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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)

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

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

2013-04-01

2

Parallel Computing of Catchment Basins in Large Digital Elevation Model  

E-print Network

, to initial geographical catchment basin computing. Watershed transform algorithms use two method classesParallel Computing of Catchment Basins in Large Digital Elevation Model Hiep-Thuan Do , S a fast and flexible parallel implementation to com- pute catchment basins in the large digital elevation

Melin, Emmanuel

3

Are big basins just the sum of small catchments?  

Microsoft Academic Search

Many challenges remain in extending our understanding of how hydrologic processes within small catchments scale to larger river basins. In this study we examine how low-flow runoff varies as a function of basin scale at 11 catchments, many of which are nested, in the 176 km2 Neversink River watershed in the Catskill Mountains of New York. Topography, vegetation, soil and

Jeffrey Shaman; Marc Stieglitz; Doug Burns

2004-01-01

4

Are big basins just the sum of small catchments?  

USGS Publications Warehouse

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

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

2004-01-01

5

Intra-basin variability of snowmelt water balance calculations in a subarctic catchment  

Microsoft Academic Search

The intra-basin variability of snowmelt and melt-water runoff hydrology in an 8 km2 subarctic alpine tundra catchment was examined for the 2003 melt period. The catchment, Granger Creek, is within the Wolf Creek Research Basin, Yukon, which is typical of mountain subarctic landscapes in northwestern Canada. The study catchment was segmented into nine internally uniform zones termed hydrological response units

Stephen E. McCartney; Sean K. Carey; John W. Pomeroy

2006-01-01

6

Preliminary investigation of catchment hydrology in response to agricultural water use innovations: A case study of the Potshini catchment South Africa  

NASA Astrophysics Data System (ADS)

Water use system innovations encompass various techniques for storing and conserving water resources in different mediums for domestic and livestock use including agricultural production. Although, several authors have indicated that rainwater harvesting techniques, especially for upgrading smallholder farming systems, are not new but have been practiced since ancient civilizations, the impacts of such water use innovations on eco-hydrological systems are rarely assessed, especially from a cascading spatial and temporal perspective. The need to quantify the supposedly potential and related hydrological impacts of water use innovations on a catchment and river basin at large, led to the on-going research study aimed at investigating the biophysical consequences at different spatial and temporal scales in the Thukela river basin, of increased productivity in smallholder rainfed agriculture enabled through adoption at larger spatial scale of integrated land use management and water use system innovations. In this paper we discuss and outline the approach used in setting up the research study in one of the catchments in the Thukela river basin, the Potshini catchment, in the KwaZulu-Natal Province of South Africa in an effort to seek answers to the question: “What is the impact of adapting water use innovations in a predominantly agricultural area on catchment ecology and hydrology?” The approach incorporates a catchment monitoring network, hydrological modelling and application of a remote sensing technique, the Surface Energy Balance Algorithm for Land (SEBAL), for spatially estimating the total evaporation in the region covering the Potshini catchment and beyond. Preliminary results indicate that water use innovations in the Potshini catchment have influenced the partitioning of rainfall, by significantly reducing surface runoff over agricultural lands under conservation tillage practices, with a reduction of above 100%, while encouraging infiltration and deeper percolation into the soil. It is envisaged that, on accomplishment, the study will contribute to formulation of sustainable adaptation of water use innovations and up-scaling strategies to enhance food production and hydro-ecological balance in semi-arid savannahs of Africa, at which stage hydrological modelling will form an important part of the study.

Kongo, V. M.; Jewitt, G. P. W.

7

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

PubMed

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. PMID:21261066

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

2010-11-01

8

UPPER SNAKE RIVER BASIN, PRELIMINARY BASIN EVALUATION  

EPA Science Inventory

The purpose of this paper was to provide a process and a plan by which the Environmental Protection Agency can insure that water quality goals established in the Water Pollution Control Act Amendments of 1972 are met in the waters of the Upper Snake Basin (17040201, 17040206, 170...

9

Regionalising a meso-catchment scale conceptual model for river basin management in the semi-arid environment  

NASA Astrophysics Data System (ADS)

Meso-scale catchments are often of great interest for water resources development and for development interventions aimed at uplifting rural livelihoods. However, in Sub-Saharan Africa IWRM planning in such catchments, and the basins they form part of, are often ungauged or constrained by poor data availability. Regionalisation of a hydrological model presents opportunities for prediction in ungauged basins and catchments. This study regionalises HBVx, derived from the conceptual hydrological model HBV, in the semi-arid Mzingwane Catchment, Limpopo Basin, Zimbabwe. Fifteen meso-catchments were studied, including three that were instrumented during the study. Discriminant analysis showed that the characteristics of catchments in the arid agro-ecological Region V were significantly different from those in semi-arid Region IV. Analysis of flow duration curves statistically separated sub-perennial catchments from (sub-)ephemeral catchments. Regionalised parameter sets for HBVx were derived from means of parameters from the sub-perennial catchments, the (sub-)ephemeral catchments and all catchments. The parameter sets that performed best in the regionalisation are characterised by slow infiltration with moderate/fast “overland flow”. These processes appear more extreme in more degraded catchments. This is points to benefits to be derived from conservation techniques that increase infiltration rate and from runoff farming. Faster, and possibly greater, sub-surface contribution to streamflow is expected from catchments underlain by granitic rocks. Calibration and regionalisation were more successful at the dekad (10 days) time step than when using daily or monthly data, and for the sub-perennial catchments than the (sub-)ephemeral catchments. However, none of the regionalised parameter sets yielded C NS ? 0.3 for half of the catchments. The HBVx model thus does offer some assistance to river basin planning in semi-arid basins, particularly for predicting flows in ungauged catchments at longer time steps, such as for water allocation purposes. However, the model is unreliable for more ephemeral and drier catchments. Without more reliable and longer rainfall and runoff data, regionalisation in semi-arid ephemeral catchments will remain highly challenging.

Love, David; Uhlenbrook, Stefan; van der Zaag, Pieter

10

Isotope hydrology of catchment basins: lithogenic and cosmogenic isotopic systems  

Microsoft Academic Search

A variety of physical processes affect solute concentrations within catchment waters. The isotopic compositions of the solutes can indicate which processes have determined the observed concentrations. These processes together constitute the physical history of the water. Many solutes in natural waters are derived from the interaction between the water and the rock and\\/or soil within the system - these are

Nimz

1998-01-01

11

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

USGS Publications Warehouse

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

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

12

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

NASA Astrophysics Data System (ADS)

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.

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

2015-03-01

13

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

14

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

NASA Astrophysics Data System (ADS)

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

Spray, Christopher

2013-04-01

15

Towards seasonal hydrological forecasting in mountain catchments: preliminary results from the APRIL project  

NASA Astrophysics Data System (ADS)

The APRIL project aims at addressing the long term quantitative prediction of monthly discharge from mountain catchments and setting up a system which can then be used operationally. More specifically, its objectives are: - To investigate the potential of EO products (snow cover extent, vegetation and soil moisture statust) and weather/climatic variables for the prediction of water streamflow from mountain catchments - To develop a robust methodology for the long term quantitative forecast of montly discharge from EO and weather/climatic data - To build a fully operational system for seasonal hydrological forecasting. This contribution illustrates the general concept of the project as well as some preliminary results. Water discharge in mountain catchments is physically related to antecedent snow cover and climatology (precipitation, temperature). Other factors may play a role, such as vegetation/soil status and topography. Historical discharge measurements and earth observation (EO) data are a valuable source for inferring the quantitative relationship between the discharge and its predictors using appropriate techniques. The prediction is based on the Support Vector Regression (SVR)technique, a state of the art machine learning regression method with good intrinsic generalization ability and robustness. In the contribution we present and discuss results of a preliminary analysis on water discharge prediction ( with lead time of 1 to 3 months) in South Tyrol, Italy. Despite the use of a limited set of predictors (among which mainly snow cover area), the results are encouraging. The analysis is in the process of being extended at different spatial scales, which will give the possibility to investigate different aspects of the problem and develop different prediction systems; by updating on the current developments, the contribution discusses also perspectives and current limitations towards the set up of a fully operational seasonal hydrological forecasting system in Europe.

Pistocchi, Alberto; Mazzoli, Paolo; Bagli, Stefano; Notarnicola, Claudia; Pasolli, Luca

2013-04-01

16

Upscaling discrete internal observations for obtaining catchment-averaged TOPMODEL parameters in a small Mediterranean mountain basin  

Microsoft Academic Search

Discrete observations on recession flows, local depth to the water table and the extent of saturated areas were used in the Vallcebre small research basin for obtaining the distribution functions of the TOPMODEL catchment parameters that drive the behaviour of the saturated store. Using this parameter information within GLUE framework, the robustness of discharge simulations was improved and the uncertainty

Francesc Gallart; Jérôme Latron; Pilar Llorens; Keith J. Beven

2008-01-01

17

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

NASA Astrophysics Data System (ADS)

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 estimate water demand and calculate water use balance in 2015, 2021. The result of the water balance estimation shows that water consumption-use will be increased 3 times in the river basin by 2021. As the water consumption-use source, surface water - 6.4 % and groundwater is 93.6 percent. The current consumption of the mining sector is shares 71 percent of the total users; it would be 82 percent in 2021. However, the livestock water consumption-use is 27 percent of the current demand; it would be decrease up to 16 percent in 2021. Ecosystem based approach IWRM plan would be efficient to the local resident to adapt the climate change situation. Thus, the results of the research study on the river basin ecosystem services and values are the base of the planning.

Tugjamba, Navchaa; Sereeter, Erdenetuul; Gonchigjav, Sarantuya

2014-05-01

18

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

NASA Astrophysics Data System (ADS)

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.

Restrepo, Juan D.

2008-04-01

19

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

USGS Publications Warehouse

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

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

2012-01-01

20

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

USGS Publications Warehouse

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

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

21

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

NASA Astrophysics Data System (ADS)

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

Hüffmeyer, N.; Berlekamp, J.; Klasmeier, J.

2009-04-01

22

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

23

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

24

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

25

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

26

Transient catchment hydrology after wildfires in a Mediterranean basin: runoff, sediment and woody debris Hydrol. Earth Syst. Sci., 11(1), 125140, 2007  

E-print Network

Transient catchment hydrology after wildfires in a Mediterranean basin: runoff, sediment and woody after wildfires in a Mediterranean basin: runoff, sediment and woody debris Renzo Rosso, Maria Cristina, transient complexity after wildfires can be addressed by such an approach with empirically determined

Paris-Sud XI, Université de

27

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

PubMed

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

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

2014-05-01

28

Isotopic time-series partitioning of streamflow components in wetland-dominated catchments, lower Liard River basin, Northwest Territories, Canada  

NASA Astrophysics Data System (ADS)

The distribution of stable water isotopes provides valuable insight into runoff generation processes in subarctic wetland regions of the Mackenzie River basin, a major freshwater contributor to the Arctic Ocean and the focus of intensive hydrological research as part of Canada's contribution to the Global Energy and Water Cycle Experiment (GEWEX). This article describes a streamflow hydrograph separation analysis carried out over three complete annual cycles (1997-1999) for five subarctic catchments ranging in size from 202 to 2050 km2 situated near the confluence of the Liard and Mackenzie rivers. This heterogeneous landscape, characterized by extensive wetlands (fen and bog), shallow lakes and widespread discontinuous permafrost, is representative of vast flow-contributing areas of the upper Mackenzie Valley, and is suspected to be highly sensitive to climate variability and change. We document seasonal patterns and interannual variability in the isotopic composition of local streamflow, attributable to mixing of three distinctly labelled flow sources, namely groundwater, surface water plus rain, and direct snowmelt, and apply these isotopic signals to partition sources and their temporal variability. Although groundwater input is the dominant and most persistent streamflow source in all five catchments throughout the year, direct snowmelt runoff via surface and shallow subsurface pathways (during spring freshet) and surface waters from lakes and wetlands situated in low-lying areas of the basins (during summer and fall) are also significant seasonal contributors. Catchment-specific differences are also apparent, particularly in the generation of snowmelt runoff, which is more attenuated in fen-dominated than in bog-dominated catchments. The data set additionally reveals notable interannual variability in snow isotope signatures and snow water equivalent, apparently enhanced by the 1998 El Niño event. Copyright

St Amour, Natalie A.; Gibson, John J.; Edwards, Thomas W. D.; Prowse, Terry D.; Pietroniro, Alain

2005-11-01

29

CRC FOR CATCHMENT HYDROLOGY CSIRO LAND AND WATER FLINDERS UNIVERSITY OF SOUTH AUSTRALIA CHARACTERISATION AND RANKING OF BASINS IN THE MURRAY BASIN OF  

E-print Network

for Salt Storage within Irrigation Areas ’ was based on the premise that disposal basins are 'a fact of life ' in the Murray-Darling Basin. Consequently there is a need for guidelines to site, design and manage them to minimise environmental and other problems. However, more than 190 existing basins were built when there were no such guidelines. Some were well designed and sited, some less so. It is important that we not only design better basins in future, but also maintain our existing basins in an appropriate fashion. In some cases, we may need to decommission them. This report describes a methodology for maintaining a portfolio of disposal basins and describes the minimum dataset for doing so. It is then possible to focus attention on those that present the greatest risk and for which more work may be needed. The example uses thirty existing basins. Our selection was most probably biased towards basins we have the most information about. Nonetheless, the attempt to rank them is thwarted by a lack of even minimal information. This is despite some recent work by AGSO in compiling information on existing basins. Because of the lack of information, the list here should be considered preliminary and used as a basis for further discussion on how we manage our existing basins. This is not an output from the MDBC-funded grant on on-farm and community basins in the Riverine Plains, although it complements that work.

South-eastern Australia; Craig Simmons; Wei Yan; Kumar Narayan; Glen Walker

30

A 200-year historical modeling of catchment nutrient changes in Taihu basin, China  

Microsoft Academic Search

Sedimentary records provide important information for understanding changes in the history of eutrophication in Lake Taihu.\\u000a In addition, the catchment nutrient model SWAT provides a powerful tool to examine eutrophic changes in a long-term context.\\u000a Since it is difficult to evaluate impacts of natural eutrophic development and anthropogenic changes in catchment discharge\\u000a and land use, simulation of past changes provides

Ge Yu; Bin Xue; Geying Lai; Feng Gui; Xiaomei Liu

31

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

NASA Astrophysics Data System (ADS)

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

Sarp, Gulcan

2015-02-01

32

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

USGS Publications Warehouse

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

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

33

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

NASA Astrophysics Data System (ADS)

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

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

2009-02-01

34

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

35

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)

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

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

2013-12-01

36

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

37

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

PubMed

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

Naicker, S; Demlie, M

2014-01-01

38

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

USGS Publications Warehouse

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

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

39

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

40

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

NASA Astrophysics Data System (ADS)

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, CM4.1, PCM1, CGCM3.1T47, MIROC3.2.HIRES, CCSM3.0 and FGOALS, are the most inconsistent with the observed rainfall for both catchments. Good performing models are MK3.5, MK3.0, ECHAM5, CM2.1U.H2 and CM2.0. In general, most GCMs perform poorly for both catchments. This signals the need for significant improvements in the rainfall modelling of the climate models for the study region. There is no strong evidence to suggest that GCM performance improves with higher spatial resolution. Models which are highly inconsistent with other models in reproducing the observed rainfall are not necessarily inconsistent with other models in the future projections. Differences in projections for the A1B, B2, and B1 scenarios were found to be smaller than the differences between the GCM simulations.

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

41

Simulating wind-affected snow accumulations at catchment to basin scales  

NASA Astrophysics Data System (ADS)

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 computational efficiency and modest data requirements of this approach are ideally suited for large-scale operational applications.

Winstral, Adam; Marks, Danny; Gurney, Robert

2013-05-01

42

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

43

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

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

44

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

PubMed Central

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

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

2015-01-01

45

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

NASA Astrophysics Data System (ADS)

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.

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

46

Seismic Response of a Sedimentary Basin: Preliminary Results from Strong Motion Downhole Array in Taipei Basin  

NASA Astrophysics Data System (ADS)

The Strong Motion Downhole Array (SMDA) is an array of 32 triggered strong motion broadband seismometers located at eight sites in Taipei Basin. Each site features three to five co-located three-component accelerometers--one at the surface and an additional two to four each down independent boreholes. Located in the center of Taipei Basin is Taipei City and the Taipei metropolitan area, the capital of Taiwan and home to more than 7 million residents. Taipei Basin is in a major seismic hazard area and is prone to frequent large earthquakes producing strong ground motion. This unique three-dimension seismic array presents new frontiers for seismic research in Taiwan and, along with it, new challenges. Frequency-dependent and site-specific amplification of seismic waves from depth to surface has been observed: preliminary results indicate that the top few tens of meters of sediment--not the entire thickness--are responsible for significant frequency-dependent amplification; amplitudes of seismic waves at the surface may be as much as seven times that at depth. Dominant amplification frequencies are interpreted as quarter-wavelength constructive interference between the surface and major interfaces in the sediments. Using surface stations with known orientation as a reference, borehole seismometer orientations in these data--which are unknown, and some of which vary considerably from event to event--have been determined using several methods. After low-pass filtering the strong motion data, iteratively rotating the two horizontal components from an individual borehole station and cross-correlating them with that from a co-located surface station has proven to be very effective. In cases where the iterative cross-correlation method does not provide a good fit, rotating both surface and borehole stations to a common axis of maximum seismic energy provides an alternative approach. The orientation-offset of a borehole station relative to the surface station may be estimated by iteratively rotating the horizontal components of both and calculating the time-integral of the amplitude squared of each component; the difference in orientation between the maximum at the surface and at depth indicates the difference in orientation of the seismometers. After the horizontal orientations of borehole seismometers are correctly resolved, these data can be used in various scientific studies. Up-going and reflected down-going shear waves can be clearly identified, providing an excellent dataset for the study of interval velocity and seismic Q, localized shear wave splitting, and anisotropy. Further refinement of the geophysical structure of Taipei Basin and Northern Taiwan is also possible by combining data from the SMDA with that from the large array of surface stations maintained by the Central Weather Bureau.

Young, B.; Chen, K.; Chiu, J.

2013-12-01

47

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

48

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

49

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

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

Kim, Eung Seok; Choi, Hyun Il

2012-01-01

50

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

51

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

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

52

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

USGS Publications Warehouse

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

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

53

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

54

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

55

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

56

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

57

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

58

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

59

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

60

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

61

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

62

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

63

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

64

Bromine species fluxes from Lake Constance’s catchment, and a preliminary lake mass balance  

NASA Astrophysics Data System (ADS)

Bromine was historically termed a cyclic salt in terrestrial freshwater environments due to its perceived conservative cycling between the oceans and the continents. This basic assumption has been challenged recently, with evidence that bromine is involved in dynamic chemical cycles in soils and freshwaters. We present here a study on dissolved bromine species (bromide, organically bound bromine, DOBr) concentrations and fluxes as well as sediment trap bromine levels and fluxes in Lake Constance, a large lake in southern Germany. Water samples were obtained from all major and some minor inflows and outflows over one year, where-after dissolved bromine species were measured by a combination of ICP-MS and ion chromatography coupled to an ICP-MS (IC-ICP-MS). Sediment traps were deployed at two locations for two years with Br, Ti and Zr levels being measured by ?-XRF. 190 t yr -1 of total dissolved bromine (TDBr) was delivered to the lake via 14 rivers and precipitation, with the rivers Alpenrhein (84 t TDBr yr -1) and the Schussen (50 t TDBr yr -1) providing the largest sources. The estimated particulate bromine flux contributed an extra 24-26 t Br yr -1. In comparison, only 40 t TDBr yr -1 was deposited to the lake's catchment by precipitation, and thus ˜80% of the riverine TDBr flux came from soils and rocks. Bromide was the dominant species accounting for, on average, 78% of TDBr concentrations and 93% of TDBr flux to the lake. Despite some high concentrations in the smaller lowland rivers, DOBr was only a minor component of the total riverine bromine flux (˜12 t yr -1, 7%), most of which came from the rivers Schussen, Bregenzer Ach and Argen. In contrast, most of the bromine in the sediment traps was bound to organic matter, and showed a clear seasonal pattern in concentrations, with a maximum in winter and minimum in summer. The summer minimum is thought to be due to dilution of a high Br autochthonous component by low bromine mineral and organic material from the catchment, which is supported by Ti, Zr and Br/C org data. In the lake bromine was irreversibly lost to the sediments, with best flux estimates based on mass-balance and sediment trap data of +50-90 ?g Br m -2 d -1. Overall, it appears that bromine is not simply a cyclic salt in the case of Lake Constance, with a clear geological component and dynamic lacustrine biogeochemistry.

Gilfedder, B. S.; Petri, M.; Wessels, M.; Biester, H.

2011-06-01

65

Preliminary catalog of the sedimentary basins of the United States  

USGS Publications Warehouse

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.

Coleman, James L.; Cahan, Steven M.

2012-01-01

66

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

67

Catchment-scale contaminant transport under changing hydro-climatic conditions in the Aral Sea Drainage Basin, Central Asia  

NASA Astrophysics Data System (ADS)

Dependable projections of future water availability and quality are essential in the management of water resources. Changes in land use, water use and climate can have large impacts on water and contaminant flows across extensive catchments that may contain different administrative regions where shared water resources must be managed. We consider the extensive Aral Sea Drainage Basin (ASDB) and the Amu Darya River Delta in Central Asia, which are currently under severe water stress due to large-scale irrigation expansion. We interpret data on hydro-climatic conditions, main contaminants of surface water and shallow groundwater systems, location of rivers and canal networks, and groundwater flow directions. The data are used together with climate change projections from general circulation models (GCMs) as input to hydrological and (advective) transport modelling. The main goal is to assess how regional transport pathways and travel times have changed, and are likely to change further, in response to past and projected future hydro-climatic changes. More specifically, the hydrological modelling was based on temperature and precipitation change (?T and ?P) results from 65 GCM projections of 21st century conditions (specifically considering time periods around 2025, 2050, and 2100), relative to reference conditions around 1975 (taken from the reference period 1961-1990). Whereas ?T is robustly projected to increase with time, the projected magnitude of ?P differs more among projections for the distant future (2100) than for the near future (2025), with uncertainty remaining even about the direction of change (i.e., positive or negative ?P). However, mainly due to the projected temperature-driven increases in evapotranspiration, ensemble average results show that the Amu Darya river discharge Q in the downstream ASDB is likely to show a decreasing trend throughout the 21st century. Notably, projected changes in the upstream, mountainous regions have a relatively large impact on these Q-projections. For example, the locally created runoff of the downstream region is projected to be maintained or even increase slightly, in contrast to the decreasing Q-trend that reflects an integrated, average response of the entire catchment. A continued drying of surface waters within the Amu Darya river delta implies that advective travel times are increasingly governed by the groundwater system. Such diminished exchanges with surface waters imply increased mean travel times from shallow groundwaters to the (drying) river and drainage canal network by an order of magnitude (from months to years). This can considerably influence mass flow and retention of contaminants in the river delta region, which suffers from e.g. copper, chromium and lead contamination.

Jarsjö, Jerker; Törnqvist, Rebecka; Su, Ye

2013-04-01

68

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

69

Preliminary design report for the K basins integrated water treatment system  

SciTech Connect

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.

Pauly, T.R., Westinghouse Hanford

1996-08-12

70

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

71

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

USGS Publications Warehouse

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

72

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

73

A Preliminary OBS Data Analysis in the West Philippine Basin  

NASA Astrophysics Data System (ADS)

During Leg 4 of TAIGER MCS/OBS experiment (June-July 2009), a long profile of 550 km was shot by R/V Langseth in the West Philippine Basin. We placed 28 short-period OBSs at a station-to-station distance of 15 km along this profile. This profile was designed to be 90 degree to the spreading fabric as previously mapped by the multi-beam echo-sounding data. Because of the Typhoon Molave, R/V Langseth shot 3 times to complete the whole track. The large air-gun sources and over-lapping shoots allow us to place the shoot geometry at either a single-combined profile or 3 separated profiles. We are investigating the best result from these two different geometry models. The age-depth relationship shows that the bathymetry is deeper toward the north, the Ryukyu Subduction Zone, however, the magnetic modeling suggest the older West Philippine Basin crust is in the south. An initial OBS model indicates the Pn arrival can be traced up to 80 more km away from the OBS station center. More interpretations will be elucidated for the crustal evolution of the West Philippine Basin in the near future. Drs. Shu-Kun Hsu and Kirk MacIntash were the chief scientists of Leg 4 TAIGER cruise on board R/V Langseth. We provided several ships to support the OBS experiment. These data were collected by a multi-ship operation.

Lai, W.; Huang, W.; Lee, C.

2009-12-01

74

Analysis of Cheshire basin by gravity method: Some preliminary results  

NASA Astrophysics Data System (ADS)

Gravity data acquired from Cheshire basin located in the northwestern part of the United Kingdom were processed and analysed to determine the structural pattern within the entire sedimentary basin. A total of 753 gravity data were obtained from the British Geological Society and with the aid of Oasis Montaj software, maps of Bouguer anomaly, isostatic and total horizontal derivative were obtained for qualitative and quantitative interpretation in determining the fault trend and the tectonic system of the study area. The positive Bouguer anomaly region found in the northwest of the study area is associated with the high density sedimentary rocks while the negative region in the southern part corresponds to low density sediments. The regional and local isostatic maps with different cut-off wavelengths reflect changes in anomalies corresponding to different types of sedimentary rocks. The general trends of faults in the Chesire basin are shown in the total horizontal derivative map of the Bouguer gravity values. Most of the major faults found in the southern part of the study area are trending in NW-SE and NE-SW directions. The less dominant faults are found in the western and eastern parts with N-S trending faults while in the northern and southern part are trending E-W. The 2D modeling shows the estimated depth to limestone basement of about 3736 m below the sandstone and mudstone.

Shafie, Nadiah Hanim; Hamzah, Umar; Samsudin, Abdul Rahim

2014-09-01

75

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

SciTech Connect

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.

Dean, J.S. (Advantage Resources, Denver, CO (United States)); Wilson, J.T.; Mainzer, G.F. (Anderman-Smith, Denver, CO (United States)); Escobar, F.; Aguirre, G. (ENAP, Punta Arenas (Chile))

1993-02-01

76

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

PubMed Central

Six-year (2005–2010) evolution of water chemistry (Cl?, NO3?, SO42?, HCO3?, Na+, K+, Ca2+ and Mg2+) and their interactions with morphological properties (i.e., slope and area), land cover, and hydrological seasonality were examined to identify controlling factors and processes governing patterns of stream water quality in the upper Han River, China. Correlation analysis and stepwise multiple regression models revealed significant correlations between ions (i.e., Cl?, SO42?, Na+ and K+) and land cover (i.e., vegetation and bare land) over the entire catchment in both high- and low-flow periods, and in the buffer zone the correlation was much more stronger in the low-flow period. Catchment with steeper slope (>15°) was negatively correlated with major ions, largely due to multicollinearity of basin characteristics. Land cover within the buffer zone explained slightly less of major elements than at catchment scale in the rainy season, whereas in the dry season, land cover along the river networks in particular this within 100 m riparian zone much better explained major elements rather than this over the entire catchment. Anthropogenic land uses (i.e., urban and agriculture) however could not explain water chemical variables, albeit EC, TDS, anthropogenic markers (Cl?, NO3?, SO42), Na+, K+ and Ca2+ significantly increased during 2005–2010, which was corroborated by principal component analyses (PCA) that indicated anthropogenic inputs. Observations demonstrated much higher solute concentrations in the industrial-polluted river. Our results suggested that seasonal evolution of water quality in combined with spatial analysis at multiple scales should be a vital part of identifying the controls on spatio-temporal patterns of water quality. PMID:23349700

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

2013-01-01

77

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

(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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

78

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

USGS Publications Warehouse

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.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

79

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

USGS Publications Warehouse

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.

McCarthy, Kathleen A.; Johnson, Henry M.

2009-01-01

80

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

USGS Publications Warehouse

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

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

81

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

USGS Publications Warehouse

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

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

2003-01-01

82

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

NASA Astrophysics Data System (ADS)

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

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

2002-12-01

83

High frequency variations of water flux and sediment discharge during the Little Ice Age (1586–1725 AD) in the Rhône Delta (Mediterranean France). Relationship to the catchment basin  

Microsoft Academic Search

During the 17th and 18th centuries, the Rhône delta recorded high frequency fluctuations in water and sediment influx. These variations resulted from the drastic climatic changes that took place during the Little Ice Age, which were intensified by dense land settlement in the catchment basin. The use of complementary types of information (iconographic and textual archives, photo-interpretation of traces of

G. Arnaud-Fassetta; M. Provansal

1999-01-01

84

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

SciTech Connect

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

Not Available

1988-01-01

85

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

SciTech Connect

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.

