which trends northwest. The network of fault displacements

  2. Preliminary groundwater flow model of the basin-fill aquifers in Detrital, Hualapai, and Sacramento Valleys, Mohave County, northwestern Arizona

    USGS Publications Warehouse

    Tillman, Fred D; Garner, Bradley D.; Truini, Margot

    2013-01-01

    Preliminary numerical models were developed to simulate groundwater flow in the basin-fill alluvium in Detrital, Hualapai, and Sacramento Valleys in northwestern Arizona. The purpose of this exercise was to gather and evaluate available information and data, to test natural‑recharge concepts, and to indicate directions for improving future regional groundwater models of the study area. Both steady-state and transient models were developed with a single layer incorporating vertically averaged hydraulic properties over the model layer. Boundary conditions for the models were constant-head cells along the northern and western edges of the study area, corresponding to the location of the Colorado River, and no-flow boundaries along the bedrock ridges that bound the rest of the study area, except for specified flow where Truxton Wash enters the southern end of Hualapai Valley. Steady-state conditions were simulated for the pre-1935 period, before the construction of Hoover Dam in the northwestern part of the model area. Two recharge scenarios were investigated using the steady-state model—one in which natural aquifer recharge occurs directly in places where water is available from precipitation, and another in which natural aquifer recharge from precipitation occurs in the basin-fill alluvium that drains areas of available water. A transient model with 31 stress periods was constructed to simulate groundwater flow for the period 1935–2010. The transient model incorporates changing Colorado River, Lake Mead, and Lake Mohave water levels and includes time-varying groundwater withdrawals and aquifer recharge. Both the steady-state and transient models were calibrated to available water-level observations in basin-fill alluvium, and simulations approximate observed water-level trends throughout most of the study area.

  3. Runoff responses to forest thinning at plot and catchment scales in a headwater catchment draining Japanese cypress forest

    NASA Astrophysics Data System (ADS)

    Dung, Bui Xuan; Gomi, Takashi; Miyata, Shusuke; Sidle, Roy C.; Kosugi, Kenichiro; Onda, Yuichi

    2012-06-01

    SummaryWe 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 (catchment M5), and left the control catchment (M4) untreated. In both catchments, we monitored overland flow from hillslope plots and stream runoff from catchments at basin outlets over a 2-year pre-thinning period and a 2-year post-thinning period. Paired catchment analysis revealed that annual catchment runoff increased 240.7 mm after thinning. Delayed runoff increased significantly, while quick runoff followed similar patterns in the pre- and post-thinning periods. Flow duration in the ephemeral channel in catchment M5 increased from 56.9% in the pre-thinning period to 73.3% in the post-thinning period. Despite the changes in hydrological responses at the catchment scale, increases in overland flow were not significant. The increased availability of water in the soil matrix, caused by decreased interception loss and evapotranspiration, increased base flow after thinning. Based on the summarized data of previous studies together with this study, the effects of forest thinning on increases in runoff were less than partial harvesting in which the managed areas were concentrated within a watershed. We demonstrated that the effect of forest thinning was strongly scale dependent, an important finding for optimizing water and forest management in forested watersheds.

  4. 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

  5. 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

  6. Hydraulic Characteristics of the San Gregorio Creek Drainage Basin, California: a Preliminary Study.

    NASA Astrophysics Data System (ADS)

    Davis, J. R.; Snow, M. K.; Pestrong, R.; Sklar, L. S.; Vavro, M.; Sawachi, A.; Talapian, E.; Bailey, E.

    2004-12-01

    Population pressures within the greater San Francisco Bay Area are forcing development into nearby rural communities, and are impacting local environments. This study of the San Gregorio Creek Watershed is designed as a baseline for evaluating the effect increasing development within the drainage basin has on its river system. We hope to provide evidence for that impact through laboratory and field studies that provide a snap-shot of this drainage basin's current characteristics. The San Gregorio Creek watershed, in the Coast Ranges, is located in the southwestern portion of San Mateo County, California. It drains the western slopes of the Santa Cruz Mountains, in the Coast Ranges into the Pacific Ocean at the town of San Gregorio. Most of its fingertip tributaries flow into the trunk from the north and west, with elevations as high as 2050 feet. The watershed includes an area of approximately 51.6 square miles and San Gregorio Creek, the trunk stream, is roughly 12 miles long. San Gregorio Creek is a fourth order perennial stream. It is fed by a number of major tributaries, the largest of which are Alpine, Mindego, and La Honda creeks. The U.S. Geological Survey maintains a stream gauging station for San Gregorio Creek at the town of San Gregorio, where it has been monitoring stream flows for more than 30 years through its Water Resources Department. The resulting data indicate a mean discharge of 36.4 cfs. Map studies of hydraulic geometry for the drainage basin reveal geometric characteristics for San Gregorio Creek that coincide with similar streams in comparable climatic and environmental settings. Stream table studies are used to further investigate fundamental stream processes. Field studies at selected reaches throughout the drainage basin will document hydraulic characteristics. The results of this study will contribute to more comprehensive studies demonstrateing channel response to changing environmental conditions.

  7. 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.

  8. 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.

  9. 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

  10. Preliminary Classification of Water Areas Within the Atchafalaya Basin Floodway System by Using Landsat Imagery

    USGS Publications Warehouse

    Allen, Yvonne C.; Constant, Glenn C.; Couvillion, Brady R.

    2008-01-01

    The southern portion of the Atchafalaya Basin Floodway System (ABFS) is a large area (2,571 km2) in south central Louisiana bounded on the east and west sides by a levee system. The ABFS is a sparsely populated area that includes some of the Nation's most significant extents of bottomland hardwoods, swamps, bayous, and backwater lakes, holding a rich abundance and diversity of terrestrial and aquatic species. The seasonal flow of water through the ABFS is critical to maintaining its ecological integrity. Because of strong interdependencies among species, habitat quality, and water flow in the ABFS, there is a need to better define the paths by which water moves at various stages of the hydrocycle. Although river level gages have collected a long historical record of water level variation, very little synoptic information has been available regarding the distribution and character of water at more remote locations in the basin. Most water management plans for the ABFS strive to improve water quality by increasing water flow and circulation from the main stem of the Atchafalaya River into isolated areas. To describe the distribution of land and water on a basin-wide scale, we chose to use Landsat 5 and Landsat 7 imagery to determine the extent of water distribution from 1985 to 2006 and at a variety of river stages. Because the visual signature of river water is high turbidity, we also used Landsat imagery to describe the distribution of turbid water in the ABFS. The ability to track water flow patterns by tracking turbid waters will enhance the characterization of water movement and aid in planning.

  11. Rhaetian extensional tectonics in the Slovenian Basin (Southern Alps): Preliminary results of an outcrop study

    NASA Astrophysics Data System (ADS)

    Oprčkal, P.; Gale, L.; Kolar-Jurkovšek, T.; Rožič, B.

    2012-04-01

    A Late Triassic palaeogeographic position of the Slovenian Basin on the passive continental margin of the Neotethys Ocean to the East and later the Alpine Tethys to the West, implements that its evolution intimately depended on the events in these two areas of extension. Recent research of the "Bača dolomite", the typical Norian-Rhaetian lithologic unit of the Slovenian Basin, resulted in recognition of four extensional tectonic events (Gale et al., this volume). The Lower and Middle Norian tectonic pulses can be recognized throughout the basin. A weakened tectonic activity was recognized in the Rhaetian, followed by more pronounced, but spatially restricted tectonics at the Triassic-Jurassic boundary. Extensional tectonics was attributed to the diminishing rifting in the Neotethys area and to the incipient opening of the Alpine Tethys (Gale et al., this volume). The ongoing fieldwork in the vicinity of Škofja Loka (central Slovenia) resulted in the discovery of palaeofaults in the small-sized quarry that directly evidences the Late Triassic extensional tectonics. Based on superposition, the observed section of the "Bača dolomite" is of the Rhaetian age. The discovery is particularly important because it represents the first direct documentation of the Late Triassic down-faulting in the region. The lowest strata exposed consist of highly bituminous bedded dolostones with scour structures and several meters of mud-supported dolo-breccias. Breccias were downthrown along a normal fault and the created accommodation space filled with bedded dolostone. After complete leveling of topography, another differentiation took place, during which a new normal fault originated, whereas the pre-existing fault was reactivated in an antithetic sense. Thin-bedded dolostones were deposited during slowly abiding movements. The final cessation of tectonics is marked by a uniform deposition of massive dolostone, entirely overlying the fault-dissected sediments.

  12. 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.

  13. 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

  14. 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)

    Séguis, L.; Kamagaté, B.; Favreau, G.; Descloitres, M.; Seidel, J.-L.; Galle, S.; Peugeot, C.; Gosset, M.; Le Barbé, 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 Ouémé 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 Ouémé valley, which can be considered as representative of sub-humid Sudanian rivers flowing on a crystalline

  15. Modeling the impact of development and management options on future water resource use in the Nyangores sub-catchment of the Mara Basin in Kenya

    NASA Astrophysics Data System (ADS)

    Omonge, Paul; Herrnegger, Mathew; Fürst, Josef; Olang, Luke

    2016-04-01

    Despite the increasing water insecurity consequent of competing uses, the Nyangores sub-catchment of Kenya is yet to develop an inclusive water use and allocation plan for its water resource systems. As a step towards achieving this, this contribution employed the Water Evaluation and Planning (WEAP) system to evaluate selected policy based water development and management options for future planning purposes. Major water resources of the region were mapped and quantified to establish the current demand versus supply status. To define a reference scenario for subsequent model projections, additional data on urban and rural water consumption, water demand for crop types, daily water use for existing factories and industries were also collated through a rigorous fieldwork procedure. The model was calibrated using the parameter estimation tool (PEST) and validated against observed streamflow data, and subsequently used to simulate feasible management options. Due to lack of up-to-date data for the current year, the year 2000 was selected as the base year for the scenario simulations up to the year 2030, which has been set by the country for realizing most flagship development projects. From the results obtained, the current annual water demand within the sub-catchment is estimated to be around 27.2 million m3 of which 24% is being met through improved and protected water sources including springs, wells and boreholes, while 76% is met through informal and unprotected sources which are insufficient to cater for future increases in demand. Under the reference scenario, the WEAP model predicted an annual total inadequate supply of 8.1 million m3 mostly in the dry season by the year 2030. The current annual unmet water demand is 1.3 million m3 and is noteworthy in the dry seasons of December through February at the irrigation demand site. The monthly unmet domestic demand under High Population Growth (HPG) was projected to be 1.06 million m3 by the year 2030. However

  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

  17. 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.

  18. Preliminary study of the hydrologic response of an urban drainage basin at two different scales

    NASA Astrophysics Data System (ADS)

    Ferreira, Carla; Ferreira, António; Coelho, Celeste; de Lima João, Pedroso

    2010-05-01

    Predicted changes in climate and urban sprawl areas are expected to cause significant modification in rainfall pattern and hydrological regimes. Urbanization can alter the hydrologic response by increasing streamflow, reducing time of concentration, altering soil moisture levels and increasing overland flow, thereby increasing the size, frequency and speed of peak flow responses. However, despite the profusion of works, effective methodologies to investigate the impacts of potential land-use change on how spatial variability of soil moisture and precipitation affect runoff production at a range of scales and on different land uses remain largely undeveloped. This has important implications for flood prediction accuracy. The main aim of this work is to assess the hydrological response and to understand the influence of different land uses. The study is based on a small urban drainage basin (7 Km2), undergoing rapid urbanization, located in central Portugal: Ribeira dos Covões. It considers a combined approach of field survey and data acquisition to access spatiotemporal dynamics and land uses contributions to surface hydrology, based on drainage basins and small plot scales. At drainage basin scale, the study is based on three years rainfall and stream flow data analysis (collected through an automatic water level recorder and rain gauges). Rainfall-runoff relationship was assessed over the time and isolated events were studied. To understand land uses on the hydrology, rainfall simulations were conducted at the small plot scale (0.25 m2) during a dry period, in forested and deforested areas, agricultural areas, including tilled and abandoned areas, as well as built-up areas (21 experiments with 1 hour duration, with a rain intensity of 43±3 mm h-1). During the experiments hydrophobicity was monitored (Molarity of an Ethanol Droplet technique), soil moisture content was assessed every minute, and runoff volume was measured every 5 minutes. This work has shown the

  19. Preliminary spectral and geologic analysis of Landsat-4 Thematic Mapper data, Wind River Basin area, Wyoming

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    A Landsat-4 Thematic Mapper (TM) image of the Wind River Basin area in Wyoming is currently under analysis for stratigraphic and structural mapping and for assessment of spectral and spatial characteristics using visible, near infrared, and short wavelength infrared bands. To estimate the equivalent Lambertian surface reflectance, TM radiance data were calibrated to remove atmospheric and instrumental effects. Reflectance measurements for homogeneous natural and cultural targets were acquired about one year after data acquisition. Calibration data obtained during the analysis were used to calculate new gains and offsets to improve scanner response for earth science applications. It is shown that the principal component images calculated from the TM data were the result of linear transformations of ground reflectance. In images prepared from this transform, the separation of spectral classes was independent of systematic atmospheric and instrumental factors. Several examples of the processed images are provided.

  20. Uranium in the Poison Basin area, Carbon County, Wyoming - a preliminary report

    USGS Publications Warehouse

    Vine, James D.; Prichard, George E.

    1953-01-01

    Uranium minerals were found on October 15, 1953, about seven miles west of Baggs in the Browns Park formation of the Poison Basin area, Carbon County, Wyo. The occurrences extend over an area of at least several square miles in secs. 4 and 5, T. 12 N., R. 92 W., and secs. 32 and 33, T. 13 N., R. 92 W. Uranophane-bearing sandstones contain as much as 3.21 percent uranium in select samples. The occurrences cannot be evaluated because their dimensions and average grade have not been determined. The presence of uranium, however, is significant because it indicates that uranium deposits may be present in the Browns Park formation and also in the underlying formations unconformably overlapped by the Browns Park.

  1. 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

  2. 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

    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.

  3. Luminescence Dating of Marine Terrace Sediments Between Trabzon and Rize, Eastern Black Sea Basin: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Softa, Mustafa; Spencer, Joel Q. G.; Emre, Tahir; Sözbilir, Hasan; Turan, Mehmet

    2016-04-01

    Quaternary marine terraces in the coastal region of Pontides in Northeastern Turkey are valuable archives of past sea level change. Until recently, dates of raised marine terraces undeciphered in the coastal region between Trabzon and Rize because of chronologic limitations. In this paper was to determine ages of the terrace deposits by applying optically stimulated luminescence (OSL) dating methods using single aliquot regenerative dose (SAR) techniques on quartz minerals from extracted marine terraces. Several samples were collected from three orders of Quaternary marine terraces which are reproducible at all sampling location in between cities of Trabzon and Rize, Turkey, coastal of Eastern Pontides, at the front of the thrust system. The terrace deposits mainly consist of clays, silts, sands and gravels. The sediments in these deposits are mainly derived from basaltic, andesitic, and limestone geology, and have elipsoid, square and flat shapes. The terrace deposits have heights ranging from 1 to 17 meters and increases in height and thickness from west to east. Initial OSL results from 1 mm and 3 mm quartz aliquots demonstrate good luminescence characteristics. Preliminary equivalent dose analysis results ranging from 17.6 Gy to 79.6 Gy have been calculated using the Central Age Model (CAM) and Minimum Age Model (MAM). According to ages obtained from three separate terrace is ~8 ka, ~42 ka and ~78 ka, respectively. Results of marine terrace sediments indicate this region has three sedimentation periods and coastal region of Pontides has been remarkably tectonically active since latest Pleistocene to earlier Holocene. This study will present preliminary OSL dating results obtained from samples of Quaternary marine terrace formation. Keywords: optically stimulated luminescence (OSL) dating, single grain, marine terraces, Eastern Pontides.

  4. 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

  5. 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.

  6. Analyzing the effect of cryosphere processes on catchment hydrology through a modeling approach: a case study in the Heihe River basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Yang, D.; Gao, B.; Wang, Y.

    2015-12-01

    Understanding the changes in cryosphere processes on river discharge under climate change is very important for the water resources management in the high altitude cold regions. A distributed eco-hydrological model was developed and cryosphere processes were coupled with hydrological processes in the model simulation. Model validation shows that the model shows high skill in simulating the river discharge, soil moisture, soil temperature and heat flux. The study area is the Heihe River basin, the second largest inland river basin in China. Numerical experiment shows that the soil freezing/thawing shows significant impact of hydrological processes and it reduced base flow and increased peak flow. Hydrological changes of the past 50 years in the Heihe River were analyzed based on model simulation. Soil temperature was found to be increased and melting depth shows significant increasing trend. Due to the limited areas, glacier melting shows little impact on the runoff changes. However, the changes in frozen soil and the snow melting shows significant effects on the river discharge changes. The results highlights the importance of study of the cryosphere hydrology in understanding the hydrological changes in the high altitude cold regions. Key words: the Heihe River basin, hydrological changes, Cryosphere processes

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.; Nielson, Dennis 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.

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

    PubMed

    Barroso, Francisco R G; Viana, Maria Somália 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 Pacujá Municipality, northwestern state of Ceará) 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 Ceará to Brazilian and global palaeontology.

  13. Development and preliminary application of a method to assess river ecological status in the Hai River Basin, north China.

    PubMed

    Shan, Baoqing; Ding, Yuekui; Zhao, Yu

    2016-01-01

    The river ecosystem in the Hai River Basin (HRB), an important economic region in China, is seriously degraded. With the aim of river restoration in the HRB, we developed a method to assess the river's ecological status and conducted a preliminary application of the method. The established method was a predictive model, which used macroinvertebrates as indicator organisms. The river's ecological status was determined by calculating the ratio of observed to expected values (O/E). The method included ecoregionalization according to natural factors, and the selection of reference sites based on combinations of habitat quality and macroinvertebrate community. Macroinvertebrate taxa included Insecta, Crustacea, Gastropoda, and Oligochaeta, with 39 families and 95 genera identified in the HRB. The HRB communities were dominated by pollution tolerant taxa, such as Lymnaeidae, Chironomus, Limnodrilus, Glyptotendipes, and Tubifex. The average Shannon-Wiener index was 1.40±0.5, indicating a low biodiversity. In the river length of 3.31×10(4) km, 55% of the sites were designated poor, with a bad ecological status. Among nine secondary river systems, Luan and Zi-ya had the best and worst river conditions, respectively. Only 17 reference site groups were selected for river management in the 41 ecoregions examined. This study lays the foundation for river restoration and related research in the HRB, and we anticipate further developments of this novel method.

  14. Using self-organizing maps to infill missing data in hydro-meteorological time series from the Logone catchment, Lake Chad basin.

    PubMed

    Nkiaka, E; Nawaz, N R; Lovett, J C

    2016-07-01

    Hydro-meteorological data is an important asset that can enhance management of water resources. But existing data often contains gaps, leading to uncertainties and so compromising their use. Although many methods exist for infilling data gaps in hydro-meteorological time series, many of these methods require inputs from neighbouring stations, which are often not available, while other methods are computationally demanding. Computing techniques such as artificial intelligence can be used to address this challenge. Self-organizing maps (SOMs), which are a type of artificial neural network, were used for infilling gaps in a hydro-meteorological time series in a Sudano-Sahel catchment. The coefficients of determination obtained were all above 0.75 and 0.65 while the average topographic error was 0.008 and 0.02 for rainfall and river discharge time series, respectively. These results further indicate that SOMs are a robust and efficient method for infilling missing gaps in hydro-meteorological time series.

  15. Southern Great Basin seismological data report for 1981 and preliminary data analysis

    SciTech Connect

    Rogers, A.M.; Harmsen, S.C.; Carr, W.J.; Spence, W.

    1983-09-01

    Earthquake data for the calendar year 1981 are reported for earthquakes occurring within and adjacent to the southern Great Basin seismograph network. Locations, magnitudes, and selected focal mechanisms for these events and events from prior years of network operations are presented and discussed in relation to the geologic framework of the region. These data are being collected to aid in the evaluation of the seismic hazard to a potential repository site at Yucca Mountain in the southwestern Nevada Test Site. The regional stress field orientation, as inferred from focal mechanisms, is characterized by a northwest-directed least compressive stress and a northeast-directed greatest compressive stress. We infer from this stress orientation that faults of north to northeast trend are most susceptible to slip. Faults of this orientation exist within the Yucca Mountain block, but they probably have not moved significantly in the last 500,000 years. Yucca Mountain lies within a fairly large area of relatively low level seismicity extending west to the Funeral Mountains, south of the Black Mountains and Nopah Range, and southeast to the Spring Mountains. One M 1.7 earthquake has been located in the Yucca Mountain block in about 1 year of intense monitoring. At present somewhat conflicting geologic, seismologic, and stress evidence hinder definitive conclusions about the seismic hazard at the proposed repository site. 36 references, 18 figures, 1 table.

  16. 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).

  17. The influence of sediment supply on arroyo cut-fill dynamics: a preliminary dataset of catchment averaged erosion rates calculated from in-situ 10Be

    NASA Astrophysics Data System (ADS)

    Riley, K. E.; Rittenour, T. M.

    2014-12-01

    Widespread and near-synchronous post-settlement stream entrenchment (arroyo cutting) in the southwest US stimulated research addressing forcing mechanisms and necessary geomorphic and climate conditions leading to episodic evacuations of valley-fill alluvium. Arroyos are an end-member channel form associated with ephemeral streams entrenched into cohesive, fine-grained, valley-fill. Historic arroyo entrenchment exposed 5-30 m of unconformity-bound packages of different aged Holocene alluvium. Chronostratigraphic reconstructions indicate that during the mid-late Holocene these systems underwent multiple periods of rapid episodic entrenchment followed by slow re-aggradation. Previous and ongoing work has developed alluvial chronostratigraphies of Kanab Creek, Johnson Wash, and surrounding streams in southern UT using a combination of stratigraphic relationships, radiocarbon, and single-grain OSL dating. This research investigates the role of allogenic forcing (climate change) and autogenic processes on cut-fill dynamics. This study tests if temporal or spatial variations in sediment supply have influenced the timing and location of arroyo aggradation and entrenchment. We measured in-situ 10-Be in quartz from alluvial and colluvial sediment in Kanab Creek and Johnson Wash to quantify catchment-average erosion rates. Samples were collected from modern channels throughout the watershed and from dated alluvial packages preserved in arroyo walls. Results quantify spatial and temporal variability in sediment supply throughout the two watersheds as a function of lithology, slope, elevation, contribution of sediment stored in valley-fill, and time. Moreover, 10-Be results from dated Holocene alluvium will be used to evaluate if climate change has influenced sediment supply and arroyo cut-fill dynamics.

  18. Preliminary assessment of water quality in the alluvial aquifer of the Puerco River basin, Northeastern Arizona

    USGS Publications Warehouse

    Webb, R.H.; Rink, G.R.; Radtke, D.B.

    1987-01-01

    The quality of groundwater in the alluvial aquifer of the Puerco River basin, northeastern Arizona, was evaluated in order to assess potential contamination from uranium mining and milling operations in New Mexico. A total of 14 wells and 1 spring were sampled to determine if a contaminant plume of radionuclides or trace elements is present. The water is characterized by high dissolved solids with a median of 698 mg/l and high concentrations of alkalinity, sodium, and sulfate. Except for iron, manganese, and strontium, the concentrations of trace elements generally are below the applicable EPA and State of Arizona maximum contaminant levels. Gross alpha activity has a median of 27 picocuries/l and ranges from 4 to 42 picocuries/l. Uranium, which accounts for most of the gross alpha activity, has a median concentration of 19 micrograms/l and ranges from 1 to 38 micrograms/l. Twenty percent to 84% of the gross alpha activity was derived from other undetermined radionuclides. Other radionuclides, including radium-226 and radium-228, generally are not present in activities > 5 picocuries/l in the water. Statistical analysis of the water quality data suggest that no contaminant plume can be defined on the basis of samples from existing wells. The contamination in the alluvial aquifer apparently does not change in the downstream direction along the Puerco River. The geochemistry of radionuclides indicates that most radionuclides from the uranium-decay series are immobile or only slightly mobile, whereas uranium will not precipitate out of solution but may be removed by sorption in the alluvial aquifer. (Author 's abstract)

  19. On Radar Rainfall, Catchment Runoff and the Response Scale

    NASA Astrophysics Data System (ADS)

    Morin, E.; Goodrich, D. C.; Gao, X.; Sorooshian, S.

    2001-12-01

    The general research hypothesis is that: "a rainfall event, extreme at a specific scale, has the potential to generate an extreme runoff event in a catchment, which characterized by this response scale". In the presented study, which is a first step in testing this hypothesis, we examine if catchments have a stable response scale in the above context. For that purpose, we compare maximum storm rainfall intensities at different time and space scales with runoff peak discharges in order to determine at what scale these two variables are best related to each other. Three types of rainfall variable are tested: 1) gage rainfall intensity, 2) radar rainfall intensity, and 3) radar reflectivity. Initial results are available for the Walnut Gulch Experimental Catchment, a 150-km2 semi-arid catchment, located in southern Arizona. The catchment is well equipped with dense networks of rainfall and runoff gages. Radar data are also available for the catchment from the Tucson NEXRAD system. Preliminary results indicate a response scale in the order of 6-km and 2-hours for the 150-km2 catchment and for the 126- and 94-km2 sub-catchments. The response scale of a 25-km2 sub-catchment is reduced to 1-km and 20-minutes. The three types of rainfall variable tested point to the same response scale. As mentioned, the above results are initial and based on a limited number of events. We are investigating this hypothesis on a larger number of events as well as additional catchments.

  20. 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.

  1. 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...

  2. 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

  3. The cosmogenic record of mountain erosion transmitted across a foreland basin: Source-to-sink analysis of in situ10Be, 26Al and 21Ne in sediment of the Po river catchment

    NASA Astrophysics Data System (ADS)

    Wittmann, Hella; Malusà, Marco G.; Resentini, Alberto; Garzanti, Eduardo; Niedermann, Samuel

    2016-10-01

    We analyze the source-to-sink variations of in situ10Be, 26Al and 21Ne concentrations in modern sediment of the Po river catchment, from Alpine, Apennine, floodplain, and delta samples, in order to investigate how the cosmogenic record of orogenic erosion is transmitted across a fast-subsiding foreland basin. The in situ10Be concentrations in the analyzed samples range from ∼ 0.8 ×104 at /gQTZ to ∼ 6.5 ×104 at /gQTZ. The 10Be-derived denudation rates range from 0.1 to 1.5 mm/yr in the Alpine source areas and from 0.3 to 0.5 mm/yr in the Apenninic source areas. The highest 10Be-derived denudation rates are found in the western Central Alps (1.5 mm/yr). From these data, we constrain a sediment flux leaving the Alpine and the Apenninic source areas (>27 Mt/yr and ca. 5 Mt/yr, respectively) that is notably higher than the estimates of sediment export provided by gauging (∼10 Mt/yr at the Po delta). We observe a high variability in 10Be concentrations and 10Be-derived denudation rates in the source areas. In the Po Plain, little variability is observed, and at the same time, the area-weighed 10Be concentration of (2.29 ± 1.57) ×104 at /gQTZ (±1 SD of the dataset) from both the Alps and the Apennines is poorly modified (by tributary input) in sediment of the Po Plain ((2.68 ± 0.78 , ± 1 SD) ×104 at /gQTZ). The buffering effect of the Po floodplain largely removes scatter in 10Be signals. We test for several potential perturbations of the cosmogenic nuclide record during source to sink transfer in the Po basin. We find that sediment trapping in deep glacial lakes or behind dams does not significantly change the 10Be-mountain record. For example, similar 10Be concentrations are measured upstream and downstream of the postglacial Lake Maggiore, suggesting that denudation rates prior to lake formation were similar to today's. On the scale of the entire basin, the 10Be concentration of basins with major dams is similar to those without major dams. A potential

  4. A multi-proxy lake core record from Lago Lungo, Rieti Basin, Lazio, Italy and its relation to human activities in the catchment during the last century

    NASA Astrophysics Data System (ADS)

    Noble, Paula; Tunno, Irene; Mensing, Scott; Piovesan, Gianluca

    2016-04-01

    The lakes of the Rieti Basin have experienced extensive human modification dating back to pre-Roman times, yet lake archives indicate that the most profound changes to the aquatic ecosystem have occurred during the last century. Analysis of the upper ˜120 cm segment of a sediment core from Lago Lungo, dating back to ˜1830 CE, show changes in water quality and hydrologic inflow largely attributed to 20th century reclamation and land use activities. Lago Lungo is a shallow, small, eutrophic, hard water lake situated in an intermontaine alluvial plain ˜90 km NE of Rome. It is one of several remnant lakes in a poorly drained wetland area fed by numerous springs. Reclamation activities over the last century have substantially altered the drainage network affecting water delivery to the lakes and their connectivity. There are 3 interesting signals in the core. First, small Stephanodiscus species, associated with hypereutrophic conditions, appear after 1950, peak ˜1990, and may be attributed to increased use of chemical fertilizers and intensification of local agriculture. Elemental proxies from scanning XRF data (abundances of Ti, Si/Ti, and Ca) are consistent with increased eutrophication starting ˜1950. A decline in Stephanodicsus after 1990 reflects some improvement to the water quality following the lake's incorporation into a nature preserve and creation of a narrow vegetation buffer. Intermittent water quality measurements from 1982 onward corroborate the changes in trophic status interpreted from the core record. Second, a large change in the core stratigraphy, elemental geochemistry, and diatom composition occurs ˜1940 and is associated with several major reclamation efforts, including the rerouting of the Santa Susanna channel, which redirected large volumes of artesian inflows away from the lakes and estuarine system. Upstream, dams on the Turano and Salto rivers were also constructed, further affecting hydrological inflows into the basin. From ˜1900

  5. Preliminary measurements of summer nitric acid and ammonia concentrations in the Lake Tahoe Basin air-shed: implications for dry deposition of atmospheric nitrogen.

