NASA Astrophysics Data System (ADS)
Seok, Song Young; Ho, Song Yang; Ho, Lee Jung; Moo Jong, Park
2015-04-01
Due to the increase of impervious layers caused by increased rainfall and urbanization which were brought about by the climate change after the late 1990s, the flood damage in urban watersheds is rising. The recent flood damage is occurring in medium and small stream rather than in large stream. Particularly, in medium stream which pass the cities, sudden flood occurs due to the short concentration of rainfall and urban areas suffer large damage, even though the flood damage is small, since residential areas and social infrastructures are concentrated. In spite of the importance of medium and small stream to pass the cities, there is no certain standard for classification of natural or urban stream and existing studies are mostly focused on the impervious area among the land use characteristics of watersheds. Most of existing river studies are based on the watershed scale, but in most urban watersheds where stream pass, urban areas are concentrated in the confluence, so urban areas only occupy less than 10% of the whole watershed and there is a high uncertainty in the classification of urban areas, based the watershed of stream. This study aims to suggest a classification standard of medium and small stream between local stream and small stream where suffer flood damage. According to the classified medium and small stream, this study analyzed the stream area to the stream width and distance using Arcgis Buffer tool, based on the stream line, not the existing watershed scale. This study then chose urban watersheds by analyzing the river area at certain intervals from the center of the chosen medium and small stream, in different ways. Among the land use characteristics in urban areas, the impervious area was applied to the selection standard of urban watersheds and the characteristics of urban watersheds were presented by calculating the ratio of the stream area to the impervious area using the Buffer tool. Acknowledgement "This research was supported by a grant [NEMA-NH-2011-45] from the Natural Hazard Mitigation Research Group, National Emergency Management Agency of Korea." Keywords: land use, urban watershed, medium and smaill stream, impervious area
Terziotti, Silvia; McMahon, Gerard; Bell, Amanda H.
2012-01-01
As part of the U.S. Geological Survey National Water-Quality Assessment Program, the effects of urbanization on stream ecosystems (EUSE) have been intensively investigated in nine metropolitan areas in the United States, including Boston, Massachusetts; Atlanta, Georgia; Birmingham, Alabama; Raleigh, North Carolina; Salt Lake City, Utah; Denver, Colorado; Dallas–Fort Worth, Texas; Portland, Oregon; and Milwaukee–Green Bay, Wisconsin. Each of the EUSE study area watersheds was associated with one ecological region of the United States. This report evaluates whether each metropolitan area can be generalized across the ecological regions (ecoregions) within which the EUSE study watersheds are located. Seven characteristics of the EUSE watersheds that affect stream ecosystems were examined to determine the similarities in the same seven characteristics of the watersheds in the entire ecoregion. Land cover (percentage developed, forest and shrubland, and herbaceous and cultivated classes), average annual temperature, average annual precipitation, average surface elevation, and average percentage slope were selected as human-influenced, climate, and topography characteristics. Three findings emerged from this comparison that have implications for the use of EUSE data in models used to predict stream ecosystem condition. One is that the predominant or "background" land-cover type (either forested or agricultural land) in each ecoregion also is the predominant land-cover type within the associated EUSE study watersheds. The second finding is that in all EUSE study areas, the watersheds account for the range of developed land conditions that exist in the corresponding ecoregion watersheds. However, six of the nine EUSE study area watersheds have significantly different distributions of developed land from the ecoregion watersheds. Finally, in seven of the nine EUSE/ecoregion comparisons, the distributions of the values of climate variables in the EUSE watersheds are different from the distributions for watersheds in the corresponding ecoregions.
THE ROLE OF WATERSHED CLASSIFICATION IN DIAGNOSING CAUSES OF BIOLOGICAL IMPAIRMENT
We compared classification schemes based on watershed storage (wetland + lake area/watershed area) and forest fragmention with a gewographically-based classification scheme for two case studies involving 1) Lake Superior tributaries and 2) watersheds of riverine coastal wetlands ...
NASA Astrophysics Data System (ADS)
Arulbalaji, P.; Gurugnanam, B.
2017-11-01
A morphometric analysis of Sarabanga watershed in Salem district has been chosen for the present study. Geospatial tools, such as remote sensing and GIS, are utilized for the extraction of river basin and its drainage networks. The Shuttle Radar Topographic Mission (SRTM-30 m resolution) data have been used for morphometric analysis and evaluating various morphometric parameters. The morphometric parameters of Sarabanga watershed have been analyzed and evaluated by pioneer methods, such as Horton and Strahler. The dendritic type of drainage pattern is draining the Sarabanga watershed, which indicates that lithology and gentle slope category is controlling the study area. The Sarabanga watershed is covered an area of 1208 km2. The slope of the watershed is various from 10 to 40% and which is controlled by lithology of the watershed. The bifurcation ratio ranges from 3 to 4.66 indicating the influence of geological structure and suffered more structural disturbances. The form factor indicates elongated shape of the study area. The total stream length and area of watershed indicate that mean annual rainfall runoff is relatively moderate. The basin relief expressed that watershed has relatively high denudation rates. The drainage density of the watershed is low indicating that infiltration is more dominant. The ruggedness number shows the peak discharges that are likely to be relatively higher. The present study is very useful to plan the watershed management.
We compared classification schemes based on watershed storage (wetland + lake area/watershed area) and forest fragmentation with a geographically-based classification scheme for two case studies involving 1) Lake Superior tributaries and 2) watersheds of riverine coastal wetlands...
We compared classification schemes based on watershed storage (wetland + lake area/watershed area) and forest fragmentation with a geographically-based classification scheme for two case studies involving 1)Lake Superior tributaries and 2) watersheds of riverine coastal wetlands ...
Studying Watersheds: A Confluence of Important Ideas. ERIC Digest.
ERIC Educational Resources Information Center
Haury, David L.
This digest explains how the study of watersheds can serve to connect concept and skill development across subject areas and grade levels for curriculum reform and standards-based assessment. Specific resources are organized into watersheds in the curriculum, connections to National Standards, watershed concepts and activities, watershed education…
NASA Astrophysics Data System (ADS)
Stednick, J. D.; Ice, G. G.; Hale, V. C.
2006-12-01
The original Alsea Watershed Study (1959-1973) was a paired study in the Oregon Coast Range designed to assess the physical and biological effects of timber harvesting on water and salmonid resources. The 3 streams chosen for study, Deer Creek, Flynn Creek, and Needle Branch, are tributaries of Drift Creek, which flows into Alsea Bay. The watersheds lie about 16 km from the Pacific Ocean, and have a maritime climate, with mean annual precipitation approximately 250 cm, almost all of which falls as rain from October through March. Flynn Creek served as an undisturbed control watershed, Deer Creek had 3 patch cuts (25% of the watershed area) with a streamside vegetation buffer, and Needle Branch was clearcut (85%) with no streamside buffer. The results of the original Alsea Study showed an increase in annual water yield and 3-day peak flows for Needle Branch, and no significant change for any streamflow metric (annual yield, peak flow, or low flows) on Deer Creek. Because the watersheds "generally appear to be returning to pre-logging conditions" the authors of the original study believed hydrologic recovery had occurred. The streamflow gauging network was reestablished in 1990 as the New Alsea Watershed Study. Additional streamflow monitoring (1990-1996) suggested that the watersheds deemed to be "recovered" still showed departures from the pre-treatment relations. Streamflow monitoring from the same period suggested 24 years for vegetation regrowth to return to hydrologic functions similar to the pretreatment. A literature review of paired watershed studies suggested that in the Pacific Northwest at least 25% of the watershed area needed to be harvested to be detectable with streamflow monitoring. Flynn Creek was designated a long-term Research Natural Area by the USDA Forest Service in 1976, and remains an undisturbed temperate coniferous forested watershed. Deer Creek had a second timber harvesting entry in 1978 of 20 ha and two units of 14.5 and 8.4 ha were logged in 1987 and 1988. Approximately 39% of the watershed has now been harvested. Since the original study, forest management on Needle Branch has included precommercial and commercial thinning. Approximately 25% of the middle third of the watershed was precommercially thinned in 1981. In 1997-1998 approximately 40% of this area was commercially thinned with a 30% basal area removal. With 15 years of additional streamflow data, are the 25% basal area removal and 24 year hydrologic recovery axioms true for the Alsea study watersheds?
Stanislaw J. Tajchman; Hailiang Fu; James N. Kochenderfer; Pan Chunshen
1995-01-01
Spatial variation of topography, net radiation, evapotranspiration, and forest stand in the central Appalachian watershed is described. The study area is the control watershed 4 (39"20'N, 79"49"W) located in the Fernow Experimental Forest at Parsons, West Virginia. The watershed encompasses an area of 39.2 ha, it has a southeast orientation, and the...
NASA Astrophysics Data System (ADS)
Amri, Khairul; Nugraha, Loparedo; Barchia, Muhammad Faiz
2017-11-01
Land use changes in Manna watershed are caused degradation in the watershed functions. When water infiltration goes down, some water runs off flowing to Manna River cause submerged on the downstream. The aim of this study is to analyze how the Manna watershed overcoming environmentally degraded conditions. The critical level of the Manna catchment areas was determined by overlaying some digital maps based on procedure applying in the Ministry of Forestry, Republic of Indonesia (P.32/MENHUT-II/2009). Measuring the critical level of the catchment also needed natural and actual infiltrations map, and the interpretation process of the analysis used ArcGIS 10.1 software. Based on the spatial data analysis by overlaying maps of slope, soils, and rainfall, the natural infiltration rate in the Manna watershed categorized high level (44.1%). While, the critical level of the catchment areas of the Manna watershed classified in good condition cover about 64,5 % of the areas, and starting to degraded state cover about 35,5 % of the watershed areas. The environment degradation conditions indicated the land use changes in the Manna watershed could deteriorate infiltration rates. The cultivated agricultural activities neglected conservation rule could accelerate the critical catchment areas in the Manna watershed.
Lopez, M.A.; Woodham, W.M.
1983-01-01
Hydrologic data collected on nine small urban watersheds in the Tampa Bay area of west-central Florida and a method for estimating peak discharges in the study area are described. The watersheds have mixed land use and range in size from 0.34 to 3.45 square miles. Watershed soils, land use, and storm-drainage system data are described. Urban development ranged from a sparsely populated area with open-ditch storm sewers and 19% impervious area to a completely sewered watershed with 61% impervious cover. The U.S. Geological Survey natural-basin and urban-watershed models were calibrated for the nine watersheds using 5-minute interval rainfall data from the Tampa, Florida, National Weather Service rain gage to simulate annual peak discharge for the period 1906-52. A log-Pearson Type III frequency analysis of the simulated annual maximum discharge was used to determine the 2-, 5-, 10-, 25-, 50-, and 100-year flood discharges for each watershed. Flood discharges were related in a multiple-linear regression to drainage area, channel slope, detention storage area, and an urban-development factor determined by the extent of curb and gutter street drainage and storm-sewer system. The average standard error for the regional relations ranged from + or - 32 to + or - 42%. (USGS)
Shao, Ya; Cai, Chongfa; Zhang, Haitao; Fu, Wei; Zhong, Xuemei; Tang, Shen
2018-05-10
Selenium (Se) is an essential nutritional element for human beings. Many studies have been conducted on concentration and distribution patterns of soil Se in low Se, Se-enriched, and selenosis areas; however, soil Se has not been systematically studied in a watershed, especially in Se-enriched longevity region and karst area in South China. This study is carried out to explore the controlling factors of Se-enriched soils in Baishou river tributary watershed, where soils are Se-enriched, and local people have the phenomenon of longevity. The area-weighted average rock Se concentration in the watershed is 0.054 mg/kg, and there are no significant differences in rock Se concentration between different strata and between different lithological rocks. The area-weighted average concentration of Se in soils (0-20 cm) is 0.80 mg/kg, and the soil Se concentration is of high level in the watershed. Soil Se concentration decreases from upstream to downstream in the watershed, and significantly correlated with elevation. Climate is the main factor causing high content of soil Se in the watershed which lacks black rock series. The difference of clastic and carbonate parent materials in soil forming process and the physical and chemical properties (pH, OM, etc.) are the main reasons for the spatial variation of Se distribution in the watershed. The research will be beneficial to the development and utilization of Se-enriched soil in Se-enriched area.
Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping
2017-11-03
Considerable growth in the economy and population of the Dongting Lake watershed in Southern China has increased phosphorus loading to the lake and resulted in a growing risk of lake eutrophication. This study aimed to reveal the spatial pattern and sources of phosphorus export and loading from the watershed. We applied an export coefficient model and the Dillon-Rigler model to quantify contributions of different sub-watersheds and sources to the total phosphorus (TP) export and loading in 2010. Together, the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area contributed 60.9% of the TP exported from the entire watershed. Livestock husbandry appeared to be the largest anthropogenic source of TP, contributing more than 50% of the TP exported from each secondary sub-watersheds. The actual TP loading to the lake in 2010 was 62.9% more than the permissible annual TP loading for compliance with the Class III water quality standard for lakes. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-contributed 91.2% of the total TP loading. As the largest contributor among all sources, livestock husbandry contributed nearly 50% of the TP loading from the Dongting Lake Area and more than 60% from each of the other primary sub-watersheds. This study provides a methodology to identify the key sources and locations of TP export and loading in large lake watersheds. The study can provide a reference for the decision-making for controlling P pollution in the Dongting Lake watershed.
NASA Astrophysics Data System (ADS)
Chen, Y.
2017-12-01
Urbanization is the world development trend for the past century, and the developing countries have been experiencing much rapider urbanization in the past decades. Urbanization brings many benefits to human beings, but also causes negative impacts, such as increasing flood risk. Impact of urbanization on flood response has long been observed, but quantitatively studying this effect still faces great challenges. For example, setting up an appropriate hydrological model representing the changed flood responses and determining accurate model parameters are very difficult in the urbanized or urbanizing watershed. In the Pearl River Delta area, rapidest urbanization has been observed in China for the past decades, and dozens of highly urbanized watersheds have been appeared. In this study, a physically based distributed watershed hydrological model, the Liuxihe model is employed and revised to simulate the hydrological processes of the highly urbanized watershed flood in the Pearl River Delta area. A virtual soil type is then defined in the terrain properties dataset, and its runoff production and routing algorithms are added to the Liuxihe model. Based on a parameter sensitive analysis, the key hydrological processes of a highly urbanized watershed is proposed, that provides insight into the hydrological processes and for parameter optimization. Based on the above analysis, the model is set up in the Songmushan watershed where there is hydrological data observation. A model parameter optimization and updating strategy is proposed based on the remotely sensed LUC types, which optimizes model parameters with PSO algorithm and updates them based on the changed LUC types. The model parameters in Songmushan watershed are regionalized at the Pearl River Delta area watersheds based on the LUC types of the other watersheds. A dozen watersheds in the highly urbanized area of Dongguan City in the Pearl River Delta area were studied for the flood response changes due to urbanization, and the results show urbanization has big impact on the watershed flood responses. The peak flow increased a few times after urbanization which is much higher than previous reports.
Lin, Chen; Ma, Ronghua; He, Bin
2015-12-24
Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r² was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality.
Lin, Chen; Ma, Ronghua; He, Bin
2015-01-01
Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r2 was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality. PMID:26712772
Runoff potentiality of a watershed through SCS and functional data analysis technique.
Adham, M I; Shirazi, S M; Othman, F; Rahman, S; Yusop, Z; Ismail, Z
2014-01-01
Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling.
Runoff Potentiality of a Watershed through SCS and Functional Data Analysis Technique
Adham, M. I.; Shirazi, S. M.; Othman, F.; Rahman, S.; Yusop, Z.; Ismail, Z.
2014-01-01
Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling. PMID:25152911
Hou, Ying; Li, Bo; Müller, Felix; Chen, Weiping
2016-11-01
Watersheds provide multiple ecosystem services. Ecosystem service assessment is a promising approach to investigate human-environment interaction at the watershed scale. The spatial characteristics of ecosystem services are closely related to land use statuses in human-dominated watersheds. This study aims to investigate the effects of land use on the spatial variations of ecosystem services at the Dianchi Lake watershed in Southwest China. We investigated the spatial variations of six ecosystem services-food supply, net primary productivity (NPP), habitat quality, evapotranspiration, water yield, and nitrogen retention. These services were selected based on their significance at the Dianchi Lake watershed and the availability of their data. The quantification of these services was based on modeling, value transference, and spatial analysis in combination with biophysical and socioeconomic data. Furthermore, we calculated the values of ecosystem services provided by different land use types and quantified the correlations between ecosystem service values and land use area proportions. The results show considerable spatial variations in the six ecosystem services associated with land use influences in the Dianchi Lake watershed. The cropland and forest land use types had predominantly positive influences on food productivity and NPP, respectively. The rural residential area and forest land use types reduced and enhanced habitat quality, respectively; these influences were identical to those of evapotranspiration. Urban area and rural residential area exerted significantly positive influences on water yield. In contrast, water yield was negatively correlated with forest area proportion. Finally, cropland and forest had significantly positive and negative influences, respectively, on nitrogen retention. Our study emphasizes the importance of consideration of the influences from land use composition and distribution on ecosystem services for managing the ecosystems of human-dominated watersheds.
USDA-ARS?s Scientific Manuscript database
One finding of the Conservation Effects Assessment Program (CEAP) watershed studies was that Best Management practices (BMPs) were not always installed where most needed: in many watersheds, only a fraction of BMPs were implemented in the most vulnerable areas. While complex computer simulation mode...
Environmental setting of Maple Creek watershed, Nebraska
Fredrick, Brian S.; Linard, Joshua I.; Carpenter, Jennifer L.
2006-01-01
The Maple Creek watershed covers a 955-square-kilometer area in eastern Nebraska, which is a region dominated by agricultural land use. The Maple Creek watershed is one of seven areas currently included in a nationwide study of the sources, transport, and fate of water and chemicals in agricultural watersheds. This study, known as the topical study of 'Agricultural Chemicals: Sources, Transport, and Fate' is part of the National Water-Quality Assessment Program being conducted by the U.S. Geological Survey. The Program is designed to describe water-quality conditions and trends based on representative surface- and ground-water resources across the Nation. The objective of the Agricultural Chemicals topical study is to investigate the sources, transport, and fate of selected agricultural chemicals in a variety of agriculturally diverse environmental settings. The Maple Creek watershed was selected for the Agricultural Chemicals topical study because its watershed represents the agricultural setting that characterizes eastern Nebraska. This report describes the environmental setting of the Maple Creek watershed in the context of how agricultural practices, including agricultural chemical applications and irrigation methods, interface with natural settings and hydrologic processes. A description of the environmental setting of a subwatershed within the drainage area of Maple Creek is included to improve the understanding of the variability of hydrologic and chemical cycles at two different scales.
Yager, Douglas B.; Johnson, Raymond H.; Rockwell, Barnaby W.; Caine, Jonathan S.; Smith, Kathleen S.
2013-01-01
Hydrothermally altered bedrock in the Silverton mining area, southwest Colorado, USA, contains sulfide minerals that weather to produce acidic and metal-rich leachate that is toxic to aquatic life. This study utilized a geographic information system (GIS) and statistical approach to identify watershed-scale geologic variables in the Silverton area that influence water quality. GIS analysis of mineral maps produced using remote sensing datasets including Landsat Thematic Mapper, advanced spaceborne thermal emission and reflection radiometer, and a hybrid airborne visible infrared imaging spectrometer and field-based product enabled areas of alteration to be quantified. Correlations between water quality signatures determined at watershed outlets, and alteration types intersecting both total watershed areas and GIS-buffered areas along streams were tested using linear regression analysis. Despite remote sensing datasets having varying watershed area coverage due to vegetation cover and differing mineral mapping capabilities, each dataset was useful for delineating acid-generating bedrock. Areas of quartz–sericite–pyrite mapped by AVIRIS have the highest correlations with acidic surface water and elevated iron and aluminum concentrations. Alkalinity was only correlated with area of acid neutralizing, propylitically altered bedrock containing calcite and chlorite mapped by AVIRIS. Total watershed area of acid-generating bedrock is more significantly correlated with acidic and metal-rich surface water when compared with acid-generating bedrock intersected by GIS-buffered areas along streams. This methodology could be useful in assessing the possible effects that alteration type area has in either generating or neutralizing acidity in unmined watersheds and in areas where new mining is planned.
Gender sensitive education in watershed management to support environmental friendly city
NASA Astrophysics Data System (ADS)
Asteria, D.; Budidarmono; Herdiansyah, H.; Ni’mah, N. L.
2018-03-01
This study is about gender-sensitive perspective in watershed management education program as one of capacity building for citizens in watershed management with community-based strategy to support environmental friendly cities and security for women from flood disasters. Involving women and increasing women’s active participation in sustainable watershed management is essential in urban area. In global warming and climate change situations, city management should be integrated between social aspect and environmental planning. This study used mix method (concurrent embedded type, with quantitative as primary method) with research type is descriptive-explanatory. The result of this study is education strategies with gender approaches and affirmative action through emancipation approach and local knowledge from women’s experiences can increase women’s participation. Women’s empowerment efforts need integrated intervention and collaboration from government, NGO, and other stakeholders to optimize women’s role in watershed management for support environmental friendly city. The implication of this study is an educational strategy on watershed conservation with gender perspective to offer social engineering alternatives for decision makers to policy of sustainable watershed management in urban area related to flood mitigation efforts.
Cross-boundary cooperation in a watershed context: the sentiments of private forest landowners.
Rickenbach, Mark G; Reed, A Scott
2002-10-01
Ecosystem management and sustainable forestry on mixed ownership landscapes will require some level of cross-boundary coordination or management. Oregon's experiment with local, voluntary, collaborative forums, called watershed councils, is one mechanism to foster cross-boundary management. Fifty qualitative, in-depth interviews in three study areas were conducted with nonindustrial private forest (NIPF) landowners, watershed council members, and agency employees to learn how and why landowners participate (or not) on watershed councils. Study areas were located in three different areas of the state to reflect different ecological and organizational settings. Our case study identified three themes-stewardship ethic, property rights amid uncertainty, and action orientation-that were most salient among landowners when deciding to participate in their local watershed council. Other factors related to competing opportunities were also identified. Our results relate to the social psychological antecedents to cooperation of perceived consensus, group identity, and legitimacy of authority as well as to applied situations where cross-boundary coordination and management are goals.
Qiu, Zeyuan
2009-11-01
A science-based geographic information system (GIS) approach is presented to target critical source areas in watersheds for conservation buffer placement. Critical source areas are the intersection of hydrologically sensitive areas and pollutant source areas in watersheds. Hydrologically sensitive areas are areas that actively generate runoff in the watershed and are derived using a modified topographic index approach based on variable source area hydrology. Pollutant source areas are the areas in watersheds that are actively and intensively used for such activities as agricultural production. The method is applied to the Neshanic River watershed in Hunterdon County, New Jersey. The capacity of the topographic index in predicting the spatial pattern of runoff generation and the runoff contribution to stream flow in the watershed is evaluated. A simple cost-effectiveness assessment is conducted to compare the conservation buffer placement scenario based on this GIS method to conventional riparian buffer scenarios for placing conservation buffers in agricultural lands in the watershed. The results show that the topographic index reasonably predicts the runoff generation in the watershed. The GIS-based conservation buffer scenario appears to be more cost-effective than the conventional riparian buffer scenarios.
Sadeghi, Seyed Hamidreza; Hazbavi, Zeinab
2017-06-01
Quantitative response of the watershed health to climate variability is of critical importance for watershed managers. However, existing studies seldom considered the impact of climate variability on watershed health. The present study therefore aimed to analyze the temporal and spatial variability of reliability (R el ), resilience (R es ) and vulnerability (V ul ) indicators in node years of 1986, 1998, 2008 and 2014 in connection with Standardized Precipitation Index (SPI) for 24 sub-watersheds in the Shazand Watershed of Markazi Province in Iran. The analysis was based on rainfall variability as one of the main climatic drivers. To achieve the study purposes, the monthly rainfall time series of eight rain gauge stations distributed across the watershed or neighboring areas were analyzed and corresponding SPIs and R el R es V ul indicators were calculated. Ultimately, the spatial variation of SPI oriented R el R es V ul was mapped for the study watershed using Geographic Information System (GIS). The average and standard deviation of SPI-R el R es V ul index for the study years of 1986, 1998, 2008 and 2014 was obtained 0.240±0.025, 0.290±0.036, 0.077±0.0280 and 0.241±0.081, respectively. In overall, the results of the study proved the spatiotemporal variations of SPI-R el R es V ul watershed health index in the study area. Accordingly, all the sub-watersheds of the Shazand Watershed were grouped in unhealthy and very unhealthy conditions in all the study years. For 1986 and 1998 all the sub-watersheds were assessed in unhealthy status. Whilst, it declined to very unhealthy condition in 2008 and then some 75% of the watershed ultimately referred again to unhealthy and the rest still remained under very unhealthy conditions in 2014. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Prabhakaran, A.; Jawahar Raj, N.
2018-03-01
The present study attempts to understand the form and geomorphic/hydrologic processes of the 20 watersheds of the Pachamalai hills and its adjoinings located in Tamil Nadu State of southern India from the analysis of its drainage morphometric characteristics. Survey of India's topographic sheets of 1:50,000 is the data source from which stream networks and watersheds of the study area were demarcated followed by the analysis of their morphometric characteristics using ArcGIS software. The results of the analysis formed the basis for deducing the form and processes of the watersheds of the study area. The form of the watersheds inferred from the analysis includes shape, length, slope steepness and length, degree of branching of streams, dissection and elongation of watersheds. The geomorphic/hydrologic processes inferred include denudation rate, potential energy, intensity of erosion, mean annual run off, mean discharge, discharge rate, rock resistivity and infiltration potential, amount of sediment transported, mean annual rainfall, rainfall intensity, lagtime, flash flood potential, flood discharge per unit area, sediment yield and speed of the water flow in the streams. The understanding of variations of form and processes mentioned can be used towards prioritizing the watersheds for development, management and conservation planning.
An Integrated Risk Management Model for Source Water Protection Areas
Chiueh, Pei-Te; Shang, Wei-Ting; Lo, Shang-Lien
2012-01-01
Watersheds are recognized as the most effective management unit for the protection of water resources. For surface water supplies that use water from upstream watersheds, evaluating threats to water quality and implementing a watershed management plan are crucial for the maintenance of drinking water safe for humans. The aim of this article is to establish a risk assessment model that provides basic information for identifying critical pollutants and areas at high risk for degraded water quality. In this study, a quantitative risk model that uses hazard quotients for each water quality parameter was combined with a qualitative risk model that uses the relative risk level of potential pollution events in order to characterize the current condition and potential risk of watersheds providing drinking water. In a case study of Taipei Source Water Area in northern Taiwan, total coliforms and total phosphorus were the top two pollutants of concern. Intensive tea-growing and recreational activities around the riparian zone may contribute the greatest pollution to the watershed. Our risk assessment tool may be enhanced by developing, recording, and updating information on pollution sources in the water supply watersheds. Moreover, management authorities could use the resultant information to create watershed risk management plans. PMID:23202770
Decadal water quality variations at three typical basins of Mekong, Murray and Yukon
NASA Astrophysics Data System (ADS)
Khan, Afed U.; Jiang, Jiping; Wang, Peng
2018-02-01
Decadal distribution of water quality parameters is essential for surface water management. Decadal distribution analysis was conducted to assess decadal variations in water quality parameters at three typical watersheds of Murray, Mekong and Yukon. Right distribution shifts were observed for phosphorous and nitrogen parameters at the Mekong watershed monitoring sites while left shifts were noted at the Murray and Yukon monitoring sites. Nutrients pollution increases with time at the Mekong watershed while decreases at the Murray and Yukon watershed monitoring stations. The results implied that watershed located in densely populated developing area has higher risk of water quality deterioration in comparison to thinly populated developed area. The present study suggests best management practices at watershed scale to modulate water pollution.
The economic benefits of vegetation in the upstream area of Ciliwung watershed
NASA Astrophysics Data System (ADS)
Saridewi, T. R.; Nazaruddin
2018-04-01
Ciliwung watershed has strategic values since its entire downstream area is located in the Special Administrative Region of Jakarta (DKI Jakarta), the capital of Indonesia. This causes forest and farmland areas are converted into open areas or built-up areas. The existence of these areas provides enormous environmental and economic benefits. Economic benefit values are very important to be considered in developing a policy development plan, but they have not been calculated yet. This study aims to determine the economic benefits provided by trees and other vegetation anddevelops a development policy that takes into account simultaneously ecological and economic aspects. The study is conducted in the upstream Ciliwung watershed, by using land cover patterns in 1989, 2000, 2010 and 2014, and employs GIS and CITY green analysis. The results show that conversion of forest and farmland areas reduces the ability of Ciliwung upstream watershed to store water. Therefore, its ability to reduce the flow of surface has been decreased. This creates a decrease in the cost savings of annual stormwater, from US 15,175,721 in 1989 to US 13,317,469 in 2014. The Environmental Services Payment Policy (PES) for upstream community groups managing the watershed has been considered as a fairly effective policy.
Zhao, Xiaoqing; Dai, Jinhua; Wang, Jianping
2013-01-01
Land degradation is one of the significant issues the human beings are confronted with, which has become a bottleneck of restricting the sustainable development of the regional society and economy. In order to ascertain the root causes contributed to the land degradation and characteristics of land degradation, Bijiang watershed, the most important Lead-Zinc mine area of Lanping county of Yunnan Province, was selected as the study area. One evaluation index system for land degradation that consists of 5 single factors(water-soil erosion intensity, geological disaster risk, cultivation intensity of arable land, pollution of heavy metals in soil and biodiversity deterioration) was established and 13 indicators were chosen, and the entropy method was adopted to assign weights to each single factor. By using the tools of Geographic Information System (GIS), the land degradation degree was evaluated and one spatial distribution map for land degradation was accomplished. In this study, the land of the whole watershed was divided into 4 types, including extremely-severe degradation area, severely-degraded area, moderately-degraded area and slightly-degraded area, and some solutions for ecological restoration and rehabilitation were also put forward in this study. The study results indicated that: (1) Water-soil erosion intension and pollution of heavy metals in soil have made greater contribution to the comprehensive land degradation in Bijiang watershed; (2) There is an apparent difference regarding land degradation degree in Bijiang watershed. The moderately-degraded area accounts for the most part in the region, which covers 79.66% of the whole watershed. The severely-degraded area accounts for 15.98% and the slightly-degraded regions and extremely severe degradation area accounts for 1.08% and 3.28% respectively; (3) There is an evident regularity of spatial distribution in land degradation in Bijiang watershed. The moderately-degraded areas mainly distribute in the most part of the mid-stream and down-stream, the slightly-degraded areas distribute in the mid-stream, the severely-degraded areas distribute in the upstream and south-west part of down-stream, the extremely severe degradation areas distribute in the east and middle part of the upstream; (4)From the administrative division viewpoint, the slightly-degraded areas primarily distribute in Jiancao township, Baishi town and Nuodeng town. The moderately-degraded areas distribute in Changxin township, Baofeng township, Jiancao township, Baishi town and Nuodeng town. The severely-degraded areas distribute in Jinding town, Baofeng township and Lajing town. The extremely severe degradation areas distribute in Jinding town. By connecting the spatial distribution mode for land degradation with other natural, economical elements, we drew a conclusion that the pollution in heavy metals in soil, serious water erosion and geological disasters are the main causes of the land degradation in Bijiang watershed.
Volumes of recent floods and potential for storage in upland watershed areas of Iowa
Buchmiller, Robert C.; Eash, David A.; Harvey, Craig A.
2000-01-01
During the autumn of 1997, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, began a study to determine the volume of water associated with recent flood events in parts of the Midwestern United States and a preliminary evaluation of the potential upland areas for storage of flood-waters in selected watersheds. This analysis, although preliminary, may be useful in determining the feasibility of conducting additional, more detailed studies into the role of upland areas in a watershed management strategy. The methods and results of this preliminary hydrologic study are presented in this report.
Li, Yuyuan; Meng, Cen; Gao, Ru; Yang, Wen; Jiao, Junxia; Li, Yong; Wang, Yi; Wu, Jinshui
2014-05-01
Water eutrophication in subtropical regions of southern China threatens watershed health and is of major concern. However, annual phosphorus (P) loading and its dominant causes are still unclear, especially at the watershed scale. In this study, we investigated dynamic P loadings and associated factors (e.g., land use, livestock production, and runoff depth) in ten watersheds that varied in area from 9 to 5,212 ha in a hilly area of Hunan Province, China. A flowmeter was installed at the outlet of each watershed, and total P (TP) and soluble P (SP) concentrations were monitored periodically from June 2010 to October 2012. The results showed that annual P loadings (APLs) in the ten watersheds ranged from 22.8 to 247.8 kg P/km(2) and that P loss primarily occurred from April to June of each year during the main rainfall season in the study area. In addition, the average eutrophication (>0.05 mg P/L) ratio for stream waters was 86.7 % during the study period, which was indicative of a potentially serious condition for the local water environments. Annual P loadings were linearly related to livestock density (LD; R = 0.92, p < 0.01), whereas the eutrophication ratio of stream water was significantly (p < 0.05) correlated with LD (R = 0.61), percentage cropland (R = 0.71), and percentage forest cover (R = -0.68). Thus, it is concluded that the control of livestock production has the greatest potential for reducing P loadings in watersheds in this subtropical area. This will be beneficial to the amelioration and protection of local environment.
Watershed Profiles and Stream-net Structure of Vesuvio Volcano, Italy
NASA Astrophysics Data System (ADS)
Lin, Z.; Oguchi, T.; Komatsu, G.
2006-12-01
Watershed topography including stream-net structure in 32 watersheds of Vesuvio Volcano was analyzed using a DEM with a 20-m resolution, with special attention to geomorphological differences between the northern ?0-8 area and the other areas. The longitudinal and transverse profiles and stream-nets of the watersheds were extracted from the DEM. Drainage density and statistical morphometric parameters representing the shape of the profiles were investigated, and their relations with other basic morphometric parameters such as slope angle were examined. The relationships between drainage density and slope angle for each watershed can be divided into two types: Type 1 - negative correlation and Type 2 - convex-form correlation. The Type 2 watersheds have smaller bifurcation ratios and larger low-order stream lengths than the Type 1 watersheds, indicating that low-order streams in the Type 2 watersheds are more integrated. The results of longitudinal and transverse profile analyses also show that the topography of the Type 2 watersheds is simpler and more organized than that of the Type 1 watersheds, suggesting that the Type 2 watersheds are closer to equilibrium conditions. The Type 2 watersheds are located in the steepest and highest part of the somma area, where only limited eruption products have been deposited during the Holocene, due to the existence of the high and steep outer rim of the caldera at the top of the volcano. The results including the existence of the two types are similar to those from non-volcanic watersheds in Japan, indicating that stream-net studies combined with profile analysis using DEMs are effective in discussing the erosional stages of watersheds.
USDA-ARS?s Scientific Manuscript database
Most water quality studies are conducted at the plot, field, or watershed scale; however, studies that integrate the three scales provide information to scale results obtained at one scale to a greater area. The objective of this study was to analyze runoff and water quality measured (1997-2001) fr...
NASA Astrophysics Data System (ADS)
Bai, Jianwen; Shen, Zhenyao; Yan, Tiezhu
2017-09-01
An essential task in evaluating global water resource and pollution problems is to obtain the optimum set of parameters in hydrological models through calibration and validation. For a large-scale watershed, single-site calibration and validation may ignore spatial heterogeneity and may not meet the needs of the entire watershed. The goal of this study is to apply a multi-site calibration and validation of the Soil andWater Assessment Tool (SWAT), using the observed flow data at three monitoring sites within the Baihe watershed of the Miyun Reservoir watershed, China. Our results indicate that the multi-site calibration parameter values are more reasonable than those obtained from single-site calibrations. These results are mainly due to significant differences in the topographic factors over the large-scale area, human activities and climate variability. The multi-site method involves the division of the large watershed into smaller watersheds, and applying the calibrated parameters of the multi-site calibration to the entire watershed. It was anticipated that this case study could provide experience of multi-site calibration in a large-scale basin, and provide a good foundation for the simulation of other pollutants in followup work in the Miyun Reservoir watershed and other similar large areas.
NASA Astrophysics Data System (ADS)
Giberson, G. K.; Oswald, C.
2015-12-01
In areas affected by snow, chloride (Cl) salts are widely used as a de-icing agent to improve road conditions. While the improvement in road safety is indisputable, there are environmental consequences to local aquatic ecosystems. In many waterways, Cl concentrations have been increasing since the early 1990s, often exceeding national water quality guidelines. To determine the quantity of Cl that is accumulating in urban and urbanizing watersheds, accurate estimates of road salt usage at the watershed-scale are needed. The complex jurisdictional control over road salt application in southern Ontario lends itself to a geospatial approach for calculating Cl inputs to improve the accuracy of watershed-scale Cl mass balance estimates. This study will develop a geospatial protocol for combining information on road salt applications and road network areas to refine watershed-scale Cl inputs, as well as assess spatiotemporal patterns in road salt application across the southern Ontario study region. The overall objective of this project is to use geospatial methods (predominantly ArcGIS) to develop high-accuracy estimates of road salt usage in urbanizing watersheds in southern Ontario. Specifically, the aims will be to map and summarize the types and areas ("lane-lengths") of roadways in each watershed that have road salt applied to them, to determine the most appropriate source(s) of road salt usage data for each watershed, taking into consideration multiple levels of jurisdiction (e.g. municipal, regional, provincial), to calculate and summarize sub-watershed and watershed-scale road salt usage estimates for multiple years, and to analyze intra-watershed spatiotemporal patterns of road salt usage, especially focusing on impervious surfaces. These analyses will recommend areas of concern exacerbated by high-levels of road salt distribution; recommendations around modifying on-the-ground operations will be the next step in helping to correct these issues.
Turk, John T.; Parker, Randolph S.
1982-01-01
Analysis of major and trace constituents in streams flowing through six semiarid watersheds indicates that the stream chemistry is characterized by saturation with respect to common carbonate minerals (calcium, magnesium, iron, manganese, and lead). The solubility of the carbonate minerals may be a major control on the absolute and relative concentrations of calcium, magnesium, bicarbonate, iron, manganese, and lead; however, other mechanisms probably control the concentrations of cadmium and zinc. Statistical analyses indicate that the mean concentrations of the major ions in the two climatic areas studied are significantly (P=0.05) different from one another, with larger mean concentrations in the more arid area. Trace-metal concentrations were similar from one area to another and indistinguishable from site to site (P=0.05) for lead, cadmium, and zinc. Linear regressions of major ion concentration to specific conductance are similar in both areas for sodium, bicarbonate, sulfate, and chloride. Results of the study may be useful in providing a first approximation of stream chemistry in other watersheds with the same geologic setting, determining watersheds with similar geochemical controls, and determining future changes in stream chemistry in the watersheds studied. (USGS)
Vonlanthen, P; Excoffier, L; Bittner, D; Persat, H; Neuenschwander, S; Largiadèr, C R
2007-11-01
Natural colonizations across watersheds have been frequently proposed to explain the present distributions of many freshwater fish species. However, detailed studies of such potential watershed crossings are still missing. Here, we investigated potential postglacial watershed crossings of the widely distributed European bullhead (Cottus gobio L.) in two different areas along the Rhine-Rhône watershed using detailed genetic analysis. The main advantage of studying bullheads vs. other freshwater fish species is that their distribution has been lightly influenced by human activities and as such, interpretations of colonization history are not confounded by artificial transplantations. The genetic analyses of eight microsatellite loci revealed strong genetic similarities between populations of both sides of the Rhine-Rhône watershed in the Lake Geneva area, giving strong evidence for a natural watershed crossing of bullheads from the upper Rhine drainage into the Rhône drainage in the Lake Geneva area likely facilitated by the retreat of the glaciers after the last glacial maximum some 20,000 years ago. Populations from the Lake Geneva basin were genetically more similar to populations from across the watershed in the upper Rhine drainage than to populations further downstream in the lower Rhône. In contrast, populations from Belfort, an area, which was not covered by ice during the last glacial maximum, showed strong genetic differentiation between populations of the upper Rhine and Rhône drainages. Based on our results on the bullhead, we propose that glacial retreat may have eased the dispersal of numerous European freshwater fish species across several geological boundaries.
Prioritizing watersheds for conservation actions in the southeastern coastal plain ecoregion.
Jang, Taeil; Vellidis, George; Kurkalova, Lyubov A; Boll, Jan; Hyman, Jeffrey B
2015-03-01
The aim of this study was to apply and evaluate a recently developed prioritization model which uses the synoptic approach to geographically prioritize watersheds in which Best Management Practices (BMPs) can be implemented to reduce water quality problems resulting from erosion and sedimentation. The model uses a benefit-cost framework to rank candidate watersheds within an ecoregion or river basin so that BMP implementation within the highest ranked watersheds will result in the most water quality improvement per conservation dollar invested. The model was developed to prioritize BMP implementation efforts in ecoregions containing watersheds associated with the USDA-NRCS Conservation Effects Assessment Project (CEAP). We applied the model to HUC-8 watersheds within the southeastern Coastal Plain ecoregion (USA) because not only is it an important agricultural area but also because it contains a well-studied medium-sized CEAP watershed which is thought to be representative of the ecoregion. The results showed that the three HUC-8 watersheds with the highest rankings (most water quality improvement expected per conservation dollar invested) were located in the southern Alabama, northern Florida, and eastern Virginia. Within these watersheds, measures of community attitudes toward conservation practices were highly ranked, and these indicators seemed to push the watersheds to the top of the rankings above other similar watersheds. The results, visualized as maps, can be used to screen and reduce the number of watersheds that need further assessment by managers and decision-makers within the study area. We anticipate that this model will allow agencies like USDA-NRCS to geographically prioritize BMP implementation efforts.
Linking watershed nitrogen sources with nitrogen dynamics in rivers of western Oregon, USA
We found a wide range of riverine N yields from the study basins, ranging from one to 70 kg N/ha/yr. Across the study basins, N export was more strongly correlated to fertilizer application rates than percent of agricultural area in the watershed. Low watershed N yields reflect...
Chaplin, Jeffrey J.
2005-01-01
Natural-stream designs are commonly based on the dimensions of the bankfull channel, which is capable of conveying discharges that transport sediment without excessive erosion or deposition. Regional curves relate bankfull-channel geometry and discharge to drainage area in watersheds with similar runoff characteristics and commonly are utilized by practitioners of natural-stream design to confirm or refute selection of the field-identified bankfull channel. Data collected from 66 streamflow-gaging stations and associated stream reaches between December 1999 and December 2003 were used in one-variable ordinary least-squares regression analyses to develop regional curves relating drainage area to cross-sectional area, discharge, width, and mean depth of the bankfull channel. Watersheds draining to these stations are predominantly within the Piedmont, Ridge and Valley, and Appalachian Plateaus Physiographic Provinces of Pennsylvania and northern Maryland. Statistical analyses of physiography, percentage of watershed area underlain by carbonate bedrock, and percentage of watershed area that is glaciated indicate that carbonate bedrock, not physiography or glaciation, has a controlling influence on the slope of regional curves. Regional curves developed from stations in watersheds underlain by 30 percent or less carbonate bedrock generally had steeper slopes than the corresponding relations developed from watersheds underlain by greater than 30 percent carbonate bedrock. In contrast, there is little evidence to suggest that regional curves developed from stations in the Piedmont or Ridge and Valley Physiographic Province are different from the corresponding relations developed from stations in the Appalachian Plateaus Physiographic Province. On the basis of these findings, regional curves are presented to represent two settings that are independent of physiography: (1) noncarbonate settings characterized by watersheds with carbonate bedrock underlying 30 percent or less of watershed area, and (2) carbonate settings characterized by watersheds with carbonate bedrock underlying greater than 30 percent of watershed area. All regional curves presented in this report have slopes that are significantly different from zero and normally distributed residuals that vary randomly with drainage area. Drainage area explains the most variability in bankfull cross-sectional area and bankfull discharge in the noncarbonate setting (R2 = 0.92 for both). Less variability is explained in bankfull width and depth (R2 = 0.81 and 0.72, respectively). Regional curves representing the carbonate setting are generally not as statistically robust as the corresponding noncarbonate relations because there were only 11 stations available to develop these curves and drainage area cannot explain variance resulting from karst features. The carbonate regional curves generally are characterized by less confidence, lower R2 values, and higher residual standard errors. Poor representation by watersheds less than 40 mi2 causes the carbonate regional curves for bankfull discharge, cross-sectional area, and mean depth to be disproportionately influenced by the smallest watershed (values of Cook's Distance range from 3.6 to 8.4). Additional bankfull discharge and channel-geometry data from small watersheds might reduce this influence, increase confidence, and generally improve regional curves representing the carbonate setting. Limitations associated with streamflow-gaging station selection and development of the curves result in some constraints for the application of regional curves presented in this report. These curves apply only to streams within the study area in watersheds having land use, streamflow regulation, and drainage areas that are consistent with the criteria used for station selection. Regardless of the setting, the regional curves presented here are not intended for use as the sole method for estimation of bankfull characteristics; however, th
[Impact on nitrogen and phosphorous export of wetlands in Tianmu Lake watershed].
Li, Zhao-Fu; Liu, Hong-Yu; Li, Heng-Peng
2012-11-01
Focused on understanding the function of wetland in improving water quality, Pingqiao watershed and Zhongtian watershed in Tianmu Lake drinking water sources area were selected as the research region. We integrated remote sensing, GIS techniques with field investigation and chemical analysis to analyze the relationship between wetland and water quality in watershed scale. Results show: (1) There are many wetland patches in Pingqiao and Zhongtian watershed, wetlands patch densities were respectively 7.5 km(-2) and 7.1 km(-2). Wetlands widely distributed in the Pingqiao watershed with mostly located away from the river of 500 m, whereas wetlands relatively concentrated in the lower reach within 500 meters of riverside in Zhongtian watershed. (2) Nitrogen and phosphorus nutrient retention of wetland in watershed scale was significant. The annual mean TN and DTN concentration had a strong relationship with percent area of wetlands in Zhongtian watershed while the weakest relationship was found with TP and DTP concentrations, especially, the mean TN and DTN concentrations in spring and winter had the significantly negative relationship with wetland areas of watershed. The negative relationship was existed for nitrogen in autumn of Pingqiao watershed, which suggested that watersheds varying in area of wetlands have the different nutrient reducing efficiency in seasonal periods. (3) A certain number and area of wetland will improve river water quality in watershed scale, which can instruct water environment treatment. However, considering the complexity of nutrient transport processes in watershed, wetland-related factors such as area, location, density, ecosystem structure and watershed-related factors such as temporal interval, spatial scales, slope and land use will impact on the transport processes, and related theoretical and practical problems need further research.
AN ARCGIS TOOL FOR CREATING POPULATIONS OF WATERSHEDS
For the Landscape Investigations for Pesticides Study in the Midwest, the goal is to sample a representative subset of watersheds selected statistically from a target population of watersheds within the glaciated corn belt. This area stretches from Ohio to Iowa and includes parts...
Byoungkoo Choi; Jeff A. Hatten; Janet C. Dewey; Kyoichi Otsuki; Dusong Cha
2013-01-01
Headwater streams are crucial parts of overall watershed dynamics because they comprise more than 50â80% of stream networks and watershed land areas. This study addressed the influence of headwater areas (ephemeral and intermittent) on stormflow characteristics following harvest within three firstâorder catchments in the Upper Gulf Coastal Plain of Mississippi. Four...
2012-07-01
water quality, potential for growth of invasive species , and fish and wildlife habitat . Clinton River and Anchor Bay Watersheds Reconnaissance...However, the study area provides important habitat for many rare species , with the most abundant being wooded areas. In addition, the study area features...animal life and provide spawning grounds for fish. These areas provide habitat for numerous species , including rare species such as black- crowned
Nielsen, M.G.; Kahl, J.S.
2007-01-01
A study of 13 small (less than 7.5 km2) watersheds on Mt. Desert Island, Maine, was conducted from January 1999 to September 2000 to determine nutrient export delivery to coastal waters around the island, and to determine whether a series of wildfires in 1947 have affected nutrient export in burned watersheds. Nutrient export (nitrate-nitrogen, total nitrogen, total phosphorus) was determined for each watershed during the study period, and was normalized by watershed area. The yield of nitrate-nitrogen (N) ranged from 10 to 140 kg/km2/year. Total N yield ranged from 42 to 250 kg/ km2/year. Total phosphorus (P) yield ranged from 1.4 to 7.9 kg/km2/year. Watersheds entirely within Acadia National Park (lacking human land-based nutrient sources) exported significantly less total N and total P than watersheds that were partly or entirely outside the park boundary. Nitrate-N export was not significantly different in these two groups of watersheds, perhaps because atmospheric deposition is a dominant source of nitrate in the study area. No relation was observed between burn history and nutrient export. Any effect of burn history may be masked by other landscape-level factors related to nutrient export. ?? Springer Science + Business Media B.V. 2007.
Effect of scale on the behavior of atrazine in surface waters
Capel, P.D.; Larson, S.J.
2001-01-01
Field runoff is an important transport mechanism by which agricultural pesticides, including atrazine, move into the hydrologic environment. Atrazine is chosen because it is widely used, is transported in runoff relatively easily, is widely observed in surface waters, and has relatively little loss in the stream network. Data on runoff of atrazine from experimental plot and field studies is combined with annual estimates of load in numerous streams and rivers, resulting in a data set with 408 observations that span 14 orders of magnitude in area. The load as a percent of use (LAPU) on an annual basis is the parameter that is compared among the studies. There is no difference in the mean or range of LAPU values for areas from the size of experimental field plots (???0.000023 ha) and small watersheds (<100 000 ha). The relatively invariant LAPU value observed across a large range of watershed areas implies that the characteristics of atrazine itself (application method and chemical properties) are important in determining the extent of runoff. The variable influences on the extent of runoff from individual watershed characteristics and weather events are superimposed on the relatively invariant LAPU value observed across the range of watershed areas. The results from this study establish the direct relevance for agricultural field plot studies to watershed studies across the full range of scale.
Griffiths, Natalie A.; Jackson, C. Rhett; McDonnell, Jeffrey J.; ...
2016-02-08
Nitrogen (N) is an important nutrient as it often limits productivity but in excess can impair water quality. Most studies on watershed N cycling have occurred in upland forested catchments where snowmelt dominates N export; fewer studies have focused on low-relief watersheds that lack snow. We examined watershed N cycling in three adjacent, low-relief watersheds in the Upper Coastal Plain of the southeastern United States to better understand the role of hydrological flow paths and biological transformations of N at the watershed scale. Groundwater was the dominant source of nitrified N to stream water in two of the three watersheds,more » while atmospheric deposition comprised 28% of stream water nitrate in one watershed. The greater atmospheric contribution may have been due to the larger stream channel area relative to total watershed area or the dominance of shallow subsurface flow paths contributing to stream flow in this watershed. There was a positive relationship between temperature and stream water ammonium concentrations and a negative relationship between temperature and stream water nitrate concentrations in each watershed suggesting that N cycling processes (i.e., nitrification and denitrification) varied seasonally. However, there were no clear patterns in the importance of denitrification in different water pools possibly because a variety of factors (i.e., assimilatory uptake, dissimilatory uptake, and mixing) affected nitrate concentrations. In conclusion, together, these results highlight the hydrological and biological controls on N cycling in low-gradient watersheds and variability in N delivery flow paths among adjacent watersheds with similar physical characteristics.« less
Land suitability assessment on a watershed of Loess Plateau using the analytic hierarchy process.
Yi, Xiaobo; Wang, Li
2013-01-01
In order to reduce soil erosion and desertification, the Sloping Land Conversion Program has been conducted in China for more than 15 years, and large areas of farmland have been converted to forest and grassland. However, this large-scale vegetation-restoration project has faced some key problems (e.g. soil drying) that have limited the successful development of the current ecological-recovery policy. Therefore, it is necessary to know about the land use, vegetation, and soil, and their inter-relationships in order to identify the suitability of vegetation restoration. This study was conducted at the watershed level in the ecologically vulnerable region of the Loess Plateau, to evaluate the land suitability using the analytic hierarchy process (AHP). The results showed that (1) the area unsuitable for crops accounted for 73.3% of the watershed, and the main factors restricting cropland development were soil physical properties and soil nutrients; (2) the area suitable for grassland was about 86.7% of the watershed, with the remaining 13.3% being unsuitable; (3) an area of 3.95 km(2), accounting for 66.7% of the watershed, was unsuitable for forest. Overall, the grassland was found to be the most suitable land-use to support the aims of the Sloping Land Conversion Program in the Liudaogou watershed. Under the constraints of soil water shortage and nutrient deficits, crops and forests were considered to be inappropriate land uses in the study area, especially on sloping land. When selecting species for re-vegetation, non-native grass species with high water requirements should be avoided so as to guarantee the sustainable development of grassland and effective ecological functioning. Our study provides local land managers and farmers with valuable information about the inappropriateness of growing trees in the study area along with some information on species selection for planting in the semi-arid area of the Loess Plateau.
Land Suitability Assessment on a Watershed of Loess Plateau Using the Analytic Hierarchy Process
Yi, Xiaobo; Wang, Li
2013-01-01
In order to reduce soil erosion and desertification, the Sloping Land Conversion Program has been conducted in China for more than 15 years, and large areas of farmland have been converted to forest and grassland. However, this large-scale vegetation-restoration project has faced some key problems (e.g. soil drying) that have limited the successful development of the current ecological-recovery policy. Therefore, it is necessary to know about the land use, vegetation, and soil, and their inter-relationships in order to identify the suitability of vegetation restoration. This study was conducted at the watershed level in the ecologically vulnerable region of the Loess Plateau, to evaluate the land suitability using the analytic hierarchy process (AHP). The results showed that (1) the area unsuitable for crops accounted for 73.3% of the watershed, and the main factors restricting cropland development were soil physical properties and soil nutrients; (2) the area suitable for grassland was about 86.7% of the watershed, with the remaining 13.3% being unsuitable; (3) an area of 3.95 km2, accounting for 66.7% of the watershed, was unsuitable for forest. Overall, the grassland was found to be the most suitable land-use to support the aims of the Sloping Land Conversion Program in the Liudaogou watershed. Under the constraints of soil water shortage and nutrient deficits, crops and forests were considered to be inappropriate land uses in the study area, especially on sloping land. When selecting species for re-vegetation, non-native grass species with high water requirements should be avoided so as to guarantee the sustainable development of grassland and effective ecological functioning. Our study provides local land managers and farmers with valuable information about the inappropriateness of growing trees in the study area along with some information on species selection for planting in the semi-arid area of the Loess Plateau. PMID:23922723
On the Scaling Behavior of Reliability-Resilience-Vulnerability ...
Risk indices such as reliability-resilience-vulnerability (R-R-V) have been proposed to assess watershed health. In this study, the spatial scaling behavior of R-R-V indices has been explored for five agricultural watersheds in the midwestern United States. The study was conducted using two different measures of spatial scale: (i) the ratio of contributing upland area to area required for channel initiation (FA), and (ii) Strahler stream order. It was found that R-R-V indices do change with spatial scale, but a representative watershed-specific threshold FA value exists for these indices to achieve stable values. Scaling with Strahler stream order is feasible if the watershed possesses a tree-like stream network. As an example of anthropogenic influences, this study also examined the role of BMPs placed within an agricultural watershed via a cost-effective optimization scheme on the evolution of R-R-V values with scale. While the placement of BMPs acheived reductions in concentrations and/or loads of constituents, they may not significantly change watershed risk measures, but are likely to cause significant reduction in vulnerability. If primarily upland BMPs are placed in a diffuse manner throughout the watershed, there might not be a significant change in the scaling behavior of R-R-V values. The primary objective of this study is to investigate the effect of spatial scale on risk-based watershed health assessment. A related objective is to examine wh
Banta, J. Ryan; Slattery, Richard N.
2012-01-01
Woody vegetation, including ashe juniper (Juniperus ashei), has encroached on some areas in central Texas that were historically oak grassland savannah. Encroachment of woody vegetation is generally attributed to overgrazing and fire suppression. Removing the ashe juniper and allowing native grasses to reestablish in the area as a brush management conservation practice (hereinafter referred to as "brush management") might change the hydrology in the watershed. These hydrologic changes might include changes to surface-water runoff, evapotranspiration, or groundwater recharge. The U.S. Geological Survey (USGS), in cooperation with Federal, State, and local partners, examined the hydrologic effects of brush management in two adjacent watersheds in Comal County, Tex. Hydrologic data were collected in the watersheds for 3-4 years (pre-treatment) depending on the type of data, after which brush management occurred on one watershed (treatment watershed) and the other was left in its original condition (reference watershed). Hydrologic data were collected in the study area for another 6 years (post-treatment). These hydrologic data included rainfall, streamflow, evapotranspiration, and water quality. Groundwater recharge was not directly measured, but potential groundwater recharge was calculated by using a simplified mass balance approach. This fact sheet summarizes highlights of the study from the USGS Scientific Investigations Report on which it is based.
Inter-generationally prudent management of watershed resources will require attention to the interdependence between shifting landuse distributions and their effects on watershed hydrology. Development and increased proportion of impervious surface area has been found to alte lan...
Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping
2017-12-01
Socioeconomic development in lake watersheds is closely related with lake nutrient pollution. As the second largest freshwater lake in China, the Dongting Lake has been experiencing an increase in nutrient loading and a growing risk of eutrophication. This study aimed to reveal the likely impacts of the socioeconomic development of the Dongting Lake watershed on the phosphorous pollution in the lake. We estimated the contributions from different sources and sub-watersheds to the total phosphorous (TP) export and loading from the Dongting Lake watershed under two most likely socioeconomic development scenarios. Moreover, we predicted the likely permissible and actual TP loadings to the Dongting Lake. Under both two scenarios, three secondary sub-watersheds-the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area-are expected to dominate the contribution to the TP export from the Dongting Lake watershed in 2020. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-are predicted to be the major contributors to the TP loading from the entire watershed. The two scenarios are expected to have a slight difference in TP export and lake TP loading. Livestock husbandry is expected to be the predominant anthropogenic TP source in each of the sub-watersheds under both scenarios. Compared to 2010, permissible TP loading is not expected to increase but actual TP loading is predicted to grow significantly in 2020. Our study provides methodologies to identify the key sources and regions of lake nutrient loading from watersheds with complex socioeconomic context, and to reveal the potential influences of socioeconomic development on nutrient pollution in lake watersheds.
Socioeconomic issues for the Bear River Watershed Conservation Land Area Protection Plan
Thomas, Catherine Cullinane; Huber, Christopher; Gascoigne, William; Koontz, Lynne
2012-01-01
The Bear River Watershed Conservation Area is located in the Bear River Watershed, a vast basin covering fourteen counties across three states. Located in Wyoming, Utah, and Idaho, the watershed spans roughly 7,500 squares miles: 1,500 squares miles in Wyoming; 2,700 squares miles in Idaho; and 3,300 squares miles in Utah (Utah Division of Water Resources, 2004). Three National Wildlife Refuges are currently contained within the boundary of the BRWCA: the Bear River Migratory Bird Refuge in Utah, the Bear Lake National Wildlife Refuge in Idaho, and the Cokeville Meadows National Wildlife Refuge in Wyoming. In 2010, the U.S. Fish and Wildlife Service conducted a Preliminary Project Proposal and identified the Bear River Watershed Conservation Area as having high-value wildlife habitat. This finding initiated the Land Protection Planning process, which is used by the U.S. Fish and Wildlife Service to study land conservation opportunities including adding lands to the National Wildlife Refuge System. The U.S. Fish and Wildlife Service proposes to include part of the Bear River Watershed Conservation Area in the Refuge System by acquiring up to 920,000 acres of conservation easements from willing landowners to maintain landscape integrity and habitat connectivity in the region. The analysis described in this report provides a profile of the social and economic conditions in the Bear River Watershed Conservation Area and addresses social and economic questions and concerns raised during public involvement in the Land Protection Planning process.
An index based methodology is presented that rank the sub-areas in a watershed based on their relative impacts on watershed response to anticipated land developments. We argue in this paper that the spatial locations of such critical areas are dependent on the extent of watershed...
Mapping Land Use/Land Cover in the Ambos Nogales Study Area
Norman, Laura M.; Wallace, Cynthia S.A.
2008-01-01
The Ambos Nogales watershed, which surrounds the twin cities of Nogales, Arizona, United States and Nogales, Sonora, Mexico, has a history of problems related to flooding. This paper describes the process of creating a high-resolution, binational land-cover dataset to be used in modeling the Ambos Nogales watershed. The Automated Geospatial Watershed Assessment tool will be used to model the Ambos Nogales watershed to identify focal points for planning efforts and to anticipate ramifications of implementing detention reservoirs at certain watershed planes.
Land Use Patterns and Fecal Contamination of Coastal Waters in Western Puerto Rico
NASA Technical Reports Server (NTRS)
Norat, Jose
1994-01-01
The Department of Environmental Health of the Graduate School of Public Health of the Medical Sciences Campus, University of Puerto Rico (UPR-RCM) conducted this research project on how different patterns of land use affect the microbiological quality of rivers flowing into Mayaguez Bay in Western Puerto Rico. Coastal shellfish growing areas, stream and ocean bathing beaches, and pristine marine sites in the Bay are affected by the discharge of the three study rivers. Satellite imagery was used to study watershed land uses which serve as point and nonpoint sources of pathogens affecting stream and coastal water users. The study rivers drain watersheds of different size and type of human activity (including different human waste treatment and disposal facilities). Land use and land cover in the study watersheds were interpreted, classified and mapped using remotely sensed images from NASA's Landsat Thematic Mapper (TM). This study found there is a significant relationship between watershed land cover and microbiological water quality of rivers flowing into Mayaguez Bay in Western Puerto Rico. Land covers in the Guanajibo, Anasco, and Yaguez watersheds were classified into forested areas, pastures, agricultural zones and urban areas so as to determine relative contributions to fecal water contamination. The land cover classification was made processing TM images with IDRISI and ERDAS software.
Riparian and upland vegetation on the Kings River Experimental Watershed, Sierra Nevada, California
Christopher R. Dolanc; Carolyn T. Hunsaker
2007-01-01
The Kings River Experimental Watershed (KREW) is a watershed-level study on headwater streams in the Sierra Nevada, California. Eight perennial streams, from 1500 m (4920 ft) to 2490 m (8170 ft) elevation, have been instrumented and collecting data since 2002. Component research areas of the study include stream flow, water chemistry, sediment, soil chemistry, stream...
Natural Reforestation Reclaims a Watershed: A Case History from West Virginia
W.P. Lima; J.H. Patric; N. Holowaychuk
1978-01-01
Thirteen years of hydrologic data from two contiguous small watersheds in West Virginia were analyzed to determine the effects on streamflow of natural reforestation on abandoned farmlands. During the study period (1958-1970), streamflow on the watersheds was unchanged. The history of land use on the study area helps explain the apparent lack of hydrologic effects of...
Giri, Subhasis; Qiu, Zeyuan; Zhang, Zhen
2018-05-01
Understanding the relationship between land use and water quality is essential to improve water quality through carefully managing landscape change. This study applies a linear mixed model at both watershed and hydrologically sensitive areas (HSAs) scales to assess such a relationship in 28 northcentral New Jersey watersheds located in a rapidly urbanizing region in the United States. Two models differ in terms of the geographic scope used to derive land use matrices that quantify land use conditions. The land use matrices at the watershed and HSAs scales represent the land use conditions in these watersheds and their HSAs, respectively. HSAs are the hydrological "hotspots" in a watershed that are prone to runoff generation during storm events. HSAs are derived using a soil topographic index (STI) that predicts hydrological sensitivity of a landscape based on a variable source area hydrology concept. The water quality indicators in these models are total nitrogen (TN), total phosphorus (TP) and total suspended solids (TSS) concentrations in streams observed at the watershed outlets. The modeling results suggest that presence of low density urban land, agricultural land and wetlands elevate while forest decreases TN, TP and/or TSS concentrations in streams. The watershed scale model tends to emphasize the role of agricultural lands in water quality degradation while the HSA scale model highlights the role of forest in water quality improvement. This study supports the hypothesis that even though HSAs are relatively smaller area compared to watershed, still the land uses within HSAs have similar impacts on downstream water quality as the land uses in entire watersheds, since both models have negligible differences in model evaluation parameters. Inclusion of HSAs brings an interesting perspective to understand the dynamic relationships between land use and water quality. Copyright © 2018 Elsevier Ltd. All rights reserved.
Emerald Lake Watershed study: Introduction and site description
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tonnessen, K.A.
1991-07-01
The Emerald Lake Watershed study was organized to investigate the effects of acidic deposition on high-elevation watersheds and surface waters of the Sierra Nevada, California. Some of the results of this comprehensive study of aquatic and terrestrial ecosystems at a small, headwater basin are presented in four papers in this series. The watershed study site is in Sequoia National Park, on the western slope of the Sierra Nevada. This glacial cirque is located in the upper Marble Fork of the Kaweah River. This 120-ha watershed ranges from Alta Peak (3,416 m) down to Emerald Lake (2,400 m). Most of themore » watershed surface area is exposed granite and granodiorite rocks, with limited coverage (about 20%) by thin, acidic soils. The hydrology of the basin is dominated by snowmelt runoff during March-June. Emerald Lake, a glacial tarn, is 2.72 ha in area, with a maximum depth of 10.5 m. Surface waters are poorly buffered and dominated by calcium and bicarbonate. Most of the yearly precipitation falls as dilute snow (pH5.2-5.4), with acidic rain storms sampled during May-October.« less
A Review on Flood Events for Kelantan River Watershed in Malaysia for Last Decade (2001-2010)
NASA Astrophysics Data System (ADS)
Aminah Shakirah, J.; Sidek, L. M.; Hidayah, B.; Nazirul, M. Z.; Jajarmizadeh, M.; Ros, F. C.; Roseli, ZA
2016-03-01
Malaysia is located at tropical zone and high precipitation area that frequently hit by flood events when it is near monsoon season. This hydro hazard has been one of the main concerns for governmental and non-governmental sectors. High floods lead in financial damages and they are related with human’s life. Kelantan watershed is one of the challenging watersheds which mostly suffer from flood events and heavy rainfall events. Flood in Kelantan watershed is related with monetary misfortunes and lives. Clearly, flood have significant influence on various water sectors such water supply, agriculture, human health and ecosystems therefore study of this topic and presentation of available of any data and information can be a valuable baseline for upcoming research in vulnerable case studies. In this study, Kelantan watershed is selected because it is prone to flooding and urban areas classified as vulnerable districts. This overview is discussed on the last decade (2001-2010) floods events in Kelantan.
Keller, D S; Joshi, H M; Rodriguez-Justo, M; Walsh, D; Coffey, J C; Chand, M
2017-09-01
Recent advances in mesenteric science have demonstrated that the mesentery is a continuous structure with a 'watershed' area at the mesenteric apex between the right colon and terminal ileum, where lymphatic flow can proceed either proximally or distally. With this new understanding of the anatomy, functional features are emerging, which can have an impact on surgical management. Fluorescence lymphangiography or lymphoscintigraphy with indocyanine green allows real-time visualization of lymphatic channels, which highlights sentinel lymph nodes and may facilitate identification of the ideal margins for mesenteric lymphadenectomy during bowel resection for colon cancer. By using this novel technology, it is possible to demonstrate a watershed area in the ileocolic region and may facilitate more precise mesenteric dissection. In the present study, we provide proof of concept for the ileocolic watershed area using fluorescence lymphangiography.
Wolfand, Jordyn M; Bell, Colin D; Boehm, Alexandria B; Hogue, Terri S; Luthy, Richard G
2018-06-05
Stormwater best management practices (BMPs) are implemented to reduce microbial pollution in runoff, but their removal efficiencies differ. Enhanced BMPs, such as those with media amendments, can increase removal of fecal indicator bacteria (FIB) in runoff from 0.25-log 10 to above 3-log 10 ; however, their implications for watershed-scale management are poorly understood. In this work, a computational model was developed to simulate watershed-scale bacteria loading and BMP performance using the Ballona Creek Watershed (Los Angeles County, CA) as a case study. Over 1400 scenarios with varying BMP performance, percent watershed area treated, BMP treatment volume, and infiltrative capabilities were simulated. Incremental improvement of BMP performance by 0.25-log 10 , while keeping other scenario variables constant, reduces annual bacterial load at the outlet by a range of 0-29%. In addition, various simulated scenarios provide the same FIB load reduction; for example, 75% load reduction is achieved by diverting runoff from either 95% of the watershed area to 25 000 infiltrating BMPs with 0.5-log 10 removal or 75% of the watershed area to 75 000 infiltrating BMPs with 1.5-log 10 removal. Lastly, simulated infiltrating BMPs provide greater FIB reduction than noninfiltrating BMPs at the watershed scale. Results provide new insight on the trade-offs between BMP treatment volume, performance, and distribution.
F.N. SCATENA
1990-01-01
Interception losses were monitored for one year and related to vegetation characteristics in two forested watersheds in the Luquillo Experimental Forest of Puerto Rico. Total watershed interception was then modeled by weighting values of throughfall measured in representative areas of different vegetation types by the total watershed area of that vegetation group....
Daniel G. Neary; Peter R. Robichaud; Jan L. Beyers
2000-01-01
Following wildfires, burned areas are assessed by special teams to determine if emergency watershed rehabilitation measures are required to restore watershed function and minimize damage to soil resources. The objective of burned area emergency rehabilitation (BAER) treatments is to restore watershed condition and reduce erosional losses on hillslopes, in channels, and...
INTENSIVE WATERSHED STUDY: THE PATUXENT RIVER BASIN
This study was one of five intensive watershed studies designed by the Chesapeake Bay Program's Eutrophication Work Group to provide detailed nonpoint source loading rates and ambient water quality data within the Chesapeake Bay drainage area. The study was conducted within the P...
Effects of forest cover and environmental variables on snow accumulation and melt
Mariana Dobre; William J. Elliot; Joan Q. Wu; Timothy E. Link; Ina S. Miller
2011-01-01
The goal of this study was to assess the effects of topography and forest cover resulting from different treatments on snow accumulation and melt in small watersheds in the western United States. A paired-watershed study was implemented at the Priest River Experimental Forest, Idaho, where 10 small watersheds with an average area of 4.5 ha were treated by: 1) control (...
Geological risk assessment for the rapid development area of the Erhai Basin
NASA Astrophysics Data System (ADS)
Yang, Liu; Wang, Zhanqi; Jin, Gui; Chen, Dongdong; Wang, Zhan
For low-slope hilly land development to have more new land space in a watershed, it is particularly important that to coordinate the sharply increasing conflicts between mountainous and urban land utilization in the city. However, development of low-slope hilly land easily induce potential risks of geologic hazards such as landslide and landslip. It may lead to further environmental losses in a watershed. Hence, it is necessary to study potential risks of geo-hazards in low-slope hilly land development in urban area. Based on GIS spatial analysis technique, we select a study area, Dali City in the Erhai Basin located in watershed belt of Jinsha River, Lancang River and Red River in Yunnan Province of China. Through studying some relevant key indexes and parameters for monitoring potential risks of geo-hazards, we establish a composite index model for zoning the area with potential risks of geo-hazards in development of low-slope hilly land in the study area. Our research findings indicate that the potential risks of geo-hazards in eastern Dali City is relatively low while of that on slow hills with gentle slopes in the western area are relatively high. By using a zoning research method, generated maps show geological information of potential risks of geo-hazards on low-slope hilly land which provide important messages for guarding against natural geo-hazards and potential environmental losses in a watershed.
Identifying change in spatial accumulation of soil salinity in an inland river watershed, China.
Wang, Yugang; Deng, Caiyun; Liu, Yan; Niu, Ziru; Li, Yan
2018-04-15
Soil salinity accumulation is strong in arid areas and it has become a serious environmental problem. Knowledge of the process and spatial changes of accumulated salinity in soil can provide an insight into the spatial patterns of soil salinity accumulation. This is especially useful for estimating the spatial transport of soil salinity at the watershed scale. This study aimed to identify spatial patterns of salt accumulation in the top 20cm soils in a typical inland watershed, the Sangong River watershed in arid northwest China, using geostatistics, spatial analysis technology and the Lorenz curve. The results showed that: (1) soil salt content had great spatial variability (coefficient variation >1.0) in both in 1982 and 2015, and about 56% of the studied area experienced transition the degree of soil salt content from one class to another during 1982-2015. (2) Lorenz curves describing the proportions of soil salinity accumulation (SSA) identified that the boundary between soil salinity migration and accumulation regions was 24.3m lower in 2015 than in 1982, suggesting a spatio-temporal inequality in loading of the soil salinity transport region, indicating significant migration of soil salinity from the upstream to the downstream watershed. (3) Regardless of migration or accumulation region, the mean value of SSA per unit area was 0.17kg/m 2 higher in 2015 than 1982 (p<0.01) and the increasing SSA per unit area in irrigated land significantly increased by 0.19kg/m 2 compared with the migration region. Dramatic accumulation of soil salinity in all land use types was clearly increased by 0.29kg/m 2 in this agricultural watershed during the studied period in the arid northwest of China. This study demonstrates the spatial patterns of soil salinity accumulation, which is particularly useful for estimating the spatial transport of soil salinity at the watershed scale. Copyright © 2017 Elsevier B.V. All rights reserved.
Stratified random selection of watersheds allowed us to compare geographically-independent classification schemes based on watershed storage (wetland + lake area/watershed area) and forest fragmentation with a geographically-based classification scheme within the Northern Lakes a...
Using surveys as input to comprehensive watershed management: a case study from Minnesota.
Tim Kelly; Ron Sushak
1996-01-01
As a compliment to direct citizen participation, the Minnesota Department of Natural Resources used a survey of area landowners to help inform its comprehensive watershed management initiative. Results from the survey have been useful to resource managers and area residents as they carry out this planning effort.
DOT National Transportation Integrated Search
2016-04-01
The new lag-time equation for the Kansas City area performs better than the 2001 KU-KDOT equation for urban lag time, which was developed from a study of 14 gaged watersheds in Johnson County (McEnroe & Zhao, 2001). The main advantage of the new lag-...
Analysis of Potential Deep-Seated Landslide in Hekeng Watershed by Environment Indices
NASA Astrophysics Data System (ADS)
Hsieh, C. J.; Chompuchan, C.
2014-12-01
Landslides are a major natural disaster in Taiwan relevant to the human life. After the catastrophic Xiaolin landslide during Typhoon Morakot in August 2009 caused around 400 casualties, the deep-seated landslide has become a serious issue. This study explored the potential deep-seated landslide in Hekeng watershed extracted from SPOT-5 imageries. The empirical topographic correction was applied to minimize effect of the mountain shaded area due to the difference of sun elevation and terrain angle. Consequently the multi-temporal environmental indices, i.e., modified Normalized Difference Vegetation Index (mNDVI) and modified Normalized Difference Water Index (mNDWI) were corrected. Seasonal vegetation cover and surface moisture change were analyzed incorporate with a slope which obtain from DEM data. The result showed that the distribution of potential deep-seated landslide vulnerable area mainly located at headstream watershed. It could be explained that the headstream watershed has less human interference, therefore the environmental indices interpreted those area as deep soil layer and dense vegetation coverage. However, the upstream canal could suffer from the long-term erosion and possibly cause slope toe collapse. In addition, the western watershed is the afforestation zone whereas the eastern watershed is natural forest zone with higher development ratio. The upslope forest management of eastern and western watershed should be discussed variously.
Martin, Jeffrey D.; Duwelius, Richard F.; Crawford, Charles G.
1987-01-01
The watersheds studied include mined and reclaimed; mined and unreclaimed; and unmined, agricultural land uses, and are each < 3 sq mi in area. Surface water, groundwater, and meteorologic data for the 1981 and 1982 water years were used to describe and compare hydrologic systems of the six watersheds and to identify hydrologic effects of mining and reclamation. Peak discharges were greater at the agricultural watersheds than at the unreclaimed watersheds, primarily because of large final-cut lakes in the unreclaimed watersheds. Annual runoff was greatest at the unreclaimed watersheds, intermediate at the agricultural watersheds, and least at the reclaimed watersheds. Hydrologic effects of mining were identified by comparing the hydrologic systems at mined and unreclaimed watersheds with those at unmined, agricultural watersheds. Comparisons of the hydrologic systems of these watersheds indicate that surface coal mining without reclamation has the potential to increase annual runoff, base flow, and groundwater recharge to the bedrock; reduce peak flow rates and variation in flow; lower the water table in upland areas; change the relation between surface water and groundwater divides; and create numerous, local flow systems in the shallow groundwater. Hydrologic effects of reclamation were identified by comparing the hydrologic systems at mined and reclaimed watersheds with those at mined and unreclaimed watersheds. Reclamation has the potential to decrease annual runoff, base flow, and recharge to the bedrock; increase peak flow rates, variation in flow, and response to thunderstorms; reestablish the premining relation between surface and groundwater divides; and create fewer local flow systems in the shallow groundwater. (Lantz-PTT)
Sunohara, M D; Gottschall, N; Wilkes, G; Craiovan, E; Topp, E; Que, Z; Seidou, O; Frey, S K; Lapen, D R
2015-09-01
Controlled tile drainage (CTD) regulates water and nutrient export from tile drainage systems. Observations of the effects of CTD imposed en masse at watershed scales are needed to determine the effect on downstream receptors. A paired-watershed approach was used to evaluate the effect of field-to-field CTD at the watershed scale on fluxes and flow-weighted mean concentrations (FWMCs) of N and P during multiple growing seasons. One watershed (467-ha catchment area) was under CTD management (treatment [CTD] watershed); the other (250-ha catchment area) had freely draining or uncontrolled tile drainage (UCTD) (reference [UCTD] watershed). The paired agricultural watersheds are located in eastern Ontario, Canada. Analysis of covariance and paired tests were used to assess daily fluxes and FWMCs during a calibration period when CTD intervention on the treatment watershed was minimal (2005-2006, when only 4-10% of the tile-drained area was under CTD) and a treatment period when the treatment (CTD) watershed had prolific CTD intervention (2007-2011 when 82% of tile drained fields were controlled, occupying >70% of catchment area). Significant linear regression slope changes assessed using ANCOVA ( ≤ 0.1) for daily fluxes from upstream and downstream monitoring sites pooled by calibration and treatment period were -0.06 and -0.20 (stream water) (negative values represent flux declines in CTD watershed), -0.59 and -0.77 (NH-N), -0.14 and -0.15 (NO-N), -1.77 and -2.10 (dissolved reactive P), and -0.28 and 0.45 (total P). Total P results for one site comparison contrasted with other findings likely due to unknown in-stream processes affecting total P loading, not efficacy of CTD. The FWMC results were mixed and inconclusive but suggest physical abatement by CTD is the means by which nutrient fluxes are predominantly reduced at these scales. Overall, our study results indicate that CTD is an effective practice for reducing watershed scale fluxes of stream water, N, and P during the growing season. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
1980-12-01
direction w~ih: A HE M a 6 peak dicg cft I pows TONAWANDA CREEK WATERSHED. NEW YORK MARCH 1960 FLOODED AREAS* FLOODLANO IN THE CITY OF BATAVIA AND...AREA CURVES4: 7 Uas. Aitem teivals~ DISuICT. UWFALO 00 200 DRAINIAGE AREA INf SQ. /IILES PLATE AMl V......... . u;t 99,li:k- - - - %;: :.z...NY State Geological Assn., p. 116. Grossman, William L., 1938, Geology of the Caledonia Quadrangle, M. A. Thesis University of Rochester. Kindle, E. M
Watershed erosion modeling using the probability of sediment connectivity in a gently rolling system
NASA Astrophysics Data System (ADS)
Mahoney, David Tyler; Fox, James Forrest; Al Aamery, Nabil
2018-06-01
Sediment connectivity has been shown in recent years to explain how the watershed configuration controls sediment transport. However, we find no studies develop a watershed erosion modeling framework based on sediment connectivity, and few, if any, studies have quantified sediment connectivity for gently rolling systems. We develop a new predictive sediment connectivity model that relies on the intersecting probabilities for sediment supply, detachment, transport, and buffers to sediment transport, which is integrated in a watershed erosion model framework. The model predicts sediment flux temporally and spatially across a watershed using field reconnaissance results, a high-resolution digital elevation models, a hydrologic model, and shear-based erosion formulae. Model results validate the capability of the model to predict erosion pathways causing sediment connectivity. More notably, disconnectivity dominates the gently rolling watershed across all morphologic levels of the uplands, including, microtopography from low energy undulating surfaces across the landscape, swales and gullies only active in the highest events, karst sinkholes that disconnect drainage areas, and floodplains that de-couple the hillslopes from the stream corridor. Results show that sediment connectivity is predicted for about 2% or more the watershed's area 37 days of the year, with the remaining days showing very little or no connectivity. Only 12.8 ± 0.7% of the gently rolling watershed shows sediment connectivity on the wettest day of the study year. Results also highlight the importance of urban/suburban sediment pathways in gently rolling watersheds, and dynamic and longitudinal distributions of sediment connectivity might be further investigated in future work. We suggest the method herein provides the modeler with an added tool to account for sediment transport criteria and has the potential to reduce computational costs in watershed erosion modeling.