Loehle, C; Gladden, J

1988-01-28

86

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)

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.

Nobert, Joel; Mugo, Margaret; Gadain, Hussein

87

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

PubMed

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. PMID:25607670

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

2015-01-01

88

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)

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

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

2010-05-01

89

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

90

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

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

91

Controls on hydrologic partitioning: A comparative hydrology study across sub-catchments in a mountain headwater basin  

NASA Astrophysics Data System (ADS)

Headwater streams are the most abundant portion of the river network but the least monitored. As such, we have a limited understanding of headwater stream behaviors and how they are influenced by watershed properties such as topography, geology, and vegetation. Given the lack of runoff monitoring within headwater streams, improving an understanding of how catchment properties influence hydrologic behavior is necessary for transferring information from instrumented areas to ungauged sites. We utilize this concept to understand physical controls on similarities and differences in hydrologic behavior for five adjacent sub-catchments located in the Tenderfoot Creek Experimental Forest in central Montana with variable topographies and vegetative cover. We use an uncalibrated, distributed, physically-based watershed model, the Distributed Hydrology-Soil-Vegetation Model (DHSVM) combined with global, variance-based sensitivity analysis to investigate physical controls on a range of model-predicted hydrologic behavior (i.e. states) across multiple time scales. We implement comparative hydrology to improve our understanding of headwater watershed runoff behavior within this framework by directly relating physical properties of a given catchment to process-based predictions of hydrologic behavior. We find that across different hydrologic fluxes, including streamflow, evapotranspiration, and snow water equivalent change, only a few vegetation and soil parameters control the variability in hydrologic behavior for all sub-catchments. These controls are similar at the annual and weekly scale, though parameter influence varies seasonally from wet to dry periods. Three of the five watersheds exhibited different controls on hydrologic behavior, likely resulting from past vegetation treatments and differing surficial geology within these sub-watersheds. This framework has strong potential to inform how similarities and differences in headwater watershed characteristics can influence variability in spatially and temporally varying hydrologic behavior. We ultimately demonstrate that the influences of soil and vegetation across headwater watersheds vary, using a modeling framework to understand physical controls on hydrologic behavior at a high resolution. We suggest that this approach can enhance estimation of controls on headwater watershed behavior at unmonitored sites.

Kelleher, C.; Wagener, T.; McGlynn, B. L.

2013-12-01

92

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)

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

Magombeyi, Manuel S.; Taigbenu, Akpofure E.

93

Climate change impact on water and salt balances: an assessment of the impact of climate change on catchment salt and water balances in the Murray-Darling Basin, Australia  

Microsoft Academic Search

Climate change has potentially significant implications for hydrology and the quantity and quality of water resources. This\\u000a study investigated the impacts of climate change and revegetation on water and salt balance, and stream salt concentration\\u000a for catchments within the Murray-Darling Basin, Australia. The Biophysical Capacity to Change model was used with climate\\u000a change scenarios obtained using the CSIRO DARLAM 125

Jenet Austin; Lu Zhang; Roger N. Jones; Warrick Dawes; Peter Hairsine

2010-01-01

94

Isotopic time-series partitioning of streamflow components in wetland-dominated catchments, lower Liard River basin, Northwest Territories, Canada  

Microsoft Academic Search

The distribution of stable water isotopes provides valuable insight into runoff generation processes in subarctic wetland regions of the Mackenzie River basin, a major freshwater contributor to the Arctic Ocean and the focus of intensive hydrological research as part of Canada's contribution to the Global Energy and Water Cycle Experiment (GEWEX). This article describes a streamflow hydrograph separation analysis carried

Natalie A. St Amour; John J. Gibson; Thomas W. D. Edwards; Terry D. Prowse; Alain Pietroniro

2005-01-01

95

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

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

96

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

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).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

97

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

USGS Publications Warehouse

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:

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

2012-01-01

98

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

SciTech Connect

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

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

1986-05-01

99

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

SciTech Connect

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.

Hao, Y; Wolery, T; Carroll, S

2009-04-30

100

A comparative analysis of groundwater recharge estimates from three major methods: An analysis of subsurface recharge in the Nabogo sub-catchment of the White Volta Basin, Northern Ghana  

NASA Astrophysics Data System (ADS)

Groundwater recharge in the Nabogo sub-catchment of the White Volta Basin is assessed using three main methods: the water table fluctuations method, baseflow recession method, and chloride mass balance approach. The objective is to quantify the relative proportions of direct vertical infiltration and percolation of rainwater in the area and subsurface flows in determining the total groundwater recharge in the basin. Groundwater resources development for commercial irrigation activities is an essential aspect of the livelihoods of communities living within the catchments of the Volta Basin. A comprehensive assessment of the recharge component of groundwater budgets in the basin is critical towards determining optimal abstraction rates in order to ensure resource sustainability and ecological integrity. This will form the basis for quantifying abstraction rates that are permissible to support large scale irrigation activities in the basin. The presence and thickness of the clay layer in the unsaturated zone serves to limit vertical infiltration of rainwater, and thus reduce vertical groundwater recharge in the area. In this study, the chloride mass balance technique, supported by the analysis of stable isotope signatures, has been used to estimate the vertical groundwater recharge and its spatial pattern of distribution in the area. The water table fluctuations technique and base flow recession method are then used to estimate total groundwater recharge in the basin. It is then possible to quantify the relative contributions of subsurface flows in the groundwater recharge in the basin. Temporal variations in groundwater recharge in the area are examined from time series of estimates from the baseflow recession technique. The results will assist in assessing the short term impacts of rainfall variability on groundwater budgets in the area.

Fynn, O. F.; Yidana, S. M.; Alo, C. A.; Mensah, F. O.

2013-12-01

101

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

NASA Astrophysics Data System (ADS)

Water management in mining environments is a major challenge of the mining projects. In New Caledonia large areas have been excavated for Nickel mining since the end of the 19th century. In the past, the bad management of the water and coarse sediments left scars in the landscape and management problems in the channel reaches downstream. Nowadays, open mining techniques no longer yield coarse material out of the mining areas but the management of water and fine sediment remains a difficult question as the suspended sediments reach the very fragile environment of the lagoon. In addition, in many areas, it threatens human activities in the downstream rivers. In order to quantify and understand the formation of runoff, erosion and sediment transport in small mining watersheds the "Hydromine" project was initiated in 2008 by the New Caledonia government (DAVAR) with the collaboration of the University of New Caledonia (UNC) and later with the scientific support of Irstea Grenoble. The questions addressed by this project are: - What is the response (water and sediments) of a mining watershed to a rainfall input? - What factors control this response? - What are the processes involved? And which are dominant in the various hydrometeorological situations? - What are the characteristics of the transported materials? - What is the efficiency of mitigation works in the mining area? Two small embedded catchments (0.09 and 0.30 km²) are monitored for measuring rainfall, runoff and fine sediment transport in the mining area of Poro, East cost of New Caledonia. Elevation ranges from 197 to 366 m.a.s.l. The slope are steep (36 % in average but locally up to 130%) and the vegetation cover is very low (20% for the larger basin, 0% for the headwater basin). Rainfall-runoff and discharge-sediment concentration (SSC) relationship were analysed at the event and annual time scale. As a result, we pointed out the main factors that influence the response of the basins to a rainfall event: rainfall depth, rainfall intensity in fifteen minutes and in two hours, peak discharge, runoff coefficient, dry time duration before the event and flood duration. The calculation of suspended sediment yield (SSY) at different time scales gives an evaluation of the pollution delivered to the creeks and lagoon and of the water management and sediment trap efficiency. An extreme rainfall event (December 25th, 2011) of 500 mm in 26 hours yielded downstream more suspended sediment than all the floods of the previous monitored period. This highlights the threshold effects in runoff and erosion response in these open mining areas.

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

2014-05-01

102

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

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.

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

2012-01-01

103

Relative weathering intensity of calcite versus dolomite in carbonate-bearing temperate zone watersheds: Carbonate geochemistry and fluxes from catchments within the St. Lawrence and Danube river basins  

NASA Astrophysics Data System (ADS)

Calcite and dolomite solubilities in open weathering environments are proportional to pCO2 and inversely proportional to temperature, and dolomite solubility is progressively greater than calcite below 25°C. The continent-scale weathering budget reveals the significance of the Northern Hemisphere (NH) to globally integrated riverine fluxes of Ca2+, Mg2+, and HCO3-. The NH contributes 70% of the global HCO3- flux while only 54% of the riverine discharge. We present results of a comparative hydrogeochemical study of carbonate mineral equilibria and weathering fluxes in two NH carbonate-rich river basins. Surface water geochemistry and discharge were determined for headwater streams in Michigan and Slovenia within the St. Lawrence and Danube river basins. Michigan watersheds are established atop carbonate-bearing glacial drift deposits derived from erosion of Paleozoic strata with thick soil horizons (100-300 cm). Slovenia watersheds drain Mesozoic bedrock carbonates in alpine and dinaric karst environments with thin soil horizons (0-70 cm). Carbonate weathering intensity is a parameter that normalizes river runoff and HCO3- concentration to catchment area (meq HCO3- km-2 s-1), summing calcite and dolomite contributions, and is used to gauge the effects of climate, land use, and soil thickness on organic-inorganic carbon processing rates. Importantly, Michigan riverine discharge is one-tenth of Slovenian rivers, providing the opportunity to evaluate the kinetics of carbonate mineral equilibration. The study rivers are HCO3- - Ca2+ - Mg2+ waters, supersaturated for calcite at pCO2 values in excess of the atmosphere. As discharge varies, HCO3- concentrations differ by less than 20% for any location, and Mg2+/Ca2+ remains relatively fixed for Michigan (0.5) and Slovenia streams (0.4), requiring that dolomite dissolution exceed calcite on a mole basis. The ability of calcite and dolomite dissolution to keep pace with increased discharge indicates carbonate weathering is limited only by water flux and temperature-dependent solubility in these watersheds. Carbonate weathering intensity in Michigan and Slovenia exceeds the world average by factors between 2 and 20, and dolomite weathering intensity, estimated from riverine Mg2+ fluxes, exceeds the world average by factors between 2 and 15. Thus global fluxes of carbonate-related weathering products appear heavily skewed toward carbonate-bearing environments at higher latitudes with relatively low mean annual temperatures and high discharge.

Szramek, Kathryn; McIntosh, Jennifer C.; Williams, Erika L.; Kanduc, Tjasa; Ogrinc, Nives; Walter, Lynn M.

2007-04-01

104

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

SciTech Connect

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.

Harmsen, S.C.

1994-06-01

105

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

PubMed

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

Hur, Jin; Jung, Myung Chae

2009-06-01

106

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

NASA Technical Reports Server (NTRS)

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.

Frey, H. V.

2012-01-01

107

Preliminary results of seismic structures in the central basin of South China Sea  

NASA Astrophysics Data System (ADS)

The detailed deep seismic structure of spreading ridge in the central oceanic basin contains key informations of formation and evolution processes, which provides a solid foundation for discussion of formation and evolution 'framework' and deep geodynamics mechanism of the South China Sea (SCS). Three-dimensional (3D) Ocean Bottom Seismometer (OBS) survey was carried out for the first time which covered the central relic spreading ridge and Zhenbei-Huangyan volcanic chain. The comprehensive seismic record sections of 39 OBSs have recorded a few of clear and reliable P-wave seismic phases, such as Pg, Pn and PmP. These seismic arrivals provide strong constrains for the modelling of detailed 2D and 3D velocity structures. Here we will present the preliminary 2D and 3D results to discuss the nature of the oceanic crust near the central spreading ridge and genetic relationship between the magma chambers beneath the spreading ridge and the later volcanic chains. This research was granted by the Natural Science Foundation of China ( 91028002, 41176053, 41076029).

Zhao, M.; Qiu, X.; Wang, J.; He, E.; Zhang, J.

2013-12-01

108

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

NASA Astrophysics Data System (ADS)

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.

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

1995-12-01

109

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

SciTech Connect

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.

Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

1997-04-28

110

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

NASA Astrophysics Data System (ADS)

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

Hlavá?ová, I.; Halounová, L.; Svobodová, K.

2012-07-01

111

Sediments in urban river basins: identification of sediment sources within the Lago Paranoá catchment, Brasilia DF, Brazil - using the fingerprint approach.  

PubMed

The development of effective sediment management strategies is a key requirement in tropical areas with fast urban development, like Brasilia DF, Brazil, because of the limited resources available. Accurate identification and management of sediment sources areas, however, is hampered by the dearth of reliable information on the primary sources of sediment. Few studies have attempted to quantify the source of sediment within fast urbanizing, mixed used, tropical catchments. In this study, statistically verified composite fingerprints and a multivariate mixing model have been used to identify the main land use specific sources of sediment deposited in the artificial Lago Paranoá, Central Brazil. Because of the variability of urban land use types within the Lago Paranoá sub-catchments, the fingerprinting approach was additionally undertaking for the Riacho Fundo sub-catchment. The main contributions from individual source types (i.e. surface materials from residential areas, constructions sites, road deposited sediment, cultivated areas, pasture, farm tracks, woodland and natural gullies) varied between the whole catchment and the Riacho Fundo sub-catchment, reflecting the different proportions of land uses. The sediments deposited in the silting zones of the Lago Paranoá originate largely from urban sources (85 ± 4%). Areas with (semi-) natural vegetation and natural gullies contribute 10 ± 2% of the sediment yield. Agricultural sites have only a minor sediment contribution of about 5 ± 4% within the whole catchment. Within the Riacho Fundo sub-catchment there is a significant contribution from urban (53 ± 4%) source, such as residential areas with semi-detached housings (42 ± 3%) with unpaved roads (12 ± 3%) and construction sites (20 ± 3%) and agricultural areas (31 ± 2%). The relative contribution from land use specific sources to the sediment deposition in the silting zone of the Lago Paranoá demonstrated that most of the sediment is derived from sites with high anthropogenic impact. PMID:23933453

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

2014-01-01

112

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

PubMed

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

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

2010-11-01

113

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

NASA Astrophysics Data System (ADS)

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

Acks, R.; Kraus, M. J.

2012-12-01

114

A preliminary study of oasis evolution in the Tarim Basin, Xinjiang, China  

Microsoft Academic Search

The causes of oasis evolution in the Tarim Basin of north-west China are discussed. Climate change and human activities play different roles in oasis evolution on different temporal scales. The impacts of climate change on oasis evolution are macroscopic and continuous, while the influences of human activities are local and disconnected.The climate of the Tarim Basin, since the late Pleistocene,

Zhang Hong; Wu Jian-Wei; Zheng Qiu-Hong; Yu Yun-Jiang

2003-01-01

115

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

USGS Publications Warehouse

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.

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

2000-01-01

116

Afforestation using micro-catchment water harvesting system with microphytic crust treatment on semi-arid Loess Plateau: A preliminary result  

Microsoft Academic Search

Water harvesting is one of main measures to solve water shortage resulting from less precipitation and erratically seasonal\\u000a distribution in arid and semi-arid areas. Different types of anti-infiltration treatments including mechanical and chemical\\u000a to micro-catchment and their runoff efficiencies had been reported. This paper, through 5 years experiment from 1992 to 1996,\\u000a is aimed at studying the impacts of microcatchment

Yang Xiao-hui; Wang Ke-qin; Wang Bin-rui; Yu Chun-tang

2005-01-01

117

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

NASA Astrophysics Data System (ADS)

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 isotopes during several controlled reservoir releases in the basin. The application of high resolution sampling of stable water isotopes employing a portable laser spectroscope is foreseen in this context.

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

2013-04-01

118

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

SciTech Connect

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

Gan, T.Y. [Univ. of Alberta, Edmonton (Canada); Ahmad, Z. [Chasma Hydropower Project, Lahore (Pakistan)

1997-12-31

119

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

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.

Taha, Haider

2001-01-01

120

Characterizing chromophoric dissolved organic matter in Lake Tianmuhu and its catchment basin using excitation-emission matrix fluorescence and parallel factor analysis.  

PubMed

Chromophoric dissolved organic matter (CDOM) is an important optically active substance that transports nutrients, heavy metals, and other pollutants from terrestrial to aquatic systems and is used as a measure of water quality. To investigate how the source and composition of CDOM changes in both space and time, we used chemical, spectroscopic, and fluorescence analyses to characterize CDOM in Lake Tianmuhu (a drinking water source) and its catchment in China. Parallel factor analysis (PARAFAC) identified three individual fluorophore moieties that were attributed to humic-like and protein-like materials in 224 water samples collected between December 2008 and September 2009. The upstream rivers contained significantly higher concentrations of CDOM than did the lake water (a(350) of 4.27±2.51 and 2.32±0.59 m(-1), respectively), indicating that the rivers carried a substantial load of organic matter to the lake. Of the three main rivers that flow into Lake Tianmuhu, the Pingqiao River brought in the most CDOM from the catchment to the lake. CDOM absorption and the microbial and terrestrial humic-like components, but not the protein-like component, were significantly higher in the wet season than in other seasons, indicating that the frequency of rainfall and runoff could significantly impact the quantity and quality of CDOM collected from the catchment. The different relationships between the maximum fluorescence intensities of the three PARAFAC components, CDOM absorption, and chemical oxygen demand (COD) concentration in riverine and lake water indicated the difference in the composition of CDOM between Lake Tianmuhu and the rivers that feed it. This study demonstrates the utility of combining excitation-emission matrix fluorescence and PARAFAC to study CDOM dynamics in inland waters. PMID:21840562

Zhang, Yunlin; Yin, Yan; Feng, Longqing; Zhu, Guangwei; Shi, Zhiqiang; Liu, Xiaohan; Zhang, Yuanzhi

2011-10-15

121

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)

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 basement, for example, the upper courses of several major West African rivers (Senegal, Niger, Bani, and Volta).

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

122

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

USGS Publications Warehouse

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

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

1980-01-01

123

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

SciTech Connect

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.

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

2006-03-17

124

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

USGS Publications Warehouse

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)

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

1981-01-01

125

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

126

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

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

127

Effects of the catchment runoff coefficient on the performance of TOPMODEL in rainfall-runoff modelling  

Microsoft Academic Search

Effects of the catchment runoff coefficient on the performance of TOPMODEL in simulating catchment rainfall-runoff relationships are investigated in this paper, with an aim to improve TOPMODEL's simulation efficiency in catchments with a low runoff coefficient. Application of TOPMODEL in the semi-arid Yihe catchment, with an area of 2623 km2 in the Yellow River basin of China, produced a Nash-Sutcliffe

Lihua Xiong; Shenglian Guo

2004-01-01

128

Hydrologic comparison between a lowland catchment (Kielstau, Germany) and a mountainous catchment (XitaoXi, China) using KIDS model in PCRaster  

NASA Astrophysics Data System (ADS)

The KIDS model (Kielstau Discharge Simulation model) is a simple rainfall-runoff model developed originally for the Kielstau catchment. To extend its range of application we applied it to a completely different catchment, the XitaoXi catchment in China. Kielstau is a small (51 km2) lowland basin in Northern Germany, with large proportion of wetland area. And XitaoXi is a mesoscale (2271 km2) mountainous basin in the south of China. Both catchments differ greatly in size, topography, landuse, soil properties, and weather conditions. We compared two catchments in these features and stress on the analysis how the specific catchment characteristics could guide the adaptation of KIDS model and the parameter estimation for streamflow simulation. The Nash and Sutcliffe coefficient was 0.73 for Kielstau and 0.65 for XitaoXi. The results suggest that the application of KIDS model may require adjustments according to the specific physical background of the study basin.

Zhang, X.; Hörmann, G.; Fohrer, N.

2009-08-01

129

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

130

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

NASA Astrophysics Data System (ADS)

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.

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

2004-12-01

131

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)

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

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

2013-04-01

132

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

USGS Publications Warehouse

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.

Phelps, Geoffrey A.; Graham, Scott E.

2002-01-01

133

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

PubMed

Soil beneath a stormwater infiltration basin receiving runoff from a 23 ha predominantly residential watershed in north-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 an innovative stormwater infiltration basin utilizing nutrient reduction and flood control sub-basins. Comparison of nitrate/chloride (NO(3)(-)/Cl(-)) ratios for the shallow groundwater indicates that prior to using BAM, NO(3)(-) concentrations were substantially influenced by nitrification or variations in NO(3)(-) input. In contrast, for the new basin utilizing BAM, NO(3)(-)/Cl(-) ratios indicate minor nitrification and NO(3)(-) 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 that NO(3)(-) 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 the 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 (PO(4)(3-)) 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 PO(4)(3-)/Cl(-) ratios for shallow groundwater indicate predominantly minor increases and decreases in PO(4)(3-) with the exception of one summer sample that indicated a 50% loss. Differences in nutrient variations between the unsaturated zone and shallow groundwater may be the result of the intensity and duration of nutrient removal processes and mixing ratios with water that had undergone little biogeochemical transformation. Observed nitrogen and phosphorus losses demonstrate the potential, as well as the future research needs to improve performance, of the innovative stormwater infiltration basin using BAM for providing passive, economical, stormwater nutrient-treatment technology to support green infrastructure. PMID:22742948

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

2012-08-15

134

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

NASA Astrophysics Data System (ADS)

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

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

135

Managing the impact of gold panning activities within the context of integrated water resources management planning in the Lower Manyame Sub-Catchment, Zambezi Basin, Zimbabwe  

NASA Astrophysics Data System (ADS)

Riverbed alluvial gold panning activities are a cause for degradation of river channels and banks as well as water resources, particularly through accelerated erosion and siltation, in many areas of Zimbabwe. The lower Manyame sub-catchment located in the Northern part of the country is one such area. This study analysed the implications of cross-sectoral coordination of the management of panning and its impacts. This is within the context of conflicts of interests and responsibilities. A situational analysis of different stakeholders from sectors that included mining, environment, water, local government and water users who were located next to identified panning sites, as well as panners was carried out. Selected sites along the Dande River were observed to assess the environmental effects. The study determined that all stakeholder groups perceived siltation and river bank degradation as the most severe effect of panning on water resources, yet there were divergent views with regards to coordination of panning management. The Water Act of 1998 does not give enough power to management institutions including the Lower Manyame Sub-catchment Council to protect water resources from the impacts of panning, despite the fact that the activities affect the water resource base. The Mines and Minerals Act of 1996 remains the most powerful legislation, while mining sector activities adversely affect environmental resources. Furthermore, complexities were caused by differences in the definition of water resources management boundaries as compared to the overall environmental resources management boundaries according to the Environmental Management Act (EMA) of 2000, and by separate yet parallel water and environmental planning processes. Environmental sector institutions according to the EMA are well linked to local government functions and resource management is administrative, enhancing efficient coordination.

Zwane, Nonhlanhla; Love, David; Hoko, Zvikomborero; Shoko, Dennis

136

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

NASA Astrophysics Data System (ADS)

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

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

1984-02-01

137

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

NASA Astrophysics Data System (ADS)

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 "Ba?a 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 "Ba?a 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.

Opr?kal, P.; Gale, L.; Kolar-Jurkovšek, T.; Roži?, B.

2012-04-01

138

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

SciTech Connect

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.

Mills, R.A.; Barton, R. [True Oil Co., Casper, WY (United States)

1996-10-01

139

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

PubMed

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

Kumbar, Suresh M; Ghadage, Abhijit B

2014-11-01

140

Modelling differential catchment response to environmental change  

NASA Astrophysics Data System (ADS)

The CAESAR (Cellular Automaton Evolutionary Slope And River) model is used to demonstrate significant differences in coarse sediment transfer and alluviation in medium sized catchments when responding to identical Holocene environmental changes. Simulations for four U.K. basins (the Rivers Swale, Ure, Nidd and Wharfe) shows that catchment response, driven by climate and conditioned by land cover changes, is synchronous but varies in magnitude. There are bursts of sediment transfer activity, generally of rapid removal but with some sediment accumulation 'spikes', with longer periods of slow removal or accumulation of sediment in different valley reaches. Within catchments, reach sensitivity to environmental change varies considerably: some periods are only recorded in some reaches, whilst higher potential sensitivity typically occurs in the piedmont areas of the catchments modelled here. These differential responses appear to be highly non-linear and may relate to the passage of sediment waves, by variable local sediment storage and availability, and by large- and small-scale thresholds for sediment transfer within each catchment. Differential response has major implications for modelling fluvial systems and the interpretation of field data. Model results are compared with the record of dated alluvial deposits in the modelled catchments.

Coulthard, T. J.; Lewin, J.; Macklin, M. G.

2005-07-01

141

Magnetic Fabric of the Itararé Group, Paraná Basin Brazil: Preliminary Results  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

142

Preliminary results of imaging spectroscopy of the Humorum Basin region of the moon  

NASA Technical Reports Server (NTRS)

Imaging spectroscopy of the lunar surface was carried out using a CCD spectrograph employed as an imaging spectrometer at the University of Hawaii 2.24-m telescope at Mauna Kea Observatory. A portion of the Humorum multiringed impact basin was observed, yielding an imaging spectroscopic dataset consisting of approximately 400,000 spectra covering the wavelength region 0.7-0.98 microns at a spectral resolution of 200 (lambda/Delta-lambda). Results of this analysis included (1) identifying craters and other explosures of highland material within the bounds of Mare Humorum, (2) identifying craters in the highlands adjacents to Mare Humorum that excavate buried mare basalt, and (3) identifying two spectral units in the highlands that likely represent compositional units. The region is shown to be extremely diverse spectrally and demonstrates the ability of imaging spectroscopy to enable a qualitative improvement in the ability to identify and map compositional units.

Lucey, P. G.; Bruno, B. C.; Hawke, B. R.

1991-01-01

143

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

NASA Astrophysics Data System (ADS)

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

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

144

Preliminary data on the feeding habits of the freshwater stingrays Potamotrygon falkneri and Potamotrygon motoro (Potamotrygonidae) from the Upper Paraná River basin, Brazil  

Microsoft Academic Search

Silva, T.B. & Uieda, V.S. Preliminary data on the feeding habits of the freshwater stingrays Potamotrygon falkneri and Potamotrygon motoro (Potamotrygonidae) from the Upper Paraná River basin, Brazil. Biota Neotrop. Jan\\/Apr 2007 vol. 7, no. 1 http:\\/\\/www.biotaneotropica.org.br\\/v7n1\\/pt\\/abstract?article+bn02007012007 ISSN 1676-0603. Stingrays of the Potamotrygonidae family are a singular group of Neotropical ichthyofauna. Although ancient reports exist about the group, there are

Thiago Buosi Silva; Virgínia Sanches Uieda

2007-01-01

145

Reservoir property estimation in Pohang Basin, South Korea for the preliminary CO2 storage prospect  

NASA Astrophysics Data System (ADS)

Geological CO2 storage draws a great attention globally and South Korea also look for proper storage sites to reduce CO2 emission. The Pohang Basin area, located at the southeastern part of Korea, is regarded as a good candidate for CO2 storage, since the basin is believed to have good sand intervals, and there are various CO2 sources, such as a steel mill and a car factory around the area. However, there are not many geophysical data (core, logs, seismic, etc.) available since the area is highly industrialized and the target site is located offshore. There are a few well logs sparsely located, and core data are not many either since the target formation is semi- to unconsolidated clastics. To overcome these difficulties, we firstly go back to regional geology and determine the regional 3D distribution of target formation. Then, we obtain onshore outcrop samples from the same target formation to compliment scarce core data. The core and outcrop samples are not well-consolidated, which makes lab measurements highly difficult. We adopt a computational rock physics method, which estimates porosity and permeability on 3D microstructures statistically reconstructed from thin section images. The average values of porosity and permeability of outcrop samples are 25% and 1,000mD, and those from one core data 17% and 100mD, respectively. Other cores from the same formation do not give any significant permeability values. Thus, we categorize the formation into two subgroups, good and bad. Next, we visit well-log data and categorize intervals into two subgroups, and apply the our computation results to the good group. Finally, we can give maps of reservoir properties for the target formation. Although we can give only approximate values/relations of reservoir properties for good interval, it helps evaluate overall prospect of the target formation. Acknowledgements: This research was supported by the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Trade, Industry and Energy of Korea (GP2012-030).