    PubMed

    Tarnay, L; Gertler, A W; Blank, R R; Taylor, G E

    2001-01-01

    Over the past 50 years, Lake Tahoe, an alpine lake located in the Sierra Nevada mountains on the border between California and Nevada, has seen a decline in water clarity. With significant urbanization within its borders and major urban areas 130 km upwind of the prevailing synoptic airflow, it is believed the Lake Tahoe Basin is receiving substantial nitrogen (N) input via atmospheric deposition during summer and fall. We present preliminary inferential flux estimates to both lake surface and forest canopy based on empirical measurements of ambient nitric acid (HNO3), ammonia (NH3), and ammonium nitrate (NH4NO3) concentrations, in an effort to identify the major contributors to and ranges of atmospheric dry N deposition to the Lake Tahoe Basin. Total flux from dry deposition ranges from 1.2 to 8.6 kg N ha-1 for the summer and fall dry season and is significantly higher than wet deposition, which ranges from 1.7 to 2.9 kg N ha-1 year-1. These preliminary results suggest that dry deposition of HNO3 is the major source of atmospheric N deposition for the Lake Tahoe Basin, and that overall N deposition is similar in magnitude to deposition reported for sites exposed to moderate N pollution in the southern California mountains.

  6. 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.

  7. Controls on Water Storage, Mixing and Release in a Nested Catchment Set-up with Clean and Mixed Physiographic Characteristics

    NASA Astrophysics Data System (ADS)

    Pfister, L.; McDonnell, J.; Hissler, C.; Martínez-Carreras, N.; Klaus, J.

    2015-12-01

    With catchment water storage being only rarely determined, storage dynamics remain largely unknown to date. However, storage bears considerable potential for catchment inter-comparison exercises, as well as it is likely to have an important role in regulating catchment functions. Catchment comparisons across a wide range of environments and scales will help to increase our understanding of relationships between storage dynamics and catchment processes. With respect to the potential of catchment storage for bringing new momentum to catchment classification and catchment processes understanding we currently investigate spatial and temporal variability of dynamic storage in a nested catchment set-up (16 catchments) of the Alzette River basin (Luxembourg, Europe), covering a wide range of geological settings, catchment areas, contrasted landuse, and hydro-meteorological and tracer series. We define catchment storage as the total amount of water stored in a control volume, delimited by the catchment's topographical boundaries and depth of saturated and unsaturated zones. Complementary storage assessments (via input-output dynamics of natural tracers, geographical sounding, groundwater level measurements, soil moisture measurements, hydrometry) are carried out for comparison purposes. In our nested catchment set-up we have (1) assessed dependencies between geology, catchment permeability and winter runoff coefficients, (2) calculated water balance derived catchment storage and mixing potential and quantified how dynamic storage differs between catchments and scales, and (3) examined how stream baseflow dD (as a proxy for baseflow transit time) and integrated flow measures (like the flow duration curve) relate to bedrock geology. Catchments with higher bedrock permeability exhibited larger storage capacities and eventually lower average winter runoff coefficients. Over a time-span of 11 years, all catchments re-produced the same winter runoff coefficients year after year

  8. Regional stochastic estimation of the groundwater catchment for distributed hydrological modelling

    NASA Astrophysics Data System (ADS)

    Wöhling, Th.; Samaniego, L.; Selle, B.; Kumar, R.; Zink, M.

    2012-04-01

    Rainfall-runoff modeling typically assumes that the groundwater catchment boundary coincide with the topographic one. While this is often a reasonable assumption for large and and mesoscale catchments (> 103 km2), this assumption may lead to large errors of streamflow in small scale catchments (≤ 102 km2), in particular in certain geological settings. The Ammer catchment (135 km2) in the upper Neckar river basin (Germany) is a prime example where groundwater and topographic catchment boundaries are significantly distinct from each other. The catchment is characterized by a complex sequence of fractured, karstic Triassic rock formations. These strata gently dip into ESE direction governing groundwater flow. Analysis of tracer experiments conducted in the 1970s indicates that the boundary overlap could be less than 80 percent. Further, a modelling study of the upper Neckar river basin using the distributed hydrological model mHM showed Nash-Sutcliff efficiencies (NSE) < 0.4 for simulated runoff in the Ammer sub-basin whereas higher efficiencies (NSE ~ 0.7) were obtained for most of the other 21 sub basins in the region. In this study we present a methodology to simultaneously estimate the regional groundwater catchment boundaries of the Ammer and its surrounding basins. In a first step we derive the best possible fit between mHM simulated and observed runoff for the individual sub-basins in the Ammer region and determine the trade-off between the fits of the individual basins using the muliobjective optimization method AMALGAM. We further present a strategy to estimate the regional groundwater catchment boundaries with the aim to improve runoff predictions in the Ammer catchment while not deteriorating runoff predictions in the surrounding basins. Our strategy involves a modification of the mHM model to account for ground water import/export from neighboring catchments while maintaining full mass balance of the surrounding basins. Groundwater catchment boundaries

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. Preliminary assessment of channel stability and bed-material transport in the Rogue River basin, southwestern Oregon

    USGS Publications Warehouse

    Jones, Krista L.; O'Connor, Jim E.; Keith, Mackenzie K.; Mangano, Joseph F.; Wallick, J. Rose

    2012-01-01

    This report summarizes a preliminary assessment of bed-material transport, vertical and lateral channel changes, and existing datasets for the Rogue River basin, which encompasses 13,390 square kilometers (km2) along the southwestern Oregon coast. This study, conducted to inform permitting decisions regarding instream gravel mining, revealed that: * The Rogue River in its lowermost 178.5 kilometers (km) alternates between confined and unconfined segments, and is predominately alluvial along its lowermost 44 km. The study area on the mainstem Rogue River can be divided into five reaches based on topography, hydrology, and tidal influence. The largely confined, active channel flows over bedrock and coarse bed material composed chiefly of boulders and cobbles in the Grants Pass (river kilometers [RKM] 178.5-152.8), Merlin (RKM 152.8-132.7), and Galice Reaches (RKM 132.7-43.9). Within these confined reaches, the channel contains few bars and has stable planforms except for locally wider segments such as the Brushy Chutes area in the Merlin Reach. Conversely, the active channel flows over predominately alluvial material and contains nearly continuous gravel bars in the Lobster Creek Reach (RKM 43.9-6.7). The channel in the Tidal Reach (RKM 6.7-0) is also alluvial, but tidally affected and unconfined until RKM 2. The Lobster Creek and Tidal Reaches contain some of the most extensive bar deposits within the Rogue River study area. * For the 56.6-km-long segment of the Applegate River included in this study, the river was divided into two reaches based on topography. In the Upper Applegate River Reach (RKM 56.6-41.6), the confined, active channel flows over alluvium and bedrock and has few bars. In the Lower Applegate River Reach (RKM 41.6-0), the active channel alternates between confined and unconfined segments, flows predominantly over alluvium, shifts laterally in unconfined sections, and contains more numerous and larger bars. * The 6.5-km segment of the lower

  14. 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).

  15. Stratigraphic Evolution of Brazos-Trinity Basin IV, Western Gulf of Mexico: Preliminary Results of IODP Expedition 308

    NASA Astrophysics Data System (ADS)

    Pirmez, C.; Behrmann, J.; Flemings, P. B.; John, C.

    2005-12-01

    IODP Expedition 308 drilled three sites across Brazos-Trinity Basin IV, at the terminal end of a system of four salt-withdrawal intra-slope basins offshore Texas. A 175 m thick succession of sand-rich turbidite fans, mass-transport deposits and hemipelagic sediments was deposited within the last ~120 ka in Basin IV, as recorded at Site U1320. Pre-fan deposits dating back to MIS 6 form a conformable succession of laminated and bioturbated clays, deposited from distal turbidity currents and/or river plumes. The pre-fan succession is capped by a hemipelagic clay interpreted to represent the high stand of sea level during MIS 5e. The basal turbidite deposits in the basin are mud-rich, with the exception of the very first turbidity currents to enter the basin. This initial pulse, possibly derived from failure of older shelf edge deposits, accumulated an ~8 m thick sand-rich interval. A pause in turbidity current influx lasted 30 to 40 kyrs, beginning a few thousand years before ash layer Y8 dated at 84 ka and the Emiliana huxleyi acme. During MIS 3 to MIS 2 sand-rich fans containing 5-25 m thick packets of very fine to lower medium sand beds accumulated up to 130 m of sediments. A 2-3 m thick microfossil-rich clay marks the end of turbidity current influx into the basin during the Holocene. The sedimentary record of Brazos-Trinity Basin IV shows that the accumulation of turbidites in the terminal end of this source to sink depositional system reflects a complex interaction between the availability of material and the initiation of flows at the source near the shelf edge, the interaction of turbidity currents with complex slope topography, and the effects of salt tectonics and flow processes on modifying this topography. The initial results indicate that sealevel changes alone cannot explain the sedimentation patterns observed in the basin.

  16. 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, Stéphane; Andreassian, Vazken

    2013-04-01

    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 km²). 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-Côte d'Azur Region and the French Ministry in charge of Ecology.

  17. Towards catchment classification in data-scarce regions

    SciTech Connect

    Auerbach, Daniel A.; Buchanan, Brian P.; Alexiades, Alex V.; Anderson, Elizabeth P.; Encalada, Andrea C.; Larson, Erin I.; McManamay, Ryan A.; Poe, Gregory L.; Walter, M. Todd; Flecker, Alexander S.

    2016-01-29

    Assessing spatial variation in hydrologic processes can help to inform freshwater management and advance ecological understanding, yet many areas lack sufficient flow records on which to base classifications. Seeking to address this challenge, we apply concepts developed in data-rich settings to public, global data in order to demonstrate a broadly replicable approach to characterizing hydrologic variation. The proposed approach groups the basins associated with reaches in a river network according to key environmental drivers of hydrologic conditions. This initial study examines Colorado (USA), where long-term streamflow records permit comparison to previously distinguished flow regime types, and the Republic of Ecuador, where data limitations preclude such analysis. The flow regime types assigned to gages in Colorado corresponded reasonably well to the classes distinguished from environmental features. The divisions in Ecuador reflected major known biophysical gradients while also providing a higher resolution supplement to an existing depiction of freshwater ecoregions. Although freshwater policy and management decisions occur amidst uncertainty and imperfect knowledge, this classification framework offers a rigorous and transferrable means to distinguish catchments in data-scarce regions. The maps and attributes of the resulting ecohydrologic classes offer a departure point for additional study and data collection programs such as the placement of stations in under-monitored classes, and the divisions may serve as a preliminary template with which to structure conservation efforts such as environmental flow assessments.

  18. Towards catchment classification in data-scarce regions

    DOE PAGES

    Auerbach, Daniel A.; Buchanan, Brian P.; Alexiades, Alex V.; ...

    2016-01-29

    Assessing spatial variation in hydrologic processes can help to inform freshwater management and advance ecological understanding, yet many areas lack sufficient flow records on which to base classifications. Seeking to address this challenge, we apply concepts developed in data-rich settings to public, global data in order to demonstrate a broadly replicable approach to characterizing hydrologic variation. The proposed approach groups the basins associated with reaches in a river network according to key environmental drivers of hydrologic conditions. This initial study examines Colorado (USA), where long-term streamflow records permit comparison to previously distinguished flow regime types, and the Republic of Ecuador,more » where data limitations preclude such analysis. The flow regime types assigned to gages in Colorado corresponded reasonably well to the classes distinguished from environmental features. The divisions in Ecuador reflected major known biophysical gradients while also providing a higher resolution supplement to an existing depiction of freshwater ecoregions. Although freshwater policy and management decisions occur amidst uncertainty and imperfect knowledge, this classification framework offers a rigorous and transferrable means to distinguish catchments in data-scarce regions. The maps and attributes of the resulting ecohydrologic classes offer a departure point for additional study and data collection programs such as the placement of stations in under-monitored classes, and the divisions may serve as a preliminary template with which to structure conservation efforts such as environmental flow assessments.« less

  19. The Effect of Terrain Aspect on Interannual Variability of Hydrologic Response in Mountainous Catchments in New Mexico

    NASA Astrophysics Data System (ADS)

    Zapata, X.; Troch, P. A.; McIntosh, J. C.; Broxton, P. D.; Brooks, P. D.

    2012-12-01

    The aspect of the land surface in mid and high latitudes control hydrological response through differences in energy fluxes, prevailing winds, snow processes, evaporation and transpiration. In the Valles Caldera National Preserve (VCNP) in northern New Mexico, recent research has shown that north facing terrains accumulate thicker snow packs, the snow cover duration is longer, the soil moisture content is higher and hillslopes have longer water transit times. These findings suggest that catchments with a predominant north facing aspect are expected to have more water available and consequently a different hydrological response than catchments characterized by a different land orientation. This poster presents four years (2008-2011) of hydrological data in the VCNP and shows the hydrological response to interannual climate variability in mountainous catchments draining along different aspects. This investigation focuses on three perennial catchments draining Redondo Peak (3435m): La Jara (LJ; 3.67 km2), History Grove (HG; 2.42 km2) and Upper Jaramillo (UJ; 3.06 km2). The three catchments range in elevation between 2680 m and 3429 m. They share similar topographic characteristics, climate, vegetation and a complex geology. The most predominant north facing catchment is UJ; HG and LJ have both a predominant east facing aspect. This study is based on empirical observations of basin response and it has been carried out by way of monitoring physical amount, intensity and timing of water entering and leaving the catchments using the available meteorological data in the region and the instrumented network installed by the Jemez River Basin and Santa Catalina Mountains Critical Zone Observatory (http://www.czo.arizona.edu/). The climate in the region is semi-arid, continental and highly variable. For the water years (WY) 2008 and 2011 annual precipitation was 86% and 71% below the mean (P=711.5mm), and during WY 2009 and 2010, annual precipitation was 4% and 1% above the

  20. 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

  1. 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)

  2. Preliminary thermal-maturity map of the Cameo and Fairfield or equivalent coal zone in the Piceance Creek Basin, Colorado

    USGS Publications Warehouse

    Nuccio, Vito F.; Johnson, Ronald C.

    1983-01-01

    This map was prepared in cooperation with the U.S. Department of Energy's Western Gas Sands Project and was constructed to show the thermal maturity of the Upper Cretaceous Mesaverde Formation (or Group) in the Piceance Creek Basin. The ability of a source rock to generate oil and gas is directly related to its kerogen content and thermal maturity; hence, thermal maturity is commonly used as an exploration tool. This publication consists of two parts: a coal rank map for the basinwide Cameo and Fairfield or equivalent coal zone and three cross sections showing the variation in a coal rank for the entire Mesaverde. Structure contours on the map show the top of the Rollins Sandstone Member of the Mesaverde Formation and its equivalent the Trout Creek Sandstone Member of the Iles Formation of the Mesaverde Group, which immediately underlie the Cameo and Fairfield zone. The structure contours show the fairly strong correlation between structure and coal rank in the basin, suggesting that maximum overburden was the key factor in determining the coal ranks. Even in the southern part of the basin where extensive plutonism occurred during the Oligocene, coal ranks still generally follow structure; indicating that the plutons had little affect on the coals. On the cross sections both the top of the Rollins and Trout Creek, and the top of the Mesaverde Formation/Group are shown. A complete analysis of the entire Mesaverde in the basin would require more information than is presently available.

  3. 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...

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. Elemental composition in sediments and water in the Trancão river basin. A preliminary study

    NASA Astrophysics Data System (ADS)

    Araújo, F.; Pinheiro, T.; Alves, L. C.; Valério, P.; Gaspar, F.; Alves, J.

    1998-03-01

    The Trancão river basin, located in the Lisbon area shows preoccupying pollution levels, that constitute a threat to public health and the ecological system. This work reports on the results obtained in the analysis of surface sediments (EDXRF) and water (PIXE) collected in the wet and dry season during 1996. In general, bulk sediments and water show high concentration levels for some heavy metals like Cr, Cu, Zn and Pb. The elemental contents variation of samples collected at the different sites of the river basin were large, owing apparently to pollution sources, seasonal variabilities and grain size distribution (sediments). In the dry season, effluents (industrial and domestic) showed a stronger influence on the sediment composition. High levels of As and Br were found in the water that can be attributed to extended sources like sewage sludge and fertilizers. In some locations, the metals, Ca and organic matter enrichment could be associated with a paper mill and metal processing industry (high levels of Cr). At the estuary, the decrease of metal content determined in the sampled water indicates the flocculation of dissolved organic and inorganic materials. However, no effects were found for the surface sediment metal content, probably due to a dilution with materials from the Tagus inner estuary (the largest in Portugal).

  12. Preliminary report on investigation of salt springs and seeps in a portion of the Permian Basin in Texas

    USGS Publications Warehouse

    Stevens, P.R.; Hardt, W.F.

    1965-01-01

    The Permian Basin (fig. 1) comprises a large area in the southern midcontinent region and includes major portions of Texas, New Mexico, Oklahoma, and Kansas. Within this basin brine springs and seeps discharge more than 20,000 tons per day of sodium chloride (common table salt). This brine contaminates many streams greatly impairing the utility of their waters. The water in some streams is of such poor quality it cannot be used for municipal and industrial purposes and for irrigation. Nor is the problem limited to the Permian Basin. The contaminated streams leaving the Permian Basin bring salty water to downstream areas of Arkansas and Louisiana, as well as to other parts of Texas, New Mexico, Oklahoma, and Kansas. In no comparable area of the interior United States are natural sources of salt water so widespread or deleterious to the fresh water supply of so large a segment of the nation's population and industry. The Brazos River traverses the eastern part of the Permian Basin, and is potentially one of the principal sources of water in Texas. It carries an average daily load of 1,650 tons of sodium chloride (common table salt) into Possum Kingdom Reservoir, about 110 miles west of Dallas. More than 85 percent of this salt is contributed by the Salt Fork Brazos River, and more than one-half originates from Springs and seeps in Croton and Salt Croton Creeks, tributaries to the Salt Fork Brazos River. The undesirably high chloride content of the water impounded in Possum Kingdom Reservoir limits the utility of this water, although it is used for irrigation and by some industries. Understanding of the origin and hydrology of the natural brine is fundamental to consideration of engineering measures to control the flow of salt water to streams, or to general plans to alleviate the situation in any way that includes altering the brine-discharge system. Previous investigations of natural brine features have been directed toward describing the local details of

  13. Mapping storm velocity over catchments: Distribution and scale dependence for flash flood-inducing storms.

    NASA Astrophysics Data System (ADS)

    Nikolopoulos, E. I.; Zoccatelli, D.; Anagnostou, E. N.

    2012-04-01

    The concept of catchment-scale storm velocity permits examination of storm motion and velocity from the perspective of a distance metric imposed by the drainage network structure of a catchment. This paper aims to examine the distribution and scale-dependency of catchment scale storm velocity values for major flash flood-inducing storms. Eight extreme flash flood-inducing storms occurred in Europe in the period 1999 to 2008 are examined. Analyses are carried out for a set of basins that range in area from 7 to 982 km2. It is shown that the distribution of catchment-scale storm velocity depends on basin-averaged rain rate and catchment size. Hourly velocity values corresponding to maximal rain rates during the flood producing period exhibit a non linear dependence on basin scale and may attain values as high as 2 m s-1. Integration of velocity over the catchment response time leads to a reduction of maximal velocities. Response-time integrated maximal storm velocity shows a peak for catchment scales in the range of 20-100 km2, with values up to 1 m s-1.

  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

  15. Influence of Rainfall Data Resolution and Catchment Subdivision on Runoff Modelling

    NASA Astrophysics Data System (ADS)

    Puttaraksa Mapiam, Punpim; Chauysuk, Suttiched

    2016-04-01

    Precipitation and catchment characteristics are significant factors for runoff modelling. This study demonstrates the relative benefits offered by the application of alternate rainfall products to several scales of catchment subdivision for simulation of the runoff hydrograph in the upper Ping river basin, northern Thailand. Two point locations at the runoff stations in the upper Ping river basin were selected for model calibration over the period of 2004-2005. Rain gauge and radar rainfall products were specified as inputs to the semi-distributed hydrological URBS model at each runoff station with five catchment subdivision schemes for runoff simulation. Point rainfall from the sparse rain gauge network and estimated radar rainfall at each radar pixel were spatially averaged over each sub-catchment using Thiessen polygons and arithmetic averaging approaches, respectively. Results for using high resolution of radar rainfall input appear that the accuracy of runoff estimates is affected appreciably by a number of sub-catchments, and the accuracy of runoff estimates tends to obviously increase with an increase of the number of sub-catchments. On the other hand, there is no significant improvement with an increasing number of sub-catchments while the coarse resolution of rain gauge rainfall input is used. The comparison on runoff accuracy among different scenarios indicates that the use of radar rainfall together with the largest number of sub-catchments gives the highest accuracy of runoff estimates.

  16. 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 Météorologie 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

  17. Regional magnetic and gravity features of the Gibson Dome area and surrounding region, Paradox Basin, Utah : a preliminary report

    USGS Publications Warehouse

    Hildenbrand, T.G.; Kucks, R.P.

    1983-01-01

    Analyses of regional gravity and magnetic anomaly maps have been carried out to assist in the evaluation of the Gibson Dome area as a possible repository site for high-level radioactive waste. Derivative, wavelength-filtered, and trend maps were compiled to aid in properly locating major geophysical trends corresponding to faults, folds, and lithologic boundaries. The anomaly maps indicate that Paradox Basin is characterized by a heterogeneous Precambrian basement, essentially a metamorphic complex of gneisses and schist intruded by granitic rocks and mafic to ultramafic bodies. Interpreted Precambrian structures trend predominantly northwest and northeast although east-west trending features are evident. Prominent gravity lows define the salt anticlines. Structural and lithologic trends in the Gibson Dome area are closely examined. Of greatest interest is a series of circular magnetic highs trending west-northwest into the Gibson Dome area. Further study of the exact definition and geologic significance of this series of anomalies is warranted.

  18. A preliminary study of the calcite beef found in the Cretaceous Jinju Formation, Gyeongsang Basin, South Korea

    NASA Astrophysics Data System (ADS)

    Ha, S.; Chae, Y. U.; Son, M.; Jeong, G. Y.; Paik, I. S.; Lim, H. S.

    2015-12-01

    The term "beef" refers to fibrous minerals in bedding-parallel veins, where the fibers are approximately perpendicular to the vein margins (Cobbold et al., 2013). It mostly appears within organic-rich black shale layers in sedimentary basin. Although the veins can consist of white gangue minerals, such as calcite, gypsum, or quartz, the commonest mineral in the fibers is calcite. According to the worldwide localities of calcite beef compiled by Cobbold et al (2012), they concentrated in some areas, especially around the Atlantic Ocean. However, they have been rarely reported in the western Pacific margin, except Australia and New Zealand. Recently, calcite beefs have been found in the Cretaceous Jinju Formation, Gyeongsang Basin, Korea. As far as we know, this is the first report of calcite beef in Korea. The lacustrine Jinju Formation is about 1,200 m thick, and made up mainly of lacustrine dark grey to black mudstones. In the study area, calcite beefs were commonly found in the organic-rich black shale layers. The vein thickness is anywhere between a few millimeters to maximum 3 centimeters, and their length ranges from a few centimeters to several tens of meters. The interval between successive veins is from a few centimeters to about 1 meter. Most of them occur parallel to the bedding planes, although some of them are developed along fault planes or within deformed layers. In case of relatively thick beefs, the center of veins often shows a dark grey to black central median line, defined by fine-grained calcite grains, fluid inclusion lines, or wall rock particles. Based on the orientation of fibrous calcite, they can be divided into two types: straight and sigmoidal types. The fibrous calcites are thought to have been symmetrically grown from the median lines to top and bottom of wall rock. The formation mechanism of horizontal fractures, and the formation temperature of beefs in the study area remain as a matter to be studied further.

  19. Creating a catchment perspective for river restoration

    NASA Astrophysics Data System (ADS)

    Benda, L.; Miller, D.; Barquín, 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.

  20. 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

  1. Noble Gas geochemistry of the newly discovered hydrothermal fields in the Gulf of California: preliminary He-isotope ratios from the Alarcon Rise and Pescadero basin vent sites

    NASA Astrophysics Data System (ADS)

    Spelz, R. M.; Lupton, J. E.; Evans, L. J.; Zierenberg, R. A.; Clague, D. A.; Neumann, F.; Paduan, J. B.

    2015-12-01

    Numerous submarine deep-sea hydrothermal vents related to volcanic activity of the East Pacific Rise (EPR) are situated along the Pacific margins of Mexico. Until recently, active hydrothermal venting was unknown between the Guaymas Basin and 21°N on the EPR. MBARI's recent oceanographic surveys have added 7 new active vent sites. In this study, we aimed to sample the high-temperature hydrothermal fluids emanating from two distinct vent sites, named Meyibo and Auka, located in the Alarcon Rise and Pescadero Basin, respectively. Mantle-derived He have long been identified in hydrothermal fluid releases. The presence of He in aqueous fluids with 3He/4He ratios greater than in-situ production values (~0.05 RA, where RA = air He or 1.4 x 10-6) indicates the presence of mantle-derived melts. Preliminary analyses of He-isotope ratios derived from the newly discovered Meyibo and Auka hydrothermal fields show high 3He/4He ratios (~8RA), typical of MORB's. Auka vent field, characterized by chimneys composed of light carbonate minerals and oil-like hydrocarbons, and temperatures between 250-290oC, show average values of ~7.87RA. In contrast, the black-smokers at the Meyibo field, composed of dark sulfide minerals and temperatures over 350oC, yielded a higher He ratio of ~8.24RA. Recently, it has become clear that regional maximum mantle He values correlate with the velocity structure in the mantle, therefore, He has the potential to map regions of the underlying mantle that are undergoing partial melting. Seismic records could then be compared with the geochemical He ratio signal and supply information regarding tectonics and other processes involved in the generation of these gases. The data presented here will be completing a totally new inventory of He results from hydrothermal vents in the EPR and fault-termination basins distributed along the P-NA plate boundary in the Gulf of California. The results will be further coupled with the analysis of other geochemical

  2. 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.

  3. 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.

  4. 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.

  5. Study of rock-water-nuclear waste interactions in the Pasco Basin, Washington: Part II. Preliminary equilibrium-step simulations of basalt diagenesis

    SciTech Connect

    Benson, L.V.; Carnahan, C.L.; Che, M.

    1980-08-01

    Interactions between a large number of complex chemical and physical processes have resulted in significant changes in the Pasco Basin hydrochemical system since emplacement of the first basalt flow. In order to perform preliminary simulations of the chemical evolution of this system, certain simplifying assumptions and procedures were adopted and a computer model which operates on the principal of local equilibrium was used for the mass transfer calculations. Significant uncertainties exist in both the thermodynamic and reaction rate data which were input to the computer model. In addition, the compositional characteristics of the evolving hydrochemical system remain largely unknown, especially as a function of distance along the flow path. Given these uncertainties, it remains difficult to assess the applicability of the equilibrium-step approach even though reasonable matches between observed and simulated hydrochemical data were obtained. Given the uncertainties mentioned, the predictive abilities of EQ6 are difficult, if not impossible to evaluate; our simulations produced, at best, only qualitative agreement with observed product mineral assemblages and sequences, and fluid compositions.