Assessment of soil erosion risk in Komering watershed, South Sumatera, using SWAT model
NASA Astrophysics Data System (ADS)
Salsabilla, A.; Kusratmoko, E.
2017-07-01
Changes in land use watershed led to environmental degradation. Estimated loss of soil erosion is often difficult due to some factors such as topography, land use, climate and human activities. This study aims to predict soil erosion hazard and sediment yield using the Soil and Water Assessment Tools (SWAT) hydrological model. The SWAT was chosen because it can simulate the model with limited data. The study area is Komering watershed (806,001 Ha) in South Sumatera Province. There are two factors land management intervention: 1) land with agriculture, and 2) land with cultivation. These factors selected in accordance with the regulations of spatial plan area. Application of the SWAT demonstrated that the model can predict surface runoff, soil erosion loss and sediment yield. The erosion risk for each watershed can be classified and predicted its changes based on the scenarios which arranged. In this paper, we also discussed the relationship between the distribution of erosion risk and watershed's characteristics in a spatial perspective.
Liu, Yaoze; Engel, Bernard A; Collingsworth, Paris D; Pijanowski, Bryan C
2017-12-01
Nutrient loading from the Maumee River watershed is a significant reason for the harmful algal blooms (HABs) problem in Lake Erie. The nutrient loading from urban areas needs to be reduced with the installation of green infrastructure (GI) practices. The Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model was used to explore the influences of land use (LU) and climate change on water quantity and quality in Spy Run Creek watershed (SRCW) (part of Maumee River watershed), decide whether and where excess phosphorus loading existed, identify critical areas to understand where the greatest amount of runoff/pollutants originated, and optimally implement GI practices to obtain maximum environmental benefits with the lowest costs. Both LU/climate changes increased runoff/pollutants generated from the watershed. Areas with the highest runoff/pollutant amount per area, or critical areas, differed for various environmental concerns, land uses (LUs), and climates. Compared to optimization considering all areas, optimization conducted only in critical areas can provide similar cost-effective results with decreased computational time for low levels of runoff/pollutant reductions, but critical area optimization results were not as cost-effective for higher levels of runoff/pollutant reductions. Runoff/pollutants for 2011/2050 LUs/climates could be reduced to amounts of 2001 LU/climate by installation of GI practices with annual expenditures of $0.34 to $2.05 million. The optimization scenarios that were able to obtain the 2001 runoff level in 2011/2050, can also reduce all pollutants to 2001 levels in this watershed. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Saxe, Samuel; Hogue, Terri S.; Hay, Lauren
2018-02-01
This research investigates the impact of wildfires on watershed flow regimes, specifically focusing on evaluation of fire events within specified hydroclimatic regions in the western United States, and evaluating the impact of climate and geophysical variables on response. Eighty-two watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. Percent change in annual runoff ratio, low flows, high flows, peak flows, number of zero flow days, baseflow index, and Richards-Baker flashiness index were calculated for each watershed using pre- and post-fire periods. Independent variables were identified for each watershed and fire event, including topographic, vegetation, climate, burn severity, percent area burned, and soils data. Results show that low flows, high flows, and peak flows increase in the first 2 years following a wildfire and decrease over time. Relative response was used to scale response variables with the respective percent area of watershed burned in order to compare regional differences in watershed response. To account for variability in precipitation events, runoff ratio was used to compare runoff directly to PRISM precipitation estimates. To account for regional differences in climate patterns, watersheds were divided into nine regions, or clusters, through k-means clustering using climate data, and regression models were produced for watersheds grouped by total area burned. Watersheds in Cluster 9 (eastern California, western Nevada, Oregon) demonstrate a small negative response to observed flow regimes after fire. Cluster 8 watersheds (coastal California) display the greatest flow responses, typically within the first year following wildfire. Most other watersheds show a positive mean relative response. In addition, simple regression models show low correlation between percent watershed burned and streamflow response, implying that other watershed factors strongly influence response. Spearman correlation identified NDVI, aridity index, percent of a watershed's precipitation that falls as rain, and slope as being positively correlated with post-fire streamflow response. This metric also suggested a negative correlation between response and the soil erodibility factor, watershed area, and percent low burn severity. Regression models identified only moderate burn severity and watershed area as being consistently positively/negatively correlated, respectively, with response. The random forest model identified only slope and percent area burned as significant watershed parameters controlling response. Results will help inform post-fire runoff management decisions by helping to identify expected changes to flow regimes, as well as facilitate parameterization for model application in burned watersheds.
NASA Technical Reports Server (NTRS)
Brown, D.; Skaggs, R.
1975-01-01
Development of low lying southeastern shore of Pike Lake is described as part of the Rice Creek watershed study. Several small wetlands in Arden Hills, Minnesota were incorporated into the drainage plans as pollutant and nutrient sinks rather than being infilled. Lake water quality in the St. Paul-Minneapolis metropolitan area was analyzed using Landsat images. In the same urban area, the inventory and seasonal change of the open water were also studied.
Stream carbon dynamics in low-gradient headwaters of a forested watershed
April Bryant-Mason; Y. Jun Xu; Johnny M. Grace
2013-01-01
Headwater streams drain more than 70 percent of the total watershed area in the United States. Understanding of carbon dynamics in the headwater systems is of particular relevance for developing best silvicultural practices to reduce carbon export. This study was conducted in a low-gradient, predominantly forested watershed located in the Gulf Coastal Plain region, to...
Katherine J. Elliott; Lindsay R. Boring; Wayne T. Swank
2002-01-01
In 1975, we initiated a long-term interdisciplinary study of forest watershed ecosystem response to clear- cutting and cable logging in watershed 7 at the Coweeta Hydrologic Laboratory in the southern Appalachian Mountains of North Carolina. This paper describes ~20 years of change in species composition, aboveground biomass, leaf area index (LAI),...
Little Cypress Creek study: A watershed restoration option for protection of wetlands
Lisa Gandy; Randy Roberson; Tom Foti
2000-01-01
The Little Cypress Creek watershed, which is the home of the Louisiana Purchase Historic State Park and Natural Area, is one of the only remaining examples of a headwater swamp ecosystem left in Arkansas. An increase in water elevations and a change in species composition were noticed in the park in late 1970. A study of the upper watershed of Little Cypress Creek was...
Using four capitals to assess watershed sustainability.
Pérez-Maqueo, Octavio; Martinez, M Luisa; Vázquez, Gabriela; Equihua, Miguel
2013-03-01
The La Antigua watershed drains into the Gulf of Mexico and can be considered as one of the most important areas in Mexico because of its high productivity, history, and biodiversity, although poverty remains high in the area in spite of these positive attributes. In this study, we performed an integrated assessment of the watershed to recommend a better direction toward a sustainable management in which the four capitals (natural, human, social, and built) are balanced. We contrasted these four capitals in the municipalities of the upper, middle and lower watershed and found that natural capital (natural ecosystems and ecosystem services) was higher in the upper and middle watershed, while human and social capitals (literacy, health, education and income) were generally higher downstream. Overall, Human Development Index was negatively correlated with the percentage of natural ecosystems in the watershed, especially in the upper and lower watershed regions. Our results indicate that natural capital must be fully considered in projections for increasing human development, so that natural resources can be preserved and managed adequately while sustaining intergenerational well-being.
Using Four Capitals to Assess Watershed Sustainability
NASA Astrophysics Data System (ADS)
Pérez-Maqueo, Octavio; Martinez, M. Luisa; Vázquez, Gabriela; Equihua, Miguel
2013-03-01
The La Antigua watershed drains into the Gulf of Mexico and can be considered as one of the most important areas in Mexico because of its high productivity, history, and biodiversity, although poverty remains high in the area in spite of these positive attributes. In this study, we performed an integrated assessment of the watershed to recommend a better direction toward a sustainable management in which the four capitals (natural, human, social, and built) are balanced. We contrasted these four capitals in the municipalities of the upper, middle and lower watershed and found that natural capital (natural ecosystems and ecosystem services) was higher in the upper and middle watershed, while human and social capitals (literacy, health, education and income) were generally higher downstream. Overall, Human Development Index was negatively correlated with the percentage of natural ecosystems in the watershed, especially in the upper and lower watershed regions. Our results indicate that natural capital must be fully considered in projections for increasing human development, so that natural resources can be preserved and managed adequately while sustaining intergenerational well-being.
Kirsten Gallo; Steven H. Lanigan; Peter Eldred; Sean N. Gordon; Chris Moyer
2005-01-01
We aggregated road, vegetation, and inchannel data to assess the condition of sixth-field watersheds and describe the distribution of the condition of watersheds in the Northwest Forest Plan (the Plan) area. The assessment is based on 250 watersheds selected at random within the Plan area. The distributions of conditions are presented for watersheds and for many of the...
Protect and Restore Mill Creek Watershed; Annual Report 2002-2003.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2004-01-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Mill Creek watershed are coordinated with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. During the FY 2002, trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-streammore » crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed. Maintenance to the previously built fence was also completed.« less
Land cover change impact on urban flood modeling (case study: Upper Citarum watershed)
NASA Astrophysics Data System (ADS)
Siregar, R. I.
2018-03-01
The upper Citarum River watershed utilizes remote sensing technology in Geographic Information System to provide information on land coverage by interpretation of objects in the image. Rivers that pass through urban areas will cause flooding problems causing disadvantages, and it disrupts community activities in the urban area. Increased development in a city is related to an increase in the number of population growth that added by increasing quality and quantity of life necessities. Improved urban lifestyle changes have an impact on land cover. The impact in over time will be difficult to control. This study aims to analyze the condition of flooding in urban areas caused by upper Citarum watershed land-use change in 2001 with the land cover change in 2010. This modeling analyzes with the help of HEC-RAS to describe flooded inundation urban areas. Land cover change in upper Citarum watershed is not very significant; it based on the results of data processing of land cover has the difference of area that changed is not enormous. Land cover changes for the floods increased dramatically to a flow coefficient for 2001 is 0.65 and in 2010 at 0.69. In 2001, the inundation area about 105,468 hectares and it were about 92,289 hectares in 2010.
Hydrologic Effects of Brush Management in Central Texas
NASA Astrophysics Data System (ADS)
Banta, J. R.; Slattery, R.
2011-12-01
Encroachment of woody vegetation into traditional savanna grassland ecosystems in central Texas has largely been attributed to land use practices of settlers, most notably overgrazing and fire suppression. Implementing brush management practices (removing the woody vegetation and allowing native grasses to reestablish in the area), could potentially change the hydrology in a watershed. The U.S. Geological Survey, in cooperation with several local, State, and Federal cooperators, studied the hydrologic effects of ashe juniper (Juniperus ashei) removal as a brush management conservation practice in the Honey Creek State Natural Area in Comal County, Tex. Two adjacent watersheds of 104 and 159 hectares were used in a paired study. Rainfall, streamflow, evapotranspiration (Bowen ratio method), and water quality data were collected in both watersheds. Using a hydrologic mass balance approach, rainfall was allocated to surface-water runoff, evapotranspiration, and groundwater recharge. Groundwater recharge was not directly measured, but estimated as the residual of the hydrologic mass balance. After hydrologic data were collected in both watersheds for 3 years, approximately 80 percent of the woody vegetation (ashe juniper) was selectively removed from the 159 hectare watershed (treatment watershed). Brush management was not implemented in the other (reference) watershed. Hydrologic data were collected in both watersheds for six years after brush management implementation. The resulting data were examined for differences in the hydrologic budget between the reference and treatment watersheds as well as between pre- and post-brush management periods to assess effects of the treatment. Preliminary results indicate there are differences in the hydrologic budget as well as water quality between the watersheds during pre- and post-treatment periods.
Perakis, S.S.; Hedin, L.O.
2007-01-01
We sampled 100 unpolluted, old-growth forested watersheds, divided among 13 separate study areas over 5 years in temperate southern Chile and Argentina, to evaluate relationships among dominant soil-forming state factors and dissolved carbon and nitrogen concentrations in watershed streams. These watersheds provide a unique opportunity to examine broad-scale controls over carbon (C) and nitrogen (N) biogeochemistry in the absence of significant human disturbance from chronic N deposition and land use change. Variations in the ratio dissolved organic carbon (DOC) to nitrogen (DON) in watershed streams differed by underlying soil parent material, with average C:N = 29 for watersheds underlain by volcanic ash and basalt versus C:N = 73 for sedimentary and metamorphic parent materials, consistent with stronger adsorption of low C:N hydrophobic materials by amorphous clays commonly associated with volcanic ash and basalt weathering. Mean annual precipitation was related positively to variations in both DOC (range: 0.2-9.7 mg C/L) and DON (range: 0.008-0.135 mg N/L) across study areas, suggesting that variations in water volume and concentration may act synergistically to influence C and N losses across dry to wet gradients in these forest ecosystems. Dominance of vegetation by broadleaf versus coniferous trees had negligible effects on organic C and N concentrations in comparison to abiotic factors. We conclude that precipitation volume and soil parent material are important controls over chemical losses of dissolved organic C and N from unpolluted temperate forest watersheds. Our results raise the possibility that biotic imprints on watershed C and N losses may be less pronounced in naturally N-poor forests than in areas impacted by land use change and chronic N deposition. Copyright 2007 by the American Geophysical Union.
Sediment yields from small, steep coastal watersheds of California
Warrick, Jonathan A.; Melack, John M.; Goodridge, Blair M.
2015-01-01
Global inventories of sediment discharge to the ocean highlight the importance of small, steep watersheds (i.e., those having drainage areas less than 100,000 km2 and over 1000 m of relief) that collectively provide a dominant flux of sediment. The smallest of these coastal watersheds (e.g., those that have drainage areas less than 1000 km2) can represent a large portion of the drainage areas of active margin coasts, such as California’s coast, but remain almost universally unmonitored. Here we report on the suspended-sediment discharge of several small coastal watersheds (10-56 km2) of the Santa Ynez Mountains, California, that were found to have ephemeral discharge and suspended-sediment concentrations ranging between 1 and over 200,000 mgL-1. Sediment concentrations were weakly correlated with discharge (r2 = 0.10–0.25), and all types of hysteresis patterns were observed during high flows (clockwise, counterclockwise, no hysteresis, and complex). Sediment discharge varied strongly with time and was measurably elevated in one watershed following a wildfire. Although sediment yields varied by over 100-fold across the watersheds (e.g., 15 – 2100 tkm-2 yr -1during the relatively wet 2005 water year), the majority of sediment discharge (65-80%) occurred during only 1% of the time for all watersheds. Furthermore, sampling of dozens of high flow events provides evidence that sediment yields were generally related to peak discharge yields, although these relationships were not consistent across the watersheds. These results suggest that small watersheds of active margins can provide large fluxes of sediment to the coast, but that the rates and timing of this sediment discharge is more irregular in time – and thus more difficult to characterize – than the better monitored and studied watersheds that are 1000-100,000 km2.
NASA Astrophysics Data System (ADS)
Soni, Sandeep
2017-09-01
The quantitative analysis of the watershed is important for the quantification of the channel network and to understand its geo-hydrological behaviour. Assessment of drainage network and their relative parameters have been quantitatively carried out for the Chakrar watershed of Madhya Pradesh, India, to understand the prevailing geological variation, topographic information and structural setup of the watershed and their interrelationship. Remote Sensing and Geographical Information System (GIS) has been used for the delineation and calculation of the morphometric parameters of the watershed. The Chakrar watershed is sprawled over an area of 415 km2 with dendritic, parallel and trellis drainage pattern. It is sub-divided into nine sub-watersheds. The study area is designated as sixth-order basin and lower and middle order streams mostly dominate the basin with the drainage density value of 2.46 km/km2 which exhibits gentle to steep slope terrain, medium dense vegetation, and less permeable with medium precipitation. The mean bifurcation value of the basin is 4.16 and value of nine sub-watersheds varies from 2.83 to 4.44 which reveals drainage networks formed on homogeneous rocks when the influences of geologic structures on the stream network is negligible. Form factor, circularity ratio and elongation ratio indicate an elongated basin shape having less prone to flood, lower erosion and sediment transport capacities. The results from the morphometric assessment of the watershed are important in water resources evaluation and its management and for the selection of recharge structure in the area for future water management.
NASA Astrophysics Data System (ADS)
Papelis, C.; Williams, A. C.; Boettcher, T. M.
2008-12-01
Metals, metalloids, and nutrients are common contaminants of concern in arid and semi-arid watersheds in the Southwestern U.S. Because of the dramatic population growth in this part of the U.S., the potential for contamination of urban watersheds has also increased over the last few decades. Streams in urban watersheds receive storm water, urban runoff, shallow groundwater, and treated wastewater, among other sources. In addition, urban watersheds are often heavily managed to mitigate flood events and sediment- related impacts. Sediment transport can have a profound effect on the water quality of affected bodies of water. However, differences in geology, hydrogeology, and land use may have dramatic effects on the distribution of nutrients and metals in different urban watersheds. To test these effects, aqueous and sediment samples were collected above and below erosion control and other structures along two heavily managed urban watersheds, namely the Las Vegas Wash in the Las Vegas Valley Watershed, Nevada, and the Rio Salado (Salt River) in the Phoenix Metropolitan Area, Arizona. The construction of such control structures has the potential to alter the distribution of metals and metalloids in bodies of water used by wildlife. In this study, all sediments were characterized by particle size distribution, specific surface area, mineralogical composition, and scanning electron microscopy. The results of total arsenic, boron, and phosphorus extractions will be discussed, as a function of sediment characteristics. Significant differences exist between the two U.S. Southwest watersheds studied, including land use, water sources, sediment characteristics, nutrient and metal distribution, and overall system complexity. These differences lead to significant variations in metalloid and nutrient distributions in the two watersheds. Differences and similarities in the two systems will be explained as a function of sediment characteristics and watershed properties.
Modelling land use/cover changes with markov-cellular automata in Komering Watershed, South Sumatera
NASA Astrophysics Data System (ADS)
Kusratmoko, E.; Albertus, S. D. Y.; Supriatna
2017-01-01
This research has a purpose to study and develop a model that can representing and simulating spatial distribution pattern of land use change in Komering watershed. The Komering watershed is one of nine sub Musi river basin and is located in the southern part of Sumatra island that has an area of 8060,62 km2. Land use change simulations, achieved through Markov-cellular automata (CA) methodologies. Slope, elevation, distance from road, distance from river, distance from capital sub-district, distance from settlement area area were driving factors that used in this research. Land use prediction result in 2030 also shows decrease of forest acreage up to -3.37%, agricultural land decreased up to -2.13%, and open land decreased up to -0.13%. On the other hand settlement area increased up to 0.07%, and plantation land increased up to 5.56%. Based on the predictive result, land use unconformity percentage to RTRW in Komering watershed is 18.62 % and land use conformity is 58.27%. Based on the results of the scenario, where forest in protected areas and agriculture land are maintained, shows increase the land use conformity amounted to 60.41 % and reduce unconformity that occur in Komering watershed to 17.23 %.
Carvin, Rebecca; Good, Laura W.; Fitzpatrick, Faith A.; Diehl, Curt; Songer, Katherine; Meyer, Kimberly J.; Panuska, John C.; Richter, Steve; Whalley, Kyle
2018-01-01
This study tested a focused strategy for reducing phosphorus (P) and sediment loads in agricultural streams. The strategy involved selecting small watersheds identified as likely to respond relatively quickly, and then focusing conservation practices on high-contributing fields within those watersheds. Two 5,000 ha (12,360 ac) watersheds in the Driftless Area of south central Wisconsin, previously ranked in the top 6% of similarly sized Wisconsin watersheds for expected responsiveness to conservation efforts to reduce high P and sediment loads, were chosen for the study. The stream outlets from both watersheds were monitored from October of 2006 through September of 2016 for streamflow and concentrations of sediment, total P, and, beginning in October of 2009, total dissolved P. Fields and pastures having the highest potential P delivery to the streams in each watershed were identified using the Wisconsin P Index (Good et al. 2012). After three years of baseline monitoring (2006 to 2009), farmers implemented both field- and farm-based conservation practices in one watershed (treatment) as a means to reduce sediment and P inputs to the stream from the highest contributing areas, whereas there were no out-of-the-ordinary conservation efforts in the second watershed (control). Implementation occurred primarily in 2011 and 2012. In the four years following implementation of conservation practices (2013 through 2016), there was a statistically significant reduction in storm-event suspended sediment loads in the treatment watershed compared to the control watershed when the ground was not frozen (p = 0.047). While there was an apparent reduction in year-round suspended sediment event loads, it was not statistically significant at the 95% confidence level (p = 0.15). Total P loads were significantly reduced for runoff events (p < 0.01) with a median reduction of 50%. Total P and total dissolved P concentrations for low-flow conditions were also significantly reduced (p < 0.01) compared to the control watershed. This study demonstrated that a strategy that first identifies watersheds likely to respond to conservation efforts and then focuses implementation on relatively high-contributing fields within those watersheds can be successful in reducing stream P concentrations and loads.
Climate change and the water cycle in newly irrigated areas.
Abrahão, Raphael; García-Garizábal, Iker; Merchán, Daniel; Causapé, Jesús
2015-02-01
Climate change is affecting agriculture doubly: evapotranspiration is increasing due to increments in temperature while the availability of water resources is decreasing. Furthermore, irrigated areas are expanding worldwide. In this study, the dynamics of climate change impacts on the water cycle of a newly irrigated watershed are studied through the calculation of soil water balances. The study area was a 752-ha watershed located on the left side of the Ebro river valley, in Northeast Spain. The soil water balance procedures were carried out throughout 1827 consecutive days (5 years) of hydrological and agronomical monitoring in the study area. Daily data from two agroclimatic stations were used as well. Evaluation of the impact of climate change on the water cycle considered the creation of two future climate scenarios for comparison: 2070 decade with climate change and 2070 decade without climate change. The main indicators studied were precipitation, irrigation, reference evapotranspiration, actual evapotranspiration, drainage from the watershed, and irrigation losses. The aridity index was also applied. The results represent a baseline scenario in which adaptation measures may be included and tested to reduce the impacts of climate change in the studied area and other similar areas.
Wemple, B.; Shanley, J.; Denner, J.; Ross, D.; Mills, K.
2007-01-01
Mountain regions throughout the world face intense development pressures associated with recreational and tourism uses. Despite these pressures, much of the research on bio-geophysical impacts of humans in mountain regions has focused on the effects of natural resource extraction. This paper describes findings from the first 3 years of a study examining high elevation watershed processes in a region undergoing alpine resort development. Our study is designed as a paired-watershed experiment. The Ranch Brook watershed (9.6 km2) is a relatively pristine, forested watershed and serves as the undeveloped 'control' basin. West Branch (11.7 km2) encompasses an existing alpine ski resort, with approximately 17% of the basin occupied by ski trails and impervious surfaces, and an additional 7% slated for clearing and development. Here, we report results for water years 2001-2003 of streamflow and water quality dynamics for these watersheds. Precipitation increases significantly with elevation in the watersheds, and winter precipitation represents 36-46% of annual precipitation. Artificial snowmaking from water within West Branch watershed currently augments annual precipitation by only 3-4%. Water yield in the developed basin exceeded that in the control by 18-36%. Suspended sediment yield was more than two and a half times greater and fluxes of all major solutes were higher in the developed basin. Our study is the first to document the effects of existing ski area development on hydrology and water quality in the northeastern US and will serve as an important baseline for evaluating the effects of planned resort expansion activities in this area.
Liu, Peilong; Hao, Lu; Pan, Cen; Zhou, Decheng; Liu, Yongqiang; Sun, Ge
2017-07-01
Leaf area index (LAI) is a key parameter to characterize vegetation dynamics and ecosystem structure that determines the ecosystem functions and services such as clean water supply and carbon sequestration in a watershed. However, linking LAI dynamics and environmental controls (i.e., coupling biosphere, atmosphere, and anthroposphere) remains challenging and such type of studies have rarely been done at a watershed scale due to data availability. The present study examined the spatial and temporal variations of LAI for five ecosystem types within a watershed with a complex topography in the Upper Heihe River Basin, a major inland river in the arid and semi-arid western China. We integrated remote sensing-based GLASS (Global Land Surface Satellite) LAI products, interpolated climate data, watershed characteristics, and land management records for the period of 2001-2012. We determined the relationships among LAI, topography, air temperature and precipitation, and grazing history by five ecosystem types using several advanced statistical methods. We show that long-term mean LAI distribution had an obvious vertical pattern as controlled by precipitation and temperature in a hilly watershed. Overall, watershed-wide mean LAI had an increasing trend overtime for all ecosystem types during 2001-2012, presumably as a result of global warming and a wetting climate. However, the fluctuations of observed LAI at a pixel scale (1km) varied greatly across the watershed. We classified the vegetation changes within the watershed as 'Improved', 'Stabilized', and 'Degraded' according their respective LAI changes. We found that climate was not the only driver for temporal vegetation changes for all land cover types. Grazing partially contributed to the decline of LAI in some areas and masked the positive climate warming effects in other areas. Extreme weathers such as cold spells and droughts could substantially affect inter-annual variability of LAI dynamics. We concluded that temporal and spatial LAI dynamics were rather complex and were affected by both climate variations and human disturbances in the study basin. Future monitoring studies should focus on the functional interactions among vegetation dynamics, climate variations, land management, and human disturbances. Published by Elsevier B.V.
An assessment of the effects of cell size on AGNPS modeling of watershed runoff
Wu, S.-S.; Usery, E.L.; Finn, M.P.; Bosch, D.D.
2008-01-01
This study investigates the changes in simulated watershed runoff from the Agricultural NonPoint Source (AGNPS) pollution model as a function of model input cell size resolution for eight different cell sizes (30 m, 60 m, 120 m, 210 m, 240 m, 480 m, 960 m, and 1920 m) for the Little River Watershed (Georgia, USA). Overland cell runoff (area-weighted cell runoff), total runoff volume, clustering statistics, and hot spot patterns were examined for the different cell sizes and trends identified. Total runoff volumes decreased with increasing cell size. Using data sets of 210-m cell size or smaller in conjunction with a representative watershed boundary allows one to model the runoff volumes within 0.2 percent accuracy. The runoff clustering statistics decrease with increasing cell size; a cell size of 960 m or smaller is necessary to indicate significant high-runoff clustering. Runoff hot spot areas have a decreasing trend with increasing cell size; a cell size of 240 m or smaller is required to detect important hot spots. Conclusions regarding cell size effects on runoff estimation cannot be applied to local watershed areas due to the inconsistent changes of runoff volume with cell size; but, optimal cells sizes for clustering and hot spot analyses are applicable to local watershed areas due to the consistent trends.
Steuer, Jeffrey J.
2010-01-01
It is widely recognized that urbanization can affect ecological conditions in aquatic systems; numerous studies have identified impervious surface cover as an indicator of urban intensity and as an index of development at the watershed, regional, and national scale. Watershed percent imperviousness, a commonly understood urban metric was used as the basis for a generalized watershed disturbance metric that, when applied in conjunction with weighted percent agriculture and percent grassland, predicted stream biotic conditions based on Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness across a wide range of environmental settings. Data were collected in streams that encompassed a wide range of watershed area (4.4-1,714 km), precipitation (38-204 cm/yr), and elevation (31-2,024 m) conditions. Nevertheless the simple 3-landcover disturbance metric accounted for 58% of the variability in EPT richness based on the 261 nationwide sites. On the metropolitan area scale, relationship r ranged from 0.04 to 0.74. At disturbance values 15. Future work may incorporate watershed management practices within the disturbance metric, further increasing the management applicability of the relation. Such relations developed on a regional or metropolitan area scale are likely to be stronger than geographically generalized models; as found in these EPT richness relations. However, broad spatial models are able to provide much needed understanding in unmonitored areas and provide initial guidance for stream potential.
NASA Astrophysics Data System (ADS)
Musgrove, M.; Stern, L. A.; Banner, J. L.
2010-06-01
SummaryA two and a half year study of two adjacent watersheds at the Honey Creek State Natural Area (HCSNA) in central Texas was undertaken to evaluate spatial and temporal variations in springwater geochemistry, geochemical evolution processes, and potential effects of brush control on karst watershed hydrology. The watersheds are geologically and geomorphologically similar, and each has springs discharging into Honey Creek, a tributary to the Guadalupe River. Springwater geochemistry is considered in a regional context of aquifer components including soil water, cave dripwater, springwater, and phreatic groundwater. Isotopic and trace element variability allows us to identify both vadose and phreatic groundwater contributions to surface water in Honey Creek. Spatial and temporal geochemical data for six springs reveal systematic differences between the two watersheds. Springwater Sr isotope values lie between values for the limestone bedrock and soils at HCSNA, reflecting a balance between these two primary sources of Sr. Sr isotope values for springs within each watershed are consistent with differences between soil compositions. At some of the springs, consistent temporal variability in springwater geochemistry (Sr isotopes, Mg/Ca, and Sr/Ca values) appears to reflect changes in climatic and hydrologic parameters (rainfall/recharge) that affect watershed processes. Springwater geochemistry was unaffected by brush removal at the scale of the HCSNA study. Results of this study build on previous regional studies to provide insight into watershed hydrology and regional hydrologic processes, including connections between surface water, vadose groundwater, and phreatic groundwater.
Restore McComas Watershed; Meadow Creek Watershed, 2002-2003 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2004-01-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing. During years 2000-2003, trees were planted in riparian areas within the meadow and its tributaries. Culverts have been prioritized for replacement to accommodate fish passage throughoutmore » the watershed. Designs for replacement are being coordinated with the Nez Perce National Forest. Twenty miles of road were contracted for decommissioning. Tribal crews completed maintenance to the previously built fence.« less
Effect of Watershed Cover on Overland Flow from a Major Storm in Southwestern Wisconsin
Richard S. Sartz
1969-01-01
A runoff study in the Driftless Area showed that both total flow and peak rate of flow from a 3-hour, 4-inch rain were strongly affected by the watershed cover. Peak flows ranged from 2.42 inches per hour for alfalfa meadow to 0.010 inch per hour for undisturbed forested watersheds was surprisingly similar.
Agro-hydrologic landscapes in the Upper Mississippi and Ohio River basins.
Schilling, Keith E; Wolter, Calvin F; McLellan, Eileen
2015-03-01
A critical part of increasing conservation effectiveness is targeting the "right practice" to the "right place" where it can intercept pollutant flowpaths. Conceptually, these flowpaths can be inferred from soil and slope characteristics, and in this study, we developed an agro-hydrologic classification to identify N and P loss pathways and priority conservation practices in small watersheds in the U.S. Midwest. We developed a GIS framework to classify 11,010 small watersheds in the Upper Mississippi and Ohio River basins based on soil permeability and slope characteristics of agricultural cropland areas in each watershed. The amount of cropland in any given watershed varied from <10 to >60 %. Cropland areas were classified into five main categories, with slope classes of <2, 2-5, and >5 %, and soil drainage classes of poorly and well drained. Watersheds in the Upper Mississippi River basin (UMRB) were dominated by cropland areas in low slopes and poorly drained soils, whereas less-intensively cropped watersheds in Wisconsin and Minnesota (in the UMRB) and throughout the Ohio River basin were overwhelmingly well drained. Hydrologic differences in cropped systems indicate that a one-size-fits-all approach to conservation selection will not work. Consulting the classification scheme proposed herein may be an appropriate first-step in identifying those conservation practices that might be most appropriate for small watersheds in the basin.
Prioritization of catchments based on soil erosion using remote sensing and GIS.
Khadse, Gajanan K; Vijay, Ritesh; Labhasetwar, Pawan K
2015-06-01
Water and soil are the most essential natural resources for socioeconomic development and sustenance of life. A study of soil and water dynamics at a watershed level facilitates a scientific approach towards their conservation and management. Remote sensing and Geographic Information System are tools that help to plan and manage natural resources on watershed basis. Studies were conducted for the formulation of catchment area treatment plan based on watershed prioritization with soil erosion studies using remote sensing techniques, corroborated with Geographic Information System (GIS), secondary data and ground truth information. Estimation of runoff and sediment yield is necessary in prioritization of catchment for the design of soil conservation structures and for identifying the critical erosion-prone areas of a catchment for implementation of best management plan with limited resources. The Universal Soil Loss Equation, Sediment Yield Determination and silt yield index methods are used for runoff and soil loss estimation for prioritization of the catchments. On the basis of soil erosion classes, the watersheds were grouped into very high, high, moderate and low priorities. High-priority watersheds need immediate attention for soil and water conservation, whereas low-priority watershed having good vegetative cover and low silt yield index may not need immediate attention for such treatments.
NASA Astrophysics Data System (ADS)
Bitew, M. M.; Goodrich, D. C.; Demaria, E.; Heilman, P.; Kautz, M. A.
2017-12-01
Walnut Gulch is a semi-arid environment experimental watershed and Long Term Agro-ecosystem Research (LTAR) site managed by USDA-ARS Southwest Watershed Research Center for which high-resolution long-term hydro-climatic data are available across its 150 km2 drainage area. In this study, we present the analysis of 50 years of continuous hourly rainfall data to evaluate runoff control and generation processes for improving the QA-QC plans of Walnut Gulch to create high-quality data set that is critical for reducing water balance uncertainties. Multiple linear regression models were developed to relate rainfall properties, runoff characteristics and watershed properties. The rainfall properties were summarized to event based total depth, maximum intensity, duration, the location of the storm center with respect to the outlet, and storm size normalized to watershed area. We evaluated the interaction between the runoff and rainfall and runoff as antecedent moisture condition (AMC), antecedent runoff condition (ARC) and, runoff depth and duration for each rainfall events. We summarized each of the watershed properties such as contributing area, slope, shape, channel length, stream density, channel flow area, and percent of the area of retention stock ponds for each of the nested catchments in Walnut Gulch. The evaluation of the model using basic and categorical statistics showed good predictive skill throughout the watersheds. The model produced correlation coefficients ranging from 0.4-0.94, Nash efficiency coefficients up to 0.77, and Kling-Gupta coefficients ranging from 0.4 to 0.98. The model predicted 92% of all runoff generations and 98% of no-runoff across all sub-watersheds in Walnut Gulch. The regression model also indicated good potential to complement the QA-QC procedures in place for Walnut Gulch dataset publications developed over the years since the 1960s through identification of inconsistencies in rainfall and runoff relations.
NASA Astrophysics Data System (ADS)
Legorreta Paulin, G.; Bursik, M. I.; Lugo Hubp, J.; Aceves Quesada, J. F.
2014-12-01
This work provides an overview of the on-going research project (Grant SEP-CONACYT # 167495) from the Institute of Geography at the National Autonomous University of Mexico (UNAM) that seeks to conduct a multi-temporal landslide inventory, analyze the distribution of landslides, and characterize landforms that are prone to slope instability by using Geographic Information Systems (GIS). The study area is the Río El Estado watershed that covers 5.2 km2 and lies on the southwestern flank of Pico de Orizaba volcano.The watershed was studied by using aerial photographs, fieldwork, and adaptation of the Landslide Hazard Zonation Protocol of the Washington State Department of Natural Resources, USA. 107 gravitational slope failures of six types were recognized: shallow landslides, debris-avalanches, deep-seated landslides, debris flows, earthflows, and rock falls. This analysis divided the watershed into 12 mass-wasting landforms on which gravitational processes occur: inner gorges, headwalls, active scarps of deep-seated landslides, meanders, plains, rockfalls, non-rule-identified inner gorges, non-rule-identified headwalls, non-rule-identified converging hillslopes and three types of hillslopes classified by their gradient: low, moderate, and high. For each landform the landslide area rate and the landslide frequency rate were calculated as well as the overall hazard rating. The slope-stability hazard rating has a range that goes from low to very high. The overall hazard rating for this watershed was very high. The shallow slide type landslide was selected and area and volume of individual landslides were retrieved from the watershed landslide inventory geo-database, to establish an empirical relationship between area and volume that takes the form of a power law. The relationship was used to estimate the total volume of landslides in the study area. The findings are important to understand the long-term evolution of the southwestern flank stream system of Pico de Orizaba, and may prove useful in the assessment of landslide susceptibility and hazard in volcanic terrains.
NASA Astrophysics Data System (ADS)
Rasoulzadeh Gharibdousti, S.; Stoecker, A.; Storm, D.
2017-12-01
One of the main causes of water quality impairment in the United States is human induced Non-Point Source (NPS) pollution through intensive agriculture. The Fort Cobb Reservoir (FCR) watershed located in west-central Oklahoma, United States is a rural agricultural catchment with known issues of NPS pollution including suspended solids, siltation, nutrients, and pesticides. Recently, several Best Management Practices (BMPs) have been implemented in the watershed (such as no-tillage and cropland to grassland conversion) to improve water quality. The objective in this study is to estimate the most cost effective selection and placement of BMPs on farmlands to mitigate soil erosion and the delivery of sediment and nutrient loads to the FCR from Five Mile Creek (FMC) area of the FCR watershed. We employed the Soil and Water Assessment Tool (SWAT) to develop the hydrological model of the study area. The watershed was delineated using the 10 m National Elevation Dataset and divided into 43 sub-basins with an average area of 8 km2. Through a combination of Soil Survey Geographic Database- SSURGO soil data, the US Department of Agriculture crop layer and the slope information, the watershed was further divided into 15,217 hydrologic response units (HRUs). The historical climate pattern in the watershed was represented by two different weather stations. The model was calibrated for the 1991 - 2000 period and validated over the 2001 - 2010 period against the monthly USGS observations of streamflow and suspended sediment concentration recorded at the watershed outlet. Model parametrization resulted in satisfactory values for the R2 (0.64, 0.35) and NS (0.61, 0.34) in calibration period and an excellent model performance (R2 = 0.79, 0.38; NS = 0.75, 0.43) in validation period for streamflow and sediment concentration respectively. We have selected 20 BMPs to estimate their efficacy in terms of water, sediment, and crop yields. Linear Programming (LP) was used to determine the cost minimizing choice of BMPs for each HRU that meets sediment and nutrient loads targets for the watershed. The model is capable of providing precise information for stakeholders to prioritize ecologically sound and economically feasible BMPs that are capable of mitigating human induced impacts at the watershed scale.
Application of SWAT and CAST model on Damma Glacier CZO
NASA Astrophysics Data System (ADS)
Andrianaki, Maria; Bernasconi, Stefano; Kobierska, Florian; Nikolaidis, Nikolaos
2014-05-01
Damma Glacier is one of the Critical Zone Observatories, located at the central Swiss Alps, Switzerland and is characterized by a 150-year soil chronosequence. In this study, we used the Soil and Water Assessment Tool (SWAT) to simulate the hydrology of the watershed of Damma glacier, Switzerland and of the extended area that feeds Goescheneralpsee and includes Damma watershed. SWAT was calibrated for the watershed of Damma glacier with the stream flow data collected between 2009 and 2011. Subsequently and in order to study the up-scalling effect, SWAT was run for the greater area using the same parameters. Carbon accumulation and aggregate formation along Damma soil chronosequence was modelled using ROTH-C and CAST models.
Evaluating the capabilities of watershed-scale models in estimating sediment yield at field-scale.
Sommerlot, Andrew R; Nejadhashemi, A Pouyan; Woznicki, Sean A; Giri, Subhasis; Prohaska, Michael D
2013-09-30
Many watershed model interfaces have been developed in recent years for predicting field-scale sediment loads. They share the goal of providing data for decisions aimed at improving watershed health and the effectiveness of water quality conservation efforts. The objectives of this study were to: 1) compare three watershed-scale models (Soil and Water Assessment Tool (SWAT), Field_SWAT, and the High Impact Targeting (HIT) model) against calibrated field-scale model (RUSLE2) in estimating sediment yield from 41 randomly selected agricultural fields within the River Raisin watershed; 2) evaluate the statistical significance among models; 3) assess the watershed models' capabilities in identifying areas of concern at the field level; 4) evaluate the reliability of the watershed-scale models for field-scale analysis. The SWAT model produced the most similar estimates to RUSLE2 by providing the closest median and the lowest absolute error in sediment yield predictions, while the HIT model estimates were the worst. Concerning statistically significant differences between models, SWAT was the only model found to be not significantly different from the calibrated RUSLE2 at α = 0.05. Meanwhile, all models were incapable of identifying priorities areas similar to the RUSLE2 model. Overall, SWAT provided the most correct estimates (51%) within the uncertainty bounds of RUSLE2 and is the most reliable among the studied models, while HIT is the least reliable. The results of this study suggest caution should be exercised when using watershed-scale models for field level decision-making, while field specific data is of paramount importance. Copyright © 2013 Elsevier Ltd. All rights reserved.
How misapplication of the hydrologic unit framework diminishes the meaning of watersheds
Omernik, James M.; Griffith, Glenn E.; Hughes, Robert M.; Glover, James B.; Weber, Marc H.
2017-01-01
Hydrologic units provide a convenient but problematic nationwide set of geographic polygons based on subjectively determined subdivisions of land surface areas at several hierarchical levels. The problem is that it is impossible to map watersheds, basins, or catchments of relatively equal size and cover the whole country. The hydrologic unit framework is in fact composed mostly of watersheds and pieces of watersheds. The pieces include units that drain to segments of streams, remnant areas, noncontributing areas, and coastal or frontal units that can include multiple watersheds draining to an ocean or large lake. Hence, half or more of the hydrologic units are not watersheds as the name of the framework “Watershed Boundary Dataset” implies. Nonetheless, hydrologic units and watersheds are commonly treated as synonymous, and this misapplication and misunderstanding can have some serious scientific and management consequences. We discuss some of the strengths and limitations of watersheds and hydrologic units as spatial frameworks. Using examples from the Northwest and Southeast United States, we explain how the misapplication of the hydrologic unit framework has altered the meaning of watersheds and can impair understanding associations between spatial geographic characteristics and surface water conditions.
Land Cover Vegetation Changes and Hydrology in Central Texas
NASA Astrophysics Data System (ADS)
Banta, J. R.; Slattery, R.
2013-12-01
Encroachment of woody vegetation into traditional savanna grassland ecosystems in central Texas has largely been attributed to land use practices of settlers, most notably overgrazing and fire suppression. Implementing changes in land cover vegetation (removing the woody vegetation and allowing native grasses to reestablish in the area, commonly referred to as brush management), could potentially change the hydrology in a watershed. The U.S. Geological Survey, in cooperation with several local, State, and Federal agencies, studied the hydrologic effects of ashe juniper (Juniperus ashei) removal as a brush management conservation practice in the Honey Creek State Natural Area in Comal County, Tex. Two adjacent watersheds of 104 and 159 hectares were used in a paired study. Rainfall, streamflow, evapotranspiration (Bowen ratio method), and water quality data were collected in both watersheds. Using a hydrologic mass balance approach, rainfall was allocated to surface-water runoff, evapotranspiration, and potential groundwater recharge. Groundwater recharge was not directly measured, but estimated as the residual of the hydrologic mass balance. After hydrologic data were collected in both watersheds for 3 years, approximately 80 percent of the woody vegetation (ashe juniper) was selectively removed from the 159 hectare watershed (treatment watershed). Brush management was not implemented in the other (reference) watershed. Hydrologic data were collected in both watersheds for six years after brush management implementation. The resulting data were examined for differences in the hydrologic budget between the reference and treatment watersheds as well as between pre- and post-brush management periods to assess effects of the treatment. Results indicate there are differences in the hydrologic budget and water quality between the reference and treatment watersheds, as well as between pre- and post-brush management periods.
Soil moisture variability over Odra watershed: Comparison between SMOS and GLDAS data
NASA Astrophysics Data System (ADS)
Zawadzki, Jaroslaw; Kędzior, Mateusz
2016-03-01
Monitoring of temporal and spatial soil moisture variability is an important issue, both from practical and scientific point of view. It is well known that passive, L-band, radiometric measurements provide best soil moisture estimates. Unfortunately as it was observed during Soil Moisture and Ocean Salinity (SMOS) mission, which was specially dedicated to measure soil moisture, these measurements suffer significant data loss. It is caused mainly by radio frequency interference (RFI) which strongly contaminates Central Europe and even in particularly unfavorable conditions, might prevent these data from being used for regional or watershed scale analysis. Nevertheless, it is highly awaited by researchers to receive statistically significant information on soil moisture over the area of a big watershed. One of such watersheds, the Odra (Oder) river watershed, lies in three European countries - Poland, Germany and the Czech Republic. The area of the Odra river watershed is equal to 118,861 km2 making it the second most important river in Poland as well as one of the most significant one in Central Europe. This paper examines the SMOS soil moisture data in the Odra river watershed in the period from 2010 to 2012. This attempt was made to check the possibility of assessing, from the low spatial resolution observations of SMOS, useful information that could be exploited for practical aims in watershed scale, for example, in water storage models even while moderate RFI takes place. Such studies, performed over the area of a large watershed, were recommended by researchers in order to obtain statistically significant results. To meet these expectations, Centre Aval de Traitement des Donnes SMOS (CATDS), 3-days averaged data, together with Global Land Data Assimilation System (GLDAS) National Centers for Environmental Prediction/Oregon State University/Air Force/Hydrologic Research Lab (NOAH) model 0.25 soil moisture values were used for statistical analyses and mutual comparisons. The results obtained using various statistical tools unveil high scientific potential of CATDS SMOS data to study soil moisture over the Odra river watershed. This was also confirmed by reasonable agreement between results derived from CATDS SMOS Ascending and GLDAS data sets. This agreement was achieved mainly by using these data spatially averaged over the whole watershed area, and for observations performed in the period longer than three-day averaging time. Comparisons of separate three-day data in a given pixel position, or at smaller areas would be difficult because of data gaps. Hence, the results of the work suggest that despite of RFI interferences, SMOS observations can provide effective input for analysis of soil moisture at regional scales. Moreover, it was shown that CATDS SMOS soil moisture data are better correlated with rainfall rate than GLDAS ones.
Watershed Boundary Dataset for Mississippi
Wilson, K. Van; Clair, Michael G.; Turnipseed, D. Phil; Rebich, Richard A.
2009-01-01
The U.S. Geological Survey, in cooperation with the Mississippi Department of Environmental Quality, U.S. Department of Agriculture-Natural Resources Conservation Service, Mississippi Department of Transportation, U.S. Department of Agriculture-Forest Service, and the Mississippi Automated Resource Information System developed a 1:24,000-scale Watershed Boundary Dataset for Mississippi including watershed and subwatershed boundaries, codes, names, and areas. The Watershed Boundary Dataset for Mississippi provides a standard geographical framework for water-resources and selected land-resources planning. The original 8-digit subbasins (Hydrologic Unit Codes) were further subdivided into 10-digit watersheds (62.5 to 391 square miles (mi2)) and 12-digit subwatersheds (15.6 to 62.5 mi2) - the exceptions being the Delta part of Mississippi and the Mississippi River inside levees, which were subdivided into 10-digit watersheds only. Also, large water bodies in the Mississippi Sound along the coast were not delineated as small as a typical 12-digit subwatershed. All of the data - including watershed and subwatershed boundaries, subdivision codes and names, and drainage-area data - are stored in a Geographic Information System database, which are available at: http://ms.water.usgs.gov/. This map shows information on drainage and hydrography in the form of U.S. Geological Survey hydrologic unit boundaries for water-resource 2-digit regions, 4-digit subregions, 6-digit basins (formerly called accounting units), 8-digit subbasins (formerly called cataloging units), 10-digit watershed, and 12-digit subwatersheds in Mississippi. A description of the project study area, methods used in the development of watershed and subwatershed boundaries for Mississippi, and results are presented in Wilson and others (2008). The data presented in this map and by Wilson and others (2008) supersede the data presented for Mississippi by Seaber and others (1987) and U.S. Geological Survey (1977).
Hydrogeological Studies of Mendhwan Watershed, Ahmadnagar District, Maharashtra, India
NASA Astrophysics Data System (ADS)
Muley, R. B.; Babar, Md.; Kulkarni, P. S.
2011-07-01
The Mendhwan watershed area is a part of chronic drought prone region of Ahmadnagar district of Maharashtra state, India which is considered for the study with reference to hydrogeological characteristics in Deccan basaltic terrain. In order to enhance groundwater availability and to demarcate the area of high groundwater potential, Geoforum, Parbhani Chapter has carried out hydrological investigation of this watershed area. Geologically, the study area belongs to the Deccan trap basalts of late Cretaceous to early Eocene period. The entire study area consists of thin irregular vesicular-amygdaloidal basalt flows also known as compound pahoehoe flows. The area is traversed by two prominent dykes, which are almost perpendicular to each other. In most of the southern part of the area, amygdaloidal basalt is exposed at the surface. The fresh amygdaloidal basalt flow is free from joints and occurs as homogeneous watertight mass. As dykes are jointed, they provide favorable conditions for percolation and ground water potential of this area is found to be satisfactory. It was observed that in Mendhwan area a large number of water conservation structures have been constructed across the streams. Incidentally groundwater potential shows notable increase only in those localities where the structures had been constructed on the dyke rock. The result of the study is found to be very much beneficial to the rural populace of this draught prone area so as to plan the optimum utilization of this precious natural resource.
Brady, Laura M.; Gray, Floyd; Wissler, Craig A.; Guertin, D. Phillip
2001-01-01
In this study, a geographic information system (GIS) is used to integrate and accurately map field studies, information from remotely sensed data, watershed models, and the dispersion of potentially toxic mine waste and tailings. The purpose of this study is to identify erosion rates and net sediment delivery of soil and mine waste/tailings to the drainage channel within several watershed regions to determine source areas of sediment delivery as a method of quantifying geo-environmental analysis of transport mechanisms in abandoned mine lands in arid climate conditions. Users of this study are the researchers interested in exploration of approaches to depicting historical activity in an area which has no baseline data records for environmental analysis of heavily mined terrain.
B. Poff; D. G. Neary; V. Henderson; A. Tecle
2012-01-01
Beginning in the 1950s, researchers of the United States Department of Agriculture Forest Service established a series of paired watershed studies throughout north-central and eastern Arizona. A total of nine experimental watershed areas were established in the pinyon-juniper and chaparral woodlands, as well as the ponderosa pine and mixed conifer forests. While most...
NASA Astrophysics Data System (ADS)
Rasskasova, N. S.; Bobylev, A. V.; Malaev, A. V.
2017-11-01
The authors have performed an analysis for the use of watershed areas of the lakes of the Eastern Zauralye district (the territory to the east of Ural) for national economic purposes. The analysis gave a possibility to assess the impact of watersheds depending on the applied technologies on the dump of various runoff into the reservoir waters. The watershed areas of all lakes have been found to be actively used as pastures, farmland and recreational resources. Some of the main sources of solid and liquid industrial waste are cattle farms and agricultural land using outdated equipment and technologies. The study of 26 km of the watershed line areas showed that pollutants (household garbage, fuels and lubricants) and organic substances (phosphorus and nitrogen) got into the waters of the reservoirs. The maximum runoff of solid and liquid waste into the waters of the lakes happens in summer which leads to increased concentrations of organic substances, an increase in productivity of alga and higher aquatic flora determining the degree of eutrophication and trophy in the reservoirs. The average annual trophic status of TSI lakes of the Eastern Zauralye district is 56 which corresponds to the typical phase of eutrophy. The reduced transparency of lakes is also the evidence of an increase in biological productivity of reservoirs, their eutrophication and, as a result, the water quality deterioration. The intensive eutrophication of reservoirs, in its turn, most significantly affects the concentration of the ammonium form of nitrogen, total phosphorus and total nitrogen, increase in pH and deterioration of oxygen condition. The authors have developed various activities to reduce a technogenic risk in the watershed areas of the lakes in the Eastern Zauralye district which can be applied to other areas using the analogy method.
Automated watershed subdivision for simulations using multi-objective optimization
USDA-ARS?s Scientific Manuscript database
The development of watershed management plans to evaluate placement of conservation practices typically involves application of watershed models. Incorporating spatially variable watershed characteristics into a model often requires subdividing the watershed into small areas to accurately account f...
Effects of chronic ammonium sulfate treatment on the forest at the Bear Brook Watershed in Maine.
Elvir, Jose Alexander; Wiersma, G Bruce; Bethers, Suzanne; Kenlan, Peter
2010-12-01
At the Bear Brook Watershed in Maine (BBWM), the forest tree composition was characterized and the effects of the chronic ammonium sulfate ((NH(4))(2)SO(4)) treatment on basal area growth, foliar chemistry, and gas exchange were investigated on forest species. The BBWM is a paired watershed forest ecosystem study with one watershed, West Bear (WB), treated since 1989 with 26.6 kg N ha(-1) year(-1) and 30 kg S ha(-1) year(-1)applied bimonthly as (NH(4))(2)SO(4), while the other watershed, East Bear (EB), serves as a reference. Tree species richness, density, and mortality were found to be similar between watersheds. Basal area increment was estimated from red spruce and sugar maple, showing that, for the first 7 years of treatment, it was significantly higher for sugar maple growing in WB compared to EB, but no differences were observed for red spruce between watersheds. However, the initial higher sugar maple basal area growth in WB subsequently decreased after 8 years of treatment. Foliar chemical analysis performed in trees, saplings, and ground flora showed higher N concentrations in the treated WB compared to the reference EB. But, foliar cation concentrations, especially Ca and Mg, were significantly lower for most of the species growing in WB compared with those growing in EB. For sugar maple, foliar N was higher on WB, but there were no differences in foliar Ca and Mg concentrations between treated and reference watersheds. In addition, only sugar maple trees in the treated WB showed significantly higher photosynthetic rates compared to reference EB trees.
Hydrologic land use classification of the Patuxent River watershed using remotely sensed data
NASA Technical Reports Server (NTRS)
Dallam, W. C.; Rango, A.; Shima, L.
1975-01-01
The Patuxent River Watershed is located in central Maryland between Baltimore and Washington, D.C. and is approximately 2330 sq km in area and 175 km long. This region is now at a critical point because of major concerns such as water management and quality, flooding and land use within the watershed. Data from the NASA-directed LANDSAT and Earth Resources Aircraft Programs were used to provide a new dimension in information collection and processing for the management of watersheds. Digital data from LANDSAT-1 were analyzed along with selected IR photography from U-2 flight number 74-060B taken 28 April 1974, which was digitized in three channels. Processing of the data was accomplished using a multispectral analysis system. Land use themes consisting of surface water, wetlands, forest, residential, cropland/pasture, urban, and extractive were developed and delineated through the watershed. Area measurements of watershed themes were obtained and will serve as a calibration input to a deterministic hydrologic model on a sub-watershed. Using the derived residential and urban theme areas from LANDSAT an estimated basin imperviousness was also calculated. Thematic maps were produced at 1:62,500 scale. Floodprone areas were also classified and delineated at a scale of 1:24,000. Comparison with standard floodprone area maps at the same scale have indicated a few areas of discrepancy. Such information can be used for updating or checking floodprone area boundaries as well as monitoring changes in floodplain areas.
Doyle, W. Harry
1981-01-01
A requirement of Public Law 95-87, the Surface Mining Control and Reclamation Act of 1977, is the understanding of the hydrology in actual and proposed surface-mined areas. Surface-water data for small specific-sites and for larger areas such as adjacent and general areas are needed also to satisfy the hydrologic requirements of the Act. The Act specifies that surface-water modeling techniques may be used to generate the data and information. The purpose of this report is to describe how this can be achieved for smaller watersheds. This report also characterizes 12 ' state-of-the-art ' strip-mining assessment models that are to be tested with data from two data-intensive studies involving small watersheds in Tennessee and Indiana. Watershed models are best applied to small watersheds with specific-site data. Extending the use of modeling techniques to larger watersheds remains relatively untested, and to date the upper limits for application have not been established. The U.S. Geological Survey is currently collecting regional hydrologic data in the major coal provinces of the United States and this data will be used to help satisfy the ' general-area ' data requirements of the Act. This program is reviewed and described in this report. (USGS)
NASA Astrophysics Data System (ADS)
Rong, Q. Q.; Su, M. R.; Yang, Z. F.; Cai, Y. P.; Yue, W. C.; Dang, Z.
2018-02-01
In this research, the Dongjiang River basin was taken as the study area to analyze the spatial distribution and output characteristics of nonpoint source pollution, based on the export coefficient model. The results showed that the annual total nitrogen and phosphorus (i.e. TN and TP) loads from the Dongjiang River basin were 67916114.6 and 7215279.707 kg, respectively. Residents, forestland and pig were the main contributors for the TN load in the Dongjiang River basin, while residents, forestland and rainfed croplands were the three largest contributors for the TP load. The NPS pollution had a significant spatial variation in this area. The pollution loads overall decreased from the northeast to the southwest part of the basin. Also, the pollution loads from the gentle slope area were larger than those from steep slope areas. Among the ten tributary watersheds in the Dongjiang River basin, the TN and TP loads from the Hanxi River watershed were the largest. On the contrary, the Gongzhuang River watershed contributed least to the total pollution loads of the Dongjiang River basin. For the average pollution load intensities, Hanxi River watershed was still the largest. However, the smallest average TN and TP load intensities were in the Xinfeng River watershed.
Nutrients in Streams and Rivers Across the Nation -- 1992-2001
Mueller, David K.; Spahr, Norman E.
2006-01-01
Nutrient compounds of nitrogen and phosphorus were investigated in streams and rivers sampled as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program. Nutrient data were collected in 20 NAWQA study units during 1992-95, 16 study units during 1996-98, and 15 study units during 1999-2001. To facilitate comparisons among sampling sites with variable sampling frequency, daily loads were determined by using regression models that relate constituent transport to streamflow and time. Model results were used to compute mean annual loads, yields, and concentrations of ammonia, nitrate, total nitrogen, orthophosphate, and total phosphorus, which were compared among stream and river sampling sites. Variations in the occurrence and distribution of nutrients in streams and rivers on a broad national scale reflect differences in the sources of nutrient inputs to the upstream watersheds and in watershed characteristics that affect movement of those nutrients. Sites were classified by watershed size and by land use in the upstream watershed: agriculture, urban, and undeveloped (forest or rangeland). Selection of NAWQA urban sites was intended to avoid effects of major wastewater-treatment plants and other point sources, but in some locations this was not feasible. Nutrient concentrations and yields generally increased with anthropogenic development in the watershed. Median concentrations and yields for all constituents at sites downstream from undeveloped areas were less than at sites downstream from agricultural or urban areas. Concentrations of ammonia, orthophosphate, and total phosphorus at agricultural and urban sites were not significantly different; however, concentrations of nitrate and total nitrogen were higher at agricultural than at urban sites. Total nitrogen concentrations at agricultural sites were higher in areas of high nitrogen input or enhanced transport, such as irrigation or artificial drainage that can rapidly move water from cropland to streams (Midwest, Northern Plains, and western areas of the United States). Concentrations were lower in the Southeast, where more denitrification occurs during transport of nitrogen compounds in shallow ground water. At urban sites, high concentrations of ammonia and orthophosphate were more prevalent downstream from wastewater-treatment plants. At sites with large watersheds and high mean-annual streamflow ('large-watershed' sites), concentrations of most nutrients were significantly less than at sites downstream from agricultural or urban areas. Total nitrogen concentrations at large-watershed sites were higher in Midwest agricultural areas and lower in the Western United States, where agricultural and urban development is less extensive. Total phosphorus concentrations at large-watershed sites were higher in areas of greater potential erosion and low overall runoff such as the arid areas in the West. Although not as distinct as seasonal patterns of streamflow, geographic patterns of seasonally high and low concentrations of total nitrogen and total phosphorus were identified in the data. Seasonal patterns in concentrations of total nitrogen generally mirror seasonal patterns in streamflow in the humid Eastern United States but are inverse to seasonal patterns in streamflow in the semiarid interior West. Total phosphorus concentrations typically have the opposite regional relation with streamflow; high concentrations coincide with high streamflows in the interior West. In the NAWQA Program, sites downstream from relatively undeveloped areas were selected to provide a baseline for comparison to sites with potential effects of urban development and agriculture. Concentrations of nitrate, total nitrogen, and total phosphorus at NAWQA undeveloped sites were found to be greater than values reported by other studies for conditions of essentially no development (background conditions). Concentrations at NAWQA undeveloped sites represent conditions
IDENTIFICATION OF SEDIMENT SOURCE AREAS WITHIN A WATERSHED
Two methods, one using a travel time approach and the other based on optimization techniques, were developed to identify sediment generating areas within a watershed. Both methods rely on hydrograph and sedimentograph data collected at the mouth of the watershed. Data from severa...
NASA Astrophysics Data System (ADS)
Vema, Vamsikrishna; Sudheer, K. P.; Chaubey, I.
2017-08-01
Watershed hydrological models are effective tools for simulating the hydrological processes in the watershed. Although there are a plethora of hydrological models, none of them can be directly applied to make water conservation decisions in irregularly bounded areas that do not confirm to topographically defined ridge lines. This study proposes a novel hydrological model that can be directly applied to any catchment, with or without ridge line boundaries. The model is based on the water balance concept, and a linear function concept to approximate the cross-boundary flow from upstream areas to the administrative catchment under consideration. The developed model is tested in 2 watersheds - Riesel Experimental Watershed and a sub-basin of Cedar Creek Watershed in Texas, USA. Hypothetical administrative catchments that did not confirm to the location of ridge lines were considered for verifying the efficacy of the model for hydrologic simulations. The linear function concept used to account the cross boundary flow was based on the hypothesis that the flow coming from outside the boundary to administrative area was proportional to the flow generated in the boundary grid cell. The model performance was satisfactory with an NSE and r2 of ≥0.80 and a PBIAS of <25 in all the cases. The simulated hydrographs for the administrative catchments of the watersheds were in good agreement with the observed hydrographs, indicating a satisfactory performance of the model in the administratively bounded areas.
Impacts of urban sprawl on the area of downtown lakes in a highly developing city on central China
NASA Astrophysics Data System (ADS)
Zhang, W.; Zhang, Y.
2016-12-01
Wuhan city in central China is full of water resources and numerous lakes are located. Downtown lakes have significant ecological value and ornamental value for urban inhabitants in Wuhan. Under the rapid process of urban sprawl, downtown lakes are occupied by impervious areas. This research uses Landsat images to extract land uses from 1991 to 2013 in Wuhan city , and attempts to find out how urban sprawl affects the water body area decline in space. Two largest downtown lakes in Wuhan city, Donghu Lake located in central city and Tangxunhu Lake located in suburbs, are taken as case study area. A direction change index (DCI) is proposed to evaluate the changes of a specific land use in different directions. The results reveal that two downtown lakes are undergoing rapid water body area decline from 1991 to 2013, with decline rate are -0.022 in Donghu watershed and -0.011 in Tangxunhu watershed. 68.26% and 62.50% of the reduced water body is occupied by built-up land in Donghu watershed and Tangxunhu watershed, respectively. According to DCI, the water body reduce is highly correlated with built-up land increase in all direction. Moreover, it is found that in the Donghu watershed the north-west part suffered significant water body area decline, which is close to central city. While in Tangxunhu watershed, the area of water body declined in north-west, south-west and north-east part, and the area obstructed from central city by the lake was suffering less water body area decline. It is concluded that the water body area of downtown lakes are highly affected by the process of urban sprawl, and the lakes in central districts trends to suffer higher descend than that of the downtown lake located in suburbs. Meanwhile, even for the same downtown lake, the area orientating and close to the central city may suffer more rapid decline than the area that does not orientate to the central city.
NASA Astrophysics Data System (ADS)
Liu, Y.; Engel, B.; Collingsworth, P.; Pijanowski, B. C.
2017-12-01
Nutrient loading from the Maumee River watershed is a significant reason for the harmful algal blooms (HABs) problem in Lake Erie. Strategies to reduce nutrient loading from agricultural areas in the Maumee River watershed need to be explored. Best management practices (BMPs) are popular approaches for improving hydrology and water quality. Various scenarios of BMP implementation were simulated in the AXL watershed (an agricultural watershed in Maumee River watershed) using Soil and Water Assessment Tool (SWAT) and a new BMP cost tool to explore the cost-effectiveness of the practices. BMPs of interest included vegetative filter strips, grassed waterways, blind inlets, grade stabilization structures, wetlands, no-till, nutrient management, residue management, and cover crops. The following environmental concerns were considered: streamflow, Total Phosphorous (TP), Dissolved Reactive Phosphorus (DRP), Total Kjeldahl Nitrogen (TKN), and Nitrate+Nitrite (NOx). To obtain maximum hydrological and water quality benefits with minimum cost, an optimization tool was developed to optimally select and place BMPs by connecting SWAT, the BMP cost tool, and optimization algorithms. The optimization tool was then applied in AXL watershed to explore optimization focusing on critical areas (top 25% of areas with highest runoff volume/pollutant loads per area) vs. all areas of the watershed, optimization using weather data for spring (March to July, due to the goal of reducing spring phosphorus in watershed management plan) vs. full year, and optimization results of implementing BMPs to achieve the watershed management plan goal (reducing 2008 TP levels by 40%). The optimization tool and BMP optimization results can be used by watershed groups and communities to solve hydrology and water quality problems.
NASA Astrophysics Data System (ADS)
Steenhuis, T. S.; Mendoza, G.; Lyon, S. W.; Gerard Marchant, P.; Walter, M. T.; Schneiderman, E.
2003-04-01
Because the traditional Soil Conservation Service Curve Number (SCS-CN) approach continues to be ubiquitously used in GIS-BASED water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed within an integrated GIS modeling environment a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Spatial representation of hydrologic processes is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point source pollution. The methodology presented here uses the traditional SCS-CN method to predict runoff volume and spatial extent of saturated areas and uses a topographic index to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was incorporated in an existing GWLF water quality model and applied to sub-watersheds of the Delaware basin in the Catskill Mountains region of New York State. We found that the distributed CN-VSA approach provided a physically-based method that gives realistic results for watersheds with VSA hydrology.
Hydrology and water quality in 13 watersheds in Gwinnett County, Georgia, 2001–15
Aulenbach, Brent T.; Joiner, John K.; Painter, Jaime A.
2017-02-23
The U.S. Geological Survey (USGS), in cooperation with Gwinnett County Department of Water Resources, established a Long-Term Trend Monitoring (LTTM) program in 1996. The LTTM program is a comprehensive, long-term, water-quantity and water-quality monitoring program designed to document and analyze the hydrologic and water-quality conditions of selected watersheds in Gwinnett County, Georgia. Water-quality monitoring initially began in six watersheds and currently [2016] includes 13 watersheds.As part of the LTTM program, streamflow, precipitation, water temperature, specific conductance, and turbidity were measured every 15 minutes for water years 2001–15 at 12 of the 13 watershed monitoring stations and for water years 2010–15 at the other watershed. In addition, discrete water-quality samples were collected seasonally from May through October (summer) and November through April (winter), including one base-flow and three stormflow event composite samples, during the study period. Samples were analyzed for nutrients (nitrogen and phosphorus), total organic carbon, trace elements (total lead and total zinc), total dissolved solids, and total suspended sediment (total suspended solids and suspended-sediment concentrations). The sampling scheme was designed to identify variations in water quality both hydrologically and seasonally.The 13 watersheds were characterized for basin slope, population density, land use for 2012, and the percentage of impervious area from 2000 to 2014. Several droughts occurred during the study period—water years 2002, 2007–08, and 2011–12. Watersheds with the highest percentage of impervious areas had the highest runoff ratios, which is the portion of precipitation that occurs as runoff. Watershed base-flow indexes, the ratio of base-flow runoff to total runoff, were inversely correlated with watershed impervious area.Flood-frequency estimates were computed for 13 streamgages in the study area that have 10 or more years of annual peak flow data through water year 2015, using the expected moments algorithm to fit a Pearson Type III distribution to logarithms of annual peak flows. Kendall’s tau nonparametric test was used to determine the statistical significance of trends in the annual peak flows, with none of the 13 streamgages exhibiting significant trends.A comparison of base-flow and stormflow water-quality samples indicates that turbidity and concentrations of total ammonia plus organic nitrogen, total nitrogen, total phosphorus, total organic carbon, total lead, total zinc, total suspended solids, and suspended-sediment concentrations increased with increasing discharge at all watersheds. Specific conductance decreased during stormflow at all watersheds, and total dissolved solids concentrations decreased during stormflow at a few of the watersheds. Total suspended solids and suspended-sediment concentrations typically were two orders of magnitude higher in stormflow samples, turbidities were about 1.5 orders of magnitude higher, total phosphorus and total zinc were about one order of magnitude higher, and total ammonia plus organic nitrogen, total nitrogen, total organic carbon, and total lead were about twofold higher than in base-flow samples.Seasonality and long-term trends were identified for the period water years 2001–15 for 10 constituents—total nitrogen, total nitrate plus nitrite, total phosphorus, dissolved phosphorus, total organic carbon, total suspended solids, suspended-sediment concentration, total lead, total zinc, and total dissolved solids. Seasonal patterns were present in most watersheds for all constituents except total dissolved solids, and the watersheds had fairly similar patterns of higher concentrations in the summer and lower concentrations in the winter. A linear long-term trend analysis of residual concentrations from the flow-only load estimation model (without time-trend terms) identified significant trends in 67 of the 130 constituent-watershed combinations. Seventy percent of the significant trends were negative. Total organic carbon and total dissolved solids had predominantly positive trends. Total phosphorus, total suspended solids, suspended-sediment concentration, total lead, and total zinc had only negative trends. The other three constituents exhibited fewer trends, both positive and negative.Streamwater loads were estimated annually for the 13-year period water years 2003–15 for the same 10 constituents in the trend analysis. Loads were estimated using a regression-model-based approach developed by the USGS for the Gwinnett County LTTM program that accommodates the use of storm-event composited samples. Concentrations were modeled as a function of discharge, base flow, time, season, and turbidity to improve model predictions and reduce errors in load estimates. Total suspended solids annual loads have been identified in Gwinnett County’s Watershed Protection Plan for target performance criterion.Although the amount of annual runoff was the primary factor in variations in annual loads, climatic conditions (classified as dry, average, or wet) affected annual loads beyond what was attributed to climatic-related variations in annual runoff. Significant negative trends in loads were estimated for the combined area of the watersheds for all constituents except dissolved phosphorus, total organic carbon, and total dissolved solids. The trend analysis indicated that total suspended solids and suspended-sediment concentration loads in the study area were decreasing by 57,000 and 87,000 pounds per day per year, respectively.Variations in constituent yields between watersheds appeared to be related to various watershed characteristics. Suspended sediment (as either total suspended solids or suspended-sediment concentrations), along with constituents transported predominately in solid phase (total phosphorus, total organic carbon, total lead, and total zinc), and total dissolved solids typically had higher yields from watersheds that had high percentages of impervious areas or high basin slope. High total nitrogen yields were also associated with watersheds with high percentages of impervious areas. Low total nitrogen, total suspended solids, total lead, and total zinc yields appeared to be associated with watersheds that had a low percentage of high-density development.
Protect and Restore Lolo Creek Watershed, 2002-2003 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2004-01-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Lolo Creek watershed are coordinated with the Clearwater National Forest and Potlatch Corporation. The Nez Perce Tribe began watershed restoration projects within the Lolo Creek watershed of the Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing, stabilizing streambanks, decommissioning roads, and upgrading culverts. During the years 2000-2003, trees were planted in riparian areas of headwater streams to Lolo Creek. Inventory of culvertsmore » is an on-going practice, being completed by sub-drainage, and are being prioritized for replacement to accommodate fish passage and 100-year flow events throughout the watershed. Tribal crews completed maintenance to the previously built fence.« less
Rose, W.J.; Graczyk, D.J.
1996-01-01
There was little relation between watershed area and sediment loads for the three sites. The watershed of site C is about 41 percent of that of site A, but the sand load at site C was only 1 percent of that at site A. The watershed area between sites B and C is 40 percent of that above site A, but this area yielded 49 percent of the sand load at site A. Nineteen percent of the watershed above site A is between sites A and B, yet this area yielded about 50 percent of the sand load at site A.
Spectral Measurement of Watershed Coefficients in the Southern Great Plains
NASA Technical Reports Server (NTRS)
Blanchard, B. J. (Principal Investigator); Bausch, W.
1978-01-01
The author has identified the following significant results. It was apparent that the spectra calibration of runoff curve numbers cannot be achieved on watersheds where significant areas of timber were within the drainage area. The absorption of light by wet soil conditions restricts differentiation of watersheds with regard to watershed runoff curve numbers. It appeared that the predominant factor influencing the classification of watershed runoff curve numbers was the difference in soil color and its associated reflectance when dry. In regions where vegetation grown throughout the year, where wet surface conditions prevail or where watersheds are timbered, there is little hope of classifying runoff potential with visible light alone.
NASA Astrophysics Data System (ADS)
Rogelis, Carolina; Werner, Micha
2013-04-01
Settlements in peri-urban areas of many cities in mountainous areas such as in the Andes are susceptible to hazards such as flash floods and debris flows. Additionally these settlements are in many cases informal and thus vulnerable to such hazards, resulting in significant risk. Such watersheds are often quiet small, and generally there is little or no information from gauges to help characterise risk. To help identify watersheds in which flood management measures are to be targeted, a rapid assessment of risk is required. In this paper a novel approach is presented where indicators of susceptibility and vulnerability to flash floods were used to prioritize 106 mountain watersheds in Bogotá (Colombia). Variables recognized in literature to determine the dominant processes both in susceptibility and vulnerability to flash floods were used to construct the indicators. Susceptibility was considered to increase with flashiness and the possibility of debris flow events occurring. This was assessed through the use of an indicator composed of a morphometric indicator and a land use indicator. The former was constructed using morphological variables recognized in literature to significantly influence flashiness and occurrence of debris flows; the latter was constructed in terms of percentage of vegetation cover, urban area and bare soil. The morphometric indicator was compared with the results of a debris flow propagation algorithm to assess its capacity in indentifying the morphological conditions of a watershed that make it able to transport debris flows. Propagation was carried out through the use of the Modified Single Flow Direction algorithm, following previous identification of source areas by applying thresholds identified in the area-slope curve of the watersheds and empirical thresholds. Results show that the morphometric variables can be grouped in four categories: size, shape, hypsometry and energy, with the energy the component found to best explain the capability of the watershed to transport debris flows. The combination of the morphometric and land use indicators resulted in a susceptibility indicator that was compared with the available records of past floods in the area. This showed that the use of the land use indicator significantly improves the susceptibility assessment. Vulnerability was assessed in terms of indicators representing physical exposure, fragility of the socio-economic system and lack of resilience to cope and recover. Principal component analysis was subsequently applied to reduce variables and provide a representation of each of their facets by a component. This resulted in a composite indicator of susceptibility and vulnerability for each of the 106 watersheds. The indicator was compared with the history of flash flood damage in the watersheds. Results show that the indicator is useful in applications at regional scales for preliminary assessment to differentiate at spatial level the degree of flood susceptibility and vulnerability. This provides an initial and qualitative risk outlook in the study area and can be used for planning and prioritization of further more detailed studies.
Hydrologic analysis for selection and placement of conservation practices at the watershed scale
NASA Astrophysics Data System (ADS)
Wilson, C.; Brooks, E. S.; Boll, J.
2012-12-01
When a water body is exceeding water quality standards and a Total Maximum Daily Load has been established, conservation practices in the watershed are able to reduce point and non-point source pollution. Hydrological analysis is needed to place conservation practices in the most hydrologically sensitive areas. The selection and placement of conservation practices, however, is challenging in ungauged watersheds with little or no data for the hydrological analysis. The objective of this research is to perform a hydrological analysis for mitigation of erosion and total phosphorus in a mixed land use watershed, and to select and place the conservation practices in the most sensitive areas. The study area is the Hangman Creek watershed in Idaho and Washington State, upstream of Long Lake (WA) reservoir, east of Spokane, WA. While the pollutant of concern is total phosphorus (TP), reductions in TP were translated to total suspended solids or reductions in nonpoint source erosion and sediment delivery to streams. Hydrological characterization was done with a simple web-based tool, which runs the Water Erosion Prediction Project (WEPP) model for representative land types in the watersheds, where a land type is defined as a unique combination of soil type, slope configuration, land use and management, and climate. The web-based tool used site-specific spatial and temporal data on land use, soil physical parameters, slope, and climate derived from readily available data sources and provided information on potential pollutant pathways (i.e. erosion, runoff, lateral flow, and percolation). Multiple land types representative in the watershed were ordered from most effective to least effective, and displayed spatially using GIS. The methodology for the Hangman Creek watershed was validated in the nearby Paradise Creek watershed that has long-term stream discharge and monitoring as well as land use data. Output from the web-based tool shows the potential reductions for different tillage practices, buffer strips, streamside management, and conversion to the conservation reserve program in the watershed. The output also includes the relationship between land area where conservation practices are placed and the potential reduction in pollution, showing the diminished returns on investment as less sensitive areas are being treated. This application of a simple web-based tool and the use of a physically-based erosion model (i.e. WEPP) illustrates that quantitative, spatial and temporal analysis of changes in pollutant loading and site-specific recommendations of conservation practices can be made in ungauged watersheds.
Lee, Casey J.; Rasmussen, Patrick P.; Ziegler, Andrew C.; Fuller, Christopher C.
2009-01-01
The U.S. Geological Survey, in cooperation with the Johnson County Stormwater Management Program, evaluated suspended-sediment transport and sources in the urbanizing, 57.4 mi2 Mill Creek watershed from February 2006 through June 2007. Sediment transport and sources were assessed spatially by continuous monitoring of streamflow and turbidity as well as sampling of suspended sediment at nine sites in the watershed. Within Mill Creek subwatersheds (2.8-16.9 mi2), sediment loads at sites downstream from increased construction activity were substantially larger (per unit area) than those at sites downstream from mature urban areas or less-developed watersheds. Sediment transport downstream from construction sites primarily was limited by transport capacity (streamflow), whereas availability of sediment supplies primarily influenced transport downstream from mature urban areas. Downstream sampling sites typically had smaller sediment loads (per unit area) than headwater sites, likely because of sediment deposition in larger, less sloping stream channels. Among similarly sized storms, those with increased precipitation intensity transported more sediment at eight of the nine monitoring sites. Storms following periods of increased sediment loading transported less sediment at two of the nine monitoring sites. In addition to monitoring performed in the Mill Creek watershed, sediment loads were computed for the four other largest watersheds (48.6-65.7 mi2) in Johnson County (Blue River, Cedar, Indian, and Kill Creeks) during the study period. In contrast with results from smaller watersheds in Mill Creek, sediment load (per unit area) from the most urbanized watershed in Johnson County (Indian Creek) was more than double that of other large watersheds. Potential sources of this sediment include legacy sediment from earlier urban construction, accelerated stream-channel erosion, or erosion from specific construction sites, such as stream-channel disturbance during bridge renovation. The implication of this finding is that sediment yields from larger watersheds may remain elevated after the majority of urban development is complete. Surface soil, channel-bank, suspended-sediment, and streambed-sediment samples were analyzed for grain size, nutrients, trace elements, and radionuclides in the Mill Creek watershed to characterize suspended sediment between surface or channel-bank sources. Although concentrations and activities of cobalt, nitrogen, selenium, total organic carbon, cesium-137, and excess lead-210 had significant differences between surface and channel-bank samples, biases resulting from urban construction, additional sorption of constituents during sediment transport, and inability to accurately represent erosion from rills and gullies precluded accurate characterization of suspended-sediment source.