Han, J.; Keehm, Y.

2013-12-01

146

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

USGS Publications Warehouse

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.

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

1994-01-01

147

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

USGS Publications Warehouse

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.

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

148

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

PubMed

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. PMID:25140502

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

2014-09-01

149

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

USGS Publications Warehouse

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).

Grant, R. Stephen; Goddard, Gerald

1980-01-01

150

Modeling the Caspian Sea and its catchment area using a coupled regional atmosphere-ocean model (RegCM-ROMS): model design and preliminary results  

NASA Astrophysics Data System (ADS)

We describe the development of a coupled regional atmosphere-ocean model (RegCM-ROMS) and its implementation over the Caspian Sea basin. The coupled model is run for the period 1999-2008 (after a spin up of 4 yr) and it is compared to corresponding stand alone model simulations and a simulation in which a distributed 1d lake model is run for the Caspian Sea. All model versions show a good performance in reproducing the climatology of the Caspian Sea basin, with relatively minor differences across them. The coupled ROMS produces realistic, although somewhat overestimated, lake surface temperatures (LSTs), with a considerable improvement compared to the use of the simpler coupled lake model. Simulated near surface salinity and sea currents are also realistic, although the upwelling over the eastern coastal regions is underestimated. The distribution of sea ice over the shallow northern shelf of the Caspian Sea and its seasonal evolution are well reproduced. ROMS also calculates the Caspian Sea Level (CSL), showing that for the present experiment excessive evaporation over the lake area leads to a drift in estimated CSL. Despite this problem which requires further analysis due to many uncertainties in the estimation of CSL, overall the coupled RegCM-ROMS system shows encouraging results in reproducing both the climatology of the region and the basic characteristics of the Caspian Sea.

Turuncoglu, Ufuk; Giuliani, Graziano; Elguindi, Nellie; Giorgi, Filippo

2013-04-01

151

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

152

Magnetic Fabric of the Aquidauana Formation, western border of the Paraná Basin Central Brazil: Preliminary Results  

NASA Astrophysics Data System (ADS)

The glaciogenic sedimentation (Carboniferous-Permian) on the western border of the Paraná Basin is represented by reddish-brown strata of the Aquidauana Formation. Subsurface data suggest that this Formation is equivalent to the Itararé Group, which contains the most extensive lithological record of Gondwana glaciation in the world. The Aquidauna Formation crops out as an NNE-SSW-oriented elongated belt at the western portion of the Maracaju-Campo Grande Plateau in Mato Grosso do Sul State (Central part of Brazil), and extents to the north up to Mato Grosso and Goias states. This Formation is composed of a variety of types of sandstones, siltites, and mudstones. The magnetic studies were performed on sites of undeformed reddish-brown sandstones, siltites, and mudstones, which crop out mainly in Mato Grosso do Sul State. Magnetic fabrics were determined on oriented cylindrical specimens (2.54 cm x 2.2 cm) using anisotropy of low-field magnetic susceptibility (AMS). Rock-magnetic analyses reveal that both magnetite and hematite are the main magnetic minerals in the majority of the analyzed sites. Regarding the eingenvector orientations, the sites usually gave good results. The analysis at the individual-site scale defines two AMS fabric types. The first type shows Kmin perpendicular to the bedding plane, while Kmax and Kint are scattered within the bedding plane itself. This fabric is usually interpreted as primary (sedimentary-compactional), typical of undeformed sediments and is dominant among the sites. The second type shows good clustering of the AMS principal axes with Kmin still either perpendicular or sub-perpendicular to the bedding plane. This fabric type could be interpreted as a combination of sedimentary-compactional and tectonic contributions if some strain markers or evidence for tectonic deformation had been found in the studied area. On the other hand, the tight Kmax grouping in this fabric type could be explained by the action of currents since they cause Kmax to be aligned sub-parallel to the paleocurrent direction.

Raposo, M. B.

2013-05-01

153

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

USGS Publications Warehouse

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

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

1998-01-01

154

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

NASA Astrophysics Data System (ADS)

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

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

155

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

PubMed

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. PMID:11383332

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

2001-01-01

156

Modeling of facade leaching in urban catchments  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

157

Design and development of a wireless sensor network to monitor snow depth in multiple catchments in the American River basin, California: hardware selection and sensor placement techniques  

NASA Astrophysics Data System (ADS)

A 100-node wireless sensor network (WSN) was designed for the purpose of monitoring snow depth in two watersheds, spanning 3 km2 in the American River basin, in the central Sierra Nevada of California. The network will be deployed as a prototype project that will become a core element of a larger water information system for the Sierra Nevada. The site conditions range from mid-elevation forested areas to sub-alpine terrain with light forest cover. Extreme temperature and humidity fluctuations, along with heavy rain and snowfall events, create particularly challenging conditions for wireless communications. We show how statistics gathered from a previously deployed 60-node WSN, located in the Southern Sierra Critical Zone Observatory, were used to inform design. We adapted robust network hardware, manufactured by Dust Networks for highly demanding industrial monitoring, and added linear amplifiers to the radios to improve transmission distances. We also designed a custom data-logging board to interface the WSN hardware with snow-depth sensors. Due to the large distance between sensing locations, and complexity of terrain, we analyzed network statistics to select the location of repeater nodes, to create a redundant and reliable mesh. This optimized network topology will maximize transmission distances, while ensuring power-efficient network operations throughout harsh winter conditions. At least 30 of the 100 nodes will actively sense snow depth, while the remainder will act as sensor-ready repeaters in the mesh. Data from a previously conducted snow survey was used to create a Gaussian Process model of snow depth; variance estimates produced by this model were used to suggest near-optimal locations for snow-depth sensors to measure the variability across a 1 km2 grid. We compare the locations selected by the sensor placement algorithm to those made through expert opinion, and offer explanations for differences resulting from each approach.

Kerkez, B.; Rice, R.; Glaser, S. D.; Bales, R. C.; Saksa, P. C.

2010-12-01

158

Stream macroinvertebrate response to catchment urbanisation (Georgia, U.S.A.)  

Microsoft Academic Search

SUMMARY 1. The effects of catchment urbanisation on water quality were examined for 30 streams (stratified into 15, 50 and 100 km2 ±2 5% catchments) in the Etowah River basin, Georgia, U.S.A. We examined relationships between land cover (implying cover and use) in these catchments (e.g. urban, forest and agriculture) and macroinvertebrate assemblage attributes using several previously published indices to

A. H. R OY; A. D. R OSEMOND; J. B. W ALLACE; Owings Mills

2003-01-01

159

Catchment hydro-geomorphological responses to environmental change in the Southern Uplands of Scotland  

Microsoft Academic Search

Lake sediment and geomorphic evidence from the Loch of the Lowes\\/St Mary's Loch basin in the central Southern Uplands of Scotland provide a multiproxy reconstruction of changing sediment availability and transmission through the catchment. Interrogation of magnetic, geochemical and grain size parameters for lake and catchment materials suggests it is possible to identify independent proxies that reflect both supply (availability)

G. C. Foster; R. C. Chiverrell; A. M. Harvey; J. A. Dearing; H. Dunsford

2008-01-01

160

Development and evaluation of a new catchment-scale model of floodplain sedimentation  

Microsoft Academic Search

Fine-sediment storage within floodplain systems typically represents a significant component of the catchment sediment budget and a primary control on sediment-associated nutrient and contaminant fluxes at the basin scale. However, quantitative modeling of floodplain sedimentation within whole catchments represents a significant challenge, not least because hydraulic controls on sediment transport and deposition processes operate at fine spatial scales that cannot

A. P. Nicholas; D. E. Walling; R. J. Sweet; X. Fang

2006-01-01

161

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

SciTech Connect

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

Millings, M.

2013-09-16

162

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

USGS Publications Warehouse

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

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

1976-01-01

163

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

USGS Publications Warehouse

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 Illinois River included in this study was treated as one reach. This stretch of the Illinois River is fully alluvial, with nearly continuous gravel bars flanking the channel. The width of the active channel is confined by the narrow topography of the valley. * The primary human activities that have likely influenced channel condition, bed-material transport, and the extent and area of bars are (1) historical gold mining throughout the basin, (2) historical and ongoing gravel mining from instream sites in the Tidal Reach and floodplain sites such as those in the Lower Applegate River Reach, (3) hydropower and flow control structures, (4) forest management and fires throughout the basin, and (5) dredging. These anthropogenic activities likely have varying effects on channel condition and the transport and deposition of sediment throughout the study area and over time. * Several vertical (aspect) aerial photographs (including the complete coverages of the study area taken in 1995, 2000, 2005, and 2009 and the partial coverages taken in 1967, 1968, 1969, and 1990) are available for assessing long-term changes in attributes such as channel condition, bar area, and vegetation cover. A Light Detection And Ranging (LiDAR) survey performed in 2007-2008 provides 1-m resolution topographic data for sections of the Grants Pass (RKM 178.5-167.6) and Lobster Creek (RKM 17.8-12 and 10-6.7) Reaches and the entire Tidal Reach. * Previous studies provide information for specific locations, including (1) an estimated average annual bed-material load of 76,000 m3 at the former Savage Rapids Dam site (RKM 173.1, Grants Pass Reach), (2) over 490 m of channel shifting from 1965 to 1991 in the Brushy Chutes area (RKM 142-141, Merlin Reach), (3) active sediment transport and channel processes in the Lobster Creek Reach, (4) lateral channel migration in the Tidal Reach, and (5) up to 1.8 m of bar aggradation from the town of Agness (RKM 45.1) to the Rogue River mouth following the flood in water year 1997. * Review of the repeat surveys conducted at the instream gravel-mining sites on Elephant

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

2012-01-01

164

WATER AND SEDIMENT MANAGEMENT FOR THE BLUE NILE BASIN  

Microsoft Academic Search

The sediment yield of rivers is often sensitive to changes in catchments land use and human activities. Such an impact is most likely to be demonstrated at a restricted spatial scale, particularly in headwater catchments. In large river basins such as Nile River Basin, there are needs to study, understand, and quantify the impacts of these modifications on the hydrologic

Tarek Mohamed Abdel-Aziz

2009-01-01

165

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

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).

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

2009-01-01

166

How old is upland catchment water?  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

167

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...

168

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

PubMed

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

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

2015-04-01

169

Comparison of regionalization approaches in parameterizing sediment rating curve in ungauged catchments for subsequent instantaneous sediment yield prediction  

NASA Astrophysics Data System (ADS)

Observations of sediment loading are lacking for rivers in many parts of the world, particularly in developing countries. There is a need for better understanding of what models might be available to offer estimates of sediment yield in such poorly gauged or ungauged areas. Therefore, the aim of this research is to determine an ideal regionalization methodology for estimating sediment rating curves in ungauged catchments for instantaneous suspended sediment yield (SSY) prediction. A comparison of three regionalization approaches (catchment similarity, regression and spatial proximity) was carried out in 16 catchments, in the Lower Mekong Basin, after discarding one with the evidence that the data point is not homogeneous. The highest quality results are provided by the catchment similarity approach in which a single donor catchment was selected in accordance with an optimum catchment similarity index computed by the multidimensional scaling technique. The regression-based approach is intermediate. The sparse network of basin monitoring in the study area does not favor the spatial proximity approach, producing the worst regionalization solution. The overall predictive accuracy was further improved through a combined formulation of catchment similarity and regression. This reveals that different approaches have different advantages and therefore, using only one of them cannot fully encompass a wide range of catchment heterogeneity. Since the ideal regionalization methodology performs satisfactorily in all 16 sites, a regional model with a relatively simple geomorphic framework was established for estimating catchment-scale SSY in ungauged rivers of the basin.

Heng, Sokchhay; Suetsugi, Tadashi

2014-05-01

170

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...

171

HYDROLOGIC CHARACTERISTICS OF A DRAINED TROPICAL PEAT CATCHMENT: RUNOFF COEFFICIENTS, WATER TABLE AND FLOW DURATION CURVES  

Microsoft Academic Search

Reclamation and drainage of peat basin is an important land development in Malaysia. A clear understanding on the hydrologic behavior of a drained peat basin is the essential factor towards an optimal management of the resource. Hydrological data from Madirono peat catchment located in Johor State, Malaysia was collected and used to characterise its hydrologic characteristics. The characterizations were made

AYOB KATIMON; AHMAD KHAIRI; ABD WAHAB

172

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

USGS Publications Warehouse

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

Livingston, Russell K.

1981-01-01

173

Exhumation of the Magallanes foreland basin, Patagonian Andes, Chile (51 °S): Preliminary results from apatite (U-Th)\\/He dating  

Microsoft Academic Search

Deformation of the Magallanes foreland basin and the development and subsequent exhumation of the adjacent fold-and-thrust belt are integral processes that have influenced the modern structure, physiography, and climate of southern Patagonia. Despite recent work documenting these processes, fundamental aspects of the evolution of the Southern Andes remain ambiguous. In this study, apatite (U-Th)\\/He thermochronology documents the youngest stage in

J. C. Fosdick; B. W. Romans; S. M. Hubbard

2006-01-01

174

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

SciTech Connect

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.

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

1984-12-31

175

Comment on "Catchment flow estimation using Artifical Neural Networks in the mountainous Euphrates basin" by A.G. Yilmaz, M.A. Imteaz, G. Jenkins (J. Hydrol. 410 (2011) 134-140)  

NASA Astrophysics Data System (ADS)

SummaryThe studies conducted in the Euphrates Basin draws special attention due to its high snow potential and hydropolitical condition. Snow and hydrometeorological instrumentation has been set up for real time monitoring and data collection in the Upper Euphrates Basin over the past decade. Hydrological modeling studies using satellite snow products have been carried out in the basin for real time runoff forecasting. Moreover, the Upper Euphrates Basin is a pilot basin for several national and international projects on snow hydrology concerning its location and topography. These are the main reasons in writing this comment on the methodology and data used by Yilmaz et al. Yilmaz et al. draw the attention to the ANN which does not require a high level of expertise in successfully identifying the nonlinear hydrological processes. However, ANN modeling should be used with care and enough data including topography and snow data especially when applied in a mountainous snow dominated basin.

?ensoy, Aynur; Ünal ?orman, A.; Arda ?orman, A.

2012-08-01

176

Carbon isotope indicators of catchment vegetation in the Brazilian Amazon  

NASA Astrophysics Data System (ADS)

Paniculate organic carbon (POC) samples from rivers draining wholly forested catchments in the Amazon Basin exhibit carbon isotope values (?13C) of generally between -27 and -30‰. These values are distinct from those of POC from rivers draining nonforested (grassland/woodland) catchments, which are generally higher than -26‰. The difference is due to the presence in the nonforested regions, of grasses which assimilate carbon via the C4 photosynthetic pathway (average ?13C = ˜-13‰), rather than the C3 pathway (average ?13C = ˜-28‰) utilized by forest vegetation, and to negligible utilization of low-?13C respired carbon dioxide in regions of open vegetation. A change in the area of the Basin covered by closed forest will lead to a modification in the carbon isotope composition of exported POC as a result of changing (1) the proportion of C4 carbon in the total biomass (2) the relative proportion of the total POC derived from upstream, high-altitude (Andean) sources, (3) erosion rates, and (4) productivity. All of these factors will tend to reinforce each other in their effect on the carbon isotope composition of POC exported from the Basin, with a decrease in forest area leading to an increase in the ?13C value of POC (and vice versa). There is a sufficient difference between the ?13C values of POC exported from forested and non- forested catchments to elucidate past vegetation and therefore climatic changes in the Amazon Basin (and other tropical river basins), using the ?13C record in POC from either terrestrial or offshore sedimentary sequences. The carbon isotope composition of POC in rivers draining recently deforested regions indicates that the isotopic composition of coarse (>63 ?m) riverine POC will respond to vegetation changes in a catchment within years to decades, whereas the ?13C value of fine-grained (<63 ?m) riverine POC may take longer to respond.

Bird, M. I.; Fyfe, W. S.; Pinheiro-Dick, D.; Chivas, A. R.

1992-09-01

177

The anthropic catchment-ecosystem concept: an Irish example  

SciTech Connect

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.

Phillips-Howard, K.D.

1985-06-01

178

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

USGS Publications Warehouse

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

Palacas, James George

1978-01-01

179

Preliminary results of chronostratigraphic field work, OSL-dating and morphogenetic reconstruction of an alluvial apron at Alborz southern foothill, Damghan basin, Iran  

NASA Astrophysics Data System (ADS)

Here we present preliminary results of a chronostratigraphic study of an alluvial fan in the Damghan Basin, northern Iran. The basin sediments date back to the Mio- and Pliocene and therefore represent the starting point of alluvial fan aggradation. Today, the still active alluvial fans prograde from the Albors Mountain ranges and sit on the older sediment bodies. In this study, our focus is on the late Pleistocene to Holocene alluvial fan sedimentation history. The upper stratigraphy of the alluvial fans and intercalated lake deposits is characterized by six individual layers of gravels and fines, representing six different stratigraphic units. These units are described and classified by detailed geomorphological and stratigraphic mapping. To establish an alluvial fan chronology, six profiles were sampled for OSL dating. As expected, due to the high-energy transport system of alluvial fan aggradation in semi-desert environments, OSL dating of these sediments is challenging due to the problem of insufficient bleaching. Consequently, most of the samples are interpreted as maximum ages. However, the measurements show a consistent internal age structure and the overall OSL-based chronology is in agreement with the age model derived from our geomorphological analysis. As a first interpretation, based on surveyed geomorphological features and chronological analysis, we could identify seven morphodynamic phases, leading to a genetic model of alluvial fan aggradation. The oldest Pleistocene age estimate is derived from a former lake terrace. The following ages represent ongoing lake sediment deposition and the development of a proximal and mid-fan gravel cover. After the youngest lake deposits were accumulated within the Holocene, the lake starts to retreat and small alluvial fans are filling up the former lake bottom. This last sedimentation phase can be divided in at least two sub-phases, probably coupled to a lateral shifting of the active depositional lobe and to the abandonment and shallow incision of mid fan surfaces.

Büdel, Christian; Fuchs, Markus; Majid Padashi, Seyed; Baumhauer, Roland

2014-05-01

180

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

181

Catchment classification based on characterisation of streamflow and precipitation time-series, Part II: Application to ungauged catchments  

NASA Astrophysics Data System (ADS)

One of the primary practical objectives for delineating hydrological homogeneous regions is to assess the membership of ungauged sites, thus inferring indications on the response behaviour of such catchments. An important feature of a cluster analysis aimed at identifying homogeneous clusters is therefore the ability to discriminate between them on the basis of variables that are different from the streamflow signatures, that is, a set of physical and climatic characteristics of the watersheds. The first part of the study (companion presentation: Part I: Classification of streamflow signatures) illustrates a SOM-based approach for catchment grouping on the basis of their hydrological response, through a representation, albeit simplified, of the properties of fine time-scale flow series and in particular of the dynamic components of the hydrometric data. In order to assign ungauged sites to such groups, the catchments are here represented through a parsimonious set of morphometric and pluviometric variables, including also indexes that attempt to synthesize the variability and correlation properties of the precipitation time-series, thus providing information on the type of weather forcing that is specific to each basin. Following a principal components analysis, needed for synthesizing and better understanding the morpho-pluviometric catchment properties, a Discriminant Analysis finally classifies the ungauged catchments, through a leave-one-out cross-validation, to one of the above identified hydrologic response classes. The approach delivers quite satisfactory results for ungauged catchments, since the comparison of the two cluster sets shows an acceptable overlap. Overall results indicate that the inclusion of information on the properties of the fine time-scale streamflow and rainfall time-series may be a promising way for better representing the hydrologic and climatic character of the study catchments.

Toth, Elena

2013-04-01

182

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

NASA Astrophysics Data System (ADS)

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 communication.

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

2010-05-01

183

Hydrological Catchment Similarity Assessment in Geum River Catchments, Korea  

NASA Astrophysics Data System (ADS)

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 clustering analysis of FDC. This study shows a potential of hydrological catchment similarity measures in Korea. It will be used as a starting point for flood predictions at ungauged catchment.

Ko, Ara; Park, Kisoon; Lee, Hyosang

2013-04-01

184

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

SciTech Connect

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.

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

2013-01-30

185

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

SciTech Connect

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.

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

2013-01-01

186

Projected effects of proposed chloride-control projects on shallow ground water; preliminary results for the Wichita River basin, Texas  

USGS Publications Warehouse

The U.S. Army Corps of Engineers ' plan to control the natural chloride pollution in Wichita River basin includes construction of Truscott Brine Lake on a tributary of North Wichita River. In connection with the proposed brine lake, the U.S. Geological Survey was requested to define the existing ground-water conditions in the shallow freshwater system of the project area and to project the postconstruction effects of the proposed lake on the freshwater aquifer. The freshwater aquifer in the project area is a shallow water-table system with relatively freshwater that contains approximately 500-5,000 milligrams per liter of dissolved solids and consists of Permian rocks with very small values of hydraulic conductivity. It overlies a brine system that is even less permeable. Two-dimensional mathematical computer models were developed for aquifer simulation of steady-state conditions in a freshwater system and transient conditions in a brine-freshwater system where density effects of the brine are considered. Main results of the project are: (1) Water-level rises in the aquifer of 5-40 feet would be confined to areas near the proposed dam and along lake shoreline, and (2) migration of saltwater downstream from dam generally would be limited to less than 1 mile and apparently, would not reach equilibrium during the 100-year duration of the project. (USGS)

Garza, Sergio

1983-01-01

187

Uncertainty analysis in model parameters regionalization: a case study involving the SWAT model in Mediterranean catchments (Southern France)  

NASA Astrophysics Data System (ADS)

In this study a method for propagating the hydrological model uncertainty in discharge predictions of ungauged Mediterranean catchments using a model parameter regionalization approach is presented. The method is developed and tested for the Thau catchment located in Southern France using the SWAT hydrological model. Regionalization of model parameters, based on physical similarity measured between gauged and ungauged catchment attributes, is a popular methodology for discharge prediction in ungauged basins, but it is often confronted with an arbitrary criterion for selecting the "behavioral" model parameter sets (Mps) at the gauged catchment. A more objective method is provided in this paper where the transferrable Mps are selected based on the similarity between the donor and the receptor catchments. In addition, the method allows propagating the modeling uncertainty while transferring the Mps to the ungauged catchments. Results indicate that physically similar catchments located within the same geographic and climatic region may exhibit similar hydrological behavior and can also be affected by similar model prediction uncertainty. Furthermore, the results suggest that model prediction uncertainty at the ungauged catchment increases as the dissimilarity between the donor and the receptor catchments increases. The methodology presented in this paper can be replicated and used in regionalization of any hydrological model parameters for estimating streamflow at ungauged catchment.

Sellami, H.; La Jeunesse, I.; Benabdallah, S.; Baghdadi, N.; Vanclooster, M.

2014-06-01

188

What controls inter-basin variation in cold-season river flow recession in permafrost basins in sub-Arctic Siberia?  

NASA Astrophysics Data System (ADS)

Cold-season river discharge during the period of ice cover and snow fall in northern high latitudes, provides a unique window on the role of subsurface hydrology in permafrost settings as direct surface runoff contributions are largely inhibited. Several recent studies have brought to light positive temporal trends in cold-season discharge totals for the past several decades to one century, and have interpreted these trends to reflect permafrost degradation and associated increased subsurface water transport in response to climate warming. While these are significant and compelling findings of hydrological change, there is a clear need to better understand the hydrology of cold-season flow and the discharge-generating processes themselves. We present results of an inter-basin comparison of cold-season (October - April) river flow characteristics for 17 catchments in Siberia that are not disturbed by artifical reservoirs/dam influences. Streamflow data for the period 1980 - 1998 were studied. Flow and recession metrics for each basin and mean annual cold season catchment-averaged drainage depth, CSDD (in mm equivalent water depth) were compared/correlated with various basin attributes in order to evaluate the significance of these attributes as potential controls. Preliminary findings include a marked behavioural distinction between (11) basins on continuous permafrost and (6) basins with reduced permafrost coverage (discontinuous/sporadic). The latter are characterized by slow recession, relatively high discharge in April before spring freshet, and high CSDD values up to about 80 mm corresponding to more than 10% of total annual rainfall. Although positive correlations with several attributes (annual precipitation; peat land fraction) are found, higher abundance of through-taliks and greater active layer depth (ALD) appear to be the most prominent controls of the distinctive behaviour. Cold-season flow behaviour of the (11) basins on continuous permafrost also show conspicuous inter-basin differences, with some rivers exhibiting very fast recession and cessation of flow for 3 to 4 months, while others show strongly reduced, but continuous discharge throughout the cold season. An interesting question is if the latter behaviour signals contributions from intra- and/or sub-permafrost groundwater flow. Comparison with investigated catchment attributes suggests that ALD, soil properties and vegetation cover do not account for these differences, while lake area fraction and peat land fraction may play a role in favouring prolonged cold-season flow, although correlation is weak. It is anticipated that river valley and stream channel characteristics may be important, but this remains to be evaluated.

Kooi, H.; Watson, V.; Bense, V. F.

2012-04-01

189

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

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

190

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

NASA Astrophysics Data System (ADS)

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 the late Holocene (post-3,000 cal yr B.P.). Future research will include analysis of both macro- and micro-charcoal abundances. The charcoal record will augment the suite of data presented here by providing independent evidence of variability in precipitation regimes and drought history. An additional set of cores from a perennial wetland on the eastern edge of the range, Ruby Marsh, will provide a low elevation paleoclimatic counterpoint to this alpine site.

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

2009-12-01

191

Defining prior probabilities for hydrologic model structures in UK catchments  

NASA Astrophysics Data System (ADS)

The selection of a model structure is an essential part of the hydrological modelling process. Recently flexible modeling frameworks have been proposed where hybrid model structures can be obtained by mixing together components from a suite of existing hydrological models. When sufficient and reliable data are available, this framework can be successfully utilised to identify the most appropriate structure, and associated optimal parameters, for a given catchment by maximizing the different models ability to reproduce the desired range of flow behaviour. In this study, we use a flexible modelling framework to address a rather different question: can the most appropriate model structure be inferred a priori (i.e without using flow observations) from catchment characteristics like topography, geology, land use, and climate? Furthermore and more generally, can we define priori probabilities of different model structures as a function of catchment characteristics? To address these questions we propose a two-step methodology and demonstrate it by application to a national database of meteo-hydrological data and catchment characteristics for 89 catchments across the UK. In the first step, each catchment is associated with its most appropriate model structure. We consider six possible structures obtained by combining two soil moisture accounting components widely used in the UK (Penman and PDM) and three different flow routing modules (linear, parallel, leaky). We measure the suitability of a model structure by the probability of finding behavioural parameterizations for that model structure when applied to the catchment under study. In the second step, we use regression analysis to establish a relation between selected model structures and the catchment characteristics. Specifically, we apply Classification And Regression Trees (CART) and show that three catchment characteristics, the Base Flow Index, the Runoff Coefficient and the mean Drainage Path Slope, can be used to predict which model structure is more appropriate. The study constitutes a first step to enhance the choice of model structures in hydrological modeling across regions, with potentially interesting applications for predictions in ungauged basins, that was made possible by the analyses of large datasets.

Clements, Michiel; Pianosi, Francesca; Wagener, Thorsten; Coxon, Gemma; Freer, Jim; Booij, Martijn

2014-05-01

192

The relative influence of climate and catchment properties on hydrological drought  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

193

Runoff predictions in ungauged catchments in southeast Tibetan Plateau  

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

194

Which catchment properties determine runoff behavior in small catchments?  