  6. 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

  7. 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.

  8. 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.

  9. Temporal and Spatial Variation of Surface Water Stable Isotopes in the Marys River Basin, Oregon

    NASA Astrophysics Data System (ADS)

    Nickolas, L. B.; Segura, C.; Brooks, J. R.

    2015-12-01

    Understanding the temporal and spatial variability of water sources within a basin is vital to our ability to manage the impacts of climate variability and land cover change. Water stable isotopes can be used as a tool to determine geographic and seasonal sources of water at the basin scale. Previous studies in the Coastal Range of Oregon reported that the variation in the isotopic signatures of surface water does not conform to the commonly observed "rainout effect", which exhibits a trend of increasing isotopic depletion with rising elevation. The primary purpose of this research is to investigate the mechanisms governing seasonal and spatial variations in the isotopic signature of surface waters within the Marys River Basin, located in the Oregon Coastal Range. We hypothesize that catchment orientation, drainage area, geology, and topography act as controlling factors on groundwater flow, storage, and atmospheric moisture cycling, which explain variations in source water contribution. Surface water and precipitation samples were collected every 2-3 weeks for isotopic analysis of δ18O and δ2H for one year. Preliminary results indicate a significant difference (p<0.001) in isotopic signature between watersheds underlain by basalt and sandstone. The degree of separation is the most distinct during the summer when low flows likely reflect deeper groundwater sources, whereas isotopic signatures during the rainy season (fall & winter) show a greater degree of similarity between the two lithologies. These findings indicate that the more permeable sandstone formations may be hydrologically connected to enriched water sources on the windward side of the Coastal Range that sustain baseflow within catchments on the leeward side, while streams draining basalt catchments are fed by a more depleted source of water (e.g. precipitation originating within the Marys River Basin).

  10. Moments of catchment storm area

    NASA Technical Reports Server (NTRS)

    Eagleson, P. S.; Wang, Q.

    1985-01-01

    The portion of a catchment covered by a stationary rainstorm is modeled by the common area of two overlapping circles. Given that rain occurs within the catchment and conditioned by fixed storm and catchment sizes, the first two moments of the distribution of the common area are derived from purely geometrical considerations. The variance of the wetted fraction is shown to peak when the catchment size is equal to the size of the predominant storm. The conditioning on storm size is removed by assuming a probability distribution based upon the observed fractal behavior of cloud and rainstorm areas.

  11. 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.

  12. Recognising the Anthropocene at a Regional-Catchment Scale

    NASA Astrophysics Data System (ADS)

    Brown, Tony

    2014-05-01

    Recent reviews concerning the recognition of the Anthropocene in geomorphology have focussed on small to medium-sized catchments and have aggregated these studies to derive regional syntheses. However, the erosional and sedimentary responses to human activities vary both in nature and scale within regional-scale or medium to large catchments. Geomorphological responses also vary in their connectivity and this is, and will be, reflected in the residence time of Anthropogenic units and earth surface properties. This paper will explore the variation of anthropogenic responses in a medium-sized sedimentary basin (the Somerset Levels basin) which drains into the estuary of the River Severn in the UK. It will be shown that different human activities at different dates, and driven by very different socio-economic factors, interact and change geomorphic connectivity producing a palimpsest of anthropogenic geomorphic responses with highly variable surface expression and geochemical signatures.

  13. Hydrological Catchment Similarity Assessment in Geum River Catchments, Korea

    NASA Astrophysics Data System (ADS)

    Ko, Ara; Park, Kisoon; Lee, Hyosang

    2013-04-01

    Similarity measure of catchments is essential for regionalization studies, which provide in depth analysis in hydrological response and flood estimations at ungauged catchments. However, this similarity measure is often biased to the selected catchments and is notclearly explained in hydrological sense. This study applied a type of hydrological similarity distance measure-Flood Estimation Handbook to 25 Geum river catchments, Korea. Three Catchment Characteristics, Area (A)-Annual precipitation (SAAR)-SCS Curve Number (CN), are used in Euclidian distance measures. Furthermore, six index of Flow Duration Curve (ILow:Q275/Q185, IDrought:Q355/Q185, IFlood:Qmax/Q185, IAbundant:Q95/Q185, IFloodDuration:Q10/Q355 and IRiverRegime:Qmax/Qmin) are applied to clustering analysis of SPSS. The catchments' grouping of hydrological similarity measures suggests three groups: H1 (Cheongseong, Gidae, Bukil, Oksan, Seockhwa, Habgang and Sangyeogyo), H2 (Cheongju, Guryong, Ugon, Boksu, Useong and Seokdong) and H3 (Muju, Yangganggyo and YongdamDam). The four catchments (Cheoncheon, Donghyang, DaecheongDam and Indong) are not grouped in this study. The clustering analysis of FDC provides four Groups; CFDC1 (Muju, YongdamDam, Yangganggyo, DaecheongDam, Cheongseong, Gidae, Seokhwa, Bukil, Habgang, Cheongju, Oksan, Yuseong and Guryong), CFDC2 (Cheoncheon, Donghyang, Boksu, Indong, Nonsan, Seokdong, Ugon, Simcheon, Useong and Sangyeogyo), CFDC3 (Songcheon) and CFDC4 (Tanbu). The six catchments (out of seven) of H1 are grouped in CFDC1, while Sangyeogyo is grouped in CFDC2. The four catchments (out of six) of H2 are also grouped in CFDC2, while Cheongju and Guryong are grouped in CFDC1. The catchments of H3 are categorized in CFDC1. The authors examine the results (H1, H2 and H3) of similarity measure based on catchment physical descriptors with results (CFDC1 and CFDC2) of clustering based on catchment hydrological response. The results of hydrological similarity measures are supported by

  14. 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.

  15. Holocene Paleoenvironment of the North-central Great Basin: Preliminary Results from Favre Lake, Northern Ruby Mountains, Nevada

    NASA Astrophysics Data System (ADS)

    Starratt, S.; Wahl, D.; Wan, E.; Anderson, L.; Wanket, J.; Olson, H.; Lloyd-Davies, T.; Kusler, J.

    2009-12-01

    Little is known about Holocene climate variability in north-central Nevada. This study aims to assess changes in watershed vegetation, fire history, lake levels and limnological conditions in order to understand secular to millennial-scale changes in regional climate. Favre Lake (2,899 m a.s.l.; 12 m deep; 7.7 hectares) is a flow-through lake in the northern Ruby Mountains. The primary sources of influent, both of which appear to be intermittent, are Castle Lake (2,989 m a.s.l.) and Liberty Lake (3,077 m a.s.l.). The bedrock of the three lake basins is early Paleozoic marble and Mesozoic granite and metamorphic rocks. Bathymetric maps and temperature, pH, salinity, and conductivity profiles have been generated for Favre Lake. Surface samples and a series of cores were also collected using a modified Livingstone piston corer. The presence of the Mazama ash in the basal sediment (~4 m below the sediment/water interface) indicates the record extends to ~7,700 cal yr B.P. Magnetic susceptibility (MS) and loss-on-ignition data indicate that the sediments in the lowest part of the core contain primary and reworked Mazama ash. About 2,000 years ago CaCO3 increased from 2 to 3% of the inorganic sediment. The upper 25 cm of the core are marked by an increase in MS which may indicate increased erosion due to grazing. Between about 7,700 and 6,000 cal yr B.P. the diatom flora is dominated by a diverse assemblage of benthic species. The remainder of the core is dominated by Fragilaria, suggesting that lake level rose and flooded the shelf that surrounds the depocenter of the lake. This is supported by changes in the abundance of the aquatic fern Isoetes. Pinus and Artemisia dominate the pollen record, followed by subordinate levels of Poaceae, Asteraceae, Amaranthaceae, and Sarcobatus. The late early Holocene (7,700-6,000 cal yr B.P.) is dominated by Pinus which is present in reduced amounts during the middle Holocene (6,000-3,000 cal yr B.P.) and then returns to dominance in

  16. Modeling seasonal export and retention of nutrients in european catchments.

    NASA Astrophysics Data System (ADS)

    de Klein, J.

    2003-04-01

    In the abatement of eutrophication of standing waters management of sources and transport of nutrients in river catchments is crucial. However the transport of nitrogen and phosphorus can vary significantly among (sub) catchments as a result of different physical, chemical and biotic factors. Qualitative and quantitative differences in nutrient pathways within catchments hamper the application of common standards and reliable prediction of the effect of nutrient loads. The EU-project BUFFER is set up to provide a tool which describes the relation between catchment properties and activities resulting in nutrient loads on one hand, and the ecological state of the receiving lakes on the other hand. To support this a new model-concept is developed that describes the transport and retention of nutrients in running waters (De Klein, 2002). The calculation requires minimum input data and generates output on a seasonal basis. The model was so far applied to Dutch catchments. This paper presents the extension and verification of the model, based on data of intensively studied catchments within the BUFFER-project. This implies the method can be applied to a wider range of European catchments. Basic model inputs are total annual loads of nutrients from point and diffuse sources to the surface (head) waters. During transport nutrients are retained in the catchment. Retention coefficients vary over the seasons and are calculated from a) residence time, which can be approximated using rainfall data, size of drainage basin and morphological properties b) temperature. The model outputs retention and export from the catchment on a monthly basis, using a set of straightforward formulas. Coefficients are calibrated with a subset of the measured data in an optimization routine, and subsequently verified. The similarity of measured and calculated values was high (r2 > 0.8; p<0.01). With a rather simple calculation method with few input data it is possible to estimate monthly export

  17. Effect of large rainfall events on runoff and soil losses in two small experimental agricultural catchments in Southern Spain

    NASA Astrophysics Data System (ADS)

    Gómez, J. A.; Taguas, E. V.; Vanwalleghem, T.; Pérez-Alcántara, R.

    2010-05-01

    This communication presents the results and a preliminary discussion of the results of a medium term monitoring of runoff and soil losses in two small agricultural catchments, Conchuela and Puente Genil, of 8.0 and 6.1 ha respectively. Puente Genil has been monitored since 2005 and Conchuela since 2006. The gauging station at both catchments is composed of a measure flume provided of an ultrasonic water depth sensor, a raingauge and an ISCO sampler for taking suspended sediment samplers. The Puente Genil catchment presents average slope of 15%, and is on a soil of loamy sand texture, while La Conchuela presents an average slope of 9% and is on a clay soil. Soil management in both catchments is based on no tillage with mechanical or chemical control of the adventitious vegetation growing in the inter tree space since mid March, to avoid competition for soil water with the olive trees. The years monitored since 2005/06 to 2008/09 were significantly below the average rainfall in the region with a reduced number of intense events. So, annual soil losses for both basins ranged from 4 to less than 0.2 t ha-1 year-1, and average annual runoff coefficients ranging from 8 to less than 3 %. Hydrological year 2009/2010 has presented unusually high rainfalls. By early January cumulative rainfall from September first is above the average annual rainfall, and a large number of highly erosive events have been monitored in both catchments. Provisional results indicate that these periodical episodes of moist years with high intensity events are key in evaluating the erosive and hydrological behaviour of agricultural areas in Southern Spain. For instance, the sediment delivered from La Conchuela trough the monitoring station during 2009/10 has been estimated in 13.9 t ha-1 by January 2nd. The practical implications for monitoring schemes under these conditions, and the need of long term experiments that need to be complemented with model analysis will be discussed trough this

  18. 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).

  19. River nutrient loads and catchment size

    USGS Publications Warehouse

    Smith, S.V.; Swaney, D.P.; Buddemeier, R.W.; Scarsbrook, M.R.; Weatherhead, M.A.; Humborg, Christoph; Eriksson, H.; Hannerz, F.

    2005-01-01

    We have used a total of 496 sample sites to calibrate a simple regression model for calculating dissolved inorganic nutrient fluxes via runoff to the ocean. The regression uses the logarithms of runoff and human population as the independent variables and estimates the logarithms of dissolved inorganic nitrogen and phosphorus loading with R 2 values near 0.8. This predictive capability is about the same as has been derived for total nutrient loading with process-based models requiring more detailed information on independent variables. We conclude that population and runoff are robust proxies for the more detailed application, landscape modification, and in-stream processing estimated by more process-based models. The regression model has then been applied to a demonstration data set of 1353 river catchments draining to the sea from the North American continent south of the Canadian border. The geographic extents of these basins were extracted from a 1-km digital elevation model for North America, and both runoff and population were estimated for each basin. Most of the basins (72% of the total) are smaller than 103 km2, and both runoff and population density are higher and more variable among small basins than among larger ones.While total load to the ocean can probably be adequately estimated from large systems only, analysis of the geographic distribution of nutrient loading requires consideration of the small basins, which can exhibit significant hydrologic and demographic heterogeneity between systems over their range even within the same geographic region. High-resolution regional and local analysis is necessary for environmental assessment and management. ?? Springer 2005.

  20. 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.

  1. Characterising groundwater-dominated lowland catchments: the UK Lowland Catchment Research Programme (LOCAR)

    NASA Astrophysics Data System (ADS)

    Wheater, H. S.; Peach, D.; Binley, A.

    2007-01-01

    This paper reports on a major UK initiative to address deficiencies in understanding the hydro-ecological response of groundwater-dominated lowland catchments. The scope and objectives of this national programme are introduced and focus on one of three sets of research basins - the Pang/Lambourn Chalk catchments, tributaries of the river Thames in southern England. The motivation for the research is the need to support integrated management of river systems that have high ecological value and are subject to pressures that include groundwater abstraction for water supply, diffuse pollution, and land use and climate change. An overview of the research programme is provided together with highlights of some current research findings concerning the hydrological functioning of these catchments. Despite the importance of the Chalk as a major UK aquifer, knowledge of the subsurface movement of water and solutes is poor. Solute transport in the dual porosity unsaturated zone depends on fracture/matrix interactions that are difficult to observe; current experimental and modelling research supports the predominance of matrix flow and suggests that slow migration of a time-history of decades of nutrient loading is occurring. Groundwater flows are complex; catchments vary seasonally and are ill-defined and karst features are locally important. Groundwater flow pathways are being investigated using natural and artificial geochemical tracers based on experimental borehole arrays; stream-aquifer interaction research is using a combination of geophysics, borehole array geochemistry and longitudinal profiles of stream flow and solutes. A complex picture of localised subsurface inflows, linked to geological controls and karst features, and significant longitudinal groundwater flow below the river channel is emerging. Management implications are discussed. Strategies to control surface application of nutrients are expected to have little effect on groundwater quality for several

  2. 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.

  3. Assessment of LULC and climate change on the hydrology of Ashti Catchment, India using VIC model

    NASA Astrophysics Data System (ADS)

    Hengade, Narendra; Eldho, T. I.

    2016-12-01

    The assessment of land use land cover (LULC) and climate change over the hydrology of a catchment has become inevitable and is an essential aspect to understand the water resources-related problems within the catchment. For large catchments, mesoscale models such as variable infiltration capacity (VIC) model are required for appropriate hydrological assessment. In this study, Ashti Catchment (sub-catchment of Godavari Basin in India) is considered as a case study to evaluate the impacts of LULC changes and rainfall trends on the hydrological variables using VIC model. The land cover data and rainfall trends for 40 years (1971-2010) were used as driving input parameters to simulate the hydrological changes over the Ashti Catchment and the results are compared with observed runoff. The good agreement between observed and simulated streamflows emphasises that the VIC model is able to evaluate the hydrological changes within the major catchment, satisfactorily. Further, the study shows that evapotranspiration is predominantly governed by the vegetation classes. Evapotranspiration is higher for the forest cover as compared to the evapotranspiration for shrubland/grassland, as the trees with deeper roots draws the soil moisture from the deeper soil layers. The results show that the spatial extent of change in rainfall trends is small as compared to the total catchment. The hydrological response of the catchment shows that small changes in monsoon rainfall predominantly contribute to runoff, which results in higher changes in runoff as the potential evapotranspiration within the catchments is achieved. The study also emphasises that the hydrological implications of climate change are not very significant on the Ashti Catchment, during the last 40 years (1971-2010).

  4. Preliminary assessment of channel stability and bed-material transport in the Tillamook Bay tributaries and Nehalem River basin, northwestern Oregon

    USGS Publications Warehouse

    Jones, Krista L.; Keith, Mackenzie K.; O'Connor, Jim E.; Mangano, Joseph F.; Wallick, J. Rose

    2012-01-01

    This report summarizes a preliminary study of bed-material transport, vertical and lateral channel changes, and existing datasets for the Tillamook (drainage area 156 square kilometers [km2]), Trask (451 km2), Wilson (500 km2), Kilchis (169 km2), Miami (94 km2), and Nehalem (2,207 km2) Rivers along the northwestern Oregon coast. This study, conducted in coopera-tion with the U.S. Army Corps of Engineers and Oregon Department of State Lands to inform permitting decisions regarding instream gravel mining, revealed that: * Study areas along the six rivers can be divided into reaches based on tidal influence and topography. The fluvial (nontidal or dominated by riverine processes) reaches vary in length (2.4-9.3 kilometer [km]), gradient (0.0011-0.0075 meter of elevation change per meter of channel length [m/m]), and bed-material composition (a mixture of alluvium and intermittent bedrock outcrops to predominately alluvium). In fluvial reaches, unit bar area (square meter of bar area per meter of channel length [m2/m]) as mapped from 2009 photographs ranged from 7.1 m2/m on the Tillamook River to 27.9 m2/m on the Miami River. * In tidal reaches, all six rivers flow over alluvial deposits, but have varying gradients (0.0001-0.0013 m/m) and lengths affected by tide (1.3-24.6 km). The Miami River has the steepest and shortest tidal reach and the Nehalem River has the flattest and longest tidal reach. Bars in the tidal reaches are generally composed of sand and mud. Unit bar area was greatest in the Tidal Nehalem Reach, where extensive mud flats flank the lower channel. * Background factors such as valley and channel confinement, basin geology, channel slope, and tidal extent control the spatial variation in the accumulation and texture of bed material. Presently, the Upper Fluvial Wilson and Miami Reaches and Fluvial Nehalem Reach have the greatest abundance of gravel bars, likely owing to local bed-material sources in combination with decreasing channel gradient and

  5. Linking Soil Moisture, Micro-climate, and Transpiration in a Headwater Catchment

    NASA Astrophysics Data System (ADS)

    Barnard, H. R.; Brooks, J.; Kayler, Z.; Sulzman, E. W.; Phillips, C. L.; McDonnell, J. J.; Bond, B. J.

    2007-12-01

    Evapotranspiration is a major determinant of streamflow in forested basins. However, the role topography plays in forest water relations is poorly understood. To date, many hydrological models use only a single value for transpiration across a catchment. Quantifying the variation in forest water use with regards to slope position is central to understanding controls on water quantity and quality in hydro-ecological models and is critical to predicting the hydrologic impacts of various forestry operations. We measured transpiration, soil moisture, and foliar pre-dawn water potential in 4 plots across a ridge to ridge transect throughout the summers of 2005 and 2006 in a headwater catchment in western Oregon. Additionally, we measured deuterium and 18O of xylem water and soil water to track changes in the depth of transpiration source water throughout the summers. From May through October 2006, daily average transpiration in upslope plots was approximately 40% greater than that of valley bottom plots (1.0 mm day-1 vs. 0.6 mm day-1, respectively). Minimum pre-dawn water potential values ranged from -0.8 to -1.3 MPA in late August with north-facing plots having the lowest values. Stable isotope data indicates that transpiration rates remained higher longer in the growing season in plots where trees were able to access water deeper in the soil profile. Preliminary data suggest that topographic gradients influencing soil depth, soil moisture retention, and micro-climate result in large variation in forest water use over very small distances.

  6. 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.

  7. 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.

  8. Runoff predictions in ungauged catchments in southeast Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Li, Fapeng; Zhang, Yongqiang; Xu, Zongxue; Liu, Changming; Zhou, Yanchun; Liu, Wenfeng

    2014-04-01

    The Tibetan Plateau (TP) plays a key role on both hydrology and climate for southern and eastern Asia. Improving runoff predictions in ungauged catchments in the TP is critical for surface water hydrology and water resources management in this region. However, a detailed runoff prediction study in this region has not been reported yet. To fill the gap, this study evaluates two regionalization approaches, spatial proximity and physical similarity, for predicting runoff using two rainfall-runoff models (SIMHYD and GR4J). These models are driven by meteorological inputs from eight large non-nested catchments (4000-50,000 km2) in the Yarlung Tsangpo River basin located in southeast TP. For each catchment, the two models are calibrated using data from the first two-thirds of the observation period and validated over the remaining period. The calibrated and validated Nash-Sutcliffe Efficiency of monthly runoff (NSE) varies from 0.73 to 0.93 for the SIMHYD model, and are similar to or slightly better than those obtained for the GR4J model. The incorporation of snowfall-snowmelt processes into the rainfall-runoff models does not noticeably improve the runoff predictions in the study area. The main reason is that monthly runoff is dominated by summer precipitation and snowfall in winter accounts for a small percentage (less than 14%). The results from both models show that the spatial proximity approach marginally outperforms the physical similarity approach and both approaches are better than random selection of a donor catchment. This is consistent with recent regionalization studies carried out in Europe and Australia. The study suggests that conceptual rainfall-runoff models are powerful and simple tools for monthly runoff predictions in large catchments in southeast TP, and incorporation of more catchments into regionalization can further improve prediction skills.

  9. 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.

  10. Evaluating stream water quality through land use analysis in two grassland catchments: impact of wetlands on stream nitrogen concentration.

    PubMed

    Hayakawa, A; Shimizu, M; Woli, K P; Kuramochi, K; Hatano, R

    2006-01-01

    We evaluated the impacts of natural wetlands and various land uses on stream nitrogen concentration in two grassland-dominated catchments in eastern Hokkaido, Japan. Analyzing land use types in drainage basins, measuring denitrification potential of its soil, and water sampling in all seasons of 2003 were performed. Results showed a highly significant positive correlation between the concentration of stream NO3-N and the proportion of upland area in drainage basins in both catchments. The regression slope, which we assumed to reflect the impact on water quality, was 24% lower for the Akkeshi catchment (0.012 +/- 0.001) than for the Shibetsu catchment (0.016 +/- 0.001). In the Akkeshi catchment, there was a significant negative correlation between the proportion of wetlands in the drainage basins and stream NO3-N concentration. Stream dissolved organic nitrogen (DON) and carbon (DOC) concentrations were significantly higher in the Akkeshi catchment. Upland and urban land uses were strongly linked to increases in in-stream N concentrations in both catchments, whereas wetlands and forests tended to mitigate water quality degradation. The denitrification potential of the soils was highest in wetlands, medium in riparian forests, and lowest in grasslands; and was significant in wetlands and riparian forests in the Akkeshi catchment. The solubility of soil organic carbon (SOC) and soil moisture tended to determine the denitrification potential. These results indicate that the water environment within the catchments, which influences denitrification potential and soil organic matter content, could have caused the difference in stream water quality between the two catchments.

  11. 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

  12. 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

  13. Preliminary correlation of palynological assemblages from Oman with the Granulatisporites confluens Oppel Zone of the grant formation (lower Permian), Canning Basin, Western Australia

    NASA Astrophysics Data System (ADS)

    Stephenson, Michael H.

    1998-05-01

    The presence of Granulatisporites confluens Archangelsky and Gamerro indicates an Asselian-Tastubian (lowermost Permian) age for glaciogene sediments in the Amal-6 borehole, Oman. This suggests that the Al Khlata Formation is in part coeval with glaciogene sediments of the Canning Basin, Western Australia, and sediments of the Chacoparana Basin, Argentina.

  14. Source and transport factors influencing storm phosphorus losses in agricultural catchments

    NASA Astrophysics Data System (ADS)

    Shore, Mairead; Jordan, Phil; Mellander, Per-Erik; kelly-quinn, Mary; Wall, David; Murphy, Paul; Melland, Alice

    2014-05-01

    The relative risk of diffuse phosphorus (P) loss from agricultural land was assessed in a well-drained arable catchment and a poorly-drained grassland catchment and in two nested basins within each catchment. This research investigated the relative control of hydrology and soil P on P losses between basins. Quick flow (QF) P losses (defined here as both concentrations and loads), monitored in stream flow during four storm events, were compared with a dynamic metric of transport risk (QF magnitude) and a static metric of critical source area (CSA) risk (extent of highly-connected poorly-drained soils with excess plant-available soil P). The potential for static transport metrics of soil connectivity and soil drainage class, to predict relative QF magnitudes and P losses between basins was also investigated. In basins with similar CSA risk but with contrasting QF magnitudes, mean TRP (total molybdate-reactive P) losses were consistently higher in the basins which had the highest QF magnitudes. This suggests that basin hydrology, rather than hydrology of high-P soils only, determined relative TRP losses between hydrologically contrasting basins. Furthermore, static transport metrics of soil connectivity and soil drainage class reliably discerned relative QF magnitudes and TRP losses between these basins. However, for two of the storm events (both occurring during the hydrologically active season), PP (particulate P) concentrations were frequently higher in basins which had the lowest QF magnitudes and may be attributed to a higher proportion of bare soil in these basins at these times as a result of their predominantly arable nature. In basins with similar hydrology, relative TRP and PP losses did not reflect trends in CSA risk or QF magnitude. The dynamics of TRP and PP losses and QF magnitude between these basins varied across storms, thus could not be predicted using static metrics. Where differences in hydrological dynamics were large, storm TRP losses were well

  15. Old groundwater influence on stream hydrochemistry and catchment response times in a small Sierra Nevada catchment: Sagehen Creek, California

    USGS Publications Warehouse

    Rademacher, L.K.; Clark, J.F.; Clow, D.W.; Hudson, G.B.

    2005-01-01

    [1] The relationship between the chemical and isotopic composition of groundwater and residence times was used to understand the temporal variability in stream hydrochemistry in Sagehen basin, California. On the basis of the relationship between groundwater age and [Ca2+], the mean residence time of groundwater feeding Sagehen Creek during base flow is approximately 28 years. [Cl-]:[Ca2+] ratios in Sagehen Creek can be used to distinguish between two important processes: changes in the apparent age of groundwater discharging into the creek and dilution with snowmelt. The mean residence time of groundwater discharging into the creek is approximately 15 years during snowmelt periods. The results from this study have implications for hydrograph separation studies as groundwater is not a single, well-mixed chemical component but rather is a variable parameter that predictably depends on groundwater residence time. Most current models of catchment hydrochemistry do not account for chemical and isotopic variability found within the groundwater reservoir. In addition, this study provides valuable insight into the long-term hydrochemical response of a catchment to perturbations as catchment-flushing times are related to the mean residence time of water in a basin. Copyright 2005 by the American Geophysical Union.

  16. Towards a generalized catchment flood processes simulation system with distributed hydrological model

    NASA Astrophysics Data System (ADS)

    Chen, Y.

    2015-12-01

    High resolution distributed hydrological model is regarded as to have the potential to finely simulate the catchment hydrological processes, but challenges still exist. This paper, presented a generalized catchment flood processes simulation system with Liuxihe Model, a physically-based distributed hydrological model proposed mainly for catchment flood forecasting, which is a process-based hydrological model. In this system, several cutting edge technologies have been employed, such as the supercomputing technology, PSO algorithm for parameter optimization, cloud computation, GIS and software engineering, and it is deployed on a high performance computer with free public accesses. The model structure setting up data used in this system is the open access database, so it could be used for catchments world widely. With the application of parallel computation algorithm, the model spatial resolution could be as fine as up to 100 m grid, while maintaining high computation efficiency, and could be used in large scale catchments. With the utilization of parameter optimization method, the model performance cold be improved largely. The flood events of several catchments in southern China with different drainage sizes have been simulated by this system, and the results show that this system has strong capability in simulating catchment flood events even in large river basins.

  17. 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.

  18. 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

  19. 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 Bødalen 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 Bødalen 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

  20. 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 δ18O and 3H) and stream flow. Preliminary groundwater isotope data reflect depleted δ18O 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

  1. Towards Estimating the Nutrient Balance of the Hydrologic Open Air Laboratory (HOAL) Catchment, Lower Austria

    NASA Astrophysics Data System (ADS)

    Exner-Kittridge, Michael; Zessner, Matthias; Broer, Martine; Eder, Alexander; Strauss, Peter; Blöschl, Günter

    2010-05-01

    focused on the identification of the magnitude of the contributing sources of nutrients within the catchment. Water quality data from the catchment outlet have been assessed and preliminary estimates of the spatial and temporal nature of the nutrient pathways have been determined. With estimates of source contribution, we have devised methodologies at every scale within the catchment to accurately estimate the nutrient fluxes and techniques to upscale from the field scale to the catchment scale.