Remote sensing of effects of land use practices on water quality
NASA Technical Reports Server (NTRS)
Graves, D. H.; Colthrap, G. B.
1977-01-01
An intensive study was conducted to determine the utility of manual densitometry and color additive viewing of aircraft and LANDSAT transparencies for monitoring land use and land use change. The relationship between land use and selected water quality parameters was also evaluated. Six watersheds located in the Cumberland Plateau region of eastern Kentucky comprised the study area for the project. Land uses present within the study area were reclaimed surface mining and forestry. Fertilization of one of the forested watersheds also occurred during the study period.
Space-Air Co-Observation in Watershed Management: the Establishment of System
NASA Astrophysics Data System (ADS)
Zhong, L.; Yu, J.; Tang, X.; Pan, S.
2018-05-01
To realize real-time, detailed, and standardized watershed monitoring and management, a dynamic monitoring system is proposed, at all levels (space, air, and ground), by comprehensively utilizing advanced satellite and low-altitude unmanned aerial vehicle (UAV) technologies The system can be used to monitor and manage all kinds of sensitive water targets. This study takes water administration enforcement as an example for proving it feasibility by selecting typical study areas. This study shows that the proposed system is a promising information acquisition means, contributing to the development of watershed management.
Approach and case-study of green infrastructure screening analysis for urban stormwater control.
Eaton, Timothy T
2018-03-01
Urban stormwater control is an urgent concern in megacities where increased impervious surface has disrupted natural hydrology. Water managers are increasingly turning to more environmentally friendly ways of capturing stormwater, called Green Infrastructure (GI), to mitigate combined sewer overflow (CSO) that degrades local water quality. A rapid screening approach is described to evaluate how GI strategies can reduce the amount of stormwater runoff in a low-density residential watershed in New York City. Among multiple possible tools, the L-THIA LID online software package, using the SCS-CN method, was selected to estimate relative runoff reductions expected with different strategies in areas of different land uses in the watershed. Results are sensitive to the relative areas of different land uses, and show that bioretention and raingardens provide the maximum reduction (∼12%) in this largely residential watershed. Although commercial, industrial and high-density residential areas in the watershed are minor, larger runoff reductions from disconnection strategies and porous pavement in parking lots are also possible. Total stormwater reductions from various combinations of these strategies can reach 35-55% for individual land uses, and between 23% and 42% for the entire watershed. Copyright © 2017. Published by Elsevier Ltd.
NASA Astrophysics Data System (ADS)
Guo, B.
2017-12-01
Mountain watershed in Western China is prone to flash floods. The Wenchuan earthquake on May 12, 2008 led to the destruction of surface, and frequent landslides and debris flow, which further exacerbated the flash flood hazards. Two giant torrent and debris flows occurred due to heavy rainfall after the earthquake, one was on August 13 2010, and the other on August 18 2010. Flash floods reduction and risk assessment are the key issues in post-disaster reconstruction. Hydrological prediction models are important and cost-efficient mitigation tools being widely applied. In this paper, hydrological observations and simulation using remote sensing data and the WMS model are carried out in the typical flood-hit area, Longxihe watershed, Dujiangyan City, Sichuan Province, China. The hydrological response of rainfall runoff is discussed. The results show that: the WMS HEC-1 model can well simulate the runoff process of small watershed in mountainous area. This methodology can be used in other earthquake-affected areas for risk assessment and to predict the magnitude of flash floods. Key Words: Rainfall-runoff modeling. Remote Sensing. Earthquake. WMS.
Qiu, Jiali; Shen, Zhenyao; Wei, Guoyuan; Wang, Guobo; Xie, Hui; Lv, Guanping
2018-03-01
The assessment of peak flow rate, total runoff volume, and pollutant loads during rainfall process are very important for the watershed management and the ecological restoration of aquatic environment. Real-time measurements of rainfall-runoff and pollutant loads are always the most reliable approach but are difficult to carry out at all desired location in the watersheds considering the large consumption of material and financial resources. An integrated environmental modeling approach for the estimation of flash streamflow that combines the various hydrological and quality processes during rainstorms within the agricultural watersheds is essential to develop targeted management strategies for the endangered drinking water. This study applied the Hydrological Simulation Program-Fortran (HSPF) to simulate the spatial and temporal variation in hydrological processes and pollutant transport processes during rainstorm events in the Miyun Reservoir watershed, a drinking water resource area in Beijing. The model performance indicators ensured the acceptable applicability of the HSPF model to simulate flow and pollutant loads in the studied watershed and to establish a relationship between land use and the parameter values. The proportion of soil and land use was then identified as the influencing factors of the pollution intensities. The results indicated that the flush concentrations were much higher than those observed during normal flow periods and considerably exceeded the limits of Class III Environmental Quality Standards for Surface Water (GB3838-2002) for the secondary protection zones of the drinking water resource in China. Agricultural land and leached cinnamon soils were identified as the key sources of sediment, nutrients, and fecal coliforms. Precipitation volume was identified as a driving factor that determined the amount of runoff and pollutant loads during rainfall processes. These results are useful to improve the streamflow predictions, provide useful information for the identification of highly polluted areas, and aid the development of integrated watershed management system in the drinking water resource area.
Restore McComas Meadows; Meadow Creek Watershed, 2003-2004 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2006-08-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated and cost shared with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing, planting trees in riparian areas within the meadow and its tributaries, prioritizing culverts for replacement to accommodate fish passage, and decommissioning roads tomore » reduce sediment input. Designs for culvert replacements are being coordinated with the Nez Perce National Forest. 20 miles of roads were decommissioned. Tribal crews completed maintenance to the previously built fence.« less
Temporal variation in spatial sources of discharge in a large watershed
We examined how the spatial configuration of source areas for runoff varied over time in a watershed contaminated with mercury in order to understand processes governing material loading to rivers. Source areas within the Fox River watershed (Wisconsin, USA) were mapped for indiv...
NASA Astrophysics Data System (ADS)
Dong, Feifei; Liu, Yong; Wu, Zhen; Chen, Yihui; Guo, Huaicheng
2018-07-01
Targeting nonpoint source (NPS) pollution hot spots is of vital importance for placement of best management practices (BMPs). Although physically-based watershed models have been widely used to estimate nutrient emissions, connections between nutrient abatement and compliance of water quality standards have been rarely considered in NPS hotspot ranking, which may lead to ineffective decision-making. It's critical to develop a strategy to identify priority management areas (PMAs) based on water quality response to nutrient load mitigation. A water quality constrained PMA identification framework was thereby proposed in this study, based on the simulation-optimization approach with ideal load reduction (ILR-SO). It integrates the physically-based Soil and Water Assessment Tool (SWAT) model and an optimization model under constraints of site-specific water quality standards. To our knowledge, it was the first effort to identify PMAs with simulation-based optimization. The SWAT model was established to simulate temporal and spatial nutrient loading and evaluate effectiveness of pollution mitigation. A metamodel was trained to establish a quantitative relationship between sources and water quality. Ranking of priority areas is based on required nutrient load reduction in each sub-watershed targeting to satisfy water quality standards in waterbodies, which was calculated with genetic algorithm (GA). The proposed approach was used for identification of PMAs on the basis of diffuse total phosphorus (TP) in Lake Dianchi Watershed, one of the three most eutrophic large lakes in China. The modeling results demonstrated that 85% of diffuse TP came from 30% of the watershed area. Compared with the two conventional targeting strategies based on overland nutrient loss and instream nutrient loading, the ILR-SO model identified distinct PMAs and narrowed down the coverage of management areas. This study addressed the urgent need to incorporate water quality response into PMA identification and showed that the ILR-SO approach is effective to guide watershed management for aquatic ecosystem restoration.
NASA Astrophysics Data System (ADS)
Samaras, Achilleas G.; Koutitas, Christopher G.
2014-04-01
Coastal morphology evolves as the combined result of both natural- and human- induced factors that cover a wide range of spatial and temporal scales of effect. Areas in the vicinity of natural stream mouths are of special interest, as the direct connection with the upstream watershed extends the search for drivers of morphological evolution from the coastal area to the inland as well. Although the impact of changes in watersheds on the coastal sediment budget is well established, references that study concurrently the two fields and the quantification of their connection are scarce. In the present work, the impact of land-use changes in a watershed on coastal erosion is studied for a selected site in North Greece. Applications are based on an integrated approach to quantify the impact of watershed management on coastal morphology through numerical modeling. The watershed model SWAT and a shoreline evolution model developed by the authors (PELNCON-M) are used, evaluating with the latter the performance of the three longshore sediment transport rate formulae included in the model formulation. Results document the impact of crop abandonment on coastal erosion (agricultural land decrease from 23.3% to 5.1% is accompanied by the retreat of ~ 35 m in the vicinity of the stream mouth) and show the effect of sediment transport formula selection on the evolution of coastal morphology. Analysis denotes the relative importance of the parameters involved in the dynamics of watershed-coast systems, and - through the detailed description of a case study - is deemed to provide useful insights for researchers and policy-makers involved in their study.
Watershed-based Morphometric Analysis: A Review
NASA Astrophysics Data System (ADS)
Sukristiyanti, S.; Maria, R.; Lestiana, H.
2018-02-01
Drainage basin/watershed analysis based on morphometric parameters is very important for watershed planning. Morphometric analysis of watershed is the best method to identify the relationship of various aspects in the area. Despite many technical papers were dealt with in this area of study, there is no particular standard classification and implication of each parameter. It is very confusing to evaluate a value of every morphometric parameter. This paper deals with the meaning of values of the various morphometric parameters, with adequate contextual information. A critical review is presented on each classification, the range of values, and their implications. Besides classification and its impact, the authors also concern about the quality of input data, either in data preparation or scale/the detail level of mapping. This review paper hopefully can give a comprehensive explanation to assist the upcoming research dealing with morphometric analysis.
Kumar, Amit; Chawla, Amit; Rajkumar, S
2011-08-01
The development activities in mountainous region though provide comfort to the human being and enhance the socioeconomic status of the people but create pressure on the bio-resources. In this paper, the current status of land use/landcover and the vegetation communities of the Solang valley watershed in Himachal Pradesh of Indian western Himalaya has been mapped and presented using remote sensing. This watershed area was dominated by alpine and sub-alpine pastures (30.34%) followed by scree slopes (22.34%) and forests (21.06%). Many tree, shrub, and herb species identified in the study area are among the prioritized species for conservation in the Indian Himalayan Region. Thus, scientific interventions and preparation of action plans based on ecological survey are required for conservation of the Solang valley watershed.
Huang, Ning; Wang, Hong Ying; Lin, Tao; Liu, Qi Ming; Huang, Yun Feng; Li, Jian Xiong
2016-10-01
Watershed landscape pattern regulation and optimization based on 'source-sink' theory for non-point source pollution control is a cost-effective measure and still in the exploratory stage. Taking whole watershed as the research object, on the basis of landscape ecology, related theories and existing research results, a regulation framework of watershed landscape pattern for non-point source pollution control was developed at two levels based on 'source-sink' theory in this study: 1) at watershed level: reasonable basic combination and spatial pattern of 'source-sink' landscape was analyzed, and then holistic regulation and optimization method of landscape pattern was constructed; 2) at landscape patch level: key 'source' landscape was taken as the focus of regulation and optimization. Firstly, four identification criteria of key 'source' landscape including landscape pollutant loading per unit area, landscape slope, long and narrow transfer 'source' landscape, pollutant loading per unit length of 'source' landscape along the riverbank were developed. Secondly, nine types of regulation and optimization methods for different key 'source' landscape in rural and urban areas were established, according to three regulation and optimization rules including 'sink' landscape inlay, banding 'sink' landscape supplement, pollutants capacity of original 'sink' landscape enhancement. Finally, the regulation framework was applied for the watershed of Maluan Bay in Xiamen City. Holistic regulation and optimization mode of watershed landscape pattern of Maluan Bay and key 'source' landscape regulation and optimization measures for the three zones were made, based on GIS technology, remote sensing images and DEM model.
Sparkman, Stephanie A.; Hogan, Dianna; Hopkins, Kristina G.; Loperfido, J. V.
2017-01-01
Stormwater runoff and associated pollutants from urban areas in the greater Chesapeake Bay Watershed (CBW) impair local streams and downstream ecosystems, despite urbanized land comprising only 7% of the CBW area. More recently, stormwater best management practices (BMPs) have been implemented in a low impact development (LID) manner to treat stormwater runoff closer to its source. This approach included the development of a novel BMP model to compare traditional and LID design, pioneering the use of comprehensively digitized storm sewer infrastructure and BMP design connectivity with spatial patterns in a geographic information system at the watershed scale. The goal was to compare total watershed pollutant removal efficiency in two study watersheds with differing spatial patterns of BMP design (traditional and LID), by quantifying the improved water quality benefit of LID BMP design. An estimate of uncertainty was included in the modeling framework by using ranges for BMP pollutant removal efficiencies that were based on the literature. Our model, using Monte Carlo analysis, predicted that the LID watershed removed approximately 78 kg more nitrogen, 3 kg more phosphorus, and 1,592 kg more sediment per square kilometer as compared with the traditional watershed on an annual basis. Our research provides planners a valuable model to prioritize watersheds for BMP design based on model results or in optimizing BMP selection.
NASA Astrophysics Data System (ADS)
Ahamed, A.; Snyder, N. P.; David, G. C.
2014-12-01
The Reservoir Sedimentation Database (ResSed), a catalogue of reservoirs and depositional data that has recently become publically available, allows for rapid calculation of sedimentation rates and rates of capacity loss over short (annual to decadal) timescales. This study is a statistical investigation of factors controlling watershed average erosion rates (E) in eastern United States watersheds. We develop an ArcGIS-based model that delineates watersheds upstream of ResSed dams and calculate drainage areas to determine E for 191 eastern US watersheds. Geomorphic, geologic, regional, climatic, and land use variables are quantified within study watersheds using GIS. Erosion rates exhibit a large amount of scatter, ranging from 0.001 to 1.25 mm/yr. A weak inverse power law relationship between drainage area (A) and E (R2 = 0.09) is evident, similar to other studies (e.g. Milliman and Syvitski, 1992; Koppes and Montgomery, 2009). Linear regressions reveal no relationship between mean watershed slope (S) and E, possibly due to the relatively low relief of the region (mean S for all watersheds is 6°). Analysis of Variance shows that watersheds in formerly glaciated regions exhibit a statistically significant lower mean E (0.06 mm/year) than watersheds in unglaciated regions (0.12 mm/year), but that watersheds with different dam purposes show no significant differences in mean E. Linear regressions reveal no relationships between E and land use parameters like percent agricultural land and percent impervious surfaces (I), but classification and regression trees indicate that watersheds in highly developed regions (I > 34%) exhibit mean E (0.36 mm/year) that is four times higher than watersheds in less developed (I < 34%) regions (0.09 mm/year). Further, interactions between land use variables emerge in formerly glaciated regions, where increased agricultural land results in higher rates of annual capacity loss in reservoirs (R2 = 0.56). Plots of E versus timescale of measurement (e.g., Sadler and Jerolmack, 2014) show that nearly the full range of observed E, including the highest values, are seen over short survey intervals (< 20 years), suggesting that whether or not large sedimentation events (such as floods) occur between two surveys may explain the high degree of variability in measured rates.
Holistic Watershed-Scale Approach for Studying Agricultural Chemicals
NASA Astrophysics Data System (ADS)
Capel, P. D.; Domagalski, J. L.
2006-05-01
The USGS National Water-Quality Assessment (NAWQA) Program studied the water quality of 51 areas across the United States during its first decade (1991-2001). Analyses of results from that phase of the NAWQA Program indicated that detailed studies of the processes affecting water quality could aid in the interpretation of these data, help to determine the direction and scope of future monitoring studies, and add to the understanding of the sources, transport and fate of non-point source chemicals, such as from agriculture. Now in the second decade of investigations, the NAWQA Program has initiated new process-based detailed studies to increase our understanding at the scale of a small watershed (about 3-15 square kilometers), nested within the larger basins studied during the first decade. The holistic, mass-budget approach for small agricultural watersheds that was adopted includes processes, and measures water and chemicals in the atmosphere, surface water, tile drains, overland flow, and within various sub-surface environments including the vadose, saturated, and hyporheic zones. The primary chemicals of interest were nutrients (nitrogen and phosphorous), the triazine and acetanilide herbicides, and the organophosphorus insecticides. Extensive field observations were made, and numerical models were developed to simulate important environmental compartments and interfaces associated with the transport and fate of agricultural chemicals. It is well recognized that these field measurements and simulations cannot fully achieve a full mass budget at this scale, but the approach provides a useful means for comparisons of various processes in different environmental settings. The results gained using this approach will add to the general knowledge of environmental transport and fate processes, and have transfer value to unstudied areas and different scales of investigation. The five initial study areas started in 2002, included watersheds in California, Indiana, Maryland, Nebraska and Washington. Two watersheds in Iowa and Mississippi were added in 2005. Each of these areas adopted the same general study design, but modified it slightly based on the local environmental setting. Consistent field and laboratory methods were used to enable direct comparison of results from each study area. This presentation of the study goals, design, and methods will serve as an introduction to other talks in this symposium.
Geospatial techniques for developing a sampling frame of watersheds across a region
Gresswell, Robert E.; Bateman, Douglas S.; Lienkaemper, George; Guy, T.J.
2004-01-01
Current land-management decisions that affect the persistence of native salmonids are often influenced by studies of individual sites that are selected based on judgment and convenience. Although this approach is useful for some purposes, extrapolating results to areas that were not sampled is statistically inappropriate because the sampling design is usually biased. Therefore, in recent investigations of coastal cutthroat trout (Oncorhynchus clarki clarki) located above natural barriers to anadromous salmonids, we used a methodology for extending the statistical scope of inference. The purpose of this paper is to apply geospatial tools to identify a population of watersheds and develop a probability-based sampling design for coastal cutthroat trout in western Oregon, USA. The population of mid-size watersheds (500-5800 ha) west of the Cascade Range divide was derived from watershed delineations based on digital elevation models. Because a database with locations of isolated populations of coastal cutthroat trout did not exist, a sampling frame of isolated watersheds containing cutthroat trout had to be developed. After the sampling frame of watersheds was established, isolated watersheds with coastal cutthroat trout were stratified by ecoregion and erosion potential based on dominant bedrock lithology (i.e., sedimentary and igneous). A stratified random sample of 60 watersheds was selected with proportional allocation in each stratum. By comparing watershed drainage areas of streams in the general population to those in the sampling frame and the resulting sample (n = 60), we were able to evaluate the how representative the subset of watersheds was in relation to the population of watersheds. Geospatial tools provided a relatively inexpensive means to generate the information necessary to develop a statistically robust, probability-based sampling design.
Quantifying stream channel sediment contributions for the Paradise Creek Watershed in northern Idaho
NASA Astrophysics Data System (ADS)
Rittenburg, R.; Squires, A.; Boll, J.; Brooks, E. S.
2012-12-01
Excess sediment from agricultural areas has been a major source of impairment for water bodies around the world, resulting in the implementation of mitigation measures across landscapes. Watershed scale reductions often target upland erosion as key non-point sources for sediment loading. Stream channel dynamics, however, also play a contributing role in sediment loading in the form of legacy sediments, channel erosion and deposition, and buffering during storm events. Little is known about in-stream contributions, a potentially important consideration for Total Maximum Daily Loads (TMDLs). The objective of this study is to identify where and when sediment is delivered to the stream and the spatial and temporal stream channel contributions to the overall watershed scale sediment load. The study area is the Paradise Creek Watershed in northern Idaho. We modeled sediment yield to the channel system using the Water Erosion Prediction Project (WEPP) model, and subsequent channel erosion and deposition using CONCEPTs. Field observations of cross-sections along the channel system over a 5-year period were collected to verify model simulations and to test the hypothesis that the watershed load was made up predominantly of legacy sediments. Our modeling study shows that stream channels contributed to 50% of the total annual sediment load for the basin, with a 19 year time lag between sediments entering the stream to leaving the watershed outlet. Observations from long-term data in the watershed will be presented to indicate if the main source of the sediment is from either rural and urban non-point sources or the channel system.
NASA Astrophysics Data System (ADS)
El Hassan, A.; Fares, A.; Risch, E.
2017-12-01
Rain resulting from Hurricane Harvey stated to spread into Harris County late in August 25 and continued until August 31 2017. This high intensity rainfall caused catastrophic flooding across the Greater Houston Area and south Texas. The objectives of this study are to use the USACE Gridded Surface Subsurface Hydrologic Analysis model (GSSHA) to: i) simulate the hydrology and hydraulics of Cypress Creek watershed and quantify the impact of hurricane Harvey on it; and ii) test potential mitigation measures, e.g., construction of a third surface reservoir on the flooding and hydrology of this watershed. Cypress Creek watershed area is 733 km2. Simulations were conducted using precipitation from two sources a) the Multisensory Precipitation Estimator radar products (MPE) and Multi-Radar Multi-Sensor (MRMS) system. Streamflow was downloaded from the USGS gauge at the outlet of the watershed. The models performance using both precipitation data was very reasonable. The construction of an 8 m high embankment at the south central part of the watershed resulted in over 22% reduction of the peak flow of the stream and also reduction of the depth of inundation across the east part of the watershed. These and other mitigation scenarios will be further discussed in details during the presentation.
Hydrological and hydraulic models for determination of flood-prone and flood inundation areas
NASA Astrophysics Data System (ADS)
Aksoy, Hafzullah; Sadan Ozgur Kirca, Veysel; Burgan, Halil Ibrahim; Kellecioglu, Dorukhan
2016-05-01
Geographic Information Systems (GIS) are widely used in most studies on water resources. Especially, when the topography and geomorphology of study area are considered, GIS can ease the work load. Detailed data should be used in this kind of studies. Because of, either the complication of the models or the requirement of highly detailed data, model outputs can be obtained fast only with a good optimization. The aim in this study, firstly, is to determine flood-prone areas in a watershed by using a hydrological model considering two wetness indexes; the topographical wetness index, and the SAGA (System for Automated Geoscientific Analyses) wetness index. The wetness indexes were obtained in the Quantum GIS (QGIS) software by using the Digital Elevation Model of the study area. Flood-prone areas are determined by considering the wetness index maps of the watershed. As the second stage of this study, a hydraulic model, HEC-RAS, was executed to determine flood inundation areas under different return period-flood events. River network cross-sections required for this study were derived from highly detailed digital elevation models by QGIS. Also river hydraulic parameters were used in the hydraulic model. Modelling technology used in this study is made of freely available open source softwares. Based on case studies performed on watersheds in Turkey, it is concluded that results of such studies can be used for taking precaution measures against life and monetary losses due to floods in urban areas particularly.
Jefferson, Anne J.; Bhaskar, Aditi S.; Hopkins, Kristina G.; Fanelli, Rosemary; Avellaneda, Pedro M.; McMillan, Sara K.
2017-01-01
Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small-scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention-based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non-additive effects of individual SCMs; and persistence of urban effects beyond impervious surfaces. In most cases, pollutant load decreases largely result from run-off reductions rather than lowered solute or particulate concentrations. Understanding interactions between natural and built landscapes, including stormwater management strategies, is critical for successfully managing detrimental impacts of stormwater at the watershed scale.
Hua, Lizhong; He, Xiubin; Yuan, Yongping; Nan, Hongwei
2012-05-01
Soil erosion has been recognized as one of the major threats to our environment and water quality worldwide, especially in China. To mitigate nonpoint source water quality problems caused by soil erosion, best management practices (BMPs) and/or conservation programs have been adopted. Watershed models, such as the Annualized Agricultural Non-Point Source Pollutant Loading model (AnnAGNPS), have been developed to aid in the evaluation of watershed response to watershed management practices. The model has been applied worldwide and proven to be a very effective tool in identifying the critical areas which had serious erosion, and in aiding in decision-making processes for adopting BMPs and/or conservation programs so that cost/benefit can be maximized and non-point source pollution control can be achieved in the most efficient way. The main goal of this study was to assess the characteristics of soil erosion, sediment and sediment delivery of a watershed so that effective conservation measures can be implemented. To achieve the overall objective of this study, all necessary data for the 4,184 km(2) Daning River watershed in the Three-Gorge region of the Yangtze River of China were assembled. The model was calibrated using observed monthly runoff from 1998 to 1999 (Nash-Sutcliffe coefficient of efficiency of 0.94 and R(2) of 0.94) and validated using the observed monthly runoff from 2003 to 2005 (Nash-Sutcliffe coefficient of efficiency of 0.93 and R(2) of 0.93). Additionally, the model was validated using annual average sediment of 2000-2002 (relative error of -0.34) and 2003-2004 (relative error of 0.18) at Wuxi station. Post validation simulation showed that approximately 48% of the watershed was under the soil loss tolerance released by the Ministry of Water Resources of China (500 t·km(-2)·y(-1)). However, 8% of the watershed had soil erosion of exceeding 5,000 t·km(-2)·y(-1). Sloping areas and low coverage areas are the main source of soil loss in the watershed.
Hua, Lizhong; He, Xiubin; Yuan, Yongping; Nan, Hongwei
2012-01-01
Soil erosion has been recognized as one of the major threats to our environment and water quality worldwide, especially in China. To mitigate nonpoint source water quality problems caused by soil erosion, best management practices (BMPs) and/or conservation programs have been adopted. Watershed models, such as the Annualized Agricultural Non-Point Source Pollutant Loading model (AnnAGNPS), have been developed to aid in the evaluation of watershed response to watershed management practices. The model has been applied worldwide and proven to be a very effective tool in identifying the critical areas which had serious erosion, and in aiding in decision-making processes for adopting BMPs and/or conservation programs so that cost/benefit can be maximized and non-point source pollution control can be achieved in the most efficient way. The main goal of this study was to assess the characteristics of soil erosion, sediment and sediment delivery of a watershed so that effective conservation measures can be implemented. To achieve the overall objective of this study, all necessary data for the 4,184 km2 Daning River watershed in the Three-Gorge region of the Yangtze River of China were assembled. The model was calibrated using observed monthly runoff from 1998 to 1999 (Nash-Sutcliffe coefficient of efficiency of 0.94 and R2 of 0.94) and validated using the observed monthly runoff from 2003 to 2005 (Nash-Sutcliffe coefficient of efficiency of 0.93 and R2 of 0.93). Additionally, the model was validated using annual average sediment of 2000–2002 (relative error of −0.34) and 2003–2004 (relative error of 0.18) at Wuxi station. Post validation simulation showed that approximately 48% of the watershed was under the soil loss tolerance released by the Ministry of Water Resources of China (500 t·km−2·y−1). However, 8% of the watershed had soil erosion of exceeding 5,000 t·km−2·y−1. Sloping areas and low coverage areas are the main source of soil loss in the watershed. PMID:22754480
Tsukada, Naoki; Katsumata, Masahiro; Oki, Koichi; Minami, Kazushi; Abe, Takato; Takahashi, Shinichi; Itoh, Yoshiaki; Suzuki, Norihiro
2018-01-15
A hemodynamic mechanism has long been assumed to play an important role in watershed infarction. In recent years, however, clinical evidence has indicated that an embolic mechanism is involved. The mechanism by which emboli are trapped preferentially in watershed areas remains unclear. In the present study, we developed a mouse embolus model using fluorescent microspheres with different diameters and evaluated the role of the microspheres' diameters in the generation of a watershed-patterned distribution. We injected fluorescent microspheres of four different diameters (i.e., 13, 24, 40, and 69 μm) into the internal carotid artery of C57BL/6 mice either (1) without ligation of the common carotid artery (normal perfusion pressure model: NPPM) or (2) with ligation of the common carotid artery (low perfusion pressure model: LPPM). Left common carotid artery ligation induced reductions in local cerebral blood flow in both the periphery and the core area of the left middle cerebral artery. A greater reduction in the border-zone area between the left anterior cerebral artery and the middle cerebral artery was also noted. After 24 h, the brains were removed and the distribution of the microspheres in the brain was evaluated using a fluorescence microscope. The 24-μm microspheres were distributed in the watershed area more frequently than the other microsphere sizes (P < .05, ANOVA followed by Tukey's test). Meanwhile, the distribution rates were similar between the NPPM and LPPM models for all microsphere sizes. This study suggested that the distribution pattern of the microspheres was only affected by the microspheres' diameters. Copyright © 2017 Elsevier B.V. All rights reserved.
Quantifying Groundwater Nutrient Discharge to a Large Glacial Lake using a Watershed Loading Model
NASA Astrophysics Data System (ADS)
Schilling, K. E.
2015-12-01
Groundwater discharge to a lake is an important, if often neglected, component to water and nutrient budgets. Point measurements of groundwater discharge into a lake are prone to error, so in this study of 15.57 km2 West Lake Okoboji, Iowa, a watershed-based groundwater loading model was developed. Located in northwest Iowa, West Lake Okoboji is considered one of Iowa's premier tourist destinations but is threatened by eutrophication. A network of 21 observation wells was installed in the watershed to evaluate groundwater recharge and quality under representative land cover types in a range of landscape positions. Our objective was to develop typical groundwater responses from various land cover-landscape associations for scaling up to unmonitored areas in the watershed. Results indicated substantial variation in groundwater recharge and quality in the 3847 ha watershed. Recharge was similar among land covers under vegetation but was much lower under urban pavement. Nitrate-nitrogen concentrations were highest under cropped fields and lowest under perennial grassland and golf courses, whereas dissolved phosphorus was highest under residential and urban areas, including an engineered bioswale. A groundwater load allocation model indicated 91% of the nitrate load was from cropped areas and 7% from residential areas. In contrast, P loads were more equally divided among cropped fields (43%), perennial grass (36%) and residential (19%) areas. Based on the mass of nitrate and P in the lake, groundwater accounts for 71% and 18% of the nutrient inputs, respectively.
Xie, Hui Jun; Li, Chong Wei; Zhang, Ya Juan; Song, Ai Yun
2016-04-22
Imperviousness in watershed is a key index to measure urbanization status which exerts an important impact on both eco-hydrological process and spatio-temporal pattern. Taking Yuqiao Reservoir Watershed as a case study area, based on the ENVI 5.1 software, the basic impervious surface information was extracted from remote sensing images taken in 1984, 1994, 2004 and 2013. The linear spectral mixture analysis (LSMA) model was applied to extract the impervious surface area (ISA) in nine coverage classes of watershed in order to analyze its spatio-temporal varying trend in terms of the landscape pattern metrics. Results showed that the RMSE and IS pixel accuracy of all samples were 0.005 and 85.4% respectively, which indicated that the method of extracting impervious surface on a basin scale was feasible. The average of ISA showed a linear growth, from 0.16 to 0.23, the impervious surface area increased by 4.9% in the whole watershed, and the total impervious surface area increased by 1 time. In the sub-basin road network, the impervious surface area increased gradually with the density of the road network, and its expansion pattern was of infilling growth. The patch shape of the middle coverage degree was irregular, and its fragmentation degree was the highest. The fragmentation degree and diversity of the landscape in the whole river basin increased year by year due to increasing human disturbance.
Prioritizing subwatersheds for stormwater pollution to Wachusett Reservoir.
Cho, Kyung Hwa; Park, Mi-Hyun
2013-02-01
The Wachusett Reservoir is a primary drinking water resource for the greater Boston, Massachusetts, area. With a drainage area of 280 km2, the watershed has been gradually urbanized with increased residential, commercial, industrial, and transportation land uses. Increased impervious surface area as a result of urbanization results in increased runoff volume and pollutant loads to the reservoir. This study estimated annual stormwater pollutant mass loads in the watershed to prioritize sub-basins and to identify areas susceptible to stormwater pollution. Catchment Prioritization Index (CPI) was calculated using annual stormwater pollutant mass loads, which were further used to identify clustered hotspots through application of the Getis-Ord Gi* statistic. Validation with observed data showed higher levels of fecal coliform bacteria loading from identified hotspots. This approach will be useful to prioritize sub-basins for future (1) development of stormwater monitoring strategies and (2) best management practices (BMPs) in the watershed.
NASA Astrophysics Data System (ADS)
Kivva, Sergei; Zheleznyak, Mark; Konoplev, Alexei; Nanba, Kenji; Onda, Yuichi; Wakiyama Yoshifumi Wakiyama, Yoshifumi
2015-04-01
The distributed hydrological "rainfall- runoff" models provide possibilities of the physically based simulation of surface and subsurface flow on watersheds based on the GIS processed data. The success of such modeling approaches for the predictions of the runoff and soil erosion provides a basis for the implementation of the distributed models of the radionuclide washoff from the watersheds. The field studies provided on the Chernobyl and Fukushima catchments provides a unique data sets for the comparative testing and improvements of the modeling tools for the watersheds located in the areas of the very different geographical and hydro-meteorological condition The set of USLE experimental plots has been established by CRIED, University of Tsukuba after the Fukushima accident to study soil erosion and 137Cs wash off from the watersheds (Onda et al, 2014). The distributed watershed models of surface and subsurface flow, sediment and radionuclide transport has been used to simulate the radionuclide transport in the basin Dnieper River, Ukraine and the watersheds of Prefecture Fuksuhima. DHSVM-R is extension of the distributed hydrological model DHSVM (Lettenmayer, Wigmosta et al, 1996-2014) by the including into it the module of the watershed radionuclide transport. DHSVM is a physically based, distributed hydrology-vegetation model for complex terrain based on the numerical solution of the network of one-dimensional equations. The surface flow submodel of DHSMV has been modified: four-directions schematization for the model's cells has been replaced by the eight-directions scheme, more numerically efficient finite -differences scheme was implemented. The new module of radionuclide wash-off from catchment and transport via stream network in soluble phase and on suspended sediments including bottom-water exchange processes was developed for DHSMV-R. DHSVM-R was implemented recently within Swedish- Ukrainian ENSURE project for the modeling of 234U wash-off from the watershed of Konoplyanka river, tributary of Dnieper Rivet at the territory of the Pridneprovsky Chemical) Plant and neighboring tailings dumps. The modeling results has been used for the assessment of the watershed's "hot spots" and analyses of the ways of the diminishing of the uranium wash off from the watersheds The testing of DHSMV-R has started in 2014 for Fukushima watershed experimental plots. The major amount of 137Cs is washed out from watershed on sediments and only small fraction in solute. The reason for such phenomenon that was not observed at Chernobyl can be - steeper slopes, more intensive rains ( daily maximum in Fukushima city at 160 mm, hourly maximum 69mm) and higher Kd values due to the volcanic kind of soils. The virtual rain of the daily amount 200 mm ( as in mountains around Fukushima city) was applied for Farmland A1- slope 7.36% and imaginary watershed (case B) the same as A1 however slope as in Chernobyl plots ( Konoplev, 1996) 4%. Due to the high nonlinearity in erosion equations for the such heavy precipitations the total amount of washed out 137Cs with sediments for the steep watershed A due to the simulated rainstorm ( 11530 Bq) is at 20 times higher, than such amount for mild slope watershed B ( 690 Bq) when the watershed A is only twice steeper than B. The modeling results demonstrate that the higher intensity of the extreme rainstorm in Fukushima area than in Chernobyl area initiated even on slightly steeper slopes the much higher amount of 137Cs washed out with sediments in Fukushima than in Chernobyl area. The successful testing of the distributed model provides the background for the simulation of the watersheds of the larger scales for small, medium and large rivers. The implementation of such models is important as for the forecasting of 137Cs wash out from the watersheds and following transport in rivers for the highest extreme floods that still did not happen in Fukushima area after the accident, as also for the long term forecasting of 137Cs in watershed-river systems at Fukushima.
Altaf, Sadaff; Meraj, Gowhar; Romshoo, Shakil Ahmad
2014-12-01
Complex mountainous environments such as Himalayas are highly susceptibility to natural hazards particular those that are triggered by the action of water such as floods, soil erosion, mass movements and siltation of the hydro-electric power dams. Among all the natural hazards, soil erosion is the most implicit and the devastating hazard affecting the life and property of the millions of people living in these regions. Hence to review and devise strategies to reduce the adverse impacts of soil erosion is of utmost importance to the planners of watershed management programs in these regions. This paper demonstrates the use of satellite based remote sensing data coupled with the observational field data in a multi-criteria analytical (MCA) framework to estimate the soil erosion susceptibility of the sub-watersheds of the Rembiara basin falling in the western Himalaya, using geographical information system (GIS). In this paper, watershed morphometry and land cover are used as an inputs to the MCA framework to prioritize the sub-watersheds of this basin on the basis of their different susceptibilities to soil erosion. Methodology included the derivation of a set of drainage and land cover parameters that act as the indicators of erosion susceptibility. Further the output from the MCA resulted in the categorization of the sub-watersheds into low, medium, high and very high erosion susceptibility classes. A detailed prioritization map for the susceptible sub-watersheds based on the combined role of land cover and morphometry is finally presented. Besides, maps identifying the susceptible sub-watersheds based on morphometry and land cover only are also presented. The results of this study are part of the watershed management program in the study area and are directed to instigate appropriate measures to alleviate the soil erosion in the study area.
Simulated wetland conservation-restoration effects on water quantity and quality at watershed scale.
Wang, Xixi; Shang, Shiyou; Qu, Zhongyi; Liu, Tingxi; Melesse, Assefa M; Yang, Wanhong
2010-07-01
Wetlands are one of the most important watershed microtopographic features that affect hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models such as the Soil and Water Assessment Tool (SWAT), enhanced by the hydrologic equivalent wetland (HEW) concept developed by Wang [Wang, X., Yang, W., Melesse, A.M., 2008. Using hydrologic equivalent wetland concept within SWAT to estimate streamflow in watersheds with numerous wetlands. Trans. ASABE 51 (1), 55-72.], can be a best resort. However, there is a serious lack of information about simulated effects using this kind of integrated modeling approach. The objective of this study was to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota. The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes and wetland characteristics (e.g., size and morphology) to be accurately represented in the models. The loss of the first 10-20% of the wetlands in the Minnesota study area would drastically increase the peak discharge and loadings of sediment, total phosphorus (TP), and total nitrogen (TN). On the other hand, the justifiable reductions of the peak discharge and loadings of sediment, TP, and TN in the Manitoba study area may require that 50-80% of the lost wetlands be restored. Further, the comparison between the predicted restoration and conservation effects revealed that wetland conservation seems to deserve a higher priority while both wetland conservation and restoration may be equally important. Copyright 2010 Elsevier Ltd. All rights reserved.
Sowah, Robert A; Habteselassie, Mussie Y; Radcliffe, David E; Bauske, Ellen; Risse, Mark
2017-01-01
The presence of multiple sources of fecal pollution at the watershed level presents challenges to efforts aimed at identifying the influence of septic systems. In this study multiple approaches including targeted sampling and monitoring of host-specific Bacteroidales markers were used to identify the impact of septic systems on microbial water quality. Twenty four watersheds with septic density ranging from 8 to 373 septic units/km 2 were monitored for water quality under baseflow conditions over a 3-year period. The levels of the human-associated HF183 marker, as well as total and ruminant Bacteroidales, were quantified using quantitative polymerase chain reaction. Human-associated Bacteroidales yield was significantly higher in high density watersheds compared to low density areas and was negatively correlated (r = -0.64) with the average distance of septic systems to streams in the spring season. The human marker was also positively correlated with the total Bacteroidales marker, suggesting that the human source input was a significant contributor to total fecal pollution in the study area. Multivariable regression analysis indicates that septic systems, along with forest cover, impervious area and specific conductance could explain up to 74% of the variation in human fecal pollution in the spring season. The results suggest septic system impact through contributions to groundwater recharge during baseflow or failing septic system input, especially in areas with >87 septic units/km 2 . This study supports the use of microbial source tracking approaches along with traditional fecal indicator bacteria monitoring and land use characterization in a tiered approach to isolate the influence of septic systems on water quality in mixed-use watersheds. Copyright © 2016 Elsevier Ltd. All rights reserved.
Chiu, Ming-Chih; Hunt, Lisa; Resh, Vincent H
2017-03-01
Limited studies have addressed how future climate-change scenarios may alter the effects of pesticides on biotic assemblages or the effects of exposures to repeated pulses of pesticide mixtures. We used reported pesticide-use data as input to a hydrological fate and transport model (Soil and Water Assessment Tool) under multiple climate-change scenarios to simulate spatiotemporal dynamics of pesticides mixtures in streams on a daily time-step in the Sacramento River watershed of California. We predicted that there will be increased pesticide application with warming across the watershed, especially in upstream areas. Using a statistical model describing the relationship between macroinvertebrate communities and pesticide dynamics, we found that compared to the baseline period of 1970-1999: (1) most climate-change scenarios predicted increased rainfall and warming across the watershed during 2070-2099; and (2) increasing pesticide contamination and increased impact on macroinvertebrates will likely occur in most areas of the watershed by 2070-2099; and (3) lower increases in effects of pesticides on macroinvertebrates were predicted for the downstream areas with intensive agriculture compared to some upstream areas with less-intensive agriculture. Future efforts on practical adaptation and mitigation strategies can be improved by awareness of altered threats of pesticide mixtures under future climate-change conditions. Copyright © 2017 Elsevier B.V. All rights reserved.
Aulenbach, Brent T.; Landers, Mark N.; Musser, Jonathan W.; Painter, Jaime A.
2017-01-01
The effects of increases in effective impervious area (EIA) and the implementation of water quality protection designed detention pond best management practices (BMPs) on storm runoff and stormwater quality were assessed in Gwinnett County, Georgia, for the period 2001-2008. Trends among eight small watersheds were compared, using a time trend study design. Significant trends were detected in three storm hydrologic metrics and in five water quality constituents that were adjusted for variability in storm characteristics and climate. Trends in EIA ranged from 0.10 to 1.35, and changes in EIA treated by BMPs ranged from 0.19 to 1.32; both expressed in units of percentage of drainage area per year. Trend relations indicated that for every 1% increase in watershed EIA, about 2.6, 1.1, and 1.5% increases in EIA treated by BMPs would be required to counteract the effects of EIA added to the watersheds on peak streamflow, stormwater yield, and storm streamflow runoff, respectively. Relations between trends in EIA, BMP implementation, and water quality were counterintuitive. This may be the result of (1) changes in constituent inputs in the watersheds, especially downstream of areas treated by BMPs; (2) BMPs may have increased the duration of stormflow that results in downstream channel erosion; and/or (3) spurious relationships between increases in EIA, BMP implementation, and constituent inputs with development rates.
NASA Astrophysics Data System (ADS)
Moore, J.; Bird, D. L.; Dobbis, S. K.; Woodward, G.
2016-12-01
Urban areas and associated impervious surface cover (ISC) are among the fastest growing land use types. Rapid growth of urban lands has significant implications for geochemical cycling and solute sources to streams, estuaries, and coastal waters. However, little work has been done to investigate the impacts of urbanization on Critical Processes, including on the export of solutes from urban watersheds. Despite observed elevated solute concentrations in urban streams in some previous studies, neither solute sources nor total solute fluxes have been quantified due to mixed bedrock geology, lack of a forested reference watershed, or the presence of point sources that confounded separation of anthropologic and natural sources. We investigated the geochemical signal of the urban built environment (e.g., roads, parking lots, buildings) in a set of five USGS-gaged watersheds across a rural (forested) to urban gradient in the Maryland Piedmont. These watersheds have ISC ranging from 0 to 25%, no point sources, and similar felsic bedrock chemistry. Weathering from the urban built environment and ISC produces dramatically higher solute concentrations in urban watersheds than in the forested watershed. Higher solute concentrations result in chemical weathering fluxes from urban watersheds that are 11-13 times higher than the forested watershed and are similar to fluxes from mountainous, weathering-limited watersheds rather than fluxes from transport-limited, dilute streams like the forested watershed. Weathering of concrete in urban watersheds produces geochemistry similar to weathering-limited watersheds with high concentrations of Ca2+, Mg2+, and DIC, which is similar to stream chemistry due to carbonate weathering. Road salt dissolution results in high Na+ and Cl- concentrations similar to evaporite weathering. Quantifying processes causing elevated solute fluxes from urban areas is essential to understanding cycling of Ca2+, Mg2+, and DIC in urban streams and in downgradient estuarine or coastal waters.
Protect and Restore Mill Creek Watershed; Annual Report 2004-2005.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2005-12-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership, more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. Starting in FY 2002, continuing intomore » 2004, trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-stream crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed, and one high priority culvert was replaced in 2004. Maintenance to the previously built fence was also completed.« less
Restore McComas Meadows; Meadow Creek Watershed, 2005-2006 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2006-07-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated and cost shared with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing, planting trees in riparian areas within the meadow and its tributaries, prioritizing culverts for replacement to accommodate fish passage, and decommissioning roads tomore » reduce sediment input. During this contract period work was completed on two culvert replacement projects; Doe Creek and a tributary to Meadow Creek. Additionally construction was also completed for the ditch restoration project within McComas Meadows. Monitoring for project effectiveness and trends in watershed conditions was also completed. Road decommissioning monitoring, as well as stream temperature, sediment, and discharge were completed.« less
Protect and Restore Mill Creek Watershed; Annual Report 2003-2004.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2004-06-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe and the Nez Perce National Forest have formed a partnership in completing watershed restoration activities, and through this partnership, more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. Starting in FY 2002, continuing into 2004,more » trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-stream crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed, and designs completed on two of the high priority culverts. Maintenance to the previously built fence was also completed.« less
Protect and Restore Mill Creek Watershed : Annual Report CY 2005.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2006-03-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership, more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Mill Creek watershed of the South Fork Clearwater River in 2000. Progress has been made in restoring the watershed through excluding cattle from critical riparian areas through fencing. Starting in FY 2002, continuing intomore » 2004, trees were planted in riparian areas in the meadow of the upper watershed. In addition, a complete inventory of culverts at road-stream crossings was completed. Culverts have been prioritized for replacement to accommodate fish passage throughout the watershed, and one high priority culvert was replaced in 2004. Maintenance to the previously built fence was also completed.« less
Targeting land-use change for nitratenitrogen load reductions in an agricultural watershed
Jha, M.K.; Schilling, K.E.; Gassman, Philip W.; Wolter, C.F.
2010-01-01
The research was conducted as part of the USDA's Conservation Effects Assessment Project. The objective of the project was to evaluate the environmental effects of land-use changes, with a focus on understanding how the spatial distribution throughout a watershed influences their effectiveness.The Soil and Water AssessmentTool (SWAT) water quality model was applied to the Squaw Creek watershed, which covers 4,730 ha (11,683 ac) of prime agriculture land in southern Iowa. The model was calibrated (2000 to 2004) and validated (1996 to 1999) for overall watershed hydrology and for streamflow and nitrate loadings at the watershed outlet on an annual and monthly basis. Four scenarios for land-use change were evaluated including one scenario consistent with recent land-use changes and three scenarios focused on land-use change on highly erodible land areas, upper basin areas, and floodplain areas. Results for the Squaw Creek watershed suggested that nitrate losses were sensitive to land-use change. If land-use patterns were restored to 1990 conditions, nitrate loads may be reduced 7% to 47% in the watershed and subbasins, whereas converting row crops to grass in highly erodible land, upper basin, and floodplain areas would reduce nitrate loads by 47%, 16%, and 8%, respectively. These SWAT model simulations can provide guidance on how to begin targeting land-use change for nitrate load reductions in agricultural watersheds.
NASA Astrophysics Data System (ADS)
Chou, Tien-Yin; Lin, Wen-Tzu; Lin, Chao-Yuan; Chou, Wen-Chieh; Huang, Pi-Hui
2004-02-01
With the fast growing progress of computer technologies, spatial information on watersheds such as flow direction, watershed boundaries and the drainage network can be automatically calculated or extracted from a digital elevation model (DEM). The stubborn problem that depressions exist in DEMs has been frequently encountered while extracting the spatial information of terrain. Several filling-up methods have been proposed for solving depressions. However, their suitability for large-scale flat areas is inadequate. This study proposes a depression watershed method coupled with the Preference Ranking Organization METHod for Enrichment Evaluations (PROMETHEEs) theory to determine the optimal outlet and calculate the flow direction in depressions. Three processing procedures are used to derive the depressionless flow direction: (1) calculating the incipient flow direction; (2) establishing the depression watershed by tracing the upstream drainage area and determining the depression outlet using PROMETHEE theory; (3) calculating the depressionless flow direction. The developed method was used to delineate the Shihmen Reservoir watershed located in Northern Taiwan. The results show that the depression watershed method can effectively solve the shortcomings such as depression outlet differentiating and looped flow direction between depressions. The suitability of the proposed approach was verified.
ERIC Educational Resources Information Center
Chanse, Victoria; Mohamed, Amina; Wilson, Sacoby; Dalemarre, Laura; Leisnham, Paul T.; Rockler, Amanda; Shirmohammadi, Adel; Montas, Hubert
2017-01-01
In urbanized areas, incorporating residents' concerns and priorities into the stormwater management debate has focused on adults rather than youth. This study used Photovoice, a tool that includes photographs taken by youth, to uncover youth concerns and perceptions about their local watersheds. This study consisted of a comparative study of two…
Niraula, Rewati; Norman, Laura A.; Meixner, Thomas; Callegary, James B.
2012-01-01
In most watershed-modeling studies, flow is calibrated at one monitoring site, usually at the watershed outlet. Like many arid and semi-arid watersheds, the main reach of the Santa Cruz watershed, located on the Arizona-Mexico border, is discontinuous for most of the year except during large flood events, and therefore the flow characteristics at the outlet do not represent the entire watershed. Calibration is required at multiple locations along the Santa Cruz River to improve model reliability. The objective of this study was to best portray surface water flow in this semiarid watershed and evaluate the effect of multi-gage calibration on flow predictions. In this study, the Soil and Water Assessment Tool (SWAT) was calibrated at seven monitoring stations, which improved model performance and increased the reliability of flow, in the Santa Cruz watershed. The most sensitive parameters to affect flow were found to be curve number (CN2), soil evaporation and compensation coefficient (ESCO), threshold water depth in shallow aquifer for return flow to occur (GWQMN), base flow alpha factor (Alpha_Bf), and effective hydraulic conductivity of the soil layer (Ch_K2). In comparison, when the model was established with a single calibration at the watershed outlet, flow predictions at other monitoring gages were inaccurate. This study emphasizes the importance of multi-gage calibration to develop a reliable watershed model in arid and semiarid environments. The developed model, with further calibration of water quality parameters will be an integral part of the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM), an online decision support tool, to assess the impacts of climate change and urban growth in the Santa Cruz watershed.
Evaldi, Ronald D.; Paybins, Katherine S.; Kozar, Mark D.
2009-01-01
Base-flow yields at approximately the annual 75-percent-duration flow were determined for watersheds in the Jefferson County area, WV, from stream-discharge measurements made during October 31 to November 2, 2007. Five discharge measurements of Opequon Creek defined increased flow from 29,000,000 gallons per day (gal/d) at Carters Ford to 51,400,000 gal/d near Vanville. No flow was observed at 45 of 110 additional stream sites inspected, and discharge at the 65 flowing stream sites ranged from 1,940 to 17,100,000 gallons per day (gal/d). Discharge at 28 springs ranged from no flow to 2,430,000 gal/d. Base-flow yields were computed as the change in stream-channel discharge between measurement sites divided by the change in drainage area between the sites. Yields were negative for losing (influent) channel reaches and positive for gaining (effluent) reaches. Channels in 14 watersheds were determined to have lost flow ranging from -9.6 to -1,770 gallons per day per acre (gal/d/acre). Channels in 51 watersheds were determined to have gained flow ranging from 3.4 to 235,000 gal/d/acre. Water temperature at the stream sites ranged from 5.0 to 16.3 deg C (quarry pumpage), and specific conductance ranged from 51 to 881 microsiemens per centimeter (uS/cm). Water temperature at the springs ranged from 11.5 to 15.0 deg C, and specific conductance ranged from 22 to 958 uS/cm. Large springs in some watersheds in western Jefferson County are adjacent to other watersheds with little or no surface-water discharge; this is probably the result of interbasin transfer of groundwater along faults that dissect the area. Most watersheds located adjacent to the Potomac River in northeastern Jefferson County were not flowing during this study; this is most likely because the Potomac River is deeply incised, and groundwater flows directly to it rather than to the local stream systems in these areas. Except for one watershed with a yield of 651 gal/d/acre, no watersheds in northeastern Jefferson County yielded more than 305 gal/d/acre. Base-flow yields of several watersheds in south-central Jefferson County exceeded 400 gal/d/acre, and the effect of the Shenadoah River on base flows in the watershed appears to be less than that of the Potomac River in the northeastern part of the county. In the southeastern part of the county, because of steep relief and low-permeability bedrock, several streams were not flowing at the time of the study, and yields from all flowing streams were all less than 100 gal/d/acre. On the basis of historical data from 1961 through 2008, the mean and median depths to groundwater in 213 wells in western Jefferson County were 33.4 and 29.3 ft, respectively. Mean and median depths to groundwater in 69 wells in the northeastern county area were 56.0 and 55.0 ft below land surface, respectively. However, mean and median depths to groundwater in 28 wells within 1.5 miles of the Potomac River were 70.0 and 71.3 ft below land surface, respectively. Mean and median depths to groundwater in 108 wells in the south-central county area were 53.9 and 52.8 ft below land surface, respectively. Mean and median depths to groundwater of 26 wells in the southeastern county area were 86.6 and 59.5 ft below land surface, respectively.
Asquith, William H.; Cleveland, Theodore G.; Roussel, Meghan C.
2011-01-01
Estimates of peak and time of peak streamflow for small watersheds (less than about 640 acres) in a suburban to urban, low-slope setting are needed for drainage design that is cost-effective and risk-mitigated. During 2007-10, the U.S. Geological Survey (USGS), in cooperation with the Harris County Flood Control District and the Texas Department of Transportation, developed a method to estimate peak and time of peak streamflow from excess rainfall for 10- to 640-acre watersheds in the Houston, Texas, metropolitan area. To develop the method, 24 watersheds in the study area with drainage areas less than about 3.5 square miles (2,240 acres) and with concomitant rainfall and runoff data were selected. The method is based on conjunctive analysis of rainfall and runoff data in the context of the unit hydrograph method and the rational method. For the unit hydrograph analysis, a gamma distribution model of unit hydrograph shape (a gamma unit hydrograph) was chosen and parameters estimated through matching of modeled peak and time of peak streamflow to observed values on a storm-by-storm basis. Watershed mean or watershed-specific values of peak and time to peak ("time to peak" is a parameter of the gamma unit hydrograph and is distinct from "time of peak") of the gamma unit hydrograph were computed. Two regression equations to estimate peak and time to peak of the gamma unit hydrograph that are based on watershed characteristics of drainage area and basin-development factor (BDF) were developed. For the rational method analysis, a lag time (time-R), volumetric runoff coefficient, and runoff coefficient were computed on a storm-by-storm basis. Watershed-specific values of these three metrics were computed. A regression equation to estimate time-R based on drainage area and BDF was developed. Overall arithmetic means of volumetric runoff coefficient (0.41 dimensionless) and runoff coefficient (0.25 dimensionless) for the 24 watersheds were used to express the rational method in terms of excess rainfall (the excess rational method). Both the unit hydrograph method and excess rational method are shown to provide similar estimates of peak and time of peak streamflow. The results from the two methods can be combined by using arithmetic means. A nomograph is provided that shows the respective relations between the arithmetic-mean peak and time of peak streamflow to drainage areas ranging from 10 to 640 acres. The nomograph also shows the respective relations for selected BDF ranging from undeveloped to fully developed conditions. The nomograph represents the peak streamflow for 1 inch of excess rainfall based on drainage area and BDF; the peak streamflow for design storms from the nomograph can be multiplied by the excess rainfall to estimate peak streamflow. Time of peak streamflow is readily obtained from the nomograph. Therefore, given excess rainfall values derived from watershed-loss models, which are beyond the scope of this report, the nomograph represents a method for estimating peak and time of peak streamflow for applicable watersheds in the Houston metropolitan area. Lastly, analysis of the relative influence of BDF on peak streamflow is provided, and the results indicate a 0:04log10 cubic feet per second change of peak streamflow per positive unit of change in BDF. This relative change can be used to adjust peak streamflow from the method or other hydrologic methods for a given BDF to other BDF values; example computations are provided.
NASA Astrophysics Data System (ADS)
Rittenburg, R.; Boll, J.; Brooks, E. S.
2013-12-01
Excess sediment from agricultural areas has been a major source of impairment for water bodies, resulting in the implementation of mitigation measures across landscapes. Watershed scale reductions often target upland erosion as key non-point sources for sediment loading. Stream channel dynamics, however, also play a contributing role in sediment loading in the form of legacy sediments, channel erosion and deposition, and buffering during storm events. In-stream contributions are not well understood, and are a potentially important consideration for Total Maximum Daily Loads (TMDLs). The objective of this study is to differentiate stream bank and stream bed sediment contributions and better understand the role of legacy sediments. The study area is the Paradise Creek Watershed in northern Idaho. We modeled sediment yield to the channel system using the Water Erosion Prediction Project (WEPP) model, and subsequent channel erosion and deposition using CONCEPTs. Field observations of cross-sections along the channel system over a 5-year period were collected to verify model simulations and to test the hypothesis that the watershed load was composed predominantly of legacy sediments. Our modeling study shows that stream channels contributed to 39% of the total annual sediment load for the basin, with a 19-year time lag between sediments entering the stream to leaving the watershed outlet. Observations from long-term cross sectional data in the watershed, and a sediment fingerprinting analysis will be presented to better understand sediment contributions from within the stream channel system.
NASA Astrophysics Data System (ADS)
Tarigan, Suria; Wiegand, Kerstin; Sunarti; Slamet, Bejo
2018-01-01
In many tropical regions, the rapid expansion of monoculture plantations has led to a sharp decline in forest cover, potentially degrading the ability of watersheds to regulate water flow. Therefore, regional planners need to determine the minimum proportion of forest cover that is required to support adequate ecosystem services in these watersheds. However, to date, there has been little research on this issue, particularly in tropical areas where monoculture plantations are expanding at an alarming rate. Therefore, in this study, we investigated the influence of forest cover and oil palm (Elaeis guineensis) and rubber (Hevea brasiliensis) plantations on the partitioning of rainfall into direct runoff and subsurface flow in a humid, tropical watershed in Jambi Province, Indonesia. To do this, we simulated streamflow with a calibrated Soil and Water Assessment Tool (SWAT) model and observed several watersheds to derive the direct runoff coefficient (C) and baseflow index (BFI). The model had a strong performance, with Nash-Sutcliffe efficiency values of 0.80-0.88 (calibration) and 0.80-0.85 (validation) and percent bias values of -2.9-1.2 (calibration) and 7.0-11.9 (validation). We found that the percentage of forest cover in a watershed was significantly negatively correlated with C and significantly positively correlated with BFI, whereas the rubber and oil palm plantation cover showed the opposite pattern. Our findings also suggested that at least 30 % of the forest cover was required in the study area for sustainable ecosystem services. This study provides new adjusted crop parameter values for monoculture plantations, particularly those that control surface runoff and baseflow processes, and it also describes the quantitative association between forest cover and flow indicators in a watershed, which will help regional planners in determining the minimum proportion of forest and the maximum proportion of plantation to ensure that a watershed can provide adequate ecosystem services.
Sensitivity of Regional Hydropower Generation to the Projected Changes in Future Watershed Hydrology
NASA Astrophysics Data System (ADS)
Kao, S. C.; Naz, B. S.; Gangrade, S.
2015-12-01
Hydropower is a key contributor to the renewable energy portfolio due to its established development history and the diverse benefits it provides to the electric power systems. With the projected change in the future watershed hydrology, including shift of snowmelt timing, increasing occurrence of extreme precipitation, and change in drought frequencies, there is a need to investigate how the regional hydropower generation may change correspondingly. To evaluate the sensitivity of watershed storage and hydropower generation to future climate change, a lumped Watershed Runoff-Energy Storage (WRES) model is developed to simulate the annual and seasonal hydropower generation at various hydropower areas in the United States. For each hydropower study area, the WRES model use the monthly precipitation and naturalized (unregulated) runoff as inputs to perform a runoff mass balance calculation for the total monthly runoff storage in all reservoirs and retention facilities in the watershed, and simulate the monthly regulated runoff release and hydropower generation through the system. The WRES model is developed and calibrated using the historic (1980-2009) monthly precipitation, runoff, and generation data, and then driven by a large set of dynamically- and statistically-downscaled Coupled Model Intercomparison Project Phase 5 climate projections to simulate the change of watershed storage and hydropower generation under different future climate scenarios. The results among different hydropower regions, storage capacities, emission scenarios, and timescales are compared and discussed in this study.
Slonecker, Terry E.; Milheim, Lesley E.
2015-01-01
The spatial footprint of unconventional (hydraulic fracturing) and conventional oil and gas development in the Marcellus Shale region of the State of Pennsylvania was digitized from high-resolution, ortho-rectified, digital aerial photography, from 2004 to 2010. We used these data to measure the spatial extent of oil and gas development and to assess the exposure of the extant natural resources across the landscape of the watersheds in the study area. We found that either form of development: (1) occurred in ~50% of the 930 watersheds that defined the study area; (2) was closer to streams than the recommended safe distance in ~50% of the watersheds; (3) was in some places closer to impaired streams and state-defined wildland trout streams than the recommended safe distance; (4) was within 10 upstream kilometers of surface drinking water intakes in ~45% of the watersheds that had surface drinking water intakes; (5) occurred in ~10% of state-defined exceptional value watersheds; (6) occurred in ~30% of the watersheds with resident populations defined as disproportionately exposed to pollutants; (7) tended to occur at interior forest locations; and (8) had >100 residents within 3 km for ~30% of the unconventional oil and gas development sites. Further, we found that exposure to the potential effects of landscape disturbance attributable to conventional oil and gas development was more prevalent than its unconventional counterpart.
Distributed watershed modeling of design storms to identify nonpoint source loading areas
DOE Office of Scientific and Technical Information (OSTI.GOV)
Endreny, T.A.; Wood, E.F.
1999-03-01
Watershed areas that generate nonpoint source (NPS) polluted runoff need to be identified prior to the design of basin-wide water quality projects. Current watershed-scale NPS models lack a variable source area (VSA) hydrology routine, and are therefore unable to identify spatially dynamic runoff zones. The TOPLATS model used a watertable-driven VSA hydrology routine to identify runoff zones in a 17.5 km{sup 2} agricultural watershed in central Oklahoma. Runoff areas were identified in a static modeling framework as a function of prestorm watertable depth and also in a dynamic modeling framework by simulating basin response to 2, 10, and 25 yrmore » return period 6 h design storms. Variable source area expansion occurred throughout the duration of each 6 h storm and total runoff area increased with design storm intensity. Basin-average runoff rates of 1 mm h{sup {minus}1} provided little insight into runoff extremes while the spatially distributed analysis identified saturation excess zones with runoff rates equaling effective precipitation. The intersection of agricultural landcover areas with these saturation excess runoff zones targeted the priority potential NPS runoff zones that should be validated with field visits. These intersected areas, labeled as potential NPS runoff zones, were mapped within the watershed to demonstrate spatial analysis options available in TOPLATS for managing complex distributions of watershed runoff. TOPLATS concepts in spatial saturation excess runoff modelling should be incorporated into NPS management models.« less
Physical characterization of a watershed through GIS: a study in the Schmidt stream, Brazil.
Reis, D R; Plangg, R; Tundisi, J G; Quevedo, D M
2015-12-01
Remote sensing and geoprocessing are essential tools for obtaining and maintaining records of human actions on space over the course of time; these tools offer the basis for diagnoses of land use, environmental interference and local development. The Schmidt stream watershed, located in the Sinos River basin, in southern Brazil, has an environmental situation similar to that of the majority of small streams draining rural and urban areas in southern Brazil: agricultural and urbanization practices do not recognize the riparian area and there is removal of original vegetation, disregarding the suitability of land use; removal of wetlands; intensive water use for various activities; and lack of control and monitoring in the discharge of wastewater, among other factors, deteriorate the quality of this important environment.This article aims to achieve a physical characterization of the Schmidt stream watershed (Sinos river basin) identifying elements such as land use and occupation, soil science, geology, climatology, extent and location of watershed, among others, so as to serve as the basis for a tool that helps in the integrated environmental management of watersheds. By applying geographic information system - GIS to the process of obtaining maps of land use and occupation, pedologicaland geological, and using climatological data from the Campo Bom meteorological station, field visit, review of literature and journals, and publicly available data, the physical characterization of the Schmidt stream watershed was performed, with a view to the integrated environmental management of this watershed. Out of the total area of the Schmidt stream watershed (23.92 km(2)), in terms of geology, it was observed that 23.7% consist of colluvial deposits, 22.6% consist of grass facies, and 53.7% consist of Botucatu formation. Major soil types of the watershed: 97.4% Argisols and only 2.6% Planosols. Land use and occupation is characterized by wetland (0.5%), Native Forest (12.83%), Native Forest + Rural Anthropic + Secondary Vegetation + Forestry (43.81%), Urban Anthropic/Urban Area (39.85%), and also Urban Anthropic/Expansion areas (3.01%). Mean annual rainfall is 1337 mm, maximum temperatures range from 10.5°C to 41.6°C and minimum temperatures range from -1.80°C and 26°C, weak winds, occasionally over 5 m/s. Conducting an environmental assessment in this watershed is essential for environmental and land management. However, these assessments are not conducted in all watersheds and, when they are, their frequency is not sufficiency to allow for continuous monitoring, in order to model and predict scenarios, with a view to adopt medium and long-term measures for environmental protection.
Compilation of hydrologic data, Little Elm Creek, Trinity River basin, Texas, 1968
,
1972-01-01
The U.S. Soil Conservation Service is actively engaged in the installation of flood and soil erosion reducing measures in Texas under the authority of "The Flood Control Act ot 1936 and 1944" and ''Watershed Protection and Flood Prevention Act" (Public Law 566), as amended. In June 1968, the Soil Conservation Service estimated approximately 3,500 structures to be physically and economically feasible for installation in Texas. As of September 30, 1968, 1,271 of these structures had been built. This watershed-development program will have varying but important effects on the surface- and ground-water resources of river basins, especially where a large number of the floodwater-retarding structures are built. Basic hydrologic data are needed to appraise the effects of the structures on water yield and the mode of occurrence of runoff. Hydrologic investigations of these small watersheds were begun by the Geological Survey in 1951 and are now being made in 11 areas (fig. 1). These studies are being made in cooperation with t he Texas Water Development Board, the Soil Conservation Service, the San Antonio River Authority, the city of Dallas, and the Tarrant County Water Control and Improvement District No. 1. The 11 study areas were choson to sample watersheds having different rainfall, topography, geology, and soils. In four of the study areas (Mukewater, North, Little Elm, and Pin Oak Creeks), streamflow and rainfall records were collected prior to construction of the floodwater-retarding structures, thus affording the opportunity for analyses to the conditions before and after" development. Structures have now been built in three of these study areas. A summary of the development of the floodwater-retarding structures on each study area as of September 30, 1968, is shown in table 1.
Brandt-Williams, Sherry; Wigand, Cathleen; Campbell, Daniel E
2013-02-01
This study evaluated the link between watershed activities and salt marsh structure, function, and condition using spatial emergy flow density (areal empower density) in the watershed and field data from 10 tidal salt marshes in Narragansett Bay, RI, USA. The field-collected data were obtained during several years of vegetation, invertebrate, soil, and water quality sampling. The use of emergy as an accounting mechanism allowed disparate factors (e.g., the amount of building construction and the consumption of electricity) to be combined into a single landscape index while retaining a uniform quantitative definition of the intensity of landscape development. It expanded upon typical land use percentage studies by weighting each category for the intensity of development. At the RI salt marsh sites, an impact index (watershed emergy flow normalized for marsh area) showed significant correlations with mudflat infauna species richness, mussel density, plant species richness, the extent and density of dominant plant species, and denitrification potential within the high salt marsh. Over the 4-year period examined, a loading index (watershed emergy flow normalized for watershed area) showed significant correlations with nitrite and nitrate concentrations, as well as with the nitrogen to phosphorus ratios in stream discharge into the marshes. Both the emergy impact and loading indices were significantly correlated with a salt marsh condition index derived from intensive field-based assessments. Comparison of the emergy indices to calculated nitrogen loading estimates for each watershed also produced significant positive correlations. These results suggest that watershed emergy flow is a robust index of human disturbance and a potential tool for rapid assessment of coastal wetland condition.
NASA Astrophysics Data System (ADS)
Meierdiercks, K. L.; Smith, J. A.; Miller, A. J.
2006-12-01
The impact of urban development on watershed-scale hydrology is examined in a small urban watershed in the Metropolitan Baltimore area. Analyses focus on Dead Run, a 14.3 km2 tributary of the Gwynns Falls, which is the principal study watershed of the Baltimore Ecosystem Study. Field observations of rainfall and discharge have been collected for storms occurring in the 2003, 2004, and 2005 warm seasons including the flood of record for the USGS Dead Run at Franklintown gage (7 July 2004), in which 5 inches of rain fell in less than 4 hours. Dead Run has stream gages at 6 locations with drainage areas ranging from 1.2 to 14.3 km2. Hydrologic response to storm events varies greatly in each of the subwatersheds due to the diverse development types located there. These subwatersheds range in land use from medium-density residential, with and without stormwater management control, to commercial/light industrial with large impervious lots and an extensive network of stormwater management ponds. The unique response of each subwatershed is captured using field observations in conjunction with the EPA Stormwater Management Model (SWMM), which routes storm runoff over the land surface and through the drainage network of a watershed. Of particular importance to flood response is the structure of the drainage network (both surface channels and storm drain network) and its connectivity to preferential flow paths within the watershed. The Dead Run drainage network has been delineated using geospatial data derived from aerial photography and engineering planning drawings. Model analyses are used to examine the characteristics of flow paths that control flood response in urban watersheds. These analyses aim to identify patterns in urban flow pathways and use those patterns to predict response in other urban watersheds.
Integrating socio-economic and biophysical data to enhance watershed management and planning
NASA Astrophysics Data System (ADS)
Pirani, Farshad Jalili; Mousavi, Seyed Alireza
2016-09-01
Sustainability has always been considered as one of the main aspects of watershed management plans. In many developing countries, watershed management practices and planning are usually performed by integrating biophysical layers, and other existing layers which cannot be identified as geographic layers are ignored. We introduce an approach to consider some socioeconomic parameters which are important for watershed management decisions. Ganj basin in Chaharmahal-Bakhtiari Province was selected as the case study area, which includes three traditional sanctums: Ganj, Shiremard and Gerdabe Olya. Socioeconomic data including net agricultural income, net ranching income, population and household number, literacy rate, unemployment rate, population growth rate and active population were mapped within traditional sanctums and then were integrated into other biophysical layers. After overlaying and processing these data to determine management units, different quantitative and qualitative approaches were adopted to achieve a practical framework for watershed management planning and relevant plans for homogeneous units were afterwards proposed. Comparing the results with current plans, the area of allocated lands to different proposed operations considering both qualitative and quantitative approaches were the same in many cases and there was a meaningful difference with current plans; e.g., 3820 ha of lands are currently managed under an enclosure plan, while qualitative and quantitative approaches in this study suggest 1388 and 1428 ha to be allocated to this operation type, respectively. Findings show that despite the ambiguities and complexities, different techniques could be adopted to incorporate socioeconomic conditions in watershed management plans. This introductory approach will help to enhance watershed management decisions with more attention to societal background and economic conditions, which will presumably motivate local communities to participate in watershed management plans.
Lin, Chao-Yuan; Fu, Kuei-Lin; Lin, Cheng-Yu
2016-11-01
Recent extreme rainfall events led to many landslides due to climate changes in Taiwan. How to effectively promote post-disaster treatment and/or management works in a watershed/drainage basin is a crucial issue. Regarding the processes of watershed treatment and/or management works, disaster hotspot scanning and treatment priority setup should be carried out in advance. A scanning method using landslide ratio to determine the appropriate outlet of an interested watershed, and an optimal subdivision system with better homogeneity and accuracy in landslide ratio estimation were developed to help efficient executions of treatment and/or management works. Topography is a key factor affecting watershed landslide ratio. Considering the complexity and uncertainty of the natural phenomenon, multivariate analysis was applied to understand the relationship between topographic factors and landslide ratio in the interested watershed. The concept of species-area curve, which is usually adopted at on-site vegetation investigation to determinate the suitable quadrate size, was used to derive the optimal threshold in subdivisions. Results show that three main component axes including factors of scale, network and shape extracted from Digital Terrain Model coupled with areas of landslide can effectively explain the characteristics of landslide ratio in the interested watershed, and a relation curve obtained from the accuracy of landslide ratio classification and number of subdivisions could be established to derive optimal subdivision of the watershed. The subdivision method promoted in this study could be further used for priority rank and benefit assessment of landslide treatment in a watershed.
NASA Astrophysics Data System (ADS)
Galván, L.; Olías, M.; Cánovas, C. R.; Sarmiento, A. M.; Nieto, J. M.
2016-09-01
The Odiel watershed drains materials belonging to the Iberian Pyrite Belt, where significant massive sulfide deposits have been mined historically. As a result, a huge amount of sulfide-rich wastes are deposited in the watershed, which suffer from oxidation, releasing acidic lixiviates with high sulfate and metal concentrations. In order to reliably estimate the metal loadings along the watershed a complete series of discharge and hydrochemical data are essential. A hydrological model was performed with SWAT (Soil and Water Assessment Tool) to solve the scarcity of gauge stations along the watershed. The model was calibrated and validated from daily discharge data (from 1980 to 2010) at the outlet of the watershed, river inputs into an existent reservoir, and a flow gauge station close to the northern area of the watershed. Discharge data obtained from the hydrological model, together with analytical data, allowed the estimation of the dissolved pollutant load delivered annually by the Odiel River (e.g. 9140 t of Al, 2760 t of Zn). The pollutant load is influenced strongly by the rainfall regime, and can even double during extremely rainy years. Around 50% of total pollution comes from the Riotinto Mining District, so the treatment of Riotinto lixiviates reaching the Odiel watershed would reduce the AMD (Acid Mine Drainages) in a remarkable way, improving the water quality downstream, especially in the reservoir of Alcolea, currently under construction. The information obtained in this study will allow the optimization of remediation efforts in the watershed, in order to improve its water quality.
NASA Astrophysics Data System (ADS)
Lin, Chao-Yuan; Fu, Kuei-Lin; Lin, Cheng-Yu
2016-11-01
Recent extreme rainfall events led to many landslides due to climate changes in Taiwan. How to effectively promote post-disaster treatment and/or management works in a watershed/drainage basin is a crucial issue. Regarding the processes of watershed treatment and/or management works, disaster hotspot scanning and treatment priority setup should be carried out in advance. A scanning method using landslide ratio to determine the appropriate outlet of an interested watershed, and an optimal subdivision system with better homogeneity and accuracy in landslide ratio estimation were developed to help efficient executions of treatment and/or management works. Topography is a key factor affecting watershed landslide ratio. Considering the complexity and uncertainty of the natural phenomenon, multivariate analysis was applied to understand the relationship between topographic factors and landslide ratio in the interested watershed. The concept of species-area curve, which is usually adopted at on-site vegetation investigation to determinate the suitable quadrate size, was used to derive the optimal threshold in subdivisions. Results show that three main component axes including factors of scale, network and shape extracted from Digital Terrain Model coupled with areas of landslide can effectively explain the characteristics of landslide ratio in the interested watershed, and a relation curve obtained from the accuracy of landslide ratio classification and number of subdivisions could be established to derive optimal subdivision of the watershed. The subdivision method promoted in this study could be further used for priority rank and benefit assessment of landslide treatment in a watershed.
Design and Implementation of a Research-Informed Water Conservation Education Program
ERIC Educational Resources Information Center
Thompson, Ruthanne; Coe, Alice; Klaver, Irene; Dickson, Kenneth
2011-01-01
Informed by the results of a baseline research study of regional citizen knowledge and understanding concerning watershed issues, a team of university faculty and classroom teachers designed and implemented a water conservation education program to address lacking areas of watershed knowledge. The authors developed age-appropriate, hands-on…
Rodrigues-Filho, J L; Degani, R M; Soares, F S; Periotto, N A; Blanco, F P; Abe, D S; Matsumura-Tundisi, T; Tundisi, J E; Tundisi, J G
2015-01-01
The amendments to the Forest Law proposed by the Brazilian government that allow partial substitution of forested areas by agricultural activities raised deep concern about the integrity of aquatic ecosystems. To assess the impacts of this alteration in land uses on the watershed, diffuse loads of total nitrogen (Nt) and total phosphorus (Pt) were estimated in Lobo Stream watershed, southeastern Brazil, based on export coefficients of the Model of Correlation between Land Use and Water Quality (MQUAL). Three scenarios were generated: scenario 1 (present scenario), with 30-meter-wide permanent preservation areas along the shore of water bodies and 50-meter-radius in springs; scenario 2, conservative, with 100-meter-wide permanent preservation areas along water bodies; and scenario 3, with the substitution of 20% of natural forest by agricultural activities. Results indicate that a suppression of 20% of forest cover would cause an increase in nutrient loads as well as in the trophic state of aquatic ecosystems of the watershed. This could result in losses of ecosystem services and compromise the quality of water and its supply for the basin. This study underlines the importance of forest cover for the maintenance of water quality in Lobo Stream watershed.
Spatial Scaling of Floods in Atlantic Coastal Watersheds
NASA Astrophysics Data System (ADS)
Plank, C.
2013-12-01
Climate and land use changes are altering global, regional and local hydrologic cycles. As a result, past events may not accurately represent the events that will occur in the future. Methods for hydrologic prediction, both statistical and deterministic, require adequate data for calibration. Streamflow gauges tend to be located on large rivers. As a result, statistical flood frequency analysis, which relies on gauge data, is biased towards large watersheds. Conversely, the complexity of parameterizing watershed processes in deterministic hydrological models limits these to small watersheds. Spatial scaling relationships between drainage basin area and discharge can be used to bridge these two methodologies and provide new approaches to hydrologic prediction. The relationship of discharge (Q) to drainage basin area (A) can be expressed as a power function: Q = αAθ. This study compares scaling exponents (θ) and coefficients (α) for floods of varying magnitude across a selection of major Atlantic Coast watersheds. Comparisons are made by normalizing flood discharges to a reference area bankfull discharge for each watershed. These watersheds capture the geologic and geomorphic transitions along the Atlantic Coast from narrow bedrock-dominated river valleys to wide coastal plain watersheds. Additionally, there is a range of hydrometeorological events that cause major floods in these basins including tropical storms, thunderstorm systems and winter-spring storms. The mix of flood-producing events changes along a gradient as well, with tropical storms and hurricanes increasing in dominance from north to south as a significant cause of major floods. Scaling exponents and coefficients were determined for both flood quantile estimates (e.g. 1.5-, 10-, 100-year floods) and selected hydrometeorological events (e.g. hurricanes, summer thunderstorms, winter-spring storms). Initial results indicate that southern coastal plain watersheds have lower scaling exponents (θ) than northern watersheds. However, the relative magnitudes of 100-year and other large floods are higher in the coastal plain rivers. In the transition zone between northern and southern watersheds, basins like the Potomac in the Mid-Atlantic region have similar scaling exponents as northern river basins, but relative flood magnitudes comparable to the southern coastal plain watersheds. These differences reflect variations in both geologic/geomorphic and climatic settings. Understanding these variations are important to appropriately using these relationships to improve flood risk models and analyses.
Scale effects on spatially varying relationships between urban landscape patterns and water quality.