NASA Astrophysics Data System (ADS)

The complexity of Pleistocene landscape and various anthropogenic influences complicate the classification of runoff characteristics of small catchments in northeast Germany. Such a classification would be of use for scientists and water managers in order to estimate the catchments' vulnerability regarding floods and low flows, transfer results to ungauged catchments as well as planning of measures to adapt to climate change. The objective of our study is the use of dimensional reduction technique solely on discharge time series in order to classify runoff behavior of small catchments (< 500 km2) of Brandenburg, Germany. The study is based on data of daily discharge at 40 gauges from 1991 to 2006. Data was provided by the State Office of Environment, Health and Consumer Protection of the Federal State of Brandenburg. Principal Component Analysis was applied to reduce dimensionality to as few principal components as possible explaining still most of the variance in the data. Additionally, meteorological data and catchment properties derived from hydrogeologic, soil and land use maps were included to better understand the results and to check hypotheses about underlying processes and driving forces. The first six components exhibited an eigenvalue exceeding one and explained 73% of the total variance. Analysis of the loadings and comparison with meteorological and catchment properties allowed assigning runoff generating processes to the principal components. The first principal component represented the mean runoff behavior of the time series from all catchments. Further components could be related to precipitation patterns that exhibited a northwest-southeast and southwest-northeast gradient, a higher evapotranspiration by wetlands and river lakes, water management activities and specific behavior or measurement errors at single gauges. Despite our hypothesis that soil, groundwater and land use properties are crucial to understand discharge patterns at small catchments the results show that precipitation patterns and the area of river lakes and wetlands explain most of the variance in our data set. Our method was suited to extract common patterns in catchment runoff. We show challenges in defining catchment similarity arising from runoff generating processes which are correlated. Additionally, similarity in water management and other anthropogenic influences had to be included in this research area. Further, we used this classification to estimate catchments' vulnerability to extremes, especially low flows, and formulate key concerns for water managers.

Thomas, B. D.; Lischeid, G.; Steidl, J.; Dannowski, R.

2012-04-01

195

Using stable isotopes to estimate and compare mean residence times in contrasting geologic catchments (Attert River, NW Luxembourg)  

NASA Astrophysics Data System (ADS)

In recent years, stable isotopes have been increasingly used to characterize important aspects of catchment hydrological functioning, such as water storage dynamics, flow pathways and water sources. These characteristics are often synthesized by the Mean Residence Time (MRT), which is a simple catchment descriptor that employ the relation of distinct stable isotopic signatures in the rainfall input and streamflow output of a catchment that are significantly dampened through sub-surface propagation. In this preliminary study, MRT was estimated in the Attert River catchment (NW Luxembourg), where previous studies have shown that lithology exerts a major control on runoff generation. The Attert catchment lies at the transition zone of contrasting bedrock lithology: the Northern part is characterized by Devonian schist of the Ardennes massif, while sedimentary deposits of sandstone and marls dominate in the south of the catchment. As a consequence of differing lithologic characteristics, hydrological processes change across scales. The schistose catchments exhibit a delayed shallow groundwater component, sandstone catchments have slow-responding year-round groundwater component, whereas flashy runoff regimes prevails in the marly catchments. Under these circumstances, the MRTs are expected to vary significantly according to lithology, and provide additional understanding in internal catchment processes and their scale dependencies. In order to test this, bi-weekly monitoring of rainfall and discharge stable water isotope composition (oxygen-18 and deuterium) has been carried out since 2007 in 10 nested sub-catchments ranging in size from 0.4 to 247 km2 in the Attert catchment. MRT was estimated using different lumped convolution integral models and sine wave functions with varying transit times distributions (TTDs). TTDs were evaluated through calibration. Further research efforts will deal with the application of conceptual models to simulate and compare TTD, using additional data and process understanding for model evaluation in the studied catchments.

Martínez-Carreras, N.; Fenicia, F.; Frentress, J.; Wrede, S.; Pfister, L.

2012-04-01

196

Patterns of Nitrate Export From two Hydrolgically Similar Catchments  

NASA Astrophysics Data System (ADS)

Recently there has been considerable interest in exploring how hydrologic flowpaths influence the export of solutes such as NO3- during hydrological events. The knowledge of flowpaths derived from TOPMODEL in combination with the potential solute source areas within the soil profile can be used to characterize the export of solutes. We explored the use of the topographic index (ln[a/tan B], where a is the upslope contributing area and B is the local slope) and field based measurements of soil water and groundwater to characterize surface water chemistry for two subcatchments of the Archer Creek catchment located in the Adirondack Mountains of NY. The two subcatchments are located in the headwaters of the catchment and have similar topography with steep slopes and incised streams, but marked differences in the magnitude of stream NO3- concentrations. We hypothesized that the temporal patterns in surface water concentrations of NO3- in stream water during hydrologic events will be similar between these two subcatchments and the relative contributions of deep verses shallow flow will be similar between the two catchments under a wide range of hydrologic regimes. Combining TOPMODEL predictions of flow contributions with predictions of concentrations of solutes in different hydrologic reservoirs over hydrological events was used to model the evolution of solutes in these subcatchments. Preliminary results have suggested that temporal patterns in stream water chemistry are similar between the catchments. Thus differences in the magnitude of stream NO3- concentrations can be attributed to the relative amounts of NO3- generated in the surface soil of each subcatchment. The catchment with higher NO3- has an overstory vegetation that is associated with high rates of N mineralization and nitrification in the Adirondack region. Despite these differences in the magnitude of NO3- concentrations, the hydrological responses of each subcatchment are similar suggesting that there are no substantial differences in flowpaths between the two catchments.

Christopher, S. F.; Mitchell, M. J.; Inamdar, S.; Page, B. D.

2002-12-01

197

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

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.

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

2006-03-17

198

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

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.

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

2006-01-01

199

Hydrologic sensitivity of headwater catchments to climate and landscape variability  

NASA Astrophysics Data System (ADS)

Headwater streams cumulatively represent an extensive portion of the United States stream network, yet remain largely unmonitored and unmapped. As such, we have limited understanding of how these systems will respond to change, knowledge that is important for preserving these unique ecosystems, the services they provide, and the biodiversity they support. We compare responses across five adjacent headwater catchments located in Tenderfoot Creek Experimental Forest in Montana, USA, to understand how local differences may affect the sensitivity of headwaters to change. We utilize global, variance-based sensitivity analysis to understand which aspects of the physical system (e.g., vegetation, topography, geology) control the variability in hydrologic behavior across these basins, and how this varies as a function of time (and therefore climate). Basin fluxes and storages, including evapotranspiration, snow water equivalent and melt, soil moisture and streamflow, are simulated using the Distributed Hydrology-Vegetation-Soil Model (DHSVM). Sensitivity analysis is applied to quantify the importance of different physical parameters to the spatial and temporal variability of different water balance components, allowing us to map similarities and differences in these controls through space and time. Our results show how catchment influences on fluxes vary across seasons (thus providing insight into transferability of knowledge in time), and how they vary across catchments with different physical characteristics (providing insight into transferability in space).

Kelleher, Christa; Wagener, Thorsten; McGlynn, Brian; Nippgen, Fabian; Jencso, Kelsey

2013-04-01

200

Keeping it simple: a conceptual model of DOC dynamics in a subarctic alpine catchment  

NASA Astrophysics Data System (ADS)

Understanding hydrological processes in subarctic alpine catchments characterised with discontinuous permafrost is important in order to understand carbon exports. Subarctic catchments have large storages of carbon in organic and permafrost soils. Active layer depth is one of the largest controlling factors of the release of dissolved organic carbon (DOC) due to its control on runoff pathways. Therefore, any change of this depth will affect the amount of DOC mobilised from these catchments. Simple low parameterised conceptual models offer the ability to characterise hydrological processes and linked DOC dynamics without introducing many of the uncertainties linked to high parameterised models. Lumped models can also be used to identify sources of DOC within catchments. Here, we investigate hydrological sources, flow pathways and consequently DOC dynamics in the Granger Basin, Canada, a subarctic alpine catchment using data collected from 2001 to 2008. The catchment is distinguished by aspect dependant discontinuous permafrost and seasonal frost, compounded further by differences in soil and vegetation types. Applying a simple low parameterised conceptual model allowed identification of the dominant flow paths of the main hydrological response units. The results showed that it was necessary to include active layer dynamics combined with aspect to represent the hydrological and DOC dynamics. The model provides information on the effect of climatic conditions on DOC releases. By identifying the key flow paths and relating these to spring freshet DOC exports over multiple years it is possible to gain an insight of the how climatic changes might affect hydrological processes within subarctic catchments.

Lessels, J. S.; Tetzlaff, D.; Carey, S. K.; Soulsby, C.

2013-12-01

201

Source and transport factors influencing storm phosphorus losses in agricultural catchments  

NASA Astrophysics Data System (ADS)

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 differentiated by dynamic or static transport metrics alone, regardless of differences in soil P. Where hydrological dynamics were similar, non-static transport metrics and P source information additional to soil P, may be required to differentiate the relative risk of storm TRP in these agricultural catchments. Regardless of differences in hydrological dynamics, information on land use and management, such as time of ploughing, may be required to differentiate the relative risk of PP loss in these agricultural catchments.

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

2014-05-01

202

Exploring the link between spatial hydrologic variability and catchment similarity for the purpose of regionalisation  

NASA Astrophysics Data System (ADS)

Catchments are complex systems, with a large number of strongly interdependent variables operating at many space and time scales. This makes it difficult to discover the processes in a particular catchment in greater detail as a prerequisite for runoff modelling. Instead of studying a particular catchment in much detail, we can explore spatial patterns of the runoff response to learn about the most important runoff generating processes in a study area. This can be done by linking the spatial variability of runoff signatures with that of climate and catchment characteristics through statistical techniques. The gained additional knowledge about catchment functioning can then be the departure for improved regionalisation models, which enable more reliable estimates at ungauged basins than models which do not take process information into account. This contribution explores the link between representations of hydrological variability and catchment similarity measures for the purpose of regionalisation. Guided by case studies of an Austrian and a German study area, we show how spatial patterns of the various runoff signatures, from droughts to floods, together with representations of climate and catchment characteristics can be jointly used to infer catchment functioning in terms of most important runoff generating processes. It is further shown how the information about similarly and differently functioning catchments can be employed to improve statistical regionalisation models. Results indicate that for seasonal climates, low flow processes are strongly linked with seasonality patterns. Grouping catchments according to seasonality can therefore significantly improve the predictive performance of regionalisation. The German study showed that shape and magnitude of the annual flood distributions are linked (i) to different catchment/climate characteristics (ii) in different (linear/non-linear) ways. This suggested a combined model of Top-kriging (linear model for flood magnitude) with the Index Flood method (non-linear model for flood shape) as suitable regionalisation method. A cross-validation analysis showed that the combined model performed indeed better than alternative statistical models which did not take process information into account. We conclude that the spatial patterns of runoff signatures, together with those of climate and catchment characteristics, contain a wealth of information, which can be profitably used for runoff predictions in ungauged basins.

Laaha, Gregor; Salinas, Jose L.; Blöschl, Günter

2013-04-01

203

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

NASA Astrophysics Data System (ADS)

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 determine differently acting mass movement processes. A process-based approach is applied to assess the importance of hillslope sediment production, storage and transport throughout the catchments, including orthophoto-interpretation, hillslope profile surveying, photo monitoring, geomorphological mapping, GIS and DEM computing as well as a combination of different field techniques for bed load monitoring. Appropriate hillslope test sites within the headwater catchments are selected in order to fulfill the main aims of this study as well as to monitor contemporary rates of hillslope fluxes. The designed monitoring instrumentation of the slope test sites includes nets, stone tracer lines, wooden sticks, peg lines, slop wash traps and remote site monitoring cameras. Hillslope profile surveying, geomorphological mapping and measurements of solute yields from the slope systems are carried out at each test site. Channel longitudinal- and cross profiles are measured in defined test stretches of the first order streams, located downhill of the slope test sites. Within the same channel test stretches extensive pebble counts (grain size, grain shape) are conducted seasonally and tracer lines are installed in order to trace different bed load components. The four selected headwater areas are characterized by different intensities of hillslope-channel coupling, mainly due to the distinct valley morphometries affected by the glacial inheritance of the Nordfjord region. Where hillslope-channel coupling exists, primary coarse material is delivered from the hillslopes into the channels via snow avalanches. These coarse grained and angular components can be traced within the channel test stretches. Research on the complex evolution of hillslope-channel (de-) coupling over time and contemporary sediment transfer fluxes contributes to a better understanding of possible trends of mountain landscape development.

Laute, Katja; Beylich, Achim A.

2010-05-01

204

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

NASA Astrophysics Data System (ADS)

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.

Rademacher, Laura K.; Clark, Jordan F.; Clow, David W.; Hudson, G. Bryant

2005-02-01

205

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

USGS Publications Warehouse

[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.

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

2005-01-01

206

Estimation of natural pollution loads from streamflow measurements in remote catchments  

Microsoft Academic Search

In a study conducted in Marmot Creek Basin (total area 9.40 kmz) situated in the Rocky Mountains of Alberta, equations were developed to obtain gross estimates of the total inorganic solutes dislodged from three forest catchments on a monthly and annual basis. The r2 range of the equations was 99% or greater, indicating excellent fit in all cases. The equations

Teja Singh; Y. P. Kalra

1977-01-01

207

Future climate scenarios and rainfall–runoff modelling in the Upper Gallego catchment (Spain)  

Microsoft Academic Search

Global climate change may have large impacts on water supplies, drought or flood frequencies and magnitudes in local and regional hydrologic systems. Water authorities therefore rely on computer models for quantitative impact prediction. In this study we present kernel-based learning machine river flow models for the Upper Gallego catchment of the Ebro basin. Different learning machines were calibrated using daily

C. M. Bürger; O. Kolditz; H. J. Fowler; S. Blenkinsop

2007-01-01

208

The sediment budget of a highly dynamic mesoscale catchment: The River Isábena  

NASA Astrophysics Data System (ADS)

The paper presents the sediment budget of the Isábena basin, a highly dynamic 445-km 2 catchment located in the Central Pyrenees that is patched by highly erodible areas (i.e., badlands). The budget for the period 2007-2009 is constructed following a methodology that allows the interpolation of intermittent measurements of suspended sediment concentrations and enables a subsequent calculation of sediment loads. Data allow specification of the contribution of each subbasin to the water and sediment yield in the catchment outlet. Mean annual sediment load was 235,000 t y - 1 . Specific sediment yield reached 2000 t km - 2 y - 1 , a value that indicates very high sedimentary activity, especially in the case of Villacarli and Lascuarre subcatchments, were most badlands are located. The specific sediment yield obtained for the entire Isábena is 527 t km - 2 y - 1 , a high value for such a mesoscale basin. Results show that a small part of the area (i.e., 1%) controls most of the catchment's gross sediment contribution. Sediment delivery ratio (ratio between sediment input from primary sources and basin export) has been estimated at around 90%, while in-channel storage represents the 5% of the annual load on average. The high connectivity between sediment sources (i.e., badlands) and transfer paths (i.e., streamcourses) exacerbates the influence of the local sediment production on the catchment's sediment yield, a quite unusual fact for a basin of this scale.

López-Tarazón, J. A.; Batalla, R. J.; Vericat, D.; Francke, T.

2012-02-01

209

Development of a forestry plan for the upper catchment of the South Esk to provide options for socio-economic benefits and taking account of stakeholder participation   

E-print Network

stakeholder participation in the implementation of the South Esk Catchment Management Plan since 2010 and their possible future working relationship to implement planting activities, as proposed in the preliminary forestry plan. The research was carried out...

Lew, Siew Yan

210

Catchment-scale biogeography of riverine bacterioplankton  

PubMed Central

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

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

2015-01-01

211

Catchment-scale biogeography of riverine bacterioplankton.  

PubMed

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

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

2015-02-01

212

Preliminary Pliocene-Pleistocene Stable-Isotope and Paleosol Data From the Fish Creek- Vallecito Basin, Southern California: Insights Into Paleoclimate From Pedogenic Carbonate  

NASA Astrophysics Data System (ADS)

In this study we use detailed measurements and isotopic analyses of paleosols in the Fish Creek-Vallecito basin (FCVB), southern California, to interpret changes in Pliocene-Pleistocene paleoclimate in the area. The FCVB currently lies in a hyperarid rain shadow (MAP = 15-17 cm) formed by the Peninsular Ranges. The timing of Peninsular Range uplift is not known, although recent work suggests it could have occurred as recently as early Pleistocene (Mueller et al., 2006). In the FCVB, abundant paleosols are exposed in a thick, tilted stratigraphic section that accumulated in the hanging wall of the West Salton detachment fault. New high-resolution magnetostratigraphic dating allows us to determine the age of paleosol horizons to within an average of ? 0.06 m.y.. Pedogenic carbonate nodules from 23 horizons ranging in age from 3.7 to 1.0 Ma, spanning a thickness of 2.5 km, were analyzed for oxygen and carbon isotopic compositions on a Gasbench and MAT 253 mass spectrometer. The data reveal an increase in carbonate ?18O values at about 2.5-3.0 Ma, from -10.5 ? 0.1 ‰ to -9.2 ‰ ? 0.2 ‰ (VPDB). Pedogenic carbonate ?13C values vary between -10.4 ‰ and -3.8 ‰ (VPDB) with no apparent trend. A total of forty-nine paleosols were described in the study interval. Most paleosols have shallow carbonate (Bk) horizons and thin, poorly-developed A horizons. Our finding of an increase in ?18O corresponds broadly to a previous study of fossil horse teeth (Brogenski, 2001), which recorded a 2 ‰ increase in ?18O in meteoric water at about 2 Ma. Preliminary recalculation of Brogenski's fossil site ages suggests that the change in ?18O occurred earlier than previously reported, around 2.4 Ma. The increase in ?18O at 2.5-3.0 Ma coincides with a global climate change caused by the onset of northern hemisphere glaciation, and may reflect (1) an increase in enriched Pacific Ocean-derived storms and decrease in the concentration of isotopically depleted monsoonal sources, (2) a change in the source of atmospheric water vapor within the Pacific Ocean, or (3) an increase in soil water evaporation driven by an increase in local temperature or of summer precipitation. The observed increase in ?18O is opposite of the change that would be produced by the onset of a rain shadow in the FCVB. This suggests that uplift of the Peninsular Ranges occurred before 3.7 Ma or after 1 Ma, or perhaps took place in two stages before 3.7 Ma and after 1 Ma. We interpret the majority of paleosols as Aridisols that formed under arid to semi-arid conditions. Measurements of depth to the soil carbonate (Bk) horizon show an average decompacted depth to Bk of 19.7 ? 1 cm, which corresponds to a mean annual precipitation of approximately 25 cm (Retallack, 2005). This is similar to modern annual rainfall in coastal San Diego and is 8-10 cm more than in the present-day FCVB. While there is considerable scatter in depth-to-Bk measurements, clear trends are not apparent, suggesting that aridity was the dominant climate condition in the basin between 3.7 and 1.0 Ma. Other indicators of climate change in the area, including rise and fall of lake levels and inferences from faunal assemblages, may reflect external factors (i.e. fluvial inflow) rather than local climate conditions.

Peryam, T. C.; Dorsey, R. J.; Bindeman, I.; Housen, B.; Palandri, J.

2008-12-01

213

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

USGS Publications Warehouse

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 valley confinement. * Natural and human-caused disturbances such as mass movements, logging, fire, channel modifications for navigation and flood control, and gravel mining also have varying effects on channel condition, bed-material transport, and distribution and area of bars throughout the study areas and over time. * Existing datasets include at least 16 and 18 sets of aerial and orthophotographs that were taken of the study areas in the Tillamook Bay tributary basins and Nehalem River basin, respectively, from 1939 to 2011. These photographs are available for future assessments of long-term changes in channel condition, bar area, and vegetation establishment patterns. High resolution Light Detection And Ranging (LiDAR) surveys acquired in 2007-2009 could support future quantitative analyses of channel morphology and bed-material transport in all study areas. * A review of deposited and mined gravel volumes reported for instream gravel mining sites shows that bed-material deposition tends to rebuild mined bar surfaces in most years. Mean annual deposition volumes on individual bars exceeded 3,000 cubic meters (m3) on Donaldson Bar on the Wilson River, Dill Bar on the Kilchis River, and Plant and Winslow Bars on the Nehalem River. Cumulative reported volumes of bed-material deposition were greatest at Donaldson and Dill Bars, totaling over 25,000 m3 per site from 2004 to 2011. Within this period, reported cumulative mined volumes were greatest for the Donaldson, Plant, and Winslow Bars, ranging from 24,470 to 33,940 m3. * Analysis of historical stage-streamflow data collected by the U.S. Geological Survey on the Wilson River near Tillamook (14301500) and Nehalem River near Foss (14301000) shows that these rivers have episodically aggraded and incised, mostly following high flow events, but they do not exhibit systematic, long-term trends in bed elevation. * Multiple cross sections show that channels near bridge crossings in all six study areas are dynamic with many subject to incision and aggradation as well as lateral shifts in thalweg position and bank deposit

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

2012-01-01

214

Scenario analysis of nutrient management at the river basin scale  

Microsoft Academic Search

A new river basin model (TRANS) for studying the transport, removal and accumulation of nutrients in rivers, lakes and riparian areas has been developed and tested on data from a 115 km2 river basin in Denmark (river Gjern). The model combines catchment information on soil type and land use with a physical hydrodynamic modelling system and several semi-dynamic empirical models

B. Kronvang; L. M. Svendsen; J. P. Jensen; J. Dørge

1999-01-01

215

Modeling coupled surface water - Groundwater processes in a small mountainous headwater catchment  

NASA Astrophysics Data System (ADS)

Hydrological models for headwater catchments have typically excluded deep groundwater flow based on the assumption that it is a negligible component of the water budget. This study tests this assumption using a coupled surface water-groundwater model to explore the potential contribution of deep groundwater recharge to the bedrock in a snowmelt-dominated headwater catchment (Upper Penticton Creek 241) in the Okanagan Basin, British Columbia. Recharge to the bedrock is estimated at ?27% of the annual precipitation over the period 2005-2010, recognizing the uncertainty in this estimate due to data limitations, parameter uncertainty and calibration errors. A specified outward flux from the catchment boundary within the saturated zone, representing ?2% of the annual water budget, was also included in the model. This outward flux contributes to cross-catchment flow and, ultimately, to groundwater inflow to lower elevation catchments in the mountain block. This modeling exercise is one of the first in catchment hydrologic modeling within steep mountainous terrain in which the bedrock is not treated as impermeable, and in which recharge to the bedrock and discharge to the surrounding mountain block were estimated.

Voeckler, Hendrik M.; Allen, Diana M.; Alila, Younes

2014-09-01

216

Assessment of interbasin groundwater flows between catchments using a semi-distributed water balance model  

NASA Astrophysics Data System (ADS)

In hydrological modeling it is often assumed that the aquifers boundaries are formed by the geographical demarcation of the catchment. However, this assumption is rarely met, given the existence of groundwater flows going beyond the catchment limits. The assessment of interbasin groundwater flows is crucial when managing water resources in areas where baseflows are mainly formed by groundwater, especially when catchments are managed separately. Aiming at estimating the volume and direction of the main groundwater flows, this work presents a new methodological approach for hydrological modeling. This approach employs a semi-distributed water balance model created with lumped models. This model is formulated in such a way that a part of the groundwater discharge of a specific catchment can become baseflows in other catchments, which helps characterize interbasin groundwater flows. This methodology is applied in the headwater of the Segura River Basin (southeast of Spain), where groundwater plays an important role in surface hydrology. The catchments are modeled with a high goodness of fit, and the main interbasin groundwater flows between them is evaluated, proving its importance in the characterization of hydrological modeling.

Pellicer-Martínez, Francisco; Martínez-Paz, José Miguel

2014-11-01

217

A Basin Morphology Approach to Colour Image Segmentation by Region Merging  

E-print Network

A Basin Morphology Approach to Colour Image Segmentation by Region Merging Erchan Aptoula and S by region merging, with the procedure being formalized as a basin morphology, where regions are "eroded" in order to form greater catchment basins. The result is a fully automated processing chain, with multiple

Lefèvre, Sébastien

218

Farmer Tree Nursery as a Catalyst for Developing Sustainable Best Management Land Use Practices in Lake Victoria Catchments Ecosystem  

NASA Astrophysics Data System (ADS)

Support to farmer nurseries is classified as either hard referring to material inputs (tree seed, water, tools and fencing) or soft (information, training and backstopping advice). Against a background of poor services for smallholder farmers in the Lake Victoria basin, it was hypothesized that a number of support agents operating at the grassroot level together with farmers themselves provide the different support functions needed in the establishment of farmer tree nurseries. Through financial support from Inter-University Council of East Africa coordinated VicReS Project, a collaborative project involving Kenyatta University (Kenya), Kenya Agricultural Research Institute (KARI) and Mulingano Agricultural Research Institute (Tanzania) has been able to initiate reforestation/afforestation activities in Lake Victoria catchments ecosystems of western Kenya and western Tanzania. Through the initial activities, a total of twenty four farmer groups have been identified in western Kenya and supported through capacity building and supply of basic inputs for tree nursery seed bed preparation and management. The groups have been able to set up tree nurseries and are now managing seed beds with a total of 450,000 agro-forestry seedlings, mainly Grevillea robusta and Casuarina spp. The farmers intend to distribute the seedling among the members for planting on farm boundaries, around homesteads and woodlots within their homesteads and sell the surplus. Preliminary findings show that there is an urgent need to facilitate grassroot level support systems with larger participation from the national extension service for provision of training and backstopping advice. Strengthening the human capital of farmers and service providers emerges as critical in increasing impact. Farmer nurseries are shown to play a number of important and interrelated functions in building natural, human and social capital. Monitoring and evaluating farmer nurseries in catalyzing these three functions should therefore receive proper attention in assessing impact of sustainable land use systems. Policies need to be well articulated to address some of the major constrains identified in the Lake Victoria catchments ecosystem.

Shisanya, C. A.; Makokha, M. O.; Kimani, S. K.; Kalumuna, M.; Tenge, A.

219

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

220

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

NASA Astrophysics Data System (ADS)

Budyko (1974) postulated that long-term catchment water balance is controlled to first order by the available water and energy. This leads to the interesting question of how do landscape characteristics (soils, geology, vegetation) and climate properties (precipitation, potential evaporation, number of wet and dry days) interact at the catchment scale to produce such a simple and predictable outcome of hydrological partitioning? 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 paramterizations) are subjected to the 12 different climate forcings, resulting in 144 10-year 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=?(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 subsurface storage release explains the observed trend. This time scale combines several geomorphologic and hydraulic soil properties. Catchments with relatively longer subsurface 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 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.

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

2013-12-01

221

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

222

Catchment classification based on characterisation of streamflow and precipitation time-series  

NASA Astrophysics Data System (ADS)

The formulation of objective procedures for the delineation of homogeneous groups of catchments is a fundamental issue in both operational and research hydrology. For assessing catchment similarity, a variety of hydrological information may be considered; in this paper, gauged sites are characterised by a set of streamflow signatures that include a representation, albeit simplified, of the properties of fine time-scale flow series and in particular of the dynamic components of the data, in order to keep into account the sequential order and the stochastic nature of the streamflow process. The streamflow signatures are provided in input to a clustering algorithm based on unsupervised SOM neural networks, providing an overall reasonable grouping of catchments on the basis of their hydrological response. In order to assign ungauged sites to such groups, the catchments are represented through a parsimonious set of morphometric and pluviometric variables, including also indexes that attempt to synthesize the variability and correlation properties of the precipitation time-series, thus providing information on the type of weather forcing that is specific to each basin. Following a principal components analysis, needed for synthesizing and better understanding the morpho-pluviometric catchment properties, a discriminant analysis finally classifies the ungauged catchments, through a leave-one-out cross-validation, to one of the above identified hydrologic response classes. The approach delivers quite satisfactory results for ungauged catchments, since the comparison of the two cluster sets shows an acceptable overlap. Overall results indicate that the inclusion of information on the properties of the fine time-scale streamflow and rainfall time-series may be a promising way for better representing the hydrologic and climatic character of the study catchments.

Toth, E.

2012-09-01

223

On the Relationship Between Soil Depth and Mean Water Transit Time in Zero-order Catchments  

NASA Astrophysics Data System (ADS)

In order to enhance prediction of the hydrologic response of ungaged basins, it is necessary to relate water transit times to easily measurable catchment properties. Groundwater transit times have been modeled for 10 sub-catchments of two small catchments in the Santa Catalina Mountains north of Tucson, Arizona (USA). The two zero-order catchments are north facing with very similar drainage area, mean slope, and climate. The main difference between the two sites is bedrock geology: one is underlain by Schist and the other by Granite. The modeled water transit time distributions were obtained from hydrometric and isotopic data analysis, and were compared to a number of topographic properties such as mean slope, area, mean flow path length, curvature. None of those could explain much of the variation of the transit times. In a second step, available modeled soil depth distributions were used to relate average soil depth to mean transit time. The modeled soil depth data (Pelletier and Rasmussen, 2009) was generated using only basic climate data (mean annual precipitation and mean annual temperature), high resolution digital elevation model (LIDAR) data and geologic data (parent material). These modeled soil depths were averaged over the sub-catchments. It was found that they are able to explain 80 percent of the variation of the groundwater transit times. This means that in these catchments mean soil depth is the predominant transit time control. With this knowledge it is possible to predict transit times (and therefore catchment response) by modeling soil depths, even in catchments where there is sparse hydrologic information available.