  2. Sediment sources in the Lake Tahoe Basin, California-Nevada; preliminary results of a four-year study, August 1983-September 1987

    USGS Publications Warehouse

    Hill, B.R.; Hill, J.R.; Nolan, K.M.

    1988-01-01

    Data were collected during a 4-yr study of sediment sources in four drainage basins tributary to Lake Tahoe, California-Nevada. The study areas include the Blackwood, General, Edgewood, and Logan House Creek basins. Data include changes in bank and bed positions at channel cross sections; results of stream-channel mapping; analyses of bank and bed material samples; tabulations of bed material point counts; measured rates of hillslope erosion; dimensions of gullies; suspended-sediment data collected during synoptic snowmelt sampling; and physiographic data for the four study basins. (USGS)

  3. The role of topography on catchment-scale water residence time

    USGS Publications Warehouse

    McGuire, K.J.; McDonnell, Jeffery J.; Weiler, M.; Kendall, C.; McGlynn, B.L.; Welker, J.M.; Seibert, J.

    2005-01-01

    The age, or residence time, of water is a fundamental descriptor of catchment hydrology, revealing information about the storage, flow pathways, and source of water in a single integrated measure. While there has been tremendous recent interest in residence time estimation to characterize watersheds, there are relatively few studies that have quantified residence time at the watershed scale, and fewer still that have extended those results beyond single catchments to larger landscape scales. We examined-topographic controls on residence time for seven catchments (0.085-62.4 km2) that represent diverse geologic and geomorphic conditions in the western Cascade Mountains of Oregon. Our primary objective was to determine the dominant physical controls on catchment-scale, water residence time and specifically test the hypothesis that residence time is related to the size of the basin. Residence times were estimated by simple convolution models that described the transfer of precipitation isotopic composition to the stream network. We found that base flow mean residence times for exponential distributions ranged from 0.8 to 3.3 years. Mean residence time showed no correlation to basin area (r2 < 0.01) but instead was correlated (r2 =-0:91) to catchment terrain indices representing the flow path distance and flow path gradient to the stream network. These results illustrate that landscape organization (i.e., topography) rather than basin area controls catchment-scale transport. Results from this study may provide a framework for describing scale-invariant transport across climatic and geologic conditions, whereby the internal form and structure of the basin defines the first-order control on base flow residence time. Copyright 2005 by the American Geophysical Union.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. Using isotope, hydrochemical methods and energy-balance modelling to estimate contribution of different components to flow forming process in a high-altitude catchment (Dzhancuat river basin case study)

    NASA Astrophysics Data System (ADS)

    Rets, Ekaterina; Loshakova, Nadezhda; Chizhova, Julia; Kireeva, Maria; Frolova, Natalia; Tokarev, Igor; Budantseva, Nadine; Vasilchuk, Yurij

    2016-04-01

    A multicomponent structure of sources of river runoff formation is characteristic of high-altitude territories: ice and firn melting; seasonal snow melting on glacier covered and non-glacier area of a watershed; liquid precipitation; underground waters. In addition, each of these components can run off the watershed surface in different ways. Use of isotopic, hydrochemical methods and energy balance modelling provides possibility to estimate contribution of different components to river runoff that is an essential to understand the mechanism of flow formation in mountainious areas. A study was carried out for Dzhancuat river basin that was chosen as representative for North Caucasus in course of the International Hydrological Decade. Complex glaciological, hydrological and meteorological observation have been carried in the basin since 1965. In years 2013-2015 the program also included daily collecting of water samples on natural stable isotopes on the Dzhancuat river gauging station, and sampling water nourishment sources (ice, snow, firn, liquid precipitation) within the study area. More then 800 water samples were collected. Application of an energy balance model of snow and ice melt with distributed parameters provided an opportunity to identify Dzhancuat river runoff respond to glaciers melt regime and seasonal redistribution of melt water. The diurnal amplitude of oscillation of the Dzhakuat river runoff in the days without precipitation is formed by melting at almost snow-free areas of the Dzhancuat glacier tongues. Snowmelt water from the non-glacierized part contributes to the formation of the next day runoff. A wave of snow and firn melt in upper zones of glacier flattens considerably during filtration through snow and run-off over the surface and in the body of the glacier. This determines a general significant inertia of the Dzhacuat river runoff. Some part of melt water is stored into natural regulating reservoirs of the watershed that supply the

  10. 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)

  11. Climate-vegetation-soil interactions and long-term hydrologic partitioning: signatures of catchment co-evolution

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    Catchment hydrologic partitioning, regional vegetation composition and soil properties are strongly affected by climate, but the effects of climate-vegetation-soil interactions on river basin water balance are still poorly understood. Here we use a physically-based hydrologic model separately parameterized in 12 US catchments across a climate gradient to decouple the impact of climate and landscape properties to gain insight into the role of climate-vegetation-soil interactions in long-term hydrologic partitioning. The 12 catchment models (with different parameterizations) are subjected to the 12 different climate forcings, resulting in 144 10-yr model simulations. The results are analyzed per catchment (one catchment model subjected to 12 climates) and per climate (one climate filtered by 12 different model parameterization), and compared to water balance predictions based on Budyko's hypothesis (E/P = φ (EP/P); E: evaporation, P: precipitation, EP: potential evaporation). We find significant anti-correlation between average deviations of the evaporation index (E/P) computed per catchment vs. per climate, compared to that predicted by Budyko. Catchments that on average produce more E/P have developed in climates that on average produce less E/P, when compared to Budyko's prediction. Water and energy seasonality could not explain these observations, confirming previous results reported by Potter et al. (2005). Next, we analyze which model (i.e., landscape filter) characteristics explain the catchment's tendency to produce more or less E/P. We find that the time scale that controls perched aquifer storage release explains the observed trend. This time scale combines several geomorphologic and hydraulic soil properties. Catchments with relatively longer aquifer storage release time scales produce significantly more E/P. Vegetation in these catchments have longer access to this additional groundwater source and thus are less prone to water stress. Further analysis

  12. A water and sediment budget for a Mediterranean mountainous catchment (Southern Pyrenees)

    NASA Astrophysics Data System (ADS)

    Tuset, Jordi; Vericat, Damià; Batalla, Ramon J.

    2016-04-01

    Sediment transport in Mediterranean mountainous catchments is highly variable influenced principally by sediment availability, which in turn is controlled by the temporal and spatial variability of rainfall, runoff and land uses. In this paper we present the water and sediment budget of the Ribera Salada, a Mediterranean forest catchment located in the Catalan Pre-Pyrenees (NE Iberian Peninsula). The river drains an area of 224 km2. The data acquisition design is composed by five nested experimental sub-catchments. Each monitoring station registers discharge and suspended sediment transport continuously. Here we present the data obtained between 2012 and 2013, two contrasted hydrological years. These data allows to analyse the contribution of each sub-catchment to the total water and suspended sediment yield of the catchment at multiple temporal scales. Annual water yield in the catchment outlet varied between 15 and 31 hm3 y-1. Maximum peak flow in the outlet of the basin was 60.9 m3 s-1; equivalent to a specific discharge of 0.28 m3 s-1 km2. Results indicate that, hydrologically, the catchment can divided in two areas with contrasted regimes. The upper part of catchment is the wettest zone, where the water yield of each sub-catchment is in directly and positive correlated to its area. In contrast, the bottom of the valley has an ephemeral hydrological regime that only supplies water during important rainfall events. Annual suspended sediment load at the catchment outlet oscillated between 615 and 3415 t y-1, with an average value of 2015 t y-1 (i.e. 9.3 t km-2 y-1). In contrast to the water yield, most of the suspended sediment load (i.e. 80%) is supplied from the driest part of the catchment where sediment availability is greater and there is a greater connectivity between sediment sources and the channel network. The humid part of the catchment only yielded the 20% of the sediment load, where, as in the case of the water yield, sediment yield is directly and

  13. 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

  14. 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, User’s Manual, Water Resource Investigations Report 83-4238, US Geological Survey, 1983]; (ii) the process based physiographic HRU-concept introduced by Flügel [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

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

    USGS Publications Warehouse

    Archfield, Stacey A.; Vogel, Richard M.

    2010-01-01

    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.

  16. 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

  17. What causes similarity in catchments?

    NASA Astrophysics Data System (ADS)

    Savenije, Hubert

    2014-05-01

    One of the biggest issues in hydrology is how to handle the heterogeneity of catchment properties at different scales. But is this really such a big issue? Is this problem not merely the consequence of how we conceptualise and how we model catchments? Is there not far more similarity than we observe. Maybe we are not looking at the right things or at the right scale to see the similarity. The identity of catchments is largely determined by: the landscape, the ecosystem living on the landscape, and the geology, in that order. Soils, which are often seen as a crucial aspect of hydrological behaviour, are far less important, as will be demonstrated. The main determinants of hydrological behaviour are: the landscape composition, the rooting depth and the phenology. These determinants are a consequence of landscape and ecosystem evolution, which, in turn, are the manifestations of entropy production. There are striking similarities between catchments. The different runoff processes from hillslopes are linked and similar in different environments (McDonnell, 2013). Wetlands behave similarly all over the world. The key is to classify landscapes and to link the ecosystems living on them to climate. The ecosystem then is the main controller of hydrological behaviour. Besides phenology, the rooting depth is key in determining runoff behaviour. Both are strongly linked to climate and much less to soil properties. An example is given of how rooting depth is determined by climate, and how rooting depth can be predicted without calibration, providing a strong constraints on the prediction of rainfall partitioning and catchment runoff.

  18. Landscape controls on spatiotemporal discharge variability in a boreal catchment

    NASA Astrophysics Data System (ADS)

    Karlsen, R. H.; Grabs, T.; Bishop, K.; Buffam, I.; Laudon, H.; Seibert, J.

    2016-08-01

    Improving the understanding of how stream flow dynamics are influenced by landscape characteristics, such as soils, vegetation and terrain, is a central endeavor of catchment hydrology. Here we investigate how spatial variability in stream flow is related to landscape characteristics using specific discharge time series from 14 partly nested subcatchments in the Krycklan basin (0.12 - 68 km2). Multivariate principal component analyses combined with univariate analyses showed that while variability in landscape characteristics and specific discharge were strongly related, the spatial patterns varied with season and wetness conditions. During spring snowmelt and at the annual scale, specific discharge was positively related to the sum of wetland and lake area. During summer, when flows are lowest, specific discharge was negatively related to catchment tree volume, but positively related to deeper sediment deposits and catchment area. The results indicate how more densely forested areas on till soils become relatively drier during summer months, while wet areas and deeper sediment soils maintain a higher summer base flow. Annual and seasonal differences in specific discharge can therefore be explained to a large extent by expected variability in evapotranspiration fluxes and snow accumulation. These analyses provide an organizing principle for how specific discharge varies spatially across the boreal landscape, and how this variation is manifested for different wetness conditions, seasons and time scales.

  19. The Neogene Forearc Basins of the Ecuadorian Shelf (1°N-2°20'S): Preliminary Interpretation of a Dense Grid of Mcs Data

    NASA Astrophysics Data System (ADS)

    Collot, J. Y.; Hernández Salazar, M. J.; Michaud, F.; Proust, J. N.; Ortega, R.; Aleman, A. M.

    2014-12-01

    Forearc basins serve as a sedimentary archive of sea-level variations and subduction-related tectonic processes. Along the Ecuadorian convergent margin (0°40'N-2°20'S) we interpreted a dense network (one profile every 4 km) of MCS reflection profiles acquired by the Ecuadorian State during the 2009 SCAN cruise with a 8-km-long, 640-channel streamer, and an array of 4000 in3total volume air guns to improve our understanding of the dynamic processes that shape forearc basin stratigraphy and tectonic structures. Isopach and structural maps of the acoustic basement show two structural segments on the margin. The northern segment (0°45'S-0°40'N) is characterized by - three sedimentary basins called Pedernales, Bahía-Jama and Caráquez basins, - N30°-50° trending transcurrent faults and -N80°-90° trending normal faults dipping to the south. The southern segment (2°S-0°45'S) is characterized by acoustic basement high, NS-trending until 1°10'S, with small localized sedimentary basins and by N320°-340° trending normal faults dipping to the north. At least five seismic units separated by unconformities are evidenced in the northern basins. Tentative correlations with geological data from the offshore Caraquez-1 well and the on-shore geology, suggest the following Neogene deformation steps: 1) sedimentary basins were initiated along N80°-90° trending normal faults in a regional N30°-50° trending strike slip system during lower Miocene; 2) deformation ended by a regional erosion (underlined by a flat regional unconformity) after the lower Miocene; 3) subsidence began by an undersea regional erosion after the Middle-Upper Miocene (underlined by an irregular regional unconformity), and 4) uplift and locally subsidence of the shelf edge with reactivation of a strike slip fault system from Pliocene (?) to Present. The arrival of the Carnegie ridge and associated seamounts to the trench axis is proposed at the origin of this last stage.

  20. Climate-vegetation-soil interactions and long-term hydrologic partitioning: Signatures of catchment co-evolution (Invited)

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    release time scales produce significantly more E/P. Vegetation in these catchments have longer access to this additional groundwater source and thus are less prone to water stress. Further analysis reveals that climates that give rise to more (less) E/P are associated with catchments that have vegetation with less (more) efficient water use parameters. In particular, the climates with tendency to produce more E/P have catchments that have lower % root fraction and less light use efficiency. Our results suggest that their exists strong interactions between climate, vegetation and soil properties that lead to specific hydrologic partitioning at the catchment scale. This co-evolution of catchment vegetation and soils with climate needs to be further explored to improve our capabilities to predict hydrologic partitioning in ungaged basins.

  1. Climate-vegetation-soil interactions and long-term hydrologic partitioning: signatures of catchment co-evolution

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    release time scales produce significantly more E/P. Vegetation in these catchments have longer access to this additional groundwater source and thus are less prone to water stress. Further analysis reveals that climates that give rise to more (less) E/P are associated with catchments that have vegetation with less (more) efficient water use parameters. In particular, the climates with tendency to produce more E/P have catchments that have lower % root fraction and less light use efficiency. Our results suggest that their exists strong interactions between climate, vegetation and soil properties that lead to specific hydrologic partitioning at the catchment scale. This co-evolution of catchment vegetation and soils with climate needs to be further explored to improve our capabilities to predict hydrologic partitioning in ungauged basins.

  2. 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.

  3. Impact of Drainage Basin Geology and Geomorphology on Detrital Thermochronometric Data from Modern River Sands: A Case Study in the Bhutan Himalaya

    NASA Astrophysics Data System (ADS)

    Coutand, I.; Whipp, D. M., Jr.; Bookhagen, B.; Grujic, D.

    2015-12-01

    Detrital thermochronology has become an important tool to quantify the erosional history of mountainous regions. Despite an increasing number of studies utilizing detrital records, it remains unclear how the record of spatially variable erosion of upstream drainage basins is preserved in the thermochronologic signal contained in the sediments. This important spatiotemporal problem is a first-order unknown that limits the interpretation of the geological significance of the detrital signal. To improve our understanding of detrital records in terms of spatiotemporal erosion rates, we use a three-step approach to study modern fluvial sediments from the Bhutan Himalaya. First, based on a preferred tectonomorphic scenario extracted by inversion of in situ multi-thermochronological ages, we predict apatite fission-track (AFT) age distributions in 18 catchments using the Pecube software. Second, we compare AFT age distributions from modern sand bars collected at each catchment outlet to distributions extracted from Monte Carlo sampling of the predicted catchment ages. We find that observed and predicted age distributions are statistically equivalent for only ~75% of the catchments. Third, we calculate predicted detrital age distributions by scaling the prevalence of ages in the catchment in proportion to topographic and climatic metrics (e.g., local relief, steepness index, specific stream power weighted by precipitation rate) or landslide-driven erosion to quantify their effects and relationships to the observed detrital AFT age distributions. Preliminary results suggest erosion in proportion to the topographic metrics cannot reproduce the observed age distributions, but bedrock landsliding may provide sufficient age variability to reproduce the observations. Ongoing work is determining whether variable target mineral concentrations in bedrock geological units or non-uniform sediment sourcing from moraine- or glacier-covered regions can reproduce the observed ages.

  4. 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

  5. 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.

  6. Creating a catchment scale perspective for river restoration

    NASA Astrophysics Data System (ADS)

    Benda, L.; Miller, D.; Barquín, 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.

  7. 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.

  8. 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

  9. 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.

  10. Spatio-temporal Hydrological Variability under Changing Climate in the Omo-Gibe River Basin of Ethiopia

    NASA Astrophysics Data System (ADS)

    Shiferaw, E.; Gebremichael, M.; Zagona, E. A.; Hailu, D.; Seyoum, S.

    2012-12-01

    Considering the use of water resource in a sustainable manner and forecasting the future likelihood patterns of this resource under different scenarios can help to mitigate and adapt the multi dimensional impact of climate change. Omo-Gibe River basin is one of the highest socio-economic development sites due to its numerous hydro potential for hydropower and irrigation. However, in recent years, the climate variations induced hydrological variability poses a challenge on decision making for planning and operation of hydropower plants. Hence, there should be a better understanding and projection of all the systems which can lead to a sustainable and optimal use of water for the intended purpose of generating power. The main goal of this study is to synthesize and understand future water resources distribution over space and time, and the extent of climate change induced hydrological variability impact on the generation capacity of the cascade hydropower plants in the Omo-Gibe River basin. An attempt has been made to collate historical and future projected downscaled climate data under different climatic scenarios from different sources. After applying hydrological modelling on the Omo-Gibe River basin with a catchment area of 79,000km2, preliminary result shows there is considerable hydrological variability over space and time which will have consequences on the generation capacity of the cascade hydropower plants across the basin.

  11. Monitoring and modeling of cold region hydrological processes in a high mountain river basin in the upstream area of the Heihe River Basin of China

    NASA Astrophysics Data System (ADS)

    Li, X.; Che, T.; Li, H.; Jin, R.; Liu, S.; Huang, C.

    2015-12-01

    We provide an overview of a high mountain river basin observing system in the Qilian Mountains of China. Mountain cryosphere is very sensitive to climate change, however, monitoring and modeling of cryospheric process and its interaction with hydrology and ecology needs to be further strengthened. We establish a multi-scale high mountain river basin observing system in the upstream area of the Heihe River Basin, Qilian Mountains of China. This system consists of flux towers on alpine tundra, alpine meadow and alpine steppes, a network of automatic meteorological stations, a wireless sensor network of soil moisture, soil temperature, snow depth, and precipitation, and two super observatories for monitoring snow and frozen soil, respectively. Super-high resolution (1 meter) DEMs of four experiment sub-watersheds (each about 20-40 km2) within this river basin were obtained via airborne LiDAR remote sensing.We introduce the data obtained since 2012 and present some preliminary modeling and data assimilation results. The results show that runoff, precipitation, snowmelt, and glacier melt keep increasing in the upstream area of the Heihe River Basin due to a warming climate. The ratio of snowmelt in total runoff has increased and the onset of snowmelt has gone ahead. The contribution of glacier melt to total runoff has almost doubled in the past decade. Frozen soil melt advances in time as well, and it may also contributes to the increase of the portion of baseflow in total runoff.This observatory has joined the International Network for Alpine Research Catchment Hydrology (NARCH) and will work as a unique site to monitor cryospheric and hydroclimatological changes in very high mountains.

  12. 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

  13. 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.

  14. Interpreting the suspended sediment dynamics in a mesoscale river basin of Central Mexico using a nested watershed approach

    NASA Astrophysics Data System (ADS)

    Duvert, C.; Némery, J.; Gratiot, N.; Prat, C.; Collet, L.; Esteves, M.

    2009-12-01

    The Cointzio river basin is located within the Mexican Transvolcanic Belt, in the Michoacán state. Land-use changes undergone over last decades lead to significant erosion processes, though affecting limited areas of the basin. Apart from generating a minor depletion of arable land by incising small headwater areas, this important sediment delivery contributed to siltation in the reservoir of Cointzio, situated right downstream of the basin. During 2009 rainy season, a detailed monitoring of water and sediment fluxes was undertaken in three headwater catchments located within the Cointzio basin (Huertitas, Potrerillos and La Cortina, respectively 2.5, 9.3 and 12.0 km2), as well as at the outlet of the main river basin (station of Santiago Undameo, 627 km2). Preliminary tests realized in 2008 underlined the necessity of carrying out a high-frequency monitoring strategy to assess the sediment dynamics in the basins of this region. In each site, water discharge time-series were obtained from continuous water-level measurements (5-min time-step), and stage-discharge rating curves. At the river basin outlet, Suspended Sediment Concentration (SSC) was estimated every 10 minutes through turbidity measurements calibrated with data from automatic sampling. In the three sub-catchments, SSC time-series were calculated using stage-triggered automatic water samplers. The three upland areas monitored in our study present distinct landforms, morphology and soil types. La Cortina is underlain by andisols, rich in organic matter and with an excellent microstructure under wet conditions. Huertitas and Potrerillos both present a severely gullied landscape, bare and highly susceptible to water erosion in degraded areas. As a result, suspended sediment yields in 2009 were expectedly much higher in these two sub-catchments (≈320 t.km-2 in Huertitas and ≈270 t.km-2 in Potrerillos) than in La Cortina (≈40 t.km-2). The total suspended sediment export was approximately of 30 t.km-2

  15. Model development based on a landscape oriented catchment unit concept

    NASA Astrophysics Data System (ADS)

    Cárdenas Gaudry, María.; Gutknecht, Dieter

    2010-05-01

    This paper is a companion paper to our project proposal "Hydrologic model framework for river basins with a range of hydroclimatic and bioclimatic conditions" (HS4.1). It intends to present a few ideas of how to bridge available concepts of landscape classification (as an example the Holdridge Life Zones classification scheme will be used) and hydrological approaches related to the Dominant Process Concept. The focus is on the development of landscape related indices that consider water balance characteristics (e.g.: the relationship ET/P), seasonality measures, and/or runoff generation process signatures at the landscape scale. Methods applied to consider runoff generation in hydrological modelling are commonly based on concepts such as the Hydrological Response Unit (HRU) concept (e.g. Flügel, 1995), the "hydrotop" concept (e.g. Reszler et al., 2006) and the Dominant Runoff Processes concept (DRP, e.g. Schmocker-Fackel and Scherrer, 2007). They are best suited to smaller scale catchment description. It is hypothesized here that additional/new concepts are necessary if the mechanismus that control runoff generation on a larger, i.e. regional scale should be captured. Hydrological reasoning and first results from regional studies indicate that appropiately chosen "signatures" can be found to characterise differences in the control of the runoff processes in different catchments situations. Examples might be "indicators" which include the soil moisture state of a basin or the event runoff coefficient derived from hydrological model simulatons or from runoff observations, respectly (e.g. Samuel et al. 2008; Merz & Blöschl, 2009a). The presentation will demostrate a few results from first studies on the above outlined concept. The study uses data from a set of Austrian catchments prepared for the studies reported in Merz & Blöschl (2009a). References: Flügel, W.-A. (1995): Delineating hydrological response units by geographical information system analyses for

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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 (Schöneben spring) emerging at the front of a RRG draining a catchment of 0.67 km² and discharges at gauging stations Finsterliesing and Unterwald further downstream with areal extents of 7.26 and 44.10 km² respectively are used as input for a lumped-parameter rainfall-runoff model, a modified version of the GR4J (Perrin et al., 2003). The Schöneben 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., Andréassian, V. (2003): Improvement of a parsimonious model for streamflow simulation. Journal of Hydrology 279, 275-289.

  1. Identifying critical source areas for phosphorus loss in Ireland using field and catchment scale ranking schemes

    NASA Astrophysics Data System (ADS)

    Hughes, K. J.; Magette, W. L.; Kurz, I.

    2005-03-01

    Phosphorus (P) in agricultural runoff is a major pollutant in many of Ireland's surface waters. Identification of areas that are at a high risk for P loss to surface waters is a critical component of river basin management. Two P ranking schemes (PRS's) were developed for Ireland, based on multi-criteria analysis approaches proposed in both the US and Europe, to predict the relative likelihood of P loss at both the field and catchment scales. The Field PRS was evaluated by comparing predicted rankings of potential P loss and transport against measured edge-of-field Dissolved Reactive P (DRP) loss for three fields with varying soil P levels. Qualitatively, results indicated that the Field PRS rankings corresponded to the magnitudes of measured P loss for the field sites, as well as to a reasoned evaluation of the relative likelihood that the fields would lose P that would subsequently make its way to surface water. The Catchment PRS was evaluated on a total of 31 catchments and sub-catchments by comparing predicted rankings of potential P loss and transport against measured in-stream median Molybdate Reactive P (MRP). Rankings of the relative likelihood of P loss and transport predicted by the Catchment PRS were positively correlated with median in-stream MRP ( r=0.51, P<0.05). Although the data available for these evaluations were limited, especially at field scale, and further research may identify the opportunity for modifications, both field and catchment scale P ranking schemes demonstrated a potential for identifying critical P source areas within catchments dominated by grass-based agricultural production systems, such as those in Ireland.

  2. Mean water residence times in the pre-alpine Rietholzbach catchment

    NASA Astrophysics Data System (ADS)

    Lehner, I.; Bernasconi, S.; Seneviratne, S. I.

    2009-04-01

    The Rietholzbach catchment is a small, hilly pre-alpine basin in the north-eastern part of Switzerland. Its area is 3.31 km2 and it covers an altitude range between 682 and 950 m. The area is only sparsely populated and primarily used as pasture land (67 %), on steep slopes the land use is forest (25 %). A hydrological peculiarity is the congruence of surface and sub-surface catchment area. In 1975 measurements were initiated to determine and understand the water balance and its processes. Isotope measurements of all components of the water cycle started in 1994. The water samples of precipitation, soil water (discharge of a lysimeter), ground water, and river water are taken approximately bi-weekly. All samples are prepared by the CO2 gas equilibration technique and are analysed in terms of the oxygen isotopes by mass spectrometry. The samples are taken either at the gauge at the outflow of the catchment or next to the main measurement site in the upper third of the catchment where an other gauge, three groundwater wells, the lysimeter and the meteorological sensors are installed in close vicinity. Based on these data series this contribution will present estimates of the mean water residence times in the different components of the catchment.

  3. Seasonalstreamflow Generation At Variousspatial Scales On A Smallmediterranean Vineyard Catchment

    NASA Astrophysics Data System (ADS)

    Marofi, S.; Moussa, R.; Voltz, M.