Sun, Yanwei; Guo, Qinghai; Liu, Jian; Wang, Run
2014-08-01
Scientific interpretation of the relationships between urban landscape patterns and water quality is important for sustainable urban planning and watershed environmental protection. This study applied the ordinary least squares regression model and the geographically weighted regression model to examine the spatially varying relationships between 12 explanatory variables (including three topographical factors, four land use parameters, and five landscape metrics) and 15 water quality indicators in watersheds of Yundang Lake, Maluan Bay, and Xinglin Bay with varying levels of urbanization in Xiamen City, China. A local and global investigation was carried out at the watershed-level, with 50 and 200 m riparian buffer scales. This study found that topographical features and landscape metrics are the dominant factors of water quality, while land uses are too weak to be considered as a strong influential factor on water quality. Such statistical results may be related with the characteristics of land use compositions in our study area. Water quality variations in the 50 m buffer were dominated by topographical variables. The impact of landscape metrics on water quality gradually strengthen with expanding buffer zones. The strongest relationships are obtained in entire watersheds, rather than in 50 and 200 m buffer zones. Spatially varying relationships and effective buffer zones were verified in this study. Spatially varying relationships between explanatory variables and water quality parameters are more diversified and complex in less urbanized areas than in highly urbanized areas. This study hypothesizes that all these varying relationships may be attributed to the heterogeneity of landscape patterns in different urban regions. Adjustment of landscape patterns in an entire watershed should be the key measure to successfully improving urban lake water quality.
Scaling relations for watersheds
NASA Astrophysics Data System (ADS)
Fehr, E.; Kadau, D.; Araújo, N. A. M.; Andrade, J. S., Jr.; Herrmann, H. J.
2011-09-01
We study the morphology of watersheds in two and three dimensional systems subjected to different degrees of spatial correlations. The response of these objects to small, local perturbations is also investigated with extensive numerical simulations. We find the fractal dimension of the watersheds to generally decrease with the Hurst exponent, which quantifies the degree of spatial correlations. Moreover, in two dimensions, our results match the range of fractal dimensions 1.10≤df≤1.15 observed for natural landscapes. We report that the watershed is strongly affected by local perturbations. For perturbed two and three dimensional systems, we observe a power-law scaling behavior for the distribution of areas (volumes) enclosed by the original and the displaced watershed and for the distribution of distances between outlets. Finite-size effects are analyzed and the resulting scaling exponents are shown to depend significantly on the Hurst exponent. The intrinsic relation between watershed and invasion percolation, as well as relations between exponents conjectured in previous studies with two dimensional systems, are now confirmed by our results in three dimensions.
Development and implementation of a watershed management plan forLlac la Biche, Alberta, Canada.
White, J; Logan, M; Rawles, M
2006-01-01
Lakeland County is experiencing increasing developmental pressures arising from the oil and gas boom at nearby Fort McMurray. There is increased industrial traffic passing through the county, and 600 new residential lots are proposed in 2005, almost double from 5 years ago. Deteriorating surface water quality has been a concern in the area due to an increase in development and agriculture, while excessive fish harvesting and winterkills have impacted commercial and recreational fisheries. Today, walleye and pike populations in the lake remain collapsed and restocking efforts have not been successful. Due to the lack of studies done on the watershed, the county is leading a multidisciplinary research study which includes a baseline water quality study, riparian health assessments, land use mapping and ground-truthing and projects with the local health authority. This research has been summarized in a comprehensive state of the watershed report, which will be used to complete a watershed management plan for the Lac la Biche watershed. Recommendations from the state of the watershed report and watershed management plan will also be incorporated into municipal planning documents and recommend changes to the Municipal Government Act itself.
Climate, wildfire, and erosion ensemble foretells more sediment in western USA watersheds
Joel B. Sankey; Jason Kreitler; Todd J. Hawbaker; Jason L. McVay; Mary Ellen Miller; Erich R. Mueller; Nicole M. Vaillant; Scott E. Lowe; Temuulen T. Sankey
2017-01-01
The area burned annually by wildfires is expected to increase worldwide due to climate change. Burned areas increase soil erosion rates within watersheds, which can increase sedimentation in downstream rivers and reservoirs. However, which watersheds will be impacted by future wildfires is largely unknown. Using an ensemble of climate, fire, and erosion models, we show...
Spatiotemporal dynamics of landscape pattern and hydrologic process in watershed systems
NASA Astrophysics Data System (ADS)
Randhir, Timothy O.; Tsvetkova, Olga
2011-06-01
SummaryLand use change is influenced by spatial and temporal factors that interact with watershed resources. Modeling these changes is critical to evaluate emerging land use patterns and to predict variation in water quantity and quality. The objective of this study is to model the nature and emergence of spatial patterns in land use and water resource impacts using a spatially explicit and dynamic landscape simulation. Temporal changes are predicted using a probabilistic Markovian process and spatial interaction through cellular automation. The MCMC (Monte Carlo Markov Chain) analysis with cellular automation is linked to hydrologic equations to simulate landscape patterns and processes. The spatiotemporal watershed dynamics (SWD) model is applied to a subwatershed in the Blackstone River watershed of Massachusetts to predict potential land use changes and expected runoff and sediment loading. Changes in watershed land use and water resources are evaluated over 100 years at a yearly time step. Results show high potential for rapid urbanization that could result in lowering of groundwater recharge and increased storm water peaks. The watershed faces potential decreases in agricultural and forest area that affect open space and pervious cover of the watershed system. Water quality deteriorated due to increased runoff which can also impact stream morphology. While overland erosion decreased, instream erosion increased from increased runoff from urban areas. Use of urban best management practices (BMPs) in sensitive locations, preventive strategies, and long-term conservation planning will be useful in sustaining the watershed system.
NASA Astrophysics Data System (ADS)
Neary, D.; Ffolliott, P.; Stropki, C.
2009-04-01
The Rodeo-Chediski Wildfire - the largest in Arizona's history - damaged or destroyed ecosystem resources and disrupted ecosystem functioning in a largely mosaic pattern throughout the ponderosa pine (Pinus ponderosa) forests exposed to the burn. Impacts of this wildfire on tree overstories were studied on two watersheds in the area burned; one watershed burned by a high severity (stand-replacing) fire, while the other watershed burned by a low severity (stand-modifying) fire. The Rodeo-Chediski wildfire damaged or destroyed ecosystem resources and disrupted the ecological functioning on much of the 189,015 ha impacted by the burning. Intermingling chaparral shrub communities and pinyon-juniper woodlands at lower elevations and ponderosa pine forests at high elevations were located within the burned area. The wildfire was caused by two human ignitions that merged into one inferno. The Rodeo Fire was started by an arsonist on June 18, 2002, while the Chediski Fire was ignited as a signal fire by a stranded motorist on June 20th. The two fires merged on June 26, 2002, to become the Rodeo-Chediski Wildfire. The combined wildfires were contained on July 7th at a suppression (firefighting) cost of about €37.9 million (USA 50 million). However, the estimated costs associated with property losses; losses of ecosystem, anthropological, and cultural resources; and post-fire rehabilitation efforts increased the costs of the wildfire to over €114 million (USA 150 million). About one-half of the total area that was burned by the Rodeo-Chediski Wildfire experienced a high-severity fire, other areas burned at a low- to medium-severity fire, and still other areas were largely unburned according to a Burned Area Emergency Rehabilitation (BAER) report and fire severity map prepared shortly after containment of the wildfire. A mosaic of areas burned at varying fire severities within intermingling unburned areas resulted. Post-fire rehabilitation efforts, including establishment of water bars, wattles, k-rails, and aerial seeding and mulching of herbaceous plants to mitigate that anticipated accelerated post-fire soil erosion, began immediately after the fire was extinguished and it was declared safe for people to enter the burned area and initiate rehabilitation. An assessment of the impacts of the Rodeo-Chediski wildfire on soil erosion was carried out on two watersheds situated at the headwaters of the Little Colorado River. One of the watersheds experienced a high severity burn and the other a low-to-medium severity burn. Estimates of soil erosion on a watershed-basis and relative to physiographic characteristics on the two watersheds following the (a) high-intensity summer monsoonal rains and (2) low-intensity winter precipitation and spring snowmelt-runoff events are presented and compared with estimates of soil erosion following other wildfires in the region. Monitoring of soil erosion and other hydrologic and ecological parameters is continuing to obtain a longer, more comprehensive picture of the impacts of this catastrophic wildfire event. The Rodeo-Chediski Wildfire altered the species composition and impacted the production of herbaceous plants on the burned watersheds studied. Effects of the post-fire vegetation changes reduced the capabilities of watersheds to support livestock and some of the other larger herbivores in the region. When these watersheds will return to pre-fire conditions is largely unknown. Not only must the forage resources be restored but the magnitude of post-fire soil erosion and accompanying nutrient losses must be mitigated. Post-fire rehabilitation efforts including the seeding of herbaceous species and installation of controls to reduce soil erosion and sedimentation processes have helped to accelerate this recovery to some extent. A much longer time will obviously be required for severely burned areas to recover than those areas burned by at a low severity. Portions of the latter have already returned to pre-fire conditions.
Water resources of the Snake River watershed, east-central Minnesota
Lindholm, Gerald F.; Helgesen, J.O.; Broussard, W.L.; Ericson, D.W.
1974-01-01
The Snake River, which drains an area of about 1,030 square miles, originates in an extensive area of peat bogs in the northern part of the watershed. It flows southward across gently rolling glacial terrain in which the major relief is near the river. Near the southern boundary of the watershed, the Snake River turns eastward to its confluence with the St. Croix River. The northwest half of the watershed is heavily forested, whereas much of the southeast half has been cleared. The largest communities in the watershed, Mora and Pine City, had 1970 populations of 2,582 and 2,143, respectively.
NASA Astrophysics Data System (ADS)
Wei, C.; Cheng, K. S.
Using meteorological radar and satellite imagery had become an efficient tool for rainfall forecasting However few studies were aimed to predict quantitative rainfall in small watersheds for flood forecasting by using remote sensing data Due to the terrain shelter and ground clutter effect of Central Mountain Ridges the application of meteorological radar data was limited in mountainous areas of central Taiwan This study devises a new scheme to predict rainfall of a small upstream watershed by combing GOES-9 geostationary weather satellite imagery and ground rainfall records which can be applied for local quantitative rainfall forecasting during periods of typhoon and heavy rainfall Imagery of two typhoon events in 2004 and five correspondent ground raingauges records of Chitou Forest Recreational Area which is located in upstream region of Bei-Shi river were analyzed in this study The watershed accounts for 12 7 square kilometers and altitudes ranging from 1000 m to 1800 m Basin-wide Average Rainfall BAR in study area were estimated by block kriging Cloud Top Temperature CTT from satellite imagery and ground hourly rainfall records were medium correlated The regression coefficient ranges from 0 5 to 0 7 and the value decreases as the altitude of the gauge site increases The regression coefficient of CCT and next 2 to 6 hour accumulated BAR decrease as the time scale increases The rainfall forecasting for BAR were analyzed by Kalman Filtering Technique The correlation coefficient and average hourly deviates between estimated and observed value of BAR for
On the Complexity of Nutrient Transport in a Large Watershed in Ohio
NASA Astrophysics Data System (ADS)
Schwartz, F. W.; Allen, G.
2009-12-01
This paper examines key features of the hydrobiologic setting in controlling the cycling of nutrients through the major streams and rivers of a large agriculturally dominated watershed in central Ohio. The particular focus is on the roles of extreme rainfall events in generating nutrients, and role of reservoirs in attenuating nutrient concentrations. The study also highlights major gaps in process knowledge even in the face in the face of extensive regulatory and other monitoring. Although it has been recognized that reservoirs can significantly affect surface-water flows in watersheds, there is a growing recognition of the need for expanded and complementary studies to understand their role in nutrient transport. The study area is located in central Ohio and includes the entire Upper Scioto and the northern portion of the Lower Scioto River basins, an area encompassing approximately 9984 km2. Five of the sub-watersheds contain major surface-water storage reservoirs. Two watersheds are without reservoirs. There is intensive agriculture within the study area with corn and soybeans as the dominant crops. Tile drainage of fields provides an efficient and rapid connection of agricultural lands to surface waters, facilitating the loading of fertilizers and agrochemicals to surface streams. Storm flows in spring months that coincide with fertilizer applications often provide nitrate concentrations in excess of 10 mg/L as N. In spite of years of routine sampling for regulatory purposes, little is known about nutrient loading patterns during the few, brief, extreme events each year. Interpretations of a high resolution temporal chemical record of sampling on the Scioto River is frustrated by the complexity of loading and mixing as tributaries from sub-watersheds join the main stem of the Scioto River and nutrient utilization within the large reservoirs. Even with literally thousands of individual chemical measurements, extensive stream and precipitation data, the details of processes affecting nutrient transport remain uncertain.
Tovar, F.H.
1973-01-01
The U.S. Geological Survey, in cooperation with the Texas Water Development Board, began hydrologic studies in the Austin urban area in 1954. The objectives of this project are as follows: 1. To determine the effects of progressive urbanization on infiltration, rates of peak discharge, and rainfall-runoff relations in the Waller Creek watershed. 2. To provide rainfall-and-runoff data from the rural Wilbarger Creek watershed to be used for comparative purposes in determining the effects of existing and progressive urbanization in the Waller Creek watershed. 3. To provide applied research facilities for studies at the University of Texas at Austin. The purpose of this report is to present rainfall-and-runoff data for the Waller Creek and Wilbarger Creek study areas for the 1971 water year (October 1, 1970, to September 30, 1971). To facilitate the publication and distribution of this report at the earliest feasible time, certain material has been included that does not conform to the formal publication standards of the U.S. Geological Survey.
American River Watershed Investigation, California. Volume 6. Appendix S. Part 1
1991-12-01
Aimophila ruficeps C,R Chipping sparrow Spizella passerina C,R,W,F Major wildlife habitats of the American River Watershed Study Area include: riparian (R...Lazuli bunting Passerina amoena R,G,W,F Rufous-sided towhee Pipilo erythrophthalmus C,U,F Brown towhee Pipilo fuscus C,U,F Rufous-crowned sparrow ... system of canals, weirs, levees, pumping plants and other facilities to protect agricultural lands in the area by managing flood waters and
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bowen, Esther E.; Hamada, Yuki; O’Connor, Ben L.
Here, a recent assessment that quantified potential impacts of solar energy development on water resources in the southwestern United States necessitated the development of a methodology to identify locations of mountain front recharge (MFR) in order to guide land development decisions. A spatially explicit, slope-based algorithm was created to delineate MFR zones in 17 arid, mountainous watersheds using elevation and land cover data. Slopes were calculated from elevation data and grouped into 100 classes using iterative self-organizing classification. Candidate MFR zones were identified based on slope classes that were consistent with MFR. Land cover types that were inconsistent with groundwatermore » recharge were excluded from the candidate areas to determine the final MFR zones. No MFR reference maps exist for comparison with the study’s results, so the reliability of the resulting MFR zone maps was evaluated qualitatively using slope, surficial geology, soil, and land cover datasets. MFR zones ranged from 74 km2 to 1,547 km2 and accounted for 40% of the total watershed area studied. Slopes and surficial geologic materials that were present in the MFR zones were consistent with conditions at the mountain front, while soils and land cover that were present would generally promote groundwater recharge. Visual inspection of the MFR zone maps also confirmed the presence of well-recognized alluvial fan features in several study watersheds. While qualitative evaluation suggested that the algorithm reliably delineated MFR zones in most watersheds overall, the algorithm was better suited for application in watersheds that had characteristic Basin and Range topography and relatively flat basin floors than areas without these characteristics. Because the algorithm performed well to reliably delineate the spatial distribution of MFR, it would allow researchers to quantify aspects of the hydrologic processes associated with MFR and help local land resource managers to consider protection of critical groundwater recharge regions in their development decisions.« less
Bowen, Esther E.; Hamada, Yuki; O’Connor, Ben L.
2014-06-01
Here, a recent assessment that quantified potential impacts of solar energy development on water resources in the southwestern United States necessitated the development of a methodology to identify locations of mountain front recharge (MFR) in order to guide land development decisions. A spatially explicit, slope-based algorithm was created to delineate MFR zones in 17 arid, mountainous watersheds using elevation and land cover data. Slopes were calculated from elevation data and grouped into 100 classes using iterative self-organizing classification. Candidate MFR zones were identified based on slope classes that were consistent with MFR. Land cover types that were inconsistent with groundwatermore » recharge were excluded from the candidate areas to determine the final MFR zones. No MFR reference maps exist for comparison with the study’s results, so the reliability of the resulting MFR zone maps was evaluated qualitatively using slope, surficial geology, soil, and land cover datasets. MFR zones ranged from 74 km2 to 1,547 km2 and accounted for 40% of the total watershed area studied. Slopes and surficial geologic materials that were present in the MFR zones were consistent with conditions at the mountain front, while soils and land cover that were present would generally promote groundwater recharge. Visual inspection of the MFR zone maps also confirmed the presence of well-recognized alluvial fan features in several study watersheds. While qualitative evaluation suggested that the algorithm reliably delineated MFR zones in most watersheds overall, the algorithm was better suited for application in watersheds that had characteristic Basin and Range topography and relatively flat basin floors than areas without these characteristics. Because the algorithm performed well to reliably delineate the spatial distribution of MFR, it would allow researchers to quantify aspects of the hydrologic processes associated with MFR and help local land resource managers to consider protection of critical groundwater recharge regions in their development decisions.« less
NASA Astrophysics Data System (ADS)
Lim, T. C.
2016-12-01
Empirical evidence has shown linkages between urbanization, hydrological regime change, and degradation of water quality and aquatic habitat. Percent imperviousness, has long been suggested as the dominant source of these negative changes. However, recent research identifying alternative pathways of runoff production at the watershed scale have called into question percent impervious surface area's primacy in urban runoff production compared to other aspects of urbanization including change in vegetative cover, imported water and water leakages, and the presence of drainage infrastructure. In this research I show how a robust statistical methodology can detect evidence of variable source area (VSA)-type hydrologic response associated with incremental hydraulic connectivity in watersheds. I then use logistic regression to explore how evidence of VSA-type response relates to the physical and meterological characteristics of the watershed. I find that impervious surface area is highly correlated with development, but does not add significant explanatory power beyond percent developed in predicting VSA-type response. Other aspects of development morphology, including percent developed open space and type of drainage infrastructure also do not add to the explanatory power of undeveloped land in predicting VSA-type response. Within only developed areas, the effect of developed open space was found to be more similar to that of total impervious area than to undeveloped land. These findings were consistent when tested across a national cross-section of urbanized watersheds, a higher resolution dataset of Baltimore Metropolitan Area watersheds, and a subsample of watersheds confirmed not to be served by combined sewer systems. These findings suggest that land development policies that focus on lot coverage should be revisited, and more focus should be placed on preserving native vegetation and soil conditions alongside development.
NASA Astrophysics Data System (ADS)
Driscoll, J. M.
2015-12-01
Precipitation in the southwestern United States falls primarily in areas of higher elevation. Drought conditions over the past five years have limited snowpack and rainfall, increasing the vulnerability to and frequency of forest fires in these montane regions. In June 2012, the Little Bear fire burned approximately 69 square miles (44,200 acres) in high-elevation forests of the Rio Hondo headwater catchments, south-central New Mexico. Burn severity was high or moderate on 53 percent of the burn area. The Precipitation Runoff Modeling System (PRMS) is a publically-available watershed model developed by the U.S. Geological Survey (USGS). PRMS data are spatially distributed using a 'Geospatial Fabric' developed at a national scale to define Hydrologic Response Units (HRUs), based on topography and points of interest (such as confluences and streamgages). The Little Bear PRMS study area is comprised of 22 HRUs over a 587 square-mile area contributing to the Rio Hondo above Chavez Canyon streamgage (USGS ID 08390020), in operation from 2008 to 2014. Model input data include spatially-distributed climate data from the National Aeronautics and Space Administration (NASA) DayMet and land cover (such as vegetation and soil properties) data from the USGS Geo Data Portal. Remote sensing of vegetation over time has provided a spatial distribution of recovery and has been applied using dynamic parameters within PRMS on the daily timestep over the study area. Investigation into the source and timing of water budget components in the Rio Hondo watershed may assist water planners and managers in determining how the surface-water and groundwater systems will react to future land use/land cover changes. Further application of PRMS in additional areas will allow for comparison of streamflow before and following wildfire conditions, and may lead to better understanding of the changes in watershed-scale hydrologic processes in the Southwest through post-fire watershed recovery.
Assessment of sediment yield in a sloping Mediterranean watershed in Cyprus
NASA Astrophysics Data System (ADS)
Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado
2014-05-01
In the Mediterranean region, water catchment sediment yield as a result of erosion is higher than in many other regions in Europe due to the climatic conditions, topography, lithology and land-use. Modelling sediment transport is difficult due to intermittent stream flow and highly irregular rainfall conditions in this region. The objective of this study is to quantify sediment yield of a highly sloping Mediterranean environment. This study is conducted in the Peristerona Watershed in Cyprus, which has ephemeral water flow. In the downstream area a series of check dams have been placed across the stream to slow the flow and increase groundwater recharge. The surface area of the watershed, upstream of the check dams, is 103 km2 with elevation changing between 1540 m and 280 m and a mean local slope higher than 40% for the mountainous part and lower than 8% for the plain. The long-term average annual precipitation ranges from 755 mm in the upstream area to 276 mm in the plain. The surface extent of the sediment that was deposited at the most upstream check dam during two seasons was measured with a Differential Global Positioning System. The depth of the sediment was measured with utility poles and bulk density samples from the sediment profile were collected. The sediment had a surface area of 12600 m2 and an average depth of 0.23 m. The mean of the sediment dry bulk density samples was 1.05 t m-3 with a standard deviation of 0.11. Based on these values, area specific sediment yield was computed as 1 t ha-1 per year for the entire catchment area upstream of the check dam, assuming a check dam sediment trap efficiency of 15%. Erosion in the watershed is currently modeled with PESERA using detailed watershed data.
NASA Astrophysics Data System (ADS)
Vallianatos, Filippos; Kouli, Maria
2013-08-01
The Digital Elevation Model (DEM) for the Crete Island with a resolution of approximately 20 meters was used in order to delineate watersheds by computing the flow direction and using it in the Watershed function. The Watershed function uses a raster of flow direction to determine contributing area. The Geographic Information Systems routine procedure was applied and the watersheds as well as the streams network (using a threshold of 2000 cells, i.e. the minimum number of cells that constitute a stream) were extracted from the hydrologically corrected (free of sinks) DEM. A number of a few thousand watersheds were delineated, and their areal extent was calculated. From these watersheds a number of 300 was finally selected for further analysis as the watersheds of extremely small area were excluded in order to avoid possible artifacts. Our analysis approach is based on the basic principles of Complexity theory and Tsallis Entropy introduces in the frame of non-extensive statistical physics. This concept has been successfully used for the analysis of a variety of complex dynamic systems including natural hazards, where fractality and long-range interactions are important. The analysis indicates that the statistical distribution of watersheds can be successfully described with the theoretical estimations of non-extensive statistical physics implying the complexity that characterizes the occurrences of them.
NASA Astrophysics Data System (ADS)
Verma, S.; Bhattarai, R.; Cooke, R.
2011-12-01
The green house gas loading of the atmosphere has been increasing since the mid 19th century which threatens to dramatically change the earth's climate in the 21st Century. Scientific evidences show that earth's global average surface temperature has risen some 0.75°C (1.3°F) since 1850. Third Assessment Report (TAR) from the Intergovernmental Panel on Climate Change (IPCC) concluded that human activities have increased the atmospheric concentration of greenhouse gases (GHGs), which will result in a warming world and other changes in the climate. TAR has projected an increase in globally average surface temperature of 1.4 to 5.8 °C and an increase in precipitation of 5 to 20 % over the period of 1990 to 2100. Assuming a global temperature increase of between 2.8 and 5.2 °C, it was estimated a 7-15% increase in global evaporation and precipitation rates. Global warming and subsequent climate change could raise sea level by several tens of centimeters in the next fifty years. Such a rise may erode beaches, worsen coastal flooding and threaten water quality in estuaries and aquifers. With the climate already changing and further change in climate highly likely to happen, study of impact of climate and the adaptation is a necessary component of any response to climate change. The objective of this study is to analyze the impact of climate change on runoff and sediment delivery in a Great Lake watershed located in Northern Ohio. Maumee River watershed is predominantly an agricultural watershed with an area of 6330 sq mile and drains to Lake Erie. Agricultural area covers about 89.9% of the watershed while wooded area covers 7.3%, 1.2% is urban area and other land uses account for 1.6%. Water Quality Laboratory, Heidelberg College has monitored the watershed for last 25 years. The Soil and Water Assessment Tool (SWAT) model is used for both water quantity and water quality simulations for past and future scenarios. SWAT is a continuous, long-term watershed scale simulation model which operates on a daily time step. The model is physically based, computationally efficient, and capable of assessing the impact of climate and watershed management on water, sediment, and nutrient/chemical yields. SWAT model has been calibrated for flow and sediment yield from 1982 to 2002 for the watershed. The calibrated model will be used to predict future flow and sediment delivery scenarios due to climate change (increase in temperature).
Placing the pieces: Reconstructing the original property mosaic in a warrant and patent watershed
Bain, D.J.; Brush, G.S.
2005-01-01
Recent research shows that land use history is an important determinant of current ecosystem function. In the United States, characterization of land use change following European settlement requires reconstruction of the original property mosaic. However, this task is difficult in unsystematically surveyed areas east of the Appalachian Mountains. The Gwynns Falls watershed (Baltimore, MD) was originally surveyed in the 1600-1700s under a system of warrants and patents (commonly known as 'metes and bounds'). A method for the reconstruction and mapping of warrant and patent properties is presented and used to map the original property mosaic in the Gwynns Falls watershed. Using the mapped mosaic, the persistence of properties and property lines in the current Gwynns Falls landscape is considered. The results of this research indicate that as in agricultural areas, the original property lines in the Gwynns Falls watershed are persistent. At the same time, the results suggest that the property mosaic in heavily urbanized/suburbanized areas is generally 'reset.' Further, trends in surveying technique, parcel size, and settlement patterns cause property line density and property shape complexity to increase in the less urbanized upper watershed. The persistence of original patterns may be damping expression of heterogeneity gradients in this urban landscape. This spatial pattern of complexity in the original mosaic is directly opposite of hypothesized patterns of landscape heterogeneity arising from urbanization. The technique reported here and the resulting observations are important for landscape pattern studies in areas settled under unsystematic survey systems, especially the heavily urbanized areas of the eastern United States. ?? 2004 Kluwer Academic Publishers.
Climate, wildfire, and erosion ensemble foretells more sediment in western USA watersheds
Sankey, Joel B.; Kreitler, Jason R.; Hawbaker, Todd; McVay, Jason L.; Miller, Mary Ellen; Mueller, Erich R.; Vaillant, Nicole M.; Lowe, Scott E.; Sankey, Temuulen T.
2017-01-01
The area burned annually by wildfires is expected to increase worldwide due to climate change. Burned areas increase soil erosion rates within watersheds, which can increase sedimentation in downstream rivers and reservoirs. However, which watersheds will be impacted by future wildfires is largely unknown. Using an ensemble of climate, fire, and erosion models, we show that post-fire sedimentation is projected to increase for nearly nine-tenths of watersheds by > 10% and for more than one-third of watersheds by > 100% by the 2041 to 2050 decade in the western USA. The projected increases are statistically significant for more than eight-tenths of the watersheds. In the western USA, many human communities rely on water from rivers and reservoirs that originates in watersheds where sedimentation is projected to increase. Increased sedimentation could negatively impact water supply and quality for some communities, in addition to affecting stream channel stability and aquatic ecosystems.
NASA Technical Reports Server (NTRS)
Jenkins, D. W.
1972-01-01
NASA chose the watershed of Rhode River, a small sub-estuary of the Bay, as a representative test area for intensive studies of remote sensing, the results of which could be extrapolated to other estuarine watersheds around the Bay. A broad program of ecological research was already underway within the watershed, conducted by the Smithsonian Institution's Chesapeake Bay Center for Environmental Studies (CBCES) and cooperating universities. This research program offered a unique opportunity to explore potential applications for remote sensing techniques. This led to a joint NASA-CBCES project with two basic objectives: to evaluate remote sensing data for the interpretation of ecological parameters, and to provide essential data for ongoing research at the CBCES. A third objective, dependent upon realization of the first two, was to extrapolate photointerpretive expertise gained at the Rhode River watershed to other portions of the Chesapeake Bay.
Garcia, Ana Maria
2009-01-01
A study of the Currituck Sound was initiated in 2005 to evaluate the water chemistry of the Sound and assess the effectiveness of management strategies. As part of this study, the Soil and Water Assessment Tool (SWAT) model was used to simulate current sediment and nutrient loadings for two distinct watersheds in the Currituck Sound basin and to determine the consequences of different water-quality management scenarios. The watersheds studied were (1) Tull Creek watershed, which has extensive row-crop cultivation and artificial drainage, and (2) West Neck Creek watershed, which drains urban areas in and around Virginia Beach, Virginia. The model simulated monthly streamflows with Nash-Sutcliffe model efficiency coefficients of 0.83 and 0.76 for Tull Creek and West Neck Creek, respectively. The daily sediment concentration coefficient of determination was 0.19 for Tull Creek and 0.36 for West Neck Creek. The coefficient of determination for total nitrogen was 0.26 for both watersheds and for dissolved phosphorus was 0.4 for Tull Creek and 0.03 for West Neck Creek. The model was used to estimate current (2006-2007) sediment and nutrient yields for the two watersheds. Total suspended-solids yield was 56 percent lower in the urban watershed than in the agricultural watershed. Total nitrogen export was 45 percent lower, and total phosphorus was 43 percent lower in the urban watershed than in the agricultural watershed. A management scenario with filter strips bordering the main channels was simulated for Tull Creek. The Soil and Water Assessment Tool model estimated a total suspended-solids yield reduction of 54 percent and total nitrogen and total phosphorus reductions of 21 percent and 29 percent, respectively, for the Tull Creek watershed.
Melching, C.S.; Marquardt, J.S.
1997-01-01
Design hydrographs computed from design storms, simple models of abstractions (interception, depression storage, and infiltration), and synthetic unit hydrographs provide vital information for stormwater, flood-plain, and water-resources management throughout the United States. Rainfall and runoff data for small watersheds in Lake County collected between 1990 and 1995 were studied to develop equations for estimation of synthetic unit-hydrograph parameters on the basis of watershed and storm characteristics. The synthetic unit-hydrograph parameters of interest were the time of concentration (TC) and watershed-storage coefficient (R) for the Clark unit-hydrograph method, the unit-graph lag (UL) for the Soil Conservation Service (now known as the Natural Resources Conservation Service) dimensionless unit hydrograph, and the hydrograph-time lag (TL) for the linear-reservoir method for unit-hydrograph estimation. Data from 66 storms with effective-precipitation depths greater than 0.4 inches on 9 small watersheds (areas between 0.06 and 37 square miles (mi2)) were utilized to develop the estimation equations, and data from 11 storms on 8 of these watersheds were utilized to verify (test) the estimation equations. The synthetic unit-hydrograph parameters were determined by calibration using the U.S. Army Corps of Engineers Flood Hydrograph Package HEC-1 (TC, R, and UL) or by manual analysis of the rainfall and run-off data (TL). The relation between synthetic unit-hydrograph parameters, and watershed and storm characteristics was determined by multiple linear regression of the logarithms of the parameters and characteristics. Separate sets of equations were developed with watershed area and main channel length as the starting parameters. Percentage of impervious cover, main channel slope, and depth of effective precipitation also were identified as important characteristics for estimation of synthetic unit-hydrograph parameters. The estimation equations utilizing area had multiple correlation coefficients of 0.873, 0.961, 0.968, and 0.963 for TC, R, UL, and TL, respectively, and the estimation equations utilizing main channel length had multiple correlation coefficients of 0.845, 0.957, 0.961, and 0.963 for TC, R, UL, and TL, respectively. Simulation of the measured hydrographs for the verification storms utilizing TC and R obtained from the estimation equations yielded good results without calibration. The peak discharge for 8 of the 11 storms was estimated within 25 percent and the time-to-peak discharge for 10 of the 11 storms was estimated within 20 percent. Thus, application of the estimation equations to determine synthetic unit-hydrograph parameters for design-storm simulation may result in reliable design hydrographs; as long as the physical characteristics of the watersheds under consideration are within the range of those for the watersheds in this study (area: 0.06-37 mi2, main channel length: 0.33-16.6 miles, main channel slope: 3.13-55.3 feet per mile, and percentage of impervious cover: 7.32-40.6 percent). The estimation equations are most reliable when applied to watersheds with areas less than 25 mi2.
Sustained winter streamflow from groundmelt
C. Anthony Federer
1965-01-01
The watersheds of the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire are among the few small gaged watersheds for which continuous winter streamflow records are obtained while deep snow covers the area. Records show that a remarkably steady flow of between 0.006 and 0.025 area-inch of water per day leaves the watershed in spite of snow depths...
Diverse multi-decadal changes in streamflow within a rapidly urbanizing region
NASA Astrophysics Data System (ADS)
Diem, Jeremy E.; Hill, T. Chee; Milligan, Richard A.
2018-01-01
The impact of urbanization on streamflow depends on a variety of factors (e.g., climate, initial land cover, inter-basin transfers, water withdrawals, wastewater effluent, etc.). The purpose of this study is to examine trends in streamflow from 1986 to 2015 in a range of watersheds within the rapidly urbanizing Atlanta, GA metropolitan area. This study compares eight watersheds over three decades, while minimizing the influence of inter-annual precipitation variability. Population and land-cover data were used to analyze changes over approximately twenty years within the watersheds. Precipitation totals for the watersheds were estimated using precipitation totals at nearby weather stations. Multiple streamflow variables, such as annual streamflow, frequencies of high-flow days (HFDs), flashiness, and precipitation-adjusted streamflow, for the eight streams were calculated using daily streamflow data. Variables were tested for significant trends from 1986 to 2015 and significant differences between 1986-2000 and 2001-2015. Flashiness increased for all streams without municipal water withdrawals, and the four watersheds with the largest increase in developed land had significant increases in flashiness. Significant positive trends in precipitation-adjusted mean annual streamflow and HFDs occurred for the two watersheds (Big Creek and Suwanee Creek) that experienced the largest increases in development, and these were the only watersheds that went from majority forest land in 1986 to majority developed land in 2015. With a disproportionate increase in HFD occurrence during summer, Big Creek and Suwannee Creek also had a reduction in intra-annual variability of HFD occurrence. Watersheds that were already substantially developed at the beginning of the period and did not have wastewater discharge had declining streamflow. The most urbanized watershed (Peachtree Creek) had a significant decrease in streamflow, and a possible cause of the decrease was increasing groundwater infiltration into sewers. The impacts of urbanization on streamflow within the metropolitan area have undoubtedly been felt by a wide of range of communities.
NASA Astrophysics Data System (ADS)
Maghrebi, M.; Tajrishy, M.
2010-12-01
Jajrood River watershed is one of the main drinking water resources of the capital city of Tehran, Iran. In addition it has been available as many recreational usages especially in the warm months. As a result of being located near one of the crowded cities of the world, a variety of microbial pollutions is commonly perceived in the Jajrood River. Among them, there are strong concerns about fecal coliform bacteria concentration. This article aimed to model fate and transport of fecal coliform bacteria in Jajrood River watershed using Soil and Water Assessment Tool (SWAT) model version 2005. Potential pollutant sources in the study area were detected and quantified for modeling purposes. In spite of being lack of knowledge about bacteria die-off rate in small river bodies, as well as in other watershed-based forms, fecal coliform bacteria die-off rates were estimated using both laboratory and field data investigations with some simplifications. The SWAT model was calibrated over an extended time period (1997-2002) for this watershed. The river flow calibrated using SUFI-2 software and resulted in a very good outputs (R2=0.82, E=0.81). Furthermore SWAT model was validated over January 2003 to September 2005 in the study area and has resulted in good outputs (R2=0.61, E=0.57). This research illustrates SWAT 2005 capability to model fecal coliform bacteria in a populated watershed, and deals with most of watershed microbial pollution sources that are usually observed in developing countries. Fecal coliform concentration simulation results were mostly in the same order in comparison with real data. However, Differences were judged to be related to lack of input data. In this article different aspects of SWAT capabilities for modeling of fecal coliform bacteria concentration will be reviewed and it will present new insights in bacteria modeling procedures especially for mountainous, high populated and small sized watersheds.
NASA Astrophysics Data System (ADS)
Kume, T.; Tsuruta, K.; Komatsu, H.; Shinohara, Y.; Otsuki, K.
2011-12-01
Several different methods to assess water use are available, and the sap flux measurement technique is one of the most promising methods, especially in monotonous watershed. Previously, three spatial levels of scaling have been used to obtain bottom-up transpiration estimates based on the sap flux technique: from within-tree to tree, from tree to stand, and from stand to watershed or landscape. Although there are considerable variations that must be taken into account at each step, few studies have examined plot-to-plot variability of stand-scale transpirations. To design optimum sampling method to accurately estimate transpiration at the watershed-scale, it is indispensable to understand heterogeneity of stand-scale transpiration in a forested watershed and the factors determining the heterogeneity. This study was undertaken to clarify differences of stand-scale transpirations within a watershed and the factors determining the differences. To this aim, we conducted sap flux-based transpiration estimates in two plots such as a lower riparian (RZ) and an upper ridge (UZ) zone in a watershed with Japanese cypress plantation, Kyushu, Japan in two years. Tree height and diameter of breast height (DBH) were lager in RZ than those of UZ. The stand sapwood area (As) was lager in RZ than UZ (21.9 cm2h a-1, 16.8 cm2ha-1, respectively). Stand mean sap flux (Js) in RZ was almost same as that of UZ when relatively lower Js, while, Js in RZ was higher than that of UZ when relatively higher Js (i.e., bright days in summer season). Consequently, daily stand-scale transpiration (E), which is the multiple of As and Js, differed by two times between RZ and UZ in summer season. This study found significant heterogeneity of stand-scale transpiration within the watershed and that the differences could be caused by two aspects such as stand structure and sap flux velocity.
7 CFR 1781.3 - Authorities, responsibilities, and delegation of authority.
Code of Federal Regulations, 2011 CFR
2011-01-01
... AND WATERSHED (WS) LOANS AND ADVANCES § 1781.3 Authorities, responsibilities, and delegation of... developing WS and RCD area plans and for individual RCD measures or projects and watershed works of improvement. The watershed work plan for developing, operating, and maintaining watershed works of improvement...
7 CFR 1781.3 - Authorities, responsibilities, and delegation of authority.
Code of Federal Regulations, 2013 CFR
2013-01-01
... AND WATERSHED (WS) LOANS AND ADVANCES § 1781.3 Authorities, responsibilities, and delegation of... developing WS and RCD area plans and for individual RCD measures or projects and watershed works of improvement. The watershed work plan for developing, operating, and maintaining watershed works of improvement...
7 CFR 1781.3 - Authorities, responsibilities, and delegation of authority.
Code of Federal Regulations, 2012 CFR
2012-01-01
... AND WATERSHED (WS) LOANS AND ADVANCES § 1781.3 Authorities, responsibilities, and delegation of... developing WS and RCD area plans and for individual RCD measures or projects and watershed works of improvement. The watershed work plan for developing, operating, and maintaining watershed works of improvement...
7 CFR 1781.3 - Authorities, responsibilities, and delegation of authority.
Code of Federal Regulations, 2014 CFR
2014-01-01
... AND WATERSHED (WS) LOANS AND ADVANCES § 1781.3 Authorities, responsibilities, and delegation of... developing WS and RCD area plans and for individual RCD measures or projects and watershed works of improvement. The watershed work plan for developing, operating, and maintaining watershed works of improvement...
Ramireddygari, S.R.; Sophocleous, M.A.; Koelliker, J.K.; Perkins, S.P.; Govindaraju, R.S.
2000-01-01
This paper presents the results of a comprehensive modeling study of surface and groundwater systems, including stream-aquifer interactions, for the Wet Walnut Creek Watershed in west-central Kansas. The main objective of this study was to assess the impacts of watershed structures and irrigation water use on streamflow and groundwater levels, which in turn affect availability of water for the Cheyenne Bottoms Wildlife Refuge Management area. The surface-water flow model, POTYLDR, and the groundwater flow model, MODFLOW, were combined into an integrated, watershed-scale, continuous simulation model. Major revisions and enhancements were made to the POTYLDR and MODFLOW models for simulating the detailed hydrologic budget for the Wet Walnut Creek Watershed. The computer simulation model was calibrated and verified using historical streamflow records (at Albert and Nekoma gaging stations), reported irrigation water use, observed water-level elevations in watershed structure pools, and groundwater levels in the alluvial aquifer system. To assess the impact of watershed structures and irrigation water use on streamflow and groundwater levels, a number of hypothetical management scenarios were simulated under various operational criteria for watershed structures and different annual limits on water use for irrigation. A standard 'base case' was defined to allow comparative analysis of the results of different scenarios. The simulated streamflows showed that watershed structures decrease both streamflows and groundwater levels in the watershed. The amount of water used for irrigation has a substantial effect on the total simulated streamflow and groundwater levels, indicating that irrigation is a major budget item for managing water resources in the watershed. (C) 2000 Elsevier Science B.V.This paper presents the results of a comprehensive modeling study of surface and groundwater systems, including stream-aquifer interactions, for the Wet Walnut Creek Watershed in west-central Kansas. The main objective of this study was to assess the impacts of watershed structures and irrigation water use on streamflow and groundwater levels, which in turn affect availability of water for the Cheyenne Bottoms Wildlife Refuge Management area. The surface-water flow model, POTYLDR, and the groundwater flow model, MODFLOW, were combined into an integrated, watershed-scale, continuous simulation model. Major revisions and enhancements were made to the POTYLDR and MODFLOW models for simulating the detailed hydrologic budget for the Wet Walnut Creek Watershed. The computer simulation model was calibrated and verified using historical streamflow records (at Albert and Nekoma gaging stations), reported irrigation water use, observed water-level elevations in watershed structure pools, and groundwater levels in the alluvial aquifer system. To assess the impact of watershed structures and irrigation water use on streamflow and groundwater levels, a number of hypothetical management scenarios were simulated under various operational criteria for watershed structures and different annual limits on water use for irrigation. A standard `base case' was defined to allow comparative analysis of the results of different scenarios. The simulated streamflows showed that watershed structures decrease both streamflows and groundwater levels in the watershed. The amount of water used for irrigation has a substantial effect on the total simulated streamflow and groundwater levels, indicating that irrigation is a major budget item for managing water resources in the watershed.A comprehensive simulation model that combines the surface water flow model POTYLDR and the groundwater flow model MODFLOW was used to study the impacts of watershed structures (e.g., dams) and irrigation water use (including stream-aquifer interactions) on streamflow and groundwater. The model was revised, enhanced, calibrated, and verified, then applied to evaluate the hydrologic budget for Wet Wal
Riparian erosion vulnerability model based on environmental features.
Botero-Acosta, Alejandra; Chu, Maria L; Guzman, Jorge A; Starks, Patrick J; Moriasi, Daniel N
2017-12-01
Riparian erosion is one of the major causes of sediment and contaminant load to streams, degradation of riparian wildlife habitats, and land loss hazards. Land and soil management practices are implemented as conservation and restoration measures to mitigate the environmental problems brought about by riparian erosion. This, however, requires the identification of vulnerable areas to soil erosion. Because of the complex interactions between the different mechanisms that govern soil erosion and the inherent uncertainties involved in quantifying these processes, assessing erosion vulnerability at the watershed scale is challenging. The main objective of this study was to develop a methodology to identify areas along the riparian zone that are susceptible to erosion. The methodology was developed by integrating the physically-based watershed model MIKE-SHE, to simulate water movement, and a habitat suitability model, MaxEnt, to quantify the probability of presences of elevation changes (i.e., erosion) across the watershed. The presences of elevation changes were estimated based on two LiDAR-based elevation datasets taken in 2009 and 2012. The changes in elevation were grouped into four categories: low (0.5 - 0.7 m), medium (0.7 - 1.0 m), high (1.0 - 1.7 m) and very high (1.7 - 5.9 m), considering each category as a studied "species". The categories' locations were then used as "species location" map in MaxEnt. The environmental features used as constraints to the presence of erosion were land cover, soil, stream power index, overland flow, lateral inflow, and discharge. The modeling framework was evaluated in the Fort Cobb Reservoir Experimental watershed in southcentral Oklahoma. Results showed that the most vulnerable areas for erosion were located at the upper riparian zones of the Cobb and Lake sub-watersheds. The main waterways of these sub-watersheds were also found to be prone to streambank erosion. Approximatively 80% of the riparian zone (streambank included) has up to 30% probability to experience erosion greater than 1.0 m. By being able to identify the most vulnerable areas for stream and riparian sediment mobilization, conservation and management practices can be focused on areas needing the most attention and resources. Copyright © 2017 Elsevier Ltd. All rights reserved.
Carl N. Skinner
1995-01-01
Change in the spatial characteristics of forest openings was investigated in three forested watersheds in northwestern Siskiyou County, California totalling approximately 24,600 hectares. Watersheds with minimal human disturbance were chosen for study. However, fi;e suppression has been pervasive throughout. Characteristics of forest openings (area, perimeter, distance...
Trends in water yield under climate change and urbanization in the U.S. mid-atlantic region
USDA-ARS?s Scientific Manuscript database
Changes in climate and land use are two primary drivers of hydrologic adjustment. This study analyzes forty years of water resources data for ten watersheds in the Washington, DC, metropolitan area to quantify the impact of climate change and urbanization on water yield. The watersheds investigated ...
Spatial Translation and Scaling Up of LID Practices in Deer Creek Watershed in East Missouri
NASA Astrophysics Data System (ADS)
Di Vittorio, Damien
This study investigated two important aspects of hydrologic effects of low impact development (LID) practices at the watershed scale by (1) examining the potential benefits of scaling up of LID design, and (2) evaluating downstream effects of LID design and its spatial translation within a watershed. The Personal Computer Storm Water Management Model (PCSWMM) was used to model runoff reduction with the implementation of LID practices in Deer Creek watershed (DCW), Missouri. The model was calibrated from 2003 to 2007 (R2 = 0.58 and NSE = 0.57), and validated from 2008 to 2012 (R2 = 0.64 and NSE = 0.65) for daily direct runoff. Runoff simulated for the study period, 2003 to 2012 (NSE = 0.61; R2 = 0.63), was used as the baseline for comparison to LID scenarios. Using 1958 areal imagery to assign land cover, a predevelopment scenario was constructed and simulated to assess LID scenarios' ability to restore predevelopment hydrologic conditions. The baseline and all LID scenarios were simulated using 2006 National Land Cover Dataset. The watershed was divided in 117 subcatchments, which were clustered in six groups of approximately equal areas and two scaling concepts consisting of incremental scaling and spatial scaling were modelled. Incremental scaling was investigated using three LID practices (rain barrel, porous pavement, and rain garden). Each LID practice was simulated at four implementation levels (25%, 50%, 75%, and 100%) in all subcatchments for the study period (2003 to 2012). Results showed an increased runoff reduction, ranging from 3% to 31%, with increased implementation level. Spatial scaling was investigated by increasing the spatial extent of LID practices using the subcatchment groups and all three LID practices (combined) implemented at 50% level. Results indicated that as the spatial extent of LID practices increased the runoff reduction at the outlet also increased, ranging from 3% to 19%. Spatial variability of LID implementation was examined by normalizing LID treated area to impervious area for each subcatchment group. The normalized LID implementation levels for each group revealed a reduction in runoff at the outlet of the watershed, ranging from 0.6% to 3.7%. This study showed that over a long-term period LID practices could restore pre-development hydrologic conditions. The optimal location for LID practice implementation within the study area was found to be near the outlet; however, these results cannot be generalized for all watersheds.
How Misapplication of the Hydrologic Unit Framework ...
Hydrologic units provide a convenient nationwide set of geographic polygons based on an arbitrary subdivision of the drainage of land surface areas at several hierarchical levels. Half or more of these units, however, are not true watersheds as the official name of the framework, Watershed Boundary Dataset (WBD), implies. Hydrologic units and watersheds are commonly treated as synonymous, and this misuse and misunderstanding can have some serious consequences. We discuss some of the strengths and limitations of watersheds and hydrologic units as spatial frameworks. Using examples from the Northwest and Southeast U.S., we explain how the misuse of the hydrologic unit framework has affected the meaning of watersheds and can impair the understanding of the associations of spatial geographic phenomena relative to a potentially infinite number of points on streams due to their linear nature. Watersheds are a fundamental geographic unit used to study the effects of natural and anthropogenic characteristics on the quality and quantity of water. Most scientists and resource managers historically have been in agreement on the spatial meaning of the term ‘watershed’ – that is, the topographic area within which water drains to a specific point on a stream, river, or particular waterbody. The Hydrologic Unit Code (HUC) framework, however, has changed this understanding. Hydrologic units provide a convenient nationwide set of geographic polygons based on an arbitra
Simultaneous Semi-Distributed Model Calibration Guided by ...
Modelling approaches to transfer hydrologically-relevant information from locations with streamflow measurements to locations without such measurements continues to be an active field of research for hydrologists. The Pacific Northwest Hydrologic Landscapes (PNW HL) provide a solid conceptual classification framework based on our understanding of dominant processes. A Hydrologic Landscape code (5 letter descriptor based on physical and climatic properties) describes each assessment unit area, and these units average area 60km2. The core function of these HL codes is to relate and transfer hydrologically meaningful information between watersheds without the need for streamflow time series. We present a novel approach based on the HL framework to answer the question “How can we calibrate models across separate watersheds simultaneously, guided by our understanding of dominant processes?“. We should be able to apply the same parameterizations to assessment units of common HL codes if 1) the Hydrologic Landscapes contain hydrologic information transferable between watersheds at a sub-watershed-scale and 2) we use a conceptual hydrologic model and parameters that reflect the hydrologic behavior of a watershed. In this study, This work specifically tests the ability or inability to use HL-codes to inform and share model parameters across watersheds in the Pacific Northwest. EPA’s Western Ecology Division has published and is refining a framework for defining la
Water resources of the Minnesota River-Hawk Creek watershed, southwestern Minnesota
Van Voast, Wayne A.; Broussard, W.L.; Wheat, D.E.
1972-01-01
The Minnesota River – Hawk Creek watershed is located in southwestern Minnesota. The watershed has an area of 1,479 square miles and is drained along its southwestern edge by the Minnesota River (Minnesota Division of Waters, 1959). The major watercourse within the watershed is Hawk Creek, having a drainage area of 510 square miles. Other, shorter streams drain into the Minnesota River but are mostly ephemeral. The watershed has a gently undulating land surface formed on glacial deposits. Directly underlying the glacial deposits in most of the area are Cretaceous sedimentary rocks. Paleozoic and Precambrian rocks are also locally in contact with overlying glacial deposits. Beds of sand and gravel buried at various depths within the glacial deposits are generally thin and discomtinuous but are the most accessible and widely used aquifers in the watershed. Beds of poorly consolidated sandstone in the Cretaceous rocks are locally good aquifers, generally yielding softer water, but in lesser quantities, than aquifers in the overlying glacial deposits. In the eastern part of the watershed, aquifers in Paleozoic and Precambrian sedimentary rocks are capable of high yields to wells and contain water of similar quality to water in the overlying Cretaceous and glacial deposits.
Linking Watershed Nitrogen Sources with Nitrogen Dynamics in Rivers of Western Oregon, USA
NASA Astrophysics Data System (ADS)
Sobota, D. J.; Compton, J.; Goodwin, K. E.
2012-12-01
We constructed contemporary nitrogen (N) budgets for 25 river basins in the Willamette River Basin (WRB) of western Oregon, USA, to improve the understanding of how recent trends in human-driven N loading have influenced riverine N dynamics in the region. Nearly 20% of WRB stream length is currently in fair or poor condition because of high N concentrations. Additionally, nitrate contamination of drinking water affects at least 8,000 people in the WRB. We hypothesized that 1) the majority of N inputs in the WRB would originate from agricultural activities in lowland portions of watersheds, 2) annual riverine N yield (kg/ha/yr) would correspond to annual per area watershed N inputs, and 3) riverine N yields would be seasonal and highest during winter due to the region's Mediterranean climate. We calculated average annual N inputs for each study basin by summing newly available datasets describing spatially explicit N inputs of synthetic fertilizer, atmospheric deposition, crop biological N2 fixation, biological N2 fixation by red alder (Alnus rubra Bong.), livestock manure, and point sources for the period 1996 - 2007. Annual and seasonal riverine N exports were estimated with the USGS model LOADEST calibrated to N concentration data collected during the study period. We estimated that two-thirds of total N input to the WRB study basins in the 2000s came from synthetic fertilizer application. Nearly all fertilizer application occurred on the lowlands near watershed mouths. We found a wide range of riverine N yields from the study basins, ranging from one to 70 kg N/ha/yr. Across the study basins, N export was more strongly correlated to fertilizer application rates than to percent of agricultural area in the watershed. Low watershed N yields reflected a high proportion of watershed area in the forested Cascade Mountain Range, which received low N inputs mainly from atmospheric deposition. N yields from study basins were strongly seasonal, with at least 50%, and often 75%, of annual N yield occurring in fall and winter months. Our results suggest that that spatially explicit data on specific crop types and crop practices are valuable for explaining spatial and temporal variation of nutrient concentrations in WRB rivers. This emphasizes the need for careful tracking of non-point N inputs to inform water quality monitoring and management.
NASA Astrophysics Data System (ADS)
Evrard, O.; Navratil, O.; Gratiot, N.; Némery, J.; Duvert, C.; Ayrault, S.; Lefèvre, I.; Legout, C.; Bonté, P.; Esteves, M.
2009-12-01
In mountainous environments, an excessive fine sediment supply to the rivers typically leads to an increase in water turbidity, contaminant transport and a rapid filling of reservoirs. This situation is particularly problematic in regions where water reservoirs are used to provide drinking water to large cities (e.g. in central Mexico) or where stream water is used to run hydroelectric power plants (e.g. in the French Southern Alps). In such areas, sediment source areas first need to be delineated and sediment fluxes between hillslopes and the river system must be better understood before implementing efficient erosion control measures. In this context, the STREAMS (« Sediment Transport and Erosion Across MountainS ») project funded by the French National Research Agency (ANR) aims at understanding the spatial and temporal dynamics of sediment at the scale of mountainous watersheds (between 500 - 1000 km2) located in contrasted environments. This 3-years study is carried out simultaneously in a volcanic watershed located in the Mexican transvolcanic belt undergoing a subhumid tropical climate, as well as in a sedimentary watershed of the French Southern Alps undergoing a transitional climate with Mediterranean and continental influences. One of the main specificities of this project consists in combining traditional monitoring techniques (i.e. installation of river gauges, turbidimeters and sediment samplers in several sub-catchments) and sediment fingerprinting using elemental geochemistry (measured by Instrumental Neutron Activation Analysis - INAA - and Inductively Coupled Plasma - Mass Spectrometry - ICP-MS) and fallout radionuclides (measured by gamma spectrometry). In the French watershed, geochemical analysis allows outlining different sediment sources (e.g. the contribution of calcareous vs. marl-covered sub-watersheds). Radionuclide ratios (e.g.Be-7/Cs-137) allow identifying the dominant erosion processes occurring within the watershed. Areas mostly affected by gully erosion, rill or sheet erosion have been delineated. Furthermore, the measurement of radionuclide content in suspended sediment after the snowmelt suggests that most of this sediment consists in resuspended material rather than on newly eroded soil. In the Mexican watershed, a different contribution of andisols and acrisols to erosion is suspected. Overall, the bulk of erosion is generated by rather small areas within the watershed. In this region characterised by a succession of wet and dry seasons, the Be-7 content in rainfall and sediment has been measured at the scale of a 2.5 km2 sub-watershed in order to better understand the erosion transfer between hillslopes and rivers during the rainy season. This outlines the contribution of individual storms to seasonal erosion. Overall, this study brings important insights about sediment sources and fluxes within these watersheds located in contrasted environments. A further step consists in comparing experimental results with model outputs, and to evaluate the impact of on-going erosion mitigation measures.
The Great Lakes Hydrography Dataset: Consistent, binational ...
Ecosystem-based management of the Laurentian Great Lakes, which spans both the United States and Canada, is hampered by the lack of consistent binational watersheds for the entire Basin. Using comparable data sources and consistent methods we developed spatially equivalent watershed boundaries for the binational extent of the Basin to create the Great Lakes Hydrography Dataset (GLHD). The GLHD consists of 5,589 watersheds for the entire Basin, covering a total area of approximately 547,967 km2, or about twice the 247,003 km2 surface water area of the Great Lakes. The GLHD improves upon existing watershed efforts by delineating watersheds for the entire Basin using consistent methods; enhancing the precision of watershed delineation by using recently developed flow direction grids that have been hydrologically enforced and vetted by provincial and federal water resource agencies; and increasing the accuracy of watershed boundaries by enforcing embayments, delineating watersheds on islands, and delineating watersheds for all tributaries draining to connecting channels. In addition, the GLHD is packaged in a publically available geodatabase that includes synthetic stream networks, reach catchments, watershed boundaries, a broad set of attribute data for each tributary, and metadata documenting methodology. The GLHD provides a common set of watersheds and associated hydrography data for the Basin that will enhance binational efforts to protect and restore the Great
Estimating watershed level nonagricultural pesticide use from golf courses using geospatial methods
Fox, G.A.; Thelin, G.P.; Sabbagh, G.J.; Fuchs, J.W.; Kelly, I.D.
2008-01-01
Limited information exists on pesticide use for nonagricultural purposes, making it difficult to estimate pesticide loadings from nonagricultural sources to surface water and to conduct environmental risk assessments. A method was developed to estimate the amount of pesticide use on recreational turf grasses, specifically golf course turf grasses, for watersheds located throughout the conterminous United States (U.S.). The approach estimates pesticide use: (1) based on the area of recreational turf grasses (used as a surrogate for turf associated with golf courses) within the watershed, which was derived from maps of land cover, and (2) from data on the location and average treatable area of golf courses. The area of golf course turf grasses determined from these two methods was used to calculate the percentage of each watershed planted in golf course turf grass (percent crop area, or PCA). Turf-grass PCAs derived from the two methods were used with recommended application rates provided on pesticide labels to estimate total pesticide use on recreational turf within 1,606 watersheds associated with surface-water sources of drinking water. These pesticide use estimates made from label rates and PCAs were compared to use estimates from industry sales data on the amount of each pesticide sold for use within the watershed. The PCAs derived from the land-cover data had an average value of 0.4% of a watershed with minimum of 0.01% and a maximum of 9.8%, whereas the PCA values that are based on the number of golf courses in a watershed had an average of 0.3% of a watershed with a minimum of <0.01% and a maximum of 14.2%. Both the land-cover method and the number of golf courses method produced similar PCA distributions, suggesting that either technique may be used to provide a PCA estimate for recreational turf. The average and maximum PCAs generally correlated to watershed size, with the highest PCAs estimated for small watersheds. Using watershed specific PCAs, combined with label rates, resulted in greater than two orders of magnitude over-estimation of the pesticide use compared to estimates from sales data. ?? 2008 American Water Resources Association.
Hydrogeology of the upper and middle Verde River watersheds, central Arizona
Blasch, Kyle W.; Hoffmann, John P.; Graser, Leslie F.; Bryson, Jeannie R.; Flint, Alan L.
2006-01-01
The upper and middle Verde River watersheds in central Arizona are primarily in Yavapai County, which in 1999 was determined to be the fastest growing rural county in the United States; by 2050 the population is projected to more than double its current size (132,000 in 2000). This study combines climatic, surface-water, ground-water, water-chemistry, and geologic data to describe the hydrogeologic systems within the upper and middle Verde River watersheds and to provide a conceptual understanding of the ground-water flow system. The study area includes the Big Chino and Little Chino subbasins in the upper Verde River watershed and the Verde Valley subbasin in the middle Verde Rive watershed...more...A geochemical mixing model was used to quantify fractions of ground-water sources to the Verde River from various parts of the study area. Most of the water in the uppermost 0.2 mile of the Verde River is from the Little Chino subbasin, and the remainder is from the Big Chino subbasin. Discharge from a system of springs increases base flow to about 17 cubic feet per second within the next 2 miles of the river. Ground water that discharges at these springs is derived from the western part of the Coconino Plateau, from the Big Chino subbasin, and from the Little Chino subbasin. More...
Stough-Hunter, Anjel; Lekies, Kristi S; Donnermeyer, Joseph F
2014-12-01
Little research has considered how residents' perceptions of their local environment may interact with efforts to increase environmental concern, particularly in areas in need of remediation. This study examined the process by which local environmental action may affect environmental concern. A model was presented for exploring the effects of community-based watershed organizations (CWOs) on environmental concern that also incorporates existing perceptions of the local environment. Survey data were collected from area residents in two watersheds in southwestern Pennsylvania, USA, an area affected by abandoned mine drainage. The findings suggest that residents' perceptions of local water quality and importance of improving water quality are important predictors of level of environmental concern and desire for action; however, in this case, having an active or inactive CWO did not influence these perceptions. The implications of these findings raise important questions concerning strategies and policy making around environmental remediation at the local level.
Lizarraga, Joy S.; Ockerman, Darwin J.
2010-01-01
The U.S. Geological Survey (USGS), in cooperation with the San Antonio River Authority, the Evergreen Underground Water Conservation District, and the Goliad County Groundwater Conservation District, configured, calibrated, and tested a watershed model for a study area consisting of about 2,150 square miles of the lower San Antonio River watershed in Bexar, Guadalupe, Wilson, Karnes, DeWitt, Goliad, Victoria, and Refugio Counties in south-central Texas. The model simulates streamflow, evapotranspiration (ET), and groundwater recharge using rainfall, potential ET, and upstream discharge data obtained from National Weather Service meteorological stations and USGS streamflow-gaging stations. Additional time-series inputs to the model include wastewater treatment-plant discharges, withdrawals for cropland irrigation, and estimated inflows from springs. Model simulations of streamflow, ET, and groundwater recharge were done for 2000-2007. Because of the complexity of the study area, the lower San Antonio River watershed was divided into four subwatersheds; separate HSPF models were developed for each subwatershed. Simulation of the overall study area involved running simulations of the three upstream models, then running the downstream model. The surficial geology was simplified as nine contiguous water-budget zones to meet model computational limitations and also to define zones for which ET, recharge, and other water-budget information would be output by the model. The model was calibrated and tested using streamflow data from 10 streamflow-gaging stations; additionally, simulated ET was compared with measured ET from a meteorological station west of the study area. The model calibration is considered very good; streamflow volumes were calibrated to within 10 percent of measured streamflow volumes. During 2000-2007, the estimated annual mean rainfall for the water-budget zones ranged from 33.7 to 38.5 inches per year; the estimated annual mean rainfall for the entire watershed was 34.3 inches. Using the HSPF model it was estimated that for 2000-2007, less than 10 percent of the annual mean rainfall on the study watershed exited the watershed as streamflow, whereas about 82 percent, or an average of 28.2 inches per year, exited the watershed as ET. Estimated annual mean groundwater recharge for the entire study area was 3.0 inches, or about 9 percent of annual mean rainfall. Estimated annual mean recharge was largest in water-budget zone 3, the zone where the Carrizo Sand outcrops. In water-budget zone 3, the estimated annual mean recharge was 5.1 inches or about 15 percent of annual mean rainfall. Estimated annual mean recharge was smallest in water-budget zone 6, about 1.1 inches or about 3 percent of annual mean rainfall. The Cibolo Creek subwatershed and the subwatershed of the San Antonio River upstream from Cibolo Creek had the largest and smallest basin yields, about 4.8 inches and 1.2 inches, respectively. Estimated annual ET and annual recharge generally increased with increasing annual rainfall. Also, ET was larger in zones 8 and 9, the most downstream zones in the watershed. Model limitations include possible errors related to model conceptualization and parameter variability, lack of data to quantify certain model inputs, and measurement errors. Uncertainty regarding the degree to which available rainfall data represent actual rainfall is potentially the most serious source of measurement error.
Kari, Fatimah Binti; Masud, Muhammad Mehedi; Yahaya, Siti Rohani Binti; Saifullah, Md Khaled
2016-03-01
"Indigenous people" have been acknowledged as among the poorest and most socio-economically and culturally marginalized all over the world. This paper explores the socio-economic status of the indigenous people and their poverty profile within watershed and environmentally protected areas in Peninsular Malaysia. The findings of the study indicate that the "indigenous community" is likely to be poor if they live in environmentally sensitive and unprotected areas as compared to families under the new resettlement scheme. Inadequate access to basic education and employment contributed significantly to their poor economic status. The findings further reveal that the indigenous community is facing difficulties in receiving access and support in terms of basic needs such as housing, education, economic livelihood, and other social infrastructure. Moreover, the regulatory structure for the management of watershed areas as well as the emphasis for commodity crops such as palm oil and natural rubber have indirectly contributed toward the poverty level of the indigenous people.
Priority and construction sites of water storage in a watershed in response to climate change
NASA Astrophysics Data System (ADS)
Lin, Cheng-Yu; Zhang, Wen-Yan; Lin, Chao-Yuan
2014-05-01
Taiwan is located at the Eastern Asia Monsoon climate zone. Typhoons and/or convectional rains occur frequently and result in high intensity storms in the summer season. Once the detention facilities are shortage or soil infiltration rate become worse in a watershed due to land use, surface runoff is easily to concentrate and threaten the protected areas. Therefore, it is very important to examine the functionality of water storage for a watershed. The purpose of this study is to solve the issue of flooding in the Puzi Creek. A case study of Yizen Bridge Watershed, in which the SCS curve number was used as an index to extract the spatial distribution of the strength of water storage, and the value of watershed mean CN along the main channel was calculated using area-weighting method. Therefore, the hotspot management sites were then derived and the priority method was applied to screen the depression sites for the reference of management authorities in detention ponds placement. The results show that the areas of subzone A with the characteristics of bad condition in topography and soil, which results in poor infiltration. However, the areas are mostly covered with forest and are difficult to create the artificial water storage facilities. Detention dams are strongly recommended at the site of depression in the river channel to decrease discharge velocity and reduce impact from flood disaster. The areas of subzone B are mainly located at the agriculture slope land. The topographic depressions in the farmland are the suitable places to construct the farm ponds for the use of flood detention and sediment deposition in the rainy seasons and irrigation in the dry seasons. Areas of subzone C are mainly occupied the gentle slope land with a better ability in water storage due to low CN value. Farm ponds constructed in the riparian to bypass the nearby river channel can create multifunctional wetland to effectively decrease the peak discharge in the downstream during storm events. Depression storages are based on additional runoff obtained from CN calculation. Strategies mentioned in this study can be provided as references of climate change adaptions for related authorities.
Huiliang, Wang; Zening, Wu; Caihong, Hu; Xinzhong, Du
2015-09-01
Nonpoint source (NPS) pollution is considered as the main reason for water quality deterioration; thus, to quantify the NPS loads reliably is the key to implement watershed management practices. In this study, water quality and NPS loads from a watershed with limited data availability were studied in a mountainous area in China. Instantaneous water discharge was measured through the velocity-area method, and samples were taken for water quality analysis in both flood and nonflood days in 2010. The streamflow simulated by Hydrological Simulation Program-Fortran (HSPF) from 1995 to 2013 and a regression model were used to estimate total annual loads of various water quality parameters. The concentrations of total phosphorus (TP) and total nitrogen (TN) were much higher during the flood seasons, but the concentrations of ammonia nitrogen (NH3-N) and nitrate nitrogen (NO3-N) were lower during the flood seasons. Nevertheless, only TP concentration was positively correlated with the flow rate. The fluctuation of annual load from this watershed was significant. Statistical results indicated the significant contribution of pollutant fluxes during flood seasons to annual fluxes. The loads of TP, TN, NH3-N, and NO3-N in the flood seasons were accounted for 58-85, 60-82, 63-88, 64-81% of the total annual loads, respectively. This study presented a new method for estimation of the water and NPS loads in the watershed with limited data availability, which simplified data collection to watershed model and overcame the scale problem of field experiment method.
Streamflow, sediment and carbon transport from a Himalayan watershed
NASA Astrophysics Data System (ADS)
Sharma, P.; Rai, S. C.
2004-04-01
Rivers indeed serve an important role in the carbon fluxes being recognized as a major component to regional and global environmental change. The present study focuses the sediment and carbon transports in a Himalayan watershed (elevational range 300-2650 m asl, area of 3014 ha) at Sikkim, India. The watershed has five perennial streams, all attain significant size during rainy season. The micro-watershed for each perennial stream has a mosaic distribution of land-use practices, viz. forests, agroforestry, agriculture and wastelands. The average discharge in the Rinjikhola, the watershed outlet was 840-850 l s -1 in summer season that increased by 5-6 times in rainy season. Sediment concentration varied distinctly with seasons in different streams and the outlet of the watershed. The soil loss rate from the total watershed ranged from 6 to 7 t ha -1 yr -1 that accounts to a net loss of 833 t yr -1 organic carbon, and 2025 t yr -1 dissolved organic carbon from the watershed, and more than 90% of soil losses were attributable to open cropped area. The stream discharge, soil and carbon loss and precipitation partitioning through different pathways in forest and agroforestry land-use suggest that these land-uses promote conservation of soil and carbon. It is emphasized that a good understanding of carbon transfer through overland flow and discharge is important for policy decisions and management of soil and carbon loss of a Himalayan watershed as it is very sensitive to land-use/cover changes. Therefore, the conversion of forest to agricultural land should be reversed. Agroforestry systems should be included in agricultural land in mountainous regions.
NASA Astrophysics Data System (ADS)
Regina, J. A.; Ogden, F. L.
2014-12-01
Hydrological processes in the humid tropics are poorly understood and an important topic when it comes to watershed management in the seasonal tropics. The Smithsonian Tropical Research Institute, Panama Canal Watershed Experiment, Agua Salud Project, seeks to understand these processes and quantify the long-term effects of different land cover and uses across the Panama Canal Watershed. One question posed by this project concerns the hydrologic role of fire in tropical environments. Within the Panama Canal Watershed, fire has seen widespread use among agriculturalists. This study focused on a monoculture invasive grass (Saccharum spontaneum) catchment. Specifically, the effects of significant wildfire events on hydrological processes in the catchment were analyzed. The catchment is within Panama's protected Soberania National Park, which is part of the greater Panama Canal Watershed. Installed instrumentation includes a rain gauge cluster, a two-stage v-notch weir, atmometer and an assortment of meteorological and automated geochemical sampling systems. Spatial, rainfall, runoff and ET data across the catchment is available from 2009-2013. Various hydrologic characteristics, such as runoff ratio, peak flow per unit area, time to peak, runoff duration, and leaf area index, from before and after the events were compared. These characteristics are related to rates of ground water recharge and the occurrence of flash floods. This study provides a baseline from which the potential impacts of fire on hydrological processes in tropical environments can be analyzed.
Linking ecosystem service supply to stakeholder concerns on ...
Policies to protect coastal resources may lead to greater social, economic, and ecological returns when they consider potential co-benefits and trade-offs on land. In Guánica Bay watershed, Puerto Rico, a watershed management plan is being implemented to restore declining quality of coral reefs due to sediment and nutrient runoff. However, recent stakeholder workshops indicated uncertainty about benefits for the local community. A total of 19 metrics were identified to capture stakeholder concerns, including 15 terrestrial ecosystem services in the watershed and 4 metrics in the coastal zone. Ecosystem service production functions were applied to quantify and map ecosystem service supply in 1) the Guánica Bay watershed and 2) a highly engineered upper multi-watershed area connected to the lower watershed via a series of reservoirs and tunnels. These two watersheds were compared to other watersheds in Puerto Rico. Relative to other watersheds, the Upper Guánica watershed had high air pollutant removal rates, forest habitat area, biodiversity of charismatic and endangered species, but low farmland quality and low sediment retention. The Lower Guánica watershed had high rates of denitrification and high levels of marine-based recreational and fishing opportunities compared to other watersheds, but moderate to low air pollutant removal, soil carbon content, sediment and nutrient retention, and terrestrial biodiversity. Our results suggest that actions in the wat
NASA Astrophysics Data System (ADS)
Devine, S.; O'Geen, A. T.; Dahlke, H. E.
2016-12-01
Understanding climate change impacts on hydrology is especially relevant to areas already dealing with water scarcity, common in Mediterranean regions such as California (CA). For instance, warming is expected to drive up evapotranspiration (ET) fluxes from vegetation, which could impact runoff (Q) and water supply by up to 30% from CA's Sierra Nevadas by 2100. In this study, we hypothesize that the 1-2 oC increase during the 20th and early 21st centuries should have resulted in a trend of decreasing Q for a given amount of precipitation (P) due to increasing ET through time. We also hypothesize that any observed differences in watershed ET response to warming could be explained by soil controls, since Mediterranean biomes require soil moisture storage to endure dry summers. We analyzed unimpaired runoff from 10 major CA watersheds relative to P over a 110 year record and found trends of increasing P minus Q in the northern watersheds, supporting the hypothesis of mountain Q vulnerability to warming but not in the central and southern watersheds. This may be partly due to the faster rates of summertime warming we observed in the northern watersheds when potential ET is highest. Analysis of several soil investigations in the study area on bioclimosequences suggests that these inter-watershed differences in P minus Q may also be due to soils. Soils formed from volcanic rocks, which are more prevalent in the northern watersheds, tend to have higher clay contents and water holding capacity. Moreover, the higher elevation central and southern watersheds were more widely glaciated throughout the Pleistocene, resulting in a wider extent of scoured landscapes and soils shallow to hard bedrock. Thus, the northern watershed ET flux could have previously been temperature constrained with untapped soil moisture storage. Going forward, an analysis is planned to quantify the extent of various soil-vegetation-climate zones. For each zone, we will build simple water balance models to estimate watershed ET response sensitivity. This should help resolve whether or not soil development is regulating hydrologic response to climate change. However, from an ecological resilience point of view, the southern watersheds may be the most sensitive. Lack of hydrologic response suggests that an upward biome shift may be ongoing or imminent there.
Evaluating sources and processing of nonpoint source nitrate in a small suburban watershed in China
NASA Astrophysics Data System (ADS)
Han, Li; Huang, Minsheng; Ma, Minghai; Wei, Jinbao; Hu, Wei; Chouhan, Seema
2018-04-01
Identifying nonpoint sources of nitrate has been a long-term challenge in mixed land-use watershed. In the present study, we combine dual nitrate isotope, runoff and stream water monitoring to elucidate the nonpoint nitrate sources across land use, and determine the relative importance of biogeochemical processes for nitrate export in a small suburban watershed, Longhongjian watershed, China. Our study suggested that NH4+ fertilizer, soil NH4+, litter fall and groundwater were the main nitrate sources in Longhongjian Stream. There were large changes in nitrate sources in response to season and land use. Runoff analysis illustrated that the tea plantation and forest areas contributed to a dominated proportion of the TN export. Spatial analysis illustrated that NO3- concentration was high in the tea plantation and forest areas, and δ15N-NO3 and δ18O-NO3 were enriched in the step ponds. Temporal analysis showed high NO3- level in spring, and nitrate isotopes were enriched in summer. Study as well showed that the step ponds played an important role in mitigating nitrate pollution. Nitrification and plant uptake were the significant biogeochemical processes contributing to the nitrogen transformation, and denitrification hardly occurred in the stream.
Sowah, R; Zhang, H; Radcliffe, D; Bauske, E; Habteselassie, M Y
2014-11-01
To determine the impact of septic systems on water quality and in so doing identify watershed level characteristics that influence septic system impact. Water samples were collected from streams in 24 well-characterized watersheds during baseflow to analyse for the levels of faecal indicators Escherichia coli and enterococci. The watersheds represent a gradient of land-use conditions from low to high density of septic systems, as well as developed to undeveloped uses. Our findings indicate statistically significant interaction between septic density and season for enterococci count (P = 0·005) and stream yield (P = 0·04). Seasonal variations in bacterial count and stream yield were also observed, with significant differences between spring-winter and summer-winter. Results from multiple linear regression models suggest that watershed characteristics (septic system density, median distance of septic systems to stream, per cent developed area and forest cover) and water temperature could explain approximately half (R(2) = 0·50) of the variability in bacterial count and yield in spring and summer. There is a significant positive relationship between septic system density and faecal pollution levels. However, this relationship is season dependent and is influenced by watershed level characteristics such as median distance of septic systems from streams, per cent developed area and forest cover. This study confirms the significant impact of septic systems on faecal pollution during baseflow and provides the tools that will enable effective pollution monitoring at the watershed scale. © 2014 The Society for Applied Microbiology.
NASA Astrophysics Data System (ADS)
Syed, N. H.; Rehman, A. A.; Hussain, D.; Ishaq, S.; Khan, A. A.
2017-11-01
Morphometric analysis is vital for any watershed investigation and it is inevitable for flood risk assessment in sub-watershed basins. Present study undertaken to carry out critical evaluation and assessment of sub watershed morphological parameters for flood risk assessment of Central Karakorum National Park (CKNP), where Geographical information system and remote sensing (GIS & RS) approach used for quantifying the parameter and mapping of sub watershed units. ASTER DEM used as a geo-spatial data for watershed delineation and stream network. Morphometric analysis carried out using spatial analyst tool of ArcGIS 10.2. The parameters included were bifurcation ratio (Rb), Drainage Texture (Rt), Circulatory ratio (Rc), Elongated ratio (Re), Drainage density (Dd), Stream Length (Lu), Stream order (Su), Slope and Basin length (Lb) have calculated separately. The analysis revealed that the stream order varies from order 1 to 6 and the total numbers of stream segments of all orders were 52. Multi criteria analysis process used to calculate the risk factor. As an accomplished result, map of sub watershed prioritization developed using weighted standardized risk factor. These results helped to understand sensitivity of flush floods in different sub watersheds of the study area and leaded to better management of the mountainous regions in prospect of flush floods.
Zhai, De-Li; Cannon, Charles H; Dai, Zhi-Cong; Zhang, Cui-Ping; Xu, Jian-Chu
2015-01-01
Hainan, the largest tropical island in China, belongs to the Indo-Burma biodiversity hotspot. The Changhua watershed is a center of endemism for plants and birds and the cradle of Hainan's main rivers. However, this area has experienced recent and ongoing deforestation and habitat fragmentation. To quantify habitat loss and fragmentation of natural forests, as well as the land-cover changes in the Changhua watershed, we analyzed Landsat images obtained in 1988, 1995, and 2005. Land-cover dynamics analysis showed that natural forests increased in area (97,909 to 104,023 ha) from 1988 to 1995 but decreased rapidly to 76,306 ha over the next decade. Rubber plantations increased steadily throughout the study period while pulp plantations rapidly expanded after 1995. Similar patterns of land cover change were observed in protected areas, indicating a lack of enforcement. Natural forests conversion to rubber and pulp plantations has a general negative effect on biodiversity, primarily through habitat fragmentation. The fragmentation analysis showed that natural forests area was reduced and patch number increased, while patch size and connectivity decreased. These land-cover changes threatened local biodiversity, especially island endemic species. Both natural forests losses and fragmentation should be stopped by strict enforcement to prevent further damage. Preserving the remaining natural forests and enforcing the status of protected areas should be a management priority to maximize the watershed's biodiversity conservation value.
NASA Astrophysics Data System (ADS)
Leta, O. T.; Dulai, H.; El-Kadi, A. I.