Heidbuechel, I.; Troch, P. A.; Pelletier, J. D.; Rasmussen, C.; Lyon, S. W.

2009-12-01

224

INCORPORATING THE SPATIO-TEMPORAL DISTRIBUTION OF RAINFALL AND BASIN GEOMORPHOLOGY INTO NONLINEAR  

E-print Network

1 INCORPORATING THE SPATIO-TEMPORAL DISTRIBUTION OF RAINFALL AND BASIN GEOMORPHOLOGY INTO NONLINEAR streamflow series, spatio-temporal structure of precipitation and catchment geomorphology into a nonlinear of incorporating process-specific information (in terms of catchment geomorphology and an a-priori chosen

Foufoula-Georgiou, Efi

225

Hydrological response of a Mediterranean agricultural catchment on a Vertic soil  

NASA Astrophysics Data System (ADS)

Hydrological response of vertic soils is strongly controlled by the modification of its hydraulic conditions by the shrinking and swelling cycles, which are controlled by the climatology of the year. This presents additional challenges to the already difficult task of hydrologic and erosion modelling at hillslope and catchment scale (Allen et al., 2005). However, there is limited experimental information on the hydrologic response of vertic soils at catchment scale. This communications presents a preliminary evaluation of the hydrologic impact of an small, 8 ha, catchment in Southern Spain covered by olive groves on a vertic soil. This evaluation is made on the runoff and rainfall records measured at catchment scale from September 2006 to August 2011, and at runoff plot scale from September 2000 to August 2004 and September 2009 to August 2011. These results are analyzed following the same statistical analysis described by Taguas et al. (2009) enlarging this analysis with an evaluation of the correlation between the hydrologic response of the catchment, with the evolution of the soil water content in the orchard simulated using a conceptual soil water balance model, WABOL (Abazi et al., 2012) The results of the analysis will be discussed in relation to the variability of the hydrologic response at different time and spatial scales (catchment and hillslope) and its implications for modelling and extrapolation to similar soils under different climate and crop conditions.

Gomez, J. A.; Taguas, E.; Licciardello, F.

2012-04-01

226

What causes similarity in catchments?  

NASA Astrophysics Data System (ADS)

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.

Savenije, Hubert

2014-05-01

227

K Basins hazard analysis  

SciTech Connect

The 105-K East (KE) and 105-K West (KW) Basins in the 100 K Area of the Hanford Site have been used for storage of irradiated N Reactor and single-pass reactor fuel. Remaining spent fuel is continuing to be stored underwater in racks and canisters in the basins while fuel retrieval activities proceed to remove the fuel from the basins. The Spent Nuclear Fuel (SNF) Project is adding equipment to the facility in preparation for removing the fuel and sludge from the basins. In preparing this hazard analysis, a variety of hazard analysis techniques were used by the K Basins hazard analysis teams, including hazard and operability studies, preliminary hazard analyses, and ''what if'' analyses. This document summarizes the hazard analyses performed as part of the safety evaluations for the various modification projects and combines them with the original hazard analyses to create a living hazard analysis document.

MCCALL, T.B.

2002-10-09

228

K Basin Hazard Analysis  

SciTech Connect

The 105-K East (KE) and 105-K West (KW) Basins in the 100 K Area of the Hanford Site have been used for storage of irradiated N Reactor and single-pass reactor fuel. Remaining spent fuel is continuing to be stored underwater in racks and canisters in the basins while fuel retrieval activities proceed to remove the fuel from the basins. The Spent Nuclear Fuel (SNF) Project is adding equipment to the facility in preparation for removing the fuel and sludge from the basins. In preparing this hazard analysis, a variety of hazard analysis techniques were used by the K Basins hazard analysis teams, including hazard and operability studies, preliminary hazard analyses, and ''what if'' analyses. This document summarizes the hazard analyses performed as part of the safety evaluations for the various modification projects and combines them with the original hazard analyses to create a living hazard analysis document.

MCCALL, T.B.

2002-03-21

229

Preliminary results on the characterization of Cretaceous and lower Tertiary low-permeability (tight) gas-bearing rocks in the Wind River Basin, Wyoming  

SciTech Connect

The Wind River Basin is a structural and sedimentary basin in central Wyoming (Figure 1) that was created during the Laramide orogeny from Late Cretaceous through Eocene time. The objectives of the Wind River Basin tight gas sandstone project are to define the limits of the tight gas accumulation in the basin and to estimate in-place and recoverable gas resources. The approximate limits of the tight gas accumulation are defined from available drillhole information. Geologic parameters, which controlled the development of the accumulation, are studied in order to better understand the origins of tight gas accumulations, and to predict the limits of the accumulation in areas where little drillhole information is available. The architecture of sandstone reservoirs are studied in outcrop to predict production characteristics of similar reservoirs within the tight gas accumulation. Core and cuttings are used to determine thermal maturities, quality of source rocks, and diagenetic histories. Our work thus far has concentrated in the Wind River Indian Reservation in the western part of the basin.

Fouch, T.D.; Keefer, W.R.; Finn, T.M. [and others

1993-12-31

230

Sediment connectivity evolution on an alpine catchment undergoing glacier retreat  

NASA Astrophysics Data System (ADS)

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

Goldin, Beatrice; Rudaz, Benjamin; Bardou, Eric

2014-05-01

231

Factors controlling mercury transport in an upland forested catchment  

USGS Publications Warehouse

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.

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

1998-01-01

232

Bayesian Uncertainty of Thwaites Glacier Catchment Radar Stratigraphy  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

233

Fate of organic contaminants in a boreal forest catchment  

NASA Astrophysics Data System (ADS)

The aim of the study was to investigate and predict the impact of hydrological and atmospheric processes on the mobilisation of contaminants in a remote catchment where the major input is related to diffuse pollution. The project included priory substances according to the European water framework directive (WFD), such as the persistent organic pollutants (POPs) HCB, PCBs and dioxins. The study was conducted at a well-characterised catchment system in northern Sweden dominated by two landscape types: forest and mire. Chemical analyses of POPs in forest soil and mire peat at various depths were performed. Evaluation of POP composition by principal component analysis (PCA) showed distinct differences between surface and deeper samples. This was attributed to vertical transport, degradation and/or shifting sources over time. The calculated net vertical transport differed between surface (0.3% of the pollutant reservoir) and deeper soils (8.0 %), suggesting that vertical transport conditions and processes differ in the deeper layers compared to the surface layers.The fate of POPs in soils and waters was explored through the development of a chemical fate model. The northerly location of the studied catchment enabled a study on the impact of spring snow melt and associated hydrological processes on contaminant mobilization. Input was based on bulk atmospheric deposition and was dominated by accumulation in the winter snowpack. The model considered air-soil exchange and accumulation in forest and mire soil as well as export of dissolved and particle-bound POPs from soil to catchment surface water. The predicted export of POPs to catchment surface waters was up to 40 times higher the during snow melt period (three week during April/May) compared to the snow covered period (approximately 4 months), highlighting the importance of the seasonal snow pack as a source of these chemicals. Release from soils was governed by the POP concentration in soil, the fraction of soil organic carbon and soil-water dissolved organic carbon (DOC) content. Significant differences in export of POPs were apparent between the forested and mire areas, and this could be linked to observed differences in hydrology, biogeochemistry and flux of DOC. Levels of POPs in surface water along the water path from the studied catchment to the Baltic Sea (the Gulf of Bothnia subbasin) were measured and the results showed that for this water system, atmospherically derived diffuse pollution has impact on the surface water quality in addition to downstream point sources. In conclusion, it is evident that a full understanding of the baseline contribution and the soil-to-water processes controlling the transport of priority substances at catchment scale is a prerequisite for assessing the variation of priority substances in water streams and river basins on a seasonal and regional scale. It is also clear that mobilization of headwater atmospherically derived diffuse pollution may have an impact on stream water quality in addition to downstream point sources. The above findings are applicable to a wide variety of north European catchments systems and provide an integrated and process-based understanding of base-line contamination of major catchments. The presented data highlight the findings from the PERSPEC project, which was possible under the umbrella of the European Commission's 6th Framework Programme project SNOWMAN (contract no ERAC-CT-2003-003219).

Bergknut, Magnus; Meijer, Sandra; Halsall, Crispin; Ågren, Anneli; Laudon, Hjalmar; Köhler, Stephan; Jones, Kevin; Tysklind, Mats; Wiberg, Karin

2010-05-01

234

Preliminary Study on Spatial Recognition of Key Area of Flood Discharge in Mountainous City: A Case in Panxi River Basin in Chongqing City  

Microsoft Academic Search

In this paper, the sinks, the steep slope areas, and locally flat areas, and junction sites of reach are extracted using spatial analysis in Geographical Information System (GIS) and hydrology analysis, based on study area Panxi river basin in Chongqing main city. The junction sites of reaches are directly determined as key sites of flood discharges. Overlaying other factors, three

Han Guifeng; Yan Wentao; Chenshu Yilang; He Qiang

2010-01-01

235

D/H variation in terrestrial lipids from Santa Barbara Basin over the past 1400 years: A preliminary assessment of paleoclimatic relevance  

E-print Network

D/H variation in terrestrial lipids from Santa Barbara Basin over the past 1400 years analyzed D/H ratios of common terrestrial leaf wax lipids in a 1400 year sediment core from the Santa; Glassow, 2002) and flood deposit thickness (e.g. Schimmelmann et al., 2003). One new proxy that holds

Sessions, Alex L.

236

Evaluation of erosion in equipped basins: preliminary results of a comparison between the Gavrilovic model and direct measurements of sediment transport  

NASA Astrophysics Data System (ADS)

The study of the hydrologic characters of a water course permits the correct management of the corresponding basin and a greater control over the water resources of the whole basin; therefore, a suitable planning and maintenance of the necessary interventions along the water course, especially in proximity of the outlet to sea, becomes necessary. An evaluation of the solid transport allows an estimation of the erosion to which the basin is subjected as a result of the river flow, and further helps to prevent hydrologic disasters in the possible risk zones. Among the various experimental techniques in use for measuring the suspended-solid transport, nuclear methods have been preferably used in this research, which are based on monitoring the concentration of the suspended sediments. The suspended-solid concentration is detected by the attenuation of radioactivity emitted by a source of 241Am dipped in the water. This attenuation, due to the presence of the sediments transported in great amounts during events of flood is measured using a scintillation detector made up of a crystal of NaI(Tl). With appropriate calibration curves built both in the laboratory and in the field, it is possible to trace the amount of suspended-solid transport in a certain river section that is located in the proximity of the river outlet. This methodology, applied to different equipped basins in Italy and Africa, is particularly useful for small and medium water courses (similar to those of the Apennine ranges in Italy), allowing an assessment of the erosion in the whole watershed. In this note, the techniques used are introduced in detail, with particular attention to the instrument calibration, and the numerical results obtained for some basins in the Marche region (Italy) are compared with some empirical formulae used in previous reports for the calculation of erosion.

Tazioli, A.

2009-01-01

237

Dissolved Organic Carbon dynamics in a Mediterranean mountain catchment  

NASA Astrophysics Data System (ADS)

The dynamics of water solutes in Mediterranean mountain areas is complex and difficult to predict as Mediterranean regions are characterized by a strong intra- and inter-annual precipitation variability and a strong climatic seasonality that lead to a very contrasted hydrological response along the year. Nonetheless, an improved understanding of the catchment hydrological functioning can be obtained from the analysis of solute dynamics in rainfall, stream water, soil water and groundwater. Dissolved organic carbon (DOC) dynamics at the catchment scale has been studied in many environments, but there are relatively few studies in Mediterranean mountain regions. With the objective of improving the knowledge of DOC dynamics in seasonal Mediterranean environments, rainfall, soil water, groundwater and stream water samples were taken on a regular basis, as well as during rainfall-runoff events along a 26 month period in the Can Vila research catchment (NE Spain, 42º 12'N, 1º 49'E). Detailed distributed hydrometric measurements (precipitation, discharge, soil moisture and water table level) were obtained during the same period. Using these data we characterized the DOC dynamics in the different hydrological compartments and analyzed the factors which affect them. We also analyzed the DOC dynamics during rainfall-runoff events to assess possible differences in the hydrological functioning of the catchment between dry and wet conditions. Preliminary results suggest that at seasonal scale DOC dynamics of stream water and groundwater are affected by discharge and water table dynamics, respectively, as DOC dynamics follow the hydrological trends. During rainfall-runoff events, an increase of DOC concentration was observed in the stream. However the DOC dynamics during floods showed some differences between events suggesting some changes in the dominant runoff processes.

Roig-Planasdemunt, Maria; Llorens, Pilar; Latron, Jérôme

2014-05-01

238

Self Organising Maps and Canonical Correlation Analysis: application to catchment classification and PUB  

NASA Astrophysics Data System (ADS)

The scientific community indicates that the formulation of objective criteria for catchment classification is one of the main objectives for obtaining a better interpretation and representation of the spatiotemporal variability of streamflows. A promising approach to catchment classification, and in general to pattern recognition, makes use of unsupervised neural networks, and in particular Self Organising Maps (SOM), which organise input data through non-linear techniques depending on the intrinsic similarity of the data themselves (see e.g., Toth, HESS, 2009). This study considers a set of some 300 Italian catchments scattered nationwide, for which several descriptors of the streamflow regime and geomorphoclimatic characteristics are available. We qualitatively and quantitatively compared a reference classification, RC, with three alternative classifications, ACs. RC was identified by using indices of the streamflow regime as input to SOM, whereas ACs were identified on the basis of catchment descriptors available for ungauged basins. The first AC adopts the available catchment geomorphoclimatic descriptors as input to SOM. The other ACs were identified by applying SOM to sets of derived variables, which were obtained by applying Principal Component Analysis (PCA, second AC) and Canonical Correlation Analysis (CCA, third AC) to the available indices. First, the similarity between each AC and RC is assessed qualitatively, analysing how the study catchments were grouped together. Second, ACs are compared with RC in terms of accuracy of streamflow prediction. In particular, we performed an extensive cross-validation procedure to quantify nationwide the accuracy of estimates of the mean annual flow, mean annual flood and flood quantiles associated with given exceedance probabilities. Results of the study show that CCA can significantly improve the effectiveness of SOM classifications for the estimation of streamflow regime in ungauged basins.

di Prinzio, Monica; Castellarin, Attilio; Toth, Elena

2010-05-01

239

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

240

Effects of urban stormwater infrastructure on frequency, magnitude and scaling characteristics of runoff, and their implications for the transport of particulate material in arid catchments  

NASA Astrophysics Data System (ADS)

Over recent decades urbanization has occurred rapidly, particularly in the arid and semi-arid southwestern USA. Major changes in ecosystem structure occur during urbanization, including changes in land cover and drainage networks. Changes in the connectivity of hydrological flow paths result from the construction of stormwater infrastructure, which in some instances increases flow connectivity and in others decrease it. In this study we investigate the effects of urbanization, specifically different types of stormwater infrastructure, on the frequency, magnitude and scaling characteristics of runoff in urban catchments. We evaluate consequences of these runoff characteristics for hydrologically mediated transport of particulate material and nutrient transport within urban catchments. A series of nested catchments was instrumented to monitor flow and water quality in the Indian Bend Wash catchment, Scottsdale, AZ. Catchments range in area from 6 to >17,000 ha and are predominantly residential. At the smallest spatial scales, catchments of comparable size represent different types of stormwater infrastructure, allowing us to isolate the effects of specific types of stormwater infrastructure on flow dynamics and material transport. Stormwater infrastructure in larger catchments (> 100 ha) is heterogeneous, allowing us to investigate the scaling characteristics of runoff and material transport. Results show that catchments with highly connected stormwater infrastructure (such as pipes) generate runoff in response to very low rainfall amounts, contributing to frequent flushing of particulate materials. The combination of high flow velocities and frequent flushing renders material transport within these catchments supply limited. In contrast, in catchments with disconnected stormwater infrastructure (such as retention basins), more rainfall is required to generate a runoff response at the catchment outlet, and runoff is less flashy than in highly connected catchments. Runoff from catchments occurs less frequently and runoff coefficients decrease with increases in spatial scale, which is comparable with scaling behaviour observed in non-urban aridland catchments. Across all sites, and across all spatial scales, the proportion of nutrients in particulate forms increases at high discharges because of the increased capacity of flow to entrain and transport particulate material. The total export of dissolved and particulate materials from catchments increases with spatial scale, but export of materials per unit area actually decreases with an increase in spatial scale. Thus, more frequent flow events at small spatial scales redistribute particulate materials within catchments, which are temporarily stored and later exported from the catchments during high-magnitude, infrequent flow events that occur over larger spatial scales.

Turnbull, L.; Hale, R. L.; Earl, S.; Grimm, N. B.; Childers, D. L.

2011-12-01

241

Recasting catchment water balance for water allocation between human and environmental purposes  

NASA Astrophysics Data System (ADS)

Rebalancing water allocation between human consumptive uses and the environment in water catchments is a global challenge. The conventional water balance approach which partitions precipitation into evapotranspiration (ET) and surface runoff supports the optimization of water allocations among different human water use sectors under the cap of water supply. However, this approach is unable to support the emerging water management priority issue of allocating water between societal and ecological systems. This paper recast the catchment water balance by partitioning catchment total ET into ET for the society and ET for the natural ecological systems, and estimated the impacts of water allocation on the two systems in terms of gross primary productivity (GPP), in the Murray-Darling Basin (MDB) of Australia over the period 1900-2010. With the recast water balance, the more than 100 year water management in the MDB was divided into four periods corresponding to major changes in basin management: period 1 (1900-1956) expansion of water and land use by the societal system, period 2 (1956-1985) maximization of water and land use by the societal system, period 3 (1985-2002) maximization of water diversion for the societal system, and period 4 (2002-present) rebalancing of water and land use between the societal and ecological systems. The recast water balance provided new understandings of the water and land dynamics between societal and ecological systems in the MDB, and it highlighted the experiences and lessons of catchment water management in the MDB over the last more than 100 years. The recast water balance could serve as the theoretical foundation for water allocation to keep a dynamic balance between the societal and ecological systems within a basin for sustainable catchment development. It provides a new approach to advance the discipline of socio-hydrology.

Zhou, S.; Huang, Y.; Wei, Y.; Wang, G.

2015-01-01

242

A modern analog of past climatic impacts on sedimentary processes and landscape evolution in an intermontane basin: The Del Medio fan, NW Argentina  

NASA Astrophysics Data System (ADS)

The combined effects of tectonic and climatic forcing govern the evolution of landscapes, setting the scale of topographic relief and the pace of landscape changes over time. Tectonic uplift or changes in precipitation regimes can fundamentally modify erosional processes and sediment flux from hillslopes, change river profiles, and ultimately impact depositional systems downstream. The complexity of the response, however, often means that we cannot predict a priori how a given landscape will react to future changes in climate, or how it responded in the past to multiple episodes of climate change. The Del Medio catchment is located in the southern part of the Humahuaca Basin, an intermontane valley within the Eastern Cordillera in transition to the Puna Plateau. This area coincides with a climatic and vegetation divide between a sub-humid environment downstream and the semi-arid upper Humahuaca Basin. An extensive fan sourced in the Del Medio catchment covers ca. 18.6 km2 of the basin outlet. The fan stratigraphy and surface morphology suggest that the fan dynamics are dominated by debris-flow processes. The surface comprises abandoned channels, levees and lobes, while exposed sections in channel cuts reveal unsorted, matrix-dominated deposits, with individual boulders reaching a diameter of 5 m. To investigate rates and timing of the Del Medio fan evolution, we analyzed cosmogenic 10Be concentrations on the surfaces of large boulders from the fan surface, river sands in active channels, a depth profile, and bedrock exposed atop the drainage basin margins. Our preliminary CRN results illustrate the rapid rate at which the active fan surface is subject to change, with each of the 11 analyzed boulder samples providing ages of < 200 years. In addition, river sands record very high denudation rates that range from several mm/yr to tens of mm/yr, despite bedrock denudation rates from the basin margins of only 0.04 mm/yr. These contrasting denudation rates likely result from frequent landsliding and debris flows along the steep slopes of the catchment area, which generates sediment of near-zero cosmogenic nuclide concentrations. Farther upstream in the more arid Humahuaca Basin, abandoned fluvial terrace sequences that exceed 100 m in thickness have been linked to wetter episodes during the late Quaternary. Within those fills, preliminary paleo-denudation rates reach values similar to those currently observed in the Del Medio catchment, while modern denudation rates from river sands are similar to the low rates observed from bedrock samples. Taken together, these observations indicate that the Del Medio fan could be a modern analog of those older fill sequences, providing a unique opportunity to link present-day processes in the Del Medio catchment to those that were likely active in the past during wetter climate episodes in the Humahuaca Basin.

Savi, Sara; Schildgen, Taylor F.; Tofelde, Stefanie; Wittmann, Hella; Strecker, Manfred

2014-05-01

243

Goulburn River experimental catchment data set  

Microsoft Academic Search

This paper describes the data set from the 6540-km2 Goulburn River experimental catchment in New South Wales, Australia. Data have been archived from this experimental catchment since its inception in September 2002. Land use in the northern half of the catchment is predominantly cropping and grazing on basalt-derived soils, with the south being cattle and sheep grazing on sandstone-derived soils;

Christoph Rüdiger; Greg Hancock; Herbert M. Hemakumara; Barry Jacobs; Jetse D. Kalma; Cristina Martinez; Mark Thyer; Jeffrey P. Walker; Tony Wells; Garry R. Willgoose

2007-01-01

244

Model development based on a landscape oriented catchment unit concept  

NASA Astrophysics Data System (ADS)

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 regional hydrological modelling using PRMS/MMS in the drainage basin of the river Bröl, Germany. Hydrological Processes 9, 424-436. Merz, R., Blöschl, G. (2009a): process controls on the statistical flood moments - a data based analysis. Hydrological Processes 23, 675-696. Merz, R., Blöschl, G. (2009b): A regional analysis of event runoff coefficients with respect to climate and catchment characteristics in Austria. Water Resources Research, Vol. 45, W01404, doi:10.1029/2008WR007163, 2009. Reszler, C. Komma, J., Blöschl, G., Gutknecht, D. (2008): Dominante Prozesse und Ereignistypen zur Plausibilisierung flächendetaillierter Niederschlag-Abflussmodelle. Hydrologie und Wasserbewirtschaftung 52, 120-131 Samuel, J.M., Sivapalan, M., Struthers, I. (2008): Diagnostic analysis of water balance variability: A comparative modeling study of catchments in Perth, Newcastle, and Darwin, Australia. Water Resources Research, Vol. 44, W06403, doi.10.1029/2007WR006694, 2008. Schmocker_Fackel, P., Scherrer, S. (2007): Identifying runoff processes on the plot and catchment scale. Hydrol. Earth Syst. Sci. 11, 891-906

Cárdenas Gaudry, María.; Gutknecht, Dieter

2010-05-01

245

Influence of geology, regolith and soil on fluid flow pathways in an upland catchment in central NSW, Australia  

NASA Astrophysics Data System (ADS)

Influence of geology, regolith and soil on fluid flow pathways in an upland catchment in central NSW, Australia. Tony Bernardi and Leah Moore Dryland Salinity Hazard Mitigation Program (DSHMP), University of Canberra, ACT 2601, AUSTRALIA The diversity of salt expression in central NSW has defied classification because salt expression, mobilisation and transport is highly variable and is typically site specific. Hydrological models are extensively used to simulate possible outcomes for a range of land use changes to mitigate the mobilisation and transport of salt into the streams or across the land surface. The ability of these models to mimic reality can be variable thereby reducing the confidence in the models outputs and uptake of strategic management changes by the community. This study focuses on a 250 ha semi-arid sub-catchment of Little River catchment in central west NSW in the Murray-Darling Basin, Australia. We propose that an understanding the structure of the landforms and configuration of rock, regolith and soil materials at the study site influences fluid flow pathways in the landscape and can be related to observed variations in the chemical composition and salinity of surface and aquifer water. Preliminary geological mapping of the site identified the dominant rock type as a pink and grey dacite and in localised mid-slope areas, a coarsely crystalline biotite-phyric granodiorite. Samples were taken at regular intervals from natural exposures in eroded stream banks and in excavations made during the installation of neutron moisture meter tubes. In order to establish mineral weathering pathways, samples were taken from the relatively unweathered core to the outer weathered 'onion skins' of corestones on both substrates, and then up through the regolith profile, including the soil zone, to the land surface. X-ray diffraction (XRD) analysis and X-ray fluorescence (XRF) was conducted on the rock and soil/saprock samples. Electromagnetic induction (EMI) profile data were compiled from previous work with colleagues in this area. Preliminary interpretation of the mapping and the geophysics is that there is a three-layer framework for groundwater modelling: fractured granitic rock with an irregular upper surface, finer-grained (volcanic) rock that has either mantled the older granite or has been intruded into, and a weathering profile developed in relation to the land surface. More careful interpretation of the intervals that shallow and deep piezometers and shallow and deep bores are sampling indicates that variability in water chemistry between holes can, in part, be explained because they are sampling different materials in the sub-surface geology/regolith geology. Quartz is a relatively resistant phase throughout the profiles. For both substrates there is a decrease in the feldspar in increasingly weathered regolith materials, with a corresponding increase in kaolinite clay. There is increased homogenisation of the profile, and some horizonation due to pedogenic processes (e.g. bioturbation, illuviation of fines down profile) nearer the land surface. This results in a concentration of more resistant phases (quartz and remnant primary feldspar as sands) at the land surface over the granitic substrate, however kaolinite persists in the profile over the finer substrate. The presence of measurable ferruginous oxides and sesquioxides relates to localised percolation of oxidising fluids through the profiles. Understanding the configuration and composition of rocks and regolith materials in the Baldry catchment facilitates interpretation of observed patterns in hydrological analyses.

Bernardi, Tony

2014-05-01

246

Hydrograph prediction in ungauged basins - a comparative assessment of studies  

NASA Astrophysics Data System (ADS)

The objective of this assessment is to compare studies predicting runoff hydrographs in ungauged catchments. The aim is to learn from the similarities and differences between catchments in different places, and to interpret the differences in performance in terms of the underlying climate-landscape controls. The assessment is performed at two levels. The Level 1 assessment is a meta-analysis of 33 studies reported in the literature involving 3874 catchments. The Level 2 assessment consists of a more focused and detailed analysis of individual basins from selected studies from Level 1 in terms of how the leave-one-out cross-validation performance depends on climate and catchment characteristics as well as on the chosen regionalisation method. The results indicate that runoff hydrograph predictions in ungauged catchments tend to be more accurate in humid than in arid catchments and more accurate in large than in small catchments. The dependence of performance on elevation differs by regions and depends on how aridity varies with elevation and air temperature. The effect of parameter regionalisation method on model performance differs between studies. However, there is a tendency towards a somewhat lower performance of regressions than other methods in those studies that apply different methods in the same region. In humid catchments spatial proximity and similarity methods perform best while in arid catchments similarity and parameter regression methods perform slightly better. For studies with a large number of catchments (dense stream gauge network) there is a tendency for spatial proximity and geostatistics to perform better than regression or regionalisation based on simple averaging of model parameters from gauged catchments. There was no clear relationship between predictive performance and the number of regionalised model parameters. The implications of the findings are discussed in the context of model building.

Parajka, Juraj; Viglione, Alberto; Rogger, Magdalena; Salinas, Jose Luis; Sivapalan, Murugesu; Bloeschl, Guenter

2013-04-01

247

The impact of land management in agricultural catchments on groundwater pollution levels  

NASA Astrophysics Data System (ADS)

Agricultural activity results in water pollution from nitrogen and phosphorus compounds. Increased concentrations of nitrogen compounds pose a threat to animal and human health. The purpose of this study was to determine the impact of agriculture in a catchment basin on the level of groundwater pollution from biogenic compounds. Spatial analysis of the land cover was conducted using a GIS and was based on data from the Corine Land Cover databases.