    The importance of surface hydrological processes, under field and sub-catchment conditions, was examines on a small-cultivated watershed, located in South of France. Hydrological responses at different spatial scales were evaluated during the wetness and drier phases, which included the within-year and the long-term periods. The experimental design involved monitoring of surface runoff, streamflow and groundwaters behaviours, in response to rainfall events, during three hydrological cycles. In addition to the mean outlet of catchment and the two vineyard fields that have different situations, runoff was measured at 8 sub-catchments of site. Rainfall was monitored on continuous basis at 4 sites, and the water tables fluctuations also were recorded in more than 15 locations of catchment. During the experimentation period, more than 175 rainy events were observed. The dates analyse show that the regime of surface water, compound of three principals phases: (i) the phases of great flow circulation, (ii) the recession phases, and (iii) the phase without surface flow. The results also indicate that the annual runoff changes appreciably according to hydrological cycles and the rainfall variability. It varies from 28% to 50% of the total of precipitation. The inter-annual variations of the runoff also recovers that the annual runoff flow is insured for approximately 40% by the instantaneous floods, which occur the moment or a few hours only after precipitation, and about 60% by the recession periods, which take place for the long time after floods. The flood events were classified in three groups, differentiated by the initial water table levels and their occurrence period. The direct runoff and the baseflow calculation show that according to the type of flood, they change respectively from 7% to17% and 0% to 7% of precipitation. Comparing to the field areas, on average, the total runoff and direct runoff of the mean basin respectively are 46% and 35%. The water flow

  4. Catchment classification by means of hydrological models

    NASA Astrophysics Data System (ADS)

    Hellebrand, Hugo; Ley, Rita; Casper, Markus

    2013-04-01

    An important hydrological objective is catchment classification that will serve as a basis for the regionalisation of discharge parameters or model parameters. The main task of this study is the development and assessment of two classification approaches with respect to their efficiency in catchment classification. The study area in western Germany comprises about 80 catchments that range in size from 8 km2 up to 1500 km2, covering a wide range of geological substrata, soils, landscapes and mean annual precipitation. In a first approach Self Organising Maps (SOMs) use discharge characteristics or catchment characteristics to classify the catchments of the study area. Next, a reference hydrological model calibrates the catchments of the study area and tests the possibilities of parameter transfer. Compared to the transfer of parameters outside a class, for most catchments the model performance improves when parameters within a class are transferred. Thus, it should be possible to distinguish catchment classes by means of a hydrological model. The classification results of the SOM are compared to the classification results of the reference hydrological model in order to determine the latter validity. The second approach builds on the first approach in such a way that it uses the Superflex Modelling Framework instead of only one reference model. Within this framework multiple conceptual model structures can be calibrated and adapted. Input data for each calibration of a catchment are hourly time series of runoff, precipitation and evaporation for at least eight years. The calibration of multiple models for each catchment and their comparison allows for the assessment of the influence of different model structures on model performance. Learning loops analyse model performance and adapt model structures accordingly with a view to performance improvement. The result of the modelling exercise is a best performing model structure for each catchment that serves as a basis

  5. Winter streamflow analysis in frozen, alpine catchments to quantify groundwater contribution and properties

    NASA Astrophysics Data System (ADS)

    Stoelzle, Michael; Weiler, Markus

    2016-04-01

    contributions is helpful to assess the water sustainability of alpine catchments functioning as water towers for downstream water basins. We outline how well-known hydrograph and recession analyses in alpine catchments can help to explore the role of catchment storage and to advance our understanding of (ground-)water management in alpine environments.

  6. 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.

  7. Dissolved and particulate nutrient export from rural catchments: a case study from Luxembourg.

    PubMed

    Salvia-Castellví, Mercè; Iffly, Jean François; Borght, Paul Vander; Hoffmann, Lucien

    2005-05-15

    Nutrient enrichment of freshwaters continues to be one of the most serious problems facing the management of surface waters. Effective remediation/conservation measures require accurate qualitative and quantitative knowledge of nutrient sources, transport mechanisms, transformations and annual dynamics of different nitrogen (N) and phosphorus (P) forms. In this paper, nitrate (NO3-N), soluble reactive phosphorus (SRP) and total phosphorus (TP) concentrations and loads are presented for two adjacent rural basins of 306 km2 and 424 km2, and for five sub-basins differing in size (between 1 km2 and 33 km2), land use (extent of forest cover between 20% and 93%) and household pressure (from 0 to 40 people/km2) with the aim of studying the influence of land use and catchment size on nutrient exports. The studied catchments are all situated on Devonian schistous substrates in the Ardennes region (Belgium-Luxembourg), and therefore have similar hydrological regimes. As the study period could not be the same for all basins, annual export coefficients were corrected with the 25 years normalized discharge of the Sure River: two regression analyses (for dry and humid periods) relating monthly nutrient loads to monthly runoff were used to determine correction factors to be applied to each parameter and each basin. This procedure allows for the comparing annual export coefficients from basins sampled in different years. Results show a marked seasonal response and a large variability of NO3-N export loads between forested (4 kg N ha-1 year-1), agricultural (27-33 kg N ha-1 year-1) and mixed catchments (17-22 kg N ha-1 year-1). For SRP and TP, no significant agricultural impact was found. Land and bank erosion control the total P massflow in the studied catchments (0.4-1.3 kg P ha-1 year-1), which is mostly in a particulate form, detached and transported during storm events. Soluble reactive P fluxes ranged between 10% and 30% of the TP mass, depending on the importance of point

  8. 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.

  9. Coupling soil moisture and precipitation observations for predicting hourly runoff at small catchment scale

    NASA Astrophysics Data System (ADS)

    Tayfur, Gokmen; Zucco, Graziano; Brocca, Luca; Moramarco, Tommaso

    2014-03-01

    The importance of soil moisture is recognized in rainfall-runoff processes. This study quantitatively investigates the use of soil moisture measured at 10, 20, and 40 cm soil depths along with rainfall in predicting runoff. For this purpose, two small sub-catchments of Tiber River Basin, in Italy, were instrumented during periods of October 2002-March 2003 and January-April 2004. Colorso Basin is about 13 km2 and Niccone basin 137 km2. Rainfall plus soil moisture at 10, 20, and 40 cm formed the input vector while the discharge was the target output in the model of generalized regression neural network (GRNN). The model for each basin was calibrated and tested using October 2002-March 2003 data. The calibrated and tested GRNN was then employed to predict runoff for each basin for the period of January-April 2004. The model performance was found to be satisfactory with determination coefficient, R2, equal to 0.87 and Nash-Sutcliffe efficiency, NS, equal to 0.86 in the validation phase for both catchments. The investigation of effects of soil moisture on runoff prediction revealed that the addition of soil moisture data, along with rainfall, tremendously improves the performance of the model. The sensitivity analysis indicated that the use of soil moisture data at different depths allows to preserve the memory of the system thus having a similar effect of employing the past values of rainfall, but with improved GRNN performance.

  10. 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 (δ18O and δ2H) 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

  11. 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.

  12. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Level 3 Ecoregions

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  13. Attributes for NHDplus Catchments (Version 1.1) for the Conterminous United States: Population Density, 2000

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  14. Attributes for NHDPlus Catchments (Version 1.1) in the Conterminous United States: Bedrock Geology

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  15. Attributes for NHDPlus Catchments (Version 1.1): Level 3 Nutrient Ecoregions, 2002

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  16. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Hydrologic Landscape Regions

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  17. Attributes for NHDPlus catchments (Version 1.1) for the conterminous United States: STATSGO soil characteristics

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  18. Attributes for NHDPlus catchments (version 1.1) for the conterminous United States: surficial geology

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  19. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Physiographic Provinces

    USGS Publications Warehouse

    Wieczorek, Michael; 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

  20. 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.

  1. 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.

  2. 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

    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.

  3. Use of modeling to protect, plan, and manage water resources in catchment areas.

    PubMed

    Constant, Thibaut; Charrière, Séverine; Lioeddine, Abdejalil; Emsellem, Yves

    2016-08-01

    The degradation of water resources by diffuse pollution, mainly due to nitrate and pesticides, is an important matter for public health. Restoration of the quality of natural water catchments by focusing on their catchment areas is therefore a national priority in France. To consider catchment areas as homogeneous and to expend an equal effort on the entire area inevitably leads to a waste of time and money, and restorative actions may not be as efficient as intended. The variability of the pedological and geological properties of the area is actually an opportunity to invest effort on smaller areas, simply because every action is not equally efficient on every kind of pedological or geological surface. Using this approach, it is possible to invest in a few selected zones that will be efficient in terms of environmental results. The contributive hydraulic areas (CHA) concept is different from that of the catchment area. Because the transport of most of the mobile and persistent pollutants is primarily driven by water circulation, the concept of the CHA is based on the water pathway from the surface of the soil in the catchment area to the well. The method uses a three-dimensional hydrogeological model of surface and groundwater integrated with a geographic information system called Watermodel. The model calculates the contribution (m(3)/h or %) of each point of the soil to the total flow pumped in a well. Application of this model, partially funded by the Seine Normandy Basin Agency, to the catchment of the Dormelles Well in the Cretaceous chalk aquifer in the Orvanne valley, France (catchment area of 23,000 ha at Dormelles, county 77), shows that 95 % of the water pumped at the Dormelles Well comes from only 26 % of the total surface area of the catchment. Consequently, an action plan to protect the water resource will be targeted at the 93 farmers operating in this source area rather than the total number of farmers (250) across the entire 23,000 ha. Another

  4. 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

  5. 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

  6. 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

  7. 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)

  8. Field observations of vertical temperature/humidity structure in the Cerdanya Basin -Spanish Pyrenees: Preliminary results and comparison with model forecasts

    NASA Astrophysics Data System (ADS)

    Miró, Josep Ramon; Pepin, Nick

    2016-04-01

    The Cerdanya basin is located in the north-eastern Pyrenees and measures 15 km wide and 40 km long. It is unique in that its north-east to south-west orientation contrasts with most other Pyrenean valleys which run north-south. The upper portion has its valley bottom averaging around 1000 m asl, with the surrounding mountain ranges rising to well over 2000 m asl. To the west (downstream) the Segre flows into a narrow gorge which provides a constriction for any down-valley flow. This topography encourages intense temperature inversions through cold air ponding, decoupling the valley atmosphere from the regional circulation, especially in winter. Prediction of minimum temperatures is a challenge. A network of 40 temperature sensors was installed in 2012 to collect hourly temperatures throughout the cold pool. A transect was also installed in Conflent to the north-east as a comparison, since previous research has shown that the vertical temperature and humidity profiles are less influenced by cold air drainage in this valley system. The sensor data is validated against AWS observations at two contrasting locations. Using two years of data (2012-2014), through calculation of hourly lapse rates in various elevation bands we show frequent inversions developing up to 1450 m, and sometimes extending much higher than this, concentrating in winter. Accumulated potential temperature deficit is shown to be much higher in Cerdanya than in Conflent, and increases in the lower atmospheric layers. Case studies of two intense episodes in December 2012 and January 2013 show that model simulations, despite being able to simulate broad mechanisms of the CAP formation and thermal winds, underestimate the amount of cooling, particularly in incised valley locations.

  9. Improved simulation of groundwater - surface water interaction in catchment models

    NASA Astrophysics Data System (ADS)

    teklesadik, aklilu; van Griensven, Ann; Anibas, Christian; Huysmans, Marijke

    2016-04-01

    Groundwater storage can have a significant contribution to stream flow, therefore a thorough understanding of the groundwater surface water interaction is of prime important when doing catchment modeling. The aim of this study is to improve the simulation of groundwater - surface water interaction in a catchment model of the upper Zenne River basin located in Belgium. To achieve this objective we used the "Groundwater-Surface water Flow" (GSFLOW) modeling software, which is an integration of the surface water modeling tool "Precipitation and Runoff Modeling system" (PRMS) and the groundwater modeling tool MODFLOW. For this case study, the PRMS model and MODFLOW model were built and calibrated independently. The PRMS upper Zenne River basin model is divided into 84 hydrological response units (HRUs) and is calibrated with flow data at the Tubize gauging station. The spatial discretization of the MODFLOW upper Zenne groundwater flow model consists of 100m grids. Natural groundwater divides and the Brussels-Charleroi canal are used as boundary conditions for the MODFLOW model. The model is calibrated using piezometric data. The GSFLOW results were evaluated against a SWAT model application and field observations of groundwater-surface water interactions along a cross section of the Zenne River and riparian zone. The field observations confirm that there is no exchange of groundwater beyond the Brussel-Charleroi canal and that the interaction at the river bed is relatively low. The results show that there is a significant difference in the groundwater simulations when using GSFLOW versus SWAT. This indicates that the groundwater component representation in the SWAT model could be improved and that a more realistic implementation of the interactions between groundwater and surface water is advisable. This could be achieved by integrating SWAT and MODFLOW.

  10. Water quantity and quality optimization modeling of dams operation based on SWAT in Wenyu River Catchment, China.

    PubMed

    Zhang, Yongyong; Xia, Jun; Chen, Junfeng; Zhang, Minghua

    2011-02-01

    Water quantity and quality joint operation is a new mode in the present dams' operation research. It has become a hot topic in governmental efforts toward integrated basin improvement. This paper coupled a water quantity and quality joint operation model (QCmode) and genetic algorithm with Soil and Water Assessment Tool (SWAT). Together, these tools were used to explore a reasonable operation of dams and floodgates at the basin scale. Wenyu River Catchment, a key area in Beijing, was selected as the case study. Results showed that the coupled water quantity and quality model of Wenyu River Catchment more realistically simulates the process of water quantity and quality control by dams and floodgates. This integrated model provides the foundation for research of water quantity and quality optimization on dam operation in Wenyu River Catchment. The results of this modeling also suggest that current water quality of Wenyu River will improve following the implementation of the optimized operation of the main dams and floodgates. By pollution control and water quantity and quality joint operation of dams and floodgates, water quality of Wenyu river will change significantly, and the available water resources will increase by 134%, 32%, 17%, and 82% at the downstream sites of Sha River Reservoir, Lutong Floodgate, Xinpu Floodgate, and Weigou Floodgate, respectively. The water quantity and quality joint operation of dams will play an active role in improving water quality and water use efficiency in Wenyu River Basin. The research will provide the technical support for water pollution control and ecological restoration in Wenyu River Catchment and could be applied to other basins with large number of dams. Its application to the Wenyu River Catchment has a great significance for the sustainable economic development of Beijing City.

  11. 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

  12. Estimating catchment evaporation and runoff using MODIS leaf area index and the Penman-Monteith equation

    NASA Astrophysics Data System (ADS)

    Zhang, Y. Q.; Chiew, F. H. S.; Zhang, L.; Leuning, R.; Cleugh, H. A.

    2008-10-01

    This paper shows the feasibility of using steady state water balances of gauged catchments to calibrate a spatially explicit evaporation model and then applying this to estimate mean annual runoff for 120 gauged catchments in the Murray-Darling Basin (MDB) of Australia from 2001 to 2005. We used remotely sensed leaf area indices from the Moderate Resolution Imaging Spectrometer (MODIS) mounted on the polar-orbiting Terra satellite with the Penman-Monteith equation, gridded meteorology, and a two-parameter biophysical model for surface conductance (Gs) to estimate 8-day average evaporation at 1-km resolution. Parameters for the Gs model were optimized using steady state water balance estimates (precipitation minus runoff) in the gauged catchments in three precipitation zones of the MDB, and the calibrated evaporation model was then used to estimate evaporation (ERS) and runoff from gauged and ungauged catchments in the MDB. Mean annual calibrated estimates of ERS compared well with water balance estimates, indicated by a root-mean-square error (RMSE) of 78.6 mm/a and the Nash-Sutcliffe coefficient of efficiency (CE) of 0.68. Reasonable agreement was obtained between the estimated mean annual runoff (RRS) (rainfall minus ERS), and the measured runoff (RMSE = 71.0 mm/a and CE = 0.75). Cross validation showed that estimated ERS and RRS were almost as good as the calibrated ones. Furthermore, RRS has an accuracy similar to that of a seven-parameter conceptual rainfall-runoff model in the gauged catchments. The results show that the evaporation model can be easily applied to estimate steady state evaporation and runoff and that ERS can be used with rainfall-runoff models to improve accuracy of estimated runoff in ungauged catchments.

  13. Hydrologic Transit Times in Tropical Montane Watersheds: Catchment Scale and Landscape Influences

    NASA Astrophysics Data System (ADS)

    Munoz Villers, L. E.; Geissert Kientz, D. R.; Holwerda, F.; McDonnell, J.

    2015-12-01

    Stream water mean transit time (MTT) is a fundamental hydrologic parameter that integrates the distribution of sources, flow paths and storages present in catchments. However, in the tropics little work has been carried out on MTT, despite its usefulness for providing important information about watershed hydrological functioning at different spatial scales in (largely) ungauged basins. In particular, very few studies have quantified stream MTTs and related to catchment characteristics in tropical montane regions. Here we examined topographic, land use/cover and soil hydraulic controls on baseflow MTT for nested watersheds (0.1-34 km2) within a humid mountainous region, underlain by volcanic soil (Andisols) in central Veracruz (eastern Mexico). To estimate MTTs, we used a 2 year record of bi-weekly isotopic composition of precipitation and stream baseflow data. Land use/cover and topographic parameters were derived from GIS analysis. Soil profile hydraulic properties and permeability at the soil-bedrock interface were obtained from intensive field measurements and laboratory analysis. Estimates of baseflow MTT ranged between 1.2 and 2.7 years across the 12 study catchments. Major differences in MTTs were found at the small (0.1-1.5 km2) and at the large scales (14-34 km2), related mostly to catchment slope and morphology and, to much lesser extent, to land cover. Interestingly, longest stream MTTs were found in the cloud forest headwater catchments. Overall, MTTs were mainly controlled by depth to bedrock associated with topography, and permeability at the soil-bedrock interface. Mid and ridge hillslope positions appeared to be the main contributing areas for catchment recharge and runoff. The present study is the first step towards to understand the hydrology and subsurface processes across scales in this tropical environment, with the aim to support decisions for local and regional management water supply under increasing land use and climate change pressures.

  14. SWAT model application in a data scarce tropical complex catchment in Tanzania

    NASA Astrophysics Data System (ADS)

    Ndomba, Preksedis; Mtalo, Felix; Killingtveit, Aanund

    This study intended to validate the Soil and Water Assessment Tool (SWAT) model in data scarce environment in a complex tropical catchment in the Pangani River Basin located in northeast Tanzania. The validation process involved the model initialization, calibration, verification and sensitivity analysis. Both manual and auto-calibration procedures were used to facilitate the comparison of the results with past studies in the same catchment. For this study, some model parameters including Soil depth (SOL_Z) and Saturated hydraulic conductivity (SOL_K) were assumed uniform within the study catchment and were therefore lumped comprising the huge computation resource requirement of the SWAT model. Results indicated that the same set of important parameters was identified with or without the use of observed flows data. Some of the parameters had physical interpretation and could therefore relate directly to hydrological controlling factors within the catchment. Despite swapping ranking importance of parameters, these results suggest the suitability of the SWAT model for identifying hydrological controlling factors/parameters in ungauged catchments. Results of calibration and validation at the daily timescale gave moderately satisfactory Nash-Sutcliffe Coefficient of Efficiency (CE) of 54.6% for calibration and 68% for validation while simulated and observed mean annual flow discharges gave an Index of Volumetric Fit (IVF) of 100%. The study further indicated the improvement of model estimation when more reliable spatial representation of rainfall was used. Although in this study SWAT model has performed satisfactorily in data poor and complex catchment, the authors recommend a wider validation effort of the model before it is adopted for operational purpose.

  15. The relationship between soil heterotrophic activity, soil dissolved organic carbon (DOC) leachate, and catchment-scale DOC export in headwater catchments

    USGS Publications Warehouse

    Brooks, P.D.; McKnight, Diane M.; Bencala, K.E.

    1999-01-01

    Dissolved organic carbon (DOC) from terrestrial sources forms the major component of the annual carbon budget in many headwater streams. In high-elevation catchments in the Rocky Mountains, DOC originates in the upper soil horizons and is flushed to the stream primarily during spring snowmelt. To identify controls on the size of the mobile soil DOC pool available to be transported during the annual melt event, we measured soil DOC production across a range of vegetation communities and soil types together with catchment DOC export in paired watersheds in Summit County, Colorado. Both surface water DOC concentrations and watershed DOC export were lower in areas where pyrite weathering resulted in lower soil pH. Similarly, the amount of DOC leached from organic soils was significantly smaller (p < 0.01) at sites having low soil p H. Scaling point source measurements of DOC production and leaching to the two basins and assuming only vegetated areas contribute to DOC production, we calculated that the amount of mobile DOC available to be leached to surface water during melt was 20.3 g C m-2 in the circumneutral basin and 17.8 g C m-2 in the catchment characterized by pyrite weathering. The significant (r2 = 0.91 and p < 0.05), linear relationship between overwinter CO2 flux and the amount of DOC leached from upper soil horizons during snowmelt suggests that the mechanism for the difference in production of mobile DOC was heterotrophic processing of soil carbon in snow-covered soil. Furthermore, this strong relationship between over-winter heterotrophic activity and the size of the mobile DOC pool present in a range of soil and vegetation types provides a likely mechanism for explaining the interannual variability of DOC export observed in high-elevation catchments.

  16. Hydrothermal deposits in the Southern Trough of Guaymas Basin, Gulf of California: Observations and Preliminary Results from the 2003 MBARI Dive Program

    NASA Astrophysics Data System (ADS)

    Stakes, D. S.; Tivey, M. K.; Koski, R. A.; Ortego-Osorio, A.; Preston, C. M.; McCulloch, M. T.; Nakamura, K.; Seewald, J.; Wheat, C. G.

    2003-12-01

    During Leg 2 of the 2003 MBARI expedition to the Gulf of California, the ROV Tiburon completed eight dives to active vent fields in the Southern Trough of Guaymas Basin. Six venting areas were investigated in detail. Tiburon operations included (1) sampling mineral deposits that range from mini-chimneys a few centimeters high to 10-meter-tall sulfide-carbonate structures with wide flanges; (2) collection of 90C to 303C methane, carbon dioxide, and hydrogen-rich vent fluids in gas-tight samplers and plume-laden particulates in Niskin samplers; 3) collection of warm (up to 83C) hydrocarbon-rich sediment push cores; 4) long-term monitoring of three vent sites using thermocouple arrays (see adjacent Tivey et al poster) and osmotically-driven fluid samplers. Seventy days later, the ROV returned to recover the thermocouple arrays and ingrown chimneys. At the lowest temperature sites, fluid (up to 90C) discharged from orifices in sediment surrounded by white to yellow microbial mats. Combined Eh-ISUS (InSitu Ultraviolet Spectrophotometer) sensors mounted on Tiburon identified local increases in bisulfide and decreases in the oxidation/reduction potential (a proxy for methane and hydrogen sulfide) associated with these sites. Massive barite chimneys recovered from the margins of moderate-temperature vent sites are permeated with oil. Chimneys from higher temperature sites, in contrast, lack the liquid hydrocarbon component, and are largely composed of calcium carbonate with lesser anhydrite, amorphous silica, barite, pyrrhotite, Mg-silicate, galena, sphalerite, and chalcopyrite. Mineral precipitation at the southernmost site (Toadstool) is characterized by the formation of carbonate-rich flanges directly above a substrate of altered diatomaceous sediment. The upper sediment crust lies above a stockwork of calcite veins. High-temperature structures at Rebecca's Roost and Broken Mushroom have pagoda-like carbonate-rich flanges trapping pools of hydrothermal fluids that

  17. 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

  18. Modelling hydrology and water quality in a Mediterranean catchment

    NASA Astrophysics Data System (ADS)

    Candela, Angela; Viviani, Gaspare

    2010-05-01

    In this study the SWAT model has been used in order to analyse and quantify pollution dynamics at basin scale depending on concentrated and diffuse sources. Nowadays, the receiving water bodies quality safeguarding is of growing importance due to the promulgation of recent laws as well as the growing sensitivity regarding the environment issues by the scientific and practitioner committee. Recently the EU 2000/60 (Water Framework Directive) makes the analysis of receiving water bodies even more complex by integrating the pollution in urban areas in a framework of the pollution sources at catchment scale. and making necessary further integration of environmental impacts associated with discharges concentrates civilian and productive with the widespread pollution linked mainly to agriculture and zoo-technical activities. The complexity of natural systems and the large number of polluting sources and variables to be monitored requires the adoption of models able to get a better view of the whole system in a simplified way without neglecting the most important physical phenomena. Particularly, in this study the SWAT model was considered since it is an integrated hydrological model that are, nowadays, needed to support the implementation of integrated water management plans and to comply with the current requirements of the WFD. In addition, the SWAT model is interfaced with the ARC-VIEW software which allows easy pre-and post processing of the spatially distributed input data, driving the rainfall-runoff process. The model has been applied to the experimental Nocella catchment located in Sicily (Italy), with an area of about 50 km2. The river receives wastewater and stormwater from two urban areas drained by combined sewers. The study demonstrates that the analysis of water quality in partially urbanised natural basins is complex depending on variable polluting contributions of the different parts of the system depending on specific polluting compounds. The model was

  19. A perspective on stream-catchment connections

    USGS Publications Warehouse

    Bencala, Kenneth E.

    1993-01-01

    Ecological study of the hyporheic zone is leading to recognition of a need for additional hydrologic understanding. Some of this understanding can be obtained by viewing the hyporheic zone as a succession of isolated boxes adjacent to the stream. Further understanding, particularly relevant to catchment-scale ecology, may come from studies focussed on the fluid mechanics of the flow-path connections between streams and their catchments.

  20. Preliminary geochemical assessment of water in selected streams, springs, and caves in the Upper Baker and Snake Creek drainages in Great Basin National Park, Nevada, 2009

    USGS Publications Warehouse

    Paul, Angela P.; Thodal, Carl E.; Baker, Gretchen M.; Lico, Michael S.; Prudic, David E.

    2014-01-01

    Water in caves, discharging from springs, and flowing in streams in the upper Baker and Snake Creek drainages are important natural resources in Great Basin National Park, Nevada. Water and rock samples were collected from 15 sites during February 2009 as part of a series of investigations evaluating the potential for water resource depletion in the park resulting from the current and proposed groundwater withdrawals. This report summarizes general geochemical characteristics of water samples collected from the upper Baker and Snake Creek drainages for eventual use in evaluating possible hydrologic connections between the streams and selected caves and springs discharging in limestone terrain within each watershed.Generally, water discharging from selected springs in the upper Baker and Snake Creek watersheds is relatively young and, in some cases, has similar chemical characteristics to water collected from associated streams. In the upper Baker Creek drainage, geochemical data suggest possible hydrologic connections between Baker Creek and selected springs and caves along it. The analytical results for water samples collected from Wheelers Deep and Model Caves show characteristics similar to those from Baker Creek, suggesting a hydrologic connection between the creek and caves, a finding previously documented by other researchers. Generally, geochemical evidence does not support a connection between water flowing in Pole Canyon Creek to that in Model Cave, at least not to any appreciable extent. The water sample collected from Rosethorn Spring had relatively high concentrations of many of the constituents sampled as part of this study. This finding was expected as the water from the spring travelled through alluvium prior to being discharged at the surface and, as a result, was provided the opportunity to interact with soil minerals with which it came into contact. Isotopic evidence does not preclude a connection between Baker Creek and the water discharging from

  1. Hydrology and sediment yield calibration for the Barasona reservoir catchment (Spain) using SWAT

    NASA Astrophysics Data System (ADS)

    Palazón, Leticia; Navas, Ana

    2013-04-01

    Hydrological and soil erosion models, as Soil and Water Assessment Tool (SWAT), have become very useful tools and increasingly serve as vital components of integrated environmental assessments that provide information outside of direct field experiments and causal observation. The purpose of this study was to improve the calibration of SWAT model to use it in an alpine catchment as a simulator of processes related to water quality and soil erosion. SWAT is spatially semi-distributed, agro-hydrological model that operates on a daily time step (as a minimum) at basin scale. It is designed to predict the impact of management on water, sediment and agricultural chemical yields in ungaged catchments. SWAT provides physically based algorithms as an option to define many of the important components of the hydrologic cycle. The input requirements of the model are used to describe the climate, soil properties, topography, vegetation, and land management practices. SWAT analyzes small or large catchments by discretising into sub-basins, which are then further subdivided into hydrological response units (HRUs) with homogeneous land use, soil type and slope. SWAT model (SWAT2009) coupled with a GIS interface (ArcSWAT), was applied to the Barasona reservoir catchment located in the central Spanish Pyrenees. The 1509 km2 agro-forestry catchment presents a mountain type climate, an altitudinal range close to 3000 meters and a precipitation variation close to 1000 mm/km. The mountainous characteristics of the catchment, in addition to the scarcity of climate data in the region, require specific calibration for some processes. Snowfall and snowmelt are significant processes in the hydrologic regime of the area and were calibrated in a previous work. In this work some of the challenges of the catchment to model with SWAT which affected the hydrology and the sediment yield simulation were performed as improvement of the previous calibration. Two reservoirs, a karst system which

  2. Modelling fate and transport of glyphosate and AMPA in the Meuse catchment to assess the contribution of different pollution sources

    NASA Astrophysics Data System (ADS)

    Desmet, Nele; Seuntjens, Piet

    2013-04-01

    Large river basins have multiple sources of pesticides and usually the pollution sources are spread over the entire catchment. The cumulative effect of pesticides entering the river system in upstream areas and the formation of persistent degradation products can compromise downstream water use e.g. raw water quality for drinking water abstractions. For assessments at catchment scale pesticide fluxes coming from different sources and sub basins need to be taken into account. To improve management strategies, a sound understanding of the sources, emission routes, transport, environmental fate and conversion of pesticides is needed. In the Netherlands, the Meuse river basin is an important source for drinking water production. The river suffers from elevated concentrations of glyphosate and aminomethylphosphonic acid (AMPA). For AMPA it is rather unclear to what extent the pollution is related to glyphosate degradation and what is the contribution of other sources, especial phosphonates in domestic and industrial waste water. Based on the available monitoring data only it is difficult to distinguish between AMPA sources in such a large river basin. This hampers interpretation and decision making for water quality management in the Meuse catchment. Here, application of water quality models is very useful to obtain complementary information and insights. Modelling allows accounting for temporal and spatial variability in discharge and concentrations as well as distinguishing the contribution from conversion processes. In this study, a model for the river Meuse was developed and applied to assess the contribution of tributary and transnational influxes, glyphosate degradation and other sources to the AMPA pollution.