2017-12-01
Upland soil erosion and sedimentation are the main threats for riparian and coastal reef ecosystems in Pacific islands. Here, due to small size of the watersheds and steep slope, the residence time of rainfall runoff and its suspended load is short. Fagaalu bay, located on the island of Tutuila (American Samoa) has been identified as a priority watershed, due to degraded coral reef condition and reduction of stream water quality from heavy anthropogenic activity yielding high nutrients and sediment loads to the receiving water bodies. This study aimed to estimate the sediment yield to the Fagaalu stream and assess the impact of Best Management Practices (BMP) on sediment yield reduction. For this, the Soil and Water Assessment Tool (SWAT) model was applied, calibrated, and validated for both daily streamflow and sediment load simulation. The model also estimated the sediment yield contributions from existing land use types of Fagaalu and identified soil erosion prone areas for introducing BMP scenarios in the watershed. Then, three BMP scenarios, such as stone bund, retention pond, and filter strip were treated on bare (quarry area), agricultural, and shrub land use types. It was found that the bare land with quarry activity yielded the highest annual average sediment yield of 133 ton per hectare (t ha-1) followed by agriculture (26.1 t ha-1) while the lowest sediment yield of 0.2 t ha-1 was estimated for the forested part of the watershed. Additionally, the bare land area (2 ha) contributed approximately 65% (207 ha) of the watershed's sediment yield, which is 4.0 t ha-1. The latter signifies the high impact as well as contribution of anthropogenic activity on sediment yield. The use of different BMP scenarios generally reduced the sediment yield to the coastal reef of Fagaalu watershed. However, treating the quarry activity area with stone bund showed the highest sediment yield reduction as compared to the other two BMP scenarios. This study provides an estimate of the impact that each BMP has on specific land use and Fagaalu's reef. It also offers information that may be useful for the coastal water resource management and mitigation measures to reduce sediment yield of the study site and similar areas.
Cloud GIS Based Watershed Management
NASA Astrophysics Data System (ADS)
Bediroğlu, G.; Colak, H. E.
2017-11-01
In this study, we generated a Cloud GIS based watershed management system with using Cloud Computing architecture. Cloud GIS is used as SAAS (Software as a Service) and DAAS (Data as a Service). We applied GIS analysis on cloud in terms of testing SAAS and deployed GIS datasets on cloud in terms of DAAS. We used Hybrid cloud computing model in manner of using ready web based mapping services hosted on cloud (World Topology, Satellite Imageries). We uploaded to system after creating geodatabases including Hydrology (Rivers, Lakes), Soil Maps, Climate Maps, Rain Maps, Geology and Land Use. Watershed of study area has been determined on cloud using ready-hosted topology maps. After uploading all the datasets to systems, we have applied various GIS analysis and queries. Results shown that Cloud GIS technology brings velocity and efficiency for watershed management studies. Besides this, system can be easily implemented for similar land analysis and management studies.
Mars, J.C.; Crowley, J.K.
2003-01-01
Remotely sensed hyperspectral and digital elevation data from southeastern Idaho are combined in a new method to assess mine waste contamination. Waste rock from phosphorite mining in the area contains selenium, cadmium, vanadium, and other metals. Toxic concentrations of selenium have been found in plants and soils near some mine waste dumps. Eighteen mine waste dumps and five vegetation cover types in the southeast Idaho phosphate district were mapped by using Airborne Visible-Infrared Imaging Spectrometer (AVIRIS) imagery and field data. The interaction of surface water runoff with mine waste was assessed by registering the AVIRIS results to digital elevation data, enabling determinations of (1) mine dump morphologies, (2) catchment watershed areas above each mine dump, (3) flow directions from the dumps, (4) stream gradients, and (5) the extent of downstream wetlands available for selenium absorption. Watersheds with the most severe selenium contamination, such as the South Maybe Canyon watershed, are associated with mine dumps that have large catchment watershed areas, high stream gradients, a paucity of downstream wetlands, and dump forms that tend to obstruct stream flow. Watersheds associated with low concentrations of dissolved selenium, such as Angus Creek, have mine dumps with small catchment watershed areas, low stream gradients, abundant wetlands vegetation, and less obstructing dump morphologies. ?? 2002 Elsevier Science Inc. All rights reserved.
A study of dissolved organic carbon and nitrate export in Catskill Mountain watersheds
NASA Astrophysics Data System (ADS)
Son, K.; Moore, K. E.; Lin, L.; Schneiderman, E. M.; Band, L. E.
2016-12-01
Watersheds in the Catskill Mountain region of New York State have historically experienced soil and stream acidification due to deposition of acidic compounds created from atmospheric SO2 and NOx. Recent studies in this region, and elsewhere in North America and Europe, have shown increases in dissolved organic carbon (DOC) in streams and lakes. Watersheds in the Catskills are the major source of drinking water for New York City and other communities in the region. Due to use of chlorine for disinfection, there is potential for the increase in DOC to lead to increased levels of disinfection byproducts in treated drinking water. Therefore, developing an improved understanding of the sources, fate and transport mechanisms, and export patterns for nitrate and DOC is important for informing watershed and water supply management. In this study, we analyzed the relationships between watershed characteristics, nitrate, and DOC for 12 gauged streams in the Neversink River watershed. Watershed characteristics included topography (elevation, slope, topographic wetness index), vegetation (leaf area index, species composition), soil (soil hydraulic parameters, soil carbon, wetland soil), atmospheric deposition (SO2, NOx), and climate (precipitation, temperature). Our preliminary analysis showed that both watershed slope and baseflow ratio are negatively correlated with annual median DOC concentration. At Biscuit Brook in the Neversink watershed, annual precipitation explained about 25% of annual DOC median concentration. DOC concentration was highly correlated with storm runoff in spring, summer, and fall, but stream nitrate concentration was weakly correlated with storm runoff in most seasons except summer when it was highly correlated with baseflow. We also applied a process-based ecohydrologic model (Regional Hydrologic Ecologic System Simulation, RHESSys) to the Biscuit Brook watershed to explore sources of nitrate and DOC and their movement within the watershed. We expect that this study will increase our understanding of how, when, and where DOC and nitrate are stored and transported to streams, as well as give insights into the key controls on nitrate and DOC processes in Catskill Mountain watersheds.
On the connection of permafrost and debris flow activity in Austria
NASA Astrophysics Data System (ADS)
Huber, Thomas; Kaitna, Roland
2016-04-01
Debris flows represent a severe hazard in alpine regions and typically result from a critical combination of relief energy, water, and sediment. Hence, besides water-related trigger conditions, the availability of abundant sediment is a major control on debris flows activity in alpine regions. Increasing temperatures due to global warming are expected to affect periglacial regions and by that the distribution of alpine permafrost and the depth of the active layer, which in turn might lead to increased debris flow activity and increased interference with human interests. In this contribution we assess the importance of permafrost on documented debris flows in the past by connecting the modeled permafrost distribution with a large database of historic debris flows in Austria. The permafrost distribution is estimated based on a published model approach and mainly depends of altitude, relief, and exposition. The database of debris flows includes more than 4000 debris flow events in around 1900 watersheds. We find that 27 % of watersheds experiencing debris flow activity have a modeled permafrost area smaller than 5 % of total area. Around 7 % of the debris flow prone watersheds have an area larger than 5 %. Interestingly, our first results indicate that watersheds without permafrost experience significantly less, but more intense debris flow events than watersheds with modeled permafrost occurrence. Our study aims to contribute to a better understanding of geomorphic activity and the impact of climate change in alpine environments.
NASA Astrophysics Data System (ADS)
Zhu, Hongchun; Zhao, Yipeng; Liu, Haiying
2018-04-01
Scale is the basic attribute for expressing and describing spatial entity and phenomena. It offers theoretical significance in the study of gully structure information, variable characteristics of watershed morphology, and development evolution at different scales. This research selected five different areas in China's Loess Plateau as the experimental region and used DEM data at different scales as the experimental data. First, the change rule of the characteristic parameters of the data at different scales was analyzed. The watershed structure information did not change along with a change in the data scale. This condition was proven by selecting indices of gully bifurcation ratio and fractal dimension as characteristic parameters of watershed structure information. Then, the change rule of the characteristic parameters of gully structure with different analysis scales was analyzed by setting the scale sequence of analysis at the extraction gully. The gully structure of the watershed changed with variations in the analysis scale, and the change rule was obvious when the gully level changed. Finally, the change rule of the characteristic parameters of the gully structure at different areas was analyzed. The gully fractal dimension showed a significant numerical difference in different areas, whereas the variation of the gully branch ratio was small. The change rule indicated that the development degree of the gully obviously varied in different regions, but the morphological structure was basically similar.
NASA Astrophysics Data System (ADS)
Zhu, Hongchun; Zhao, Yipeng; Liu, Haiying
2018-06-01
Scale is the basic attribute for expressing and describing spatial entity and phenomena. It offers theoretical significance in the study of gully structure information, variable characteristics of watershed morphology, and development evolution at different scales. This research selected five different areas in China's Loess Plateau as the experimental region and used DEM data at different scales as the experimental data. First, the change rule of the characteristic parameters of the data at different scales was analyzed. The watershed structure information did not change along with a change in the data scale. This condition was proven by selecting indices of gully bifurcation ratio and fractal dimension as characteristic parameters of watershed structure information. Then, the change rule of the characteristic parameters of gully structure with different analysis scales was analyzed by setting the scale sequence of analysis at the extraction gully. The gully structure of the watershed changed with variations in the analysis scale, and the change rule was obvious when the gully level changed. Finally, the change rule of the characteristic parameters of the gully structure at different areas was analyzed. The gully fractal dimension showed a significant numerical difference in different areas, whereas the variation of the gully branch ratio was small. The change rule indicated that the development degree of the gully obviously varied in different regions, but the morphological structure was basically similar.
Messinger, Terence
2003-01-01
During storms when rainfall intensity exceeded about 1 inch per hour, peak unit runoff from the Unnamed Tributary (surface-mined and filled) Watershed exceeded peak unit runoff from the Spring Branch (unmined) Watershed in the Ballard Fork Watershed in southern West Virginia. During most storms, those with intensity less than about 1 inch per hour, peak unit (area-normalized) flows were greater from the Spring Branch Watershed than the Unnamed Tributary Watershed. One storm that produced less than an inch of rain before flow from the previous storm had receded caused peak unit flow from the Unnamed Tributary Watershed to exceed peak unit flow from the Spring Branch Watershed. Peak unit flow was usually similar in Spring Branch and Ballard Fork. Peak unit flows are expected to decrease with increasing watershed size in homogeneous watersheds; drainage area and proportion of the three watersheds covered by valley fills are 0.19 square mile (mi?) and 44 percent for the Unnamed Tributary Watershed, 0.53 mi? and 0 percent for the Spring Branch Watershed, and 2.12 mi? and 12 percent for the Ballard Fork Watershed. Following all storms with sufficient rainfall intensity, about 0.25 inches per hour, the storm hydrograph from the Unnamed Tributary Watershed showed a double peak, as a sharp initial rise was followed by a decrease in flow and then a delayed secondary peak of water that had apparently flowed through the valley fill. Hortonian (excess overland) flow may be important in the Unnamed Tributary Watershed during intense storms, and may cause the initial peak on the rising arm of storm hydrographs; the water composing the initial peaks may be conveyed by drainage structures on the mine. Ballard Fork and Spring Branch had hydrographs with single peaks, typical of elsewhere in West Virginia. During all storms with 1-hour rainfall greater than 0.75 inches or 24-hour rainfall greater than 1.75 inches during which all stream gages recorded a complete record, the Unnamed Tributary yielded the most total unit flow. In three selected major storms, total unit flow from the Unnamed Tributary during recessions exceeded storm flow, and its total unit flow was greatest among the streams during all three recessions. Runoff patterns from the mined watershed are influenced by the compaction of soils on the mine, the apparent low maximum rate of infiltration into the valley fill compared to that in the unmined, forested watershed, storage of water in the valley fill, and the absence of interception from trees and leaf litter. No storms during this study produced 1-hour or 24-hour rainfall in excess of the 5-year return period, and streamflow during this study never exceeded a magnitude equivalent to the 1.5-year return period; relative peak unit flow among the three streams in this study could be different in larger storms. Rainfall-runoff relations on altered landscapes are site-specific, and aspects of mining and reclamation practice that affect storm response may vary among mines.
Capel, P.D.; McCarthy, K.A.; Barbash, J.E.
2008-01-01
This paper is an introduction to the following series of papers that report on in-depth investigations that have been conducted at five agricultural study areas across the United States in order to gain insights into how environmental processes and agricultural practices interact to determine the transport and fate of agricultural chemicals in the environment. These are the first study areas in an ongoing national study. The study areas were selected, based on the combination of cropping patterns and hydrologic setting, as representative of nationally important agricultural settings to form a basis for extrapolation to unstudied areas. The holistic, watershed-scale study design that involves multiple environmental compartments and that employs both field observations and simulation modeling is presented. This paper introduces the overall study design and presents an overview of the hydrology of the five study areas. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.
The contribution of sediment from forested areas of the Chesapeake Bay Watershed
NASA Astrophysics Data System (ADS)
Gellis, A.; Brakebill, J.
2012-12-01
Fine-grained sediment is a major pollutant in the Chesapeake Bay and its receiving waters. Sediment budget studies have been conducted in small basins draining to the Bay over the last decade to understand the important sources of fine-grained sediment, quantify erosion rates, and determine sediment yields. Sediment budget approaches include modeling (SPARROW), sediment fingerprinting, and quantifying upland rates of erosion (Cesium-137). SPARROW model results indicate that forests deliver between 2 to 8% of the total sediment to the Bay. Sediment-fingerprinting results from small watershed studies indicate that forests contribute between 13 to 29 % of the sediment. The Cesium-137 technique was used to quantify soil redistribution (erosion and deposition) rates for forested areas in the Linganore Creek (146 km2) watershed which drains the Piedmont Physiographic Province. Average forest erosion rates measured in 2009 for Linganore Creek using Cesium-137 were 2.6 t/ha/yr. With 27% of the Linganore Creek watershed in forest, over 10,300 may be eroded off of forested lands which is more than the average annual suspended-sediment load (8,050 Mg/yr) in Linganore Creek, indicating that much of the eroded forest sediment goes in storage. Most of the forested areas in the Chesapeake Bay watershed were cut down for agriculture between the time of European colonization and the early 20th Century. In the late 20th century forested lands show an increase in areal extent. Although studies have not been conducted to understand why these secondary growth forests are eroding, it may involve that these forests have not fully recovered from deforestation. Soil profiles are thin, and runoff and sediment relations may have been altered, leading to high rates of erosion.
Meyer, Michael L; Huey, Greg M
2006-05-01
This study utilized telemetric systems to sample microbes and pathogens in forest, burned forest, rangeland, and urban watersheds to assess surface water quality in northern New Mexico. Four sites included remote mountainous watersheds, prairie rangelands, and a small urban area. The telemetric system was linked to dataloggers with automated event monitoring equipment to monitor discharge, turbidity, electrical conductivity, water temperature, and rainfall during base flow and storm events. Site data stored in dataloggers was uploaded to one of three types of telemetry: 1) radio in rangeland and urban settings; 2) a conventional phone/modem system with a modem positioned at the urban/forest interface; and 3) a satellite system used in a remote mountainous burned forest watershed. The major variables affecting selection of each system were site access, distance, technology, and cost. The systems were compared based on operation and cost. Utilization of telecommunications systems in this varied geographic area facilitated the gathering of hydrologic and water quality data on a timely basis.
NASA Astrophysics Data System (ADS)
Amer, R.; Ofterdinger, U.; Ruffell, A.; Donald, A.
2012-04-01
This study presents landuse/landcover (LULC) classifications of Northern Ireland in order to quantify land-use types driving chemical loading in the surface water bodies. The major LULC classes are agricultural land, bare land (mountainous areas), forest, urban areas, and water bodies. Three ENVISAT ASAR multi-look precision images acquired in 2011 and two Enhanced Thematic Mapper Plus (ETM+) acquired in 2003 were used for classification. The ASAR digital numbers were converted to backscattering coefficient (sigma nought) and enhanced using adaptive Gamma filter and Gaussian stretch. Supervised classifications of Maximum Likelihood, Mahalanobils Distance, Minimum Distance, Spectral Angel Mapper, Parallelepiped, and Winner Tercat were applied on ETM+ and ASAR images. A confusion matrix was used to evaluate the classification accuracy; the best results of ETM+ and ASAR were given by the winner classification (82.9 and 73.6 %), and maximum likelihood (81.7 and 72.5 %), respectively. Change detection was applied to identify the areas of significant changes in landuse/landcover over the last eight years. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation model was processed to extract the drainage systems and watersheds. Water quality data of the first and second order streams were extracted from 2005 survey by Geological Survey of Northern Ireland. GIS spatially distributed modelling generated maps showing the distribution of phosphorus (P), nitrate (NO3), dissolved organic carbon (DOC), and some of the trace elements including fluoride (F), calcium (Ca), aluminium (Al), iron (Fe), copper (Cu), lead (Pb), zinc (Zn), and arsenic (As) across the watersheds of the Northern Ireland were generated. The distribution of these elements was evaluated against the LULC classes and bed rock geology. Concentration of these elements was classified into normal (safe level), moderate, high, and very high based on the World Health Organization (WHO, 2011) water quality standards. The results show that P concentration is generally high across all the watersheds. NO3 is within normal range in all watersheds. DOC is within normal range in urban areas, moderate to high in agricultural lands, and high in the forest areas and bare lands. F and Fe are within safe level in all watersheds. Al, Cu, and As are high in all watersheds around the bare land LULC class which are underlain by psammite and semipelite metamorphic rocks. Ca is within normal range in most of watersheds but it is high in the south western part of the study area because of the presence of limestone bedrock. Pb and Zn are within normal range in the urban and most of the agricultural land, and high in the mountainous areas underlain by psammite and semipelite metamorphic bed rock.
Soong, David T.; Murphy, Elizabeth A.; Straub, Timothy D.
2009-01-01
The effects of stormwater detention basins with specified release rates are examined on the watershed scale with a Hydrological Simulation Program - FORTRAN (HSPF) continuous-simulation model. Modeling procedures for specifying release rates from detention basins with orifice and weir discharge configurations are discussed in this report. To facilitate future detention modeling as a tool for watershed management, a chart relating watershed impervious area to detention volume is presented. The report also presents a case study of the Blackberry Creek watershed in Kane County, Ill., a rapidly urbanizing area seeking to avoid future flood damages from increased urbanization, to illustrate the effects of various detention basin release rates on flood peaks and volumes and flood frequencies. The case study compares flows simulated with a 1996 land-use HSPF model to those simulated with four different 2020 projected land-use HSPF model scenarios - no detention, and detention basins with release rates of 0.08, 0.10, and 0.12 cubic feet per second per acre (ft3/s-acre), respectively. Results of the simulations for 15 locations, which included the downstream ends of all tributaries and various locations along the main stem, showed that a release rate of 0.10 ft3/s-acre, in general, can maintain postdevelopment 100-year peak-flood discharge at a similar magnitude to that of 1996 land-use conditions. Although the release rate is designed to reduce the 100-year peak flow, reduction of the 2-year peak flow is also achieved for a smaller proportion of the peak. Results also showed that the 0.10 ft3/s-acre release rate was less effective in watersheds with relatively high percentages of preexisting (1996) development than in watersheds with less preexisting development.
Gomez, Joshua; Vidon, Philippe; Gross, Jordan; Beier, Colin; Caputo, Jesse; Mitchell, Myron
2016-05-01
Although anthropogenic emissions of greenhouse gases (GHG: CO2, CH4, N2O) are unequivocally tied to climate change, natural systems such as forests have the potential to affect GHG concentration in the atmosphere. Our study reports GHG emissions as CO2, CH4, N2O, and CO2eq fluxes across a range of landscape hydrogeomorphic classes (wetlands, riparian areas, lower hillslopes, upper hillslopes) in a forested watershed of the Northeastern USA and assesses the usability of the topographic wetness index (TWI) as a tool to identify distinct landscape geomorphic classes to aid in the development of GHG budgets at the soil atmosphere interface at the watershed scale. Wetlands were hot spots of GHG production (in CO2eq) in the landscape owing to large CH4 emission. However, on an areal basis, the lower hillslope class had the greatest influence on the net watershed CO2eq efflux, mainly because it encompassed the largest proportion of the study watershed (54 %) and had high CO2 fluxes relative to other land classes. On an annual basis, summer, fall, winter, and spring accounted for 40, 27, 9, and 24 % of total CO2eq emissions, respectively. When compared to other approaches (e.g., random or systematic sampling design), the TWI landscape classification method was successful in identifying dominant landscape hydrogeomorphic classes and offered the possibility of systematically accounting for small areas of the watershed (e.g., wetlands) that have a disproportionate effect on total GHG emissions. Overall, results indicate that soil CO2eq efflux in the Archer Creek Watershed may exceed C uptake by live trees under current conditions.
Restore McComas Meadows; Meadow Creek Watershed, 2004-2005 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McRoberts, Heidi
2005-12-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated and cost shared with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing, planting trees in riparian areas within the meadow and its tributaries, prioritizing culverts for replacement to accommodate fish passage, and decommissioning roads tomore » reduce sediment input. During this contract period, bids were solicited and awarded for two culvert replacement projects on Doe Creek, and a tributary to Meadow Creek. Additionally, NEPA and permits were completed for the ditch restoration project within McComas Meadows. Due to delays in cultural resource surveys, the contract was not awarded for the performance of the ditch restoration. It will occur in 2005. Monitoring for project effectiveness and trends in watershed conditions was also completed. Road decommissioning monitoring, as well as stream temperature, sediment, and discharge were completed.« less
Increased variability of watershed areas in patients with high-grade carotid stenosis.
Kaczmarz, Stephan; Griese, Vanessa; Preibisch, Christine; Kallmayer, Michael; Helle, Michael; Wustrow, Isabel; Petersen, Esben Thade; Eckstein, Hans-Henning; Zimmer, Claus; Sorg, Christian; Göttler, Jens
2018-03-01
Watershed areas (WSAs) of the brain are most susceptible to acute hypoperfusion due to their peripheral location between vascular territories. Additionally, chronic WSA-related vascular processes underlie cognitive decline especially in patients with cerebral hemodynamic compromise. Despite of high relevance for both clinical diagnostics and research, individual in vivo WSA definition is fairly limited to date. Thus, this study proposes a standardized segmentation approach to delineate individual WSAs by use of time-to-peak (TTP) maps and investigates spatial variability of individual WSAs. We defined individual watershed masks based on relative TTP increases in 30 healthy elderly persons and 28 patients with unilateral, high-grade carotid stenosis, being at risk for watershed-related hemodynamic impairment. Determined WSA location was confirmed by an arterial transit time atlas and individual super-selective arterial spin labeling. We compared spatial variability of WSA probability maps between groups and assessed TTP differences between hemispheres in individual and group-average watershed locations. Patients showed significantly higher spatial variability of WSAs than healthy controls. Perfusion on the side of the stenosis was delayed within individual watershed masks as compared to a watershed template derived from controls, being independent from the grade of the stenosis and collateralization status of the circle of Willis. Results demonstrate feasibility of individual WSA delineation by TTP maps in healthy elderly and carotid stenosis patients. Data indicate necessity of individual segmentation approaches especially in patients with hemodynamic compromise to detect critical regions of impaired hemodynamics.
NASA Astrophysics Data System (ADS)
Weinberger, J. L.; Quinlan, P. T.; Martin, J.; Tartakovsky, D. M.
2013-12-01
Watershed scale estimates of evapotranspiration (ET) have proven difficult to quantify in areas of native vegetation with uncertain or unknown crop coefficients. In this study, we evaluate the water use in Quercus engelmanni and Quercus agrifolia, two species of oak native to Southern California. Thermal dissipation probes (TDPs) were installed at four locations within a 14,500 acre watershed, comprising 770 acres of Q. agrifolia woodland and 2440 acres of Q. engelmanni woodland. Installation duration ranged from 6 weeks to 14 months. The TDPs were calibrated to each species in the laboratory using limbs ranging from 2 to 5 inches in diameter. Dye was run through each limb at the end of the calibration test in order to establish a relationship between active sapwood area and limb diameter. ET measured in the field for each species was 0.15 to 0.3 times that of the reference evapotranspiration (ETo) derived from the Penman-Monteith equation, with the primary variability in the demand related to measured incident solar radiation. The total water demand for each species is estimated using the laboratory determined relationship between the active sapwood area and the diameter of the limb, and a survey of the tree diameter breast height (DBH) of each tree in the watershed. This study provides new insight into the actual water demand of two native tree species in Southern California and has serious implications for conservation plans, which are often developed using watershed models that apply ETo to all vegetation communities, regardless of actual water demand.
Ricker, Matthew C; Odhiambo, Ben K; Church, Joseph M
2008-05-01
Soil erosion is a serious problem in areas with expanding construction, agricultural production, and improper storm water management. It is important to understand the major processes affecting sediment delivery to surficial water bodies in order to tailor effective mitigation and outreach activities. This study analyzes how naturally occurring and anthropogenic influences, such as urbanization and soil disturbance on steep slopes, are reflected in the amount of soil erosion and sediment delivery within sub-watershed-sized areas. In this study, two sub-watersheds of the Rappahannock River, Horsepen Run and Little Falls Run, were analyzed using the Revised Universal Soil Loss Equation (RUSLE) and a sediment delivery ratio (SDR) to estimate annual sediment flux rates. The RUSLE/SDR analyses for Horsepen Run and Little Falls Run predicted 298 Mg/y and 234 Mg/y, respectively, but nearly identical per-unit-area sediment flux rates of 0.15 Mg/ha/y and 0.18 Mg/ha/y. Suspended sediment sampling indicated greater amounts of sediment in Little Falls Run, which is most likely due to anthropogenic influences. Field analyses also suggest that all-terrain vehicle crossings represent the majority of sediment flux derived from forested areas of Horsepen Run. The combined RUSLE/SDR and field sampling data indicate that small-scale anthropogenic disturbances (ATV trails and construction sites) play a major role in overall sediment flux rates for both basins and that these sites must be properly accounted for when evaluating sediment flux rates at a sub-watershed scale.
NASA Astrophysics Data System (ADS)
Guzman, C. D.; Admassu, S.; Derebe, A.; Yitaferu, B.; Steenhuis, T. S.
2013-12-01
The aims of this investigation are to analyze spatio-temporal variations in sediment transport to waterways in a small agricultural watershed by: (i) locating sediment sources using modeling and bio-physical scientific approaches, (ii) locating sediment sources and erosion processes through age- and gender-differentiated focus group discussions and transect walks, and (iii) linking sediment sources to changes in soil nutrient concentrations. The collected field measurements, modeling results, and community perceptions have been gathered on an area encompassing a previous study site (14 ha) on a currently larger scale (95 ha) in the Debre Mewi watershed to develop a fuller picture of the social and environmental conditions that are leading to induced or controlled erosion and gully formation. Farmers provided their perspectives on erosion processes and these were complemented by and compared to soil and water field measurements during the rainy season. Sixteen sites were selected for monitoring and measuring groundwater, soil nutrient changes, and soil depth change on the 95 ha study area, based on land use and slope angle -- half represent grazing or fallow land and half are located on cultivated land. A set of stable gullies and actively forming gullies were monitored and measured simultaneously along hillslope locations in the top, middle and bottom areas. In addition, sediment concentration samples were collected at 4 weir locations in the 95 ha watershed and also at the final outlet to this watershed. Modeling efforts emphasize steep cropland as most vulnerable, whereas community members pointed out waterlogged black soils and lower areas as vulnerable. The data demonstrate that saturated pathways in the landscape provide areas for the development and widening of gullies and that flat cropland areas experience deposition rather than erosion, while soil nutrient concentrations are decreasing upslope and increasing downslope.
NASA Astrophysics Data System (ADS)
Guzman, Christian; Dagnew, Dessalegn; Zegeye, Assefa; Tilahun, Seifu; Yitaferu, Birru; Stoof, Cathelijne; Steenhuis, Tammo
2014-05-01
The aims of this investigation are to analyze spatio-temporal variations in sediment transport to waterways in a small agricultural watershed by: (i) locating sediment sources using modeling and bio-physical scientific approaches, (ii) locating sediment sources and erosion processes through age- and gender-differentiated focus group discussions and transect walks, and (iii) linking sediment sources to changes in soil nutrient concentrations. The collected field measurements, modeling results, and community perceptions have been gathered on an area encompassing a previous study site (14 ha) on a currently larger scale (95 ha) in the Debre Mewi watershed to develop a fuller picture of the social and environmental conditions that are leading to induced or controlled erosion and gully formation. Farmers provided their perspectives on erosion processes and these were complemented by and compared to soil and water field measurements during the rainy season. Nine sites were selected for monitoring and measuring groundwater, soil nutrient changes, and soil depth change on the 95 ha study area, based on land use and slope angle -- half represent grazing or fallow land and half are located on cultivated land. A set of stable gullies and actively forming gullies were monitored and measured simultaneously along hillslope locations in the top, middle and bottom areas. In addition, sediment concentration samples were collected at 4 weir locations in the 95 ha watershed and also at the final outlet to this watershed. Modeling efforts emphasize steep cropland as most vulnerable, whereas community members pointed out waterlogged black soils and lower areas as vulnerable. The data demonstrate that saturated pathways in the landscape provide areas for the development and widening of gullies and that flat cropland areas experience deposition rather than erosion, while soil nutrient concentrations are decreasing upslope and increasing downslope.
Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, ...
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
This report provides details on the baseline ecological risk assessment conducted in support of the Remedial Investigation (RI) Report for the Melton Valley areas of the White Oak Creek watershed (WOCW). The RI presents an analysis meant to enable the US Department of Energy (DOE) to pursue a series of remedial actions resulting in site cleanup and stabilization. The ecological risk assessment builds off of the WOCW screening ecological risk assessment. All information available for contaminated sites under the jurisdiction of the US Department of Energy`s Comprehensive Environmental Response, Compensation, and Liability Act Federal Facilities Agreement within the White Oakmore » Creek (WOC) RI area has been used to identify areas of potential concern with respect to the presence of contamination posing a potential risk to ecological receptors within the Melton Valley area of the White Oak Creek watershed. The risk assessment report evaluates the potential risks to receptors within each subbasin of the watershed as well as at a watershed-wide scale. The WOC system has been exposed to contaminant releases from Oak Ridge National Laboratory and associated operations since 1943 and continues to receive contaminants from adjacent waste area groupings.« less
Identification of drought in Dhalai river watershed using MCDM and ANN models
NASA Astrophysics Data System (ADS)
Aher, Sainath; Shinde, Sambhaji; Guha, Shantamoy; Majumder, Mrinmoy
2017-03-01
An innovative approach for drought identification is developed using Multi-Criteria Decision Making (MCDM) and Artificial Neural Network (ANN) models from surveyed drought parameter data around the Dhalai river watershed in Tripura hinterlands, India. Total eight drought parameters, i.e., precipitation, soil moisture, evapotranspiration, vegetation canopy, cropping pattern, temperature, cultivated land, and groundwater level were obtained from expert, literature and cultivator survey. Then, the Analytic Hierarchy Process (AHP) and Analytic Network Process (ANP) were used for weighting of parameters and Drought Index Identification (DII). Field data of weighted parameters in the meso scale Dhalai River watershed were collected and used to train the ANN model. The developed ANN model was used in the same watershed for identification of drought. Results indicate that the Limited-Memory Quasi-Newton algorithm was better than the commonly used training method. Results obtained from the ANN model shows the drought index developed from the study area ranges from 0.32 to 0.72. Overall analysis revealed that, with appropriate training, the ANN model can be used in the areas where the model is calibrated, or other areas where the range of input parameters is similar to the calibrated region for drought identification.
Banta, J. Ryan; Lambert, Rebecca B.; Slattery, Richard N.; Ockerman, Darwin J.
2012-01-01
During the three surveys, reaches of gaining, losing, or no verifiable change in streamflow were observed in the watersheds in the study area. Reaches of generally consistent gaining or losing streamflow were identified in the Nueces, Frio, and Sabinal River watersheds. The water-quality data indicate that the streamflow, springflow, and groundwater have similar major ion chemical characteristics and generally can be categorized as a calcium-carbonate water type. Those data also indicate that the major ion chemistry was similar during the 2009 and 2010 surveys. Graphical comparisons among ratios of major ions, trace elements, and isotopes (for example, magnesium/calcium ratios to strontium isotopic ratios) indicate that samples collected from each watershed generally clustered together. Determining the source areas and other possible contributors on the basis of these data is not possible because of the small sample size of the water-quality dataset (both in number of samples and spatial distribution of samples). The different relations among the water-quality data indicate that the surface water in the different watersheds is likely influenced by differences in source areas, geochemical evolution, groundwater flow paths and residence time, local stratigraphy, or some combination thereof.
Hu, Maochuan; Sayama, Takahiro; Zhang, Xingqi; Tanaka, Kenji; Takara, Kaoru; Yang, Hong
2017-05-15
Low impact development (LID) has attracted growing attention as an important approach for urban flood mitigation. Most studies evaluating LID performance for mitigating floods focus on the changes of peak flow and runoff volume. This paper assessed the performance of LID practices for mitigating flood inundation hazards as retrofitting technologies in an urbanized watershed in Nanjing, China. The findings indicate that LID practices are effective for flood inundation mitigation at the watershed scale, and especially for reducing inundated areas with a high flood hazard risk. Various scenarios of LID implementation levels can reduce total inundated areas by 2%-17% and areas with a high flood hazard level by 6%-80%. Permeable pavement shows better performance than rainwater harvesting against mitigating urban waterlogging. The most efficient scenario is combined rainwater harvesting on rooftops with a cistern capacity of 78.5 mm and permeable pavement installed on 75% of non-busy roads and other impervious surfaces. Inundation modeling is an effective approach to obtaining the information necessary to guide decision-making for designing LID practices at watershed scales. Copyright © 2017 Elsevier Ltd. All rights reserved.
Future Climate Change Impact Assessment of River Flows at Two Watersheds of Peninsular Malaysia
NASA Astrophysics Data System (ADS)
Ercan, A.; Ishida, K.; Kavvas, M. L.; Chen, Z. R.; Jang, S.; Amin, M. Z. M.; Shaaban, A. J.
2016-12-01
Impacts of climate change on the river flows under future climate change conditions were assessed over Muda and Dungun watersheds of Peninsular Malaysia by means of a coupled regional climate model and a physically-based hydrology model utilizing an ensemble of 15 different future climate realizations. Coarse resolution GCMs' future projections covering a wide range of emission scenarios were dynamically downscaled to 6 km resolution over the study area. Hydrologic simulations of the two selected watersheds were carried out at hillslope-scale and at hourly increments.
Cohen, J.B.; Rattner, B.A.; Golden, N.H.
2003-01-01
The 'Contaminant Exposure and Effects--Terrestrial Vertebrates' (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n=2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The U.S. Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.
Cohen, Jonathan B; Rattner, Barnett A; Golden, Nancy H
2003-01-01
The "Contaminant Exposure and Effects-Terrestrial Vertebrates" (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n = 2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The US Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.
NASA Astrophysics Data System (ADS)
Rouhani, S. F. B. B.; Schaaf, C.; Douglas, E. M.; Huntington, T. G.; Kim, J.
2017-12-01
Dissolved Organic Carbon leaches from the terrestrial watersheds to serve as one of the largest sources of marine DOC. Runoff, slope, soil organic matter and land cover characteristics are the primary spatial factors controlling the variability of fluvial Dissolved Organic Carbon fluxes through the catchment. In large, more heterogeneous catchments, streamflow dissolved organic carbon dynamics are regulated by the combined effect of hydrological mechanisms and the proportion of major landscape elements, such as wetland and forested areas. A number of studies have demonstrated that the amount of wetlands, especially peatlands, controls the watershed level transport of DOC in streams.The Penobscot River Watershed is located in north-central Maine and drains into the Gulf of Maine. It is the second largest watershed in New England. The Penobscot River Watershed is primarily forested but also contains extensive bogs, marshes, and wooded swamps.Studying the spatial and temporal changes in DOC export in the Penobscot River Watershed allows us to better understand and detect carbon sinks to carbon source shifts (or vice versa) in northern forested ecosystems.The Regional Hydro-Ecological Simulation System, is a physical process based terrestrial model that has the ability to simulate both the source and transportation of DOC by combining both hydrological and ecological processes. The study is focused on simulating the DOC concentration and flux with RHESSys in the Penobscot River Watershed. The simulated results are compared with field measurements of DOC from the watershed and the model results from the LOADEST and the temporal DOC export patterns are explored. Future changes in the amount of streamflow DOC will also be investigated by using projected land cover and climate change scenarios. Incremental increases in the loss of wetland areas have been implemented to explore the sensitivity of this watershed to wetland loss and progressive changes in forested land cover have been implemented to understand the role of vegetation types to the DOC flux.The simulated daily streamflow for the period of 2004-2013 corresponded well with observed daily streamflowat USGS gauge station. in addition, the simulated DOC flux and concentration values matched well with observed data and LODEST model results.
A Case Study of Differing Effects of Urbanization on Streamflow From Two Proximate Watersheds
NASA Astrophysics Data System (ADS)
Brandes, D.; Lott, F.
2007-12-01
The effects of urbanization on streamflow from two proximate watersheds (Little Lehigh Creek (LLC) and Monocacy Creek (MC)) are investigated. Despite close similarities in rainfall, population growth, land use, imperviousness, and geology of the watersheds, streamflows at the LLC gage have changed markedly over the past 50 years, while those at the MC gage have not. In LLC, there are significant increasing trends in annual stormflow volume, annual maximum flow, and flashiness, but there are no significant trends in these measures in MC. Neither stream shows significant trends in annual baseflow volume or low flow. It appears that the distinct difference in response to urbanization of these two streams can be ascribed to differences in 1) watershed geomorphology, 2) spatial distribution, composition, and infiltration characteristics of carbonate bedrock, and 3) the spatial pattern of land development in each watershed with respect to the gage location. In regards to geomorphology, there is a steeper main channel and narrower floodplains in LLC than in MC. Carbonate soil and bedrock (primarily dolostone) are distributed throughout much of LLC watershed but only in the lower half of MC watershed; however the lower MC watershed (primarily limestone) has much more abundant sinkholes and karst features than in the LLC watershed. Finally, residential and commercial development is concentrated in the upper two thirds of the LLC watershed, where travel times are such that these areas contribute to the peak flows measured at the gage. Development is concentrated in the lower third of the MC watershed, where it has had less effect on peak flows at the gage. Overall, the study indicates that relatively subtle differences between watershed characteristics and development patterns can result in significant differences in runoff and in how streamflow regimes may change in response to urbanization.
Plant Diversity Contributions of Riparian Areas in Watersheds of the Northern Lake States, USA
P. Charles Goebel; Brain J. Palik; Kurt S. Pregitzer
2003-01-01
In most forested watersheds, riparian areas constitute a small proportion of the total land area, yet their contributions to overall plant diversity can be significant. However, little information is available on which portion of riparian areas (defined as functional ecotones comprising all fluvial landforms, including floodplains, terraces, and connecting hillslopes)...
Percentage of Protected Area Amounts within each Watershed Boundary for the Conterminous US
Abstract: This dataset uses spatial information from the Watershed Boundary Dataset (WBD, March 2011) and the Protected Areas Database of the United States (PAD-US Version 1.0). The resulting data layer, with percentages of protected areas by category, was created using the ATtI...
People and water: Exploring the social-ecological condition of watersheds of the United States
Scown, Murray W.; Flotemersch, Joseph E.; Spanbauer, Trisha L.; Eason, Tarsha; Garmestani, Ahjond; Chaffin, Brian C.
2018-01-01
A recent paradigm shift from purely biophysical towards social-ecological assessment of watersheds has been proposed to understand, monitor, and manipulate the myriad interactions between human well-being and the ecosystem services that watersheds provide. However, large-scale, quantitative studies in this endeavour remain limited. We utilised two newly developed ‘big-data’ sets—the Index of Watershed Integrity (IWI) and the Human Well-Being Index (HWBI)—to explore the social-ecological condition of watersheds throughout the conterminous U.S., and identified environmental and socio-economic influences on watershed integrity and human well-being. Mean county IWI was highly associated with ecoregion, industry-dependence, and state, in a spatially-explicit regression model (R2 = 0.77, P < 0.001), whereas HWBI was not (R2 = 0.31, P < 0.001). HWBI is likely influenced by factors not explored here, such as governance structure and formal and informal organisations and institutions. ‘Win-win’ situations in which both IWI and HWBI were above the 75th percentile were observed in much of Utah, Colorado, and New Hampshire, and lessons from governance that has resulted in desirable outcomes might be learnt from here. Eastern Kentucky and West Virginia, along with large parts of the desert southwest, had intact watersheds but low HWBI, representing areas worthy of further investigation of how ecosystem services might be utilised to improve well-being. The Temperate Prairies and Central USA Plains had widespread areas of low IWI but high HWBI, likely a result of historic exploitation of watershed resources to improve well-being, particularly in farming-dependent counties. The lower Mississippi Valley had low IWI and HWBI, which is likely related to historical (temporal) and upstream (spatial) impacts on both watershed integrity and well-being. The results emphasise the importance of considering spatial and temporal trade-offs when utilising the ecosystem services provided by watersheds to improve human well-being. PMID:29682591
People and water: Exploring the social-ecological condition of watersheds of the United States.
Scown, Murray W; Flotemersch, Joseph E; Spanbauer, Trisha L; Eason, Tarsha; Garmestani, Ahjond; Chaffin, Brian C
2017-01-01
A recent paradigm shift from purely biophysical towards social-ecological assessment of watersheds has been proposed to understand, monitor, and manipulate the myriad interactions between human well-being and the ecosystem services that watersheds provide. However, large-scale, quantitative studies in this endeavour remain limited. We utilised two newly developed 'big-data' sets-the Index of Watershed Integrity (IWI) and the Human Well-Being Index (HWBI)-to explore the social-ecological condition of watersheds throughout the conterminous U.S., and identified environmental and socio-economic influences on watershed integrity and human well-being. Mean county IWI was highly associated with ecoregion, industry-dependence, and state, in a spatially-explicit regression model (R 2 = 0.77, P < 0.001), whereas HWBI was not (R 2 = 0.31, P < 0.001). HWBI is likely influenced by factors not explored here, such as governance structure and formal and informal organisations and institutions. 'Win-win' situations in which both IWI and HWBI were above the 75 th percentile were observed in much of Utah, Colorado, and New Hampshire, and lessons from governance that has resulted in desirable outcomes might be learnt from here. Eastern Kentucky and West Virginia, along with large parts of the desert southwest, had intact watersheds but low HWBI, representing areas worthy of further investigation of how ecosystem services might be utilised to improve well-being. The Temperate Prairies and Central USA Plains had widespread areas of low IWI but high HWBI, likely a result of historic exploitation of watershed resources to improve well-being, particularly in farming-dependent counties. The lower Mississippi Valley had low IWI and HWBI, which is likely related to historical (temporal) and upstream (spatial) impacts on both watershed integrity and well-being. The results emphasise the importance of considering spatial and temporal trade-offs when utilising the ecosystem services provided by watersheds to improve human well-being.
Kalin, Latif; Hantush, Mohamed M
2009-02-01
An index based method is developed that ranks the subwatersheds of a watershed based on their relative impacts on watershed response to anticipated land developments, and then applied to an urbanizing watershed in Eastern Pennsylvania. Simulations with a semi-distributed hydrologic model show that computed low- and high-flow frequencies at the main outlet increase significantly with the projected landscape changes in the watershed. The developed index is utilized to prioritize areas in the urbanizing watershed based on their contributions to alterations in the magnitude of selected flow characteristics at two spatial resolutions. The low-flow measure, 7Q10, rankings are shown to mimic the spatial trend of groundwater recharge rates, whereas average annual maximum daily flow, QAMAX, and average monthly median of daily flows, QMMED, rankings are influenced by both recharge and proximity to watershed outlet. Results indicate that, especially with the higher resolution, areas having quicker responses are not necessarily the more critical areas for high-flow scenarios. Subwatershed rankings are shown to vary slightly with the location of water quality/quantity criteria enforcement. It is also found that rankings of subwatersheds upstream from the site of interest, which could be the main outlet or any interior point in the watershed, may be influenced by the time scale of the hydrologic processes.
Modeling and sediment study in the watershed Medjerda, Tunisia
NASA Astrophysics Data System (ADS)
Kotti, Fatma; Mahé, Gil; Habaieb, Hamadi; Dieulin, Claudine; Hermassi, Taoufik
2015-04-01
Water projects have experienced a major expansion in the late 1980s, and we now have sufficient perspective to assess their actual performance and their socio-environmental impacts (Payan, 2007). This study focuses on the great watershed of Tunisia namely Medjerda which has an area of about 23,600 km2. In the main river of Medjerda some dams have been created for water retention: Sidi Salem Dam (the largest in the country), El Aroussia dam, and others on tributaries Mellegue Bouhertma, Siliana, Beni Mtir, Lakhemess and Kasseb. Since the construction of dams, essentially Sidi Salem and Siliana, the Medjerda river has undergone significant changes in morphology. The monitoring of the flow of the major hydrological stations in the pre-estuarine zone downstream from Sidi Salem dam is used to measure the impact of the constructions on hydrological regimes: reduction in average rates, reduction in volumes sold, altered seasonal pattern, and most of all reduction of the sediment transport, which the highest values are related to extreme events. In this context, the balance of sediment monitoring appears indispensable for the quantification of sediment transport at the outlet. Our approach is to calculate a specific flow rate relative to the area of the basin for every structure built in the Medjerda watershed, from the information available on transport and sedimentation rates known, combined with contours of each sub watershed. There are about ten dams spread throughout Medjerda watershed. The methodology is primarily developed for the Mellegue dam because we have at this station a long data set from 1955 until 2005. Other stations will be studied later on. The main objective of this study is to provide a series of annual variation of theoretical contributions. These calculated values will be compared with the actual measured sedimentary series. Two cores in the sediments of the pre-estuarine area are performed to determine past variability in sediment inputs over a time series than should be about one century. The cores' analysis results show a succession of sedimentary layers that likely correspond to different flood deposits that succeeded on this site, and especially the datation of the cores shows that the selected area is a very important deposition area. This sedimentary study will help estimate the sediment dynamics to major estuaries, which is poorly known for most of the rivers of Maghreb. The reduction of the sediment supply to the sea is tipped as a major factor to be taken into account for a better understanding of the dynamics of coastal areas in the context of global climate change and sea level rise. Keywords: sediment core, Medjerda watershed, dam, hydrology, modeling, Tunisia
Code of Federal Regulations, 2010 CFR
2010-01-01
... Transportation of the U.S. House of Representatives for any watershed area in the 50 States, the Commonwealth of Puerto Rico, and the U.S. Virgin Islands if the nature of the watershed area problems dictates need for a...
Code of Federal Regulations, 2014 CFR
2014-01-01
... Transportation of the U.S. House of Representatives for any watershed area in the 50 States, the Commonwealth of Puerto Rico, and the U.S. Virgin Islands if the nature of the watershed area problems dictates need for a...
Impacts of channel deposition on the risk of flooding in a watershed
NASA Astrophysics Data System (ADS)
Ting-Yue, Hong; Chia-Ling, Chang
2017-04-01
Taiwan is located in East Asian where is always hit by typhoons. Typhoons usually bring huge amounts of rainfall and result in the problems of channel deposition. Deposition influences the functions of channel and increases the risk of flooding. The Luliao Reservoir Watershed is the case area in this study. It is the major water source for agricultural activity and domestic use. The objective of this study is to assess the possible impacts of channel deposition on the watershed environment. This study applies the Storm Water Management Model (SWMM) to predict the hydrologic responses and evaluate the risk of flooding. The results show that the decrease of cross section induced by deposition in a channel may increase the risk of flooding and impact the safety of watershed environment. Therefore, canal desilting is important in channel regulation. The discussion and analysis can be useful references for channel regulation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ha, Miae; Wu, May
Sound crop and land management strategies can maintain land productivity and improve the environmental sustainability of agricultural crop and feedstock production. This study evaluates the improvement of water sustainability through an integrated landscaping management strategy, where landscaping design, land management operations, crop systems, and agricultural best management practices (BMPs) play equal roles. The strategy was applied to the watershed of the South Fork Iowa River in Iowa, with a focus on implementing riparian buffers and converting low productivity land to provide cellulosic biomass while benefiting soil and water quality. The Soil and Water Assessment Tool (SWAT) was employed to simulatemore » the impact of integrated landscape design on nutrients, suspended sediments, and flow on the watershed and subbasin scales. First, the study evaluated the representation of buffer strip as a vegetative barrier and as a riparian buffer using trapping efficiency and area ratio methods in SWAT. For the riparian buffer, the area ratio method tends to be more conservative, especially in nitrate loadings, while the trapping efficiency method generates more optimistic results. The differences between the two methods increase with buffer width. The two methods may not be comparable for the field-scale vegetative barrier simulation because of limitations in model spatial resolution. Landscape scenarios were developed to quantify water quality under (1) current land use, (2) partial land conversion to switchgrass, and (3) riparian buffer implementation. Results show that when low productivity land (15.2% of total watershed land area) is converted to grow switchgrass, suspended sediment, total nitrogen, total phosphorus, and nitrate loadings are reduced by 69.3%, 55.5%, 46.1%, and 13.4%, respectively, in the watershed surface streams. The reduction was less extensive when riparian buffer strips (30 m or 50 m) were applied to the stream network at 1.4% of total land area in the watershed. At the subbasin level, the degree of nutrient and suspended sediment reduction varies extensively, ranging from a few percent up to 55%. Results indicate that effective landscape design on current agricultural land can potentially bring marked improvements in water quality and soil erosion control while producing food and fuel feedstock in the South Fork Iowa River watershed. The concept can be integrated with other watershed management programs to improve sustainability of land, water, and the ecosystem.« less
NASA Astrophysics Data System (ADS)
Grazhdani, Dorina
2015-07-01
Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods—dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was €6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas.
Grazhdani, Dorina
2015-07-01
Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods--dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was
USDA-ARS?s Scientific Manuscript database
The USDA Southeast Watershed Research Laboratory is located in Tifton, Ga, and performs ongoing watershed research for the Tift County area, as well as surrounding counties. Current watershed delineations are based on 1972-1977, 7.5-minute USGS Quadrangle sheets, and require updating. Light Detectio...
Church, Stan E.; Von Guerard, Paul; Finger, Susan E.
2007-01-01
This publication comprises a Volume Contents of chapters (listed below) and a CD-ROM of data (contents shown in column at right). The Animas River watershed in southwest Colorado is one of many watersheds in the western United States where historical mining has left a legacy of acid mine drainage and elevated concentrations of potentially toxic trace elements in surface streams. U.S. Geological Survey scientists have completed a major assessment of the environmental effects of historical mining in the Animas River watershed focusing on the area upstream of Silverton, Colo.?the Mineral Creek, Cement Creek, and upper Animas River basins. The study demonstrated how the watershed approach can be used to assess and rank mining-affected sites for possible cleanup. The study was conducted in collaboration with State and Federal land-management agencies and regional stakeholders groups. This book is available for purchase at Information Services, U.S. Geological Survey (1-888-ASK-USGS).
NASA Astrophysics Data System (ADS)
Mosaad, Sayed
2017-10-01
This study demonstrates the importance of geomorphologic, geologic and hydrogeologic assessment as an efficient approach for water resources development in the Kharit watershed. Kharit is one of largest watersheds in the Eastern Desert that lacks water for agricultural and drinking purposes, for the nomadic communities. This study aims to identify and evaluate the geomorphologic, geologic and hydrogeologic conditions in the Kharit watershed relative to water resource development using remote sensing and GIS techniques. The results reveal that the watershed contains 15 sub-basins and morphometric analyses show high probability for flash floods. These hazards can be managed by constructing earth dikes and masonry dams to minimize damage from flash floods and allow recharge of water to shallow groundwater aquifers. The Quaternary deposits and the Nubian sandstone have moderate to high infiltration rates and are relatively well drained, facilitating surface runoff and deep percolation into the underlying units. The sediments cover 54% of the watershed area and have high potential for groundwater extraction.
NASA Astrophysics Data System (ADS)
Mukundan, Rajith; Pradhanang, Soni M.; Schneiderman, Elliot M.; Pierson, Donald C.; Anandhi, Aavudai; Zion, Mark S.; Matonse, Adão H.; Lounsbury, David G.; Steenhuis, Tammo S.
2013-02-01
High suspended sediment loads and the resulting turbidity can impact the use of surface waters for water supply and other designated uses. Changes in fluvial sediment loads influence material fluxes, aquatic geochemistry, water quality, channel morphology, and aquatic habitats. Therefore, quantifying spatial and temporal patterns in sediment loads is important both for understanding and predicting soil erosion and sediment transport processes as well as watershed-scale management of sediment and associated pollutants. A case study from the 891 km2 Cannonsville watershed, one of the major watersheds in the New York City water supply system is presented. The objective of this study was to apply Soil and Water Assessment Tool-Water Balance (SWAT-WB), a physically based semi-distributed model to identify suspended sediment generating source areas under current conditions and to simulate potential climate change impacts on soil erosion and suspended sediment yield in the study watershed for a set of future climate scenarios representative of the period 2081-2100. Future scenarios developed using nine global climate model (GCM) simulations indicate a sharp increase in the annual rates of soil erosion although a similar result in sediment yield at the watershed outlet was not evident. Future climate related changes in soil erosion and sediment yield appeared more significant in the winter due to a shift in the timing of snowmelt and also due to a decrease in the proportion of precipitation received as snow. Although an increase in future summer precipitation was predicted, soil erosion and sediment yield appeared to decrease owing to an increase in soil moisture deficit and a decrease in water yield due to increased evapotranspiration.
NASA Astrophysics Data System (ADS)
Kumar, Saurav; Godrej, Adil N.; Grizzard, Thomas J.
2016-09-01
Pre-development conditions are an easily understood state to which watershed nonpoint nutrient reduction targets may be referenced. Using the pre-development baseline, a "developed-excess" measure may be computed for changes due to anthropogenic development. Developed-excess is independent of many geographical, physical, and hydrological characteristics of the region and after normalization by area may be used for comparison among various sub-sets of the watershed, such as jurisdictions or land use types. We have demonstrated this method by computing pre-development nitrogen and phosphorus loads entering the Occoquan Reservoir from its tributary watershed in Northern Virginia. The pre-development loads in this study were computed using the calibrated water quality models for the period 2002-2007. Current forest land was used as a surrogate for pre-development land use conditions for the watershed and developed-excess was estimated for fluvial loads of Total Inorganic Nitrogen (TIN) and Orthophosphate-Phosphorus (OP) by subtracting simulated predevelopment loads from observed loads. It was observed that within the study period (2002-2007), the average annual developed-excess represented about 30% of the TIN and OP average annual loads exported to the reservoir. Comparison of the two disturbed land use types, urban and agricultural, showed that urban land uses exported significantly more excess nonpoint nutrient load per unit area than agricultural land uses.
Jujnovsky, Julieta; González-Martínez, Teresa Margarita; Cantoral-Uriza, Enrique Arturo; Almeida-Leñero, Lucia
2012-03-01
Studies from the ecosystem services perspective can provide a useful framework because they allow us to fully examine the benefits that humans obtain from socio-ecological systems. Mexico City, the second largest city in the world, has faced severe problems related to water shortages, which have worsened due to increasing population. Demand for space has forced changes in land cover, including covering areas that are essential for groundwater recharge. The city has 880 km(2) of forest areas that are crucial for the water supply. The Magdalena River Watershed was chosen as a model because it is a well-preserved zone within Mexico City and it provides water for the population. The general aim of this study was to assess the ecosystem service of the water supply in the Magdalena River Watershed by determining its water balance (SWAT model) and the number of beneficiaries of the ecosystem services. The results showed that the watershed provides 18.4 hm(3) of water per year. Baseflow was dominant, with a contribution of 85%, while surface runoff only accounted for 15%. The zone provides drinking water to 78,476 inhabitants and could supply 153,203 potential beneficiaries. This work provides an example for understanding how ecosystem processes determine the provision of ecosystem services and benefits to the population in a rural-urban watershed in Mexico City.
OPTIMIZING BMP PLACEMENT AT WATERSHED-SCALE USING SUSTAIN
Watershed and stormwater managers need modeling tools to evaluate alternative plans for environmental quality restoration and protection needs in urban and developing areas. A watershed-scale decision-support system, based on cost optimization, provides an essential tool to suppo...
U.S. EPA's Watershed Management Research Activities
Watershed and stormwater managers need modeling tools to evaluate alternative plans for environmental quality restoration and protection needs in urban and developing areas. A watershed-scale decision-support system, based on cost optimization, provides an essential tool to suppo...
Subdivision of Texas watersheds for hydrologic modeling.
DOT National Transportation Integrated Search
2009-06-01
The purpose of this report is to present a set of findings and examples for subdivision of watersheds for hydrologic modeling. Three approaches were used to examine the impact of watershed subdivision on modeled hydrologic response: (1) An equal-area...
IDENTIFICATION OF SEDIMENT SOURCE AREAS WITHIN A WATERSHED
Identification of sediment source areas is crucial for designing proper abatement strategies that reduce sediment and associated contaminant loading to receiving water downstream. In this study, two methodologies were developed to identify the source areas and their relative stre...
Clearwater Focus Watershed; Nez Perce Tribe, 2002-2003 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jones, Ira
2004-01-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division, approaches watershed restoration with a goal to protect, restore, and enhance a connected network of functioning habitat types capable of supporting all fish life stages. Its goal is also to re-establish normal patters of production, dispersal, and exchange of genetic information within the 1855 Treaty Area. The Nez Perce Tribe began watershed restoration projects within the Clearwater River Subbasin in 1996. Progress has been made in restoring the sub-basin by excluding cattle from critical riparian areas through fencing, stabilizing streambanks, decommissioning roads, and upgrading culverts. Coordination of these projectsmore » is critical to the success of the restoration of the sub-basin. Coordination includes: within department coordination, sub-basin assessment and planning, and treaty area coordination.« less
NASA Astrophysics Data System (ADS)
Lee, Ming-Hsi; Huang, Cong-Gi; Lin, Huan-Hsuan
2016-04-01
As a result of heavy rainfall, steep topography, young and weak geological formations, earthquakes, loose soils, slope land cultivation and other human disturbance, much area in Taiwan are prone to the occurrence of disastrous mass movements such as landslides and sediment disasters. During recent years, the extreme rainfall events brought huge amounts of rainfall and triggered severe changes in watershed environments. Typhoon Morakot in August 2009 caused severe landslides, debris flow, flooding and sediment disasters induced by record-break rainfall. The maximum rainfall of mountain area in Chiayi, Tainan, Kaohsiung and Pingtung County were over 2,900 mm. The study area is located at Nanhua reservoir watershed in southern Taiwan. The numerical model (HEC-RAS 4.1 and FLO-2D) will be used to simulate the sediment transport caused by landslide and the study will find out the separating location of erosion and deposition in the river, the danger area of riverbank, and the safety of the river terrace village under the return period of 50-year, 100-year and 200-year (such as Typhoon Morakot). The results of this study can provide for the disaster risk management of administrative decisions to lessen the impacts of natural hazards and may also be useful for time-space variation of sediment disasters caused by Climate Change.
Understanding of morphometric features for adequate water resource management in arid environments
NASA Astrophysics Data System (ADS)
Elhag, Mohamed; Galal, Hanaa K.; Alsubaie, Haneen
2017-08-01
Hydrological characteristics such as topographic parameters, drainage attributes, and land use/land cover patterns are essential to evaluate the water resource management of a watershed area. In the current study, delineation of a watershed and calculation of morphometric characteristics were undertaken using the ASTER global digital elevation model (GDEM). The drainage density of the basin was estimated to be very high, which indicates that the watershed possesses highly permeable soils and low to medium relief. The stream order of the area ranges from first to sixth order, showing a semi-dendritic and radial drainage pattern that indicates heterogeneity in textural characteristics, and it is influenced by structural characteristics in the study area. The bifurcation ratio (Rb) of the basin ranges from 2.0 to 4.42, and the mean bifurcation ratio is 3.84 in the entire study area, which signifies that the drainage pattern of the entire basin is controlled much more by the lithological and geological structure. The elongation ratio is 0.14, which indicates that the shape of the basin has a narrow and elongated shape. A land use/land cover map was generated by using a Landsat-8 image acquired on 10 August 2015 and classified to distinguish mainly the alluvial deposit from the mountainous rock.
Markose, Vipin Joseph; Jayappa, K S
2016-04-01
Most of the mountainous regions in tropical humid climatic zone experience severe soil loss due to natural factors. In the absence of measured data, modeling techniques play a crucial role for quantitative estimation of soil loss in such regions. The objective of this research work is to estimate soil loss and prioritize the sub-watersheds of Kali River basin using Revised Universal Soil Loss Equation (RUSLE) model. Various thematic layers of RUSLE factors such as rainfall erosivity (R), soil erodibility (K), topographic factor (LS), crop management factor (C), and support practice factor (P) have been prepared by using multiple spatial and non-spatial data sets. These layers are integrated in geographic information system (GIS) environment and estimated the soil loss. The results show that ∼42 % of the study area falls under low erosion risk and only 6.97 % area suffer from very high erosion risk. Based on the rate of soil loss, 165 sub-watersheds have been prioritized into four categories-very high, high, moderate, and low erosion risk. Anthropogenic activities such as deforestation, construction of dams, and rapid urbanization are the main reasons for high rate of soil loss in the study area. The soil erosion rate and prioritization maps help in implementation of a proper watershed management plan for the river basin.
Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo
2014-01-01
Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan watershed (from 1954 to 2010), and Yanhe watershed (from 1952 to 2010) in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P = 0.01) while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000–2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed. PMID:24955424
Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo
2014-01-01
Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan watershed (from 1954 to 2010), and Yanhe watershed (from 1952 to 2010) in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P = 0.01) while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000-2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed.
South Platte Watershed from the Headwaters to the Denver Metropolitan Area (Colorado) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating
Üçler, N; Engin, G Onkal; Köçken, H G; Öncel, M S
2015-05-01
In this study, game theory and fuzzy programming approaches were used to balance economic and environmental impacts in the Namazgah reservoir, Turkey. The main goals identified were to maximize economic benefits of land use and to protect water quality of reservoir and land resources. Total phosphorous load (kg ha(-1) year(-1)) and economic income (USD ha(-1) year(-1)) from land use were determined as environmental value and economic value, respectively. The surface area of existing land use types, which are grouped under 10 headings according to the investigations on the watershed area, and the constraint values for the watershed were calculated using aerial photos, master plans, and basin slope map. The results of fuzzy programming approach were found to be very close to the results of the game theory model. It was concluded that the amount of fertilizer used in the current situation presents a danger to the reservoir and, therefore, unnecessary fertilizer use should be prevented. Additionally, nuts, fruit, and vegetable cultivation, instead of wheat and corn cultivation, was found to be more suitable due to their high economic income and low total phosphorus (TP) load. Apart from agricultural activities, livestock farming should also be considered in the area as a second source of income. It is believed that the results obtained in this study will help decision makers to identify possible problems of the watershed.
NASA Astrophysics Data System (ADS)
Chabaux, François; Viville, Daniel; Pierret, Marie-Claire; Stille, Peter; Lerouge, Catherine; Wyns, Robert; Dezayes, Chrystel; Labasque, Thierry; Aquilina, Luc; Ranchoux, Coralie; Négrel, Philippe
2017-04-01
The characterization of the critical zone along depth profiles remains a major scientific issue for understanding and modelling the response of continental surfaces to climatic, tectonic and anthropogenic forcings. Besides characterization it requires the modelling of the water circulations within the substratum of the critical zone. A series of boreholes drilled along the north and the south slopes of the Strengbach watershed makes it possible to characterize the critical zone to depths of ≈100 to 150 m within this critical zone observatory. In this study we attempt to combine mineralogical and petrological observations of the cores recovered through the drilling with chemical data of waters collected in each of these wells and hydro-geophysical data in order to characterize processes of water-rock interactions, visualize the water arrivals within the boreholes and bring new information on the deep water circulations within the watershed. Mineralogical, petrological and hydrogeophysical data suggest that deepwater circulation in the watershed likely occurs along fractures, concentrated in relatively narrow areas, several centimeters wide, interspersed with areas where the granite is much less fractured. This points to the occurrence of deep waters circulating in a network of more or less independent conduits, which could extend over several tens to hundreds of meters deep. The hydrochemical data from the boreholes, show contrasting characteristics for surface waters collected at 10 to 15 m depth and the deeper waters collected between 50 to 80m depth; the surface waters are very similar to those of the spring waters collected in the watershed (Pierret et al., 2014), and the deeper waters collected between 50 to 80m depth. The residence times of the circulating waters are also very variable, with ages of up to a few months for surface and subsurface waters and ages exceeding several decades for the deep waters. These differences suggest that the subsurface circulation systems are quite different from the deeper circulation ones. They also point to the importance to focus future studies on deep-water circulations in order to properly characterize the functioning of the critical zone in watersheds, especially in mountainous areas, such as the Strengbach watershed.
Reddy, D.R.
1971-01-01
IntroductionHistory of Small Watershed Projects in TexasThe U.S. Soil Conservation Service is actively engaged in the installation of flood and soil erosion reducing measures in Texas under the authority of the "Flood Control Act of 1936 and 1944" and "Watershed Protection and Flood Prevention Act" (Public Law 566), as amended. The Soil Conservation Service has found a total of approximately 3,500 floodwater-retarding structures to be physically and economically feasible in Texas. As of September 30, 1970, 1,439 of these structures had been built.This watershed-development program will have varying but important effects on the surface and ground-water resources of river basins, especially where a large number of the floodwater-retarding structures are built. Basic hydrologic data under natural and developed conditions are needed to appraise the effects of the structures on the yield and mode of occurrence of runoff.Hydrologic investigations of these small watersheds were begun by the Geological Survey in 1951 and are now being made in 12 study areas (fig. 1). These investigations are being made in cooperation with the Texas Water Development Board, the Soil Conservation Service, the San Antonio River Authority, the city of Dallas, and the Tarrant County Water Control and Improvement District No. 1. The 12 study areas were chosen to sample watershed having different rainfall, topography, geology, and soils. In five of the study areas, (North, Little Elm, Mukewater, little Pond-North Elm, and Pin Oak Creeks), streamflow and rainfall records were collected prior to construction of the floodwater-retarding structures, thus affording the opportunity for analyses of the conditions "before and after" development. A summary of the development of the floodwater-retarding structures in each study areas of September 30, 1970, is shown in table 1.Objectives of the Texas Small Watersheds ProjectThe purpose of these investigations is to collect sufficient data to meeting the following objectives:To determine the net effect of floodwater-retarding structures on the regimen of streamflow at downstream points.To determine the effectiveness of the structures as ground-water recharge facilities.To determine the effect of the structures on the sediment yield at downstream points.To develop relationships between maximum rates and/or volumes of runoff with rainfall in small natural watersheds.To develop a stream-system model for basins with floodwater-retarding structures.To determine the minimum instrumentation necessary for estimating the flood hydrographs below a system of structures, as needed for downstream water-management operation.Purpose and Scope of this Basic-Data ReportThis report, which is the tenth in a series of basic-data reports published annually for the Escondido Creek study area, contains the rainfall, runoff, and storage data collected during the 1970 water year for the 72.4-square-mile area above the stream-gaging station Escondido Creek at Kenedy, Texas. The location of floodwater-retarding structures and hydrologic-instrument installations in the Escondido Creek study area are shown on figure 2.This investigation is scheduled to continue through a period of both above- and below-normal precipitation to define the various factors used in the analyses of rainfall-runoff relationship.To facilitate the publication and distribution of this report at the earliest feasible time, certain material contained herein does not conform to the formal publication standards of the U.S. Geological Survey.
Effects of mountain resort development - a case study in Vermont USA
NASA Astrophysics Data System (ADS)
Shanley, J.; Wemple, B.
2012-04-01
The mountainous landscape of northern New England, USA, faces intense development pressure from recreational and tourism use. In 2000 we began a paired-watershed study in northern Vermont to examine the effects of alpine resort development on stream flow and water quality. To our knowledge this is the only gaged watershed study at a mountain resort. The adjacent paired watersheds have similar topography, relief, geology and forest type, and differ primarily in land use. Ranch Brook watershed (9.6 km2) is the undeveloped, nearly 100% forested control basin. West Branch watershed (11.7 km2) is the developed basin, encompassing a pre-existing alpine ski resort and state highway, with approximately 17% of the basin occupied by ski trails and impervious surfaces. Measurements during 2000-2003 showed suspended sediment yield was >2.5 times greater and concentrations of nitrate and chloride were significantly elevated at West Branch. From 2004 through 2007 the resort expanded with more ski trails, roads, parking areas, and vacation home development and now has 24% cleared land, with storm sewers draining lower developed areas of the alpine watershed. For the 11-year period of study, water yield in the developed basin exceeded that in the control by an average of nearly 21%. The higher runoff at West Branch occurred primarily as result of higher sustained base flow, driven by a more prolonged snowmelt period, and greater runoff during small events. The annual flow differential had a strong positive correlation to maximum snow water equivalent, suggesting that differences in snow accumulation may explain the flow differential. We are investigating whether these differences are a direct consequence of management activities and resulting vegetation shifts and land clearing on snow capture. Several of the highest peak flows in both watersheds have occurred in the last 2 years of the 11-yr study. Our analysis is aimed at determining whether absolute peak flows have increased disproportionately at West Branch relative to the overall flow differential. As actual pre- and post-expansion flows differ markedly from design projections, our study also bears out the need for science-based management decisions.
Evidence for a regime shift in nitrogen export from a forested watershed
J. R. Webster; Jennifer Knoepp; Wayne Swank; Chelcy Miniat
2016-01-01
In this study, we document a functional regime shift in stream inorganic nitrogen (N) processing indicated by a major change in N export from a forested watershed. Evidence from 36Â years of data following experimental clearcut logging at Coweeta Hydrologic Laboratory, NC, suggests that forest disturbance in this area can cause elevation of dissolved inorganic...
Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng
2017-03-03
In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world.
Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng
2017-01-01
In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world. PMID:28273834
Relation of biomass to basal area and site index on an Appalachian watershed
Harry V., Jr. Wiant; Robert Knight; John E. Baumgras
1984-01-01
The biomass of 50-year-old cove hardwood and upland oak stands on an Appalachian watershed was more strongly related to basal area than to site index. Equations are presented for predicting the green and dry weight per acre of biomass components with basal area as the independent variable.
Hydrologic data from urban watersheds in the Tampa Bay area, Florida
Lopez, Miguel A.; Michaelis, D.M.
1979-01-01
Hydrologic data are being collected in 10 urbanized watersheds located in the Tampa Bay area, Florida. The gaged watersheds have impervious areas that range from 19 percent for a residential watershed in north Tampa to nearly 100 percent for a downtown Tampa watershed. Land-use types, including roads, residential, commercial, industrial, institutional, recreational , and open space, have been determined for each watershed. Rainfall and storm runoff data collected since 1971 for one site and since 1975 for six other sites through September 1976, have been processed. These data are recorded at 5-minute intervals and are stored in the U. S. Geological Survey WATSTORE unit values file. Daily rainfall at 12 sites and daily pan evaporation at one site have been stored in the WATSTORE daily values file. Chemical and biological analyses of storm runoff for six sites, base flow for seven sites, and analyses of bottom material for seven sites are also stored in the WATSTORE water-quality files. Rainfall and storm runoff for selected storms, daily rainfall, and daily pan-evaporation data are summarized in this report. Water-quality analyses of all water-quality samples also are listed. (Woodard-USGS).
NASA Astrophysics Data System (ADS)
Yeo, I. Y.
2016-12-01
Wetlands are valuable landscape features that provide important ecosystem functions and services. The ecosystem processes in wetlands are highly dependent on the hydrology. However, hydroperiod (i.e., change dynamics in inundation extent) is highly variable spatially and temporarily, and extremely difficult to predict owing to the complexity in hydrological processes within wetlands and its interaction with surrounding areas. This study reports the challenges and progress in assessing the catchment scale benefits of wetlands to regulate hydrological regime and water quality improvement in agricultural watershed. A process-based watershed model, Soil and Water Assessment Tool (SWAT) was improved to simulate the cumulative impacts of wetlands on downstream. Newly developed remote sensing products from LiDAR intensity and time series Landsat records, which show the inter-annual changes in fraction inundation, were utilized to describe the change status of inundated areas within forested wetlands, develop spatially varying wetland parameters, and evaluate the predicted inundated areas at the landscape level. We outline the challenges on developing the time series inundation mapping products at a high spatial and temporal resolution and reconciling the catchment scale model with the moderate remote sensing products. We then highlight the importance of integrating spatialized information to model calibration and evaluation to address the issues of equi-finality and prediction uncertainty. This integrated approach was applied to the upper region of Choptank River Watershed, the agricultural watershed in the Coastal Plain of Chesapeake Bay Watershed (in US). In the Mid- Atlantic US, the provision of pollution regulation services provided by wetlands has been emphasized due to declining water quality within the Chesapeake Bay and watersheds, and the preservation and restoration of wetlands has become the top priority to manage nonpoint source water pollution.
Mutch, L.S.; Parsons, D.J.
1998-01-01
Pre-and post-burn tree mortality rates, size structure, basal area, and ingrowth were determined for four 1.0 ha mixed conifer forest stands in the Log Creek and Tharp's Creek watersheds of Sequoia National Park. Mean annual mortality between 1986 and 1990 was 0.8% for both watersheds. In the fall of 1990, the Tharp's Creek watershed was treated with a prescribed burn. Between 1991 and 1995, mean annual mortality was 1.4% in the unburned Log Creek watershed and 17.2% in the burned Tharp's Creek watershed. A drought from 1987 to 1992 likely contributed to the mortality increase in the Log Creek watershed. The high mortality in the Tharp's Creek watershed was primarily related to crown scorch from the 1990 fire and was modeled with logistic regression for white fir (Abies concolor [Gord. and Glend.]) and sugar pine (Pinus lambertiana [Dougl.]). From 1989 to 1994, basal area declined an average of 5% per year in the burned Tharp's Creek watershed, compared to average annual increases of less than 1% per year in the unburned Log Creek watershed and in the Tharp's watershed prior to burning. Post-burn size structure was dramatically changed in the Tharp's Creek stands: 75% of trees ???50 cm and 25% of trees >50 cm were killed by the fire.
Norman, Laura M.; Niraula, Rewati
2016-01-01
The objective of this study was to evaluate the effect of check dam infrastructure on soil and water conservation at the catchment scale using the Soil and Water Assessment Tool (SWAT). This paired watershed study includes a watershed treated with over 2000 check dams and a Control watershed which has none, in the West Turkey Creek watershed, Southeast Arizona, USA. SWAT was calibrated for streamflow using discharge documented during the summer of 2013 at the Control site. Model results depict the necessity to eliminate lateral flow from SWAT models of aridland environments, the urgency to standardize geospatial soils data, and the care for which modelers must document altering parameters when presenting findings. Performance was assessed using the percent bias (PBIAS), with values of ±2.34%. The calibrated model was then used to examine the impacts of check dams at the Treated watershed. Approximately 630 tons of sediment is estimated to be stored behind check dams in the Treated watershed over the 3-year simulation, increasing water quality for fish habitat. A minimum precipitation event of 15 mm was necessary to instigate the detachment of soil, sediments, or rock from the study area, which occurred 2% of the time. The resulting watershed model is useful as a predictive framework and decision-support tool to consider long-term impacts of restoration and potential for future restoration.
McKenzie River Focus Watershed Coordination: Year-End Report 2000.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thrailkil, Jim
2000-01-01
This report summarizes accomplishments of the McKenzie River Focus Watershed Council (MWC) in the areas of coordination and administration during Fiscal Year 2000. Coordination and administration consist of prioritization and planning for projects; project management and implementation; procurement of funding for long-term support of the Council; and watershed education/outreach program for residents and local schools. Key accomplishments in the area of project planning include coordinating: monthly Council and executive committee meetings; staffing the Upper Willamette Spring Chinook Working Group; staffing the water quality technical committee; and guiding education and stewardship projects. Key accomplishments in the area of project management includemore » the completion of the McKenzie-Willamette Confluence Assessment; securing funds for project planning in the confluence area; near completion of the BPA funded McKenzie sub-basin assessment; development of a framework for a McKenzie Watershed Conservation Strategy; an evaluation of Council's monitoring programs - ambient water quality, storm-event water quality, Tier III water quality, and macroinvertebrate monitoring. The Council, in cooperation with the McKenzie River Cooperative, completed habitat enhancements in the Gate Creek and Deer Creek sub-watersheds. This partnership recently submitted Bring Back the Natives grant for initiation of projects in other McKenzie tributaries. The Council will also be working with a local business to develop a river-side riparian enhancement and native landscaping project on the lodge grounds. This will serve as a demonstration project for blending fish and wildlife habitat concerns with maintaining grounds for business opportunities. Accomplishments in the area of procurement of funding included developing the FY2000 Scope of Work and budget for approval by the Council and BPA; providing quarterly budget and work program progress reports to the Council; and securing additional funding from Council partner organizations and foundations. Highlights in the area of watershed education/outreach include the MWC's lead role in convening the Watershed Education Network for teachers as part of its educational mission; production of newsletters and brochures; and coordination of media coverage of watershed-related issues.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Confederated Tribes of the Umatilla Indian Reservation Wildlife Program
The Confederated Tribes of the Umatilla Indian Reservation (CTUIR) propose to protect, enhance, and mitigate wildlife and wildlife habitat and watershed resources in the Iskuulpa Watershed. The Iskuulpa Watershed Project was approved as a Columbia River Basin Wildlife Fish and Mitigation Project by the Bonneville Power Administration (BPA) and Northwest Power Planning Council (NWPPC) in 1998. Iskuulpa will contribute towards meeting BPA's obligation to compensate for wildlife habitat losses resulting from the construction of the John Day and McNary Hydroelectric facilities on the Columbia River. By funding the enhancement and operation and maintenance of the Iskuulpa Watershed, BPA will receivemore » credit towards their mitigation debt. The purpose of the Iskuulpa Watershed management plan update is to provide programmatic and site-specific standards and guidelines on how the Iskuulpa Watershed will be managed over the next three years. This plan provides overall guidance on both short and long term activities that will move the area towards the goals, objectives, and desired future conditions for the planning area. The plan will incorporate managed and protected wildlife and wildlife habitat, including operations and maintenance, enhancements, and access and travel management.« less
Baker, Ronald J.; Wieben, Christine M.; Lathrop, Richard G.; Nicholson, Robert S.
2014-01-01
Concentrations, loads, and yields of nutrients (total nitrogen and total phosphorus) were calculated for the Barnegat Bay-Little Egg Harbor (BB-LEH) watershed for 1989–2011 at annual and seasonal (growing and nongrowing) time scales. Concentrations, loads, and yields were calculated at three spatial scales: for each of the 81 subbasins specified by 14-digit hydrologic unit codes (HUC-14s); for each of the three BB-LEH watershed segments, which coincide with segmentation of the BB-LEH estuary; and for the entire BB-LEH watershed. Base-flow and runoff values were calculated separately and were combined to provide total values. Available surface-water-quality data for all streams in the BB-LEH watershed for 1980–2011 were compiled from existing datasets and quality assured. Precipitation and streamflow data were used to distinguish between water-quality samples that were collected during base-flow conditions and those that were collected during runoff conditions. Base-flow separation of hydrographs of six streams in the BB-LEH watershed indicated that base flow accounts for about 72 to 94 percent of total flow in streams in the watershed. Base-flow mean concentrations (BMCs) of total nitrogen (TN) and total phosphorus (TP) for each HUC-14 subbasin were calculated from relations between land use and measured base-flow concentrations. These relations were developed from multiple linear regression models determined from water-quality data collected at sampling stations in the BB-LEH watershed under base-flow conditions and land-use percentages in the contributing drainage basins. The total watershed base-flow volume was estimated for each year and season from continuous streamflow records for 1989–2011 and relations between precipitation and streamflow during base-flow conditions. For each year and season, the base-flow load and yield were then calculated for each HUC-14 subbasin from the BMCs, total base-flow volume, and drainage area. The watershed-loading application PLOAD was used to calculate runoff concentrations, loads, and yields of TN and TP at the HUC-14 scale. Flow-weighted event-mean concentrations (EMCs) for runoff were developed for each major land-use type in the watershed using storm sampling data from four streams in the BB-LEH watershed and three streams outside the watershed. The EMCs were developed separately for the growing and nongrowing seasons, and were typically greater during the growing season. The EMCs, along with annual and seasonal precipitation amounts and percent imperviousness associated with land-use types, were used as inputs to PLOAD to calculate annual and seasonal runoff concentrations, loads, and yields at the HUC-14 scale. Over the period of study (1989–2011), total surface-water loads (base flow plus runoff) for the entire BB-LEH watershed for TN ranged from about 455,000 kilograms (kg) as N (1995) to 857,000 kg as N (2010). For TP, total loads for the watershed ranged from about 17,000 (1995) to 32,000 kg as P (2010). On average, the north segment accounted for about 66 percent of the annual TN load and 63 percent of the annual TP load, and the central and south segments each accounted for less than 20 percent of the nutrient loads. Loads and yields were strongly associated with precipitation patterns, ensuing hydrologic conditions, and land use. HUC-14 subbasins with the highest yields of nutrients are concentrated in the northern part of the watershed, and have the highest percentages of urban or agricultural land use. Subbasins with the lowest TN and TP yields are dominated by forest cover. Percentages of turf (lawn) cover and nonturf cover were estimated for the watershed. Of the developed land in the watershed, nearly one quarter (24.9 percent) was mapped as turf cover. Because there is a strong relation between percent turf and percent developed land, percent turf in the watershed typically increases with percent development, and the amount of development can be considered a reasonable predictor of the amount of turf cover in the watershed. In the BB-LEH watershed, calculated concentrations of TN and TP were greater for developed–turf areas than for developed–nonturf areas, which, in turn, were greater than those for undeveloped areas.