Matysik, Magdalena

2014-10-01

248

The hydrological regime of a forested tropical Andean catchment  

NASA Astrophysics Data System (ADS)

The hydrology of tropical mountain catchments plays a central role in ecological function, geochemical and biogeochemical cycles, erosion and sediment production, and water supply in globally important environments. There have been few studies quantifying the seasonal and annual water budgets in the montane tropics, particularly in cloud forests. We investigated the water balance and hydrologic regime of the Kosñipata catchment (basin area: 164.4 km2) over the period 2010-2011. The catchment spans over 2500 m in elevation in the eastern Peruvian Andes and is dominated by tropical montane cloud forest with some high-elevation puna grasslands. Catchment-wide rainfall was 3112 ± 414 mm yr-1, calculated by calibrating Tropical Rainfall Measuring Mission (TRMM) 3B43 rainfall with rainfall data from nine meteorological stations in the catchment. Cloud water input to streamflow was 316 ± 116 mm yr-1 (9.2% of total inputs), calculated from an isotopic mixing model using deuterium excess (Dxs) and ?D of waters. Field streamflow was measured in 2010 by recording height and calibrating to discharge. River run-off was estimated to be 2796 ± 126 mm yr-1. Actual evapotranspiration (AET) was 688 ± 138 mm yr-1, determined using the Priestley and Taylor-Jet Propulsion Laboratory (PT-JPL) model. The overall water budget was balanced within 1.6 ± 13.7%. Relationships between monthly rainfall and river run-off follow an anticlockwise hysteresis through the year, with a persistence of high run-off after the end of the wet season. The size of the soil and shallow groundwater reservoir is most likely insufficient to explain sustained dry-season flow. Thus, the observed hysteresis in rainfall-run-off relationships is best explained by sustained groundwater flow in the dry season, which is consistent with the water isotope results that suggest persistent wet-season sources to streamflow throughout the year. These results demonstrate the importance of transient groundwater storage in stabilising the annual hydrograph in this region of the Andes.

Clark, K. E.; Torres, M. A.; West, A. J.; Hilton, R. G.; New, M.; Horwath, A. B.; Fisher, J. B.; Rapp, J. M.; Robles Caceres, A.; Malhi, Y.

2014-12-01

249

Catchment classification by means of hydrological models  

NASA Astrophysics Data System (ADS)

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 for catchment description and clustering. Hence, the classes do not only represent a distinctive hydrological regime, but also provide information on specific quantitative aspects that are directly linked to a certain model structure. The clustering that is based on model structures or model parameters are validated by the classifications based on SOM and are thus related to physiographic and climatic catchment properties and runoff behaviour, which provides insight into catchment functioning. Clustering based on model structures can be a fast and simple way of catchment classification. A database consistently relates input data and output data; model structures and model performance and allows formulating distinctive processes that are attached to a class. Thus, the final result of the study is a powerful classification tool that helps to formulate generalizations based on observations and testable hypotheses (i.e. model structures).

Hellebrand, Hugo; Ley, Rita; Casper, Markus

2013-04-01

250

Characterizing hydrologic change through catchment classification  

NASA Astrophysics Data System (ADS)

There has been an intensive search in recent years for suitable strategies to organize and classify the very heterogeneous group of catchments that characterize our landscape. One strand of this work has focused on testing the value of hydrological signatures derived from widely available hydro-meteorological observations for this catchment classification effort. Here we extend this effort by organizing 314 catchments across the contiguous US into 12 distinct clusters using six signature characteristics for a baseline decade (1948-1958, period 1). We subsequently develop a regression tree and utilize it to classify these catchments for three subsequent decades (periods 2-4). This analysis allows us to assess the movement of catchments between clusters over time, and therefore to assess whether their hydrologic similarity/dissimilarity changes. We find examples in which catchments initially assigned to a single class diverge into multiple classes (e.g., midwestern catchments between periods 1 and 2), but also cases where catchments from different classes would converge into a single class (e.g., midwestern catchments between periods 2 and 3). We attempt to interpret the observed changes for causes of this temporal variability in hydrologic behavior. Generally, the changes in both directions were most strongly controlled by changes in the water balance of catchments characterized by an aridity index close to one. Changes to climate characteristics of catchments - mean annual precipitation, length of cold season or the seasonality of precipitation throughout the year - seem to explain most of the observed class transitions between slightly water-limited and slightly energy-limited states. Inadequate temporal information on other time-varying aspects, such as land use change, limits our ability to further disentangle causes for change.

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

2014-01-01

251

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

NASA Astrophysics Data System (ADS)

This study used biomarkers such as n-alkanes, especially focused on the long chain n-alkanes and some diagnostic indexes derived from abundance, to elucidate molecular changes in the contribution of organic matter to the sediments, especially terrestrial vegetation surrounding continental areas around of Alfonso basin in response to climate change, particularly changes in the hydrological cycle. The results show that in general the n-alkanes of organic matter (OM) of Alfonso basin sediments are composed of a mixture of waxes derived from phytoplankton and terrestrial plants, with a greater contribution from phytoplankton compare to terrestrial vegetation, in the oldest part of the record, associated with a marine productivity increased period favored by rainfall. Maximum abundance of C29, and high values of C27/C31 ratio indicate leaves from trees as a source wax, probably succulents plants characteristic of arid zones, with C3 as one of their metabolic pathway, identified from mean ACL values around 29.5. The low CPI index indicates contamination and microbial communities as a possible source of long chain n-alkanes, probably due to anoxic bottom conditions in Alfonso basin favor the development of these communities. Finally, it is suggested no change in the community, at least for the last ~ 3.5 ka BP, but increased cover vegetation (biomass) in southern California during periods of increased rainfall (from ~ 3.5 to ~ 1.7 ka BP). The ability of terrestrial plant communities to adapt for longer periods before being replaced by other species, when faced with gradual changes rather than rapid climate change is reflected in a few changes in its composition.

Ricaurte-Villota, Constanza; Gonzalez-Yajimovich, Oscar; Betancourt-Portela, Julian

2014-05-01

252

Storage as a Metric of Catchment Comparison  

USGS Publications Warehouse

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.

McNamara, J.P.; Tetzlaff, D.; Bishop, K.; Soulsby, C.; Seyfried, M.; Peters, N.E.; Aulenbach, Brent T.; Hooper, R.

2011-01-01

253

The geography of the Humber catchment  

Microsoft Academic Search

The geography of the Humber catchment is described in relation to the varied geology, relief, resources, industrial structure and location, agriculture and population distribution. The review of catchment characteristics is set within an historical perpective, with an evaluation of current and possible future trends in agriculture, population, industry and possible implications for river water quality.

Helen P. Jarvie; Colin Neal; Alice J. Robson

1997-01-01

254

Hydrogeochemical responses of forested catchments  

NASA Astrophysics Data System (ADS)

The AGU Chapman Conference on Hydrogeochemical Responses of Forested Catchments was held September 18-21, 1989, in Bar Harbor, Maine, and brought together geochemists with interests in determining the effects of different geochemical processes on resulting surface water chemistry and hydrologists with interests in explaining flow generation in catchments with the aim of fostering better communication between the two groups on the topic of geochemical and hydrological interactions in intermediate-size watersheds. An important point of consideration was the emphasis on intermediate-size watersheds, which we defined operationally as watersheds of sufficient size to yield flow and habitat suitable for supporting at least a marginal recreational fishery, for example, on the order of at least a few square kilometers in the northeast United States. This emphasis is important because it is the potential effects of pollutants, as modified by watershed geochemical and hydrological processes, in watersheds of this scale that drive much of the concern of the nation's regulatory agencies with regard to adverse environmental effects and required water quality legislation. A good example of this is the current concern over potential adverse effects of acidic deposition on surface water quality, especially in streams that support upland sport fisheries.

Robbins Church, M.; Hornberger, George; Driscoll, Charles; Sklash, Michael; Hemond, Harold

255

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

USGS Publications Warehouse

This data set represents the area of bedrock geology types in square meters compiled for every catchment of NHDPlus for the conterminous United States. The source data set is the "Geology of the Conterminous United States at 1:2,500,000 Scale--A Digital Representation of the 1974 P.B. King and H.M. Beikman Map" (Schuben and others, 1994). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

256

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

USGS Publications Warehouse

This data set represents the average population density, in number of people per square kilometer multiplied by 10 for the year 2000, compiled for every catchment of NHDPlus for the conterminous United States. The source data set is the 2000 Population Density by Block Group for the Conterminous United States (Hitt, 2003). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMottem, Andrew E.

2010-01-01

257

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

USGS Publications Warehouse

This data set represents the area of each level 3 nutrient ecoregion in square meters, compiled for every catchment of NHDPlus for the conterminous United States. The source data are from the 2002 version of the U.S. Environmental Protection Agency's (USEPA) Aggregations of Level III Ecoregions for National Nutrient Assessment & Management Strategy (USEPA, 2002). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

258

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

USGS Publications Warehouse

This dataset represents the area of each physiographic province (Fenneman and Johnson, 1946) in square meters, compiled for every catchment of NHDPlus for the conterminous United States. The source data are from Fenneman and Johnson's Physiographic Provinces of the United States, which is based on 8 major divisions, 25 provinces, and 86 sections representing distinctive areas having common topography, rock type and structure, and geologic and geomorphic history (Fenneman and Johnson, 1946). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

259

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

USGS Publications Warehouse

This data set represents the area of surficial geology types in square meters compiled for every catchment of NHDPlus for the conterminous United States. The source data set is the "Digital data set describing surficial geology in the conterminous US" (Clawges and Price, 1999). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

260

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

USGS Publications Warehouse

This data set represents the estimated area of level 3 ecological landscape regions (ecoregions), as defined by Omernik (1987), compiled for every catchment of NHDPlus for the conterminous United States. The source data set is Level III Ecoregions of the Continental United States (U.S. Environmental Protection Agency, 2003). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

261

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

USGS Publications Warehouse

This data set represents the area of Hydrologic Landscape Regions (HLR) compiled for every catchment of NHDPlus for the conterminous United States. The source data set is a 100-meter version of Hydrologic Landscape Regions of the United States (Wolock, 2003). HLR groups watersheds on the basis of similarities in land-surface form, geologic texture, and climate characteristics. The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

262

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

USGS Publications Warehouse

This data set represents estimated soil variables compiled for every catchment of NHDPlus for the conterminous United States. The variables included are cation exchange capacity, percent calcium carbonate, slope, water-table depth, soil thickness, hydrologic soil group, soil erodibility (k-factor), permeability, average water capacity, bulk density, percent organic material, percent clay, percent sand, and percent silt. The source data set is the State Soil ( STATSGO ) Geographic Database (Wolock, 1997). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River Basins (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-Atlantic River basins, contains NHDPlus Production Units 1 and 2. MRB2, covering the South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

263

Geomorphological characterization of endorheic basins in northern Chile  

NASA Astrophysics Data System (ADS)

Quantitative geomorphology regroups a large number of interesting tools to characterize natural basins across scales. The application of these tools to several river basins allows the description and comparison of geomorphological properties at different spatial scales as oppose to more traditional descriptors that are typically applied at a single scale, meaning the catchment scale. Most of the recent research using these quantitative geomorphological tools has focused on open catchments and no specific attention has been given to endorheic basins, and the possibility of having particular features that distinguish them from exorheic catchments. The main objective of our study is to characterize endorheic basins and investigate whether these special geomorphological features can be identified. Because scaling invariance is a widely observed and relatively well quantified property of open basins, it provides a suitable tool to characterize differences between the geomorphology of closed and open basins. Our investigation focuses on three closed basins located in northern Chile which describe well the diversity in the geomorphology and geology of this arid region. Results show that endhoreic basins exhibit different slope-area and flow paths sinuosity regimes compared to those observed in open basins. These differences are in agreement with the particular self-similar behavior across spatial scales of the Euclidean length of subcatchments, as well as the Hack's law and Horton's ratios. These regimes imply different physical processes inside the channel network regardless of the basin area, and they seem to be related to the endorheic character of these basins. The analysis of the probability density functions of contributing areas and lengths to the lower region shows that the hypothesis of self-similarity can also be applied to closed basins. Theoretical expressions for these distributions were derived and validated by the data. Future research will focus on (1) applying similar analyses in other locations and comparing the results, and (2) understanding and modeling the effects of groundwater in forming the landscape of these arid regions.

Dorsaz, J.; Gironas, J. A.; Escauriaza, C. R.; Rinaldo, A.

2011-12-01

264

18 CFR 806.11 - Preliminary consultations.  

Code of Federal Regulations, 2010 CFR

...and Water Resources SUSQUEHANNA RIVER BASIN COMMISSION REVIEW AND APPROVAL OF PROJECTS Application Procedure § 806.11 Preliminary consultations. (a) Any project sponsor of a project that is or may be subject to...

2010-04-01

265

Quantifying denudation rates in Mediterranean margin catchments: the Gulf of Lion and East-Corsica case-study  

NASA Astrophysics Data System (ADS)

Margins are the place of transfer, deposit and erosion of sediments whose geometries are controlled by sea-level fluctuations, vertical movements and sedimentary fluxes. Surface processes (sedimentation, denudation) and deep-sea dynamic are also intimately linked. Due to the numerous data acquired over the last 10 years, the Gulf of Lion and East-Corsica margins could be considered as privileged studied areas to understand the relationships between denudation, sedimentation and associated vertical displacements. The quantification of denudation rates on these margins catchments, using offshore and onshore data aims to improve the understanding of the temporal and spatial evolution of denudation processes in their sedimentation and geodynamic evolution in a large basin (Gulf of Lion) and in a small confined basin (Golo margin; East-Corsica) during the Quaternary. The Gulf of Lion is the northern passive margin of the Liguro-provençal basin, in western Mediterranean Sea. During the Quaternary, it receives sediments from catchments draining several structural domains, as Alps, Pyrenees and Massif Central, for a drainage area of about 120,000 km^2. The East-Corsica corresponds to the western passive margin of the Tyrrhenian basin. The main catchment (Golo River) size is about 100 times smaller than the Gulf of Lion and is composed by two main structural units: Hercynian granites in the upstream part and Alpine schists in the downstream part. In this study, we quantified Quaternary denudation rates using four independent methods: i) estimation of eroded volumes using DEMs; ii) compilation of present-day sediment load fluxes; iii) determination of catchment-scale cosmogenic denudation rate by measuring 10Be concentrations in sands at the catchment outlets or buried in boreholes; iv) quantification of sediment volumes deposited offshore. Our results show a good consistence between the four methods. The Inner Alps present the highest values of denudation (~ 700 m/Ma), compared to averaged much lower values in other domains (150-250 m/Ma in foreland Alps, 100-150 m/Ma in Corsica, about 100 m/Ma in Pyrenees and 55-75 m/Ma in Massif Central). The alpine domain provides at least 75 % of the eroded volume in the Gulf of Lion catchment. A quantitative geomorphologic approach highlights the main role of denudation processes in relief evolution for both studied areas. At a regional scale (Gulf of Lion catchment), we highlight an exponential correlation between mean catchment elevation and denudation rates suggesting the main role of uplift in areas glaciated during the LGM in the control of denudation rates. At a more local scale (East-Corsica), denudation rates seem to rely on lithologic and structural control.

Molliex, S.; Rabineau, M.; Jouet, G.; Bourles, D. L.; Freslon, N.; Leroux, E.; Moreau, J.; Aslanian, D.; Vella, C.

2013-12-01

266

Influence of basin connectivity on sediment source, transport, and storage within the Mkabela Basin, South Africa  

NASA Astrophysics Data System (ADS)

The management of sediment and other non-point source (NPS) pollution has proven difficult, and requires a sound understanding of particle movement through the drainage system. The primary objective of this investigation was to obtain an understanding of NPS sediment source(s), transport, and storage within the Mkabela Basin, a representative agricultural catchment within the KwaZulu-Natal Midlands of eastern South Africa, by combining geomorphic, hydrologic and geochemical fingerprinting analyses. The Mkabela Basin can be subdivided into three distinct subcatchments that differ in their ability to transport and store sediment along the axial valley. Headwater (upper catchment) areas are characterized by extensive wetlands that act as significant sediment sinks. Mid-catchment areas, characterized by higher relief and valley gradients, exhibit few wetlands, but rather are dominated by a combination of alluvial and bedrock channels that are conducive to sediment transport. The lower catchment exhibits a low-gradient alluvial channel that is boarded by extensive riparian wetlands that accumulate large quantities of sediment (and NPS pollutants). Fingerprinting studies suggest that silt- and clay-rich layers found within wetland and reservoir deposits of the upper and upper-mid subcatchments are derived from the erosion of fine-grained, valley bottom soils frequently utilized as vegetable fields. Coarser-grained deposits within these wetlands and reservoirs result from the erosion of sandier hillslope soils extensively utilized for sugar cane, during relatively high magnitude runoff events that are capable of transporting sand-sized sediment off the slopes. Thus, the source of sediment to the axial valley varies as a function of sediment size and runoff magnitude. Sediment export from upper to lower catchment areas was limited until the early 1990s, in part because the upper catchment wetlands were hydrologically disconnected from lower parts of the watershed during low to moderate flood events. The construction of a drainage ditch through a previously unchanneled wetland altered the hydrologic connectivity of the catchment, allowing sediment to be transported from the headwaters to the lower basin where much of it was deposited within riparian wetlands. The axial drainage system is now geomorphically and hydrologically connected during events capable of overflowing dams located throughout the study basin. The study indicates that increased valley connectivity partly negated the positive benefits of controlling sediment/nutrient exports from the catchment by means of upland based, best management practices.

Miller, J. R.; Mackin, G.; Lechler, P.; Lord, M.; Lorentz, S.

2013-02-01

267

The hydrological effects of fire in South African mountain catchments  

Microsoft Academic Search

Streamflow and its storm-flow elements in four catchments were analyzed by the paired catchment method for a response to fire. Prior to burning two of the catchments were vegetated with over-mature fynbos (the indigenous scrub vegetation of the southwestern Cape, South Africa), one was afforested with Pinus radiata and the fourth with Eucalyptus fastigata. One of the fynbos catchments was

D. F. Scott

1993-01-01

268

Impact of earthquake-triggered landslides on catchment sediment yield  

NASA Astrophysics Data System (ADS)

This study explores the role of seismic activity in explaining spatial and temporal variation in sediment export from the Siret basin in Romania. Based on long-term (>30 years) sediment export measurements for 38 subcatchments, we found that spatial variation in sediment yield (SY) is strongly correlated to the degree of seismic activity and catchment lithology. Combined, these factors explain 80% of the variation in SY. To investigate the role of earthquake-triggered landslides in explaining these correlations, we studied the temporal variability in sediment concentrations before and after the 7.4 Mw earthquake of 1977 for ten subcatchments. Despite the fact that this earthquake triggered many landslides, only one subcatchment showed a clear (3-fold) increase in sediment concentration per unit discharge after the earthquake. This shows that, although prolonged seismic activity strongly controls average SY, individual earthquakes do not necessarily affect sediment export at short timescales.

Vanmaercke, M.; Obreja, F.; Poesen, J.

2015-03-01

269

Impact of papyrus wetland encroachment on spatial and temporal variabilities of stream flow and sediment export from wet tropical catchments.  

PubMed

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 (358km(2)-2120km(2)), 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 106-137tonkm(-2)y(-1) versus 34-37tonkm(-2)y(-1)). We therefore argue that protecting and (where possible) rehabilitating these papyrus wetlands should be a corner stone of catchment management strategies in the Lake Victoria basin. PMID:25617700

Ryken, N; Vanmaercke, M; Wanyama, J; Isabirye, M; Vanonckelen, S; Deckers, J; Poesen, J

2015-04-01

270

Climatic warming, glacier recession and runoff from Alpine basins after the Little Ice Age maximum  

Microsoft Academic Search

Records of discharge of rivers draining Alpine basins with between 0 and ?? 70% ice cover, in the upper Aare and Rhone catchments, Switzerland, for the period 1894-2006 have been examined together with climatic data for 1866-2006, with a view to assessing the effects on runoff from glacierized basins of climatic warming coupled with glacier recession following the Little Ice

David N. Collins

2008-01-01

271

Water Environments: Anthropogenic Pressures and Ecosystem Changes in the Atlantic Drainage Basins of Brazil  

Microsoft Academic Search

Densely occupied drainage basins and coastal zones in developing countries that are facing economic growth are likely to suffer from moderate to severe environmental impacts regarding different issues. The catchment basins draining towards the Atlantic coast from northeastern to southern Brazil include a wide range of climatic zones and diverse ecosystems. Within its borders lies the Atlantic rain forest, significant

Marcia Marques; Monica F. da Costa; Maria Irles de O. Mayorga; Patrícia R. C. Pinheiro

2004-01-01

272

A preliminary assessment of streamflow gains and losses for selected stream reaches in the lower Guadalupe River Basin, Texas, 2010-12  

USGS Publications Warehouse

The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers–Fort Worth District, the Texas Water Development Board, the Guadalupe-Blanco River Authority, and the Edwards Aquifer Authority, investigated streamflow gains and losses in the lower Guadalupe River Basin during four selected base-flow periods in March 2010, April 2011, August 2011, and, for a stream reach between Seguin, Tex., and Gonzales, Tex., in September 2012. Major sources of streamflow in this basin include releases from Canyon Lake, inflow from major springs (Comal Springs, San Marcos Springs, and Hueco Springs), and base flow (groundwater seeping to streams). Streamflow and spring-flow data were collected at 35 streamflow-gaging stations (including 6 deployed for this study) during the base-flow periods. This report describes streamflow in the lower Guadalupe River Basin, which consists of the Guadalupe River drainage basin downstream from Canyon Lake to the Guadalupe River near Tivoli, Tex. Streamflow conditions in the lower Guadalupe River Basin were analyzed by computing surface-water budgets for reaches of the lower Guadalupe River and tributary streams. Streamflow gains and losses were mapped for reaches where the computed gain or loss was greater than the uncertainty in the computed streamflow at the upstream and downstream ends of the reach. During the March 15–21, 2010, base-flow period, five reaches had gains greater than the uncertainty in the computed streamflow, including reach 1 on the Guadalupe River, which gained 130 cubic feet per second (ft3/s), and reach 3 on the Comal River, which gained 359 ft3/s. Streamflow gains during March 2010 primarily were derived from (1) inflow from the Edwards aquifer outcrop, including Hueco Springs and Comal Springs; (2) flow conveyed through the alluvium of the streambed; (3) inflows from the Carrizo-Wilcox aquifer and the Yegua Jackson aquifer; and (4) groundwater inflows from the Gulf Coast aquifer, which are enhanced by seepage losses from Coleto Creek Reservoir. During this base-flow period, none of the reaches had a loss greater in magnitude than the uncertainty in the computed streamflow. During the April 10–16, 2011, base-flow period, three reaches had gains greater than the uncertainty in the computed streamflow. Among these three reaches were reach 1 on the Guadalupe River, which gained 40.7 ft3/s, and reach 3 on the Comal River, which gained 271 ft3/s—reaches where streamflow gains were also measured in March 2010. Streamflow gains during April 2011 primarily were derived from (1) inflow from the Edwards aquifer outcrop, including Hueco Springs and Comal Springs; and (2) inflows from the Carrizo-Wilcox aquifer. During this base-flow period, three reaches had losses greater in magnitude than the uncertainty in the computed streamflow. A reach of the Blanco River near Kyle, Tex. (reach 10), lost 18.7 cubic feet per second (ft3/s). Much of this loss likely entered the groundwater system through the numerous faults that intersect the stream channel northwest of Kyle. The reach that included the confluence of the Guadalupe and San Marcos Rivers (reach 17) lost 155 ft3/s, likely as recharge to the Sparta and Queen City aquifers. During the August 19–25, 2011, base-flow period, three reaches had gains greater than the uncertainty in the computed streamflow, including reach 3 on the Comal River (168 ft3/s gain), which was one of the reaches where gains in streamflow also were measured in March 2010 and April 2011. Streamflow gains in August 2011 were primarily from (1) inflows from Comal Springs, (2) inflows from the Yegua Jackson aquifer, and (3) groundwater inflows from the Gulf Coast aquifer, which are enhanced by seepage losses from Coleto Creek Reservoir. During this base-flow period, five reaches had losses greater in magnitude than the uncertainty in the computed streamflow. The reach including the confluence of the Guadalupe and Comal Rivers lost 82.8 ft3/s. Much of that loss likely seeped into the local groundwater system. The reach of the Guadalupe River south

Wehmeyer, Loren L.; Winters, Karl E.; Ockerman, Darwin J.

2013-01-01

273

Integrated flow and temperature modeling at the catchment scale  

NASA Astrophysics Data System (ADS)

Changes in natural stream temperature levels can be detrimental to the health of aquatic ecosystems. Water use and land management directly affect the distribution of diffuse heat sources and thermal loads to streams, while riparian vegetation and geomorphology play a critical role in how thermal loads are buffered. In many areas, groundwater flow is a significant contribution to river flow, particularly during low flows and therefore has a strong influence on stream temperature levels and dynamics. However, previous stream temperature models do not properly simulate how surface water-groundwater dynamics affect stream temperature. A coupled surface water-groundwater and temperature model has therefore been developed to quantify the impacts of land management and water use on stream flow and temperatures. The model is applied to the simulation of stream temperature levels in a spring-fed stream, the Silver Creek Basin in Idaho, where stream temperature affects the populations of fish and other aquatic organisms. The model calibration highlights the importance of spatially distributed flow dynamics in the catchment to accurately predict stream temperatures. The results also show the value of including temperature data in an integrated flow model calibration because temperature data provide additional constraints on the flow sources and volumes. Simulations show that a reduction of 10% in the groundwater flow to the Silver Creek Basin can cause average and maximum temperature increases in Silver Creek over 0.3 °C and 1.5 °C, respectively. In spring-fed systems like Silver Creek, it is clearly not feasible to separate river habitat restoration from upstream catchment and groundwater management.

Loinaz, Maria C.; Davidsen, Hasse Kampp; Butts, Michael; Bauer-Gottwein, Peter

2013-07-01

274

Influence of basin connectivity on sediment source, transport, and storage within the Mkabela Basin, South Africa  

NASA Astrophysics Data System (ADS)

The management of sediment and other non-point source (NPS) pollution has proven difficult, and requires a sound understanding of particle movement through the drainage system. The primary objective of this investigation was to obtain an understanding of NPS sediment source(s), transport, and storage within the Mkabela basin, a representative agricultural catchment within the KwaZulu-Natal Midlands of southeastern South Africa, by combining geomorphic, hydrologic and geochemical fingerprinting analyses. The Mkabela Basin can be subdivided into three distinct subcatchments that differ in their ability to transport and store sediment along the axial valley. Headwater (upper catchment) areas are characterized by extensive wetlands that act as significant sediment sinks. Mid-catchment areas, characterized by higher relief and valley gradients, exhibit few wetlands, but rather are dominated by a combination of alluvial and bedrock channels that are conducive to sediment transport. The lower catchment exhibits a low-gradient alluvial channel that is boarded by extensive riparian wetlands that accumulate large quantities of sediment (and NPS pollutants). Fingerprinting studies suggest that silt- and clay-rich layers found within wetland and reservoir deposits are derived from the erosion of fine-grained, valley bottom soils frequently utilized as vegetable fields. Coarser-grained deposits within both wetlands and reservoirs result from the erosion of sandier hillslope soils extensively utilized for sugar cane, during relatively high magnitude runoff events that are capable of transporting sand-sized sediment off the slopes. Thus, the source of sediment to the axial valley varies as a function of sediment size and runoff magnitude. Sediment export from the basin was limited until the early 1990s, in part because the upper catchment wetlands were hydrologically disconnected from lower parts of the watershed during low- to moderate flood events. The construction of a drainage ditch through a previously unchanneled wetland altered the hydrologic connectivity of the catchment, allowing sediment to be transported from the headwaters to the lower basin where much of it was deposited within the riparian wetlands. The axial drainage system is now geomorphically and hydrologically connected during most events throughout the study basin. The study indicates that increased valley connectivity partly negated the positive benefits of controlling sediment/nutrient exports from the catchment by means of upland based, best management practices.

Miller, J. R.; Mackin, G.; Lechler, P.; Lord, M.; Lorentz, S.