  3. Simulating the effect of vegetation cover on the sediment yield of mediterranean catchments using SHETRAN

    NASA Astrophysics Data System (ADS)

    Lukey, B. T.; Sheffield, J.; Bathurst, J. C.; Lavabre, J.; Mathys, N.; Martin, C.

    1995-08-01

    The sediment yield of two catchments in southern France was modelled using the newly developed sediment code of SHETRAN. A fire in August 1990 denuded the Rimbaud catchment, providing an opportunity to study the effect of vegetation cover on sediment yield by running the model for both pre-and post-fire cases. Model output is in the form of upper and lower bounds on sediment discharge, reflecting the uncertainty in the erodibility of the soil. The results are encouraging since measured sediment discharge falls largely between the predicted bounds, and simulated sediment yield is dramatically lower for the catchment before the fire which matches observation. SHETRAN is also applied to the Laval catchment, which is subject to Badlands gulley erosion. Again using the principle of generating upper and lower bounds on sediment discharge, the model is shown to be capable of predicting the bulk sediment discharge over periods of months. To simulate the effect of reforestation, the model is run with vegetation cover equivalent to a neighbouring fully forested basin. The results obtained indicate that SHETRAN provides a powerful tool for predicting the impact of environmental change and land management on sediment yield.

  4. Pollution indicators in groundwater of two agricultural catchments in Lower Silesia (Poland)

    NASA Astrophysics Data System (ADS)

    Kasperczyk, Lidia; Modelska, Magdalena; Staśko, Stanisław

    2016-12-01

    The article discusses the content and source of mineral nitrogen compounds in groundwater, based on the data collected in two river catchments in two series (spring and autumn 2014). The study area comprises two catchments located in Lower Silesia, Poland - Cicha Woda and Sąsiecznica. Both catchments are characterised agricultural character of development. In the both researched areas, the points of State Environmental Monitoring (SEM) are located but only the Cicha Woda area is classified as nitrate vulnerable zone (NVZ). To analyse and compare the contamination of Quaternary and Neogene aquifers, the concentration of nitrates, nitrites, ammonium and potassium ions was measured primarily. Results showed the exceedance of nitrogen mineral forms of shallow groundwater Quaternary aquifer in both basins. The concentration of nitrates range from 0.08 to 142.12 mgNO3 -/dm3 (Cicha Woda) and from 2.6 to 137.65 mg NO3 -/dm3 (Sąsiecznica). The major source of pollution is probably the intensive agriculture activity. It causes a degradation of the shallow groundwater because of nitrate, nitrite, potassium, phosphates and ammonium contents. There was no observed contamination of anthropogenic origin in the deeper Neogene aquifer of Cicha Woda catchment.

  5. Review article: Hydrological modeling in glacierized catchments of central Asia - status and challenges

    NASA Astrophysics Data System (ADS)

    Chen, Yaning; Li, Weihong; Fang, Gonghuan; Li, Zhi

    2017-02-01

    Meltwater from glacierized catchments is one of the most important water supplies in central Asia. Therefore, the effects of climate change on glaciers and snow cover will have increasingly significant consequences for runoff. Hydrological modeling has become an indispensable research approach to water resources management in large glacierized river basins, but there is a lack of focus in the modeling of glacial discharge. This paper reviews the status of hydrological modeling in glacierized catchments of central Asia, discussing the limitations of the available models and extrapolating these to future challenges and directions. After reviewing recent efforts, we conclude that the main sources of uncertainty in assessing the regional hydrological impacts of climate change are the unreliable and incomplete data sets and the lack of understanding of the hydrological regimes of glacierized catchments of central Asia. Runoff trends indicate a complex response to changes in climate. For future variation of water resources, it is essential to quantify the responses of hydrologic processes to both climate change and shrinking glaciers in glacierized catchments, and scientific focus should be on reducing uncertainties linked to these processes.

  6. Topic: Catchment system dynamics: Processes and feedbacks

    NASA Astrophysics Data System (ADS)

    Keesstra, Saskia

    2015-04-01

    In this meeting we can talk about my main expertise: the focus of my research ocus revolves around understanding catchment system dynamics in a holistic way by incorporating both processes on hillslopes as well as in the river channel. Process knowledge enables explanation of the impact of natural and human drivers on the catchment systems and which consequences these drivers have for water and sediment connectivity. Improved understanding of the catchment sediment and water dynamics will empower sustainable land and river management and mitigate soil threats like erosion and off-side water and sediment accumulation with the help of nature's forces. To be able to understand the system dynamics of a catchment, you need to study the catchment system in a holistic way. In many studies only the hillslopes or even plots are studied; or only the channel. However, these systems are connected and should be evaluated together. When studying a catchment system any intervention to the system will create both on- as well as off sites effects, which should especially be taken into account when transferring science into policy regulations or management decisions.

  7. Sources and yields of dissolved carbon in northern Wisconsin stream catchments with differing amounts of Peatland

    USGS Publications Warehouse

    Elder, J.F.; Rybicki, N.B.; Carter, V.; Weintraub, V.

    2000-01-01

    In five tributary streams (four inflowing and one outflowing) of 1600-ha Trout Lake in northern Wisconsin, USA, we examined factors that can affect the magnitude of stream flow and transport of dissolved organic and inorganic carbon (DOC and DIC) through the streams to the lake. One catchment, the Allequash Creek basin, was investigated in more detail to describe the dynamics of carbon flow and to identify potential carbon sources. Stream flows and carbon loads showed little or no relation to surface-water catchment area. They were more closely related to ground-water watershed area because ground-water discharge, from both local and regional sources, is a major contributor to the hydrologic budgets of these catchments. An important factor in determining carbon influx to the stream is the area of peatland in the catchment. Peatland porewaters contain DOC concentrations up to 40 mg l-1 and are a significant potential carbon source. Ground-water discharge and lateral flow through peat are the suspected mechanisms for transport of that carbon to the streams. Carbon and nitrogen isotopes suggested that the sources of DOC in Allequash Creek above Allequash Lake were wetland vegetation and peat and that the sources below Allequash Lake were filamentous algae and wild rice. Catchments with high proportions of peatland, including the Allequash Creek catchment, tended to have elevated DOC loads in outflowing stream water. Respiration and carbon mineralization in lakes within the system tend to produce low DOC and low DOC/DIC in lake outflows, especially at Trout Lake. In Allequash Lake, however, the shallow peat island and vegetation-filled west end were sources of DOC. Despite the vast carbon reservoir in the peatlands, carbon yields were very low in these catchments. Maximum yields were on the order of 2.5 g m-2 y-1 DOC and 5.5 g m-2 y-1 DIC. The small yields were attributable to low stream flows due to lack of significant overland runoff and very limited stream channel

  8. A detailed model for simulation of catchment scale subsurface hydrologic processes

    NASA Technical Reports Server (NTRS)

    Paniconi, Claudio; Wood, Eric F.

    1993-01-01

    A catchment scale numerical model is developed based on the three-dimensional transient Richards equation describing fluid flow in variably saturated porous media. The model is designed to take advantage of digital elevation data bases and of information extracted from these data bases by topographic analysis. The practical application of the model is demonstrated in simulations of a small subcatchment of the Konza Prairie reserve near Manhattan, Kansas. In a preliminary investigation of computational issues related to model resolution, we obtain satisfactory numerical results using large aspect ratios, suggesting that horizontal grid dimensions may not be unreasonably constrained by the typically much smaller vertical length scale of a catchment and by vertical discretization requirements. Additional tests are needed to examine the effects of numerical constraints and parameter heterogeneity in determining acceptable grid aspect ratios. In other simulations we attempt to match the observed streamflow response of the catchment, and we point out the small contribution of the streamflow component to the overall water balance of the catchment.

  9. A detailed model for simulation of catchment scale subsurface hydrologic processes

    NASA Astrophysics Data System (ADS)

    Paniconi, Claudio; Wood, Eric F.

    1993-06-01

    A catchment scale numerical model is developed based on the three-dimensional transient Richards equation describing fluid flow in variably saturated porous media. The model is designed to take advantage of digital elevation data bases and of information extracted from these data bases by topographic analysis. The practical application of the model is demonstrated in simulations of a small subcatchment of the Konza Prairie reserve near Manhattan, Kansas. In a preliminary investigation of computational issues related to model resolution, we obtain satisfactory numerical results using large aspect ratios, suggesting that horizontal grid dimensions may not be unreasonably constrained by the typically much smaller vertical length scale of a catchment and by vertical discretization requirements. Additional tests are needed to examine the effects of numerical constraints and parameter heterogeneity in determining acceptable grid aspect ratios. In other simulations we attempt to match the observed streamflow response of the catchment, and we point out the small contribution of the streamflow component to the overall water balance of the catchment.

  10. Factors influencing water transit times in snowmelt-dominated, headwater catchments of the western U.S.

    NASA Astrophysics Data System (ADS)

    Clow, D. W.; Mast, A.

    2015-12-01

    In catchments, water transit times (TTs) refer to the elapsed time between entry of water at the ground surface and exit of water at the catchment outlet. Transit times are an important characteristic of catchments in that they reflect the time available for interaction between water, soil, and biota within the system. Thus, they exert a strong influence on hydrologic resilience to drought and climate change, and on the sensitivity of aquatic ecosystems to atmospheric pollutants. Transit times may vary spatially due to variations in basin characteristics, such as slope, size, and amount and type of soil and vegetation; however, the relative influence of these factors on TTs is poorly known. In this study, we estimate mean transit times (MTTs) for 11 snowmelt-dominated, headwater catchments in the western U.S. using the convolution integral approach, which relies on differences in the magnitude of seasonal variability in δ18O in precipitation and stream water to estimate MTTs. Seasonal variability in δ18O was calculated based on analyses of precipitation and stream water samples collected at weekly to monthly intervals. Results indicate that MTTs ranged from 0.6 to 2.1 years, and were positively influenced by percent of the catchment covered by forest (r2 = 0.56; p = 0.008), and negatively influenced by barren terrain (e.g., bedrock; r2 = 0.48; p = 0.019). MTTs showed a weak negative relation to mean basin slope (r2 = 0.31; p = 0.076) and no relation to basin size or elevation. These results illustrate the importance of soil as a key factor influencing MTTs, with basin slope acting as a secondary influence. Heavily forested basins tend to have deep, well-developed soils with substantial water storage capacity; these soils help maintain baseflow during drought conditions, providing hydrologic resilience to the system, and they are an important location for geochemical and biological processes that neutralize acidity and assimilate atmospherically deposited nitrogen

  11. Transit time estimation using tritium and stable isotopes in a Mediterranean mountain catchment

    NASA Astrophysics Data System (ADS)

    Roig-Planasdemunt, Maria; Stewart, Mike; Latron, Jérôme; Llorens, Pilar; Morgenstern, Uwe

    2015-04-01

    Water resources of Mediterranean regions mainly depend on runoff generated in mountain areas. Therefore, study of the time water spends travelling through Mediterranean mountains is important for water resources management as it reflects the ability of catchments to retain and release water. Natural isotopes (tritium and stable isotopes) have been used in different environments to quantify the ages of water within catchments. However, there are relatively few studies of water transit times in Mediterranean mountain regions. Additionally, tritium dating is more common in Southern Hemisphere streams because they were less affected by tritium produced mainly in the North Hemisphere by nuclear weapons testing in the 1950s and 60s. With the aim of improving knowledge of the hydrological catchment functioning of Mediterranean mountain areas, this work estimates water transit times in spring water, groundwater and stream water using tritium and stable isotope (δ18O and δ2H) measurements in the Vallcebre Research Catchments (NE Spain, 42° 12'N, 1° 49'E). Tritium measurements from a previous study carried out in 1996-1998 (Herrmann et al., 1999) were supplemented by new samples collected on 3 November 2013. Difficulties with the age interpretation of the tritium measurements arise from the determination of the tritium input function, the different accuracies of the tritium measurements and the ambiguous ages resulting from past input of tritium from nuclear testing to the atmosphere. Water stable isotope samples were collected in rainfall, spring water, groundwater and streamwater at baseflow conditions every 15 days over a 27 month period. Detailed distributed hydrometric measurements (precipitation, potential evapotranspiration, discharge and water table level) were obtained during the same period. Preliminary results using δ18O, δ2H and tritium show that mean transit times in the Cal Rodó catchment (4.2 km2) ranged between 1.3 and 11.6 years. The lowest mean

  12. Efforts to Unravel the Cause of Shrinkage of Lake Chad: Development of Hydrologic Real-time Observatory Network in the Lake Chad Basin

    NASA Astrophysics Data System (ADS)

    Lee, J.; Ichoku, C. M.; Bolten, J. D.; Policelli, F. S.; Djimadoumngar, K. N.; Abdullahi, S. I.; Bila, M. D.; Djoret, D.; Ibrahim, G.; Selker, J. S.; Hochreutener, R.; Annor, F. O.

    2015-12-01

    Lake Chad, the fourth largest lake in Africa, is well known as a shrinking lake due to adverse impact of climate change and increased population during drought periods in the 1980s and 1990s. While the shrinkage of the Lake has been studied broadly using remote sensing data, the main cause of shrinkage is still uncertain due to limited availability of ground-truth data. Lack of infrastructure, insecure site conditions, vandalism, and limited site accessibility make it difficult to establish a real-time monitoring network in many parts of Africa including the Lake Chad Basin. For a better understanding of how the Lake responds to the change of weather patterns and other hydrologic processes such as runoff, groundwater flow, and evapotranspiration, a real-time monitoring network is essential in the region. In early 2015, a team from NASA, the Lake Chad Basin Commission, and the University of Missouri - Kansas City set up a hydrologic real-time observatory network in the Chari-Logone catchment, the main feeder of water to the Lake, to monitor meteorological conditions, soil moisture, and groundwater. The TAHMO (Trans-African Hydro-Meteorological Observatory) weather stations were adopted to monitor rainfall, relative humidity, solar radiation, wind speed, and temperature. The present study shows preliminary analysis of the correlations between meteorological and hydrological parameters from real-time monitoring data in the Chari-Logone catchment. We also discuss the importance of partnership with local government and community involvement for data collection and share for sustainable hydrological research in the Lake Chad Basin.

  13. Model‐based analysis of the influence of catchment properties on hydrologic partitioning across five mountain headwater subcatchments

    PubMed Central

    Wagener, Thorsten; McGlynn, Brian

    2015-01-01

    Abstract Ungauged headwater basins are an abundant part of the river network, but dominant influences on headwater hydrologic response remain difficult to predict. To address this gap, we investigated the ability of a physically based watershed model (the Distributed Hydrology‐Soil‐Vegetation Model) to represent controls on metrics of hydrologic partitioning across five adjacent headwater subcatchments. The five study subcatchments, located in Tenderfoot Creek Experimental Forest in central Montana, have similar climate but variable topography and vegetation distribution. This facilitated a comparative hydrology approach to interpret how parameters that influence partitioning, detected via global sensitivity analysis, differ across catchments. Model parameters were constrained a priori using existing regional information and expert knowledge. Influential parameters were compared to perceptions of catchment functioning and its variability across subcatchments. Despite between‐catchment differences in topography and vegetation, hydrologic partitioning across all metrics and all subcatchments was sensitive to a similar subset of snow, vegetation, and soil parameters. Results also highlighted one subcatchment with low certainty in parameter sensitivity, indicating that the model poorly represented some complexities in this subcatchment likely because an important process is missing or poorly characterized in the mechanistic model. For use in other basins, this method can assess parameter sensitivities as a function of the specific ungauged system to which it is applied. Overall, this approach can be employed to identify dominant modeled controls on catchment response and their agreement with system understanding. PMID:27642197

  14. An Open-Source Approach for Catchment's Physiographic Characterization

    NASA Astrophysics Data System (ADS)

    Di Leo, M.; Di Stefano, M.

    2013-12-01

    A water catchment's hydrologic response is intimately linked to its morphological shape, which is a signature on the landscape of the particular climate conditions that generated the hydrographic basin over time. Furthermore, geomorphologic structures influence hydrologic regimes and land cover (vegetation). For these reasons, a basin's characterization is a fundamental element in hydrological studies. Physiographic descriptors have been extracted manually for long time, but currently Geographic Information System (GIS) tools ease such task by offering a powerful instrument for hydrologists to save time and improve accuracy of result. Here we present a program combining the flexibility of the Python programming language with the reliability of GRASS GIS, which automatically performing the catchment's physiographic characterization. GRASS (Geographic Resource Analysis Support System) is a Free and Open Source GIS, that today can look back on 30 years of successful development in geospatial data management and analysis, image processing, graphics and maps production, spatial modeling and visualization. The recent development of new hydrologic tools, coupled with the tremendous boost in the existing flow routing algorithms, reduced the computational time and made GRASS a complete toolset for hydrological analysis even for large datasets. The tool presented here is a module called r.basin, based on GRASS' traditional nomenclature, where the "r" stands for "raster", and it is available for GRASS version 6.x and more recently for GRASS 7. As input it uses a Digital Elevation Model and the coordinates of the outlet, and, powered by the recently developed r.stream.* hydrological tools, it performs the flow calculation, delimits the basin's boundaries and extracts the drainage network, returning the flow direction and accumulation, the distance to outlet and the hill slopes length maps. Based on those maps, it calculates hydrologically meaningful shape factors and

  15. Catchment biophysical drivers of streamflow characteristics

    NASA Astrophysics Data System (ADS)

    Trancoso, R.

    2015-12-01

    The characteristics of streamflow reflect the co-evolution of climate, soils, topography and vegetation of catchments. Hydrological metrics or signatures can represent the long-term behaviour and integrate the influence of all the streamflow drivers. Although this sort of relationship has been developed in regional studies exploring prediction of Flow Duration Curves and other streamflow metrics, little is known about the controls of other key streamflow characteristics especially in continent scale. This study aims to understand how catchment biophysical variables control key hydrological metrics such as baseflow index, elasticity of streamflow to rainfall variability and intermittency in continent scale and regionally. We used a set of catchment biophysical variables to model key streamflow signatures using multivariate power-law and beta regressions in 355 catchments located along the eastern Australian seaboard. Streamflow signatures were derived from daily streamflow time series data from 1980 to 2013. We tested 52 catchment biophysical characteristics related to climate, soil, topography, geography, geomorphology, vegetation and land-cover as predictors of the streamflow signatures. The prediction R-squared ranged from 63 to 72% when relationships are built in continent scale, but can be greater than 80% when regressions are regionalised. The interpretation of the modelled relationships offers new insights regarding the controls of flow characteristics.

  16. What makes catchment management groups "tick"?

    PubMed

    Oliver, P

    2001-01-01

    The work of catchment management groups throughout Australia represents a significant economic and social investment in natural resource management. Institutional structures and policies, the role of on-ground coordinators, facilitation processes, citizen participation and social capital are critical factors influencing the success of catchment management groups. From a participant-researcher viewpoint, this paper signposts research directions and themes that are being pursued from the participant/coordinator, catchment group, and lead government/non-government agency perspective on the influence of these factors on the success of a catchment management group in the Pumicestone Region of Southeast Queensland, Australia. Research directions, themes and discussion/reflection points for practitioners include--the importance of understanding milieu; motivation; success; having fun; "networking networks"; involvement of "nontraditional" stakeholders; development of stakeholder/participant partnerships; learning from other practitioners; methods of stakeholder/participant representation; evaluation; the need for guiding principles or philosophy; the equivalence of planning, implementation, evaluation, and resourcing; catchments as fundamental units of Nature; continuity of support for groups; recognising a new role for government; working with existing networks; and the need for an eclectic approach to natural resource management.

  17. Controls on old and new water contributions to stream flow at some nested catchments in Vermont, USA

    USGS Publications Warehouse

    Shanley, J.B.; Kendall, C.; Smith, T.E.; Wolock, D.M.; McDonnell, Jeffery J.

    2002-01-01

    Factors controlling the partitioning of old and new water contributions to stream flow were investigated for three events in four catchments (three of which were nested) at Sleepers River Research Watershed in Danville, Vermont. In the 1993 snowmelt period, two-component isotopic hydrograph separations showed that new water (meltwater) inputs to the stream ranged widely from 41 to 74%, and increased with catchment size (41 to 11 125 ha) (with one exception) and with open land cover (0-73%). Peak dissolved organic carbon concentrations and relative alkalinity dilution in stream water ranked in the same order among catchments as the new water fractions, suggesting that new water followed shallow flow paths. During the 1994 snowmelt, despite similar timing and magnitude of melt inputs, the new-water contribution to stream flow ranged only from 30 to 36% in the four catchments. We conclude that the uncommonly high and variable new water fractions in streamwater during the 1993 melt were caused by direct runoff of meltwater over frozen ground, which was prevalent in open land areas during the 1993 winter. In a high-intensity summer rainstorm in 1993, new water fractions were smaller relative to the 1993 snowmelt, ranging from 28 to 46%, but they ranked in the identical catchment order. Reconciliation of the contrasting patterns of new-old water partitioning in the three events appears to require an explanation that invokes multiple processes and effects, including: 1 topographically controlled increase in surface-saturated area with increasing catchment size; 2 direct runoff over frozen ground; 3 low infiltration in agriculturally compacted soils; 4 differences in soil transmissivity, which may be more relevant under dry antecedent conditions. These data highlight some of the difficulties faced by catchment hydrologists in formulating a theory of runoff generation at varying basin scales. Copyright ?? 2002 John Wiley and Sons, Ltd.

  18. Erosivity, surface runoff, and soil erosion estimation using GIS-coupled runoff-erosion model in the Mamuaba catchment, Brazil.

    PubMed

    Marques da Silva, Richarde; Guimarães Santos, Celso Augusto; Carneiro de Lima Silva, Valeriano; Pereira e Silva, Leonardo

    2013-11-01

    This study evaluates erosivity, surface runoff generation, and soil erosion rates for Mamuaba catchment, sub-catchment of Gramame River basin (Brazil) by using the ArcView Soil and Water Assessment Tool (AvSWAT) model. Calibration and validation of the model was performed on monthly basis, and it could simulate surface runoff and soil erosion to a good level of accuracy. Daily rainfall data between 1969 and 1989 from six rain gauges were used, and the monthly rainfall erosivity of each station was computed for all the studied years. In order to evaluate the calibration and validation of the model, monthly runoff data between January 1978 and April 1982 from one runoff gauge were used as well. The estimated soil loss rates were also realistic when compared to what can be observed in the field and to results from previous studies around of catchment. The long-term average soil loss was estimated at 9.4 t ha(-1) year(-1); most of the area of the catchment (60%) was predicted to suffer from a low- to moderate-erosion risk (<6 t ha(-1) year(-1)) and, in 20% of the catchment, the soil erosion was estimated to exceed > 12 t ha(-1) year(-1). Expectedly, estimated soil loss was significantly correlated with measured rainfall and simulated surface runoff. Based on the estimated soil loss rates, the catchment was divided into four priority categories (low, moderate, high and very high) for conservation intervention. The study demonstrates that the AvSWAT model provides a useful tool for soil erosion assessment from catchments and facilitates the planning for a sustainable land management in northeastern Brazil.

  19. Coupling a basin erosion and river sediment transport model into a large scale hydrological model: an application in the Amazon basin

    NASA Astrophysics Data System (ADS)

    Buarque, D. C.; Collischonn, W.; Paiva, R. C. D.

    2012-04-01

    This study presents the first application and preliminary results of the large scale hydrodynamic/hydrological model MGB-IPH with a new module to predict the spatial distribution of the basin erosion and river sediment transport in a daily time step. The MGB-IPH is a large-scale, distributed and process based hydrological model that uses a catchment based discretization and the Hydrological Response Units (HRU) approach. It uses physical based equations to simulate the hydrological processes, such as the Penman Monteith model for evapotranspiration, and uses the Muskingum Cunge approach and a full 1D hydrodynamic model for river routing; including backwater effects and seasonal flooding. The sediment module of the MGB-IPH model is divided into two components: 1) prediction of erosion over the basin and sediment yield to river network; 2) sediment transport along the river channels. Both MGB-IPH and the sediment module use GIS tools to display relevant maps and to extract parameters from SRTM DEM (a 15" resolution was adopted). Using the catchment discretization the sediment module applies the Modified Universal Soil Loss Equation to predict soil loss from each HRU considering three sediment classes defined according to the soil texture: sand, silt and clay. The effects of topography on soil erosion are estimated by a two-dimensional slope length (LS) factor which using the contributing area approach and a local slope steepness (S), both estimated for each DEM pixel using GIS algorithms. The amount of sediment releasing to the catchment river reach in each day is calculated using a linear reservoir. Once the sediment reaches the river they are transported into the river channel using an advection equation for silt and clay and a sediment continuity equation for sand. A sediment balance based on the Yang sediment transport capacity, allowing to compute the amount of erosion and deposition along the rivers, is performed for sand particles as bed load, whilst no

  20. Hydrograph transposition to ungauged basin accounting for spatio-temporal rainfall variability

    NASA Astrophysics Data System (ADS)

    de Lavenne, Alban; Cudennec, Christophe

    2013-04-01

    Lack of measurements is one of the main issues in hydrological modelling. However, neighbours and nested gauged catchment are precious sources of information to understand the catchment behaviours within one region. Extracting the maximum of information from those points of measurements, that could be then transposed to ungauged catchment, is still a great challenge. We propose a methodology to transpose hydrological information from gauged catchments to ungauged ones, in order to simulate streamflow hydrographs. It uses geomorphology-based hydrological modelling, which is particularly well adapted to ungauged basins thanks to its robustness, generality and flexibility. We develop a geomorphology-based model on the gauged catchment which has been built in order to capture the main behaviour of the basin. Its transfer function considers the different dynamics of the catchment through the combination of velocities and width functions. Moreover, the explicit structure of the model enables to easily create a map of isochrone areas describing the time to the outlet. Therefore, spatially distributed rainfall can then be split into those isochrone areas, permitting the transfer function to deal with spatio-temporal variability of rainfall. Once the model calibrated, using a particle swarm optimisation algorithm, its transfer function is inversed to assess the net rainfall time series. In this way, we obtained a standardized variable which is used to estimate discharge in ungauged basin. Therefore, net rainfall time series is transposed and convoluted on the ungauged catchment using its own transfer function. Spatio-temporal rainfall variability between basins is considered through a correction of this net rainfall time series. This correction is based on differences between mean gross rainfall observation among those two catchments. This methodology is applied on pairs of basins among 6 gauged basins (from 5km² to 316km²) located in Brittany, France. For the benefit of

  1. What can we learn from the hydrological modeling of small-scale catchments for the discharge and water balance modeling of mesoscale catchments?

    NASA Astrophysics Data System (ADS)

    Cornelissen, Thomas; Diekkrüger, Bernd; Bogena, Heye

    2015-04-01

    The application of 3D hydrological models remains a challenge both in research and application studies because the parameterization not only depends on the amount and quality of data available for calibration and validation but also on the spatial and temporal model resolution. In recent years, the model parameterization has improved with the availability of high resolution data (e.g. eddy-covariance, wireless soil sensor networks). Unfortunately, these high resolution data are typically only available for small scale research test sites. This study aims to upscale the parameterization from a highly equipped, small-scale catchment to a mesoscale catchment in order to reduce the parameterization uncertainty at that scale. The two nested catchments chosen for the study are the 0.38 km² large spruce covered Wüstebach catchment and the 42 km² large Erkensruhr catchment characterized by a mixture of spruce and beech forest and grassland vegetation. The 3D hydrogeological model HydroGeoSphere (HGS) has already been setup for the Wüstebach catchment in a previous study with a focus on the simulation performance of soil water dynamics and patterns. Thus, the parameterization process did not only optimize the water balance components but the catchment's wireless soil sensor network data were utilized to calibrate porosities in order to improve the simulation of soil moisture dynamics. In this study we compared different HGS model realizations for the Erkensruhr catchment with different input data. For the first model realization, the catchment is treated heterogeneous in terms of soil properties and topography but homogeneous with respect to land use, precipitation and potential evapotranspiration. For this case, the spruce forest parameterization and the climate input data were taken directly from the small-scale Wüstebach model realization. Next, the calibrated soil porosity for the Wüstebach catchment is applied to the Erkensruhr. Further model realizations

  2. In Lieu of the Paired-Catchment Approach - Hydrologic Model Change Detection at the Catchment Scale

    NASA Astrophysics Data System (ADS)

    Zegre, N. P.