NASA Astrophysics Data System (ADS)
Teisserenc, Roman; Lucotte, Marc; Houel, Stéphane; Carreau, Jean
2010-11-01
Terrigenous organic matter (TOM) transfer from a watershed to a lake plays a key role in contaminants fate and greenhouse gazes emission in these aquatic ecosystems. In this study, we linked physiographic and vegetation characteristics of a watershed with TOM nature deposited in lake sediments. TOM was characterized using lignin biomarkers as indicators of TOM sources and state of degradation. Geographical information system (GIS) also allowed us to integrate and describe the landscape morpho-edaphic characteristics of a defined drainage basin. Combining these tools we found a significant and positive relationship ( R2 = 0.65, p < 0.002) between mean slope of the watershed and the terrigenous fraction estimated by Λ8 in recent sediments. The mean slope also correlated with the composition of TOM in recent sediments as P/(V + S) and 3,5Bd/V ratios significantly decreased with the steepness of the watersheds ( R2 = 0.57, p < 0.021 and R2 = 0.71, p < 0.004, respectively). More precisely, areas with slopes comprised between 4° and 10° have a major influence on TOM inputs to lakes. The vegetation composition of each watershed influenced the composition of recent sediments of the sampled lakes. The increasing presence of angiosperm trees in the watershed influenced the export of TOM to the lake as Λ8 increased significantly with the presence of this type of vegetation ( R2 = 0.44, p < 0.019). A similar relationship was also observed with S/V ratios, an indicator of angiosperm sources for TOM. The type of vegetation also greatly influenced the degradation state of OM. In this study, we were able to determine that low-sloped areas (0-2°) act as buffer zones for lignin inputs and by extension for TOM loading to sediments. The relative contribution of TOM from the soil organic horizons also increased in steeper watersheds. This study has significant implications in our understanding of the fate of TOM in lacustrine ecosystems.
Drainage networks after wildfire
Kinner, D.A.; Moody, J.A.
2005-01-01
Predicting runoff and erosion from watersheds burned by wildfires requires an understanding of the three-dimensional structure of both hillslope and channel drainage networks. We investigate the small-and large-scale structures of drainage networks using field studies and computer analysis of 30-m digital elevation model. Topologic variables were derived from a composite 30-m DEM, which included 14 order 6 watersheds within the Pikes Peak batholith. Both topologic and hydraulic variables were measured in the field in two smaller burned watersheds (3.7 and 7.0 hectares) located within one of the order 6 watersheds burned by the 1996 Buffalo Creek Fire in Central Colorado. Horton ratios of topologic variables (stream number, drainage area, stream length, and stream slope) for small-scale and large-scale watersheds are shown to scale geometrically with stream order (i.e., to be scale invariant). However, the ratios derived for the large-scale drainage networks could not be used to predict the rill and gully drainage network structure. Hydraulic variables (width, depth, cross-sectional area, and bed roughness) for small-scale drainage networks were found to be scale invariant across 3 to 4 stream orders. The relation between hydraulic radius and cross-sectional area is similar for rills and gullies, suggesting that their geometry can be treated similarly in hydraulic modeling. Additionally, the rills and gullies have relatively small width-to-depth ratios, implying sidewall friction may be important to the erosion and evolutionary process relative to main stem channels.
Regional prioritisation of flood risk in mountainous areas
NASA Astrophysics Data System (ADS)
Rogelis, M. C.; Werner, M.; Obregón, N.; Wright, G.
2015-07-01
A regional analysis of flood risk was carried out in the mountainous area surrounding the city of Bogotá (Colombia). Vulnerability at regional level was assessed on the basis of a principal component analysis carried out with variables recognised in literature to contribute to vulnerability; using watersheds as the unit of analysis. The area exposed was obtained from a simplified flood analysis at regional level to provide a mask where vulnerability variables were extracted. The vulnerability indicator obtained from the principal component analysis was combined with an existing susceptibility indicator, thus providing an index that allows the watersheds to be prioritised in support of flood risk management at regional level. Results show that the components of vulnerability can be expressed in terms of four constituent indicators; socio-economic fragility, which is composed of demography and lack of well-being; lack of resilience, which is composed of education, preparedness and response capacity, rescue capacity, social cohesion and participation; and physical exposure is composed of exposed infrastructure and exposed population. A sensitivity analysis shows that the classification of vulnerability is robust for watersheds with low and high values of the vulnerability indicator, while some watersheds with intermediate values of the indicator are sensitive to shifting between medium and high vulnerability. The complex interaction between vulnerability and hazard is evidenced in the case study. Environmental degradation in vulnerable watersheds shows the influence that vulnerability exerts on hazard and vice versa, thus establishing a cycle that builds up risk conditions.
An Analysis of Microbial Pollution in the Sinclair-Dyes Inlet Watershed
DOE Office of Scientific and Technical Information (OSTI.GOV)
May, Christopher W.; Cullinan, Valerie I.
2005-09-21
This assessment of fecal coliform sources and pathways in Sinclair and Dyes Inlets is part of the Project ENVironmental InVESTment (ENVVEST) being conducted by the Navy's Puget Sound Naval Shipyard and Intermediate Maintenance Facility in cooperation with the US Environmental Protection Agency, Washington State Department of Ecology, the Suquamish Tribe, Kitsap County, the City of Bremerton, the City of Port Orchard, and other local stakeholders. The goal of this study was to identify microbial pollution problems within the Sinclair-Dyes Inlet watershed and to provide a comprehensive assessment of fecal coliform (FC) contamination from all identifiable sources in the watershed. Thismore » study quantifies levels of contamination and estimated loadings from known sources within the watersheds and describes pollutant transport mechanisms found in the study area. In addition, the effectiveness of pollution prevention and mitigation measures currently in place within the Sinclair-Dyes Inlet watershed are discussed. This comprehensive study relies on historical data collected by several cooperating agencies, in addition to data collected during the study period from spring 2001 through summer 2005. This report is intended to provide the technical information needed to continue current water quality cleanup efforts and to help implement future efforts.« less
Effect of historic land cover change on runoff curve number estimation in Iowa
Wehmeyer, Loren L.; Weirich, Frank H.
2010-01-01
Within three decades of European-descended settlers arriving in Iowa, much of the land cover across the state was transformed from prairie and forest to farmland, patches of forest, and urbanized areas. Between 1832 and 1859, the General Land Office surveyed the state of Iowa to aid in the disbursement of land. In 1875, an illustrated atlas of the State of Iowa was published. Using these two data resources for classifying land cover, the hydrologic impact of the land cover change resulting from the first three decades of settlement is presented in terms of the effect on the area-weighted average curve number, a term commonly used to predict runoff from rainstorms. In the four watersheds studied, the area-weighted average curve number increased by a mean of 16.4 from 61.4 to 77.8 with the greatest magnitude of change occurring in the two western Iowa watersheds as opposed to the two more heavily forested eastern Iowa watersheds.
Impact of land cover and land use change on runoff characteristics.
Sajikumar, N; Remya, R S
2015-09-15
Change in Land Cover and Land Use (LCLU) influences the runoff characteristics of a drainage basin to a large extent, which in turn, affects the surface and groundwater availability of the area, and hence leads to further change in LCLU. This forms a vicious circle. Hence it becomes essential to assess the effect of change in LCLU on the runoff characteristics of a region in general and of small watershed levels (sub-basin levels) in particular. Such an analysis can effectively be carried out by using watershed simulation models with integrated GIS frame work. SWAT (Soil and Water Analysis Tool) model, being one of the versatile watershed simulation models, is found to be suitable for this purpose as many GIS integration modules are available for this model (e.g. ArcSWAT, MWSWAT). Watershed simulation using SWAT requires the land use and land cover data, soil data and many other features. With the availability of repository of satellite imageries, both from Indian and foreign sources, it becomes possible to use the concurrent local land use and land cover data, thereby enabling more accurate modelling of small watersheds. Such availability will also enable us to assess the effect of LCLU on runoff characteristics and their reverse impact. The current study assesses the effect of land use and land cover on the runoff characteristics of two watersheds in Kerala, India. It also assesses how the change in land use and land cover in the last few decades affected the runoff characteristics of these watersheds. It is seen that the reduction in the forest area amounts to 60% and 32% in the analysed watersheds. However, the changes in the surface runoff for these watersheds are not comparable with the changes in the forest area but are within 20%. Similarly the maximum (peak) value of runoff has increased by an amount of 15% only. The lesser (aforementioned) effect than expected might be due to the fact that forest has been converted to agricultural purpose with major portion as plantations which have comparatively similar characteristics of the forest except for evapo-transpiration. The double sided action (increase in evapo-transpiration owing to species like rubber and increase percolation due to its plantation method by using terracing) might be the reason for relatively smaller effect of the land use change, not commensurate with the changes in the forest area amounting to 60% and 32% for Manali and Kurumali watersheds respectively. Water harvesting methods like rain harvesting ditches can be made mandatory where species with high evapo-transpiration are grown. This action shall enhance the groundwater percolation and shall counter act the effect due to high evapo-transpiration. Copyright © 2014 Elsevier Ltd. All rights reserved.
Development of a Watershed Boundary Dataset for Mississippi
Van Wilson, K.; Clair, Michael G.; Turnipseed, D. Phil; Rebich, Richard A.
2009-01-01
The U.S. Geological Survey, in cooperation with the Mississippi Department of Environmental Quality, U.S. Department of Agriculture-Natural Resources Conservation Service, Mississippi Department of Transportation, U.S. Department of Agriculture-Forest Service, and the Mississippi Automated Resource Information System, developed a 1:24,000-scale Watershed Boundary Dataset for Mississippi including watershed and subwatershed boundaries, codes, names, and drainage areas. The Watershed Boundary Dataset for Mississippi provides a standard geographical framework for water-resources and selected land-resources planning. The original 8-digit subbasins (hydrologic unit codes) were further subdivided into 10-digit watersheds and 12-digit subwatersheds - the exceptions are the Lower Mississippi River Alluvial Plain (known locally as the Delta) and the Mississippi River inside levees, which were only subdivided into 10-digit watersheds. Also, large water bodies in the Mississippi Sound along the coast were not delineated as small as a typical 12-digit subwatershed. All of the data - including watershed and subwatershed boundaries, hydrologic unit codes and names, and drainage-area data - are stored in a Geographic Information System database.
NASA Astrophysics Data System (ADS)
Sherwood, M. N.; O'Connor, M.; Pennington, R.
2007-12-01
Erosion and sedimentation have been identified as processes significantly affecting water quality in northern California Coast Range watersheds. These watersheds, including the Gualala River watershed in northwestern Sonoma County, have been designated as having water quality impaired by sediment under provisions of the Clean Water Act Section 303(d). A study was performed to estimate potential increases in erosion rates resulting from proposed vineyard development of ridge top forestland in the Gualala River watershed. The study area has an extensive history of logging, with substantial ground disturbance from tractors. The study area is characterized by flat ridge tops with steeply incised drainages shaped by debris slides, rock slides and earth flows. Jurassic age sedimentary and meta-sedimentary rocks of the coastal and central belt Franciscan formation comprise the underlying bedrock. Channel head development and advancement has long been understood to play a key role in sediment delivery and is possibly the most sensitive to changes in the external factors such as changes in climate or land use (Dietrich and Dunne 1993). Quantifying the amount of sediment contributed by potential channel head incision and/or initiation is an objective of environmental analysis for the project. Field surveys were performed during the field seasons of 2005 and 2006 to acquire measurements of channel head locations and slope, channel dimensions and substrate associated with the proposed development sites. Analysis of this field data, including the use of ArcGIS, allowed us to examine the local relationships between variables that influence channel initiation. Variables considered include drainage area, slope, soil type, geology and vegetation. An initial analysis of a selection of area-slope data failed to produce an inverse area-slope relationship as has been found in previous studies by Montgomery and Dietrich (1988). A more complete evaluation of the entire data set is presented here.
Relationship between land use and water quality in Pesanggrahan River
NASA Astrophysics Data System (ADS)
Effendi, Hefni; Muslimah, Sri; Ayu Permatasari, Prita
2018-05-01
Pesanggrahan River watershed has several activities such as residential and commercial area in its catchment area. The purpose of this study was to analyse water quality related to spatial land use in Pesanggrahan River using GIS Analysis. River water quality in some locations, did not meet water quality standard of class III. From pollution load estimation it was revealed that segment 2 (Bogor City) has the highest BOD, COD, and TSS of 15,043 kg/day, 25,619 kg/day, and 18,104 kg/day respectively. On the other hand, the most developed area in Pesanggrahan Watershed is located in segment 7 (24.5%). Hence, it can be concluded that although an area has a fairly small developed area, high urban activity can cause high BOD, COD, and TSS.
Development of a socio-ecological environmental justice model for watershed-based management
NASA Astrophysics Data System (ADS)
Sanchez, Georgina M.; Nejadhashemi, A. Pouyan; Zhang, Zhen; Woznicki, Sean A.; Habron, Geoffrey; Marquart-Pyatt, Sandra; Shortridge, Ashton
2014-10-01
The dynamics and relationships between society and nature are complex and difficult to predict. Anthropogenic activities affect the ecological integrity of our natural resources, specifically our streams. Further, it is well-established that the costs of these activities are born unequally by different human communities. This study considered the utility of integrating stream health metrics, based on stream health indicators, with socio-economic measures of communities, to better characterize these effects. This study used a spatial multi-factor model and bivariate mapping to produce a novel assessment for watershed management, identification of vulnerable areas, and allocation of resources. The study area is the Saginaw River watershed located in Michigan. In-stream hydrological and water quality data were used to predict fish and macroinvertebrate measures of stream health. These measures include the Index of Biological Integrity (IBI), Hilsenhoff Biotic Index (HBI), Family IBI, and total number of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa. Stream health indicators were then compared to spatially coincident socio-economic data, obtained from the United States Census Bureau (2010), including race, income, education, housing, and population size. Statistical analysis including spatial regression and cluster analysis were used to examine the correlation between vulnerable human populations and environmental conditions. Overall, limited correlation was observed between the socio-economic data and ecological measures of stream health, with the highest being a negative correlation of 0.18 between HBI and the social parameter household size. Clustering was observed in the datasets with urban areas representing a second order clustering effect over the watershed. Regions with the worst stream health and most vulnerable social populations were most commonly located nearby or down-stream to highly populated areas and agricultural lands.
NASA Astrophysics Data System (ADS)
Singh, Ramesh; Garg, Kaushal K.; Wani, Suhas P.; Tewari, R. K.; Dhyani, S. K.
2014-02-01
Bundelkhand region of Central India is a hot spot of water scarcity, land degradation, poverty and poor socio-economic status. Impacts of integrated watershed development (IWD) interventions on water balance and different ecosystem services are analyzed in one of the selected watershed of 850 ha in Bundelkhand region. Improved soil, water and crop management interventions in Garhkundar-Dabar (GKD) watershed of Bundelkhand region in India enhanced ET to 64% as compared to 58% in untreated (control) watershed receiving 815 mm annual average rainfall. Reduced storm flow (21% vs. 34%) along with increased base flow (4.5% vs. 1.2%) and groundwater recharge (11% vs. 7%) of total rainfall received were recorded in treated watershed as compared to untreated control watershed. Economic Water productivity and total income increased from 2.5 to 5.0 INR m-3 and 11,500 to 27,500 INR ha-1 yr-1 after implementing integrated watershed development interventions in GKD watershed, respectively. Moreover IWD interventions helped in reducing soil loss more than 50% compared to control watershed. The results demonstrated that integrated watershed management practices addressed issues of poverty in GKD watershed. Benefit to cost ratio of project interventions was found three and pay back period within four years suggest economic feasibility to scale-up IWD interventions in Bundelkhend region. Scaling-up of integrated watershed management in drought prone rainfed areas with enabling policy and institutional support is expected to promote equity and livelihood along with strengthening various ecosystem services, however, region-specific analysis is needed to assess trade-offs for downstream areas along with onsite impact.
NASA Astrophysics Data System (ADS)
Pramod Krishna, Akhouri
A watershed in Chhotanagpur plateau region was investigated utilizing space data from Indian Remote Sensing (IRS) Satellite towards spatial and temporal soil erosion process study. Geomorphologically, this plateau region is an undulating pediplain. The watershed namely Potpoto river watershed covering an area of 8160 hectares is situated in the vicinity of Ranchi, capital city of newly created Jharkahnd state. As per the national watershed atlas, Potpoto river is a tributary of Subarnarekha river system within the Upper Subarnarekha river basin under watershed no. 4H3C8. This rural to semi-urban watershed is important towards various services to Ranchi city as well as experiencing direct or indirect pressures of development. Drivers of land use changes at ground level are responsible for change in soil erosion rates in any watershed in coupled human-environment systems. This may adversely affect the soil cover of such watersheds depicted through changed rates of erosion. In a rural to semi-urban watershed like this, there are general tendencies of land use and thereby land cover changes from forests to agricultural lands, within agricultural land in terms of cropping pattern changes to cash-crops, orchards, commercial plantations and conversions to other land use categories as well towards infrastructure expansions. Universal Soil Loss Equation (USLE) was used as a basis to observe the intensity of erosion using remote sensing, rainfall data, soil data and land use/land cover map. IRS1C LISSIII and IRSP6 LISSIII data were used to identify land use status for the years 1996 and 2004 respectively. LISSIII sensor provides data in the visible to near infrared (Bands 2, 3, 4) as well as short wave infrared (Band 5) range of electromagnetic spectrum. In this study, bands 2 (0.52-0.59 microns), 3 (0.62-0.68 microns) and 4 (0.77-0.86 microns) were used with spatial resolution of 23.5 meters at nadir. Digital image processing was carried out using ERDAS Imagine software. Based on maximum likelihood classifier, the study area was classified into suitable land use/land cover classes. Digital elevation model (DEM) was created through contour heights from topographic maps. Watershed based erosion estimation was carried out including assessment of soil erosion due to land use land cover changes. This provides predictive assessment capability in soil erosion studies particularly with methods such as USLE. Soil erosion problem varies largely depending upon climate, topography, soil and land use etc. Multi-factor computations on rainfall erosivity, soil erodibility, topographic, cover and management, and conservation practice were carried out. Quantified details on soil erosion rates were generated in terms of land use land cover classes of the watershed for the years 1996 and 2004. Annual average soil loss for the watershed was calculated and erosion intensity maps were generated. Thus, space data utilized from the satellites IRS1C LISSIII and IRSP6 LISSIII greatly helped in important research assessment of an important land surface process like soil erosion spatially as well as temporally for a watershed under pressures of development, land use changes and land cover fragmentations.
NASA Astrophysics Data System (ADS)
Hanson, Z.; Patterson, T. A.; Grundel, R.; Bolster, D.; Hamlet, A. F.
2017-12-01
The Kankakee River watershed spans areas of southern Michigan, northern Indiana (IN), and eastern Illinois (IL), and was once home to one of the largest and most ecologically productive freshwater wetland complexes in North America, the 2400 km2 Grand Kankakee Marsh. The organically-rich marsh bottom land in the Kankakee basin also yielded productive farmland, but required extensive drainage. By 1919, more than 145 km of the 240-km-long river in IN were channelized and most of the wetlands in IN were drained. On the IL side, the river's channel system remained more intact, but the river was negatively affected by loss of wetland habitat upstream and increasing high flows, erosion and sediment transport arising from the hydrologic changes in the upstream areas. This study integrates surface water and groundwater modeling to explore the potential to recover a portion of the Kankakee's historic wetland ecosystem by removing agricultural drainage infrastructure within the basin. Results of wetland area and habitat metrics across the entire basin at coarse (500 m) resolution for several wetland restoration configurations and climate scenarios are presented, exhibiting the ability to successfully capture much of the watershed's historic features and traits as well as to respond to changes in model forcing to predict future wetland dynamics. Additionally, preliminary methods and results relating to a study site at finer (30 m) resolution over a moderate sized wetland restoration area ( 30 km2) are presented, helping to incorporate and address the fundamental interactions and limitations between agricultural practices and wetland restoration efforts within the entire Grand Kankakee Watershed.
Flood Assessment Area 3 Radioactive Waste Management Site, Nevada Test Site, Nye County, Nevada
DOE Office of Scientific and Technical Information (OSTI.GOV)
NSTec Environmental Management
2007-07-01
A flood assessment was conducted at the Area 3 Radioactive Waste Management Site (RWMS) at the Nevada Test Site (NTS) in Nye County, Nevada (Figure 1-1). The study area encompasses the watershed of Yucca Flat, a closed basin approximately 780 square kilometers (km2) (300 square miles) in size. The focus of this effort was on a drainage area of approximately 94 km2 (36 mi2), determined from review of topographic maps and aerial photographs to be the only part of the Yucca Flat watershed that could directly impact the Area 3 RWMS. This smaller area encompasses portions of the Halfpint Range,more » including Paiute Ridge, Jangle Ridge, Carbonate Ridge, Slanted Buttes, Cockeyed Ridge, and Banded Mountain. The Area 3 RWMS is located on coalescing alluvial fans emanating from this drainage area.« less
Hao, Lu; Pan, Cen; Fang, Di; Zhang, Xiaoyu; Zhou, Decheng; Liu, Peilong; Liu, Yongqiang; Sun, Ge
2018-10-15
Grazing is a major ecosystem disturbance in arid regions that are increasingly threatened by climate change. Understanding the long-term impacts of grazing on rangeland vegetation dynamics in a complex terrain in mountainous regions is important for quantifying dry land ecosystem services for integrated watershed management and climate change adaptation. However, data on the detailed long-term spatial distribution of grazing activities are rare, which prevents trend detection and environmental impact assessments of grazing. This study quantified the impacts of grazing on vegetation dynamics for the period of 1983-2010 in the Upper Heihe River basin, a complex multiple-use watershed in northwestern China. We also examined the relative contributions of grazing and climate to vegetation change using a dynamic grazing pressure method. Spatial grazing patterns and temporal dynamics were mapped at a 1 km × 1 km pixel scale using satellite-derived leaf area index (LAI) data. We found that overgrazing was a dominant driver for LAI reduction in alpine grasslands and shrubs, especially for the periods of 1985-1991 and 1997-2004. Although the recent decade-long active grazing management contributed to the improvement of LAI and partially offset the negative effects of increased livestock, overgrazing has posed significant challenges to shrub-grassland ecosystem recovery in the eastern part of the study basin. We conclude that the positive effects of a warming and wetting climate on vegetation could be underestimated if the negative long-term grazing effects are not considered. Findings from the present case study show that assessing long-term climate change impacts on watersheds must include the influences of human activities. Our study provides important guidance for ecological restoration efforts in locating vulnerable areas and designing effective management practices in the study watershed. Such information is essential for natural resource management that aims at meeting multiple demands of watershed ecosystem services in arid and semiarid rangelands. Copyright © 2018 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Luo, J.; Hochmuth, G.; Clark, M. W.
2014-12-01
Export of nitrogen from different watersheds across the United States is receiving increasing attention due to the impairment of water quality in receiving water bodies. Researchers have indicated that different land uses exerted a substantial influence on the water quality. Nitrogen loadings on the watershed scale are being studied in many large ecosystems, such as the Baltimore Ecosystem and Arizona Ecosystem, but only a few focuses in a smaller scale such as catchment scale. Characterization of the land use in catchment scale can better explain the observed environmental phenomena under the watershed scale and enrich the related watershed studies. Nitrogen fluxes have been studied at Lake Alice watershed in Gainesville, Florida with a focus on the rarely studied catchments such as sports fields with intensive fertilization management (SFC), urban area with reclaimed water irrigation (RWC) and urban area without irrigation (CC). The entire study started from May 2013. Discharge was monitored in the three catchments by transducers every 5 minutes. Regular biweekly grab samples in the three catchments were used to estimate the baseflow N loads, composite samples in 13 storms were collected to estimate the stormflow N loads. The results showed that in the baseflow, the average NO3-N concentration in SFC was 12.19 mg/l, which was significantly different from the urban catchments. Also there was a significant difference between the NO3-N concentrations in RWC (1.17 mg/l on average) and CC (0.60 mg/l on average). A separate log-log relationship was developed between discharge and N loads to estimate the baseflow N loads and stormflow N loads. It showed that baseflow contributed more N loads than stormflow in the three catchments in the annual N load. In conclusion, the recreational catchment received the greatest N load compared to the other catchments, so it should be the priority catchment when it comes to adopting nutrient management practices in the Lake Alice watershed.
Sources of suspended sediment in the Waikele watershed, Oʻahu, Hawaiʻi
Izuka, Scot K.
2012-01-01
Data from streamflow/sediment gages and measurements of changes in channel-bed sediment storage were gathered between October 1, 2007, and September 30, 2010, to assess the sources of suspended sediment in the Waikele watershed, Oʻahu, Hawaiʻi. Streamflow from the watershed averaged 33 cubic feet per second during the study period, with interannual variations corresponding with variations in the frequency and magnitude of storm-flow peaks. Average streamflow during the study period was lower than the long-term average, but the study period included a storm on December 11, 2008, that caused record-high streamflows in parts of the watershed. Suspended-sediment yield from the Waikele watershed during the study period averaged 82,500 tons per year, which is 2.7 times higher than the long-term average. More than 90 percent of the yield during the study period was discharged during the December 11, 2008, storm. The study-period results are consistent with long-term records that show that the vast majority of suspended-sediment transport occurs during a few large storms. Results of this study also show that all but a small percentage of the suspended-sediment yield came from hillslopes. Only a small fraction of bed sediments is fine enough to be transported as suspended load; most bed sediments in the watershed are coarse. Silt and clay constitute less than 3 percent of the bed-sediment volume on average. Some larger clasts, however, can disintegrate during transport and contribute to the suspended load downstream. During the study period, suspended-sediment yield from the urbanized Mililani subbasin averaged 25 tons per year per square mile (tons/yr/mi2), which was much smaller than the yield from any other subbasin; these results indicate that urban land use yields much less sediment than other land uses. The wet, forested Kipapa subbasin had an average normalized hillslope suspended-sediment yield of 386 tons/yr/mi2; the average yield for forested areas in the watershed may be lower. Suspended-sediment yield from agricultural land use in the watershed is estimated to range between 5,590 and 6,440 tons/yr/mi2 during the study period; the long-term average is estimated to be 2,070 to 2,390 tons/yr/mi2. Of the three land uses considered, agriculture had by far the highest normalized suspended-sediment yield during this study - about an order of magnitude higher than forests and two orders of magnitude higher than urban areas.
A Systematic Study of Zerbar Lake Restoration
NASA Astrophysics Data System (ADS)
Hosseini, Reza; Oveis Torabi, Seyed; Forman Asgharzadeh, Deonna
2017-04-01
The beautiful lake of Zerbar, located near Marivan City at the west of Iran, is a freshwater lake with an area of 20 km2 and average depth of 5 meters. The lake is created by regional tectonic activities and is mainly fed with natural spring water from bottom. During the past three decades, regional development has caused much disturbance to the natural environment of the lake and its watershed. Rescuing the lake is crucial to the sustainability of the whole region. The study of Zerbar Restoration was performed with the aim to restore its health indicators. Variety of human activities in the watershed, as well as the multidisciplinary nature of lake restoration studies, made it necessary to develop a systematic approach to conduct the study. In Step I of restoration studies, satellite images were investigated to identify the historical changes of watershed during the past 30 years. Meanwhile, documents since 50 years ago were studied. Results indicate that farmland and graze land areas have been relatively constant during the past 50 years. Also, the area of lake, its riparian canes and floating plants have not changed much. In fact, the only significant land use change observed was the significant spread of Marivan City that has stretched toward the lake. The main physical variation to the lake has been elevating the southern edge of the lake by a constructing a landfill dam which was done to control the lake's overflow discharge for irrigation of downstream farmland development. Step II consists of studies performed by disciplines of water resources, hydrogeology, water quality, wetland and watershed ecology, agriculture, animal farming and fishery. Study results indicate that eutrophication (TSL>100), mainly caused by sewage from Marivan City and the surrounding rural areas has been the main reason for lake ecosystem degradation. DPSIR framework, as a novel approach in lake restoration, was applied to synthesize the study results of different disciplines in a systematic manner. In step III, stakeholder engagement was investigated through constitution analysis. Meetings were held to communicate lake damages obtained and classified through DPSIR Framework to the stakeholders. Then, stakeholder participation in different actions was achieved through additional meetings. Finally in Step IV, crucial restoration actions were identified: residents to manage rural and urban sewage and waste disposal through local governance, to plan and perform complementary study of lake water treatment (physical, chemical and biochemical methods), to plan and perform bottom sediment refinement, restoring the lake's natural hydrodynamic condition by adjusting the outlet level, local communities to help prevent landuse change from agriculture to villas, triggering the watershed master plan study to enable watershed monitoring, investigating water quality and discharge of bottom springs to better understand the lake's hydrological cycle, and finally, local residents to protect riparian vegetation.
An Integrated Mobile Application to Improve the Watershed Management in Taiwan
NASA Astrophysics Data System (ADS)
Chou, T. Y.; Chen, M. H.; Lee, C. Y.
2015-12-01
This study aims to focus on the application of information technology on the reservoir watershed management. For the civil and commercial water usage, reservoirs and its upstream plays a significant role due to water scarcity and inequality, especially in Taiwan. Due to the progress of information technology, apply it can improve the efficiency and accuracy of daily affairs significantly which already proved by previous researches. Taipei Water Resource District (TWRD) is selected as study area for this study, it is the first reservoir watershed which authorized as special protection district by urban planning act. This study has designed a framework of mobile application, which addressed three types of public affairs relate to watershed management, includes building management, illegal land-use investigation, and a dashboard of real time stream information. This mobile application integrated a dis-connected map and interactive interface to collect, record and calculate field information which helps the authority manage the public affairs more efficiency.
NASA Astrophysics Data System (ADS)
Bassam, S.; Ren, J.
2015-12-01
Runoff generated during heavy rainfall imposes quick, but often intense, changes in the flow of streams, which increase the chance of flash floods in the vicinity of the streams. Understanding the temporal response of streams to heavy rainfall requires a hydrological model that considers meteorological, hydrological, and geological components of the streams and their watersheds. SWAT is a physically-based, semi-distributed model that is capable of simulating water flow within watersheds with both long-term, i.e. annually and monthly, and short-term (daily and sub-daily) time scales. However, the capability of SWAT in sub-daily water flow modeling within large watersheds has not been studied much, compare to long-term and daily time scales. In this study we are investigating the water flow in a large, semi-arid watershed, Nueces River Basin (NRB) with the drainage area of 16950 mi2 located in South Texas, with daily and sub-daily time scales. The objectives of this study are: (1) simulating the response of streams to heavy, and often quick, rainfall, (2) evaluating SWAT performance in sub-daily modeling of water flow within a large watershed, and (3) examining means for model performance improvement during model calibration and verification based on results of sensitivity and uncertainty analysis. The results of this study can provide important information for water resources planning during flood seasons.
Sun, Ran-Hao; Chen, Li-Ding; Wang, Wei; Wang, Zhao-Ming
2012-06-01
Understanding the effect of land cover pattern on nutrient losses is of great importance in management of water resources. The extensive application of mechanism models is limited in large-scale watersheds owing to the intensive data and calibration requirements. On the other hand, the traditional landscape indexes only take the areas and types of land cover into account, considering less about their topographic features and spatial patterns. We constructed a location-weighted landscape index (LWLI) based on the Lorenz curve, which plots the cumulative proportion of areas for sink and source landscapes respectively against cumulative proportion of their relative location to the outlet in a watershed, including relative elevation, distance and slope. We assessed the effect of land cover pattern on total nitrogen losses in the Haihe River. Firstly, 26 watersheds were derived from 1: 250 000 digital elevation model (DEM), and their "source" and "sink" landscape types were identified from Landsat TM images in 2007. The source" landscapes referred to the paddy land, dry land and residential area, correspondingly the "sink" landscapes referred to the forest and grassland. Secondly, LWLI was calculated according to the landscape types and spatial patterns for each watershed. Thirdly, we accessed the effect of land cover pattern on total nitrogen (TN) flux according to the value of LWLI, comparing with the area proportion of sink-source landscapes. The correlation coefficients were different in three parts of Haihe River, i. e., 0.86, 0.67 and 0.65 in the Yanshan Mts, Taihang Mts and lower Haihe River. The results showed strong correlations between TN and LWLI in contrast to the weak correlations between TN and area proportion of sink and source landscape types. This study indicates the spatial pattern of land cover is essential for accessing the nutrient losses, and the location-weighted landscape pattern analysis may be an alternate to existing water quality models, especially in large watershed scales. The sink-source index is sufficiently simple that it can be compared across watersheds and be easily interpreted, and potentially be used in landscape pattern optimal designing and planning.
NASA Astrophysics Data System (ADS)
Hoang, L.; Mukundan, R.; Moore, K. E.; Owens, E. M.; Steenhuis, T. S.
2017-12-01
New York City (NYC)'s reservoirs supply over one billion gallons of drinking water each day to over nine million consumers in NYC and upstate communities. The City has invested more than $1.5 billion in watershed protection programs to maintain a waiver from filtration for the Catskill and Delaware Systems. In the last 25 years, the NYC Department of Environmental Protection (NYCDEP) has implemented programs in cooperation with upstate communities that include nutrient management, crop rotations, improvement of barnyards and manure storage, implementing tertiary treatment for Phosphorus (P) in wastewater treatment plants, and replacing failed septic systems in an effort to reduce P loads to water supply reservoirs. There have been several modeling studies evaluating the effect of agricultural Best Management Practices (BMPs) on P control in the Cannonsville watershed in the Delaware System. Although these studies showed that BMPs would reduce dissolved P losses, they were limited to farm-scale or watershed-scale estimates of reduction factors without consideration of the dynamic nature of overland flow and P losses from variable source areas. Recently, we developed the process-based SWAT-Hillslope (SWAT-HS) model, a modified version of the Soil and Water Assessment Tool (SWAT) that can realistically predict variable source runoff processes. The objective of this study is to use the SWAT-HS model to evaluate watershed protection programs addressing both point and non-point sources of P. SWAT-HS predicts streamflow very well for the Cannonsville watershed with a daily Nash Sutcliffe Efficiency (NSE) of 0.85 at the watershed outlet and NSE values ranging from 0.56 - 0.82 at five other locations within the watershed. Based on good hydrological prediction, we applied the model to predict P loads using detailed P inputs that change over time due to the implementation of watershed protection programs. Results from P model predictions provide improved projections of P loads and form a basis for evaluating the cumulative and individual effects of watershed protection programs.
Effects of mountain tea plantations on nutrient cycling at upstream watersheds
NASA Astrophysics Data System (ADS)
Lin, T.-C.; Shaner, P.-J. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.
2015-11-01
The expansion of agriculture to rugged mountains can exacerbate negative impacts of agricultural activities on ecosystem function. In this study, we monitored streamwater and rainfall chemistry of mountain watersheds at the Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportion of tea plantation cover, the higher the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater of the four mountain watersheds examined; on the other hand, the concentrations of the ions that are rich in soils (SO42-, Ca2+, Mg2+) did not increase with the proportion of tea plantation cover, suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. Of the two watersheds for which rainfall chemistry was available, the one with higher proportion of tea plantation cover had higher concentrations of ions in rainfall and retained less nitrogen in proportion to input compared to the more pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. As expected, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of NO3- in streamwater by more than 70 %, indicating that such a landscape configuration helps mitigate nutrient enrichment in aquatic systems even for watersheds with steep topography. We estimated that tea plantation at our study site contributed approximately 450 kg ha-1 yr-1 of NO3-N via streamwater, an order of magnitude greater than previously reported for agricultural lands around the globe, which can only be matched by areas under intense fertilizer use. Furthermore, we constructed watershed N fluxes to show that excessive leaching of N, and additional loss to the atmosphere via volatilization and denitrification can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of agricultural activities, especially excessive fertilization, on ecosystem nutrient cycling at mountain watersheds.
Norman, L.M.; Guertin, D.P.; Feller, M.
2008-01-01
The development of new approaches for understanding processes of urban development and their environmental effects, as well as strategies for sustainable management, is essential in expanding metropolitan areas. This study illustrates the potential of linking urban growth and watershed models to identify problem areas and support long-term watershed planning. Sediment is a primary source of nonpoint-source pollution in surface waters. In urban areas, sediment is intermingled with other surface debris in transport. In an effort to forecast the effects of development on surface-water quality, changes predicted in urban areas by the SLEUTH urban growth model were applied in the context of erosion-sedimentation models (Universal Soil Loss Equation and Spatially Explicit Delivery Models). The models are used to simulate the effect of excluding hot-spot areas of erosion and sedimentation from future urban growth and to predict the impacts of alternative erosion-control scenarios. Ambos Nogales, meaning 'both Nogaleses,' is a name commonly used for the twin border cities of Nogales, Arizona and Nogales, Sonora, Mexico. The Ambos Nogales watershed has experienced a decrease in water quality as a result of urban development in the twin-city area. Population growth rates in Ambos Nogales are high and the resources set in place to accommodate the rapid population influx will soon become overburdened. Because of its remote location and binational governance, monitoring and planning across the border is compromised. One scenario described in this research portrays an improvement in water quality through the identification of high-risk areas using models that simulate their protection from development and replanting with native grasses, while permitting the predicted and inevitable growth elsewhere. This is meant to add to the body of knowledge about forecasting the impact potential of urbanization on sediment delivery to streams for sustainable development, which can be accomplished in a virtual environment. Copyright ?? 2008 by Bellwether Publishing, Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Rao, N. S.; Easton, Z. M.; Lee, D. R.; Steenhuis, T. S.
2007-12-01
Nutrient runoff from agricultural fields threatens water quality and can impair habitats in many watersheds. Agencies consider these potential risks as they determine acceptable levels of nutrient loading. For example, in the New York City (NYC) watershed, the Environmental Protection Agency's Total Maximum Daily Load (TMDL) for phosphorus (P) has been set at 15μg P L-1 to protect against eutrophication and bacterial outbreaks. In the NYC watersheds agricultural Best Management Practices (BMPs) are the primary means to control nonpoint source P loading. BMPs include riparian buffers, filter strips, manure storage facilities, crop rotation, stripcropping, tree planting and nutrient management plans (NMPs). Water quality research on BMPs to date has included studies on site-specificity of different BMPs, short and long term BMP efficacy, and placement of BMPs with respect to critical source areas. A necessary complement to studies addressing water quality aspects of different BMPs are studies examining the cost-benefit aspects of BMPs. In general, there are installment, maintenance and opportunity costs associated with each BMP, and there are benefits, including cost share agreements between farmers and farm agencies, and increased efficiency of farm production and maintenance. Combining water quality studies and related cost-benefit analyses would help planners and watershed managers determine how best improve water quality. Our research examines the costs-benefit structure associated with BMP scenarios on a one-farm headwater watershed in the Catskill Mountains of NY. The different scenarios include "with and without" BMPs, combinations of BMPs, and different BMP placements across agricultural fields. The costs associated with each BMP scenarios are determined using information from farm agencies and watershed planning agencies. With these data we perform a cost-benefit analysis for the different BMP scenarios and couple the water quality modeling using the Variable Source Loading Function (VSLF) model (Schneiderman et al., 2007) with the cost-benefit analysis to look at the specific water quality and economic consequences of different watershed management scenarios. The results of our study will be useful for planners and watershed managers in determining how best to reduce nonpoint source pollution in a cost-effective manner. References Schneiderman, E.M., T.S. Steenhuis, D.J. Thongs, Z.M. Easton, M.S. Zion, G.F. Mendoza, M.T. Walter, and A.C. Neal. 2007. Incorporating variable source area hydrology into curve number based watershed loading functions. Hydrol. Proc. (In Press).
Estimating ground water yield in small research basins
Elon S. Verry
2003-01-01
An analysis of ground water recharge in 32 small research watersheds shows the average flow of ground water out of the watershed (deep seepage) is 45% of streamflow and ranges from 8 to 350 mm/year when apportioned over the watershed area. It is time to meld ground water and small watershed science. The use of we11 networks and the evaluation of ground water well...
Agroforestry systems in the Sonora River Watershed, Mexico: An example of effective land stewardship
Diego Valdez-Zamudio; Peter F. Ffolliot
2000-01-01
The Sonora River watershed is located in the central part of the state of Sonora,Mexico, and is one of the most important watersheds in the region. Much of the state's economy depends on the natural resources, products, and productive activities developed in this watershed. Many natural areas along the river and its tributaries have been converted to a large...
Multi-objective game-theory models for conflict analysis in reservoir watershed management.
Lee, Chih-Sheng
2012-05-01
This study focuses on the development of a multi-objective game-theory model (MOGM) for balancing economic and environmental concerns in reservoir watershed management and for assistance in decision. Game theory is used as an alternative tool for analyzing strategic interaction between economic development (land use and development) and environmental protection (water-quality protection and eutrophication control). Geographic information system is used to concisely illustrate and calculate the areas of various land use types. The MOGM methodology is illustrated in a case study of multi-objective watershed management in the Tseng-Wen reservoir, Taiwan. The innovation and advantages of MOGM can be seen in the results, which balance economic and environmental concerns in watershed management and which can be interpreted easily by decision makers. For comparison, the decision-making process using conventional multi-objective method to produce many alternatives was found to be more difficult. Copyright © 2012 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Tasdighi, A.; Arabi, M.
2014-12-01
Calibration of physically-based distributed hydrologic models has always been a challenging task and subject of controversy in the literature. This study is aimed to investigate how different physiographic characteristics of watersheds call for adaption of the methods used in order to have more robust and internally justifiable simulations. Haw Watershed (1300 sq. mi.) is located in the piedmont region of North Carolina draining into B. Everett Jordan Lake located in west of Raleigh. Major land covers in this watershed are forest (50%), urban/suburban (21%) and agriculture (25%) of which a large portion is pasture. Different hydrologic behaviors are observed in this watershed based on the land use composition and size of the sub-watersheds. Highly urbanized sub-watersheds show flashier hydrographs and near instantaneous hydrologic responses. This is also the case with smaller sub-watersheds with relatively lower percentage of urban areas. The Soil and Water Assessment Tool (SWAT) has been widely used in the literature for hydrologic simulation on daily basis using Soil Conservation Service Curve Number method (SCS CN). However, it has not been used as frequently using the sub-daily routines. In this regard there are a number of studies in the literature which have used coarse time scale (daily) precipitation with methods like SCS CN to calibrate SWAT for watersheds containing different types of land uses and soils reporting satisfying results at the outlet of the watershed. This is while for physically-based distributed models, the more important concern should be to check and analyze the internal processes leading to those results. In this study, the watershed is divided into several sub-watersheds to compare the performance of SCS CN and Green & Ampt (GA) methods on different land uses at different spatial scales. The results suggest better performance of GA compared to SCS CN for smaller and highly urbanized sub-watersheds although GA predominance is not very significant for the latter. Also, the better performance of GA in simulating the peak flows and flashy behavior of the hydrographs is notable. GA did not show a significant improvement over SCS CN in simulating the excess rainfall for larger sub-watersheds.
A micro-hydrology computation ordering algorithm
NASA Astrophysics Data System (ADS)
Croley, Thomas E.
1980-11-01
Discrete-distributed-parameter models are essential for watershed modelling where practical consideration of spatial variations in watershed properties and inputs is desired. Such modelling is necessary for analysis of detailed hydrologic impacts from management strategies and land-use effects. Trade-offs between model validity and model complexity exist in resolution of the watershed. Once these are determined, the watershed is then broken into sub-areas which each have essentially spatially-uniform properties. Lumped-parameter (micro-hydrology) models are applied to these sub-areas and their outputs are combined through the use of a computation ordering technique, as illustrated by many discrete-distributed-parameter hydrology models. Manual ordering of these computations requires fore-thought, and is tedious, error prone, sometimes storage intensive and least adaptable to changes in watershed resolution. A programmable algorithm for ordering micro-hydrology computations is presented that enables automatic ordering of computations within the computer via an easily understood and easily implemented "node" definition, numbering and coding scheme. This scheme and the algorithm are detailed in logic flow-charts and an example application is presented. Extensions and modifications of the algorithm are easily made for complex geometries or differing microhydrology models. The algorithm is shown to be superior to manual ordering techniques and has potential use in high-resolution studies.
33 CFR 238.5 - Comprehensive planning.
Code of Federal Regulations, 2014 CFR
2014-07-01
... changes in watershed conditions, and help to avoid short-sighted plans serving only localized situations. This planning is particularly important in areas where significant portions of a watershed are expected... characteristics of the watershed. Hydrologic changes must be projected for the period of analysis. In this effort...
33 CFR 238.5 - Comprehensive planning.
Code of Federal Regulations, 2011 CFR
2011-07-01
... changes in watershed conditions, and help to avoid short-sighted plans serving only localized situations. This planning is particularly important in areas where significant portions of a watershed are expected... characteristics of the watershed. Hydrologic changes must be projected for the period of analysis. In this effort...
33 CFR 238.5 - Comprehensive planning.
Code of Federal Regulations, 2012 CFR
2012-07-01
... changes in watershed conditions, and help to avoid short-sighted plans serving only localized situations. This planning is particularly important in areas where significant portions of a watershed are expected... characteristics of the watershed. Hydrologic changes must be projected for the period of analysis. In this effort...
33 CFR 238.5 - Comprehensive planning.
Code of Federal Regulations, 2013 CFR
2013-07-01
... changes in watershed conditions, and help to avoid short-sighted plans serving only localized situations. This planning is particularly important in areas where significant portions of a watershed are expected... characteristics of the watershed. Hydrologic changes must be projected for the period of analysis. In this effort...
Remote sensing requirements as suggested by watershed model sensitivity analyses
NASA Technical Reports Server (NTRS)
Salomonson, V. V.; Rango, A.; Ormsby, J. P.; Ambaruch, R.
1975-01-01
A continuous simulation watershed model has been used to perform sensitivity analyses that provide guidance in defining remote sensing requirements for the monitoring of watershed features and processes. The results show that out of 26 input parameters having meaningful effects on simulated runoff, 6 appear to be obtainable with existing remote sensing techniques. Of these six parameters, 3 require the measurement of the areal extent of surface features (impervious areas, water bodies, and the extent of forested area), two require the descrimination of land use that can be related to overland flow roughness coefficient or the density of vegetation so as to estimate the magnitude of precipitation interception, and one parameter requires the measurement of distance to get the length over which overland flow typically occurs. Observational goals are also suggested for monitoring such fundamental watershed processes as precipitation, soil moisture, and evapotranspiration. A case study on the Patuxent River in Maryland shows that runoff simulation is improved if recent satellite land use observations are used as model inputs as opposed to less timely topographic map information.
Irina P. Panyushkina; Steven W. Leavitt; Eugene W. Domack; Alex C. Wiedenhoeft
2015-01-01
Glacial deposition and fluvial/lacustrine sedimentation interact over terrains in central New York State to preserve a history of geological and hydrological events as well as hydroclimatic transitions. The lower reach of Fish Creek draining the eastern watershed of Oneida Lake, NY, is an area with prominent wood remains. This study explores a collection of 52 logs...
Harley G. Shaw
2006-01-01
The purpose of this study was to compare current woodland density and distribution in and around the dry upper Verde River watershed in northwestern Arizona with conditions prior to Anglo settlement. Historic conditions were assessed using early photographs and early diaries and reports. The expedition led by Amiel Weeks Whipple was retraced and areas described in 1854...
Environmental Fate of Sulfometuron Methyl in Southern Forest Watersheds
J.L. Michael; D.G. Neary
1988-01-01
This study evaluated the fate of sulfometuron methyl in large forest-land watersheds in typical soils of the southern United States. Sulfometuron methyl is active over a range of rates and is recommended at rates up to 0.63 kilograms active ingredient per hectare (kg ai/ha) in non-crop areas for the control of annual and perennial grasses, and broadleaved weeds. The...
Effect of Spatial Distribution and Connectivity of Urban Impervious Areas on Hydrologic Response
NASA Astrophysics Data System (ADS)
Khoshouei, F.; Basu, N. B.; Schnoor, J. L.
2012-12-01
Urbanization alters the hydrology of a watershed by increasing impervious areas which results in decreased infiltration and increased runoff. Total Impervious Area (TIA) has been extensively used as a metric to describe this impact. It has recently been recognized, however, that TIA is a necessary but not sufficient attribute to describe the hydrologic response of a watershed. The connectivity and spatial placement of the impervious areas play a significant role in altering streamflow distributions. While the importance of spatial metrics is well recognized, the actual magnitude of their impact has not been adequately quantified in a systematic manner. We assess the effect of the spatial distribution of impervious area on hydrologic response in six peri-urban watersheds with areas in the order of 15 sq km in Midwest. We use the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model from the Army Corp of Engineers for our exploration. GSSHA is a grid-based two-dimensional hydrologic model with 2D overland flow and 1D streamflow and infiltration. The models for the watersheds were calibrated and validated using discharge data from USGS streamflow database. The models were then used in a virtual experimentation mode to understand the variability in hydrologic response as a function of different patterns of urban expansion. A new metric, "Impervious Area Width Function- IAWF" was developed that captured the distribution of flow path lengths from impervious areas. This metric captured the difference in hydrologic response between two watersheds with the same total impervious area but different distributions. The results suggest that urban development in areas with longer travel time (far from outlet) results in higher peak flows.
Lee, S; Yeo, I-Y; Lang, M W; Sadeghi, A M; McCarty, G W; Moglen, G E; Evenson, G R
2018-06-07
Despite recognizing the importance of wetlands in the Coastal Plain of the Chesapeake Bay Watershed (CBW) in terms of ecosystem services, our understanding of wetland functions has mostly been limited to individual wetlands and overall catchment-scale wetland functions have rarely been investigated. This study is aimed at assessing the cumulative impacts of wetlands on watershed hydrology for an agricultural watershed within the Coastal Plain of the CBW using the Soil and Water Assessment Tool (SWAT). We employed two improved wetland modules for enhanced representation of physical processes and spatial distribution of riparian wetlands (RWs) and geographically isolated wetlands (GIWs). This study focused on GIWs as their hydrological impacts on watershed hydrology are poorly understood and GIWs are poorly protected. Multiple wetland scenarios were prepared by removing all or portions of the baseline GIW condition indicated by the U.S. Fish and Wildlife Service National Wetlands Inventory geospatial dataset. We further compared the impacts of GIWs and RWs on downstream flow (i.e., streamflow at the watershed outlet). Our simulation results showed that GIWs strongly influenced downstream flow by altering water transport mechanisms in upstream areas. Loss of all GIWs reduced both water routed to GIWs and water infiltrated into the soil through the bottom of GIWs, leading to an increase in surface runoff of 9% and a decrease in groundwater flow of 7% in upstream areas. These changes resulted in increased variability of downstream flow in response to extreme flow conditions. GIW loss also induced an increase in month to month variability of downstream flow and a decrease in the baseflow contribution to streamflow. Loss of all GIWs was shown to cause a greater fluctuation of downstream flow than loss of all RWs for this study site, due to a greater total water storage capacity of GIWs. Our findings indicate that GIWs play a significant role in controlling hydrological processes in upstream areas and downstream flow and, therefore, protecting GIWs is important for enhanced hydrological resilience to extreme flow conditions in this region. Copyright © 2018 Elsevier Ltd. All rights reserved.
Assessing the hydrologic response to wildfires in mountainous regions
NASA Astrophysics Data System (ADS)
Havel, Aaron; Tasdighi, Ali; Arabi, Mazdak
2018-04-01
This study aims to understand the hydrologic responses to wildfires in mountainous regions at various spatial scales. The Soil and Water Assessment Tool (SWAT) was used to evaluate the hydrologic responses of the upper Cache la Poudre Watershed in Colorado to the 2012 High Park and Hewlett wildfire events. A baseline SWAT model was established to simulate the hydrology of the study area between the years 2000 and 2014. A procedure involving land use and curve number updating was implemented to assess the effects of wildfires. Application of the proposed procedure provides the ability to simulate the hydrologic response to wildfires seamlessly through mimicking the dynamic of the changes due to wildfires. The wildfire effects on curve numbers were determined comparing the probability distribution of curve numbers after calibrating the model for pre- and post-wildfire conditions. Daily calibration and testing of the model produced very good
results. No-wildfire and wildfire scenarios were created and compared to quantify changes in average annual total runoff volume, water budgets, and full streamflow statistics at different spatial scales. At the watershed scale, wildfire conditions showed little impact on the hydrologic responses. However, a runoff increase up to 75 % was observed between the scenarios in sub-watersheds with high burn intensity. Generally, higher surface runoff and decreased subsurface flow were observed under post-wildfire conditions. Flow duration curves developed for burned sub-watersheds using full streamflow statistics showed that less frequent streamflows become greater in magnitude. A linear regression model was developed to assess the relationship between percent burned area and runoff increase in Cache la Poudre Watershed. A strong (R2 > 0.8) and significant (p < 0.001) positive correlation was determined between runoff increase and percentage of burned area upstream. This study showed that the effects of wildfires on hydrology of a watershed are scale-dependent. Also, using full streamflow statistics through application of flow duration curves revealed that the wildfires had a higher effect on peak flows, which may increase the risk of flash floods in post-wildfire conditions.
Joiner, John K.; Aulenbach, Brent T.; Landers, Mark N.
2014-01-01
The U.S. Geological Survey, in cooperation with Gwinnett County Department of Water Resources, established a Long-Term Trend Monitoring (LTTM) program in 1996. The LTTM program is a comprehensive, long-term, water-quantity and water-quality monitoring program designed to document and analyze the hydrologic and water-quality conditions of selected watersheds of Gwinnett County, Georgia. Water-quality monitoring initially began in six watersheds and was expanded to another six watersheds in 2001. As part of the LTTM program, streamflow, precipitation, water temperature, specific conductance, and turbidity were measured continuously at the 12 watershed monitoring stations for water years 2004–09. In addition, discrete water-quality samples were collected seasonally from May through October (summer) and November through April (winter), including one base-flow and three stormflow event composite samples, during the study period. Samples were analyzed for nutrients (nitrogen and phosphorus), total organic carbon, trace elements (total lead and total zinc), total dissolved solids, and total suspended sediment (total suspended solids and suspended-sediment concentrations). The sampling scheme was designed to identify variations in water quality both hydrologically and seasonally. The 12 watersheds were characterized for basin slope, population density, land use for 2009, and the percentage of impervious area from 2000 to 2009. Precipitation in water years 2004–09 was about 18 percent below average, and the county experienced exceptional drought conditions and below average runoff in water years 2007 and 2008. Watershed water yields, the percentage of precipitation that results in runoff, typically are lower in low precipitation years and are higher for watersheds with the highest percentages of impervious areas. A comparison of base-flow and stormflow water-quality samples indicates that turbidity and concentrations of total ammonia plus organic nitrogen, total nitrogen, total phosphorus, total organic carbon, total lead, total zinc, total suspended solids, and suspended-sediment concentrations increased with increasing discharge at all watersheds. Specific conductance, however, decreased during stormflow at all watersheds, and total dissolved solids concentrations decreased during stormflow at a few of the watersheds. Total suspended solids and suspended-sediment concentrations typically were two orders of magnitude higher in stormflow samples, turbidities were about 1.5 orders of magnitude higher, total phosphorus and total zinc were about one order of magnitude higher, and total ammonia plus organic nitrogen, total nitrogen, total organic carbon, and total lead were about twofold higher than in base-flow samples. Seasonal patterns and long-term trends in flow-adjusted water-quality concentrations were identified for five representative constituents—total nitrogen, total phosphorus, total zinc, total dissolved solids, and total suspended solids. Seasonal patterns for all five constituents were fairly similar, with higher concentrations in the summer and lower concentrations in the winter. Significant linear long-term trends in stormflow composite concentrations were identified for 36 of the 60 constituent-watershed combinations (5 constituents multiplied by 12 watersheds) for the period of record through water year 2011. Significant trends typically were decreasing for total nitrogen, total phosphorus, total suspended solids, and total zinc and increasing for total dissolved solids. Total dissolved solids and total suspended solids trends had the largest magnitude changes per year. Stream water loads were estimated for 10 water-quality constituents. These estimates represent the cumulative effects of watershed characteristics, hydrologic processes, biogeochemical processes, climatic variability, and human influences on watershed water quality. Yields, in load per unit area, were used to compare loads from watersheds with different sizes. A load estimation approach developed for the Gwinnett County LTTM program that incorporates storm-event composited samples was used with some minor modifications. This approach employs the commonly used regression-model method. Concentrations were modeled as a function of discharge, time, season, and turbidity to improve model predictions and reduce errors in load estimates. Total suspended solids annual loads have been identified in Gwinnett County’s Watershed Protection Plan for target performance criterion. The amount of annual runoff is the primary factor in determining the amount of annual constituent loads. Below average runoff during water years 2004–09, especially during water years 2006–08, resulted in corresponding below average loads. Variations in constituent yields between watersheds appeared to be related to various watershed characteristics. Suspended sediment (total suspended solids and suspended-sediment concentrations) along with constituents transported predominately in solid phase (total phosphorus, total organic carbon, total lead, and total zinc) and total dissolved solids typically had higher yields from watersheds that had high percentages of impervious areas or high basin slope. High total nitrogen yields were also associated with watersheds with high percentages of impervious areas. Low total nitrogen, total suspended solids, total lead, and total zinc yields appear to be associated with watersheds that have a low percentage of high-density development. Total suspended solids yields were lower in drought years, water years 2007–08, from the combined effects of less runoff and the result of fewer, lower magnitude storms, which likely resulted in less surface erosion and lower stream sediment transport.
NASA Astrophysics Data System (ADS)
Shadmehr, Mehdi; Bafekr, Gilava; Pirouz, Mortaza
2010-05-01
Karaj Dam is located in the middle part of Alborz Mountain and its distance from Capital city, Tehran, is 63 kilometers. Watershed area approximately is 1000 square kilometers, average rate of rainfall is 625 mm per year and watershed altitude is between 4900 to 1700 meters from open sea. Karaj Dam is as a drinking water source for Tehran and Karaj cities and 21000 hectares of agricultural irrigation. Our studies is connected with As, Pb, Sb, Hg, Mo contaminant elements . We used 194 rock samples for chemical analysis and 12 water quality control stations. Chemical analysis values of rocks in the GIS divided into different classes with regard to the standard allowable values. We used SRTM data to find major catchments area and small watershed basin area behind the dam. After the necessary calculations, we determined which small basin area can be important to make more elements to pollution. The results compared with 12 water quality control stations and direct connection between the chemical composition of the rocks and water contaminated that comes from that area are very obvious. Our Study shows that natural contaminations can be enter to cycle from the southern part of basin, 14 kilometers from dam to east. Water contaminations is located along Shahrestanak river to Shahrestanak bridge and then to Mahan factory. The catchment's area for this river has highest amount of As, Sb, Pb and water quality control stations close that area show high contamination.
NASA Astrophysics Data System (ADS)
Gallo, E. M.; Hogue, T. S.; Gold, M.; Mika, K.
2016-12-01
Dominguez Channel and Machado Lake watersheds are located in highly urbanized southern Los Angeles County. The 16 mile long channel that runs through the Dominguez Channel watershed (DCW) captures stormwater from a drainage area of 71 square miles and discharges directly into the Los Angeles Harbor. Machado Lake, located within the Machado Lake watershed (MLW) and directly adjacent to DCW, has a surface area of 40 acres and receives stormwater from 25 square miles. The water quality of receiving streams and waterbodies in DCW and MLW are increasingly polluted from stormwater runoff and highly concentrated areas of industrial activities. The main concern of water impairment within DCW includes copper and zinc while MLW is focused on nutrients, Total Nitrogen and Total Phosphorous. The implementation of Low Impact Developments (LIDs) and stormwater Best Management Practices (BMPs) within the watershed aim to mitigate the effects of urbanization by reducing pollutant loads, runoff volume, and storm peak flow. We utilize the EPA System for Urban Stormwater Treatment and Analysis INtegration (SUSTAIN) model in order to assess the impact of BMPs within the DCW and MLW watersheds by forecasting flow regimes and water quality time series data. Six compliance scenarios are simulated in SUSTAIN to assess pollutant load reduction and cost effectiveness. They each utilize a various suite of the five BMPs selected, which include vegetated swales, bioretention cells, dry ponds, infiltration trenches and porous pavement. Preliminary results show that while the six compliance options reduce pollutant loads by at least 73% in DCW, copper and zinc are only 9% and 50% in compliance, respectively, in terms of the wet weather TMDLs. This study further analyzes these results by comparing DCW to other previously modelled watersheds in Los Angeles, including Ballona Creek watershed and the Los Angeles River watershed. Observed water quality sampling from Machado Lake has shown the mean concentrations of nutrients well above the TMDLs. Machado Lake is currently being restored which includes the implementation BMPs. While the DCW is being modeled to determine the best scenarios for future BMP implementation, MLW is modeled to assess the efficacy of current BMPs to meet TMDL compliance.
NASA Astrophysics Data System (ADS)
Zimmer, Margaret A.; McGlynn, Brian L.
2018-03-01
Watersheds are three-dimensional hydrologic systems where the longitudinal expansion/contraction of stream networks, vertical connection/disconnection between shallow and deep groundwater systems, and lateral connectivity of these water sources to streams mediate runoff production and nutrient export. The connectivity of runoff source areas during both baseflow and stormflow conditions and their combined influence on biogeochemical fluxes remain poorly understood. Here we focused on a set of 3.3 and 48.4 ha nested watersheds (North Carolina, USA). These watersheds comprise ephemeral and intermittent runoff-producing headwaters and perennial runoff-producing lowlands. Within these landscape elements, we characterized the timing and magnitude of precipitation, runoff, and runoff-generating flow paths. The active surface drainage network (ASDN) reflected connectivity to, and contributions from, source areas that differed under baseflow and stormflow conditions. The baseflow-associated ASDN expanded and contracted seasonally, driven by the rise and fall of the seasonal water table. Superimposed on this were event-activated source area contributions driven by connectivity to surficial and shallow subsurface flow paths. Frequently activated shallow flow paths also caused increased in-stream dissolved organic carbon (DOC) concentrations with increases in runoff across both watershed scales. The spread and variability within this DOC-runoff relationship was driven by a seasonal depletion of DOC from continual shallow subsurface flow path activation and subsequent replenishment from autumn litterfall. Our findings suggest that hydrobiogeochemical signals at larger watershed outlets can be driven by the expansion, contraction, and connection of lateral, longitudinal, and vertical source areas with distinct runoff generation processes.
PARAMETRIC DISTANCE WEIGHTING OF LANDSCAPE INFLUENCE ON STREAMS
We present a parametric model for estimating the areas within watersheds whose land use best predicts indicators of stream ecological condition. We regress a stream response variable on the distance-weighted proportion of watershed area that has a specific land use, such as agric...
78 FR 58334 - Proposed Flood Hazard Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2013-09-23
.... Upper Great Miami, Indiana, Ohio Watershed Shelby County, Ohio, and Incorporated Areas Maps Available... De Tour Village Hall, 260 South Superior Street, De Tour Village, MI 49725. Erie County, Ohio, and... Watershed Lawrence County, Ohio, and Incorporated Areas Maps Available for Inspection Online at: www.fema...
Ecological impacts from roads may be the rule rather than the exception in most watersheds of the conterminous United States. We measured total area, and forestland area located within nine distances of the nearest road of any type in each of 2,108 watersheds nationwide. Overall,...
NASA Astrophysics Data System (ADS)
Chang, ChiaChi; Chan, HsunChuan; Jia, YaFei; Zhang, YaoXin
2017-04-01
Due to the steep topography, frail geology and concentrated rainfall in wet season, slope disaster occurred frequently in Taiwan. In addition, heavy rainfall induced landslides in upper watersheds. The sediment yield on the slopeland affects the sediment transport in the river. Sediment deposits on the river bed reduce the river cross section and change the flow direction. Furthermore, it generates risks to residents' lives and property in the downstream. The Taiwanese government has been devoting increasing efforts on the sedimentary management issues and on reduction in disaster occurrence. However, due to the limited information on the environmental conditions in the upper stream, it is difficult to set up the sedimentary monitoring equipment. This study used the upper stream of the Qingshuei River, the Alishan River, as a study area. In August 2009, Typhoon Morakot caused the sedimentation of midstream and downstream river courses in the Alishan River. Because there is no any sediment monitoring stations within the Alishan River watershed, the sediment yield values are hard to determine. The objective of this study is to establish a method to analyze the event-landslide sediment transport in the river on the upper watershed. This study numerically investigated the sediment transport in the Alishan River by using the KINEROS 2 model developed by the United States Department of Agriculture and the CCHE1D model developed by the National Center for Computational Hydroscience and Engineering. The simulated results represent the morphology changes in the Alishan River during the typhoon events. The results consist of a critical strategy reference for the sedimentary management for the Alishan River watershed.
NASA Astrophysics Data System (ADS)
Aufdenkampe, A. K.; Tarboton, D. G.; Horsburgh, J. S.; Mayorga, E.; McFarland, M.; Robbins, A.; Haag, S.; Shokoufandeh, A.; Evans, B. M.; Arscott, D. B.
2017-12-01
The Model My Watershed Web app (https://app.wikiwatershed.org/) and the BiG-CZ Data Portal (http://portal.bigcz.org/) and are web applications that share a common codebase and a common goal to deliver high-performance discovery, visualization and analysis of geospatial data in an intuitive user interface in web browser. Model My Watershed (MMW) was designed as a decision support system for watershed conservation implementation. BiG CZ Data Portal was designed to provide context and background data for research sites. Users begin by creating an Area of Interest, via an automated watershed delineation tool, a free draw tool, selection of a predefined area such as a county or USGS Hydrological Unit (HUC), or uploading a custom polygon. Both Web apps visualize and provide summary statistics of land use, soil groups, streams, climate and other geospatial information. MMW then allows users to run a watershed model to simulate different scenarios of human impacts on stormwater runoff and water-quality. BiG CZ Data Portal allows users to search for scientific and monitoring data within the Area of Interest, which also serves as a prototype for the upcoming Monitor My Watershed web app. Both systems integrate with CUAHSI cyberinfrastructure, including visualizing observational data from CUAHSI Water Data Center and storing user data via CUAHSI HydroShare. Both systems also integrate with the new EnviroDIY Water Quality Data Portal (http://data.envirodiy.org/), a system for crowd-sourcing environmental monitoring data using open-source sensor stations (http://envirodiy.org/mayfly/) and based on the Observations Data Model v2.
The use of snowcovered area in runoff forecasts
NASA Technical Reports Server (NTRS)
Rango, A.; Hannaford, J. F.; Hall, R. L.; Rosenzweig, M.; Brown, A. J.
1977-01-01
Long-term snowcovered area data from aircraft and satellite observations have proven useful in reducing seasonal runoff forecast error on the Kern river watershed. Similar use of snowcovered area on the Kings river watershed produced results that were about equivalent to methods based solely on conventional data. Snowcovered area will be most effective in reducing forecast procedural error on watersheds with: (1) a substantial amount of area within a limited elevation range; (2) an erratic precipitation and/or snowpack accumulation pattern not strongly related to elevation; and (3) poor coverage by precipitation stations or snow courses restricting adequate indexing of water supply conditions. When satellite data acquisition and delivery problems are resolved, the derived snowcover information should provide a means for enhancing operational streamflow forecasts for areas that depend primarily on snowmelt for their water supply.
Impact of Fire on Streamflow in Southern California Watersheds
NASA Astrophysics Data System (ADS)
Bart, R. R.; Hope, A. S.
2007-12-01
Post-fire streamflow dynamics in Southern California have primarily been studied using small watershed experiments. These studies have concluded that increases in streamflow are a consequence of an increase in soil hydrophobicity, along with a decrease in transpiration rates associated with less vegetation. Extrapolation of the results from these studies to large watersheds (>50 km2) has been limited because large watersheds may not burn completely and other processes may emerge at these scales. In this study, six paired watersheds were used to test the hypothesis that there is an increase in streamflow following fire in large California watersheds (54-632 km2). The percentage of area burned in these watersheds ranged from 23 to 100%. The effects of fires on streamflow were examined at annual, seasonal, and monthly time-steps for the five years following fire. In addition, this study attempted to address fundamental regression assumptions that are commonly ignored, and create uncertainty bounds for evaluating the changes in streamflow before and after fire. Results of this experiment indicate that differences in pre and post-fire streamflows, at all time scales and in all the test catchments, were generally within the 95% uncertainty bounds of the regression equation. It is uncertain whether the apparent lack of significant difference between the pre and post-fire streamflow reflects no actual change in streamflow or is a consequence of the errors and uncertainties in the streamflow data. Furthermore, persistent drought in the years following fire made it challenging to interpret differences in pre and post-fire flows using the paired watershed methodology. The effects of hydrophobicity on post-fire streamflow may have been reduced by a limited number of storm flow events during these drought years. Under these dry conditions, soil moisture was the dominant control over transpirational losses, minimizing the effects of a reduction in vegetation cover. These results indicate that the consequences of fires are likely to vary depending on the post-fire meteorological conditions. The study addresses the challenges of using non-experimental watersheds for paired watershed studies.
Groundwater quality in the Bear Valley and Lake Arrowhead Watershed, California
Mathany, Timothy; Burton, Carmen; Fram, Miranda S.
2017-06-20
Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Bear Valley and Lake Arrowhead Watershed study areas in southern California compose one of the study units being evaluated.
Baker, Nancy T.; Stone, Wesley W.; Frey, Jeffrey W.; Wilson, John T.
2007-01-01
The study of agricultural chemicals is one of five national priority topics being addressed by the National Water-Quality Assessment (NAWQA) Program in its second decade of studies, which began in 2001. Seven watersheds across the Nation were selected for the NAWQA agricultural-chemical topical study. The watersheds selected represent a range of agricultural settings - with varying crop types and agricultural practices related to tillage, irrigation, artificial drainage, and chemical use - as well as a range of landscapes with different geology, soils, topography, climate, and hydrology (Capel and others, 2004). Chemicals selected for study include nutrients (nitrogen and phosphorus) and about 50 commonly used pesticides. This study design leads to an improved understanding of many factors that can affect the movement of water and chemicals in different agricultural settings. Information from these studies will help with decision making related to chemical use, conservation, and other farming practices that are used to reduce runoff of agricultural chemicals and sediment from fields (Capel and others, 2004). This Fact Sheet highlights the results of the NAWQA agricultural chemical study in the Leary Weber Ditch Watershed in Hancock County, Indiana. This watershed was selected to represent a tile-drained, corn and soybean, humid area typical in the Midwest.
Terrio, Paul J.
2006-01-01
Concentrations, spatial and temporal variations, and fluxes of nitrogen, phosphorus, and suspended sediment were determined for 16 streams in the Illinois River Basin, Illinois from October 1996 through September 2000. Water samples were collected through the National Water-Quality Assessment's Lower Illinois River Basin (LIRB) and Upper Illinois River Basin (UIRB) Study Units on a monthly to weekly frequency from watersheds representing predominantly agricultural and urban land, as well as areas of mixed land-use. Streams in agricultural watersheds had high concentrations and fluxes of nitrate nitrogen, whereas streams in predominantly urban watersheds had high concentrations (above background levels) of ammonia nitrogen, organic nitrogen, and phosphorus. Median concentrations of nitrate nitrogen and total phosphorus were similar at the two Illinois River sampling stations (Illinois River at Ottawa, Ill. and Illinois River at Valley City, Ill.) that represented the downstream points of the UIRB and LIRB Study Units, respectively, and integrated multiple land-use areas. Concentrations of nitrogen were typically highest in the spring and lowest in the fall in agricultural watersheds, but highest in the winter in urban watersheds. Phosphorus concentrations in urban watersheds were highest in the fall and winter, but there was minimal seasonal variation in phosphorus concentrations in agricultural watersheds. Concentrations of nitrate and total nitrogen were affected primarily by non-point sources and hydrologic factors such as streamflow, storm intensity, watershed configuration, and soil permeability, whereas concentrations of phosphorus were affected largely by point-source contributions that typically have little seasonal variation. Seasonal variation in hydrologic conditions was an important factor for seasonal variation in nutrient concentration. Fluxes and yields of nitrogen and phosphorus forms varied substantially throughout the Illinois River Basin, and yields of specific nutrient forms were determined primarily by upstream land uses. Yields of nitrate nitrogen were highest in predominantly agricultural watersheds, whereas yields of phosphorus and ammonia nitrogen were highest in urban watersheds with wastewater effluent contributions. Yields of both total nitrogen and total phosphorus were similar at the two Illinois River stations representing the integrated UIRB and LIRB Study Units. Concentrations of suspended sediment ranged from 1 to 3,110 milligrams per liter (mg/L), with median concentrations generally higher in the UIRB. Suspended-sediment concentrations were highest and most variable in the LaMoine River Basin. The median concentration of suspended sediment in the Illinois River at Valley City, Ill. (155 mg/L) was twice as high as that at Ottawa, Ill. (80 mg/L). Fluxes of suspended sediment generally corresponded to watershed size and yields from agricultural watersheds were larger than yields from urban watersheds. The flux in the Illinois River at Valley City, Ill. (4,880,000 tons per year) was approximately four times the flux in the Illinois River at Ottawa, Ill. (1,060,000 tons per year).
NASA Astrophysics Data System (ADS)
Zhou, Z.; Smith, J. A.; Yang, L.; Baeck, M. L.; Liu, S.; Ten Veldhuis, M. C.
2016-12-01
The objective of this study is to develop a broad characterization of land surface and hydrometeorological controls of urban flood frequency. We focus on a collection of "small" urban watersheds (with drainage area ranging from 7 to 200 km2) in Charlotte metropolitan region, North Carolina. These watersheds are contrasted by a variety of land surface properties, such as size, shape, land use/land cover type, impervious coverage pattern, stormwater infrastructure, etc. We carried out empirical analyses based on long-term (15 years), high-resolution (1 15 minutes) instantaneous USGS stream gaging observations as well as bias-corrected, high-resolution (1 km2, 15 min) radar rainfall fields developed through the Hydro-NEXRAD system. Extreme floods in Charlotte urban watersheds are primarily induced by a mixture of flood agents including warm season thunderstorms and tropical cyclones, which ultimately contributed to the upper-tail properties of flood frequency. Flood response in urban watersheds is dominantly dictated by space-time characteristics of rainfall, with relatively significant correlation between runoff and rainfall over more developed watersheds. The roles of antecedent soil moisture and stormwater management infrastructure in flood response are also contrasted across the urban watersheds. The largest variability of flood response, in terms of flood peak and timing, exists in the watershed at a scale of 100 km2. The scale-dependent hydrological response is closely related to the pattern and evolution of urban development across watersheds. Our analyses show the complexities of urban flood response in Charlotte metropolitan region. There are no simple metrics that could perfectly explain the contrasts in flood response across urban watersheds. Future research is directed towards sophisticated modeling studies for a predictive understanding of flood frequency in urban watersheds.
Zhao, Yaolong; Zhang, Ke; Fu, Yingchun; Zhang, Hong
2012-10-24
Monitoring land-use/land-cover change (LULCC) and exploring its mechanisms are important processes in the environmental management of a lake watershed. The purpose of this study was to examine the spatiotemporal pattern of LULCC by using multi landscape metrics in the Lake Dianchi watershed, which is located in the Yunnan-Guizhou Plateau of Southwest China. Landsat images from the years 1974, 1988, 1998, and 2008 were analyzed using geographical information system (GIS) techniques. The results reveal that land-use/land-cover has changed greatly in the watershed since 1974. This change in land use structure was embodied in the rapid increase of developed areas with a relative change rate of up to 324.4%. The increase in developed areas mainly occurred in agricultural land, especially near the shores of Lake Dianchi. The spatial pattern and structure of the change was influenced by the urban sprawl of the city of Kunming. The urban sprawl took on the typical expansion mode of cyclic structures and a jigsaw pattern and expanded to the shore of Lake Dianchi. Agricultural land changed little with respect to the structure but changed greatly in the spatial pattern. The landscape in the watershed showed a trend of fragmentation with a complex boundary. The dynamics of land-use/land-cover in the watershed correlate with land-use policies and economic development in China.
Zhao, Yaolong; Zhang, Ke; Fu, Yingchun; Zhang, Hong
2012-01-01
Monitoring land-use/land-cover change (LULCC) and exploring its mechanisms are important processes in the environmental management of a lake watershed. The purpose of this study was to examine the spatiotemporal pattern of LULCC by using multi landscape metrics in the Lake Dianchi watershed, which is located in the Yunnan-Guizhou Plateau of Southwest China. Landsat images from the years 1974, 1988, 1998, and 2008 were analyzed using geographical information system (GIS) techniques. The results reveal that land-use/land-cover has changed greatly in the watershed since 1974. This change in land use structure was embodied in the rapid increase of developed areas with a relative change rate of up to 324.4%. The increase in developed areas mainly occurred in agricultural land, especially near the shores of Lake Dianchi. The spatial pattern and structure of the change was influenced by the urban sprawl of the city of Kunming. The urban sprawl took on the typical expansion mode of cyclic structures and a jigsaw pattern and expanded to the shore of Lake Dianchi. Agricultural land changed little with respect to the structure but changed greatly in the spatial pattern. The landscape in the watershed showed a trend of fragmentation with a complex boundary. The dynamics of land-use/land-cover in the watershed correlate with land-use policies and economic development in China. PMID:23202820
NASA Astrophysics Data System (ADS)
Rasoulzadeh Gharibdousti, S.; Kharel, G.; Stoecker, A.; Storm, D.