2012-09-01

275

Water Catchment and Storage Monitoring  

NASA Astrophysics Data System (ADS)

Sensors and Sensor Networks technologies provide the means for comprehensive understanding of natural processes in the environment by radically increasing the availability of empirical data about the natural world. This step change is achieved through a dramatic reduction in the cost of data acquisition and many orders of magnitude increase in the spatial and temporal granularity of measurements. Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) is undertaking a strategic research program developing wireless sensor network technology for environmental monitoring. As part of this research initiative, we are engaging with government agencies to densely monitor water catchments and storages, thereby enhancing understanding of the environmental processes that affect water quality. In the Gold Coast hinterland in Queensland, Australia, we are building sensor networks to monitor restoration of rainforest within the catchment, and to monitor methane flux release and water quality in the water storages. This poster will present our ongoing work in this region of eastern Australia. The Springbrook plateau in the Gold Coast hinterland lies within a World Heritage listed area, has uniquely high rainfall, hosts a wide range of environmental gradients, and forms part of the catchment for Gold Coast's water storages. Parts of the plateau are being restored from agricultural grassland to native rainforest vegetation. Since April 2008, we have had a 10-node, multi-hop sensor network deployed there to monitor microclimate variables. This network will be expanded to 50-nodes in February 2010, and to around 200-nodes and 1000 sensors by mid-2011, spread over an area of approximately 0.8 square kilometers. The extremely dense microclimate sensing will enhance knowledge of the environmental factors that enhance or inhibit the regeneration of native rainforest. The final network will also include nodes with acoustic and image sensing capability for monitoring higher level parameters such as fauna diversity. The regenerating rainforest environment presents a number of interesting challenges for wireless sensor networks related to energy harvesting and to reliable low-power wireless communications through dense and wet vegetation. Located downstream from the Springbrook plateau, the Little Nerang and Hinze dams are the two major water supply storages for the Gold Coast region. In September 2009 we fitted methane, light, wind, and sonar sensors to our autonomous electric boat platform and successfully demonstrated autonomous collection of methane flux release data on Little Nerang Dam. Sensor and boat status data were relayed back to a human operator on the shore of the dam via a small network of our Fleck™ nodes. The network also included 4 floating nodes each fitted with a string of 6 temperature sensors for profiling temperature at different water depths. We plan to expand the network further during 2010 to incorporate floating methane nodes, additional temperature sensing nodes, as well as land-based microclimate nodes. The overall monitoring system will provide significant data to understand the connected catchment-to-storage system and will provide continuous data to monitor and understand change trends within this world heritage area.

Bruenig, Michael; Dunbabin, Matt; Moore, Darren

2010-05-01

276

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

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.

Stein, C.L.

1985-09-01

277

Preliminary modelling results of an urban air quality model verifying the prediction of nitrogen dioxide, sulfur dioxide and ozone over the Sydney basin  

NASA Astrophysics Data System (ADS)

The air quality modelling system (HIRES-AIRCHEM) of The University of New South Wales is tested with regard to forecast distributions of sulfur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3) over the Sydney basin and surrounding area. This is achieved by assimilating the emissions inventory of the New South Wales State Environment Protection Authority. This inventory contains both road and non-road sources. The HIRES-AIRCHEM system was run over the greater Sydney metropolitan area for a four day period in February 1998. During this period O3 readings, in particular, exceeded the EPA’s threshold maximum of 80 ppb. The model forecasts of the NO2-, SO2- and O3-distributions verify well with the EPA’s monitored readings. Diurnal concentrations are greatest in the late afternoon, as expected, when photochemical processes are most active. Furthermore, the forecast spatial distribution of NO2 and SO2 shows maximum values radiating out along major roads from the Sydney CBD and other population centres. This is consistent with NO2 and SO2 being major pollutants associated with vehicular traffic. These promising results have significant implications for possible future use of the system as a tool for routinely assessing air quality.

Leslie, L. M.; Speer, M. S.

2004-09-01

278

Modelling hydrology and water quality in a Mediterranean catchment  

NASA Astrophysics Data System (ADS)

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 calibrated and then validated, obtaining satisfactory performance. The estimation of loads from diffuse sources was difficult due to limited data availability. Thus, it was only possible to include constant diffuse pollution concentrations at present. In spite of these limitations, the model captured rather well the dynamic of flow generation and was able to predict the range of nutrient concentrations in surface water. The contribution of urban areas to the polluting loads at catchment scale is relevant especially during the dry season.

Candela, Angela; Viviani, Gaspare

2010-05-01

279

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

NASA Astrophysics Data System (ADS)

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 deviate water out of the catchment and a badland area were parameterized in the SWAT model to finally calibrate the hydrology and the sediment yield of the catchment. The model was manually calibrated by a process of trial and error. Model performance during the calibration was evaluated using several statistical parameters, such as the Nash-Sutcliffe efficiency coefficient (NSE) and average runoff volume deviation (Dv). The hydrology was calibrated using continuous measured streamflow data from two gauge stations. The sediment yield calibration was based in specific sediment yield calculated from bathymetric surveys in the Barasona reservoir. The introduction of these improvements in the model performed better results than previous simulations enhancing the calibration of SWAT for the Barasona catchment. The final calibration of the model allows modeling water and sediment production closer to reality and therefore the study of the catchment processes would be more reliable.

Palazón, Leticia; Navas, Ana

2013-04-01

280

A Catchment-Based Hydrologic and Routing Modeling System with explicit river channels  

NASA Astrophysics Data System (ADS)

In this paper, we present a macroscale hydrologic modeling system with an explicit representation of storage and movement of water in river channels and floodplains. The overall modeling system, called the Catchment-Based Hydrologic and Routing Modeling System (CHARMS), is composed of a land surface model and a river routing model that operate on a network of hydrologic catchments (or watersheds). The land surface model in CHARMS is based on the National Center for Atmospheric Research Community Land Model. The river routing model in CHARMS generates river discharge by transporting runoff generated by the catchment-based CLM through the river network. The routing model uses information on channel cross-section geometry, derived from the 90 m Shuttle Radar Topography Mission digital elevation model, to simulate river discharge and the associated flow depth and inundation width. CHARMS was implemented over the Wabash River basin in the central United States (drainage area 72282 km2), and simulated streamflow was validated using daily observations. Simulated flow depth and inundation extent generally followed seasonal variations in observed flooding and droughts. Limitations of some of the assumptions and scaling factors used in this study and the issues that need to be addressed for a continental- or global-scale implementation of CHARMS are discussed. This paper serves as the foundation for a catchment-based, global land surface modeling framework that could incorporate spatiotemporal variations in surface water bodies, as well as satellite measurements of these variations.

Goteti, Gopi; Famiglietti, James S.; Asante, Kwabena

2008-07-01

281

Chloride circulation in a lowland catchment and the formulation of transport by travel time distributions  

NASA Astrophysics Data System (ADS)

Travel times are fundamental catchment descriptors that blend key information about storage, geochemistry, flow pathways and sources of water into a coherent mathematical framework. Here we analyze travel time distributions (TTDs) (and related attributes) estimated on the basis of the extensive hydrochemical information available for the Hupsel Brook lowland catchment in the Netherlands. The relevance of the work is perceived to lie in the general importance of characterizing nonstationary TTDs to capture catchment transport properties, here chloride flux concentrations at the basin outlet. The relative roles of evapotranspiration, water storage dynamics, hydrologic pathways and mass sources/sinks are discussed. Different hydrochemical models are tested and ranked, providing compelling examples of the improved process understanding achieved through coupled calibration of flow and transport processes. The ability of the model to reproduce measured flux concentrations is shown to lie mostly in the description of nonstationarities of TTDs at multiple time scales, including short-term fluctuations induced by soil moisture dynamics in the root zone and long-term seasonal dynamics. Our results prove reliable and suggest, for instance, that drastically reducing fertilization loads for one or more years would not result in significant permanent decreases in average solute concentrations in the Hupsel runoff because of the long memory shown by the system. Through comparison of field and theoretical evidence, our results highlight, unambiguously, the basic transport mechanisms operating in the catchment at hand, with a view to general applications.

Benettin, Paolo; Velde, Ype; Zee, Sjoerd E. A. T. M.; Rinaldo, Andrea; Botter, Gianluca

2013-08-01

282

Characterising phosphorus transfers in rural catchments using a continuous bank-side analyser  

NASA Astrophysics Data System (ADS)

A six-month series of high-resolution synchronous stream discharge and total phosphorus (TP) concentration data is presented from a 5 km2 agricultural catchment in the Lough Neagh basin, Northern Ireland. The data are hourly averages of 10-minute measurements using a new bankside, automatic, continuous monitoring technology. Three TP transfer "event-types" occur in this catchment: (1) chronic, storm independent transfers; (2) acute, storm dependent transfers; (3) acute, storm independent transfers. Event-type 2 transferred over 90% of the total 279 kg TP load in 39% of the total period; it corresponded to diffuse transfers from agricultural soils. Event-types 1 and 3, however, maintained the river in a highly eutrophic state between storm events and were characteristic of point source pollution, despite there being no major industrial or municipal point sources. Managing P transfers at the catchment scale requires a robust monitoring technology to differentiate between dynamic, multiple sources and associated event types and so enable a reliable assessment of the performance of mitigation measures, monitored at catchment outlets. The synchronous and continuous TP and discharge data series generated in this study demonstrate how this is possible.

Jordan, P.; Arnscheidt, A.; McGrogan, H.; McCormick, S.

2007-01-01

283

Forested Water Catchments in a Changing Environment  

Microsoft Academic Search

\\u000a In the past, headwater catchments have often been studied to elucidate the effect of forests on the water cycle. This has\\u000a been of interest since centuries and we recall here this historical context. We review the quantitative effects found in numerous\\u000a studies around the world, especially those from paired-catchment experiments. As a rule, they indicate a lower water yield\\u000a of

Patrick Schleppi

284

Determinants of Farm-level Adoption of Water Systems Innovations in Dryland Areas: The Case of Makanya Watershed in Pangani River Basin, Tanzania  

Microsoft Academic Search

Water system innovations such as rainwater harvesting involve abstraction of water in the upper catchments. Increasing adoption of rainwater harvesting in the riparian catchments could have hydrological impacts on downstream flows in the river basin, but it is assumed to have overall gains and synergies when efficient use of rainwater is optimized at farm-level. This paper examines the main determinants

Kenneth F. G. Masuki; Khamaldin D. Mutabazi; Siza D. Tumbo; Filbert B. Rwehumbiza; Amon Z. Mattee; Nuhu Hatibu

285

Using scale-dependent observational data for snow modelling in a glacierized catchment  

NASA Astrophysics Data System (ADS)

Snow cover distribution and melt are essential to understand and to predict runoff. However, the spatial heterogeneity of snow cover in complex terrain and the limited availability of observational data make distributed modelling of snow covered area (SCA) and of snow water equivalent (SWE) in alpine regions still a challenging task. A promising approach is the application of physically based distributed hydrological models coupled with ground observations and with new satellite products. However, the inherent complexity of advanced models and satellite products requires an accurate evaluation both at plot and at catchment scale before their operational use. In this context we evaluate the capability of the new model GEOtop 2.0 for the first time to simulate snow dynamics at plot and at catchment scale. Our study was performed in the upper Saldur basin (61 km²) in the Eastern Italian Alps during the period 2010 - 2013. At plot scale, simulated snow depths and SWE were calibrated against measured snow depth data from multiple measuring sites at different elevations (at 1930 m, at 1998 m, at 2450 m, and 3035 m a.s.l.) in and close to the Saldur basin. The evaluation was quantified by the statistical indices R² and the Nash-Sutcliffe efficiency. Different model parameterisations were evaluated by a manual sensitivity analysis of 11 key parameters controlling the snowpack and the meteorological input data. Most of these key parameters found to be sensitive for SWE and for snow depth were the ones controlling albedo decreasing and precipitation input. At catchment scale, simulated SCA of the upper Saldur basin was calibrated against the daily composite 250 m EURAC MODIS SCA (Notarnicola et al. 2013) and then validated against Landsat 7 ETM+ SCA (at 30 m resolution). The model evaluation was supported by a pixel-based calculation of overall accuracy (Parajka and Blöschl 2008) of total SCA in the upper Saldur basin. Additionally, the snow presence derived from simulated SCA and MODIS SCA was evaluated against measured snow depth as ground truth data derived from the measuring sites. The same parameterisations, which were sensitive at plot scale showed good agreement with MODIS SCA, in particular for single snow events in autumn. These results confirm that model parameters were successfully transferred from plot scale to catchment scale. However, less agreement was found in zones with forest and steep slopes greater than 45°. Further investigations are needed to assess the uncertainties both of the hydrological model but also of the MODIS composite product in relation to different thresholds of snow depths and cloud cover. Keywords: snow cover, hydrological modelling, MODIS, plot and catchment scale, uncertainty.

Engel, Michael; Bertoldi, Giacomo; Endrizzi, Stefano; Notarnicola, Claudia; Niedrist, Georg; Comiti, Francesco

2014-05-01

286

New understanding of the complexity of groundwater flow in Chalk catchments of the UK  

NASA Astrophysics Data System (ADS)

The Chalk is the largest aquifer in the UK accounting for more than half the groundwater used and nearly a quarter of the total public water supplied in England and Wales. Although the Chalk is a double porosity and permeability medium, transmission of water in the saturated zone depends largely on flow through fractures, the location and distribution of which are controlled by lithology and geological structure. These features operate on a number of spatial scales and so provide a range of flow pathways that can markedly affect both stream flow and water quality. In addition, overlying Palaeogene or superficial deposits can act as controls on recharge and zones of increased groundwater storage. As part of a major initiative on Lowland Catchment Research in the UK two Chalk sub-catchments, in the River Thames basin, the rivers Pang and Lambourn, have been the focus of an intensive set of studies. The catchments have been characterised using a multidisciplinary approach. This has resulted in an improved understanding of the way such catchments work and the mechanisms that control groundwater flow. The low fracture porosity gives rise to a low specific yield, which means that large fluctuations in water table elevation beneath the interfluves are not uncommon. Consequently, groundwater catchments differ from the topographic catchments and their size varies seasonally. This means, for example, that groundwater might be flowing to the River Pang in winter but to the River Thames in summer. It also means that various flow features in the catchment may be active at different locations and times during the year. Four flow systems have been identified, through a detailed analysis of the data; a shallow, but rapid flow system; a slower, deeper system; a very high velocity system developed in large diameter solution enhanced fractures and a system found in the river valley sediments. The interconnections between and within these systems can be poor and sometimes vary on a scale of a few metres. Dry valleys appear to be groundwater collectors so stream accretion therefore often occurs in a stepwise manner. Groundwater flow models commonly used in the management of Chalk catchments struggle to simulate this kind of complexity, and often utilise data from tests that may not be representative. There is an urgent need to develop models and supporting data that can better represent the local complexity of these natural environments and serve as management tools to help satisfy legislative drivers and inform habitat protection.

Peach, D.; Shand, P.; Gooddy, D.; Abesser, C.; Bloomfield, J.; Mathias, S.; Butler, A.; Williams, A.; Binley, A.; Wheater, H.

2006-12-01

287

Catchment classification based on characterisation of streamflow and precipitation time series  

NASA Astrophysics Data System (ADS)

The formulation of objective procedures for the delineation of homogeneous groups of catchments is a fundamental issue in both operational and research hydrology. For assessing catchment similarity, a variety of hydrological information may be considered; in this paper, gauged sites are characterised by a set of streamflow signatures that include a representation, albeit simplified, of the properties of fine time-scale flow series and in particular of the dynamic components of the data, in order to keep into account the sequential order and the stochastic nature of the streamflow process. The streamflow signatures are provided in input to a clustering algorithm based on unsupervised SOM neural networks, obtaining groups of catchments with a clear hydrological distinctiveness, as highlighted by the identification of the main patterns of the input variables in the different classes and the interpretation of their interrelations. In addition, even if no geographical, morphological nor climatological information is provided in input to the SOM network, the clusters exhibit an overall consistency as far as location, altitude and precipitation regime are concerned. In order to assign ungauged sites to such groups, the catchments are represented through a parsimonious set of morphometric and pluviometric variables, including also indexes that attempt to synthesise the variability and correlation properties of the precipitation time series, thus providing information on the type of weather forcing that is specific to each basin. Following a principal components analysis, needed for synthesizing and better understanding the morpho-pluviometric catchment properties, a discriminant analysis finally assigns the ungauged catchments, through a leave-one-out cross validation, to one of the above identified hydrologic response classes. The approach delivers a quite satisfactory identification of the membership of ungauged catchments to the streamflow-based classes, since the comparison of the two cluster sets shows a misclassification rate of around 20%. Overall results indicate that the inclusion of information on the properties of the fine time-scale streamflow and rainfall time series may be a promising way for better representing the hydrologic and climatic character of the study catchments.

Toth, E.

2013-03-01

288

Catchments as simple dynamical systems: A case study on methods and data requirements for parameter identification  

NASA Astrophysics Data System (ADS)

In many rainfall-runoff models at least some calibration of model parameters has to take place. Especially for ungauged or poorly gauged basins this can be problematic, because there is little or no data available for calibration. A possible solution to overcome the problems caused by data scarcity is to set up a measurement campaign for a short time period. With the employed approach based on the theory of Kirchner (2009), a model was developed and applied to the Rietholzbach catchment in Switzerland (Teuling et al., 2010, Seneviratne et al., 2012), with only two parameters. These two parameters describe a unique storage-discharge relation. The model is constructed such that the parameters can be determined not only with automatic calibration, but also by recession analysis and a priori from Boussinesq theory. The automatic calibration and the recession analysis have been fed with different selections of the full data record as well as with the full data record itself. For Boussinesq theory, catchment characteristics were given as required input. In the end, a comparison of the performance of the three different methods was made, and a comparison on the amount of data that is required by each of the three parameter identification methods. Melsen, L.A., Teuling, A.J., van Berkum, S.W., Torfs, P.J.J.F., Uijlenhoet, R. (2013) Catchments as simple dynamical systems: A case study on methods and data requirements for parameter identification, Water Resour. Res., under review References Kirchner, J.W. (2009), Catchments as simple dynamical systems: Catchment characterization, rainfall-runoff modeling, and doing hydrology backward, Water Resour. Res. 45:W02429. Seneviratne, S.I., I. Lehner, J. Gurtz, A.J. Teuling, H Lang, U. Moser, D. Grebner, L. Menzel, K. Schro, T. Vitvar, and M. Zappa (2012), Swiss prealpine Rietholzbach research catchment and lysimeter: 32 year time series and 2003 drought event, Water Resour. Res. 48:W06526. Teuling, A. J., I. Lehner, J. W. Kirchner, and S. I. Seneviratne (2010), Catchments as simple dynamical systems: Experience from a Swiss prealpine catchment, Water Resour. Res. 46: W10502.

Melsen, Lieke; Teuling, Adriaan; van Berkum, Sonja; Torfs, Paul; Uijlenhoet, Remko

2014-05-01

289

Development of regionalisation procedures using a multi-model approach for flow simulation in an ungauged catchment  

NASA Astrophysics Data System (ADS)

SummaryFlow simulation in ungauged catchments is presently regarded as one of the most challenging tasks in surface water hydrology. Many of the ungauged catchments are located in the headwaters of rivers in mountainous regions of the world having enormous potential for sustainable water resource development. However, due to inaccessibility, rugged and inhospitable terrain, and historical lack of foresight concerning the need to have these headwaters adequately gauged, their potential is not readily realizable. Many downstream sites also suffer from non-availability of site-specific data as even in countries having extensive networks of gauged stations data may not be available at sites where these are most needed. As predictive tools for water resources, water quality, natural hazard mitigation and water availability assessment are generally data-driven, the lack of adequate hydrometric records poses difficult problems for planners, engineers, managers, and stake-holders alike. In this study, a methodology is developed for flow simulation in ungauged catchments using a regionalisation and multi-model approach involving a suite of rainfall-runoff models and combination techniques. Daily observed hydrometeorological data for 12 French catchments are used for illustrating the procedures. Following a preliminary investigation of the regional homogeneity of that group of catchments, three regional flow simulation techniques are applied. Although all 12 catchments are gauged, initially each catchment is successively considered as being ungauged for the purpose of flow simulation in that catchment, their actual discharges being subsequently used for evaluating the performance of the flow estimation procedures for the catchment. The Nash-Sutcliffe efficiency index ( R2) is used for assessing and ranking the relative performances of the regionalisation-model couples to identify the most appropriate couple for the region. The final step of applying that couple to a truly ungauged (13th) catchment in the region is described. Results are presented and conclusions drawn on the efficacy of the regional-multi-model approach. Of the couples considered, the pooling method of regionalisation coupled with the conceptual soil moisture accounting and routing (SMAR) model is deemed to be the best for simulating flow in an ungauged catchment in the region.

Goswami, M.; O'Connor, K. M.; Bhattarai, K. P.

2007-02-01

290

A detailed model for simulation of catchment scale subsurface hydrologic processes  

NASA Technical Reports Server (NTRS)

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.

Paniconi, Claudio; Wood, Eric F.

1993-01-01

291

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)

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 facilitate the growth of centimeter-thick layers of euhedral carbonate and pyrrhotite. Rapidly formed, anhydrite-rich chimneys are present at the summit of the pagoda structures. In-situ laser ablation Sr isotopic analyses of calcite and anhydrite indicate that minerals within flanges precipitate from vent fluids with less than 5% seawater dilution, whereas minerals within the more permeable anhydrite-dominant chimneys precipitate from mixtures of vent fluid with up to 70% seawater.

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

292

High Park burn in South Fork Cache la Poudre Basin: Preliminary findings from spring and summer 2013 hydrologic and sedimentation monitoring  

NASA Astrophysics Data System (ADS)

The High Park fire burned over 35,000 ha within the Cache la Poudre basin in early summer 2012, including an eastern portion of the Little South Fork Cache la Poudre (SFCLP) watershed. Given the proximity of the burn and the implications for water quality supplied to Fort Collins and Greeley, CO, there is an expressed interest on the part of the cities for improved understanding of sediment loads in SFCLP and main stem Cache la Poudre River over the next few years. Prior to burning, data on sediment transport (suspended sediment and bedload) were collected by researchers from the US Forest Service, providing baseline information on sedimentation comparable to similar measurements taken after the High Park fire. In 2013, bedload was measured during snowmelt runoff using standard pressure-difference samplers identical to those used previously in 1989 and 1997. Turbidity sensors were deployed as a surrogate measure of suspended sediment concentration. This signal was calibrated using both grab samples (from a DH-48) and samples obtained from an automated water sampler triggered to collect during substantial increases in turbidity. Additional sampling stations were later established downstream of this site in conjunction with assessments of channel extension and sedimentation from severely burned hillslopes and gulches, one of which was mulched for erosion control in spring 2013. The primary source of post-fire sediment to the most upstream site is from Monument Gulch, located about 1 km upstream of the sampling location. Debris flows emanated from this gulch within a few weeks post-fire and delivered charcoal, ash, burned trees and inorganic sediment to the main stem SFCLP. Although snowmelt runoff was less than bankfull in 2013, there was a substantial amount of burned organic matter transported and collected in the bedload and suspended sediment samplers. Low intensity storms during summer caused a few sediment rich flows, though not to the extent of those in 2012. In this presentation, we present initial findings on differences in sediment loads attributed to the fire.

Ryan, S. E.; Dixon, M.; Rathburn, S. L.; Shahverdian, S.

2013-12-01

293

Assessing agriculture–water links at the basin scale: hydrologic and economic models of the São Francisco River Basin, Brazil  

Microsoft Academic Search

This article uses a basin-wide hydrologic model to assess the hydrologic and economic effects of expanding agriculture in the São Francisco River Basin, Brazil. It then uses a basin-wide economic model of agriculture to examine the effects of implementing water use regulations. Preliminary results suggest that substantially expanding agriculture would put pressure on some of the river's environmental flows. Agricultural

Marco Maneta; Marcelo Torres; Stephen A. Vosti; Wesley W. Wallender; Summer Allen; Luís H. Bassoi; Lisa Bennett; Richard Howitt; Lineu Rodrigues; Julie Young

2009-01-01

294

Comparison of New Airborne Gravity Results and GRACE Anomalies in the Thwaites Glacier Catchment of the Amundsen Sea Embayment, West Antarctica  

NASA Astrophysics Data System (ADS)

The West Antarctic Ice Sheet is a marine ice sheet of which 75% is resting on bedrock below sea level. This situation is highly unstable and as the climate warms, the potential for rapid discharge of the ice sheet grows. Examining the areas of the ice sheet that are most likely to react to changing climate is essential. The Amundsen Sea Embayment contains two of the most important outlet glaciers in West Antarctica: Thwaites and Pine Island Glaciers. These two glaciers have among the highest discharge velocities in West Antarctica and they lack large protective ice shelves, making them susceptible to warming ocean waters. The area is currently a target of interest for both GRACE and GLAS, as well as future land- and air-based surveys. To date, we have conducted the only large-scale geophysical survey over the catchment of Thwaites Glacier: an airborne survey completed during the austral summer 2004-2005. Over 43,500 line-kilometers of data were collected with a geophysical platform that included ice-penetrating radar, gravity, magnetics, laser and pressure altimetry, and GPS. Free-air gravity, in conjunction with magnetics and radar-derived subglacial topography, is capable of delineating microplate and rift boundaries as well as basin and volcano locations. A free-air gravity map of these structures helps ascertain the contribution of subglacial geology to the ice sheet's decay in the Thwaites Glacier catchment. The acquisition, reduction, and initial results of the airborne gravity survey will be presented and then compared to GRACE gravity anomalies. Extreme relief in ice surface elevation across the survey area necessitated short, smooth vertical altitude changes at survey block boundaries to maintain adequate flight altitude for the onboard ice-penetrating radar systems. Weather conditions sometimes required additional elevation changes or course corrections, producing significant aircraft motion during data acquisition. The impacts of these aircraft motions on the gravity data are discussed. The combination of GPS-derived horizontal accelerations with meter-mounted accelerometer measurements allows for the direct calculation of platform leveling errors, including leakage of the horizontal accelerations into the measured vertical gravity. We examine the magnitude and significance of platform leveling errors in relation to the overall survey resolution. Power spectral analysis of the gravity illuminates differences in the anomaly detection threshold over thick ice like that near Byrd Subglacial Basin versus over thin ice like that near the Thwaites Glacier grounding line. Filtering requirements for this situation are discussed. A preliminary free-air gravity map for the Thwaites Glacier catchment is presented along with error analysis and initial structural interpretations. The interpretations of the airborne regional gravity will be compared to GRACE static gravity anomalies over the same area of the catchment.

Diehl, T. M.; Holt, J. W.; Blankenship, D. D.; Richter, T. G.; Filina, I. Y.

2005-12-01

295

Hydrologic sensitivities of the Sacramento-San Joaquin River Basin, California, to global warming  

Microsoft Academic Search

The hydrologic sensitivities of four medium-sized mountainous catchments in the Sacramento and San Joaquin River basins to long-term global warming were analyzed. The hydrologic response of these catchments, all of which are dominated by spring snowmelt runoff, were simulated by the coupling of the snowmelt and the soil moisture accounting models of the U.S. National Weather Service River Forecast System.

Dennis P. Lettenmaier; Thian Yew Gan

1990-01-01

296

Hydrologic Sensitivities of the Sacramento-San Joaquin River Basin, California, to Global Warming  

Microsoft Academic Search

The hydrologic sensitivities of four medium-sized mountainous catchments in the Sacramento and San Joaquin River basins to long-term global warming were analyzed. The hydrologic response of these catchments, all of which are dominated by spring snowmelt runoff, were simulated by the coupling of the snowmelt and the soil moisture accounting models of the U.S. National Weather Service River Forecast System.

Dennis P. Lettenmaier; Thian Yew Gan

1990-01-01

297

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

NASA Astrophysics Data System (ADS)

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 the exercise, within each pair of basins, one is considered as "gauged" and the other one as "ungauged". Different spatial configurations of pairs of basins are compared. Results demonstrates the benefit of a well defined transfer function, as well as the importance of considering rainfall variability. Finally, through the assessment of transposition efficiency, this framework is presented as an original way to describe and understand hydrological similarities in catchment behavior.

de Lavenne, Alban; Cudennec, Christophe

2013-04-01

298

An Open-Source Approach for Catchment's Physiographic Characterization  

NASA Astrophysics Data System (ADS)

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 morphological parameters such as topological diameter, drainage density, Horton's ratios, concentration time, and many more, beside producing statistics on main channel and elevation and geometric features such as centroid's coordinates, rectangle containing the basin, etc. Exploiting Python libraries, such as Numpy and Matplotlib, it produces graphics like the hypsographic and hypsometric curve and the Width Function. The results are exported as a spreadsheet in CSV format and graphics as pngs. The advantages offered by the implementation in Python and GRASS are manifold. Python is a powerful scripting language with huge potential for researchers due to its relative simplicity, high flexibility and thanks to a broad availability of scientific libraries. GRASS, and as a consequence, r.basin, is platform independent, so that it is available for GNU/Linux, MS Windows, Mac, etc. Furthermore, the module is constantly maintained and improved according to users' feedback with the precious help of expert developers. The code is available for review under the official GRASS add-ons repository, allowing hydrologists and researchers to knowingly use, inspect, modify, reuse, and even incorporate it in other projects, such as web services.