    2009-05-01

    Knowledge of the effects of forest management on hydrology primarily comes from paired-catchment studies conducted world-wide. While this approach has been useful for discerning changes in small experimental catchments and has contributed fundamental knowledge of the effects of forest and natural resources management on hydrology, results from experimental catchment studies exhibit temporal variability, have limited spatial inference, and lack insight into internal catchment processes. To address these limitations, traditional field experiments can be supplemented with numerical models to isolate the effects of disturbance on catchment behavior. Outlined in this study is an alternative method of change detection for daily time-series streamflow that integrates hydrologic modeling and statistical change detection methods used to discern the effects of contemporary forest management on the hydrology of western Oregon Cascades headwater catchments. In this study, a simple rainfall-runoff model was used to generate virtual reference catchments using attributes that reflect streamflow conditions absent of forest disturbance. Streamflow was simulated under three levels of model uncertainty using GLUE and were used to construct generalized least squares regression models to discern changes in hydrologic behavior. By considering processes within a single experimental catchment rather than the two spatially explicit catchments used in traditional paired experiments, it was possible to reduce unexplained variation and increase the likelihood of correctly detecting hydrologic effects following forest harvesting. In order to evaluate the stability of the hydrologic and statistical models and catchment behavior over time, the change detection method was applied to a contemporary reference catchment. By applying the change detection model to reference catchments, it was possible to eliminate unexpected variation as a cause for detected changes in observed hydrology. Further, it

  3. Response of paleofloods to climate variability in alpine catchments of different size reconstructed from floodplain sediments. Similarities or differences?

    NASA Astrophysics Data System (ADS)

    Schulte, Lothar; Carvalho, Filipe; Llorca, Jaime; Monterrubio, Glòria; Peña, Juan Carlos; Cabrera-Medina, Paula; Gómez-Bolea, Antonio; Sánchez-García, Carlos

    2016-04-01

    Continuous palaeohydrological time series are generally attributed to lake sediments rather than to those of fluvial sediments. However, most of the alpine lakes analysed are fed by small catchments (few km2). Recent studies show the high potential of flood reconstruction form sedimentary floodplain proxies of mid-size catchments (hundreds of km2) when calibrated by historical sources or other markers. Despite of different catchment sizes, flood pulses achieved from lake and flood plain sediments coincides in some cases. Nevertheless, these correlations must not be taken for granted, because catchment response can be strongly influenced by local physiographic and climatic parameters such as the unequal spatial distribution of precipitation caused by summer thunderstorms and advective rainfall events. To contribute to this discussion, our study investigate new proxy data of three cores retrieved from a small basin in the Bernese Alps, fed by the alluvial fans of Eistlenbach (4 km2) and Farnigraben (2 km2) which were compared with the floodplain records from the nearby Aare (596 km2) and Lütschine (379 km2) catchments. Following the same methodology developed previously in the other alpine basins, a 3200-yr long flood series were reconstructed from sedimentary and geochemical data applying XRF-core scan techniques, conventional XRF, LOI and grain size analysis. Flood pulses were identified by 30 flood layers, and a higher number of Zr/Ti, Sr/Ti, Ca/Ti peaks and Factor 1 scores. Modern flood signals were calibrated by historical sources, maps, aerial photographs and instrumental data. Not all events were recorded by coarse-grained beds because of the spatial variations of alluvial fan channels and their connectivity to the small distal basin. Recurrence intervals of the tipping points of the fan channel oscillation are traced by key changes of sedimentation rates and facies. However, geochemical proxies correlate not only very close with the historical local data

  4. Estimating catchment-scale groundwater dynamics from recession analysis - enhanced constraining of hydrological models

    NASA Astrophysics Data System (ADS)

    Skaugen, Thomas; Mengistu, Zelalem

    2016-12-01

    In this study, we propose a new formulation of subsurface water storage dynamics for use in rainfall-runoff models. Under the assumption of a strong relationship between storage and runoff, the temporal distribution of catchment-scale storage is considered to have the same shape as the distribution of observed recessions (measured as the difference between the log of runoff values). The mean subsurface storage is estimated as the storage at steady state, where moisture input equals the mean annual runoff. An important contribution of the new formulation is that its parameters are derived directly from observed recession data and the mean annual runoff. The parameters are hence estimated prior to model calibration against runoff. The new storage routine is implemented in the parameter parsimonious distance distribution dynamics (DDD) model and has been tested for 73 catchments in Norway of varying size, mean elevation and landscape type. Runoff simulations for the 73 catchments from two model structures (DDD with calibrated subsurface storage and DDD with the new estimated subsurface storage) were compared. Little loss in precision of runoff simulations was found using the new estimated storage routine. For the 73 catchments, an average of the Nash-Sutcliffe efficiency criterion of 0.73 was obtained using the new estimated storage routine compared with 0.75 using calibrated storage routine. The average Kling-Gupta efficiency criterion was 0.80 and 0.81 for the new and old storage routine, respectively. Runoff recessions are more realistically modelled using the new approach since the root mean square error between the mean of observed and simulated recession characteristics was reduced by almost 50 % using the new storage routine. The parameters of the proposed storage routine are found to be significantly correlated to catchment characteristics, which is potentially useful for predictions in ungauged basins.

  5. Estimating gully erosion contribution to large catchment sediment yield rate in Tanzania

    NASA Astrophysics Data System (ADS)

    Ndomba, Preksedis Marco; Mtalo, Felix; Killingtveit, Aanund

    The objective of this paper is to report on the issues and proposed approaches in estimating the contribution of gully erosion to sediment yield at large catchment. The case study is the upstream of Pangani River Basin (PRB) located in the North Eastern part of Tanzania. Little has been done by other researchers to study and/or extrapolate gully erosion results from plot or field scale to large catchment. In this study multi-temporal aerial photos at selected sampling sites were used to estimate gully size and morphology changes over time. The laboratory aerial photo interpretation results were groundtruthed. A data mining tool, Cubist, was used to develop predictive gully density stepwise regression models using aerial photos and environment variables. The delivery ratio was applied to estimate the sediment yield rate. The spatial variations of gully density were mapped under Arc View GIS Environment. Gully erosion sediment yield contribution was estimated as a ratio between gully erosion sediment yield and total sediment yield at the catchment outlet. The general observation is that gullies are localized features and not continuous spatially and mostly located on some mountains’ foot slopes. The estimated sediment yield rate from gullies erosion is 6800 t/year, which is about 1.6% of the long-term total catchment sediment yield rate. The result is comparable to other study findings in the same catchment. In order to improve the result larger scale aerial photos and high resolution spatial data on soil-textural class and saturated hydraulic conductivity - are recommended.

  6. Multiple colonisations of the Lake Malawi catchment by the genus Opsaridium (Teleostei: Cyprinidae).

    PubMed

    Sungani, Harold; Ngatunga, Benjamin P; Koblmüller, Stephan; Mäkinen, Tuuli; Skelton, Paul H; Genner, Martin J

    2017-02-01

    It has been proposed that the fish faunas of African rivers assemble through multiple colonisation events, while lake faunas form additionally through intralacustine speciation. While this pattern has been established for many lineages, most notably cichlids, there are opportunities to further investigate the concept using phylogenies of congeneric endemic species within ancient lake catchments. The Lake Malawi catchment contains three river-spawning cyprinids of the genus Opsaridium, two of which are endemic. These species differ in body size, migratory behaviour and habitat use, but it has never previously been tested if these represent a monophyletic radiation, or have instead colonised the lake independently. We placed these species in a broader phylogeny of Opsaridium and the related genus Raiamas, including all known species from the river systems surrounding Lake Malawi. Our results suggest that each of the species has independently colonised the lake catchment, with all three taxa having well-defined sister taxa outside of the lake, and all sharing a common ancestor ∼14.9million years ago, before the Lake Malawi basin started to form ∼8.6million years ago. Additionally, the results strongly support previous observations that Opsaridium is not a monophyletic group, but instead contains Raiamas from the Congo drainage. Together these results are supportive of the concept that river fish faunas within African catchments are primarily assembled through a process of accumulation from independent origins, rather than within-catchment speciation and adaptive radiation. In light of these results we also suggest there is scope for a re-evaluation of systematics of both Opsaridium and Raiamas.

  7. Diffuse nutrient losses and the impact factors determining their regional differences in four catchments from North to South China

    NASA Astrophysics Data System (ADS)

    Zhang, Yongyong; Zhou, Yujian; Shao, Quanxi; Liu, Hongbin; Lei, Qiuliang; Zhai, Xiaoyan; Wang, Xuelei

    2016-12-01

    Diffuse nutrient loss mechanism is complicated and shows remarkably regional differences due to spatial heterogeneities of underlying surface conditions, climate and agricultural practices. Moreover, current available observations are still hard to support the identification of impact factors due to different time or space steps. In this study, an integrated water system model (HEQM) was adopted to obtain the simulated loads of diffuse components (carriers: runoff and sediment; nutrient: total nitrogen (TN) and total phosphorous (TP)) with synchronous scales. Multivariable statistical analysis approaches (Analysis of Similarity and redundancy analysis) were used to assess the regional differences, and to identify impact factors as well as their contributions. Four catchments were selected as our study areas, i.e., Xiahui and Zhangjiafen Catchments of Miyun Basin in North China, Yuliang and Tunxi Catchments of Xin'anjiang Basin in South China. Results showed that the model performances of monthly processes were very good for runoff and good for sediment, TN and TP. The annual average coefficients of all the diffuse components in Xin'anjiang Basin were much greater than those in Miyun Basin, and showed significantly regional differences. All the selected impact factors interpreted 72.87-82.16% of the regional differences of carriers, and 62.72-71.62% of those of nutrient coefficients, respectively. For individual impact factor categories, the critical category was geography, followed by land-use/cover, carriers, climate, as well as soil and agricultural practices in Miyun Basin, or agricultural practices and soil in Xin'anjiang Basin. For individual factors, the critical factors were locations for the carrier regional differences, and carriers or chemical fertilizer for the nutrient regional differences. This study is expected to promote further applications of integrated water system model and multivariable statistical analysis in the diffuse nutrient studies, and

  8. Human impacts on river water quality- comparative research in the catchment areas of the Tone River and the Mur River-

    NASA Astrophysics Data System (ADS)

    Kogure, K.

    2013-12-01

    Human activities in river basin affect river water quality as water discharges into river with pollutant after we use it. By detecting pollutants source, pathway, and influential factor of human activities, it will be possible to consider proper river basin management. In this study, material flow analysis was done first and then nutrient emission modeling by MONERIS was conducted. So as to clarify land use contribution and climate condition, comparison of Japanese and European river basin area has been made. The model MONERIS (MOdelling Nutrient Emissions in RIver Systems; Behrendt et al., 2000) was applied to estimate the nutrient emissions in the Danube river basin by point sources and various diffuse pathways. Work for the Mur River Basin in Austria was already carried out by the Institute of Water Quality, Resources and Waste Management at the Vienna University of Technology. This study treats data collection, modelling for the Tone River in Japan, and comparative analysis for these two river basins. The estimation of the nutrient emissions was carried out for 11 different sub catchment areas covering the Tone River Basin for the time period 2000 to 2006. TN emissions into the Tone river basin were 51 kt/y. 67% was via ground water and dominant for all sub catchments. Urban area was also important emission pathway. Human effect is observed in urban structure and agricultural activity. Water supply and sewer system make urban water cycle with pipeline structure. Excess evapotranspiration in arable land is also influential in water cycle. As share of arable land is 37% and there provides agricultural products, it is thought that N emission from agricultural activity is main pollution source. Assumption case of 10% N surplus was simulated and the result was 99% identical to the actual. Even though N surplus reduction does not show drastic impact on N emission, it is of importance to reduce excess of fertilization and to encourage effective agricultural activity

  9. A simple hydrologic model for rapid prediction of runoff from ungauged coastal catchments

    NASA Astrophysics Data System (ADS)

    Wan, Yongshan; Konyha, Kenneth

    2015-09-01

    We developed a lumped conceptual rainfall-runoff model for rapid prediction of runoff generated in the unique hydrological setting with flat terrain, sandy soils, high groundwater table, and a dense drainage canal network in south Florida. The model is conceptualized as rainfall and evapotranspiration filling and emptying the root zone and excess rainfall recharging three storage zones. Outflows from these storage zones, routed with parallel arrangement of three linear reservoirs, represent different flow components of catchment runoff, i.e., slow drainage (shallow subsurface flow), medium drainage (interflow and saturation excess overland flow), and fast drainage (direct runoff from impervious urban areas or from water table management in agricultural land). The model is parsimonious with eight model parameters along with two optional water management parameters. A regionalization study was conducted through model parameterization to achieve target hydrological behavior of typical land uses, which are the most significant basin descriptor affecting catchment hydrology in south Florida. Cross validation with 16 gauged basins dominated by urban, agricultural, and natural lands, respectively, indicated that the model provides an effective tool for rapid prediction of runoff in ungauged basins using the regionalized model parameters. A case study is presented, involving application of the model to support real-time adaptive management to hydrological operations for protection of estuarine ecosystems.

  10. Understanding Polycyclic Aromatic Hydrocarbon transfers at the catchment scale combining chemical and fallout radionuclides analyses

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    Contamination of river water and sediment constitutes a major environmental issue for industrialized countries. Polycyclic Aromatic Hydrocarbons (PAHs) are a group of persistent organic pollutants characterized by two or more fused rings. In recent years, studies dealing with PAHs have grown in number. Some PAHs present indeed a high risk for environment and human health because of their carcinogenic and mutagenic properties. However, most of these studies focused on measuring PAH concentration in the different compartments of the environment (air, soil, sediment, water, etc.) In this context, there remains a lack of understanding regarding the various processes responsible for PAH transfers from one environmental compartment to another. Our study aims to quantify PAHs transfers at the catchment scale by combining chemical analysis with gamma spectrometry. Air, soil, river water and sediment samples (n=820) were collected in two upstream sub-catchments of the Seine River basin (France) during one year. Chemical analyses were carried out to determine PAHs concentrations in all samples. Furthermore, measurement of fallout radionuclides (Beryllium-7, Lead-210, Caesium-137) in both rainfall and river sediment provided a way to discriminate between freshly eroded sediment vs. resuspension of older material that previously deposited on the riverbed. This information is crucial to estimate PAH residence time and transfer velocities in the Seine River basin. The results show that the PAH behaviour varies from one subcatchment to the next. PAH transfers depend indeed on both the characteristics of the catchment (e.g. topography, presence of drained cropland in catchments) and the local anthropogenic pressures. A significant increase in atmospheric deposition of PAHs is observed during winter due to a larger number of sources (household heating). The 14-month study has also highlighted the seasonal variations of PAH fluxes, which are mainly related to the hydrological

  11. Before and after integrated catchment management in a headwater catchment: changes in water quality.

    PubMed

    Hughes, Andrew O; Quinn, John M

    2014-12-01

    Few studies have comprehensively measured the effect on water quality of catchment rehabilitation measures in comparison with baseline conditions. Here we have analyzed water clarity and nutrient concentrations and loads for a 13-year period in a headwater catchment within the western Waikato region, New Zealand. For the first 6 years, the entire catchment was used for hill-country cattle and sheep grazing. An integrated catchment management plan was implemented whereby cattle were excluded from riparian areas, the most degraded land was planted in Pinus radiata, channel banks were planted with poplar trees and the beef cattle enterprise was modified. The removal of cattle from riparian areas without additional riparian planting had a positive and rapid effect on stream water clarity. In contrast, the water clarity decreased in those sub-catchments where livestock was excluded but riparian areas were planted with trees and shrubs. We attribute the decrease in water clarity to a reduction in groundcover vegetation that armors stream banks against preparatory erosion processes. Increases in concentrations of forms of P and N were recorded. These increases were attributed to: (i) the reduction of instream nutrient uptake by macrophytes and periphyton due to increased riparian shading; (ii) uncontrolled growth of a nitrogen fixing weed (gorse) in some parts of the catchment, and (iii) the reduction in the nutrient attenuation capacity of seepage wetlands due to the decrease in their areal coverage in response to afforestation. Our findings highlight the complex nature of the water quality response to catchment rehabilitation measures.

  12. Before and After Integrated Catchment Management in a Headwater Catchment: Changes in Water Quality

    NASA Astrophysics Data System (ADS)

    Hughes, Andrew O.; Quinn, John M.

    2014-12-01

    Few studies have comprehensively measured the effect on water quality of catchment rehabilitation measures in comparison with baseline conditions. Here we have analyzed water clarity and nutrient concentrations and loads for a 13-year period in a headwater catchment within the western Waikato region, New Zealand. For the first 6 years, the entire catchment was used for hill-country cattle and sheep grazing. An integrated catchment management plan was implemented whereby cattle were excluded from riparian areas, the most degraded land was planted in Pinus radiata, channel banks were planted with poplar trees and the beef cattle enterprise was modified. The removal of cattle from riparian areas without additional riparian planting had a positive and rapid effect on stream water clarity. In contrast, the water clarity decreased in those sub-catchments where livestock was excluded but riparian areas were planted with trees and shrubs. We attribute the decrease in water clarity to a reduction in groundcover vegetation that armors stream banks against preparatory erosion processes. Increases in concentrations of forms of P and N were recorded. These increases were attributed to: (i) the reduction of instream nutrient uptake by macrophytes and periphyton due to increased riparian shading; (ii) uncontrolled growth of a nitrogen fixing weed (gorse) in some parts of the catchment, and (iii) the reduction in the nutrient attenuation capacity of seepage wetlands due to the decrease in their areal coverage in response to afforestation. Our findings highlight the complex nature of the water quality response to catchment rehabilitation measures.

  13. Catchment scale multi-objective flood management

    NASA Astrophysics Data System (ADS)

    Rose, Steve; Worrall, Peter; Rosolova, Zdenka; Hammond, Gene

    2010-05-01

    Rural land management is known to affect both the generation and propagation of flooding at the local scale, but there is still a general lack of good evidence that this impact is still significant at the larger catchment scale given the complexity of physical interactions and climatic variability taking place at this level. The National Trust, in partnership with the Environment Agency, are managing an innovative project on the Holnicote Estate in south west England to demonstrate the benefits of using good rural land management practices to reduce flood risk at the both the catchment and sub-catchment scales. The Holnicote Estate is owned by the National Trust and comprises about 5,000 hectares of land, from the uplands of Exmoor to the sea, incorporating most of the catchments of the river Horner and Aller Water. There are nearly 100 houses across three villages that are at risk from flooding which could potentially benefit from changes in land management practices in the surrounding catchment providing a more sustainable flood attenuation function. In addition to the contribution being made to flood risk management there are a range of other ecosystems services that will be enhanced through these targeted land management changes. Alterations in land management will create new opportunities for wildlife and habitats and help to improve the local surface water quality. Such improvements will not only create additional wildlife resources locally but also serve the landscape response to climate change effects by creating and enhancing wildlife networks within the region. Land management changes will also restore and sustain landscape heritage resources and provide opportunities for amenity, recreation and tourism. The project delivery team is working with the National Trust from source to sea across the entire Holnicote Estate, to identify and subsequently implement suitable land management techniques to manage local flood risk within the catchments. These

  14. Seasonal variability of suspended sediment transport in the Seine river catchment area (France)

    NASA Astrophysics Data System (ADS)

    Franke, Christine; Baati, Selma; Ayrault, Sophie; Bonte, Philippe; Evrard, Olivier; Kissel, Catherine

    2010-05-01

    This study consists in an innovative application of environmental physico-chemical techniques on fluvial sediments with the aim to trace the seasonal changes in suspended sediment transport of the complex Seine river catchment area in northern France. The aim of this project is to develop a detailed understanding for the discrimination of naturally triggered and anthropogenic induced processes and their temporal changes with weather conditions. With a focus on the heavy metal fraction, we determine the regional distribution of the suspended material and search for environmental fingerprints demonstrating the influence of fluvial transport mechanisms, changes in concentration related to discharge variations or different sediment sources, and in-situ alteration caused by variations in the geochemical conditions (oxy-redox, pH, Eh, etc.). To achieve these goals, we apply a combination of straightforward rock magnetic hysteresis measurements (performed using an AGM2900 at the LSCE) and advanced scanning electron microscopy analyses (SEM). This interdisciplinary approach allows refining the detailed analysis of sediment trap samples, originating from Tessier et al. (2003), as recently shown by Franke et al. (2009). In our preliminary results, we observe a general increase in magnetic concentrations from summer to winter conditions, coupled with a magneto-mineralogic change to rather reduced metallic mineral phases. However, each riversection of the Seine system shows its specific trend line depending on the regional initial input, weathering conditions, drainage area and potential pollution sources. A systematic analysis of the detailed results will allow highlighting the climatic/seasonal influence on the metallic particle assembly. Keywords: Seine river system, environmental magnetism, suspended particulate matter, anthropogenic and natural input, magnetic hysteresis, scanning electron microscopy (SEM),, heavy metal pollution, seasonal variability References: Franke

  15. Towards the determination of an optimal scale for stormwater quality management: micropollutants in a small residential catchment.

    PubMed

    Bressy, A; Gromaire, M-C; Lorgeoux, C; Saad, M; Leroy, F; Chebbo, G

    2012-12-15

    Stormwater and atmospheric deposits were collected on a small residential urban catchment (0.8 ha) near Paris in order to determine the levels of certain micropollutants (using a preliminary scan of 69 contaminants, followed by a more detailed quantification of PAHs, PCBs, alkylphenols and metals). Atmospheric inputs accounted for only 10%-38% of the stormwater contamination (except for PCBs), thus indicating substantial release within the catchment. On this small upstream catchment however, stormwater contamination is significantly lower than that observed downstream in storm sewers on larger adjacent urban catchments with similar land uses. These results likely stem from cross-contamination activity during transfers inside the sewer system and underscore the advantages of runoff management strategies at the source for controlling stormwater pollutant loads. Moreover, it has been shown that both contamination levels and contaminant speciation evolve with the scale of the catchment, in correlation with a large fraction of dissolved contaminants in upstream runoff, which differs from what has been traditionally assumed for stormwater. Consequently, the choice of treatment device/protocol must be adapted to the management scale as well as to the targeted type of contaminant.

  16. Essential requirements for catchment sediments to have ongoing impacts to water clarity in the great barrier reef.

    PubMed

    Gibbs, Mark T

    2016-12-15

    Increasing concerns over decreasing water quality and the state of coral reefs and seagrass meadows along the inshore and mid-shelf regions of the Great Barrier Reef has led to a large-scale government catchment sediment and nutrient reduction program. However the mechanistic understanding of how fine sediments washed out of catchments and transported within flood plumes leads to ongoing increases in turbidity at locations far downstream from estuaries long after flood plumes have dissipated is poorly understood. Essential criteria which need to be met in order for catchment-derived sediments to play a major role in nearshore water quality are proposed. Preliminary estimates of these essential criteria suggest that it is dynamically possible for fine sediments washed out of catchments during floods to be preferentially re-mobilised at downstream locations following the dissipation of flood plumes. However the longer-term influence of catchment-derived material on water quality is dependent upon the rate of degradation of floc particles that fall out of flood plumes and the rate of background deposition; neither of which are well quantified.

  17. Validation of Pacific Northwest hydrologic landscapes at the catchment scale

    EPA Science Inventory

    The interaction between the physical properties of a catchment (form) and climatic forcing of precipitation and energy control how water is partitioned, stored, and conveyed through a catchment (function). Hydrologic Landscapes (HLs) were previously developed across Oregon and de...

  18. Characterizing streamflow generation in Alpine catchments

    NASA Astrophysics Data System (ADS)

    Chiogna, Gabriele; Cano Paoli, Karina; Bellin, Alberto

    2016-04-01

    Developing effective hydrological models for streamflow generation in Alpine catchments is challenging due to the inherent complexity of the intertwined processes controlling water transfer from hillslopes to streams and along the river network. With water discharge as the sole observational variable it is impossible to differentiate between different streamflow sources, and modelling activity is often limited to simplified phenomenological rainfall-runoff models. This study focuses on quantifying streamflow sources at different temporal scales and the associated uncertainty by using natural tracer data (electrical conductivity, oxygen and hydrogen stable isotopes ratios) as observational variables supplementing streamflow measurements. We determine the spatial and temporal hydrological behavior and the mean residence time of water in the Vermigliana catchment, North-Eastern Italy and we separate contributions to streamflow originating from Presena and Presanella glaciers, both exerting a strong control on the hydrologic budget of the study site. Furthermore, we identify a seasonal control on the effect of storm events. The catchment responded rapidly to precipitation events in early autumn, it was unaffected by precipitation events in early spring, while runoff generation was enhanced by snow melting in late autumn. Air temperature is identified as the main controlling parameter, in addition to precipitation. Two-component mixing analysis showed that the relative contribution of new water, which can contribute up to 75% of total streamflow, is very rapid. Only two hours time-lag was observed between the beginning of the precipitation event and the emergence of a significant contribution of new water. These results evidence the relevance of mixing between pre-event and event water in the Vermigliana catchment, and in similar high elevation Alpine catchments. This study provides new insights on the dynamics of streamflow generation in Alpine catchments and a

  19. Environmental isotope hydrology of salinized experimental catchments

    NASA Astrophysics Data System (ADS)

    Turner, J. V.; Arad, A.; Johnston, C. D.

    1987-10-01

    Deuterium, oxygen-18, tritium and chloride concentrations were used in three salinized experimental catchments to gain insight into the mechanism of solute concentration and flow processes in the saturated and unsaturated zones. The three experimental catchments were studied because of their location in different rainfall regions, their status with respect to clearing of native vegetation and with respect to secondary salinization. Two uncleared catchments have average annual rainfalls of approximately 820 and 1220 mm, respectively. The third cleared catchment has an annual rainfall of 650-750 mm. This catchment was in an advanced state of secondary salinization and displayed large areas of saline groundwater discharge with halite encrustation at the ground surface. The stable isotope compositions of the solution phase in solute bulge profiles in the unsaturated zone showed a close agreement with the amount-weighted mean isotopic composition of rainfall and only surficial evidence of isotopic enrichment due to evaporation. Evaporation from the soil surface plays a minor role as a mechanism of solute concentration in the unsaturated zone. The dominant process of solute concentration in the unsaturated zone was ion exclusion during uptake of water by tree roots which was evidently a solute but not isotope fractionating process. Tritium analyses of unsaturated zone water and grondwater indicated movement of recent recharge to 7-10 m depth at the low rainfall site but over the full depth of the 15 m unsaturated zone at the higher rainfall site. The variability in δ18O and δ2H values of groundwaters was used in association with chloride concentrations to provide information on mixing characteristics of groundwaters within the catchments.

  20. Part I: Integrated water quality management: river basin approach. Geochemical techniques on contaminated sediments--river basin view.

    PubMed

    Förstner, Ulrich

    2003-01-01

    The big flood in the upper Elbe River catchment area has revealed a wide spectrum of problems with contaminated sediments. So far, an effective strategy for managing contaminated sediments on a river basin scale is still missing and it seems that not much has been learned from the lessons received during the last decade. In the following overview, special emphasis is given to the utilization of geochemically-based techniques for sediment remediation, which can be applied in different parts of a river basin. The examples presented here are mostly from the Elbe River catchment area. In general, new technical problem solutions need a set of practical process knowledge that uses a wide range of simulation techniques, as well as models in different spatial and temporal scales. The evaluation of recent flood events clearly demonstrates the importance of chemical expertise in the decision-making process for the sustainable development in river basins.

  1. Exploring Hydrological Flow Paths in Conceptual Catchment Models using Variance-based Sensitivity Analysis

    NASA Astrophysics Data System (ADS)

    Mockler, E. M.; O'Loughlin, F.; Bruen, M. P.