2016-12-01
One of the main causes of water quality impairment in the United States is human induced Non-Point Source (NPS) pollution through intensive agriculture. Fort Cobb Reservoir (FCR) watershed located in west-central Oklahoma, United States is a rural agricultural catchment with known issues of NPS pollution including suspended solids, siltation, nutrients, and pesticides. The FCR watershed with an area of 813 km2 includes one major lake fed by four tributaries. Recently, several Best Management Practices (BMPs) have been implemented in the watershed (such as no-tillage and cropland to grassland conversion) to improve water quality. In this study we aim to estimate the effectiveness of different BMPs in improving watershed health under future climate projections. We employed the Soil and Water Assessment Tool (SWAT) to develop the hydrological model of the FCR watershed. The watershed was delineated using the 10 m USGS Digital Elevation Model and divided into 43 sub-basins with an average area of 8 km2 (min. 0.2 km2 - max. 28 km2). Through a combination of Soil Survey Geographic Database- SSURGO soil data, the US Department of Agriculture crop layer and the slope information, the watershed was further divided into 1,217 hydrologic response units. The historical climate pattern in the watershed was represented by two different weather stations. The model was calibrated (1991 - 2000) and validated (2001 - 2010) against the monthly USGS observations of streamflow recorded at the watershed outlet using three statistical matrices: coefficient of determination (R2), Nash-Sutcliffe efficiency (NS) and percentage bias (PB). Model parametrization resulted into satisfactory values of R2 (0.56) and NS (0.56) in calibration period and an excellent model performance (R2 = 0.75; NS = 0.75; PB = <1) in validation period. We have selected 19 BMPs to estimate their efficacy in terms of water and sediment yields under a combination of three Coupled Model Intercomparison Project-5 Global Climate Model projections and two concentration pathways (4.5 and 8.5) downscaled to the FCR watershed. The model results provide precise information for stakeholders to prioritize ecologically sound and economically feasible BMPs that are capable of mitigating future climate change impacts at the watershed scale.
NASA Astrophysics Data System (ADS)
Rice, Joshua S.; Emanuel, Ryan E.
2017-05-01
Understanding the factors that influence how global climate phenomena, such as the El-Nino Southern Oscillation (ENSO), affect streamflow behavior is an important area of research in the hydrologic sciences. While large-scale patterns in ENSO-streamflow relationships have been thoroughly studied, and are relatively well-understood, information is scarce concerning factors that affect variation in ENSO responses from one watershed to another. To this end, we examined relationships between variability in ENSO activity and streamflow for 2731 watersheds across the conterminous U.S. from 1970 to 2014 using a novel approach to account for the intermediary role of precipitation. We applied an ensemble of regression techniques to describe relationships between variability in ENSO activity and streamflow as a function of watershed characteristics including: hydroclimate, topography, geomorphology, geographic location, land cover, soil characteristics, bedrock geology, and anthropogenic influences. We found that variability in watershed scale ENSO-streamflow relationships was strongly related to factors including: precipitation timing and phase, forest cover, and interactions between watershed topography and geomorphology. These, and other influential factors, share in common the ability to affect the partitioning and movement of water within watersheds. Our results demonstrate that the conceptualization of watersheds as signal filters for hydroclimate inputs, commonly applied to short-term rainfall-runoff responses, also applies to long-term hydrologic responses to sources of recurrent climate variability. These results also show that watershed processes, which are typically studied at relatively fine spatial scales, are also critical for understanding continental scale hydrologic responses to global climate.
Hambrook Berkman, Julie A.; Scudder, Barbara C.; Lutz, Michelle A.; Harris, Mitchell A.
2010-01-01
This study evaluated the relations between algal, invertebrate, and fish assemblages and physical environmental characteristics of streams at the reach, segment, and watershed scale in agricultural settings in the Midwest. The 86 stream sites selected for study were in predominantly agricultural watersheds sampled as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Species abundance and over 130 biological metrics were used to determine which aspects of the assemblages were most sensitive to change at the three spatial scales. Digital orthophotograph-based riparian land use/land cover was used for analyses of riparian conditions at the reach and segment scales. The percentage area of different land-use/land-cover types was also determined for each watershed. Out of over 230 environmental characteristics examined, those that best explained variation in the biotic assemblages at each spatial scale include the following: 1) reach: bank vegetative cover, fine silty substrate, and open canopy angle; 2) segment: woody vegetation and cropland in the 250-m riparian buffer, and average length of undisturbed buffer; and 3) watershed: land use/land cover (both total forested and row crop), low-permeability soils, slope, drainage area, and latitude. All three biological assemblages, especially fish, correlated more with land use/land cover and other physical characteristics at the watershed scale than at the reach or segment scales. This study identifies biotic measures that can be used to evaluate potential improvements resulting from agricultural best-management practices and other conservation efforts, as well as evaluate potential impairment from urban development or other disturbances.
Sap Flow Estimate Of Watershed-Scale Transpiration
NASA Astrophysics Data System (ADS)
Kumagai, T.; Aoki, S.; Shimizu, T.; Otsuki, K.
2006-12-01
The present study examined how to obtain sufficient information to extrapolate watershed-scale transpiration in a Japanese cedar (Cryptomeria japonica D. Don) forest from sap flow measurements of available individual trees. In this study, we conducted measurements of tree biometrics and tree-to-tree and radial variations in xylem sap flux density (Fd) in two different stand plots, an upper slope plot (UP) and lower slope plot (LP), during the growing season with significant variations in environmental factors. The manner in which the mean stand sap flux density (JS) and tree stem allometric relationship (diameter at breast height (DBH) versus sapwood area (AS_tree)) vary between the two stands along the slope of the watershed was then investigated. After these analyses, appropriate sample sizes for estimations of representative JS values in the stand were also determined. The results demonstrated that a unique or general function allowed description of the allometric relationship along the slope, but the data for its formulation needed to be obtained in both UP and LP. They also revealed that JS in UP and LP were almost the same during the study period despite differences in tree density and size between the two plots. This implies that JS measured in a partial stand within a watershed is a reasonable estimator of the values of other stands, and that stand sapwood area calculated by AS_tree is a strong determinant of water-use in a forest watershed. To estimate JS in both an UP and LP, at least 10 trees should be sampled, but not necessarily more than this.
The behaviour of 39 pesticides in surface waters as a function of scale
Capel, P.D.; Larson, S.J.; Winterstein, T.A.
2001-01-01
A portion of applied pesticides runs off agricultural fields and is transported through surface waters. In this study, the behaviour of 39 pesticides is examined as a function of scale across 14 orders of magnitude from the field to the ocean. Data on pesticide loads in streams from two US Geological Survey programs were combined with literature data from field and watershed studies. The annual load as percent of use (LAPU) was quantified for each of the fields and watersheds and was used as the normalization factor across watersheds and compounds. The in-stream losses of each pesticide were estimated for a model stream with a 15 day travel time (similar in characteristics to the upper Mississippi River). These estimated in-stream losses agreed well with the observed changes in apparent LAPU values as a function of watershed area. In general, herbicides applied to the soil surface had the greatest LAPU values and minimal in-stream losses. Soil-incorporated herbicides had smaller LAPU values and substantial in-stream losses. Insecticides generally had LAPU values similar to the incorporated herbicides, but had more variation in their in-stream losses. On the basis of the LAPU values of the 39 pesticides as a function of watershed area, a generalized conceptual model of the movement of pesticides from the field to the ocean is suggested. The importance of considering both field runoff and in-stream losses is discussed in relation to interpreting monitoring data and making regulatory decisions.
Cheng, Xiaoya; Shaw, Stephen B; Marjerison, Rebecca D; Yearick, Christopher D; DeGloria, Stephen D; Walter, M Todd
2014-05-01
Predicting runoff producing areas and their corresponding risks of generating storm runoff is important for developing watershed management strategies to mitigate non-point source pollution. However, few methods for making these predictions have been proposed, especially operational approaches that would be useful in areas where variable source area (VSA) hydrology dominates storm runoff. The objective of this study is to develop a simple approach to estimate spatially-distributed risks of runoff production. By considering the development of overland flow as a bivariate process, we incorporated both rainfall and antecedent soil moisture conditions into a method for predicting VSAs based on the Natural Resource Conservation Service-Curve Number equation. We used base-flow immediately preceding storm events as an index of antecedent soil wetness status. Using nine sub-basins of the Upper Susquehanna River Basin, we demonstrated that our estimated runoff volumes and extent of VSAs agreed with observations. We further demonstrated a method for mapping these areas in a Geographic Information System using a Soil Topographic Index. The proposed methodology provides a new tool for watershed planners for quantifying runoff risks across watersheds, which can be used to target water quality protection strategies. Copyright © 2014 Elsevier Ltd. All rights reserved.
Development of potential map for landslides by comparing instability indices of various time periods
NASA Astrophysics Data System (ADS)
Chiang, Jie-Lun; Tian, Yu-Qing; Chen, Yie-Ruey; Tsai, Kuang-Jung
2017-04-01
In recent years, extreme rainfall events occur frequently and induced serious landslides and debris flow disasters in Taiwan. The instability indices will differ when using landslide maps of different time periods. We analyzed the landslide records during the period year, 2008 2012, the landslide area contributed 0.42% 2.94% of the total watershed area, the 2.94% was caused by the typhoon Morakot in August, 2009, which brought massive rainfall in which the cumulative maximum rainfall was up to 2900 mm. We analyzed the instability factors including elevation, slope, aspect, soil, and geology. And comparing the instability indices by using individual landslide map of 2008 2012, the landslide maps of the union of the five years, and interaction of the five years. The landslide area from union of the five years contributed 3.71%,the landslide area from interaction of the five years contributed 0.14%. In this study, Kriging was used to establish the susceptibility map in selected watershed. From interaction of the five years, we found the instability index above 4.3 can correspond to those landslide records. The potential landslide area of the selected watershed, where collapses occur more likely, belongs to high level and medium-high level; the area is 13.43% and 3.04% respectively.
Variation of the anthropic vulnerability in Ribeirão das Pedras watershed in Campinas/SP - Brazil.
NASA Astrophysics Data System (ADS)
Damame, Desirée; Longo, Regina; Ribeiro, Admilson; Fengler, Felipe
2015-04-01
The human actions has caused over the years profound changes in environmental quality in urban ecosystems suffering losses in the quality of air, soil , water and vegetation also the quality of life of the population that inhabit these areas . The study area is characterized by being a highly urbanized watershed, with about 43 % of its area covered by buildings, houses , and commercial and industrial establishments . Called the Ribeirão das Pedras Basin, located in Campinas / SP - Brazil and is bounded by coordinates 22˚47'10 '' and 22˚52'20 '' S , and 47˚ 07'15 '' and 46˚ 02 ' 15' ' . Has an average temperature of 22.4 ° C and average annual rainfall of 1424.5 mm . It has an area of about 42 km² . This is located two universities and a large mall. It also demands a strong agriculture , which occupies about 30 % of the area . It has also been part of two major forest reserves of the municipality, the Forest Santa Geneva and the Forest of Quilombo , both added to other small fragments overlying only about 6% of the total basin area . Avalição to environmental quality , the analysis of the vulnerability of urban watershed becomes an important environmental management tool. The vulnerability can be defined by susceptibility to changes of environment in its initial state , a current tax status by human intervention , and is almost always associated with risk , and the intensity at which such projects in one place, person or structure. In this context , this study aimed to assess environmental vulnerability in an urban watershed coming under increasing human pressures , especially in recent years . For this analysis were prepared soil graphics, slope , elevation and land use and land cover for the years 2009 and 2014 , generating with these , comparative anthropic vulnerability maps of the past five years. Crafting vulnerability maps is a sensitivity in order to enable appropriate management of biotic systems. With the results can be seen that the variation of anthropogenic vulnerability in the study area took place mainly by the real estate growth that the area has suffered in recent years, due to the large enhancement of the region , both for businesses and homes , as for industrial area. It was found that the distribution of anthropogenic vulnerability for 2009 was 19% too low, 33% low, 40 % moderate , high 8% and 0% too high. 2014 was obtained by dividing the current scenario is as follows: 10% very low , low 31% , moderate 50% , 9% and 0% high too high, meaning that there was an increase in high vulnerability points and moderate and still , a very significant decrease for low and very low vulnerability , revealing the strong environmental impact that the area has been suffering . Thus, we can conclude that the housing boom in large areas impacts the vulnerability of a watershed , which will certainly affect both the areas of forest / native fragments , and subsequently the quality of life of the surrounding population. In the specific case of Ribeirão das Pedras watershed , knowing the strong agricultural occupation of the area , it is known that the increased fragility still imply large losses for food production in the region.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bostick, Kent; Daniel, Anamary; Tachiev, Georgio
2013-07-01
In this case study, groundwater/surface water modeling was used to determine efficacy of stabilization in place with hydrologic isolation for remediation of mercury contaminated areas in the Upper East Fork Poplar Creek (UEFPC) Watershed in Oak Ridge, TN. The modeling simulates the potential for mercury in soil to contaminate groundwater above industrial use risk standards and to contribute to surface water contamination. The modeling approach is unique in that it couples watershed hydrology with the total mercury transport and provides a tool for analysis of changes in mercury load related to daily precipitation, evaporation, and runoff from storms. The modelmore » also allows for simulation of colloidal transport of total mercury in surface water. Previous models for the watershed only simulated average yearly conditions and dissolved concentrations that are not sufficient for predicting mercury flux under variable flow conditions that control colloidal transport of mercury in the watershed. The transport of mercury from groundwater to surface water from mercury sources identified from information in the Oak Ridge Environmental Information System was simulated using a watershed scale model calibrated to match observed daily creek flow, total suspended solids and mercury fluxes. Mercury sources at the former Building 81-10 area, where mercury was previously retorted, were modeled using a telescopic refined mesh with boundary conditions extracted from the watershed model. Modeling on a watershed scale indicated that only source excavation for soils/sediment in the vicinity of UEFPC had any effect on mercury flux in surface water. The simulations showed that colloidal transport contributed 85 percent of the total mercury flux leaving the UEFPC watershed under high flow conditions. Simulation of dissolved mercury transport from liquid elemental mercury and adsorbed sources in soil at former Building 81-10 indicated that dissolved concentrations are orders of magnitude below a target industrial groundwater concentration beneath the source and would not influence concentrations in surface water at Station 17. This analysis addressed only shallow concentrations in soil and the shallow groundwater flow path in soil and unconsolidated sediments to UEFPC. Other mercury sources may occur in bedrock and transport though bedrock to UEFPC may contribute to the mercury flux at Station 17. Generally mercury in the source areas adjacent to the stream and in sediment that is eroding can contribute to the flux of mercury in surface water. Because colloidally adsorbed mercury can be transported in surface water, actions that trap colloids and or hydrologically isolate surface water runoff from source areas would reduce the flux of mercury in surface water. Mercury in soil is highly adsorbed and transport in the groundwater system is very limited under porous media conditions. (authors)« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hale, Rebecca L.; Turnbull, Laura; Earl, Stevan
Urban watersheds are often sources of nitrogen (N) to downstream systems, contributing to poor water quality. However, it is unknown which components (e.g., land cover and stormwater infrastructure type) of urban watersheds contribute to N export and which may be sites of retention. In this study we investigated which watershed characteristics control N sourcing, biogeochemical processing of nitrate (NO3–) during storms, and the amount of rainfall N that is retained within urban watersheds. We used triple isotopes of NO3– (δ15N, δ18O, and Δ17O) to identify sources and transformations of NO3– during storms from 10 nested arid urban watersheds that variedmore » in stormwater infrastructure type and drainage area. Stormwater infrastructure and land cover—retention basins, pipes, and grass cover—dictated the sourcing of NO3– in runoff. Urban watersheds can be strong sinks or sources of N to stormwater depending on the proportion of rainfall that leaves the watershed as runoff, but we found no evidence that denitrification occurred during storms. Our results suggest that watershed characteristics control the sources and transport of inorganic N in urban stormwater but that retention of inorganic N at the timescale of individual runoff events is controlled by hydrologic, rather than biogeochemical, mechanisms.« less
NASA Astrophysics Data System (ADS)
Jaffe, P. R.; Pennino, M. J.; McDonald, R.
2016-12-01
Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Baltimore County, MD, Montgomery County, MD, and Washington, DC, were selected based on the availability of data on SGI, water quality, and stream flow. The watershed scale impact of SGI was evaluated by assessing how increased spatial density of SGI correlates with stream hydrology and nitrogen exports over space and time. The most common SGI types were detention ponds (58%), followed by marshes (12%), sand filters (9%), wet ponds (7%), infiltration trenches (4%), and rain gardens (2%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI (>10% SGI) have 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff than watersheds with lower SGI. Watersheds with more SGI also show 44% less NO3- and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in combined sewer overflows in watersheds with greater SGI. Based on specific SGI types, infiltration trenches (R2 = 0.35) showed the strongest correlation with hydrologic metrics, likely due to their ability to attenuate flow, while bioretention (R2 = 0.19) and wet ponds (R2 = 0.12) showed stronger relationships with nitrogen compared to other SGI types, possibly due to greater denitrification in these sites. When comparing individual watersheds over time, increases in SGI corresponded to non-significant reductions in hydrologic flashiness and combined sewer overflows compared to watersheds with no change in SGI. This study shows that while implementation of SGI is ongoing, some regions are beginning to have enough SGI to see significant impacts on hydrology and water quality at the watershed scale.
Tracking geomorphic signatures of watershed suburbanization with multi-temporal LiDAR
Jones, Daniel K.; Baker, Matthew E.; Miller, Andrew J.; Jarnagin, S. Taylor; Hogan, Dianna M.
2014-01-01
Urban development practices redistribute surface materials through filling, grading, and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-time comparisons of disparate urban and rural landscapes. However, no previous studies have documented geomorphic changes from development using multiple dates of high-resolution topographic data at the watershed scale. This study utilized a time series of five sequential light detection and ranging (LiDAR) derived digital elevation models (DEMs) to track watershed geomorphic changes within two watersheds throughout development (2002–2008) and across multiple spatial scales (0.01–1 km2). Development-induced changes were compared against an undeveloped forested watershed during the same time period. Changes in elevations, slopes, hypsometry, and surface flow pathways were tracked throughout the development process to assess watershed geomorphic alterations. Results suggest that development produced an increase in sharp topographic breaks between relatively flat surfaces and steep slopes, replacing smoothly varying hillslopes and leading to greater variation in slopes. Examinations of flowpath distributions highlight systematic modifications that favor rapid convergence in unchanneled upland areas. Evidence of channel additions in the form of engineered surface conduits is apparent in comparisons of pre- and post-development stream maps. These results suggest that topographic modification, in addition to impervious surfaces, contributes to altered hydrologic dynamics observed in urban systems. This work highlights important considerations for the use of repeat LiDAR flights in analyzing watershed change through time. Novel methods introduced here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during development and help guide future research directions for development-based watershed studies.
NASA Astrophysics Data System (ADS)
Wang, X.; Liu, T.; Li, R.; Yang, X.; Duan, L.; Luo, Y.
2012-12-01
Wetlands are one of the most important watershed microtopographic features that affect, in combination rather than individually, hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models, such as the Soil and Water Assessment Tool (SWAT), can be a best resort if wetlands can be appropriately represented in the models. However, the exact method that should be used to incorporate wetlands into hydrologic models is the subject of much disagreement in the literature. In addition, there is a serious lack of information about how to model wetland conservation-restoration effects using such kind of integrated modeling approach. The objectives of this study were to: 1) develop a "hydrologic equivalent wetland" (HEW) concept; and 2) demonstrate how to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba of Canada, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota of the United States. The HEWs were defined in terms of six calibrated parameters: the fraction of the subbasin area that drains into wetlands (WET_FR), the volume of water stored in the wetlands when filled to their normal water level (WET_NVOL), the volume of water stored in the wetlands when filled to their maximum water level (WET_MXVOL), the longest tributary channel length in the subbasin (CH_L1), Manning's n value for the tributary channels (CH_N1), and Manning's n value for the main channel (CH_N2). The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes and wetland characteristics (e.g., size and morphology) to be accurately represented in the models. The loss of the first 10 to 20% of the wetlands in the Minnesota study area would drastically increase the peak discharge and loadings of sediment, total phosphorus (TP), and total nitrogen (TN). On the other hand, the justifiable reductions of the peak discharge and loadings of sediment, TP, and TN in the Manitoba study area may require that 50 to 80% of the lost wetlands be restored. Further, the comparison between the predicted restoration and conservation effects revealed that wetland conservation seems to deserve a higher priority while both wetland conservation and restoration may be equally important. Moreover, although SWAT was used in this study, the HEW concept is generic and can also be applied with any other hydrologic models.
NASA Astrophysics Data System (ADS)
Smith, A. A.; Welch, C.; Stadnyk, T. A.
2018-05-01
Evapotranspiration (ET) partitioning is a growing field of research in hydrology due to the significant fraction of watershed water loss it represents. The use of tracer-aided models has improved understanding of watershed processes, and has significant potential for identifying time-variable partitioning of evaporation (E) from ET. A tracer-aided model was used to establish a time-series of E/ET using differences in riverine δ18O and δ2H in four northern Canadian watersheds (lower Nelson River, Manitoba, Canada). On average E/ET follows a parabolic trend ranging from 0.7 in the spring and autumn to 0.15 (three watersheds) and 0.5 (fourth watershed) during the summer growing season. In the fourth watershed wetlands and shrubs dominate land cover. During the summer, E/ET ratios are highest in wetlands for three watersheds (10% higher than unsaturated soil storage), while lowest for the fourth watershed (20% lower than unsaturated soil storage). Uncertainty of the ET partition parameters is strongly influenced by storage volumes, with large storage volumes increasing partition uncertainty. In addition, higher simulated soil moisture increases estimated E/ET. Although unsaturated soil storage accounts for larger surface areas in these watersheds than wetlands, riverine isotopic composition is more strongly affected by E from wetlands. Comparisons of E/ET to measurement-intensive studies in similar ecoregions indicate that the methodology proposed here adequately partitions ET.
NASA Astrophysics Data System (ADS)
Nur Khairiah, Rahmi; Setiawan, Yudi; Budi Prasetyo, Lilik; Ayu Permatasari, Prita
2017-01-01
Ecological functions of agroforestry systems have perceived benefit to people around Cidanau Watershed, especially in the protection of water quality. The main causes of the problems encountered in the Cidanau Watershed are associated with the human factors, especially encroachment and conversion of forest into farmland. The encroachment has made most forest in Cidanau Watershed become bare land. To preserve the ecological function of agroforestry systems in Cidanau Watershed, monitoring of the condition of the vegetation canopy in agroforestry systems is really needed. High intensity thinning of crown density due to deforestation can change stand leaf area index dramatically. By knowing LAI, we can assess the condition of the vegetation canopy in agroforestry systems. LAI in this research was obtained from Hemispherical Photographs analysis using the threshold method in HemiView Canopy Analysis Software. Our research results indicate that there are six types of agroforestry in Cidanau Watershed i.e. Sengon Agroforestry, Clove Agroforestry, Melinjo Agroforestry, Chocolate Agroforestry, Coffee Agroforestry, and Complex Agroforestry. Several factors potentially contribute to variations in the value of LAI in different types of agroforestry. The simple assumptions about differences ranges of LAI values on six types of agroforestry is closely related to leaf area and plant population density.
ERIC Educational Resources Information Center
Haskin, Kathleen M.
A watershed is an area of land where water is drained ultimately to a particular watercourse or body of water. This curriculum guide acts as a comprehensive resource for educators at all levels to explore the many facets of watersheds for New York City. The guide investigates all the dynamics of watershed education, exploring the environmental and…
Clearwater Focus Watershed; Nez Perce Tribe, 2003-2004 Annual Report.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jones, Ira
2004-06-01
The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division, approaches watershed restoration with a goal to protect, restore, and enhance a connected network of functioning habitat types capable of supporting all fish life stages. Its goal is also to re-establish normal patterns of production, dispersal, and exchange of genetic information within the 1855 Treaty Area. The Nez Perce Tribe began watershed restoration projects within the Clearwater River Subbasin in 1996. Progress has been made in restoring the sub-basin by excluding cattle from critical riparian areas through fencing, stabilizing stream banks, decommissioning roads, and upgrading culverts. Coordination of thesemore » projects is critical to the success of the restoration of the sub-basin. Coordination activities also includes: inter and intra-department coordination, sub-basin assessment and planning, involving government and private organizations, and treaty area coordination.« less
Benotti, Mark J.
2008-01-01
The natural resources and watershed conditions of National Park units in the New York-New Jersey area - Gateway National Recreation Area (GATE), Sagamore Hill National Historic Site (SAHI), and Fire Island National Seashore (FIIS) - are threatened by different degrees of urbanization and direct or indirect human use. Such threats as nutrient enrichment, sedimentation, exotic species invasion, water pollution, and development pose serious management concerns for these parks. Limited investigations of the status of different natural resources at or near each park have been conducted, but a comprehensive understanding of the natural resources and watershed conditions at FIIS, GATE, and SAHI is needed. This report details the sources of spatial data and metadata assembled into a Geographic Information System (GIS) for the purpose of assessing natural resources and watershed conditions at GATE, SAHI, and FIIS.
NASA Astrophysics Data System (ADS)
Charnay, Bérengère
2011-07-01
In the last fifty years, many mountain watersheds in temperate countries have known a progressive change from self-standing agro-silvo-pastoral systems to leisure dominated areas characterized by a concentration of tourist accommodations, leading to a drinking water peak during the winter tourist season, when the water level is lowest in rivers and sources. The concentration of water uses increases the pressure on "aquatic habitats" and competition between uses themselves. Consequently, a new concept was developed following the international conferences in Dublin (International Conference on Water and the Environment - ICWE) and Rio de Janeiro (UN Conference on Environment and Development), both in 1992, and was broadly acknowledged through international and European policies. It is the concept of Integrated Water Resource Management ( IWRM). It meets the requirements of different uses of water and aquatic zones whilst preserving the natural functions of such areas and ensuring a satisfactory economic and social development. This paper seeks to evaluate a local water resources management system in order to implement it using IWRM in mountain watersheds. The assessment method is based on the systemic approach to take into account all components influencing a water resources management system at the watershed scale. A geographic information system was built to look into interactions between water resources, land uses, and water uses. This paper deals specifically with a spatial comparison between hydrologically sensitive areas and land uses. The method is applied to a French Alps watershed: the Giffre watershed (a tributary of the Arve in Haute-Savoie). The results emphasize both the needs and the gaps in implementing IWRM in vulnerable mountain regions.
NASA Astrophysics Data System (ADS)
Goodrich, D. C.; Clifford, T. J.; Guertin, D. P.; Sheppard, B. S.; Barlow, J. E.; Korgaonkar, Y.; Burns, I. S.; Unkrich, C. C.
2016-12-01
Wildfires disasters are common throughout the western US. While many feel fire suppression is the largest cost of wildfires, case studies note rehabilitation costs often equal or greatly exceed suppression costs. Using geospatial data sets, and post-fire burn severity products, coupled with the Automated Geospatial Watershed Assessment tool (AGWA - www.tucson.ars.ag.gov/agwa), the Dept. of Interior, Burned Area Emergency Response (BAER) teams can rapidly analyze and identify at-risk areas to target rehabilitation efforts. AGWA employs nationally available geospatial elevation, soils, and land cover data to parameterize the KINEROS2 hydrology and erosion model. A pre-fire watershed simulation can be done prior to BAER deployment using design storms. As soon as the satellite-derived Burned Area Reflectance Classification (BARC) map is obtained, a post-fire watershed simulation using the same storm is conducted. The pre- and post-fire simulations can be spatially differenced in the GIS for rapid identification of high at-risk areas of erosion or flooding. This difference map is used by BAER teams to prioritize field observations and in-turn produce a final burn severity map that is used in AGWA/KINEROS2 simulations to provide report ready results. The 2013 Elk Wildfire Complex that burned over 52,600 ha east of Boise, Idaho provides a tangible example of how BAER experts combined AGWA and geospatial data that resulted in substantial rehabilitation cost savings. The BAER team initially, they identified approximately 6,500 burned ha for rehabilitation. The team then used the AGWA pre- and post-fire watershed simulation results, accessibility constraints, and land slope conditions in an interactive process to locate burned areas that posed the greatest threat to downstream values-at-risk. The group combined the treatable area, field observations, and the spatial results from AGWA to target seed and mulch treatments that most effectively reduced the threats. Using this process, the BAER Team reduced the treatable acres from the original 16,000 ha to between 800 and 1,600 ha depending on the selected alternative. The final awarded contract amounted to about 1,480/ha, therefore, a total savings of 7.2 - $8.4 million was realized for mulch treatment alone.
Habitat change statistics and species-area curves were used to estimate the effects of alternative future scenarios for agriculture on plant diversity in Iowa farmlands. Study areas were two watersheds in central Iowa of about 50 and 90 square kilometers, respectively. Future s...
Spatial connectivity, scaling, and temporal trajectories as emergent urban stormwater impacts
NASA Astrophysics Data System (ADS)
Jovanovic, T.; Gironas, J. A.; Hale, R. L.; Mejia, A.
2016-12-01
Urban watersheds are structurally complex systems comprised of multiple components (e.g., streets, pipes, ponds, vegetated swales, wetlands, riparian corridors, etc.). These multiple engineered components interact in unanticipated and nontrivial ways with topographic conditions, climate variability, land use/land cover changes, and the underlying eco-hydrogeomorphic dynamics. Such interactions can result in emergent urban stormwater impacts with cascading effects that can negatively influence the overall functioning of the urban watershed. For example, the interaction among many detention ponds has been shown, in some situations, to synchronize flow volumes and ultimately lead to downstream flow amplifications and increased pollutant mobilization. Additionally, interactions occur at multiple temporal and spatial scales requiring that urban stormwater dynamics be represented at the long-term temporal (decadal) and across spatial scales (from the single lot to the watershed scale). In this study, we develop and implement an event-based, high-resolution, network hydro-engineering model (NHEM), and demonstrate an approach to reconstruct the long-term regional infrastructure and land use/land cover conditions of an urban watershed. As the study area, we select an urban watershed in the metropolitan area of Scottsdale, Arizona. Using the reconstructed landscapes to drive the NHEM, we find that distinct surficial, hydrologic connectivity patterns result from the intersection of hydrologic processes, infrastructure, and land use/land cover arrangements. These spatial patters, in turn, exhibit scaling characteristics. For example, the scaling of urban watershed dispersion mechanisms shows altered scaling exponents with respect to pre-urban conditions. For example, the scaling exponent associated with geomorphic dispersion tends to increase for urban conditions, reflecting increased surficial path heterogeneity. Both the connectivity and scaling results can be used to delineate impact trajectories (i.e. the evolution of spatially referenced impacts over time). We find that the impact trajectories provide insight about the urban stormwater sustainability of watersheds as well as clues about the potential imprint of socio-environmental feedbacks in the evolutionary dynamics.
Jiang, Rui; Wang, Chun-ying; Hatano, Ryusuke; Kuramochi, Kanta; Hayakawa, Atsushi; Woli, Krishna P
2015-04-01
It is difficult to investigate the factors that control the riverine nitrate-nitrogen (NO3--N) export in a watershed which gains or losses groundwater. To control the NO3--N contamination in these watersheds, it is necessary to investigate the factors that are related to the export of NO3--N that is only produced by the watershed itself. This study was conducted in the Shibetsu watershed located in eastern Hokkaido, Japan, which gains external groundwater contribution (EXT) and 34% of the annual NO3--N loading occurs through EXT. The riverine NO3--N exports from 1980 to 2009 were simulated by the SWAT model, and the factors controlling the temporal and spatial patterns of NO3--N exports were investigated without considering the EXT. The results show that hydrological events control NO3--N export at the seasonal scale, while the hydrological and biogeochemical processes are likely to control NO3--N export at the annual scale. There was an integrated effect among the land use, topography, and soil type related to denitrification process, that regulated the spatial patterns of NO3--N export. The spatial distribution of NO3--N export from hydrologic response units (HRUs) identified the agricultural areas with surplus N that are vulnerable to nitrate contamination. A new standard for the N fertilizer application rate including manure application should be given to control riverine NO3--N export. This study demonstrates that applying the SWAT model is an appropriate method to determine the temporal and spatial patterns of NO3--N export from the watershed which includes EXT and to identify the crucial pollution areas within a watershed in which the management practices can be improved to more effectively control NO3--N export to water bodies.
NASA Astrophysics Data System (ADS)
Molla, Tegegne; Sisheber, Biniam
2017-01-01
Soil erosion is one of the major factors affecting sustainability of agricultural production in Ethiopia. The objective of this paper is to estimate soil erosion using the universal soil loss equation (RUSLE) model and to evaluate soil conservation practices in a data-scarce watershed region. For this purpose, soil data, rainfall, erosion control practices, satellite images and topographic maps were collected to determine the RUSLE factors. In addition, measurements of randomly selected soil and water conservation structures were done at three sub-watersheds (Asanat, Debreyakob and Rim). This study was conducted in Koga watershed at upper part of the Blue Nile basin which is affected by high soil erosion rates. The area is characterized by undulating topography caused by intensive agricultural practices with poor soil conservation practices. The soil loss rates were determined and conservation strategies have been evaluated under different slope classes and land uses. The results showed that the watershed is affected by high soil erosion rates (on average 42 t ha-1 yr-1), greater than the maximum tolerable soil loss (18 t ha-1 yr-1). The highest soil loss (456 t ha-1 yr-1) estimated from the upper watershed occurred on cultivated lands of steep slopes. As a result, soil erosion is mainly aggravated by land-use conflicts and topographic factors and the rugged topographic land forms of the area. The study also demonstrated that the contribution of existing soil conservation structures to erosion control is very small due to incorrect design and poor management. About 35 % out of the existing structures can reduce soil loss significantly since they were constructed correctly. Most of the existing structures were demolished due to the sediment overload, vulnerability to livestock damage and intense rainfall. Therefore, appropriate and standardized soil and water conservation measures for different erosion-prone land uses and land forms need to be implemented in Koga watershed.
Lopez, M.A.; Giovannelli, R.F.
1984-01-01
Rainfall, runoff, and water quality data were collected at nine urban watersheds in the Tampa Bay area from 1975 to 1980. Watershed drainage area ranged from 0.34 to 0.45 sq mi. Land use was mixed. Development ranged from a mostly residential watershed with a 19% impervious surface, to a commercial-residential watershed with a 61% impervious surface. Average biochemical oxygen demand concentrations of base flow at two sites and of stormwater runoff at five sites exceeded treated sewage effluent standards. Average coliform concentrations of stormwater runoff at all sites were several orders of magnitude greater than standards for Florida Class III receiving water (for recreation or propagation and management of fish and wildlife). Average concentrations of lead and zinc in stormwater runoff were consistently higher than Class III standards. Stormwater-runoff loads and base-flow concentrations of biochemical oxygen demand, chemical oxygen demand, total nitrogen, total organic nitrogen, total phosphorus, and lead were related to runoff volume, land use, urban development, and antecedent daily rainfall by multiple linear regression. Stormwater-runoff volume was related to pervious area, hydraulically connected impervious surfaces, storm rainfall, and soil-infiltration index. Base-flow daily discharge was related to drainage area and antecedent daily rainfall. The flow regression equations of this report were used to compute 1979 water-year loads of biochemical oxygen demand, chemical oxygen demand, total nitrogen, total organic nitrogen, total phosphorus , and total lead for the nine Tampa Bay area urban watersheds. (Lantz-PTT)
Foster, Guy M.; Lee, Casey J.; Ziegler, Andrew C.
2012-01-01
The U.S. Geological Survey, in cooperation with the Kansas Water Office, investigated sediment transport to and from three small impoundments (average surface area of 0.1 to 0.8 square miles) in northeast Kansas during March 2009 through September 2011. Streamgages and continuous turbidity sensors were operated upstream and downstream from Atchison County, Banner Creek, and Centralia Lakes to study the effect of varied watershed characteristics and agricultural practices on sediment transport in small watersheds in northeast Kansas. Atchison County Lake is located in a predominantly agricultural basin of row crops, with wide riparian buffers along streams, a substantial amount of tile drainage, and numerous small impoundments (less than 0.05 square miles; hereafter referred to as “ponds”). Banner Creek Lake is a predominantly grassland basin with numerous small ponds located in the watershed, and wide riparian buffers along streams. Centralia Lake is a predominantly agricultural basin of row crops with few ponds, few riparian buffers along streams, and minimal tile drainage. Upstream from Atchison County, Banner Creek, and Centralia Lakes 24, 38, and 32 percent, respectively, of the total load was transported during less than 0.1 percent (approximately 0.9 days) of the time. Despite less streamflow in 2011, larger sediment loads during that year indicate that not all storm events transport the same amount of sediment; larger, extreme storms during the spring may transport much larger sediment loads in small Kansas watersheds. Annual sediment yields were 360, 400, and 970 tons per square mile per year at Atchison County, Banner, and Centralia Lake watersheds, respectively, which were less than estimated yields for this area of Kansas (between 2,000 and 5,000 tons per square mile per year). Although Centralia and Atchison County Lakes had similar percentages of agricultural land use, mean annual sediment yields upstream from Centralia Lake were about 2.7 times those at Atchison County or Banner Creek Lakes. These data indicate larger yields of sediment from watersheds with row crops and those with fewer small ponds, and smaller yields in watersheds which are primarily grassland, or agricultural with substantial tile drainage and riparian buffers along streams. These results also indicated that a cultivated watershed can produce yields similar to those observed under the assumed reference (or natural) condition. Selected small ponds were studied in the Atchison County Lake watershed to characterize the role of small ponds in sediment trapping. Studied ponds trapped about 8 percent of the sediment upstream from the sediment-sampling site. When these results were extrapolated to the other ponds in the watershed, differences in the extent of these ponds was not the primary factor affecting differences in yields among the three watersheds. However, the selected small ponds were both 45 years old at the time of this study, and have reduced capacity because of being filled in with sediments. Additionally, trapping efficiency of these small ponds decreased over five observed storms, indicating that processes that suspended or resuspended sediments in these shallow ponds, such as wind and waves, affected their trapping efficiencies. While small ponds trapped sediments in small storms, they could be a source of sediment in larger or more closely spaced storm events. Channel slope was similar at all three watersheds, 0.40, 0.46, and 0.31 percent at Atchison County, Banner Creek, and Centralia Lake watersheds, respectively. Other factors, such as increased bank and stream erosion, differences in tile drainage, extent of grassland, or riparian buffers, could be the predominant factors affecting sediment yields from these basins. These results show that reference-like sediment yields may be observed in heavily agricultural watersheds through a combination of field-scale management activities and stream channel protection. When computing loads using published erosion rates obtained by single-point survey methodology, streambank contributions from the main stem of Banner Creek are three times more than the sediment load observed by this study at the sediment sampling site at Banner Creek, 2.6 times more than the sediment load observed by this study at the sediment sampling site at Clear Creek (upstream from Atchison County Lake), and are 22 percent of the load observed by this study at the sediment sampling site at Black Vermillion River above Centralia Lake. Comparisons of study sites to similarly sized urban and urbanizing watersheds in Johnson County, Kansas indicated that sediment yields from the Centralia Lake watershed were similar to those in construction-affected watersheds, while much smaller sediment yields in the Atchison County and Banner Creek watersheds were comparable to stable, heavily urbanized watersheds. Comparisons of study sites to larger watersheds upstream from Tuttle Creek Lake indicate the Black Vermillion River watershed continues to have high sediment yields despite 98 percent of sediment from the Centralia watershed (a headwater of the Black Vermillion River) being trapped in Centralia Lake. Estimated trapping efficiencies for the larger watershed lakes indicated that Banner Creek and Centralia Lakes trapped 98 percent of incoming sediment, whereas Atchison County Lake trapped 72 percent of incoming sediment during the 3-year study period.
NASA Technical Reports Server (NTRS)
Townsend, Philip A.; Helmers, David P.; Kingdon, Clayton C.; McNeil, Brenden E.; de Beurs, Kirsten M.; Eshleman, Keith N.
2009-01-01
Surface mining and reclamation is the dominant driver of land cover land use change (LCLUC) in the Central Appalachian Mountain region of the Eastern U.S. Accurate quantification of the extent of mining activities is important for assessing how this LCLUC affects ecosystem services such as aesthetics, biodiversity, and mitigation of flooding.We used Landsat imagery from 1976, 1987, 1999 and 2006 to map the extent of surface mines and mine reclamation for eight large watersheds in the Central Appalachian region of West Virginia, Maryland and Pennsylvania. We employed standard image processing techniques in conjunction with a temporal decision tree and GIS maps of mine permits and wetlands to map active and reclaimed mines and track changes through time. For the entire study area, active surface mine extent was highest in 1976, prior to implementation of the Surface Mine Control and Reclamation Act in 1977, with 1.76% of the study area in active mines, declining to 0.44% in 2006. The most extensively mined watershed, Georges Creek in Maryland, was 5.45% active mines in 1976, declining to 1.83% in 2006. For the entire study area, the area of reclaimed mines increased from 1.35% to 4.99% from 1976 to 2006, and from 4.71% to 15.42% in Georges Creek. Land cover conversion to mines and then reclaimed mines after 1976 was almost exclusively from forest. Accuracy levels for mined and reclaimed cover was above 85% for all time periods, and was generally above 80% for mapping active and reclaimed mines separately, especially for the later time periods in which good accuracy assessment data were available. Among other implications, the mapped patterns of LCLUC are likely to significantly affect watershed hydrology, as mined and reclaimed areas have lower infiltration capacity and thus more rapid runoff than unmined forest watersheds, leading to greater potential for extreme flooding during heavy rainfall events.
Malik, Mohammad Imran; Bhat, M Sultan
2014-12-01
The Himalayan watersheds are susceptible to various forms of degradation due to their sensitive and fragile ecological disposition coupled with increasing anthropogenic disturbances. Owing to the paucity of appropriate technology and financial resources, the prioritization of watersheds has become an inevitable process for effective planning and management of natural resources. Lidder catchment constitutes a segment of the western Himalayas with an area of 1,159.38 km(2). The study is based on integrated analysis of remote sensing, geographic information system, field study, and socioeconomic data. Multicriteria evaluation of geophysical, land-use and land-cover (LULC) change, and socioeconomic indicators is carried out to prioritize watersheds for natural resource conservation and management. Knowledge-based weights and ranks are normalized, and weighted linear combination technique is adopted to determine final priority value. The watersheds are classified into four priority zones (very high priority, high priority, medium priority, and low priority) on the basis of quartiles of the priority value, thus indicating their ecological status in terms of degradation caused by anthropogenic disturbances. The correlation between priority ranks of individual indicators and integrated indicators is drawn. The results reveal that socioeconomic indicators are the most important drivers of LULC change and environmental degradation in the catchment. Moreover, the magnitude and intensity of anthropogenic impact is not uniform in different watersheds of Lidder catchment. Therefore, any conservation and management strategy must be formulated on the basis of watershed prioritization.
NASA Astrophysics Data System (ADS)
Malik, Mohammad Imran; Bhat, M. Sultan
2014-12-01
The Himalayan watersheds are susceptible to various forms of degradation due to their sensitive and fragile ecological disposition coupled with increasing anthropogenic disturbances. Owing to the paucity of appropriate technology and financial resources, the prioritization of watersheds has become an inevitable process for effective planning and management of natural resources. Lidder catchment constitutes a segment of the western Himalayas with an area of 1,159.38 km2. The study is based on integrated analysis of remote sensing, geographic information system, field study, and socioeconomic data. Multicriteria evaluation of geophysical, land-use and land-cover (LULC) change, and socioeconomic indicators is carried out to prioritize watersheds for natural resource conservation and management. Knowledge-based weights and ranks are normalized, and weighted linear combination technique is adopted to determine final priority value. The watersheds are classified into four priority zones (very high priority, high priority, medium priority, and low priority) on the basis of quartiles of the priority value, thus indicating their ecological status in terms of degradation caused by anthropogenic disturbances. The correlation between priority ranks of individual indicators and integrated indicators is drawn. The results reveal that socioeconomic indicators are the most important drivers of LULC change and environmental degradation in the catchment. Moreover, the magnitude and intensity of anthropogenic impact is not uniform in different watersheds of Lidder catchment. Therefore, any conservation and management strategy must be formulated on the basis of watershed prioritization.
Developing a Watershed Challenge
ERIC Educational Resources Information Center
Roman, Harry T.
2010-01-01
This article presents a watershed challenge that gives students an opportunity to investigate the challenge of using a watershed area as a site for development, examining the many aspects of this multifaceted problem. This design challenge could work well in a team-based format, with students taking on specific aspects of the challenges and…
Chris L. Burcher; E.F. Benfield
2006-01-01
We investigated whether suburbanization influenced the physical and biological characteristics of ten 3rd-0r 4th-order streams that drain historically agricultural watersheds in the southern Appalachians near Asheville, North Carolina. Five watersheds had areas of recent suburban development proximal to stream sites, and 5...
Watershed and stormwater managers need modeling tools to evaluate alternative plans for water quality management and flow abatement techniques in urban and developing areas. A watershed-scale, decision-support framework that is based on cost optimization is needed to support gov...
Estimation of shallow ground-water recharge in the Great Lakes basin
Neff, B.P.; Piggott, A.R.; Sheets, R.A.
2006-01-01
This report presents the results of the first known integrated study of long-term average ground-water recharge to shallow aquifers (generally less than 100 feet deep) in the United States and Canada for the Great Lakes, upper St. Lawrence, and Ottawa River Basins. The approach used was consistent throughout the study area and allows direct comparison of recharge rates in disparate parts of the study area. Estimates of recharge are based on base-flow estimates for streams throughout the Great Lakes Basin and the assumption that base flow in a given stream is equal to the amount of shallow ground-water recharge to the surrounding watershed, minus losses to evapotranspiration. Base-flow estimates were developed throughout the study area using a single model based on an empirical relation between measured base-flow characteristics at streamflow-gaging stations and the surficial-geologic materials, which consist of bedrock, coarse-textured deposits, fine-textured deposits, till, and organic matter, in the surrounding surface-water watershed. Model calibration was performed using base-flow index (BFI) estimates for 959 stations in the U.S. and Canada using a combined 28,784 years of daily streamflow record determined using the hydrograph-separation software program PART. Results are presented for watersheds represented by 8-digit hydrologic unit code (HUC, U.S.) and tertiary (Canada) watersheds. Recharge values were lowest (1.6-4.0 inches/year) in the eastern Lower Peninsula of Michigan; southwest of Green Bay, Wisconsin; in northwestern Ohio; and immediately south of the St. Lawrence River northeast of Lake Ontario. Recharge values were highest (12-16.8 inches/year) in snow shadow areas east and southeast of each Great Lake. Further studies of deep aquifer recharge and the temporal variability of recharge would be needed to gain a more complete understanding of ground-water recharge in the Great Lakes Basin.
Studies of future management and policy options based on different assumptions provide a mechanism to examine possible outcomes and especially their likely benefits and consequences. The Northwest Oregon Pilot Study Area encompasses approximately 59,167 km2 and comprises a mixtur...
Todd, M. Jason; Lowrance, R. Richard; Goovaerts, Pierre; Vellidis, George; Pringle, Catherine M.
2010-01-01
Blackwater streams are found throughout the Coastal Plain of the southeastern United States and are characterized by a series of instream floodplain swamps that play a critical role in determining the water quality of these systems. Within the state of Georgia, many of these streams are listed in violation of the state’s dissolved oxygen (DO) standard. Previous work has shown that sediment oxygen demand (SOD) is elevated in instream floodplain swamps and due to these areas of intense oxygen demand, these locations play a major role in determining the oxygen balance of the watershed as a whole. This work also showed SOD rates to be positively correlated with the concentration of total organic carbon. This study builds on previous work by using geostatistics and Sequential Gaussian Simulation to investigate the patchiness and distribution of total organic carbon (TOC) at the reach scale. This was achieved by interpolating TOC observations and simulated SOD rates based on a linear regression. Additionally, this study identifies areas within the stream system prone to high SOD at representative 3rd and 5th order locations. Results show that SOD was spatially correlated with the differences in distribution of TOC at both locations and that these differences in distribution are likely a result of the differing hydrologic regime and watershed position. Mapping of floodplain soils at the watershed scale shows that areas of organic sediment are widespread and become more prevalent in higher order streams. DO dynamics within blackwater systems are a complicated mix of natural and anthropogenic influences, but this paper illustrates the importance of instream swamps in enhancing SOD at the watershed scale. Moreover, our study illustrates the influence of instream swamps on oxygen demand while providing support that many of these systems are naturally low in DO. PMID:20938491
Design Considerations and Economics of Water Harvesting System for Crop Production
NASA Astrophysics Data System (ADS)
Pali, A. K.
2016-06-01
By and large, the design of water harvesting pond is generally based on thumb rules and needs to be upgraded on scientific and engineering principles. In this study, the design procedure of on-farm water harvesting pond has been discussed and two farm ponds of circular, rectangular and square shapes were designed for 50, 60, 75 and 80 % probability of occurrence of rainfall and runoff. Though, the circular shape resulted in the least mean water surface area, but due to not being practicable for agricultural operations, it was discarded. The square shaped ponds resulted in giving least water surface areas as 0.761 ha for the micro watershed of 8.19 ha and as 0.246 ha for the micro watershed of 1.7 ha at 80 % probability level of rainfall and runoff at 80 % level of probability. The storage capacity of the first pond was found as 32,314 m3 and it was 12,962 m3 for the second farm pond. The area to be occupied by the two ponds was worked out as about 11 % of the total land area (8.19 ha) of the first micro watershed and about 18-22 % of the area (1.7 ha) of second micro watershed. Results indicated that the designed size of the first farm pond can be acceptable for construction. The economics of farm pond based agricultural production showed that the highest B/C ratio of 2 and 1.9 were possible for the farm pond designed at 80 and 75 % probability of occurrence of rainfall and runoff respectively.
Sloto, Ronald A.; Stuckey, Marla H.; Hoffman, Scott A.
2017-05-10
The current (2015) streamgage network in Pennsylvania and the Susquehanna River Basin in Pennsylvania and New York was evaluated in order to design a network that would meet the hydrologic needs of many partners and serve a variety of purposes and interests, including estimation of streamflow statistics at ungaged sites. This study was done by the U.S. Geological Survey, in cooperation with the Pennsylvania Department of Environmental Protection and the Susquehanna River Basin Commission. The study area includes the Commonwealth of Pennsylvania and the Susquehanna River Basin in Pennsylvania and New York. For this study, 229 streamgages were identified as reference streamgages that could be used to represent ungaged watersheds. Criteria for a reference streamgage are a minimum of 10 years of continuous record, minimally altered streamflow, and a drainage area less than 1,500 square miles. Some of the reference streamgages have been discontinued but provide historical hydrologic information valuable in the determination of streamflow characteristics of ungaged watersheds. Watersheds in the study area not adequately represented by a reference streamgage were identified by examining a range of basin characteristics, the extent of geographic coverage, and the strength of estimated streamflow correlations between gaged and ungaged sites.Basin characteristics were determined for the reference streamgage watersheds and the 1,662 12-digit hydrologic unit code (HUC12) subwatersheds in Pennsylvania and the Susquehanna River Basin using a geographic information system (GIS) spatial analysis and nationally available GIS datasets. Basin characteristics selected for this study include drainage area, mean basin elevation, mean basin slope, percentage of urbanized area, percentage of forested area, percentage of carbonate bedrock, mean annual precipitation, and soil thickness. A GIS spatial analysis was used to identify HUC12 subwatersheds outside the range of basin characteristics of the reference streamgages. There were 320 HUC12 subwatersheds, or 19 percent of the study area, with basin characteristics outside the range represented by the reference streamgage watersheds.A GIS spatial analysis was used to identify geographic gaps in the streamgage network. For each streamgage, a watershed area, called the gage statistical area (GSA), was delineated. The GSA shows the drainage area within a specific drainage-area ratio of the streamgage for transfer of streamflow statistics from that streamgage to ungaged sites on the valid statistical reach of the GSA for a streamgage. In Pennsylvania, a drainage-area ratio of 0.33–3 times the drainage area of the ungaged site was found to perform as well as, if not better than, more traditional ratios such as 0.5–1.5 (or 2) for transfer of selected streamflow statistics. A total of 1,102 HUC12 subwatersheds, or 66 percent of the study area, are outside the GSA for a reference streamgage.The USGS Baseline Streamflow Estimator (BaSE) program was used to determine how well HUC12 subwatersheds outside the streamgage GSAs are represented by the reference streamgage network in Pennsylvania, based on estimated streamflow correlation. The centroid of each HUC12 subwatershed was run through the BaSE program to determine the reference streamgage with the highest estimated streamflow correlation. There were 929 HUC12 subwatersheds in Pennsylvania, or 56 percent of the State, with an estimated correlation coefficient less than 0.96.The results from the basin characteristic, geographic, and streamflow correlation analyses were combined to identify 1,405 HUC12 subwatersheds in Pennsylvania and the Susquehanna River Basin in Pennsylvania and New York that lack a representative reference, based on at least one identified gap. Of the 1,405 HUC12 subwatersheds, 139 exhibited all three gaps, indicating a 8-percent gap in the reference streamgage network.Streamgages in areas with similar hydrologic characteristics and in close proximity to one another can potentially provide similar information (termed streamgages with high substitution potential). Streamgages were considered to have a high substitution potential with a nearby streamgage(s) if (1) the streamflow correlation coefficient was equal to or greater than 0.96, (2) the streamgages had 10 years of concurrent record, and (3) the streamgages are in the same watershed within the GSA of the streamgage. Seventy-four current (2015) streamgages with high substitution potential with at least one other streamgage were identified in the study area. Although these identified streamgages have a high substitution potential, they provide valuable streamflow information to a stakeholder. Selected primary uses of these streamgages were identified to determine the overall need for an individual streamgage.
Land use change on climate parameters at Samin subwatershed in Central Java, Indonesia
NASA Astrophysics Data System (ADS)
Sutarno; Komariah; Gunawan, T.; Purnomo, D.; Suntoro
2018-03-01
The Samin sub-watershed (SSW) is one of the critical watersheds in Indonesia which need conservation. The identification of land-use/land-cover changes (LUCC) can help in deciding the priority of conservation areas as well as limiting the widespread of critical lands in the watershed, which can contribute to climate change. The purpose of this study is to determine the impact of land use change on climate parameters, i.e. precipitation, air temperature and relative air humidity. The method is by using the descriptive explorative. The study employed Indonesian topographic map and Landsat's imageries of 1996, 2001, 2006, 2011 and 2016. The climate data from 1996 to 2016 were obtained from surroundings weather station. Data were analyzed using Geographic Information System (GIS) and SPSS. The results showed that land use was dominated by rice fields 22,552.83 ha (69.20%), and converted to non-agricultural lands 165.05 hectares/year for the last 20 years. Forest area decreased 65.8 ha/year, and settlement (housing and industrial estates) increased 253.87 ha/year (11.07%). The statistical analysis resulted in a negative relationship between forest area and air temperature and, but no significant correlation with rainfall.
[Quantitative estimation of evapotranspiration from Tahe forest ecosystem, Northeast China].
Qu, Di; Fan, Wen-Yi; Yang, Jin-Ming; Wang, Xu-Peng
2014-06-01
Evapotranspiration (ET) is an important parameter of agriculture, meteorology and hydrology research, and also an important part of the global hydrological cycle. This paper applied the improved DHSVM distributed hydrological model to estimate daily ET of Tahe area in 2007 using leaf area index and other surface data extracted TM remote sensing data, and slope, aspect and other topographic indices obtained by using the digital elevation model. The relationship between daily ET and daily watershed outlet flow was built by the BP neural network, and a water balance equation was established for the studied watershed, together to test the accuracy of the estimation. The results showed that the model could be applied in the study area. The annual total ET of Tahe watershed was 234.01 mm. ET had a significant seasonal variation. The ET had the highest value in summer and the average daily ET value was 1.56 mm. The average daily ET in autumn and spring were 0.30, 0.29 mm, respectively, and winter had the lowest ET value. Land cover type had a great effect on ET value, and the broadleaf forest had a higher ET ability than the mixed forest, followed by the needle leaf forest.
Building multi-country collaboration on watershed ...
Community-based watershed resilience programs that bridge public health and environmental outcomes often require cross-boundary, multi-country collaboration. The CRESSIDA project, led by the Regional Environmental Center for Central and Eastern Europe (REC) and supported by the US Environmental Protection Agency (EPA), forwards a resilience-focused approach for Western Balkan communities in the Drini and Drina river watersheds with the goal of safeguarding public health and the environment. The initial phases of this project give a contextualized example of how to advance resilience-driven environmental health goals in Western Balkan communities, and experience within the region has garnered several theme areas that require focus in order to promote a holistic watershed management program. In this paper, using CRESSIDA as a case study, we show (1) how watershed projects designed with resilience-driven environmental health goals can work in context, (2) provide data surrounding contextualized problems with resilience and suggest tools and strategies for the implementation of projects to address these problems, and (3) explore how cross-boundary foci are central to the success of these approaches in watersheds that comprise several countries. Published in the journal, Reviews on Environmental Health.
Kadlec, Sarah M; Johnson, Rodney D; Mount, David R; Olker, Jennifer H; Borkholder, Brian D; Schoff, Patrick K
2017-12-01
Testicular oocytes (TOs) have been found in black bass (Micropterus spp.) from many locations in North America. The presence of TOs is often assumed to imply exposure to estrogenic endocrine disrupting compounds (EDCs); however, a definitive causal relationship has yet to be established, and TO prevalence is not consistently low in fish from areas lacking evident EDC sources. This might indicate any of a number of situations: 1) unknown or unidentified EDCs or EDC sources, 2) induction of TOs by other stressors, or 3) testicular oocytes occurring spontaneously during normal development. In the present study, we analyzed TO occurrence in smallmouth bass (Micropterus dolomieu) from 8 populations in northeastern Minnesota watersheds with differing degrees of human development and, hence, presumed likelihood of exposure to anthropogenic chemicals. Three watersheds were categorized as moderately developed, based on the presence of municipal wastewater discharges and higher human population density (4-81 per km 2 ), and 5 watersheds were minimally developed, with very low human population density (0-1 per km 2 ) and minimal built environment. Testicular tissues from mature fish were evaluated using a semiquantitative method that estimated TO density, normalized by cross-sectional area. Testicular oocyte prevalence and density among populations from moderately developed watersheds was higher than in populations from minimally developed watersheds. However, TO prevalence was unexpectedly high and variable (7-43%) in some populations from minimally developed watersheds, and only weak evidence was found for a relationship between TO density and watershed development, suggesting alternative or more complex explanations for TO presence in smallmouth bass from this region. Environ Toxicol Chem 2017;36:3424-3435. © 2017 SETAC. © 2017 SETAC.
He, Zhi Chao; Huang, Shuo; Guo, Qing Hai; Xiao, Li Shan; Yang, De Wei; Wang, Ying; Yang, Yi Fu
2016-08-01
Urban sprawl has impacted increasingly on water environment quality in watersheds. Based on water environmental response, the simulation and prediction of expanding threshold of urban building land could provide an alternative reference for urban construction planning. Taking three watersheds (i.e., Yundang Lake at complete urbanization phase, Maluan Bay at peri-urbanization phase and Xinglin Bay at early urbanization phase) with 2009-2012 observation data as example, we calculated the upper limit of TN and TP capacity in three watersheds and identified the threshold value of urban building land in watersheds using the regional nutrient management (ReNuMa) model, and also predicted the water environmental effects associated with the changes of urban landscape pattern. Results indicated that the upper limit value of TN was 12900, 42800 and 43120 kg, while that of TP was 340, 420 and 450 kg for Yundang, Maluan and Xinglin watershed, respectively. In reality, the environment capacity of pollutants in Yundang Lake was not yet satura-ted, and annual pollutant loads in Maluan Bay and Xinglin Bay were close to the upper limit. How-ever, an obvious upward trend of annual TN and TP loads was observed in Xinglin Bay. The annual pollutant load was not beyond the annual upper limit in three watersheds under Scenario 1, while performed oppositely under Scenario 3. Under Scenario 2, the annual pollutant load in Yundang Lake was under-saturation, and the TN and TP in Maluan Bay were over their limits. The area thresholds of urban building land were 1320, 5600 and 4750 hm 2 in Yundang Lake, Maluan Bay and Xinglin Bay, respectively. This study could benefit the regulation on urban landscape planning.
NASA Astrophysics Data System (ADS)
Li, Zhenwei; Xu, Xianli; Xu, Chaohao; Liu, Meixian; Wang, Kelin
2018-03-01
Southwest China, as one of the largest continuous karst areas in the world, is a severely eroded region due to its special geological condition. Thus, soil and water conservation measures such as dam construction have been extensively implemented in this region to control sediment delivery. However, it remains unclear how dam construction affects multiscale variability of sediment discharge (SD) and its potentially influential factors in southwest China. To assess this, annual SD, water discharge (WD), precipitation (PT), potential evapotranspiration (PET), and normalized differential vegetation index (NDVI) data from 1955 to 2015 were obtained from two karst watersheds of Liujiang (no large dams) and Hongshui (dam-controlled). These sites shared the similar climatic conditions. The Mann-Kendal test, Wilcoxon rank-sum test, and continuous wavelet transform analysis was used to detect the trends and periodicity in SD, and wavelet coherence analysis were employed to detect the temporal covariance between SD and WD, PT, PET, and NDVI. Results indicated that the multiscale variability of SD was strongly influenced by dam construction. The annual SD showed significant 4-year periodic oscillation in the Liujiang watershed, while no significant cycles were found in the Hongshui watershed. Dam construction exerted substantial influence on the multiscale correlations between SD and its associated factors. The time scales that the NDVI resonated with SD were concentrated on the periodicity of 2- and 3-year in the Liujiang watershed. In contrast, no significant periodicities were observed in the Hongshu watershed. This study yields a greater understanding of SD dynamics, and is helpful for better watershed management in karst areas of southwest China.
NASA Astrophysics Data System (ADS)
Saghafian, B.; Mohammadi, A.
2003-04-01
Most studies involving water resources allocation, water quality, hydropower generation, and allowable water withdrawal and transfer require estimation of low flows. Normally, frequency analysis on at-station D-day low flow data is performed to derive various T-yr return period values. However, this analysis is restricted to the location of hydrometric stations where the flow discharge is measured. Regional analysis is therefore conducted to relate the at-station low flow quantiles to watershed characteristics. This enables the transposition of low flow quantiles to ungauged sites. Nevertheless, a procedure to map the regional regression relations for the entire stream network, within the bounds of the relations, is particularly helpful when one studies and weighs alternative sites for certain water resources project. In this study, we used a GIS-aided procedure for low flow mapping in Gilan province, part of northern region in Iran. Gilan enjoys a humid climate with an average of 1100 mm annual precipitation. Although rich in water resources, the highly populated area is quite dependent on minimum amount of water to sustain the vast rice farming and to maintain required flow discharge for quality purposes. To carry out the low flow analysis, a total of 36 hydrometric stations with sufficient and reliable discharge data were identified in the region. The average area of the watersheds was 250 sq. km. Log Pearson type 3 was found the best distribution for flow durations over 60 days, while log normal fitted well the shorter duration series. Low flows with return periods of 2, 5, 10, 25, 50, and 100 year were then computed. Cluster analysis identified two homogeneous areas. Although various watershed parameters were examined in factor analysis, the results showed watershed area, length of the main stream, and annual precipitation were the most effective low flow parameters. The regression equations were then mapped with the aid of GIS based on flow accumulation maps and the corresponding spatially averaged values of other parameters over the upslope area of all stream pixels exceeding a certain threshold area. Such map clearly shows the spatial variation of low flow quantiles along the stream network and enables the study of low flow profiles along any stream.
NASA Astrophysics Data System (ADS)
Galster, J. C.; Pazzaglia, F. J.; Germanoski, D.
2007-12-01
Land use in a watershed exerts a strong influence on trunk channel form and process. Land use changes act over human time scales which is short enough to measure their effects directly using historic aerial photographs. We show that high-resolution topographic surveys comparing channel form for paired watersheds in the Lehigh Valley, PA are indistinguishable, but have channel widths that have changed dramatically in the past five decades. The two watersheds, Little Lehigh Creek and Sacony Creek, are similar in all respects except they have different amount of urban land use. Aerial photographs of the urbanized Little Lehigh Creek show that a majority of the measured widths (67 of 85) were statistically wider in 1999 than in 1947. In contrast, the measured widths from the agricultural Sacony Creek are more evenly distributed among those that widened (18), narrowed (28), and those that were statistically unchanged (6) from 1946 to 1999. From 1946 to 1999 the only section of Sacony creek that widened was that reach downstream of the only sizable urban area in the watershed. The current land use in Sacony Creek watershed resembles that of 1946, while the Little Lehigh Creek watershed has more than tripled its urban area. These data suggest that the increase in urban areas that subsequently increases peak discharges is the mechanism behind the widening that occurred in the Little Lehigh Creek. These wider channels can affect water quality, aquatic habitat, suspended sediment loads, and river aesthetics.
Drainage basin control of acid loadings to two Adirondack lakes
NASA Astrophysics Data System (ADS)
Booty, W. G.; Depinto, J. V.; Scheffe, R. D.
1988-07-01
Two adjacent Adirondack Park (New York) calibrated watersheds (Woods Lake and Cranberry Pond), which receive identical atmospheric inputs, generate significantly different unit area of watershed loading rates of acidity to their respective lakes. A watershed acidification model is used to evaluate the watershed parameters which are responsible for the observed differences in acid loadings to the lakes. The greater overall mean depth of overburden on Woods Lake watershed, which supplies a greater buffer capacity as well as a longer retention time of groundwater, appears to be the major factor responsible for the differences.
NASA Astrophysics Data System (ADS)
Lyon, Steve W.; Walter, M. Todd; Gérard-Marchant, Pierre; Steenhuis, Tammo S.
2004-10-01
Because the traditional Soil Conservation Service curve-number (SCS-CN) approach continues to be used ubiquitously in water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed and tested a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Predicting the location of source areas is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point-source pollution. The method presented here used the traditional SCS-CN approach to predict runoff volume and spatial extent of saturated areas and a topographic index, like that used in TOPMODEL, to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was applied to two subwatersheds of the Delaware basin in the Catskill Mountains region of New York State and one watershed in south-eastern Australia to produce runoff-probability maps. Observed saturated area locations in the watersheds agreed with the distributed CN-VSA method. Results showed good agreement with those obtained from the previously validated soil moisture routing (SMR) model. When compared with the traditional SCS-CN method, the distributed CN-VSA method predicted a similar total volume of runoff, but vastly different locations of runoff generation. Thus, the distributed CN-VSA approach provides a physically based method that is simple enough to be incorporated into water quality models, and other tools that currently use the traditional SCS-CN method, while still adhering to the principles of VSA hydrology.
Gerald J. Gottfried; Peter F. Ffolliott; Daniel G. Neary
2013-01-01
Private and public land managers are attempting to reintroduce fire into the ecosystems of the Peloncillo Mountains to reduce the density of woody species, increase the herbaceous plant cover, and improve the areaâs ecological diversity. The Cascabel Watershed Study, which includes 12 small gauged watersheds, was started in 2000 to evaluate the impacts of cool-season (...
Climate and land use change in an Andean watershed: An NDVI analysis for the years 1985 to 2010
NASA Astrophysics Data System (ADS)
Mazzarino, M.; Finn, J.
2013-12-01
We perform a Landsat 5-TM derived Normalized Difference Vegetation Index (NDVI) analysis in a watershed (approximately 2700 km2) in southern Peru for the years 1985 through 2010. There in the Andes the livelihoods of the predominately Quechua speaking agro-pastoralists depend on access to natural resources. Vegetation within high-elevation wetlands, locally known as bofedales, is a critical resource that sustains herds of alpaca, sheep, and cattle especially during dry season months (June through August) and in drought. The watershed experiences high inter-annual variability in precipitation (attributed to the El Niño Southern Oscillation) and there are documented increases in air temperature and glacier retreat throughout the Andes. Using one dry-season scene per year for 20 of the 26 years from 1985 to 2010, we calculated NDVI for each pixel in the watershed and used these calculations to perform three objectives. First, we calculated mean NDVI for the Nuñoa watershed for each dry season scene. Using this annual watershed averaged NDVI as the response variable we performed a multiple linear regression with the covariates year, precipitation, and temperature in order to determine the relationship between the response and explanatory variables and if there is a trend in mean watershed dry-season NDVI from 1985 to 2010. Second, we delineated the wetlands (bofedales) based on a threshold value applied to the 26 year dry-season mean NDVI for each pixel in the watershed. Third, we performed a multiple linear regression for each pixel in the watershed (3,070,160) using cell specific annual dry-season NDVI as the response variable (n=20) and year, regional precipitation, and regional temperature indices as the predictor variables in order to review the spatial nature of NDVI changes in vegetation in the watershed throughout time (1985-2010), particularly with respect to bofedales. The results of these analyses indicate that there is reduced variability in dry season NDVI and a general increase in NDVI values in the watershed with time. Variability in mean dry season NDVI is highly correlated with wet season (DJFM) precipitation (R2 = 0.77, p-value < 0.05) and this relationship may explain much of the shift in NDVI values however; the increasing trend in NDVI in the watershed is not explained by a trend in precipitation. We were not able to determine a relationship between NDVI and temperature with our methods. And while an increase in dry-season NDVI is seen in the majority of the vegetated pixels (81%) throughout the watershed, approximately 30% of the wetland areas display a decrease in NDVI over the time period. Contemporary socio-political factors and resulting changes in land management and production systems in the region may be resulting in more intensive use of wetland areas, thereby causing the decreasing vegetation trends seen there. These factors, together with potential reductions in glacier melt from several small ice-capped mountains in the north of the study area may all be contributing to the spatial and temporal changes in NDVI seen in the watershed.
NASA Astrophysics Data System (ADS)
Kagoya, Sarah; Paudel, Krishna P.; Daniel, Nadhomi L.
2018-02-01
Soil and water conservation technologies have been widely available in most parts of Uganda. However, not only has the adoption rate been low but also many farmers seem not to be aware of these technologies. This study aims at identifying the factors that influence awareness and adoption of soil and water conservation technologies in Nabajuzi watershed in central Uganda. A bivariate probit model was used to examine farmers' awareness and adoption of soil and water conservation technologies in the watershed. We use data collected from the interview of 400 households located in the watershed to understand the factors affecting the awareness and adoption of these technologies in the study area. Findings indicate that the likelihood of being aware and adopting the technologies are explained by the age of household head, being a tenant, and number of years of access to farmland. To increase awareness and adoption of technologies in Uganda, policymakers may expedite the process of land titling as farmers may feel secure about landholding and thus adopt these technologies to increase profitability and productivity in the long run. Incentive payments to farmers residing in the vulnerable region to adopt these considered technologies may help to alleviate soil deterioration problems in the affected area.
Kagoya, Sarah; Paudel, Krishna P; Daniel, Nadhomi L
2018-02-01
Soil and water conservation technologies have been widely available in most parts of Uganda. However, not only has the adoption rate been low but also many farmers seem not to be aware of these technologies. This study aims at identifying the factors that influence awareness and adoption of soil and water conservation technologies in Nabajuzi watershed in central Uganda. A bivariate probit model was used to examine farmers' awareness and adoption of soil and water conservation technologies in the watershed. We use data collected from the interview of 400 households located in the watershed to understand the factors affecting the awareness and adoption of these technologies in the study area. Findings indicate that the likelihood of being aware and adopting the technologies are explained by the age of household head, being a tenant, and number of years of access to farmland. To increase awareness and adoption of technologies in Uganda, policymakers may expedite the process of land titling as farmers may feel secure about landholding and thus adopt these technologies to increase profitability and productivity in the long run. Incentive payments to farmers residing in the vulnerable region to adopt these considered technologies may help to alleviate soil deterioration problems in the affected area.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Love, E.; Hammack, R.W.; Harbert, W.P.
2005-11-01
The Kettle Creek watershed contains 50–100-year-old surface and underground coal mines that are a continuing source of acid mine drainage (AMD). To characterize the mining-altered hydrology of this watershed, an airborne reconnaissance was conducted in 2002 using airborne thermal infrared imagery (TIR) and helicopter-mounted electromagnetic (HEM) surveys. TIR uses the temperature differential between surface water and groundwater to locate areas where groundwater emerges at the surface. TIR anomalies located in the survey included seeps and springs, as well as mine discharges. In a follow-up ground investigation, hand-held GPS units were used to locate 103 of the TIR anomalies. Of themore » sites investigated, 26 correlated with known mine discharges, whereas 27 were previously unknown. Seven known mine discharges previously obscured from TIR imagery were documented. HEM surveys were used to delineate the groundwater table and also to locate mine pools, mine discharges, and groundwater recharge zones. These surveys located 12 source regions and flow paths for acidic, metal-containing (conductive) mine drainage; areas containing acid-generating mine spoil; and areas of groundwater recharge and discharge, as well as identifying potential mine discharges previously obscured from TIR imagery by nondeciduous vegetation. Follow-up ground-based electromagnetic surveys verified the results of the HEM survey. Our study suggests that airborne reconnaissance can make the remediation of large watersheds more efficient by focusing expensive ground surveys on small target areas.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Love, E.; Hammack, R.; Harbert, W.
2005-12-01
The Kettle Creek watershed contains 50-100-year-old surface and underground coal mines that are a continuing source of acid mine drainage (AMD). To characterize the mining-altered hydrology of this watershed, an airborne reconnaissance was conducted in 2002 using airborne thermal infrared imagery (TIR) and helicopter-mounted electromagnetic (HEM) surveys. TIR uses the temperature differential between surface water and groundwater to locate areas where groundwater emerges at the surface. TIR anomalies located in the survey included seeps and springs, as well as mine discharges. In a follow-up ground investigation, hand-held GPS units were used to locate 103 of the TIR anomalies. Of themore » sites investigated, 26 correlated with known mine discharges, whereas 27 were previously unknown. Seven known mine discharges previously obscured from TIR imagery were documented. HEM surveys were used to delineate the groundwater table and also to locate mine pools, mine discharges, and groundwater recharge zones. These surveys located 12 source regions and flow paths for acidic, metal-containing (conductive) mine drainage; areas containing acid-generating mine spoil; and areas of groundwater recharge and discharge, as well as identifying potential mine discharges previously obscured from TIR imagery by nondeciduous vegetation. Follow-up ground-based electromagnetic surveys verified the results of the HEM survey. Our study suggests that airborne reconnaissance can make the remediation of large watersheds more efficient by focusing expensive ground surveys on small target areas.« less
Improving southwestern riparian areas through watershed management
Leonard F. DeBano; Larry J. Schmidt
1989-01-01
This paper reviews opportunities and watershed restoration techniques available for rehabilitating and enhancing riparian ecosystems in southwest environments. As such, it is intended to serve as a state-of-the-art report on riparian hydrology and improvement in both naturally occurring and man-made riparian areas throughout the Southwest.
Freshwater resources in the Hoosier-Shawnee ecological assessment area
Matt R. Whiles; James E. Garvey
2004-01-01
The Hoosier-Shawnee Ecological Assessment Area contains 40 major watersheds with unique hydrological, ecological, and socioeconomic features. Depending on the watershed, major groundwater resources are a combination of sandstone, carbonate, and semiconsolidated or unconsolidated sand/gravel aquifers. Approximately 69,000 miles of streams flow through the assessment...
Effects of mountain agriculture on nutrient cycling at upstream watersheds
NASA Astrophysics Data System (ADS)
Lin, T.-C.; Shaner, P. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.
2015-05-01
The expansion of agriculture to rugged mountains can exacerbate negative impacts of agriculture activities on ecosystem function. In this study, we monitored streamwater chemistry of four watersheds with varying proportions of agricultural lands (0.4, 3, 17, 22%) and rainfall chemistry of two of the four watersheds at Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportions of agricultural lands, the higher the ion concentrations, which is evident for fertilizer-associated ions (NO3-, K+) but not for ions that are rich in soils (SO42-, Ca2+, Mg2+), suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. The watershed with the highest proportion of agricultural lands had higher concentrations of ions in rainfall and lower nutrient retention capacity (i.e. higher output-input ratio of ions) compared to the relatively pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. Furthermore, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater by more than 70%, indicating that specific landscape configurations help mitigate nutrient enrichment to aquatic systems. We estimated that agricultural lands at our study site contributed approximately 400 kg ha-1 yr-1 of NO3-N and 260 kg ha-1 yr-1 of PO4-P output via streamwater, an order of magnitude greater than previously reported around the globe and can only be matched by areas under intense fertilizer use. Furthermore, we re-constructed watershed nutrient fluxes to show that excessive leaching of N and P, and additional loss of N to the atmosphere via volatilization and denitrification, can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of agriculture activities, especially excessive fertilization, on ecosystem nutrient cycling at mountain watersheds.
Tillery, Anne C.; Haas, Jessica R.
2016-08-11
Wildfire can substantially increase the probability of debris flows, a potentially hazardous and destructive form of mass wasting, in landscapes that have otherwise been stable throughout recent history. Although the exact location, extent, and severity of wildfire or subsequent rainfall intensity and duration cannot be known, probabilities of fire and debris‑flow occurrence for given locations can be estimated with geospatial analysis and modeling. The purpose of this report is to provide information on which watersheds might constitute the most serious potential debris-flow hazards in the event of a large-scale wildfire and subsequent rainfall in the Jemez Mountains. Potential probabilities and estimated volumes of postwildfire debris flows in both the unburned and previously burned areas of the Jemez Mountains and surrounding areas were estimated using empirical debris-flow models developed by the U.S. Geological Survey in combination with fire behavior and burn probability models developed by the U.S. Forest Service.Of the 4,998 subbasins modeled for this study, computed debris-flow probabilities in 671 subbasins were greater than 80 percent in response to the 100-year recurrence interval, 30-minute duration rainfall event. These subbasins ranged in size from 0.01 to 6.57 square kilometers (km2), with an average area of 0.29 km2, and were mostly steep, upstream tributaries to larger channels in the area. Modeled debris-flow volumes in 465 subbasins were greater than 10,000 cubic meters (m3), and 14 of those subbasins had modeled debris‑flow volumes greater than 100,000 m3.The rankings of integrated relative debris-flow hazard indexes for each subbasin were generated by multiplying the individual subbasin values for debris-flow volume, debris‑flow probability, and average burn probability. The subbasins with integrated hazard index values in the top 2 percent typically are large, upland tributaries to canyons and channels primarily in the Upper Rio Grande and Rio Grande-Santa Fe watershed areas. No subbasins in this group have basin areas less than 1.0 km2. Many of these areas already had significant mass‑wasting episodes following the Las Conchas Fire in 2011. Other subbasins with integrated hazard index values in the top 2 percent are scattered throughout the Jemez River watershed area, including some subbasins in the interior of the Valles Caldera. Only a few subbasins in the top integrated hazard index group are in the Rio Chama watershed area.This prewildfire assessment approach is valuable to resource managers because the analysis of the debris-flow threat is made before a wildfire occurs, which facilitates prewildfire management, planning, and mitigation. In north‑central New Mexico, widespread watershed restoration efforts are being done to safeguard vital watersheds against the threat of catastrophic wildfire. This study was designed to help select ideal locations for the restoration efforts that could have the best return on investment.
Qian, S.S.; Anderson, Chauncey W.
1999-01-01
We analyzed available concentration data of five commonly used herbicides and three pesticides collected from small streams in the Willamette River Basin in Oregon to identify factors that affect the variation of their concentrations in the area. The emphasis of this paper is the innovative use of classification and regression tree models for exploratory data analysis as well as analyzing data with a substantial amount of left-censored values. Among variables included in this analysis, land-use pattern in the watershed is the most important for all but one (simazine) of the eight pesticides studied, followed by geographic location, intensity of agriculture activities in the watershed (represented by nutrient concentrations in the stream), and the size of the watershed. The significant difference between urban sites and agriculture sites is the variability of stream concentrations. While all 16 nonurban watersheds have significantly higher variation than urban sites, the same is not necessarily true for the mean concentrations. Seasonal variation accounts for only a small fraction of the total variance in all eight pesticides.We analyzed available concentration data of five commonly used herbicides and three pesticides collected from small streams in the Willamette River Basin in Oregon to identify factors that affect the variation of their concentrations in the area. The emphasis of this paper is the innovative use of classification and regression tree models for exploratory data analysis as well as analyzing data with a substantial amount of left-censored values. Among variables included in this analysis, land-use pattern in the watershed is the most important for all but one (simazine) of the eight pesticides studied, followed by geographic location, intensity of agriculture activities in the watershed (represented by nutrient concentrations in the stream), and the size of the watershed. The significant difference between urban sites and agriculture sites is the variability of stream concentrations. While all 16 nonurban watersheds have significantly higher variation than urban sites, the same is not necessarily true for the mean concentrations. Seasonal variation accounts for only a small fraction of the total variance in all eight pesticides.