Di Leo, M.; Di Stefano, M.

2013-12-01

299

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)

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 erosion or deposition is allowed for silt and clay. The model was first applied on the Madeira River basin, one of the major tributaries of the Amazon River (~1.4*106 km2) accounting for 35% of the suspended sediment amount annually transported for the Amazon river to the ocean. Model results agree with observed data, mainly for monthly and annual time scales. The spatial distribution of soil erosion within the basin showed a large amount of sediment being delivered from the Andean regions of Bolivia and Peru. Spatial distribution of mean annual sediment along the river showed that Madre de Dios, Mamoré and Beni rivers transport the major amount of sediment. Simulated daily suspended solid discharge agree with observed data. The model is able to provide temporaly and spatialy distributed estimates of soil loss source over the basin, locations with tendency for erosion or deposition along the rivers, and to reproduce long term sediment yield at several locations. Despite model results are encouraging, further effort is needed to validate the model considering the scarcity of data at large scale.

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

2012-04-01

300

Medium to long-term impacts of forest fires on slope to catchment-scale processes under current and future climate  

NASA Astrophysics Data System (ADS)

Forest wildfires can have important impacts on hydrological and soil erosion processes in burnt areas due to a variety of changes to soil properties and vegetation cover. The relevance of these impacts varies with wildfire characteristics, post-fire rainfall regime, and pre- and post-fire land management. The complex interactions between the various factors and processes have been one of the major obstacles to assessing wildfire impacts, particularly at larger spatial scales and over medium to long-term periods. This presentation will show ongoing research on a forested region in north-central Portugal, the Vouga river basin, aiming at: (i) quantifying medium and long-term impacts of wildfires, and (ii) estimating the impacts of climate change on wildfire regimes and assess their implications in terms of hydrological and soil erosion processes, and land degradation in general. The focus will be in the methodology and some preliminary results. To quantify medium and long-term impacts, existing information and data on the hydrological and soil erosion impacts of forest fires at small spatial and temporal scales has been compiled and analyzed. This information is the product of various international and national projects occurring since 1992, consisting of numerous observations on hydrological and erosion processes at the plot and hillslope. Ongoing work is also focusing on collecting data at the micro-catchment scale, and remote sensing imagery is being explored as a complementary information source, especially for large-scale landcover recovery patterns. The ultimate goal is to up-scale this information to meso and regional-scale catchments (100-250 km2) as well as to decade and longer periods. A simple modeling tool is being developed for impact assessment across spatial scales, addressing both on-site effects such as land degradation, and off-site effects such as flood risks and sediment export rates. Preliminary results for a slope-scale application of the model will be presented. The above-mentioned modeling tool, combined with climate change scenarios, will afterwards be used to estimate changes to wildfire regimes (frequency and intensity), and to assess their implications in terms of hydrological and soil erosion processes, and land degradation in general.

Nunes, João. Pedro; Alves Coelho, Celeste; Keizer, Jan Jacob

2010-05-01

301

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

NASA Astrophysics Data System (ADS)

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 regimes (i.e. low flow vs. flood periods). The behaviour of the PAHs mainly depends on their molecular mass. The lightest ones tend to quickly migrate to rivers whereas the heaviest slowly accumulate in soils throughout the low-flow period. Then, an increase in PAH export associated with sediment is observed during the winter floods, when rivers are heavily loaded with suspended matter. The downstream exports of PAHs are controlled by the main erosion processes that occurred in the catchments. Results show that PAH fluxes are more important when material is mostly supplied to rivers by soil surface erosion processes than when they are delivered by gully or riverbank erosion. Despite the reduction in PAH emissions since the 1960s, there is still a significant storage of PAHs in the upstream part of the Seine River basin. In this context, WFD objectives are unlikely to be reached by 2015.

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

2013-04-01

302

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)

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. Population rate of waste water treatment is 67 % in the total catchment area. Assumption case of 100% WWT was simulated and the result suggests that connection to public sewer system with WWTP is effective potential measure. TN emission in the Tone is higher than it in the Mur. Emission per capita is almost same level for both basin areas. Though the personal pollution stresses same as European basin area, the basin has huge population and activities to support their daily life. Agricultural activity and urban structure have great impacts on N emission and on the river water quality. Possible remedy for river pollution is construction of sewer system with waste water treatment. Agricultural activity is potential betterment factor. Comparison of Mur, Tone and assumption cases

Kogure, K.

2013-12-01

303

Tracer-based runoff modelling in a glacierized alpine catchment  

NASA Astrophysics Data System (ADS)

Water budget of high elevation catchments is dominated by snow and glacier runoff contributions. However, climate change is rapidly affecting such processes and many areas are experiencing an increasing human pressure on water resources. Therefore, it is crucial to develop reliable methods to quantify the partitioning of rainfall, snow and ice melt contribution to runoff. This study focuses on the identification of the sources of stream runoff in a glacierized catchment in the Eastern Italian Alps by means of isotopic (?18O) and electrical conductivity data. The information is then used for the parameterization of the distributed hydrological model GEOtop 1.2, applied implementing different model scenarios. Field work and modelling activities were carried out for the Saldur basin (South Tyrol, 62 km2 drainage area). Catchment elevations range between 900 and 3700 m a.s.l., and the main glacier is located between 2700 and 3700 m a.s.l. (3.3 km2 glacier extent). Water stage was continuously recorded at two cross sections at 2150 m a.s.l. (20 km2 drainage area) and at 2350 m a.s.l. (11 km2 drainage area). Additionally, discharge measurements (by salt dilution method) were carried out to build up the flow rating curves. From late spring to early fall 2011, two sampling approaches were adopted to measure the spatial and temporal variability of tracer concentration: (1) monthly or twice a month water samples were manually taken in the Saldur stream and in its tributaries at different sections ranging from 1800 m to 2400 m a.s.l., and also in some spring sources considered as possible end-members. (2) hourly water samples over 24 hours were taken simultaneously at different stream sections, tributaries and spring sources during two glacier melt- and snowmelt-induced flood events in mid-July and mid-August. Tracer results confirm a great contribution of snow and ice melt to runoff during warmer days, while the influence of groundwater increased during colder days. Isotope data for two daily melting cycles in mid-July and mid-August 2011 highlight different snow and ice melt contributions to river runoff, reflecting the reduced extent of snow cover in the basin during the later period. Based on this information, for both sub-catchments, GEOtop model was run. Input data contained a digital elevation model, land cover data, and the current glacier extent. Meteorological data was provided by a weather station managed by the European Academy of Bozen/Bolzano (EURAC). In order to isolate the contribution of snow- versus ice-related runoff, model scenarios were prepared with different initial model conditions (i.e. snow cover and ice cover extent). Model results thus provided an independent estimation of the different water sources and offered a conceptual framework for isotopic observations.

Engel, M.; Bertoldi, G.; Penna, D.; Comiti, F.

2012-04-01

304

Estimation of groundwater contribution in runoff from small agricultural dominated catchments  

NASA Astrophysics Data System (ADS)

Under poor natural drainage condition, agricultural land has to be provided with subsurface drainage systems to discharge excess water from the rootzone, thereby guaranteeing optimal cropping conditions during the growing season, while in addition facilitating land preparation. Subsurface drainage systems can significantly contribute in runoff and nutrient loss generation. A secondary effect of drainage systems is that it reduces surface runoff and thereby erosion and phosphorus loss. In addition to surface and subsurface runoff, a third component, being groundwater, is contributing in runoff. As only information about the total runoff at the catchment outlet is available, uncertainty exists about the contribution of the different flow processes. Agriculture is a main contributor of nutrients and sediments to surface water causing water quality problems. Knowledge about the different pathways of water and hence nutrients and sediments to open water systems is important with respect to the choice of mitigation measures in agricultural dominated catchments. Estimates of groundwater or baseflow contribution (BFI) are often based on the use of digital filters applied to average daily discharge values. When using recommended values for the digital filter, this resulted in BFI of 40 - 50 % when applied to small Norwegian agricultural catchments. When taking the poor natural drainage conditions into consideration in addition to the presence of heavy marine clay deposits at depths greater than 1 - 2 m below soil surface, these values are considered unrealistically high. Deelstra et al (2010) showed that small agricultural catchments can have rather "flashy" runoff behaviour, characterised by large diurnal variations in discharge which also contradicts high baseflow contributions. An approach to obtain a realistic filter parameter for a digital filter has been carried out, based on discharge measurements on a set of small, nested catchments in Norway and further tested in Latvia. Each set consisted of a field providing both surface and subsurface runoff located within the catchment. Different filters were tested but the one developed by Chapman & Maxwell (1996) was selected. An improved filter parameter value was obtained, resulting in more realistic values for BFI in Norwegian catchments, being in the order of 10%. The values for the Latvian catchments were slightly higher, the main reason for this being soil types and geological settings. The results indicate that care should be taken in selecting the digital filter value for catchments having flashy runoff behaviour. This might lead to wrong estimates of baseflow contribution which can have negative effects on modelling hydrology, pollutant transport and the selection of mitigation measures at the scale of small agricultural catchments. References Chapman, T.G., Maxwell, A.I . 1996. Baseflow separation - comparison of numerical methods with tracer experiments. Institute Engineers Australia National Conference. Publ. 96/05, 539-545 Deelstra, J., Eggestad, H.O., Iital, A., Jansons, V. and Barkved, L.J. (2010), "Time resolution and hydrological characteristics in agricultural catchments", in Hermann, A. and Schumann, S. (Eds), Status and Perspectives of Hydrology in Small Basins, Vol. 336, IAHS Publication, pp. 138 - 143.

Deelstra, Johannes; Jansons, Viesturs; Lagzdi?š, Ainis

2013-04-01

305

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

NASA Astrophysics Data System (ADS)

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. Second order sensitivities indicate that although parameter interactions are a ubiquitous characteristic of CRR models, their influence varies depending on specific model structure. Combining first and higher order sensitivity indices can mask trends in the results for a parameter when first order components behave in a different manner to higher-order components, thereby preventing meaningful correlations with catchment characteristics. This was the case for overland flow parameters in two of the models, where the total sensitivity for a parameter masked the strong but opposite trends of the first and second order sensitivities. Model sensitivity to the internal pathways are not reflected in the performance criteria results, emphasising that flow path contributions must be constrained by independent data to ensure results within realistic bounds. Parameter identification remains a fundamental challenge. Understanding and limiting parameter interactions in model structures are vital steps for successful parameter estimation in ungauged catchments. Results of parameter sensitivities evaluated by internal flow path partitioning highlight that when an appropriate CRR model is selected, it is a useful tool for investigating the distribution of flows from hydrological pathways to total stream flow at catchment scale.

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

2013-12-01

306

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

PubMed

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. PMID:22204938

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

2012-12-15

307

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...

308

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

PubMed

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. PMID:25228091

Hughes, Andrew O; Quinn, John M

2014-12-01

309

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

NASA Astrophysics Data System (ADS)

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.

Hughes, Andrew O.; Quinn, John M.

2014-12-01

310

The Humber catchment and its coastal area: from UK to European perspectives.  

PubMed

The present water quality of the Humber rivers and coastal zone depends on a complex interplay of factors, including physical ones, such as the underlying geology, which influences soil type, climatic ones, such as the rainfall, which influences runoff, socio-economic ones, which influence present-day human activities in the catchment, and the legacy of former activities, such as contaminated sediments from mining. All of these factors affect the fluxes of nutrients and other contaminants to the rivers and coastal zone. The Water Framework Directive (WFD) requires the production of a river basin management plan intended to lead to the achievement of good chemical and ecological status for all water bodies in the catchment over the next two decades. This paper provides an overview of the current environmental and socio-economic state of the Humber catchment and coastal zone, and broadly examines how socio-economic drivers affect the fluxes of nutrients and contaminants to the coastal zone, using the driver-pressure-state-impact-response (DPSIR) approach. This is followed by an overview of future research, describing the use of scenarios to simulate future fluxes and provide a consistent framework to evaluate potential policies to improve water quality in the estuary. The Humber catchment is one of eight case studies within a European research project, EUROCAT (EVK1-CT-2000-00044), which aims to achieve integrated catchment and coastal zone management by analysing the response of the coastal sea to changes in fluxes of nutrients and contaminants from the catchments. For the Humber case study, the research focuses on the fluxes of two nutrient elements, N and P, and four metal contaminants, As, Cu, Pb and Zn. The project requires the integration of scientific and socio-economic approaches, bringing together quantitative environmental data garnered for individual river catchments and coastal zones in previous research programmes, and local and regional socio-economic data, to aid decision-makers in their search for integrated and sustainable coastal zone management strategies. PMID:14499525

Cave, R R; Ledoux, L; Turner, K; Jickells, T; Andrews, J E; Davies, H

2003-10-01

311

Modelling remediation scenarios in historical mining catchments.  

PubMed

Local remediation measures, particularly those undertaken in historical mining areas, can often be ineffective or even deleterious because erosion and sedimentation processes operate at spatial scales beyond those typically used in point-source remediation. Based on realistic simulations of a hybrid landscape evolution model combined with stochastic rainfall generation, we demonstrate that similar remediation strategies may result in differing effects across three contrasting European catchments depending on their topographic and hydrologic regimes. Based on these results, we propose a conceptual model of catchment-scale remediation effectiveness based on three basic catchment characteristics: the degree of contaminant source coupling, the ratio of contaminated to non-contaminated sediment delivery, and the frequency of sediment transport events. PMID:24197965

Gamarra, Javier G P; Brewer, Paul A; Macklin, Mark G; Martin, Katherine

2014-06-01

312

Identification of internal flow dynamics in two experimental catchments  

USGS Publications Warehouse

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.

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

1997-01-01

313

Snow cover trend and hydrological characteristics of the Astore River basin (Western Himalayas) and its comparison to the Hunza basin (Karakoram region).  

PubMed

A large proportion of Pakistan's irrigation water supply is taken from the Upper Indus River Basin (UIB) in the Himalaya-Karakoram-Hindukush range. More than half of the annual flow in the UIB is contributed by five of its snow and glacier-fed sub-basins including the Astore (Western Himalaya - south latitude of the UIB) and Hunza (Central Karakoram - north latitude of the UIB) River basins. Studying the snow cover, its spatio-temporal change and the hydrological response of these sub-basins is important so as to better manage water resources. This paper compares new data from the Astore River basin (mean catchment elevation, 4100 m above sea level; m asl afterwards), obtained using MODIS satellite snow cover images, with data from a previously-studied high-altitude basin, the Hunza (mean catchment elevation, 4650 m asl). The hydrological regime of this sub-catchment was analyzed using the hydrological and climate data available at different altitudes from the basin area. The results suggest that the UIB is a region undergoing a stable or slightly increasing trend of snow cover in the southern (Western Himalayas) and northern (Central Karakoram) parts. Discharge from the UIB is a combination of snow and glacier melt with rainfall-runoff at southern part, but snow and glacier melt are dominant at the northern part of the catchment. Similar snow cover trends (stable or slightly increasing) but different river flow trends (increasing in Astore and decreasing in Hunza) suggest a sub-catchment level study of the UIB to understand thoroughly its hydrological behavior for better flood forecasting and water resources management. PMID:25461078

Tahir, Adnan Ahmad; Chevallier, Pierre; Arnaud, Yves; Ashraf, Muhammad; Bhatti, Muhammad Tousif

2015-02-01

314

Comparison of catchment and network delineation approaches in complex suburban environments. Application to the Chaudanne catchment, France.  

E-print Network

other automatic catchment delineation methods based on stream burning, flow direction forcing the catchment response (Zheng and Baetz, 1999). They also raise overland flow causing erosion problems (Jones et

Paris-Sud XI, Université de

315

Modeling daily streamflow at ungauged catchments: What information is necessary?  

NASA Astrophysics Data System (ADS)

Streamflow modeling at ungauged catchments involves transfer of information (viz., model structure and parameters) from gauged to ungauged catchments that are judged to be hydrologically similar. In this study, we focus on identifying: (1) what constitutes the critical information that needs to be transferred among hydrologically similar catchments to achieve good predictability using models at ungauged sites, and (2) which is the best approach for transferring this information from gauged to ungauged catchments. We develop a simple hydrologic model with minimal calibration requirement and implement it over 756 catchments located across the continental United States. The model computes water balance at a daily time-step and conceptualizes subsurface runoff through a storage-dependent exponential decline in saturated hydraulic conductivity. Snow accumulation and melt are modeled using the thermal degree-day concept. The calibrated model performs better in humid runoff-dominated regions than in the drier evapotranspiration-dominated regions. Results show that within a region, transfer of hydrograph recession information alone is sufficient for reliable streamflow predictions at ungauged catchments. Information transfer from spatially proximate gauged catchments provides better streamflow predictability at ungauged catchments than transfer from catchments identified as physically similar. When considering spatially proximate catchments, information transfer from multiple donor catchments is preferable to transfer from a single donor catchment.

Patil, S.; Stieglitz, M.

2011-12-01

316

Differing chemical weathering conditions in meltwater catchments of western Greenland  

NASA Astrophysics Data System (ADS)

Chemical weathering in the proglacial environment is limited by moisture availability rather than by temperature and proceeds at rates comparable to more temperate catchments of similar specific discharge. Moisture originates from two sources during the ablation season in proglacial environments: snow melt from non-glacierized catchments and directly from glacial melt. The magnitudes of these water sources create differences in stream size and ecology, which may result in different styles and rates of weathering due to differences in water rock interaction time and acid sources. We test this hypothesis through observations of specific conductance (SpC) and stable isotopes of water collected from streams in the Paakitsoq region of western Greenland in July 2011. In the Paakitsoq region, snow and glacier melt waters flow through distinct drainage basins with different types and amounts of vegetation. Basins that only receive water from snow melt have small clear streams that flow through vegetated marshlands. In contrast, basins where the greatest water flux is derived from glacial melt host larger turbid streams that drain across frontal moraines and continue along largely unvegetated flow paths. Snow and glacier end members can be separated by stable isotopic compositions (snow: ?D: -107.3 %; ?18O: -14.8 % and glacier: ?D: -229.8 %; ?18O: -29.7 %). Water isotopes from the two types of streams fall between the snow and glacier end member compositions, reflecting addition of snow melt to the turbid streams and isotopic fractionation of the snow as it melts. Isotopic compositions of water in the turbid streams lie along the global meteoric water line (GMWL), but isotopic compositions from the clear streams lie to the left of the GMWL and reflect preferential weathering in the more highly vegetated watersheds. The greatest amount of chemical weathering occurs in flat, marshy areas in the clear stream catchments, presumably as a result of decreased pH caused by plant metabolism and/or microbial reactions, lower specific discharge, and longer residence times. Higher chemical weathering rates in the clear streams are supported by field measurements of SpC that increase downstream from the snow source. SpC of turbid streams are lower than clear streams but increase downstream as they discharge to a single braided, turbid channel that flows ~20 km to the ocean. Future work on these samples will include analyses of major and trace elements, inorganic and organic carbon species, and Sr and Nd isotopes of water and compositions of rock, suspended and bedload sediments. These measurements will aid in understanding which phases contribute the most weathering products to the water and how these products interact with the local ecosystem, as well as quantify the delivery of weathering products to the ocean. Our results reflect the control of ecology on weathering in high latitude areas. This linkage of weathering to ecology suggests that weathering rates and magnitudes will vary with time through the ablation season depending on melt rate, residence time of water in the stream channels and ecosystems, and magnitude of primary productivity.

Deuerling, K. M.; Martin, J. B.; Gulley, J.

2011-12-01

317

Comparative assessment of predictions in ungauged basins - Part 2: Flood and low flow studies  

NASA Astrophysics Data System (ADS)

The objective of this paper is to assess the performance of methods that predict low flows and flood runoff in ungauged catchments. The aim is to learn from the similarities and differences between catchments in different places, and to interpret the differences in performance in terms of the underlying climate-landscape controls. The assessment is performed at two levels. The Level 1 assessment is a meta-analysis of 14 low flow prediction studies reported in the literature involving 3112 catchments, and 20 flood prediction studies involving 3023 catchments. The Level 2 assessment consists of a more focused and detailed analysis of individual basins from selected studies from Level 1 in terms of how the leave-one-out cross-validation performance depends on climate and catchment characteristics as well as on the regionalisation method. The results indicate that both flood and low flow predictions in ungauged catchments tend to be less accurate in arid than in humid climates and more accurate in large than in small catchments. There is also a tendency towards a somewhat lower performance of regressions than other methods in those studies that apply different methods in the same region, while geostatistical methods tend to perform better than other methods. Of the various flood regionalisation approaches, index methods show significantly lower performances in arid catchments than regression methods or geostatistical methods. For low flow regionalisation, regional regressions are generally better than global regressions.

Salinas, J. L.; Laaha, G.; Rogger, M.; Parajka, J.; Viglione, A.; Sivapalan, M.; Blöschl, G.

2013-01-01

318

Floods and low flows prediction in ungauged basins - a comparative assessment of studies  

NASA Astrophysics Data System (ADS)

The objective of this study is to assess the performance of methods that predict low flows and flood runoff in ungauged catchments. The aim is to learn from the similarities and differences between catchments in different places, and to interpret the differences in performance in terms of the underlying climate-landscape controls. The assessment is performed at two levels. The Level 1 assessment is a meta-analysis of 14 low flow prediction studies reported in the literature involving 3112 catchments, and 20 flood prediction studies involving 3023 catchments. The Level 2 assessment consists of a more focused and detailed analysis of individual basins from selected studies from Level 1 in terms of how the leave-one-out cross-validation performance depends on climate and catchment characteristics as well as on the regionalisation method. The results indicate that both flood and low flow predictions in ungauged catchments tend to be less accurate in arid than in humid climates and more accurate in large than in small catchments. There is also a tendency towards a somewhat lower performance of regressions than other methods in those studies that apply different methods in the same region, while geostatistical methods tend to perform better than other methods. Of the various flood regionalisation approaches, index methods show significantly lower performances in arid catchments than regression methods or geostatistical methods. For low flow regionalisation, regional regressions are generally better than global regressions.

Salinas, Jose Luis; Laaha, Gregor; Rogger, Magdalena; Parajka, Juraj; Viglione, Alberto; Sivapalan, Murugesu; Bloeschl, Guenter

2013-04-01

319

Comparative assessment of predictions in ungauged basins - Part 2: Flood and low flow studies  

NASA Astrophysics Data System (ADS)

The objective of this paper is to assess the performance of methods that predict low flows and flood runoff in ungauged catchments. The aim is to learn from the similarities and differences between catchments in different places, and to interpret the differences in performance in terms of the underlying climate-landscape controls. The assessment is performed at two levels. The Level 1 assessment is a meta-analysis of 14 low flow prediction studies reported in the literature involving 3112 catchments, and 20 flood prediction studies involving 3023 catchments. The Level 2 assessment consists of a more focused and detailed analysis of individual basins from selected studies from Level 1 in terms of how the leave-one-out cross-validation performance depends on climate and catchment characteristics as well as on the regionalisation method. The results indicate that both flood and low flow predictions in ungauged catchments tend to be less accurate in arid than in humid climates and more accurate in large than in small catchments. There is also a tendency towards a somewhat lower performance of regressions than other methods in those studies that apply different methods in the same region, while geostatistical methods tend to perform better than other methods. Of the various flood regionalisation approaches, index methods show significantly lower performance in arid catchments than regression methods or geostatistical methods. For low flow regionalisation, regional regressions are generally better than global regressions.

Salinas, J. L.; Laaha, G.; Rogger, M.; Parajka, J.; Viglione, A.; Sivapalan, M.; Blöschl, G.

2013-07-01

320

Comparative assessment of predictions in ungauged basins - Part 1: Runoff hydrograph studies  

NASA Astrophysics Data System (ADS)

The objective of this assessment is to compare studies predicting runoff hydrographs in ungauged catchments. The aim is to learn from the differences and similarities between catchments in different locations, and to interpret the differences in performance in terms of the underlying climate and landscape controls. The assessment is performed at two levels. The Level 1 assessment is a meta-analysis of 34 studies reported in the literature involving 3874 catchments. The Level 2 assessment consists of a more focused and detailed analysis of individual basins from selected studies from Level 1 in terms of how the leave-one-out cross-validation performance depends on climate and catchment characteristics as well as on the chosen regionalisation method. The results indicate that runoff hydrograph predictions in ungauged catchments tend to be more accurate in humid than in arid catchments and more accurate in large than in small catchments. The dependence of performance on elevation differs by regions and depends on how aridity varies with elevation and air temperature. The effect of parameter regionalisation method on model performance differs between studies. However, there is a tendency towards a somewhat lower performance of regressions than other methods in those studies that apply different methods in the same region. In humid catchments spatial proximity and similarity methods perform best while in arid catchments similarity and parameter regression methods perform slightly better. For studies with a large number of catchments (dense stream gauge network) there is a tendency for spatial proximity and geostatistics to perform better than regression or regionalisation based on simple averaging of model parameters from gauged catchments. There was no clear relationship between predictive performance and the number of regionalised model parameters. The implications of the findings are discussed in the context of model building.

Parajka, J.; Viglione, A.; Rogger, M.; Salinas, J. L.; Sivapalan, M.; Blöschl, G.

2013-01-01

321

Comparative assessment of predictions in ungauged basins - Part 1: Runoff-hydrograph studies  

NASA Astrophysics Data System (ADS)

The objective of this assessment is to compare studies predicting runoff hydrographs in ungauged catchments. The aim is to learn from the differences and similarities between catchments in different locations, and to interpret the differences in performance in terms of the underlying climate and landscape controls. The assessment is performed at two levels. The Level 1 assessment is a meta-analysis of 34 studies reported in the literature involving 3874 catchments. The Level 2 assessment consists of a more focused and detailed analysis of individual basins from selected studies from Level 1 in terms of how the leave-one-out cross-validation performance depends on climate and catchment characteristics as well as on the chosen regionalisation method. The results indicate that runoff-hydrograph predictions in ungauged catchments tend to be more accurate in humid than in arid catchments and more accurate in large than in small catchments. The dependence of performance on elevation differs by regions and depends on how aridity varies with elevation and air temperature. The effect of the parameter regionalisation method on model performance differs between studies. However, there is a tendency towards a somewhat lower performance of regressions than other methods in those studies that apply different methods in the same region. In humid catchments spatial proximity and similarity methods perform best while in arid catchments similarity and parameter regression methods perform slightly better. For studies with a large number of catchments (dense stream gauge network) there is a tendency for spatial proximity and geostatistics to perform better than regression or regionalisation based on simple averaging of model parameters from gauged catchments. There was no clear relationship between predictive performance and the number of regionalised model parameters. The implications of the findings are discussed in the context of model building.

Parajka, J.; Viglione, A.; Rogger, M.; Salinas, J. L.; Sivapalan, M.; Blöschl, G.

2013-05-01

322

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

USGS Publications Warehouse

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 South Atlantic-Gulf and Tennessee River basins, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

323

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

USGS Publications Warehouse

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, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

324

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

USGS Publications Warehouse

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 NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

325

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

USGS Publications Warehouse

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 Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

326

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

USGS Publications Warehouse

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, Upper Mississippi, and Souris-Red-Rainy River basins, contains NHDPlus Production Units 4, 5, 7 and 9. MRB4, covering the Missouri River basins, contains NHDPlus Production Units 10-lower and 10-upper. MRB5, covering the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf River basins, contains NHDPlus Production Units 8, 11 and 12. MRB6, covering the Rio Grande, Colorado and Great Basin River basins, contains NHDPlus Production Units 13, 14, 15 and 16. MRB7, covering the Pacific Northwest River basins, contains NHDPlus Production Unit 17. MRB8, covering California River basins, contains NHDPlus Production Unit 18.

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

327