    2013-12-01

    Conceptual rainfall runoff (CRR) models aim to capture the dominant hydrological processes in a catchment in order to predict the flows in a river. Most flood forecasting models focus on predicting total outflows from a catchment and often perform well without the correct distribution between individual pathways. However, modelling of water flow paths within a catchment, rather than its overall response, is specifically needed to investigate the physical and chemical transport of matter through the various elements of the hydrological cycle. Focus is increasingly turning to accurately quantifying the internal movement of water within these models to investigate if the simulated processes contributing to the total flows are realistic in the expectation of generating more robust models. Parameter regionalisation is required if such models are to be widely used, particularly in ungauged catchments. However, most regionalisation studies to date have typically consisted of calibrations and correlations of parameters with catchment characteristics, or some variations of this. In order for a priori parameter estimation in this manner to be possible, a model must be parametrically parsimonious while still capturing the dominant processes of the catchment. The presence of parameter interactions within most CRR model structures can make parameter prediction in ungauged basins very difficult, as the functional role of the parameter within the model may not be uniquely identifiable. We use a variance based sensitivity analysis method to investigate parameter sensitivities and interactions in the global parameter space of three CRR models, simulating a set of 30 Irish catchments within a variety of hydrological settings over a 16 year period. The exploration of sensitivities of internal flow path partitioning was a specific focus and correlations between catchment characteristics and parameter sensitivities were also investigated to assist in evaluating model performances

  2. Totten Glacier catchment bed erosion indicates repeated transitions between a modern-scale and a retreated ice sheet

    NASA Astrophysics Data System (ADS)

    Aitken, Alan; Roberts, Jason; van Ommen, Tas; Young, Duncan; Golledge, Nicholas; Greenbaum, Jamin; Blankenship, Don; Siegert, Martin

    2016-04-01

    The Totten Glacier is the outlet for one of the most voluminous catchments in East Antarctica, and shows signs of vulnerability to change. The upstream portions of this catchment include the topographic lows of the Sabrina Subglacial Basin (SSB) and the Aurora Subglacial Basin (ASB), which are surrounded by highland regions. The SSB and ASB each are susceptible to marine instabilities. Here we analyse the subglacial topography of the SSB and the thickness of the underlying sedimentary basin to understand the erosive history of the SSB as a proxy for past ice sheet dynamics. We show that the history of this catchment involves long periods with the ice sheet margin located close to today's, and similarly long periods with the ice sheet margin located hundreds of kilometres further inland. The intervening region is less eroded, suggesting erosion through several repeated transitions between these states, but without prolonged residence. Using numerical ice sheet models, we constrain the likely sea-level contribution of these ice-sheet states. In a retreat from modern scenario, up to 150 km of retreat (~90cm of sea level rise) can be accommodated within the modern-scale state. Further retreat involves marine ice sheet instabilities that drive the ice-sheet extent to the retreated state (2-3 m of sea level rise). Ongoing retreat involves collapse into the ASB, associated with sea level rise in excess of 4m.

  3. Picturing and modelling catchments by representative hillslopes

    NASA Astrophysics Data System (ADS)

    Loritz, Ralf; Hassler, Sibylle; Jackisch, Conrad; Zehe, Erwin

    2016-04-01

    Hydrological modelling studies often start with a qualitative sketch of the hydrological processes of a catchment. These so-called perceptual models are often pictured as hillslopes and are generalizations displaying only the dominant and relevant processes of a catchment or hillslope. The problem with these models is that they are prone to become too much predetermined by the designer's background and experience. Moreover it is difficult to know if that picture is correct and contains enough complexity to represent the system under study. Nevertheless, because of their qualitative form, perceptual models are easy to understand and can be an excellent tool for multidisciplinary exchange between researchers with different backgrounds, helping to identify the dominant structures and processes in a catchment. In our study we explore whether a perceptual model built upon an intensive field campaign may serve as a blueprint for setting up representative hillslopes in a hydrological model to reproduce the functioning of two distinctly different catchments. We use a physically-based 2D hillslope model which has proven capable to be driven by measured soil-hydrological parameters. A key asset of our approach is that the model structure itself remains a picture of the perceptual model, which is benchmarked against a) geo-physical images of the subsurface and b) observed dynamics of discharge, distributed state variables and fluxes (soil moisture, matric potential and sap flow). Within this approach we are able to set up two behavioral model structures which allow the simulation of the most important hydrological fluxes and state variables in good accordance with available observations within the 19.4 km2 large Colpach catchment and the 4.5 km2 large Wollefsbach catchment in Luxembourg without the necessity of calibration. This corroborates, contrary to the widespread opinion, that a) lower mesoscale catchments may be modelled by representative hillslopes and b) physically

  4. Hydrological improvements for nutrient and pollutant emission modeling in large scale catchments

    NASA Astrophysics Data System (ADS)

    Höllering, S.; Ihringer, J.

    2012-04-01

    hydrological system is simulated spatially differentiated and emissions from urban and rural areas into river courses can be detected separately. In the Ruhr catchment (4.485 km2) as a right tributary of the Rhine located in the lower mountain range of North Rhine-Westphalia in Germany for the validation period 2002-2006 the hydrological model showed first satisfying results. The feasibility study in the Ruhr shows the suitability of the approach and illustrates the potentials for further developments in terms of an implementation throughout the German and contiguous watersheds. IWG, Karlsruhe Institute of Technology (KIT). 2011. http://isww.iwg.kit.edu/MoRE.php. [Online] Institute for Water and River Basin Management, Department of Aquatic Environmental Engineering, October 2011. USGS, U.S. Geological Survey. 2009. PRMS-2009, the Precipitation-Runoff Modeling System. Denver, Colorado : s.n., 2009. Bd. U.S. Geologic Survey Open File Report.

  5. Identification of internal flow dynamics in two experimental catchments

    USGS Publications Warehouse

    Hansen, D.P.; Jakeman, A.J.; Kendall, C.; Weizu, G.

    1997-01-01

    Identification of the internal flow dynamics in catchments is difficult because of the lack of information in precipitation -stream discharge time series alone. Two experimental catchments, Hydrohill and Nandadish, near Nanjing in China, have been set up to monitor internal flows reaching the catchment stream at various depths, from the surface runoff to the bedrock. With analysis of the precipitation against these internal discharges, it is possible to quantify the time constants and volumes associated with various flowpaths in both catchments.

  6. Climate Change Impacts in the Upper Rio Grande Catchment

    NASA Astrophysics Data System (ADS)

    Heikkila, T.; Siegfried, T. U.; Sellars, S. L.; Schlager, E.

    2010-12-01

    In the US Southwest, evidence of increased future drought severity and duration in the context of climate change has been detected. Considering the already difficult water distribution and allocation strategies within the region, we are investigating the Costilla Creek, a tributary to the Rio Grande. The catchment is located in Costilla county in Colorado from where on runoff is crossing boundaries between Colorado and New Mexico three times before its confluence with the Rio Grande in New Mexico. Water allocation is governed by an interstate compact between Colorado and New Mexico. While the states have been relatively successful in complying with the compact’s allocation rules, the Costilla Creek catchment has experienced interstate upstream/downstream conflict, mainly during irrigation seasons. Whether or not the states will be able to avert conflict in the future and maintain compliance with the compact, is a critical question. The situation in the relatively small catchment is not unique. Various interstate watersheds, including the entire Rio Grande basin, the La Plata, Arkansas, and Colorado, are expected to face similar impacts from climate change, yet the water compacts that govern them may not be structured to adapt to these conditions. Looking at the Costilla Creek offers a valuable starting point for understanding how to model these effects across various basins. We have developed a lumped-parameter rainfall-runoff model including snow storage of the Costilla Creek watershed. Temperature and precipitation data from NCRS - SNOTEL stations together with USGS gauging station data were utilized for model calibration and validation. ISCCP solar radiation data and temperature data were used to estimate irrigation water demand in irrigated agriculture. The model is driven by the IPCC SRES A2 scenario. GCM ensemble averaged temperature / precipitation trends were extracted for the upper Rio Grande region. 50 year precipitation simulations were created using a

  7. Twenty-first century changes in the hydrology, glaciers, and permafrost of the Susitna Basin, Alaska

    NASA Astrophysics Data System (ADS)

    Bliss, A. K.; Hock, R.; Wolken, G. J.; Zhang, J.; Whorton, E.; Braun, J. L.; Gusmeroli, A.; Liljedahl, A.; Schulla, J.

    2014-12-01

    In the face of climate change, the hydrology of the upper Susitna Basin in South-Central Alaska is expected to change. This would impact the quantity and seasonality of river flow into a proposed hydroelectric dam, if it were to be built. The upper Susitna Basin catchment area is 13,289 km², ranging from 450-4000 m a.s.l. It is 4% glacierized and is characterized by sparse vegetation, discontinuous permafrost, and little human development. We present field measurements and results from hydrological modeling. We present new field data from spring and fall 2014 along with field measurements from the 1980's, 2012, and 2013. These data are used to calibrate and validate the hydrological model. Traditional glacier mass balance measurements show that the glaciers lost more mass in 2012 and 2013 than in 1981, 1982, or 1983. Springtime snow radar surveys of the glaciers allow us to extrapolate from point measurements of snow depth to the whole glacier area. Snow depth measurements at tundra sites as well as tundra vegetation and soil characterizations help us choose appropriate model parameters for the tundra portions of the basin. Meteorological data (temperature, humidity, and precipitation) from over 20 stations in the basin show the summertime temperature lapse rate to be smaller over glacier surfaces compared to ice-free surfaces. Precipitation is highly variable across the basin. Energy balance measurements from two meteorological stations, one located on West Fork Glacier and one on a nunatak near Susitna Glacier, are used for more detailed modeling of summertime glacier melt and runoff. We run a physically-based hydrological model to project 21st century river discharge: Water Flow and Balance Simulation Model (WaSiM). Climate inputs come from a CCSM CMIP5 RCP6.0 scenario downscaled to a 20km-5km nested grid using the Weather Research and Forecasting (WRF) Model. From 2010-2029 to 2080-2099 the basin-wide mean-annual temperature will rise 2.5 degrees and total

  8. High-resolution seismic monitoring of geomorphic activity in a catchment

    NASA Astrophysics Data System (ADS)

    Burtin, A.; Hovius, N.; Turowski, J.; McArdell, B.; Vergne, J.

    2012-04-01

    Continuous survey of the surface activity in a river catchment is essential for the understanding of the landscape dynamics. In steep mountain catchments, a detailed spatial and temporal monitoring of geomorphic processes is generally impossible. The classic techniques (imagery and in situ channel approaches) are not adapted to the extreme conditions that occur during strong rainstorms. There is a real need to develop a method and to define the procedures that will allow the study of surface processes without any environmental dependency. Nowadays, more and more studies explore the use of the seismic instruments to survey the catchment activity. Seismometers can be deployed in sheltered area, which allow us to record in continuous the ground vibrations induced by surface processes, like the sediment transport and mass movements. To continue the exploration of this potential, we deployed a dense array of 10 seismometers in the Illgraben, a 10-km2 catchment in the Swiss Alps, during the summer 2011. This catchment is highly prone to hillslope and debris flow activity, so almost every summer convective storms trigger geomorphic events. The network was designed to monitor the spatial and temporal features of every type of surface activity. Thus during rainstorms, the stations located along the main stream well record the channel activity like the passage of sediment flows, while the instruments installed around the catchment reveal the occurrences of many rockfalls. These latter events show a spectral seismic signature at high frequencies (> 1 Hz), whereas the channel activity is dominant between 10 and 30 Hz. For the largest debris flow of the summer, we are able to identify the location of its initiation from the hillslope. Then, we can map the secondary events, which were triggered by the propagation of the debris flow. With these preliminary results, we demonstrate that the use of a dense seismic array is relevant to map in real time the landscape dynamics at the

  9. Towards large scale modelling of wetland water dynamics in northern basins.

    NASA Astrophysics Data System (ADS)

    Pedinotti, V.; Sapriza, G.; Stone, L.; Davison, B.; Pietroniro, A.; Quinton, W. L.; Spence, C.; Wheater, H. S.

    2015-12-01

    Understanding the hydrological behaviour of low topography, wetland-dominated sub-arctic areas is one major issue needed for the improvement of large scale hydrological models. These wet organic soils cover a large extent of Northern America and have a considerable impact on the rainfall-runoff response of a catchment. Moreover their strong interactions with the lower atmosphere and the carbon cycle make of these areas a noteworthy component of the regional climate system. In the framework of the Changing Cold Regions Network (CCRN), this study aims at providing a model for wetland water dynamics that can be used for large scale applications in cold regions. The modelling system has two main components : a) the simulation of surface runoff using the Modélisation Environmentale Communautaire - Surface and Hydrology (MESH) land surface model driven with several gridded atmospheric datasets and b) the routing of surface runoff using the WATROUTE channel scheme. As a preliminary study, we focus on two small representative study basins in Northern Canada : Scotty Creek in the lower Liard River valley of the Northwest Territories and Baker Creek, located a few kilometers north of Yellowknife. Both areas present characteristic landscapes dominated by a series of peat plateaus, channel fens, small lakes and bogs. Moreover, they constitute important fieldwork sites with detailed data to support our modelling study. The challenge of our new wetland model is to represent the hydrological functioning of the various landscape units encountered in those watersheds and their interactions using simple numerical formulations that can be later extended to larger basins such as the Mackenzie river basin. Using observed datasets, the performance of the model to simulate the temporal evolution of hydrological variables such as the water table depth, frost table depth and discharge is assessed.

  10. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Average Monthly Precipitation, 2002

    USGS Publications Warehouse

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This data set represents the average monthly precipitation in millimeters multiplied by 100 for 2002 compiled for every catchment of NHDPlus for the conterminous United States. The source data were the Near-Real-Time Monthly High-Resolution Precipitation Climate Data Set for the Conterminous United States (2002) raster dataset produced by the Spatial Climate Analysis Service at Oregon State University. 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

  11. Attributes for NHDPlus catchments (version 1.1) for the conterminous United States: Average Annual Daily Maximum Temperature, 2002

    USGS Publications Warehouse

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This data set represents the average monthly maximum temperature in Celsius multiplied by 100 for 2002 compiled for every catchment of NHDPlus for the conterminous United States. The source data were the Near-Real-Time High-Resolution Monthly Average Maximum/Minimum Temperature for the Conterminous United States for 2002 raster dataset produced by the Spatial Climate Analysis Service at Oregon State University. 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

  12. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Average Annual Daily Minimum Temperature, 2002

    USGS Publications Warehouse

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This data set represents the average monthly minimum temperature in Celsius multiplied by 100 for 2002 compiled for every catchment of NHDPlus for the conterminous United States. The source data were the Near-Real-Time High-Resolution Monthly Average Maximum/Minimum Temperature for the Conterminous United States for 2002 raster dataset produced by the Spatial Climate Analysis Service at Oregon State University. 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

  13. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Base-Flow Index

    USGS Publications Warehouse

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This tabular data set represents the mean base-flow index expressed as a percent, compiled for every catchment in NHDPlus for the conterminous United States. 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 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

  14. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Estimated Mean Annual Natural Groundwater Recharge, 2002

    USGS Publications Warehouse

    Wieczorek, Michael; LaMotte, Andrew E.

    2010-01-01

    This data set represents the mean annual natural groundwater recharge, in millimeters, compiled for every catchment of NHDPlus for the conterminous United States. The source data set is Estimated Mean Annual Natural Ground-Water Recharge in the Conterminous United States (Wolock, 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, containing 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

  15. Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: Mean Infiltration-Excess Overland Flow, 2002

    USGS Publications Warehouse

    Wieczorek, Michael; 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 catchment of NHDPlus for the conterminous United States. Infiltration-excess overland flow, expressed as a percent of total overland flow, is simulated in TOPMODEL as precipitation that exceeds the infiltration capacity of the soil and enters the stream channel. The source data set is Infiltration-Excess Overland Flow Estimated by TOPMODEL for the Conterminous United States (Wolock, 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

  16. Contextualising impacts of logging on tropical rainforest catchment sediment dynamics and source processes using the stratigraphic record of an in-channel bench deposit.

    NASA Astrophysics Data System (ADS)

    Blake, W. H.; Walsh, R. P. D.; Bidin, K.; Annammala, K. V.

    2012-04-01

    While rivers draining tropical rainforested catchments are considered to be relatively stable in terms of their hydrological regime, forest disturbance due to logging can lead to extreme, non-linear responses in both flow and sediment load. With growing concern regarding the downstream impacts of enhanced sediment loads and, in particular in tropical regions, the impacts on coastal habitats, data are required to set recent human impacts on drainage basin response into a longer-term natural response context. Landforms that are constructed incrementally by fluvial processes offer sedimentary archives of river basin sediment responses to disturbance. In this regard, floodplain deposits have been used extensively, but less attention has focussed on mid-catchment lateral channel bench deposits. This study reports the stratigraphic record of a mid-catchment lateral bench deposit in the rotationally logged Segama catchment in eastern Sabah, Malaysian Borneo. Accretion rates derived from fallout radionuclide depth profiles (excess Pb-210 and Cs-137) indicate a significant increase in accretion rates since the 1980s when logging operations began and peaks in accretion match known periods of intensive disturbance. Within this framework, downcore profiles of mineral magnetic and geochemical properties are used to infer switches in sediment source from surface/near-surface (slopewash and pipe erosion) to deeper subsurface (landslide) processes in line with the impact of logging operations. The wider role of in-channel bench deposits as sediment stores in disturbed tropical rainforest catchments is considered.

  17. Simultaneous occurrences of floods in mesoscale catchments

    NASA Astrophysics Data System (ADS)

    Bàrdossy, Andràs

    2016-04-01

    Floods in mesoscale catchments are often the result of intense precipitation of varying duration. The spatial extent of precipitation is linked to the extent of flooding. The simultaneous occurrence of floods in different medium size catchments is often the reason for large scale floods. The spatial behavior of extreme precipitation and discharge can be investigated using copulas and extreme indices. The relationship between intense precipitations measured at different locations depends on the large scale meteorological conditions. Depending on the geographic location and the dominating weather pattern certain catchments have frequent simultaneous extremes while others behave in a complementary fashion. The purpose of this work is to investigate the simultaneous and complementary occurrence of floods in catchments using copulas conditioned on atmospheric circulation patterns (CPs). Circulation patterns responsible for simultaneous floods are identified using areal precipitation and/or unusual discharge increases. Patterns are identified using a fuzzy rule based approach based on anomalies of the 700 hPa surfaces. The rules are formed by maximizing the explained variance under the assumption of simultaneous and complementary behavior. The conditional copulas are investigated for extreme behavior. Besides the traditional bivariate investigations higher dimensional dependences are investigated using an entropy based approach.

  18. Ecosystem Services Derived from Headwater Catchments

    EPA Science Inventory

    We used data from the USEPA’s wadeable streams assessment (WSA), US Forest Service’s forest inventory and analysis (FIA), and select USFS experimental forests (EF) to investigate potential ecosystems services derived from headwater catchments. C, N, and P inputs to these catchmen...

  19. Hydrological Modelling of Small Catchments Using Swat

    NASA Astrophysics Data System (ADS)

    Kannan, N.; White, S. M.; Worrall, F.; Groves, S.

    The data from a 142ha catchment in Eastern England(Colworth, Bedfordshire)are be- ing used to investigate the performance of the USDA SWAT software for modelling hydrology of small catchments. Stream flow at the catchment outlet has been mon- itored since October 1999. About 50% of the total catchment is directly controlled within one farm and a rotation of wheat, oil seed rape, grass, linseed, beans and peas is grown. Three years of stream flow and climate data are available. Calibration and validation of stream flow was carried out with both runoff modelling options in the SWAT model (USDA curve number method and the Green and Ampt method). The Nash and Sutcliffe efficiencies for the calibration period were 66% and 63% respec- tively. The performance of SWAT was better in the validation period as a whole, with regard to timing of peaks, baseflow values and Nash and Sutcliffe efficiency. An ef- ficiency of 70% was obtained using the curve number method, which is comparable with the efficiencies obtainable with more complex models. Despite this performance, SWAT is under predicting stream flow peaks. A detailed investigation of important model components, has allowed us to identify some of the reasons for under predic- tion of stream flow peaks.

  20. Catchment scale afforestation for mitigating flooding

    NASA Astrophysics Data System (ADS)

    Barnes, Mhari; Quinn, Paul; Bathurst, James; Birkinshaw, Stephen

    2016-04-01

    After the 2013-14 floods in the UK there were calls to 'forest the uplands' as a solution to reducing flood risk across the nation. At present, 1 in 6 homes in Britain are at risk of flooding and current EU legislation demands a sustainable, 'nature-based solution'. However, the role of forests as a natural flood management technique remains highly controversial, due to a distinct lack of robust evidence into its effectiveness in reducing flood risk during extreme events. SHETRAN, physically-based spatially-distributed hydrological models of the Irthing catchment and Wark forest sub-catchments (northern England) have been developed in order to test the hypothesis of the effect trees have on flood magnitude. The advanced physically-based models have been designed to model scale-related responses from 1, through 10, to 100km2, a first study of the extent to which afforestation and woody debris runoff attenuation features (RAFs) may help to mitigate floods at the full catchment scale (100-1000 km2) and on a national basis. Furthermore, there is a need to analyse the extent to which land management practices, and the installation of nature-based RAFs, such as woody debris dams, in headwater catchments can attenuate flood-wave movement, and potentially reduce downstream flood risk. The impacts of riparian planting and the benefits of adding large woody debris of several designs and on differing sizes of channels has also been simulated using advanced hydrodynamic (HiPIMS) and hydrological modelling (SHETRAN). With the aim of determining the effect forestry may have on flood frequency, 1000 years of generated rainfall data representative of current conditions has been used to determine the difference between current land-cover, different distributions of forest cover and the defining scenarios - complete forest removal and complete afforestation of the catchment. The simulations show the percentage of forestry required to have a significant impact on mitigating

  1. Drought characteristics and related risks in large and mesoscale tropical catchments in Latin-America and South East Asia

    NASA Astrophysics Data System (ADS)

    Nauditt, Alexandra; Ribbe, Lars; Birkel, Christian; Célleri, Rolando

    2016-04-01

    Seasonal meteorological and hydrological droughts are a recurrent phenomenon in water abundant tropical countries and are expected to become more frequent in the future. Unusual water shortage in the past months and years has severely affected societies living in the Paraiba do Sul river basin (Brazil), the Mekong, as well as in a number of basins in Central America and Vietnam among many others. Preparedness, however, is absent and site appropriate water management measures and strategies are not available. While drought related research and water management in recent years has been widely addressed in water scarce subtropical regions, the US and Europe, not much attention has been paid to drought risk in tropical catchments. Available daily or monthly precipitation and runoff time series for catchments in Brazil, Costa Rica, Ecuador, the Mekong region and Vietnam were analysed to compare historical meteorological and hydrological drought frequency (SPI/SRI). The role of tropical catchment characteristics, storage and climate variability in seasonal drought evolvement was investigated by applying the conceptual semi-distributed HBV light model to two undisturbed catchments in Central Vietnam and 18 catchments of a size of 70-5000 km² in Costa Rica. For the Mekong and the Paraíba de Sul, the hydrological module of the WEAP model was applied to undisturbed subcatchments with the same objective. To understand and separate the anthropogenic impact on drought evolvement, the abstractions (irrigation, reservoirs, water supply) and hydrological alterations were observed and quantified by applying water allocation and balance model WEAP. We conclude that such a combined model-data analysis that equally accounts for landscape related and anthropogenic impacts on the local hydrological cycle is a useful approach for drought management in tropical countries.

  2. Dilution correction equation revisited: The impact of stream slope, relief ratio and area size of basin on geochemical anomalies

    NASA Astrophysics Data System (ADS)

    Shahrestani, Shahed; Mokhtari, Ahmad Reza

    2017-04-01

    Stream sediment sampling is a well-known technique used to discover the geochemical anomalies in regional exploration activities. In an upstream catchment basin of stream sediment sample, the geochemical signals originating from probable mineralization could be diluted due to mixing with the weathering material coming from the non-anomalous sources. Hawkes's equation (1976) was an attempt to overcome the problem in which the area size of catchment basin was used to remove dilution from geochemical anomalies. However, the metal content of a stream sediment sample could be linked to several geomorphological, sedimentological, climatic and geological factors. The area size is not itself a comprehensive representative of dilution taking place in a catchment basin. The aim of the present study was to consider a number of geomorphological factors affecting the sediment supply, transportation processes, storage and in general, the geochemistry of stream sediments and their incorporation in the dilution correction procedure. This was organized through employing the concept of sediment yield and sediment delivery ratio and linking such characteristics to the dilution phenomenon in a catchment basin. Main stream slope (MSS), relief ratio (RR) and area size (Aa) of catchment basin were selected as the important proxies (PSDRa) for sediment delivery ratio and then entered to the Hawkes's equation. Then, Hawkes's and new equations were applied on the stream sediment dataset collected from Takhte-Soleyman district, west of Iran for Au, As and Sb values. A number of large and small gold, antimony and arsenic mineral occurrences were used to evaluate the results. Anomaly maps based on the new equations displayed improvement in anomaly delineation taking the spatial distribution of mineral deposits into account and could present new catchment basins containing known mineralization as the anomaly class, especially in the case of Au and As. Four catchment basins having Au and As

  3. Groundwater resource sustainability in the Nabogo Basin of Ghana

    NASA Astrophysics Data System (ADS)

    Lutz, Alexandra; Thomas, James M.; Pohll, Greg; McKay, W. Alan

    2007-10-01

    In order to address groundwater resource sustainability, a conceptual groundwater flow model is developed for a hydrographic basin of northern Ghana. A three-dimensional steady-state model is applied to the Nabogo Basin, a sub-catchment of the White Volta River Basin. Mean annual data are used for input parameters. Parameters include rates of precipitation, recharge, surface water discharge, and groundwater extraction (pumpage). The model indicates that current well pumpage rates are significantly less than annual groundwater recharge to the basin. Model results for several scenarios tested (i.e., increased population, access to potable water for all citizens, and/or decreased rainfall) indicate that extraction rates will still be less than groundwater input to the basin.

  4. Implementation of E.U. Water Framework Directive: source assessment of metallic substances at catchment levels.

    PubMed

    Chon, Ho-Sik; Ohandja, Dieudonne-Guy; Voulvoulis, Nikolaos

    2010-01-01

    The E.U. Water Framework Directive (WFD) aims to prevent deterioration of water quality and to phase out or reduce the concentrations of priority substances at catchment levels. It requires changes in water management from a local scale to a river basin scale, and establishes Environmental Quality Standards (EQS) as a guideline for the chemical status of receiving waters. According to the Directive, the standard and the scope of the investigation for water management are more stringent and expanded than in the past, and this change also needs to be applied to restoring the level of metals in water bodies. The aim of this study was to identify anthropogenic emission sources of metallic substances at catchment levels. Potential sources providing substantial amounts of such substances in receiving waters included stormwater, industrial effluents, treated effluents, agricultural drainage, sediments, mining drainage and landfill leachates. Metallic substances have more emission sources than other dangerous substances at catchment levels. Therefore, source assessment for these substances is required to be considered more significantly to restore their chemical status in the context of the WFD. To improve source assessment quality, research on the role of societal and environmental parameters and contribution of each source to the chemical distribution in receiving waters need to be carried out.

  5. A simple framework for relating variations in runoff to variations in climatic conditions and catchment properties

    NASA Astrophysics Data System (ADS)

    Roderick, Michael L.; Farquhar, Graham D.

    2011-12-01

    We use the Budyko framework to calculate catchment-scale evapotranspiration (E) and runoff (Q) as a function of two climatic factors, precipitation (P) and evaporative demand (Eo = 0.75 times the pan evaporation rate), and a third parameter that encodes the catchment properties (n) and modifies how P is partitioned between E and Q. This simple theory accurately predicted the long-term evapotranspiration (E) and runoff (Q) for the Murray-Darling Basin (MDB) in southeast Australia. We extend the theory by developing a simple and novel analytical expression for the effects on E and Q of small perturbations in P, Eo, and n. The theory predicts that a 10% change in P, with all else constant, would result in a 26% change in Q in the MDB. Future climate scenarios (2070-2099) derived using Intergovernmental Panel on Climate Change AR4 climate model output highlight the diversity of projections for P (±30%) with a correspondingly large range in projections for Q (±80%) in the MDB. We conclude with a qualitative description about the impact of changes in catchment properties on water availability and focus on the interaction between vegetation change, increasing atmospheric [CO2], and fire frequency. We conclude that the modern version of the Budyko framework is a useful tool for making simple and transparent estimates of changes in water availability.

  6. Morphometric analysis of Suketi river basin, Himachal Himalaya, India

    NASA Astrophysics Data System (ADS)

    Pophare, Anil M.; Balpande, Umesh S.

    2014-10-01