Clarke, John S.; Williams, Lester J.
2010-01-01
Hydrologic studies conducted during 2003-2008 as part of the U.S. Geological Survey Cooperative Water Program with the City of Lawrenceville, Georgia, provide important data for the management of water resources. The Cooperative Water Program includes (1) hydrologic monitoring (precipitation, streamflow, and groundwater levels) to quantify baseline conditions in anticipation of expanded groundwater development, (2) surface-water-quality monitoring to provide an understanding of how stream quality is affected by natural (such as precipitation) and anthropogenic factors (such as impervious area), and (3) geologic studies to better understand groundwater flow and hydrologic processes in a crystalline rock setting. The hydrologic monitoring network includes each of the two watersheds projected for groundwater development?the Redland-Pew Creek and upper Alcovy River watersheds?and the upper Apalachee River watershed, which serves as a background or control watershed because of its similar hydrologic and geologic characteristics to the other two watersheds. In each watershed, precipitation was generally greater during 2003-2005 than during 2006-2008, and correspondingly streamflow and groundwater levels decreased. In the upper Alcovy River and Redland-Pew Creek watersheds, groundwater level declines during 2003-2008 were mostly between 2 and 7 feet, with maximum observed declines of as much as 28.5 feet in the upper Alcovy River watershed, and 49.1 feet in the Redland-Pew Creek watershed. Synoptic base-flow measurements were used to locate and quantify gains or losses to streamflow resulting from groundwater interaction (groundwater seepage). In September 2006, seepage gains were measured at five of nine reaches evaluated in the upper Alcovy River watershed, with losses in the other four. The four losing reaches were near the confluence of the Alcovy River and Cedar Creek where the stream gradient is low and bedrock is at or near the land surface. In the Redland-Pew Creek watershed, groundwater seepage gains were observed at each of the 10 reaches measured during September 2008. Continuous specific conductance, temperature, and turbidity data were collected at gage sites located on Pew and Shoal Creeks, which drain about 32 percent of the city area, and at a background site on the Apalachee River located outside the city boundary. Continuous surface-water monitoring data indicate that reduced precipitation during 2006-2008 resulted in lower turbidity and higher stream temperature and specific conductance than in 2003-2005. In comparison to the other two stream sites, water at the Apalachee River site had the lowest mean and median values for specific conductance, and the greatest mean and median values for turbidity during October 2005-December 2008. In addition to continuous water-quality monitoring, samples were collected periodically to determine fecal-coliform bacteria concentrations. None of the individual samples at the three sites exceeded the Georgia Environmental Protection Division (GaEPD) limit of 4,000 most probable number of colonies per 100 milliliters (MPN col/100 mL) for November through April. In the Redland-Pew Creek and Shoal Creek watersheds, the GaEPD 30-day geometric mean standard of 200 MPN col/100 mL for May-October was exceeded twice during two sampling periods in May-October 2007 and twice during two sampling periods in May-October 2008. Groundwater studies conducted during 2003-2007 include the collection of borehole geophysical logs from four test wells drilled in the upper Alcovy River watershed to provide insight into subsurface geologic characteristics. A flowmeter survey was conducted in a well south of Rhodes Jordan Park to help assess the interconnection of the well with surface water and the effectiveness of a liner-packer assembly installed to eliminate that interconnection. At that same well, hydraulic packer tests were conducted in the open-hole section of the well, and water samp
Smith, Kathleen S.
2005-01-01
This work evaluates the use of the biotic ligand model (BLM), an aquatic toxicity model, to predict toxic effects of metals on aquatic biota in areas underlain by different rock types. The chemical composition of water, soil, and sediment is largely derived from the composition of the underlying rock. Geologic source materials control key attributes of water chemistry that affect metal toxicity to aquatic biota, including: 1) potentially toxic elements, 2) alkalinity, 3) total dissolved solids, and 4) soluble major elements, such as Ca and Mg, which contribute to water hardness. Miller (2002) compiled chemical data for water samples collected in watersheds underlain by ten different rock types, and in a mineralized area in western Colorado. He found that each rock type has a unique range of water chemistry. In this study, the ten rock types were grouped into two general categories, igneous and sedimentary. Water collected in watersheds underlain by sedimentary rock has higher mean pH, alkalinity, and calcium concentrations than water collected in watersheds underlain by igneous rock. Water collected in the mineralized area had elevated concentrations of calcium and sulfate in addition to other chemical constituents. Miller's water-chemistry data were used in the BLM (computer program) to determine copper and zinc toxicity to Daphnia magna. Modeling results show that waters from watersheds underlain by different rock types have characteristic ranges of predicted LC 50 values (a measurement of aquatic toxicity) for copper and zinc, with watersheds underlain by igneous rock having lower predicted LC 50 values than watersheds underlain by sedimentary rock. Lower predicted LC 50 values suggest that aquatic biota in watersheds underlain by igneous rock may be more vulnerable to copper and zinc inputs than aquatic biota in watersheds underlain by sedimentary rock. For both copper and zinc, there is a trend of increasing predicted LC 50 values with increasing dissolved organic carbon (DOC) concentrations. Predicted copper LC 50 values are extremely sensitive to DOC concentrations, whereas alkalinity appears to have an influence on zinc toxicity at alkalinities in excess of about 100 mg/L CaCO 3 . These findings show promise for coupling the BLM (computer program) with measured water-chemistry data to predict metal toxicity to aquatic biota in different geologic settings and under different scenarios. This approach may ultimately be a useful tool for mine-site planning, mitigation and remediation strategies, and ecological risk assessment.
Dissolved organic carbon export and internal cycling in small, headwater lakes
Stets, Edward G.; Striegl, Robert G.; Aiken, George R.
2010-01-01
Carbon (C) cycling in freshwater lakes is intense but poorly integrated into our current understanding of overall C transport from the land to the oceans. We quantified dissolved organic carbon export (DOCX) and compared it with modeled gross DOC mineralization (DOCR) to determine whether hydrologic or within-lake processes dominated DOC cycling in a small headwaters watershed in Minnesota, USA. We also used DOC optical properties to gather information about DOC sources. We then compared our results to a data set of approximately 1500 lakes in the Eastern USA (Eastern Lake Survey, ELS, data set) to place our results in context of lakes more broadly. In the open-basin lakes in our watershed (n = 5), DOCX ranged from 60 to 183 g C m−2 lake area yr−1, whereas DOCR ranged from 15 to 21 g C m−2 lake area yr−1, emphasizing that lateral DOC fluxes dominated. DOCX calculated in our study watershed clustered near the 75th percentile of open-basin lakes in the ELS data set, suggesting that these results were not unusual. In contrast, DOCX in closed-basin lakes (n = 2) was approximately 5 g C m−2 lake area yr−1, whereas DOCR was 37 to 42 g C m−2 lake area yr−1, suggesting that internal C cycling dominated. In the ELS data set, median DOCX was 32 and 12 g C m−2 yr−1 in open-basin and closed-basin lakes, respectively. Although not as high as what was observed in our study watershed, DOCX is an important component of lake C flux more generally, particularly in open-basin lakes.
Falcone, James A.; Stewart, Jana; Sobieszczyk, Steven; Dupree, Jean; McMahon, Gerard; Buell, Gary
2007-01-01
As part of the U.S. Geological Survey National Water-Quality Assessment Program, the effects of urbanization on stream ecosystems have been intensively investigated in six metropolitan areas in the United States. Approximately 30 watersheds in each area, ranging in size from 4 to 560 square kilometers (median is 50 square kilometers), and spanning a development gradient from very low to very high urbanization, were examined near Atlanta, Georgia; Raleigh, North Carolina; Denver, Colorado; Dallas-Fort Worth, Texas; Portland, Oregon; and Milwaukee-Green Bay, Wisconsin. These six studies are a continuation of three previous studies in Boston, Massachusetts; Birmingham, Alabama; and Salt Lake City, Utah. In each study, geographic information system data for approximately 300 variables were assembled to (a) characterize the environmental settings of the areas and (b) establish a consistent multimetric urban intensity index based on locally important land-cover, infrastructure, and socioeconomic variables. This paper describes the key features of urbanization and the urban intensity index for the study watersheds within each area, how they differ across study areas, and the relation between the environmental setting and the characteristics of urbanization. A number of features of urbanization were identified that correlated very strongly to population density in every study area. Of these, road density had the least variability across diverse geographic settings and most closely matched the multimetric nature of the urban intensity index. A common urban intensity index was derived that ranks watersheds across all six study areas. Differences in local natural settings and urban geography were challenging in (a) identifying consistent urban gradients in individual study areas and (b) creating a common urban intensity index that matched the site scores of the local urban intensity index in all areas. It is intended that the descriptions of the similarities and differences in urbanization and environmental settings across these study areas will provide a foundation for understanding and interpreting the effects of urbanization on stream ecosystems in the studies being conducted as part of the National Water-Quality Assessment Program.
NASA Astrophysics Data System (ADS)
Zhang, Yuhu; Yu, Changqing; Qi, Jiaguo; Zhang, Zili; Shi, Qinshan
2007-11-01
The problem of efficient use of multi-temporal remotely sensed data for land-cover and landscape pattern dynamics has already considerable attention in landscape ecology and some other disciplines. This research develops and tests a methodological approach to monitor and analysis landscape dynamics change of Yongding river watershed (Mentougou section) as study area from 1988 to 2005, The result shows that the OIF is the best method of optimal bands selection in Landsat TM remote sensing data, TM3, 4, 5 bands is optimal band combination ;the Mentougou Reach of Yongding river watershed landscape changed significantly in terms of its composition over the period 1988-2005, The total landscape patches of study area in 2005 are more those in 1988,2001, Mean patch size(MPS)decreased sharply, Number of patches(NP) increased sharply, The landscape pattern takes on the fragmentation trends under the effect on the human activity. The forest (woodland and shrubland)are the main landscape matrix. with a significant decrease in croplands and a increase in built-up (residential, urban land) and industrial minerals mining land(coal, open-pit)over the 17 years, And the underlying socio-economic and other drivers of landscape change in study area are discussed.
Nash, J. Thomas
1999-01-01
Field observations, sampling of mine dumps and mine drainage waters, and laboratory studies of dump materials have been made at mining areas deemed to be on public lands administered by the U. S. Bureau of Land Management (BLM) in the Upper Animas River watershed. Results of chemical analyses of dump materials, leachates of those materials, and surface waters draining mines or dumps provide indications of where acid is generated or consumed, and metal concentrations below mines or dumps. Information on sites previously identified as needing reclamation is reviewed and available geochemical information is used to rank 26 sites into four classes of priority for reclamation. Although there are more than a thousand mining sites (productive mines and prospects) on BLM lands in the Upper Animas River watershed study area, the majority are very small (less than about 70 cubic yards of dump material), are more than 2 miles from a major stream, or so inaccessible as to prohibit reclamation. In the summers of 1997 and 1998 approximately 200 sites were observed and more than 100 of these that appeared to have the potential to geochemically impact the watershed were examined more carefully and sampled. Building upon the prior work of the BLM and associated agencies, this work attempted to identify the most significant sources of mine-related contamination and to rank those sites as to priority for reclamation. These most significant mining areas have been examined within a geologic framework and were evaluated by multiple criteria, including tendency to generate acid and release toxic metals, observed damage to vegetation, potential to release metals based on leach tests, and likelihood of transport into streams of the watershed. No single measurable parameter, such as metal concentration, can be used to rank the sites. Rather, subjective estimates are required to evaluate combinations or interactions among several parameters. The most subjective estimate, while ranking feasibility of reclamation, is the relative amounts of naturally occurring metals and acidity and mine-related contamination at each mining area. Mitigation of natural contributions at mines or unmined areas is beyond the scope of my studies, but should be considered when planning reclamation. Available information for the 26 priority sites is adequate for ranking, but at some sites additional information on groundwater conditions is needed for a more complete site evaluation.
Hydrogeology and Ground-Water Flow in the Opequon Creek Watershed area, Virginia and West Virginia
Kozar, Mark D.; Weary, David J.
2009-01-01
Due to increasing population and economic development in the northern Shenandoah Valley of Virginia and West Virginia, water availability has become a primary concern for water-resource managers in the region. To address these issues, the U.S. Geological Survey (USGS), in cooperation with the West Virginia Department of Health and Human Services and the West Virginia Department of Environmental Protection, developed a numerical steady-state simulation of ground-water flow for the 1,013-square-kilometer Opequon Creek watershed area. The model was based on data aggregated for several recently completed and ongoing USGS hydrogeologic investigations conducted in Jefferson, Berkeley, and Morgan Counties in West Virginia and Clarke, Frederick, and Warren Counties in Virginia. A previous detailed hydrogeologic assessment of the watershed area of Hopewell Run (tributary to the Opequon Creek), which includes the USGS Leetown Science Center in Jefferson County, West Virginia, provided key understanding of ground-water flow processes in the aquifer. The ground-water flow model developed for the Opequon Creek watershed area is a steady-state, three-layer representation of ground-water flow in the region. The primary objective of the simulation was to develop water budgets for average and drought hydrologic conditions. The simulation results can provide water managers with preliminary estimates on which water-resource decisions may be based. Results of the ground-water flow simulation of the Opequon Creek watershed area indicate that hydrogeologic concepts developed for the Hopewell Run watershed area can be extrapolated to the larger watershed model. Sensitivity analyses conducted as part of the current modeling effort and geographic information system analyses of spring location and yield reveal that thrust and cross-strike faults and low-permeability bedding, which provide structural and lithologic controls, respectively, on ground-water flow, must be incorporated into the model to develop a realistic simulation of ground-water flow in the larger Opequon Creek watershed area. In the model, recharge for average hydrologic conditions was 689 m3/d/km2 (cubic meters per day per square kilometer) over the entire Opequon Creek watershed area. Mean and median measured base flows at the streamflow-gaging station on the Opequon Creek near Martinsburg, West Virginia, were 604,384 and 349,907 m3/d (cubic meters per day), respectively. The simulated base flow of 432,834 m3/d fell between the mean and median measured stream base flows for the station. Simulated base-flow yields for subwatersheds during average conditions ranged from 0 to 2,643 m3/d/km2, and the median for the entire Opequon Creek watershed area was 557 m3/d/km2. A drought was simulated by reducing model recharge by 40 percent, a rate that approximates the recharge during the prolonged 16-month drought that affected the region from November 1998 to February 2000. Mean and median measured streamflows for the Opequon Creek watershed area at the Martinsburg, West Virginia, streamflow-gaging station during the 1999 drought were 341,098 and 216,551 m3/d, respectively. The simulated drought base flow at the station of 252,356 m3/d is within the range of flows measured during the 1999 drought. Recharge was 413 m3/d/km2 over the entire watershed during the simulated drought, and was 388 m3/d/km2 at the gaging station. Simulated base-flow yields for drought conditions ranged from 0 to 1,865 m3/d/km2 and averaged 327 m3/d/km2 over the entire Opequon Creek watershed. Water budgets developed from the simulation results indicate a substantial component of direct ground-water discharge to the Potomac River. This phenomenon had long been suspected but had not been quantified. During average conditions, approximately 564,176 m3/d of base flow discharges to the Potomac River. An additional 124,379 m3/d of ground water is also estimated to discharge directly to the Potomac River and rep
Christensen, V.G.; Pope, L.M.
1997-01-01
A network of 34 stream sampling sites was established in the 1,005-square-mile Cheney Reservoir watershed, south-central Kansas, to evaluate spatial variability in concentrations of selected water-quality constituents during low flow. Land use in the Cheney Reservoir watershed is almost entirely agricultural, consisting of pasture and cropland. Cheney Reservoir provides 40 to 60 percent of the water needs for the city of Wichita, Kansas. Sampling sites were selected to determine the relative contribution of point and nonpoint sources of water-quality constituents to streams in the watershed and to identify areas of potential water-quality concern. Water-quality constituents of interest included dissolved solids and major ions, nitrogen and phosphorus nutrients, atrazine, and fecal coliform bacteria. Water from the 34 sampling sites was sampled once in June and once in September 1996 during Phase I of a two-phase study to evaluate water-quality constituent concentrations and loading characteristics in selected subbasins within the watershed and into and out of Cheney Reservoir. Information summarized in this report pertains to Phase I and was used in the selection of six long-term monitoring sites for Phase II of the study. The average low-flow constituent concentrations in water collected during Phase I from all sampling sites was 671 milligrams per liter for dissolved solids, 0.09 milligram per liter for dissolved ammonia as nitrogen, 0.85 milligram per liter for dissolved nitrite plus nitrate as nitrogen, 0.19 milligram per liter for total phosphorus, 0.20 microgram per liter for dissolved atrazine, and 543 colonies per 100 milliliters of water for fecal coliform bacteria. Generally, these constituents were of nonpoint-source origin and, with the exception of dissolved solids, probably were related to agricultural activities. Dissolved solids probably occur naturally as the result of the dissolution of rocks and ancient marine sediments containing large salt deposits. Nutrients also may have resulted from point-source discharges from wastewater-treatment plants. An examination of water-quality characteristics during low flow in the Cheney Reservoir watershed provided insight into the spatial variability of water-quality constituents and allowed for between-site comparisons under stable-flow conditions; identified areas of the watershed that may be of particular water-quality concern; provided a preliminary evaluation of contributions from point and nonpoint sources of contamination; and identified areas of the watershed where long-term monitoring may be appropriate to quantify perceived water-quality problems.
Long-Ming Huang
2000-01-01
Improper cultivation of steep mountainous areas in Taiwan contributes to serious erosion and landslides. Regular patrol, detection, and administration of these problem areas has been an extremely difficult due to the steep and dangerous terrain of many of the forested watersheds in Taiwan. A remotely piloted vehicle (RPV) has been developed for various civil and...
Depressional wetlands affect watershed hydrological, biogeochemical, and ecological functions.
Evenson, Grey R; Golden, Heather E; Lane, Charles R; McLaughlin, Daniel L; D'Amico, Ellen
2018-06-01
Depressional wetlands of the extensive U.S. and Canadian Prairie Pothole Region afford numerous ecosystem processes that maintain healthy watershed functioning. However, these wetlands have been lost at a prodigious rate over past decades due to drainage for development, climate effects, and other causes. Options for management entities to protect the existing wetlands, and their functions, may focus on conserving wetlands based on spatial location vis-à-vis a floodplain or on size limitations (e.g., permitting smaller wetlands to be destroyed but not larger wetlands). Yet the effects of such management practices and the concomitant loss of depressional wetlands on watershed-scale hydrological, biogeochemical, and ecological functions are largely unknown. Using a hydrological model, we analyzed how different loss scenarios by wetland size and proximal location to the stream network affected watershed storage (i.e., inundation patterns and residence times), connectivity (i.e., streamflow contributing areas), and export (i.e., streamflow) in a large watershed in the Prairie Pothole Region of North Dakota, USA. Depressional wetlands store consequential amounts of precipitation and snowmelt. The loss of smaller depressional wetlands (<3.0 ha) substantially decreased landscape-scale inundation heterogeneity, total inundated area, and hydrological residence times. Larger wetlands act as hydrologic "gatekeepers," preventing surface runoff from reaching the stream network, and their modeled loss had a greater effect on streamflow due to changes in watershed connectivity and storage characteristics of larger wetlands. The wetland management scenario based on stream proximity (i.e., protecting wetlands 30 m and ~450 m from the stream) alone resulted in considerable landscape heterogeneity loss and decreased inundated area and residence times. With more snowmelt and precipitation available for runoff with wetland losses, contributing area increased across all loss scenarios. We additionally found that depressional wetlands attenuated peak flows; the probability of increased downstream flooding from wetland loss was also consistent across all loss scenarios. It is evident from this study that optimizing wetland management for one end goal (e.g., protection of large depressional wetlands for flood attenuation) over another (e.g., protecting of small depressional wetlands for biodiversity) may come at a cost for overall watershed hydrological, biogeochemical, and ecological resilience, functioning, and integrity. © 2018 by the Ecological Society of America.
NASA Astrophysics Data System (ADS)
Sanchez-Murillo, R.; Brooks, E. S.; Boll, J.; Elliot, W.
2012-12-01
Baseflow is one of the most important components of the streamflow regime of any river or creek since it provides continuous habitat to aquatic biota; regulates water temperature and dissolved oxygen during summer; and functions as an essential supply for drinking water and irrigation in most temperate regions. Understanding which factors control how water is released to streams during baseflow periods has become critical for watershed management worldwide, especially, in arid and semiarid areas. This study analyzed storage-discharge relationships of 26 watersheds of northern Idaho and eastern Washington using Brutsaert and Nieber (1977) baseflow recession analysis. Daily streamflow and precipitation records ranged from 7 to 70 years. Mean annual precipitation fluctuated from 536 to 1,312 mm. Drainage basin areas varied from 6.35 to 12,357 km2, with streamgage elevation ranging from 536 to 2,172 m. Mean watershed slope varied from 9.24 to 46.53%. Because of the non-uniqueness watershed shapes, illustrated by the natural spectrum of data points, organic correlation analysis was used to determine the recession coefficients (kb). Numerous climatic attributes and geomorphology characteristics were evaluated as potential predictors of kb rates using a Pearson's correlation matrix. Baseflow coefficients ranged from 0.015 to 0.08 day-1. The mean characteristic timescale for baseflow drainage was found to be 33±15 days with extremes of 12.5 and 66.7 days. Watersheds dominated by basalt features showed the lowest drainage times (12.5-20.0 days). The drainage time increased as the metamorphic and sedimentary rock composition increased (33.3-66.7 days). Watersheds mainly composed by granitic features ranged from 29.1 to 50.0 days. The ratio of mean annual precipitation (MAP) to annual potential evapotranspiration (PET), also known as Aridity Index (AI), was found to explain 67% of kb variability. Mean watershed slope exhibited a moderate negative correlation of -0.57. Other topography attributes such as drainage density, stream length, and total relief were weakly correlated. This detailed baseflow characterization may lead to better management practices in ungauged areas that share similar underlying geology and climates. By knowing baseflow characteristics, stakeholders and environmental agencies could prioritize efforts and resources in areas where potential future droughts may drastically affect ecological assemblages and socio-economical activities.
NASA Astrophysics Data System (ADS)
Bugaets, Andrey; Gartsman, Boris; Bugaets, Nadezhda
2013-04-01
Generally, the investigation of river network composition and watersheds morphology (fluvial geomorphology), constituting one of the key patterns of land surface, is a fundamental question of Earth Sciences. Recent ideas in this research field are the equilibrium and optimal, in the sense of minimum energy expenditure, river network evolution under constant or slowly varying conditions (Rodriguez-Iturbe, Rinaldo, 1997). It follows to such network behavior as self-similarity, self-affinity and self-organization. That is to say, under relatively stable conditions the river systems tend to some "good composed" form and vice-versa. Lately appearing global free available detailed DEM covers involve new possibilities in this research field. We develop new methodology and program package for river network structure and watershed morphology detailed analysis on the base of ArcMap tools. Different characteristics of river network (e.g. ordering, coefficients of Horton's laws, Shannon entropy, fractal dimension) and basin morphology (e.g. diagrams of average elevation, slope, width and energy index against distance to outlet along streams) could be calculated to find a good indicators of intensity and non-equilibrium of watershed evolution. Watersheds are non-conservative systems in which energy is dissipated by transporting water and sediment in geomorphic adjustment of the slopes and channels. The problem of estimating the amount of energy expenditure associated with overcoming surface and system resistance is extremely complicated to solve. A simplification on a river network scale is to consider energy expenditure to be primarily associated with friction of the fluid. We propose a new technique to analyze the catchment landforms based on so-called "energy function" that is a distribution of total energy index against distance from outlet. As potential energy of water on the hillslopes is transformed into kinetic energy of the flowing fluid-sediment mixture in the runoff process, the energy is dissipated from the system. The rate of energy dissipation is defined as the work that a fluid element needs to perform to overcome friction at the unit area. Appling the product of local slope and watershed area, i.e. calculating the total energy index at the different distance from outlet, one gets the watershed "energy function" E(x). Application results indicate that the proposed method could be used for watersheds classification, regionalization and paleoreconstructions. NASA-SRTM DEM of 3" resolution has been employed to analyze the 24 watersheds within Amur River Basin with area 20-70 thousand km2 (7-8 order). The study was carried out, in particular, to assess the limitation of SRTM DEM data, especially in flat terrains. The study also revealed that some of regularities investigated are described satisfactorily by well-known simplest model of drainage networks, so-called Peano's basin.
Landslide potential zonation in Baleghlu watershed (NW Iran) using AHP Fuzzy method
NASA Astrophysics Data System (ADS)
Jananeh, Keristineh; Roostai, Shahram
2017-04-01
Landslides and slope instabilities are among the important natural hazards, which cause human and financial casualties and loss of economic resources every year. These hazards mostly occur in natural slopes or those manipulated by human. Zonation of areas with regard to landslide potential is one of the means to identify areas prone to produce landslide and so, to conduct plannings and management based on the prepared zonation maps in order to reduce the casualties. This contribution investigates on the landslide potential zonation within the Baleghlu watershed. This watershed is located in the southeast of Sabalan volcano (NW Iran) within the longitudes of 47° 48` and 48° 12` E and northern latitudes of 37° 51` and 38° 16` N. Its main river is Baleghlu, which is later connected to the Arax river through the Qarasu and Dareh Roud rivers, and is finally terminated to the Caspian sea. The method of investigation is Fuzzy AHP in the GIS environment. First, the main factors including the slope and its direction, geology, soil, climate, distance from the road and river and land usage were investigated and then, after preparing data layers based on the above-mentioned parameters and giving weights to them in the GIS environment, the landslide potential map was prepared by Fuzzy AHP method. It was revealed that the slope factor with the value of 0.3882 has the highest weight, while the land usage factor with the value of 0.0287 has the lowest weight. According to the final zonation map of the landslide potential, the watershed was divided into 5 classes, ranging from very high potential class to the very low potential. The obtained results showed that the largest part of the watershed (32.21%) has low landslide potential, while about 13.5% of it has very high potential. Areas with very high and high landslide potential (327.39 km2 area) are mainly located in the northwest of the watershed, with some small areas distributed in the south and east, while areas with very low and low potential (504.06 km2) are mainly found in the central to northwestern and southern parts of the watershed.
Multivariate Statistical Models for Predicting Sediment Yields from Southern California Watersheds
Gartner, Joseph E.; Cannon, Susan H.; Helsel, Dennis R.; Bandurraga, Mark
2009-01-01
Debris-retention basins in Southern California are frequently used to protect communities and infrastructure from the hazards of flooding and debris flow. Empirical models that predict sediment yields are used to determine the size of the basins. Such models have been developed using analyses of records of the amount of material removed from debris retention basins, associated rainfall amounts, measures of watershed characteristics, and wildfire extent and history. In this study we used multiple linear regression methods to develop two updated empirical models to predict sediment yields for watersheds located in Southern California. The models are based on both new and existing measures of volume of sediment removed from debris retention basins, measures of watershed morphology, and characterization of burn severity distributions for watersheds located in Ventura, Los Angeles, and San Bernardino Counties. The first model presented reflects conditions in watersheds located throughout the Transverse Ranges of Southern California and is based on volumes of sediment measured following single storm events with known rainfall conditions. The second model presented is specific to conditions in Ventura County watersheds and was developed using volumes of sediment measured following multiple storm events. To relate sediment volumes to triggering storm rainfall, a rainfall threshold was developed to identify storms likely to have caused sediment deposition. A measured volume of sediment deposited by numerous storms was parsed among the threshold-exceeding storms based on relative storm rainfall totals. The predictive strength of the two models developed here, and of previously-published models, was evaluated using a test dataset consisting of 65 volumes of sediment yields measured in Southern California. The evaluation indicated that the model developed using information from single storm events in the Transverse Ranges best predicted sediment yields for watersheds in San Bernardino, Los Angeles, and Ventura Counties. This model predicts sediment yield as a function of the peak 1-hour rainfall, the watershed area burned by the most recent fire (at all severities), the time since the most recent fire, watershed area, average gradient, and relief ratio. The model that reflects conditions specific to Ventura County watersheds consistently under-predicted sediment yields and is not recommended for application. Some previously-published models performed reasonably well, while others either under-predicted sediment yields or had a larger range of errors in the predicted sediment yields.
NASA Astrophysics Data System (ADS)
Tesser, D.; Hoang, L.; McDonald, K. C.
2017-12-01
Efforts to improve municipal water supply systems increasingly rely on an ability to elucidate variables that drive hydrologic dynamics within large watersheds. However, fundamental model variables such as precipitation, soil moisture, evapotranspiration, and soil freeze/thaw state remain difficult to measure empirically across large, heterogeneous watersheds. Satellite remote sensing presents a method to validate these spatially and temporally dynamic variables as well as better inform the watershed models that monitor the water supply for many of the planet's most populous urban centers. PALSAR 2 L-band, Sentinel 1 C-band, and SMAP L-band scenes covering the Cannonsville branch of the New York City (NYC) water supply watershed were obtained for the period of March 2015 - October 2017. The SAR data provides information on soil moisture, free/thaw state, seasonal surface inundation, and variable source areas within the study site. Integrating the remote sensing products with watershed model outputs and ground survey data improves the representation of related processes in the Soil and Water Assessment Tool (SWAT) utilized to monitor the NYC water supply. PALSAR 2 supports accurate mapping of the extent of variable source areas while Sentinel 1 presents a method to model the timing and magnitude of snowmelt runoff events. SMAP Active Radar soil moisture product directly validates SWAT outputs at the subbasin level. This blended approach verifies the distribution of soil wetness classes within the watershed that delineate Hydrologic Response Units (HRUs) in the modified SWAT-Hillslope. The research expands the ability to model the NYC water supply source beyond a subset of the watershed while also providing high resolution information across a larger spatial scale. The global availability of these remote sensing products provides a method to capture fundamental hydrology variables in regions where current modeling efforts and in situ data remain limited.
NASA Astrophysics Data System (ADS)
Beighley, R. Edward; Moglen, Glenn E.
2003-04-01
A procedure to adjust gauged streamflow data from watersheds urbanized during or after their gauging period is presented. The procedure adjusts streamflow to be representative of a fixed land use condition, which may reflect current or future development conditions. Our intent is to determine what an event resulting in a peak discharge in, for example, 1950 (i.e., before urbanization) would produce on the current urban watershed. While past approaches assumed uniform spatial and temporal changes in urbanization, this study focuses on the use of geographic information systems (GIS) based methodologies for precisely locating in space and time where land use change has occurred. This information is incorporated into a hydrologic model to simulate the change in discharge as a result of changing land use conditions. In this paper, we use historical aerial photographs, GIS linked tax-map data, and recent land use/land cover data to recreate the spatial development history of eight gauged watersheds in the Baltimore-Washington, D. C., metropolitan area. Using our procedure to determine discharge series representative of the current urban watersheds, we found that the increase of the adjusted 2-year discharge ranged from 16 to 70 percent compared with the measured annual maximum discharge series. For the 100-year discharge the adjusted values ranged from 0 to 47 percent greater than the measured values. Additionally, relationships between the increase in flood flows and four measures of urbanization (increase in urban land, decrease in forested land, increase in high-density development, and the spatial development pattern) are investigated for predicting the increase in flood flows for ungauged watersheds. Watersheds with the largest increases in flood flows typically had more extensive development in the areas far removed from the outlet. In contrast, watersheds with development located nearer to the outlet typically had the smallest increases in peak discharge.
Downstream cumulative effects of land use on freshwater communities
NASA Astrophysics Data System (ADS)
Kuglerová, L.; Kielstra, B. W.; Moore, D.; Richardson, J. S.
2015-12-01
Many streams and rivers are subject to disturbance from intense land use such as urbanization and agriculture, and this is especially obvious for small headwaters. Streams are spatially organized into networks where headwaters represent the tributaries and provide water, nutrients, and organic material to the main stems. Therefore perturbations within the headwaters might be cumulatively carried on downstream. Although we know that the disturbance of headwaters in urban and agricultural landscapes poses threats to downstream river reaches, the magnitude and severity of these changes for ecological communities is less known. We studied stream networks along a gradient of disturbance connected to land use intensity, from urbanized watersheds to watersheds placed in agricultural settings in the Greater Toronto Area. Further, we compared the patterns and processes found in the modified watershed to a control watershed, situated in a forested, less impacted landscape. Preliminary results suggest that hydrological modifications (flash floods), habitat loss (drainage and sewer systems), and water quality issues of small streams in urbanized and agricultural watersheds represent major disturbances and threats for aquatic and riparian biota on local as well as larger spatial scales. For example, communities of riparian plants are dominated by species typical of the land use on adjacent uplands as well as the dominant land use on the upstream contributing area, instead of riparian obligates commonly found in forested watersheds. Further, riparian communities in disturbed environments are dominated by invasive species. The changes in riparian communities are vital for various functions of riparian vegetation. Bank erosion control is suppressed, leading to severe channel transformations and sediment loadings in urbanized watersheds. Food sources for instream biota and thermal regimes are also changed, which further triggers alterations of in-stream biological communities. These findings clearly demonstrate that in watersheds which are disturbed by intensive land use, the eco-hydrological linkages between biota and fluvial processes significantly differ from those in more natural and forested landscapes.
Arp, C.D.; Whitman, M.S.; Jones, Benjamin M.; Kemnitz, R.; Grosse, G.; Urban, F.E.
2012-01-01
Watersheds draining the Arctic Coastal Plain (ACP) of Alaska are dominated by permafrost and snowmelt runoff that create abundant surface storage in the form of lakes, wetlands, and beaded streams. These surface water elements compose complex drainage networks that affect aquatic ecosystem connectivity and hydrologic behavior. The 4676 km2 Fish Creek drainage basin is composed of three watersheds that represent a gradient of the ACP landscape with varying extents of eolian, lacustrine, and fluvial landforms. In each watershed, we analyzed 2.5-m-resolution aerial photography, a 5-m digital elevation model, and river gauging and climate records to better understand ACP watershed structure and processes. We show that connected lakes accounted for 19 to 26% of drainage density among watersheds and most all channels initiate from lake basins in the form of beaded streams. Of the > 2500 lakes in these watersheds, 33% have perennial streamflow connectivity, and these represent 66% of total lake area extent. Deeper lakes with over-wintering habitat were more abundant in the watershed with eolian sand deposits, while the watershed with marine silt deposits contained a greater extent of beaded streams and shallow thermokarst lakes that provide essential summer feeding habitat. Comparison of flow regimes among watersheds showed that higher lake extent and lower drained lake-basin extent corresponded with lower snowmelt and higher baseflow runoff. Variation in baseflow runoff among watersheds was most pronounced during drought conditions in 2007 with corresponding reduction in snowmelt peak flows the following year. Comparison with other Arctic watersheds indicates that lake area extent corresponds to slower recession of both snowmelt and baseflow runoff. These analyses help refine our understanding of how Arctic watersheds are structured and function hydrologically, emphasizing the important role of lake basins and suggesting how future lake change may impact hydrologic processes.
NASA Astrophysics Data System (ADS)
Teale, N. G.; Quiring, S. M.
2015-12-01
Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.
NASA Astrophysics Data System (ADS)
Latorre Torres, I. B.; Amatya, D. M.; Callahan, T. J.; Levine, N. S.
2007-12-01
Hydrology research in the Southeast U.S. has primarily focused on upland mountainous areas; however, much less is known about hydrological processes in Lower Coastal Plain (LCP) watersheds. Such watersheds are difficult to characterize due to shallow water table conditions, low topographic gradient, complex surface- subsurface water interaction, and lack of detailed soil information. Although opportunities to conduct long term monitoring in relatively undeveloped watersheds are often limited, stream flow and rainfall in the Turkey Creek watershed (third-order watershed, about 7200 ha in the Francis Marion National Forest near Charleston, SC) have been monitored since 1964. In this study, event runoff-rainfall ratios have been determined for 51 storm events using historical data from 1964-1973. One of our objectives was to characterize relationships between seasonal event rainfall and storm outflow in this watershed. To this end, observed storm event data were compared with values predicted by established hydrological methods such as the Soil Conservation Service runoff curve number (SCS-CN) and the rational method integrated within a Geographical Information System (GIS), to estimate total event runoff and peak discharge, respectively. Available 1:15000 scale aerial images were digitized to obtain land uses, which were used with the SCS soil hydrologic groups to obtain the runoff coefficients (C) for the rational method and the CN values for the SCS-CN method. These methods are being tested with historical storm event responses in the Turkey Creek watershed scale, and then will be used to predict event runoff in Quinby Creek, an ungauged third-order watershed (8700 ha) adjacent to Turkey Creek. Successful testing with refinement of parameters in the rational method and SCS-CN method, both designed for small urban and agricultural dominated watersheds, may allow widespread application of these methods for studying the event rainfall-runoff dynamics for similar watersheds in the Lower Coastal Plain of the Southeast U.S.
Arenas Amado, A; Schilling, K E; Jones, C S; Thomas, N; Weber, L J
2017-09-01
Nitrogen losses from artificially drained watersheds degrade water quality at local and regional scales. In this study, we used an end-member mixing analysis (EMMA) together with high temporal resolution water quality and streamflow data collected in the 122 km 2 Otter Creek watershed located in northeast Iowa. We estimated the contribution of three end-members (groundwater, tile drainage, and quick flow) to streamflow and nitrogen loads and tested several combinations of possible nitrate concentrations for the end-members. Results indicated that subsurface tile drainage is responsible for at least 50% of the watershed nitrogen load between April 15 and November 1, 2015. Tiles delivered up to 80% of the stream N load while providing only 15-43% of the streamflow, whereas quick flows only marginally contributed to N loading. Data collected offer guidance about areas of the watershed that should be targeted for nitrogen export mitigation strategies.
Soil wettability and wetting agents . . . our current knowledge of the problem
Leonard F. DeBano; Joseph F. Osborn; Jay S. Krammes; John Letey
1967-01-01
Soils that resist wetting are a widespread phenomenon on chaparral areas of southern California watersheds. On burned watersheds, non-wettable soils markedly reduce moisture movement during both evaporation and infiltration. The reduced infiltration rate probably contributes significantly to the high debris production from the watersheds. Factors involved in the...
Climate and hydrology of the Entiat Experimental Forest watersheds under virgin forest cover.
J.D. Helvey; W.B. Fowler; G.O. Klock; A.R. Tiedemann
1976-01-01
Climatic and hydrologic measurements were made on three watersheds, each containing approximately 2 square miles (5.18 km2) of drainage area, for 9 years under natural forested conditions. This paper describes the watersheds with respect to soils and geology, morphology, vegetation, precipitation and other climatic parameters, and flow, sediment...
Watershed management implications of agroforestry expansion on Minnesota's farmlands
C. Hobart Perry; Ryan C. Miller; Anthony R. Kaster; Kenneth N. Brooks
2000-01-01
Minnesotaâs agricultural landscape is changing. The increasing use of woody perennials in agricultural fields, living snow fences, windbreaks, and riparian areas has important watershed management implications for agricultural watersheds in northwestern Minnesota. These changes in land use could lead to reductions in annual water yield, annual flood peaks, and dry...
Located in southwestern Minnesota, the Redwood River watershed lies within an area of the Prairie Pothole Region where land use is predominantly a mixture of row crop and livestock agriculture. In 2003 the condition of emergent depressional wetlands in this watershed was assesse...
2013-01-01
Background Tribal people in India, as in other parts of the world, reside mostly in forests and/or hilly terrains. Water scarcity and health problems related to it are their prime concern. Watershed management can contribute to resolve their health related problems and can put them on a path of socio-economic development. Integrated management of land, water and biomass resources within a watershed, i.e. in an area or a region which contributes rainfall water to a river or lake, is referred to as watershed management. Watershed management includes soil and water conservation to create water resources, management of drinking water, improving hygiene and sanitation, plantation of trees, improving agriculture, formation of self-help groups and proper utilisation and management of available natural resources. For successful implementation of such a solution, understanding of perceptions of the tribal community members with regard to public health and socioeconomic implications of watershed management is essential. Methods A qualitative study with six focus group discussions (FGDs), three each separately for men and women, was conducted among tribal community members of the Maharashtra state of India. The data collected from the FGDs were analyzed using manifest and latent content analysis. Results “Improvement in health and empowerment of families as a result of watershed management” was identified as the main theme. Participants perceived that their health problems and socio-economic development are directly and/or indirectly dependent upon water availability. They further perceived that watershed management could directly or indirectly result in reduction of their public health related challenges like waterborne diseases, seasonal migration, alcoholism, intimate partner violence, as well as drudgery of women and may enhance overall empowerment of families through agricultural development. Conclusions Tribal people perceived that water scarcity is the main reason for their physical, mental and social health problems and a major obstacle for their overall development. The perceptions of tribal participants indicate that infectious diseases, migration, alcoholism, intimate partner violence and drudgery of women are end results of water scarcity and efforts to increase water availability through watershed management may help them to achieve their right to health which is embedded in their right to access to water. PMID:24119537
Nerkar, Sandeep S; Tamhankar, Ashok J; Johansson, Eva; Lundborg, Cecilia Stålsby
2013-10-12
Tribal people in India, as in other parts of the world, reside mostly in forests and/or hilly terrains. Water scarcity and health problems related to it are their prime concern. Watershed management can contribute to resolve their health related problems and can put them on a path of socio-economic development. Integrated management of land, water and biomass resources within a watershed, i.e. in an area or a region which contributes rainfall water to a river or lake, is referred to as watershed management. Watershed management includes soil and water conservation to create water resources, management of drinking water, improving hygiene and sanitation, plantation of trees, improving agriculture, formation of self-help groups and proper utilisation and management of available natural resources. For successful implementation of such a solution, understanding of perceptions of the tribal community members with regard to public health and socioeconomic implications of watershed management is essential. A qualitative study with six focus group discussions (FGDs), three each separately for men and women, was conducted among tribal community members of the Maharashtra state of India. The data collected from the FGDs were analyzed using manifest and latent content analysis. "Improvement in health and empowerment of families as a result of watershed management" was identified as the main theme. Participants perceived that their health problems and socio-economic development are directly and/or indirectly dependent upon water availability. They further perceived that watershed management could directly or indirectly result in reduction of their public health related challenges like waterborne diseases, seasonal migration, alcoholism, intimate partner violence, as well as drudgery of women and may enhance overall empowerment of families through agricultural development. Tribal people perceived that water scarcity is the main reason for their physical, mental and social health problems and a major obstacle for their overall development. The perceptions of tribal participants indicate that infectious diseases, migration, alcoholism, intimate partner violence and drudgery of women are end results of water scarcity and efforts to increase water availability through watershed management may help them to achieve their right to health which is embedded in their right to access to water.
DEM time series of an agricultural watershed
NASA Astrophysics Data System (ADS)
Pineux, Nathalie; Lisein, Jonathan; Swerts, Gilles; Degré, Aurore
2014-05-01
In agricultural landscape soil surface evolves notably due to erosion and deposition phenomenon. Even if most of the field data come from plot scale studies, the watershed scale seems to be more appropriate to understand them. Currently, small unmanned aircraft systems and images treatments are improving. In this way, 3D models are built from multiple covering shots. When techniques for large areas would be to expensive for a watershed level study or techniques for small areas would be too time consumer, the unmanned aerial system seems to be a promising solution to quantify the erosion and deposition patterns. The increasing technical improvements in this growth field allow us to obtain a really good quality of data and a very high spatial resolution with a high Z accuracy. In the center of Belgium, we equipped an agricultural watershed of 124 ha. For three years (2011-2013), we have been monitoring weather (including rainfall erosivity using a spectropluviograph), discharge at three different locations, sediment in runoff water, and watershed microtopography through unmanned airborne imagery (Gatewing X100). We also collected all available historical data to try to capture the "long-term" changes in watershed morphology during the last decades: old topography maps, soil historical descriptions, etc. An erosion model (LANDSOIL) is also used to assess the evolution of the relief. Short-term evolution of the surface are now observed through flights done at 200m height. The pictures are taken with a side overlap equal to 80%. To precisely georeference the DEM produced, ground control points are placed on the study site and surveyed using a Leica GPS1200 (accuracy of 1cm for x and y coordinates and 1.5cm for the z coordinate). Flights are done each year in December to have an as bare as possible ground surface. Specific treatments are developed to counteract vegetation effect because it is know as key sources of error in the DEM produced by small unmanned aircraft systems. The poster will present the older and more recent changes of relief in this intensely exploited watershed and notably show how unmanned airborne imagery might be of help in DEM dynamic modelling to support soil conservation research.
NASA Astrophysics Data System (ADS)
Behera, Mukunda D.; Borate, Santosh N.; Panda, Sudhindra N.; Behera, Priti R.; Roy, Partha S.
2012-08-01
Improper practices of land use and land cover (LULC) including deforestation, expansion of agriculture and infrastructure development are deteriorating watershed conditions. Here, we have utilized remote sensing and GIS tools to study LULC dynamics using Cellular Automata (CA)-Markov model and predicted the future LULC scenario, in terms of magnitude and direction, based on past trend in a hydrological unit, Choudwar watershed, India. By analyzing the LULC pattern during 1972, 1990, 1999 and 2005 using satellite-derived maps, we observed that the biophysical and socio-economic drivers including residential/industrial development, road-rail and settlement proximity have influenced the spatial pattern of the watershed LULC, leading to an accretive linear growth of agricultural and settlement areas. The annual rate of increase from 1972 to 2004 in agriculture land, settlement was observed to be 181.96, 9.89 ha/year, respectively, while decrease in forest, wetland and marshy land were 91.22, 27.56 and 39.52 ha/year, respectively. Transition probability and transition area matrix derived using inputs of (i) residential/industrial development and (ii) proximity to transportation network as the major causes. The predicted LULC scenario for the year 2014, with reasonably good accuracy would provide useful inputs to the LULC planners for effective management of the watershed. The study is a maiden attempt that revealed agricultural expansion is the main driving force for loss of forest, wetland and marshy land in the Choudwar watershed and has the potential to continue in future. The forest in lower slopes has been converted to agricultural land and may soon take a call on forests occurring on higher slopes. Our study utilizes three time period changes to better account for the trend and the modelling exercise; thereby advocates for better agricultural practices with additional energy subsidy to arrest further forest loss and LULC alternations.
Nerkar, Sandeep S.; Tamhankar, Ashok J.; Johansson, Eva; Lundborg, Cecilia Stålsby
2016-01-01
Lack of access to water has a significant impact on the health of people in tribal areas, where water in households as well as for productive purposes is essential for life. In resource-limited settings such as hilly tribal areas, implementation of an integrated watershed management programme (IWMP) can have a significant impact on public health by providing a solution to water scarcity and related problems. The professional stakeholders in rural healthcare and development administration are important pillars of the system that implements various programmes and policies of government and non-government organizations, and act as facilitators for the improvement of public health in tribal areas. Information about the perceptions of these stakeholders on public health implications of the integrated watershed management programme is important in this context. A qualitative study was conducted using face to face semi-structured interviews and focus group discussions (FGDs) with stakeholders involved in healthcare provision, education and development administration. The transcripts of interviews and FGDs were analyzed using manifest and latent content analysis. The perceptions and experiences shared by healthcare and development administration stakeholders suggest that implementation of IWMP in tribal areas helps efficient water and agriculture management, which results in improved socio-economic conditions that lead to positive health outcomes. PMID:26959039
Nerkar, Sandeep S; Tamhankar, Ashok J; Johansson, Eva; Lundborg, Cecilia Stålsby
2016-03-04
Lack of access to water has a significant impact on the health of people in tribal areas, where water in households as well as for productive purposes is essential for life. In resource-limited settings such as hilly tribal areas, implementation of an integrated watershed management programme (IWMP) can have a significant impact on public health by providing a solution to water scarcity and related problems. The professional stakeholders in rural healthcare and development administration are important pillars of the system that implements various programmes and policies of government and non-government organizations, and act as facilitators for the improvement of public health in tribal areas. Information about the perceptions of these stakeholders on public health implications of the integrated watershed management programme is important in this context. A qualitative study was conducted using face to face semi-structured interviews and focus group discussions (FGDs) with stakeholders involved in healthcare provision, education and development administration. The transcripts of interviews and FGDs were analyzed using manifest and latent content analysis. The perceptions and experiences shared by healthcare and development administration stakeholders suggest that implementation of IWMP in tribal areas helps efficient water and agriculture management, which results in improved socio-economic conditions that lead to positive health outcomes.
Trends in the sediment yield of the Sacramento River, California, 1957-2001
Wright, Scott A.; Schoellhamer, David H.
2004-01-01
Human activities within a watershed, such as agriculture, urbanization, and dam building, may affect the sediment yield from the watershed. Because the equilibrium geomorphic form of an estuary is dependent in part on the sediment supply from the watershed, anthropogenic activities within the watershed have the potential to affect estuary geomorphology. The Sacramento River drains the northern half of California’s Central Valley and is the primary source of sediment to San Francisco Bay. In this paper, it is shown that the delivery of suspended-sediment from the Sacramento River to San Francisco Bay has decreased by about one-half during the period 1957 to 2001. Many factors may be contributing to the trend in sediment yield, including the depletion of erodible sediment from hydraulic mining in the late 1800s, trapping of sediment in reservoirs, riverbank protection, altered land-uses (such as agriculture, grazing, urbanization, and logging), and levees. This finding has implications for planned tidal wetland restoration activities around San Francisco Bay, where an adequate sediment supply will be needed to build subsided areas to elevations typical of tidal wetlands as well as to keep pace with projected sea-level rise. In a broader context, the study underscores the need to address anthropogenic impacts on watershed sediment yield when considering actions such as restoration within downstream depositional areas.
Xiao, Huaguo; Ji, Wei
2007-01-01
Landscape characteristics of a watershed are important variables that influence surface water quality. Understanding the relationship between these variables and surface water quality is critical in predicting pollution potential and developing watershed management practices to eliminate or reduce pollution risk. To understand the impacts of landscape characteristics on water quality in mine waste-located watersheds, we conducted a case study in the Tri-State Mining District which is located in the conjunction of three states (Missouri, Kansas and Oklahoma). Severe heavy metal pollution exists in that area resulting from historical mining activities. We characterized land use/land cover over the last three decades by classifying historical multi-temporal Landsat imagery. Landscape metrics such as proportion, edge density and contagion were calculated based on the classified imagery. In-stream water quality data over three decades were collected, including lead, zinc, iron, cadmium, aluminum and conductivity which were used as key water quality indicators. Statistical analyses were performed to quantify the relationship between landscape metrics and surface water quality. Results showed that landscape characteristics in mine waste-located watersheds could account for as much as 77% of the variation of water quality indicators. A single landscape metric alone, such as proportion of mine waste area, could be used to predict surface water quality; but its predicting power is limited, usually accounting for less than 60% of the variance of water quality indicators.
Hydrology of the Goat Lake watershed, Snohomish County, Washington, 1982-87
Dion, N.P.; Ebbert, J.C.; Poole, J.E.; Peck, B.S.
1989-01-01
The Goat Lake watershed in Snohomish County, Washington, functions as an ' experimental watershed ' for long-term studies to determine the effects of acidic precipitation on water resources. Data have been collected there by the U.S. Geological Survey since 1982. The watershed is in a wilderness area of the Cascade Range and is downwind of an industrial and urban area that produces chemical compounds found in acidic precipitation. The lake is considered sensitive to acidic inputs from atmospheric deposition and streamflow. The mean annual discharge of the Goat Lake outflow is 35 cu ft/sec; precipitation on the watershed is calculated to be about 170 in/yr. The inflow to Goat Lake is sufficient to replace the entire contents of the lake basin on an average every 21.5 days, or 17 times/year. Water in Goat Lake, and that of the inlet and outlet, is of low ionic strength and of calcium-bicarbonate type. The lake, although considered oligotrophic, is sufficiently deep to stratify thermally, and summer dissolved-oxygen concentrations in the hypolimnion are depressed. Even though alkalinity and specific conductance at Goat Lake are in the range considered sensitive to acidic inputs , the pH of water in the lake has consistently ranged from 6.1 to 7.2, indicating that the lake is not acidified at this time. (USGS)
NASA Astrophysics Data System (ADS)
Yang, G.; Best, E. P.; Goodwin, S.
2013-12-01
Non-point source (NPS) pollution is one of the leading causes of water quality impairment within the United States. Conservation, restoration and altered management (CRAM) practices may effectively reduce NPS pollutants to receiving water bodies and enhance local and regional ecosystem services. Barriers for the implementation of CRAM include uncertainties related to the extent to which nutrients are removed by CRAM at various spatial and temporal scales, longevity, optimal placement of CRAM within the landscape, and implementation / operation / maintenance costs. We conducted a study aimed at the identification of optimal placement of CRAM in watersheds that reduces N loading to an environmentally sustainable level, at an acceptable, known, cost. For this study, we used a recently developed screening-level modeling approach, WQM-TMDL-N, running in the ArcGIS environment, to estimate nitrogen loading under current land use conditions (NLCD 2006). This model was equipped with a new option to explore the performances of placement of various CRAM types and areas to reduce nitrogen loading to a State-accepted Total Maximum Daily Load (TMDL) standard, with related annual average TN concentration, and a multi-objective algorithm optimizing load and cost. CRAM practices explored for implementation in rural area included buffer strips, nutrient management practices, and wetland restoration. We initially applied this modeling approach to the Tippecanoe River (TR) watershed (8-digit HUC), a headwater of the Wabash River (WR) watershed, where CRAM implementation in rural and urban areas is being planned and implemented at various spatial scales. Consequences of future land use are explored using a 2050 land use/land cover map forecasted by the Land Transformation Model. The WR watershed, IN, drains two-thirds of the state's 92 counties and supports predominantly agricultural land use. Because the WR accounts for over 40% of the nutrient loads of the Ohio River and significantly contributes to the anoxic zone in the Gulf of Mexico (GOM), reduction in TN loading of the WR are expected to directly benefit downstream ecosystem services, including fisheries in the GOM. This modeling approach can be used in support of sustainable integrated watershed management planning.
Jennings, M.E.; Thomas, W.O.; Riggs, H.C.
1994-01-01
For many years, the U.S. Geological Survey (USGS) has been involved in the development of regional regression equations for estimating flood magnitude and frequency at ungaged sites. These regression equations are used to transfer flood characteristics from gaged to ungaged sites through the use of watershed and climatic characteristics as explanatory or predictor variables. Generally these equations have been developed on a statewide or metropolitan area basis as part of cooperative study programs with specific State Departments of Transportation or specific cities. The USGS, in cooperation with the Federal Highway Administration and the Federal Emergency Management Agency, has compiled all the current (as of September 1993) statewide and metropolitan area regression equations into a micro-computer program titled the National Flood Frequency Program.This program includes regression equations for estimating flood-peak discharges and techniques for estimating a typical flood hydrograph for a given recurrence interval peak discharge for unregulated rural and urban watersheds. These techniques should be useful to engineers and hydrologists for planning and design applications. This report summarizes the statewide regression equations for rural watersheds in each State, summarizes the applicable metropolitan area or statewide regression equations for urban watersheds, describes the National Flood Frequency Program for making these computations, and provides much of the reference information on the extrapolation variables needed to run the program.
CHARACTERIZATION OF LAND USE IN RIPARIAN AREAS WITHIN THE CONTENTNEA WATERSHED OF NORTH CAROLINA
Characterization of land use in riparian areas within the Contentnea watershed of North Carolina.
Wright, C.J.,1 and S.W. Alberty.2 1U.S. Environmental Protection Agency, Athens, GA 30605 USA; 2OAO Corporation, Athens, GA 30605 USA.
Legislation mandating riparian bu...
NASA Astrophysics Data System (ADS)
Berg, M.; Wilcox, B. P.; Angerer, J.; Marcantonio, F.; Fox, W.; Popescu, S. C.
2013-12-01
Long-running abandonment of marginal croplands and woody plant encroachment have been observed in many landscapes around world, often in association with one another. However, there is great uncertainty about the consequences of these trends, and very few studies have examined impacts at the watershed scale. In watersheds totaling 230km2 in Texas, we used an integrated approach of sediment chronosequencing, historical imagery analysis, and streamflow analysis to describe landscape dynamics and investigate the large-scale effects of changing land use and land cover. The picture is quite complex. Instead of uniform woody plant encroachment, shrubs have undergone marked decrease in some areas through management efforts. As a result, woody plants have experienced up to a 100% increase in one watershed compared with a 65% decline in another. This accompanies a nearly 85% abandonment of cropland across the area over the last 75 years. While streamflow appears primarily to remain driven by rainfall events, erosion and sedimentation of downstream reservoirs have great implications for water resources. Radioisotope sediment tracers indicate a doubling in sediment yield in certain watersheds while others have displayed a near halt in sediment production. These are largely tied to the dynamic relationship between herbaceous, bare ground, and woody plant cover in different watersheds as well as the proliferation of constructed small ponds, which have increased in number up to 700%. Understanding the dynamics of water and sediment yield through this approach may play a major role in informing rangeland and water resource management at large scales.
Risk assessment of watershed erosion at Naesung Stream, South Korea.
Ji, Un; Velleux, Mark; Julien, Pierre Y; Hwang, Manha
2014-04-01
A three-tiered approach was used to assess erosion risks within the Nakdong River Basin in South Korea and included: (1) a screening based on topography and land use; (2) a lumped parameter analysis using RUSLE; and (3) a detailed analysis using TREX, a fully distributed watershed model. These tiers span a range of spatial and temporal scales, with each tier providing increasing detail and resolution. The first two tiers were applied to the entire Nakdong River Basin and the Naesung Stream watershed was identified as having the highest soil erosion risk and potential for sedimentation problems. For the third tier, the TREX watershed model simulated runoff, channel flow, soil erosion, and stream sediment transport in the Naesung Stream watershed at very high resolution. TREX was calibrated for surface flows and sediment transport, and was used to simulate conditions for a large design storm. Highly erosive areas were identified along ridgelines in several headwater areas, with the northeast area of Songriwon having a particularly high erosion potential. Design storm simulations also indicated that sediment deposition of up to 55 cm could occur. Copyright © 2014 Elsevier Ltd. All rights reserved.
Applications of remote sensing to watershed management
NASA Technical Reports Server (NTRS)
Rango, A.
1975-01-01
Aircraft and satellite remote sensing systems which are capable of contributing to watershed management are described and include: the multispectral scanner subsystem on LANDSAT and the basic multispectral camera array flown on high altitude aircraft such as the U-2. Various aspects of watershed management investigated by remote sensing systems are discussed. Major areas included are: snow mapping, surface water inventories, flood management, hydrologic land use monitoring, and watershed modeling. It is indicated that technological advances in remote sensing of hydrological data must be coupled with an expansion of awareness and training in remote sensing techniques of the watershed management community.
Mitigating the effects of landscape development on streams in urbanizing watersheds
Hogan, Dianna M.; Jarnagin, S. Taylor; Loperfido, John V.; Van Ness, Keith
2013-01-01
This collaborative study examined urbanization and impacts on area streams while using the best available sediment and erosion control (S&EC) practices in developing watersheds in Maryland, United States. During conversion of the agricultural and forested watersheds to urban land use, land surface topography was graded and vegetation was removed creating a high potential for sediment generation and release during storm events. The currently best available S&EC facilities were used during the development process to mitigate storm runoff water quality, quantity, and timing before entering area streams. Detailed Geographic Information System (GIS) maps were created to visualize changing land use and S&EC practices, five temporal collections of LiDAR (light detection and ranging) imagery were used to map the changing landscape topography, and streamflow, physical geomorphology, and habitat data were used to assess the ability of the S&EC facilities to protect receiving streams during development. Despite the use of the best available S&EC facilities, receiving streams experienced altered flow, geomorphology, and decreased biotic community health. These impacts on small streams during watershed development affect sediment and nutrient loads to larger downstream aquatic ecosystems such as the Chesapeake Bay.
Hydrologic response of the Crow Wing Watershed, Minnesota, to mid-Holocene climate change
Person, M.; Roy, P.; Wright, H.; Gutowski, W.; Ito, E.; Winter, T.; Rosenberry, D.; Cohen, D.
2007-01-01
In this study, we have integrated a suite of Holocene paleoclimatic proxies with mathematical modeling in an attempt to obtain a comprehensive picture of how watersheds respond to past climate change. A three-dimensional surface-water-groundwater model was developed to assess the effects of mid-Holocene climate change on water resources within the Crow Wing Watershed, Upper Mississippi Basin in north central Minnesota. The model was first calibrated to a 50 yr historical record of average annual surface-water discharge, monthly groundwater levels, and lake-level fluctuations. The model was able to reproduce reasonably well long-term historical records (1949-1999) of water-table and lake-level fluctuations across the watershed as well as stream discharge near the watershed outlet. The calibrated model was then used to reproduce paleogroundwater and lake levels using climate reconstructions based on pollen-transfer functions from Williams Lake just outside the watershed. Computed declines in mid-Holocene lake levels for two lakes at opposite ends of the watershed were between 6 and 18 m. Simulated streamflow near the outlet of the watershed decreased to 70% of modern average annual discharge after ???200 yr. The area covered by wetlands for the entire watershed was reduced by ???16%. The mid-Holocene hydrologic changes indicated by these model results and corroborated by several lake-core records across the Crow Wing Watershed may serve as a useful proxy of the hydrologic response to future warm, dry climatic forecasts (ca. 2050) made by some atmospheric general-circulation models for the glaciated Midwestern United States. ?? 2007 Geological Society of America.
NASA Astrophysics Data System (ADS)
Zhang, S.; Tang, L.
2007-05-01
Panjiakou Reservoir is an important drinking water resource in Haihe River Basin, Hebei Province, People's Republic of China. The upstream watershed area is about 35,000 square kilometers. Recently, the water pollution in the reservoir is becoming more serious owing to the non-point pollution as well as point source pollution on the upstream watershed. To effectively manage the reservoir and watershed and develop a plan to reduce pollutant loads, the loading of non-point and point pollution and their distribution on the upstream watershed must be understood fully. The SWAT model is used to simulate the production and transportation of the non-point source pollutants in the upstream watershed of the Panjiakou Reservoir. The loadings of non-point source pollutants are calculated for different hydrologic years and the spatial and temporal characteristics of non-point source pollution are studied. The stream network and topographic characteristics of the stream network and sub-basins are all derived from the DEM by ArcGIS software. The soil and land use data are reclassified and the soil physical properties database file is created for the model. The SWAT model was calibrated with observed data of several hydrologic monitoring stations in the study area. The results of the calibration show that the model performs fairly well. Then the calibrated model was used to calculate the loadings of non-point source pollutants for a wet year, a normal year and a dry year respectively. The time and space distribution of flow, sediment and non-point source pollution were analyzed depending on the simulated results. The comparison of different hydrologic years on calculation results is dramatic. The loading of non-point source pollution in the wet year is relatively larger but smaller in the dry year since the non-point source pollutants are mainly transported through the runoff. The pollution loading within a year is mainly produced in the flood season. Because SWAT is a distributed model, it is possible to view model output as it varies across the basin, so the critical areas and reaches can be found in the study area. According to the simulation results, it is found that different land uses can yield different results and fertilization in rainy season has an important impact on the non- point source pollution. The limitations of the SWAT model are also discussed and the measures of the control and prevention of non- point source pollution for Panjiakou Reservoir are presented according to the analysis of model calculation results.
NASA Astrophysics Data System (ADS)
Kumar, T. Jeyavel Raja; Balasubramanian, A.; Kumar, R. S.; Dushiyanthan, C.; Thiruneelakandan, B.; Suresh, R.; Karthikeyan, K.; Davidraju, D.
2016-06-01
Aquifer performance was tested in 24 locations to assess the groundwater potential of the hard rock terrain in the Chittar-Uppodai watershed of the Tambaraparani River basin. Geologically, the area consists of biotite gneiss, charnockite, and quartzite. The aquifer characteristics, such as transmissivity ( T), the storage coefficient, specific capacity, optimum yield, and the recovery rate were calculated. The drawdown transmissivity was determined using Jacob's straight-line method, while the recovery transmissivity was determined by the Theis method. The drawdown transmissivity was low in the western areas, particularly at Kadayanallur, and was higher in the other areas. The recovery transmissivity was high in the western area, and, with the exception of Gangaikondan, was low at other locations. The assessment indicates that there is groundwater potential in the western part of the study area because of favorable results for recovery drawdown, aquifer thickness, and specific capacity.
Hydrologic data for the Obed River watershed, Tennessee
Knight, Rodney R.; Wolfe, William J.; Law, George S.
2014-01-01
The Obed River watershed drains a 520-square-mile area of the Cumberland Plateau physiographic region in the Tennessee River basin. The watershed is underlain by conglomerate, sandstone, and shale of Pennsylvanian age, which overlie Mississippian-age limestone. The larger creeks and rivers of the Obed River system have eroded gorges through the conglomerate and sandstone into the deeper shale. The largest gorges are up to 400 feet deep and are protected by the Wild and Scenic Rivers Act as part of the Obed Wild and Scenic River, which is managed by the National Park Service. The growing communities of Crossville and Crab Orchard, Tennessee, are located upstream of the gorge areas of the Obed River watershed. The cities used about 5.8 million gallons of water per day for drinking water in 2010 from Lake Holiday and Stone Lake in the Obed River watershed and Meadow Park Lake in the Caney Fork River watershed. The city of Crossville operates a wastewater treatment plant that releases an annual average of about 2.2 million gallons per day of treated effluent to the Obed River, representing as much as 10 to 40 percent of the monthly average streamflow of the Obed River near Lancing about 35 miles downstream, during summer and fall. During the past 50 years (1960–2010), several dozen tributary impoundments and more than 2,000 small farm ponds have been constructed in the Obed River watershed. Synoptic streamflow measurements indicate a tendency towards dampened high flows and slightly increased low flows as the percentage of basin area controlled by impoundments increases.
Banta, J. Ryan; Ockerman, Darwin J.
2014-01-01
Suspended sediment in rivers and streams can play an important role in ecological health of rivers and estuaries and consequently is an important issue for water-resource managers. To better understand suspended-sediment loads and transport in a watershed, the U.S. Geological Survey (USGS), in cooperation with the San Antonio River Authority, developed a Hydrological Simulation Program—FORTRAN model to simulate hydrologic conditions and suspended-sediment loads during 2000–12 for four watersheds, which comprise the overall study area in the San Antonio River Basin (hereinafter referred to as the “USGS–2014 model”). The study area consists of approximately 2,150 square miles encompassing parts of Bexar, Guadalupe, Wilson, Karnes, DeWitt, Goliad, Victoria, and Refugio Counties. The USGS–2014 model was calibrated for hydrology and suspended sediment for 2006–12. Overall, model-fit statistics and graphic evaluations from the calibration and testing periods provided multiple lines of evidence indicating that the USGS–2014 model simulations of hydrologic and suspended-sediment conditions were mostly “good” to “very good.” Model simulation results indicated that approximately 1,230 tons per day of suspended sediment exited the study area and were delivered to the Guadalupe River during 2006–12, of which approximately 62 percent originated upstream from the study area. Sample data and simulated model results indicate that most of the suspended-sediment load in the study area consisted of silt- and clay-sized particles (less than 0.0625 millimeters). The Cibolo Creek watershed was the largest contributor of suspended sediment from the study area. For the entire study area, open/developed land and cropland exhibited the highest simulated soil erosion rates; however, the largest contributions of sediment (by land-cover type) were pasture and forest/rangeland/shrubland, which together composed approximately 80 percent of the land cover of the study area and generated about 70 percent of the suspended-sediment load from the study area.
Estimating Precipitation Input to a Watershed by Combining Gauge and Radar Derived Observations
NASA Astrophysics Data System (ADS)
Ercan, M. B.; Goodall, J. L.
2011-12-01
One challenge in creating an accurate watershed model is obtaining estimates of precipitation intensity over the watershed area. While precipitation measurements are generally available from gauging stations and radar instruments, both of these approaches for measuring precipitation have strengths and weakness. A typical way of addressing this challenge is to use gauged precipitation estimates to calibrate radar based estimates, however this study proposes a slightly different approach in which the optimal daily precipitation value is selected from either the gauged or the radar estimates based on the observed streamflow for that day. Our proposed approach is perhaps most relevant for cases of modeling watersheds that do not have a nearby precipitation gauge, or for regions that experience convective storms that are often highly spatially variable. Using the Eno River watershed located in Orange County, NC, three different precipitation datasets were created to predict streamflow at the watershed outlet for the time period 2005-2010 using the Soil and Water Assessment Tool (SWAT): (1) estimates based on only precipitation gauging stations, (2) estimates based only on gauged-corrected radar observations, and (3) the combination of precipitation estimates from the gauge and radar data determined using our proposed approach. The results show that the combined precipitation approach significantly improves streamflow predictions (Nash-Sutcliffe Coefficient, E = 0.66) when compared to the gauged estimates alone (E = 0.47) and the radar based estimates alone (E = 0.45). Our study was limited to one watershed, therefore additional studies are needed to control for factors such as climate, ecology, and hydrogeology that will likely influence the results of the analysis.
Li, Tong; Chu, Chunli; Zhang, Yinan; Ju, Meiting; Wang, Yuqiu
2017-06-29
Eutrophication is a major problem in China. To combat this issue, the country needs to establish water quality targets, monitoring systems, and intelligent watershed management. This study explores a new watershed management method. Water quality is first assessed using a single factor index method. Then, changes in total nitrogen/total phosphorus (TN/TP) are analyzed to determine the limiting factor. Next, the study compares the eutrophication status of two water function districts, using a comprehensive nutritional state index method and geographic information system (GIS) visualization. Finally, nutrient sources are qualitatively analyzed. Two functional water areas in Tianjin, China were selected and analyzed: Qilihai National Wetland Nature Reserve and Yuqiao Reservoir. The reservoir is a drinking water source. Results indicate that total nitrogen (TN) and total phosphorus (TP) pollution are the main factors driving eutrophication in the Qilihai Wetland and Yuqiao Reservoir. Phosphorus was the limiting factor in the Yuqiao Reservoir; nitrogen was the limiting factor in the Qilihai Wetland. Pollution in Qilihai Wetland is more serious than in Yuqiao Reservoir. The study found that external sources are the main source of pollution. These two functional water areas are vital for Tianjin; as such, the study proposes targeted management measures.
Urban Stream Burial Increases Watershed-Scale Nitrate Export.
Beaulieu, Jake J; Golden, Heather E; Knightes, Christopher D; Mayer, Paul M; Kaushal, Sujay S; Pennino, Michael J; Arango, Clay P; Balz, David A; Elonen, Colleen M; Fritz, Ken M; Hill, Brian H
2015-01-01
Nitrogen (N) uptake in streams is an important ecosystem service that reduces nutrient loading to downstream ecosystems. Here we synthesize studies that investigated the effects of urban stream burial on N-uptake in two metropolitan areas and use simulation modeling to scale our measurements to the broader watershed scale. We report that nitrate travels on average 18 times farther downstream in buried than in open streams before being removed from the water column, indicating that burial substantially reduces N uptake in streams. Simulation modeling suggests that as burial expands throughout a river network, N uptake rates increase in the remaining open reaches which somewhat offsets reduced N uptake in buried reaches. This is particularly true at low levels of stream burial. At higher levels of stream burial, however, open reaches become rare and cumulative N uptake across all open reaches in the watershed rapidly declines. As a result, watershed-scale N export increases slowly at low levels of stream burial, after which increases in export become more pronounced. Stream burial in the lower, more urbanized portions of the watershed had a greater effect on N export than an equivalent amount of stream burial in the upper watershed. We suggest that stream daylighting (i.e., uncovering buried streams) can increase watershed-scale N retention.
Urban Stream Burial Increases Watershed-Scale Nitrate Export
Beaulieu, Jake J.; Golden, Heather E.; Knightes, Christopher D.; Mayer, Paul M.; Kaushal, Sujay S.; Pennino, Michael J.; Arango, Clay P.; Balz, David A.; Elonen, Colleen M.; Fritz, Ken M.; Hill, Brian H.
2015-01-01
Nitrogen (N) uptake in streams is an important ecosystem service that reduces nutrient loading to downstream ecosystems. Here we synthesize studies that investigated the effects of urban stream burial on N-uptake in two metropolitan areas and use simulation modeling to scale our measurements to the broader watershed scale. We report that nitrate travels on average 18 times farther downstream in buried than in open streams before being removed from the water column, indicating that burial substantially reduces N uptake in streams. Simulation modeling suggests that as burial expands throughout a river network, N uptake rates increase in the remaining open reaches which somewhat offsets reduced N uptake in buried reaches. This is particularly true at low levels of stream burial. At higher levels of stream burial, however, open reaches become rare and cumulative N uptake across all open reaches in the watershed rapidly declines. As a result, watershed-scale N export increases slowly at low levels of stream burial, after which increases in export become more pronounced. Stream burial in the lower, more urbanized portions of the watershed had a greater effect on N export than an equivalent amount of stream burial in the upper watershed. We suggest that stream daylighting (i.e., uncovering buried streams) can increase watershed-scale N retention. PMID:26186731
Jung, Kwang-Wook; Yoon, Choon-G; Jang, Jae-Ho; Kong, Dong-Soo
2008-01-01
Effective watershed management often demands qualitative and quantitative predictions of the effect of future management activities as arguments for policy makers and administration. The BASINS geographic information system was developed to compute total maximum daily loads, which are helpful to establish hydrological process and water quality modeling system. In this paper the BASINS toolkit HSPF model is applied in 20,271 km(2) large watershed of the Han River Basin is used for applicability of HSPF and BMPs scenarios. For proper evaluation of watershed and stream water quality, comprehensive estimation methods are necessary to assess large amounts of point source and nonpoint-source (NPS) pollution based on the total watershed area. In this study, The Hydrological Simulation Program-FORTRAN (HSPF) was estimated to simulate watershed pollutant loads containing dam operation and applied BMPs scenarios for control NPS pollution. The 8-day monitoring data (about three years) were used in the calibration and verification processes. Model performance was in the range of "very good" and "good" based on percent difference. The water-quality simulation results were encouraging for this large sizable watershed with dam operation practice and mixed land uses; HSPF proved adequate, and its application is recommended to simulate watershed processes and BMPs evaluation. IWA Publishing 2008.
Estimation of sediment inflows to Lake Tuscaloosa, Alabama, 2009-11
Lee, K.G.
2013-01-01
The U.S. Geological Survey, in cooperation with the City of Tuscaloosa, evaluated the concentrations, loads, and yields of suspended sediment in the tributaries to Lake Tuscaloosa in west-central Alabama, from October 1, 2008, to January 31, 2012. The collection and analysis of these data will facilitate the comparison with historical data, serve as a baseline for future sediment-collection efforts, and help to identify areas of concern. Lake Tuscaloosa, at the reservoir dam, receives runoff from a drainage area of 423 square miles (mi2). Basinwide in 2006, forested land was the primary land cover (68 percent). Comparison of historical imagery with the National Land Cover Database (2001 and 2006) indicated that the greatest temporal land-use change was timber harvest. The land cover in 2006 was indicative of this change, with shrub/scrub land (12 percent) being the secondary land use in the basin. Agricultural land use (10 percent) was represented predominantly by hay and pasture or grasslands. Urban land use was minimal, accounting for 4 percent of the entire basin. The remaining 6 percent of the basin has a land use of open water or wetlands. Storm and monthly suspended-sediment samples were collected from seven tributaries to Lake Tuscaloosa: North River, Turkey Creek, Binion Creek, Pole Bridge Creek, Tierce Creek, Carroll Creek, and Brush Creek. Suspended-sediment concentrations and streamflow measurements were statistically analyzed to estimate annual suspended-sediment loads and yields from each of these contributing watersheds. Estimated annual suspended-sediment yields in 2009 were 360, 540, and 840 tons per square mile (tons/mi2) at the North River, Turkey Creek, and Carroll Creek streamflow-gaging stations, respectively. Estimated annual suspended-sediment yields in 2010 were 120 and 86 tons/mi2 at the Binion Creek and Pole Bridge Creek streamflow-gaging stations, respectively. Estimated annual suspended-sediment yields in 2011 were 190 and 300 tons/mi2 at the Tierce Creek and Brush Creek streamflow-gaging stations, respectively. The North River watershed at the streamflow-gaging station contributes 53 percent of the drainage area for Lake Tuscaloosa. A previous study in the 1970s analyzed streamflow and historical suspended-sediment samples to estimate a long-term average suspended-sediment yield of 300 tons per year per square mile in the North River watershed. Analysis of data collected in the North River watershed during the 2009 water year (October 2008 to September 2009) estimated a sediment yield of 360 tons/mi2. The North River watershed, a major portion of the Lake Tuscaloosa drainage basin, has not experienced a substantial increase in sedimentation rates. During the 2009 water year, the Turkey Creek watershed (6.16 mi2) and the Carroll Creek watershed (20.9 mi2) produced greater suspended-sediment yields than the North River watershed but contribute a much smaller drainage area to Lake Tuscaloosa. Aerial photography and bathymetric surveys indicate that Carroll Creek has experienced increased sediment deposition in the upstream portions of the channel. Carroll Creek is also the only watershed in the current study that has a substantial percentage (11 percent) of urban
Alber, Adrien; Piégay, Hervé
2017-11-01
An increased awareness by river managers of the importance of river channel migration to sediment dynamics, habitat complexity and other ecosystem functions has led to an advance in the science and practice of identifying, protecting or restoring specific erodible corridors across which rivers are free to migrate. One current challenge is the application of these watershed-specific goals at the regional planning scales (e.g., the European Water Framework Directive). This study provides a GIS-based spatial analysis of the channel migration rates at the regional-scale. As a case study, 99 reaches were sampled in the French part of the Rhône Basin and nearby tributaries of the Mediterranean Sea (111,300 km 2 ). We explored the spatial correlation between the channel migration rate and a set of simple variables (e.g., watershed area, channel slope, stream power, active channel width). We found that the spatial variability of the channel migration rates was primary explained by the gross stream power (R 2 = 0.48) and more surprisingly by the active channel width scaled by the watershed area. The relationship between the absolute migration rate and the gross stream power is generally consistent with the published empirical models for freely meandering rivers, whereas it is less significant for the multi-thread reaches. The discussion focused on methodological constraints for a regional-scale modelling of the migration rates, and the interpretation of the empirical models. We hypothesize that the active channel width scaled by the watershed area is a surrogate for the sediment supply which may be a more critical factor than the bank resistance for explaining the regional-scale variability of the migration rates. Copyright © 2016 Elsevier Ltd. All rights reserved.
Nutrients discharged to the Mississippi River from eastern Iowa watersheds, 1996-1997
Becher, Kent D.; Schnoebelen, Douglas J.; Akers, Kimberlee K.
2000-01-01
The introduction of nutrients from chemical fertilizer, animal manure, wastewater, and atmospheric deposition to the eastern Iowa environment creates a large potential for nutrient transport in watersheds. Agriculture constitutes 93 percent of all land use in eastern Iowa. As part of the U.S. Geological Survey National Water Quality Assessment Program, water samples were collected (typically monthly) from six small and six large watersheds in eastern Iowa between March 1996 and September 1997. A Geographic Information System (GIS) was used to determine land use and quantify inputs of nitrogen and phosphorus within the study area. Streamliow from the watersheds is to the Mississippi River. Chemical fertilizer and animal manure account for 92 percent of the estimated total nitrogen and 99.9 percent of the estimated total phosphorus input in the study area. Total nitrogen and total phosphorus loads for 1996 were estimated for nine of the 12 rivers and creeks using a minimum variance unbiased estimator model. A seasonal pattern of concentrations and loads was observed. The greatest concentrations and loads occur in the late spring to early summer in conjunction with row-crop fertilizer applications and spring nmoff and again in the late fall to early winter as vegetation goes into dormancy and additional fertilizer is applied to row-crop fields. The three largest rivers in eastern Iowa transported an estimated total of 79,000 metric tons of total nitrogen and 6,800 metric tons of total phosphorus to the Mississippi River in 1996. The estimated mass of total nitrogen and total phosphorus transported to the Mississippi River represents about 19 percent of all estimated nitrogen and 9 percent of all estimated phosphorus input to the study area.