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Filters: Contacts: Ali M. Sadeghi (X)

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This posting contains the source climate data used to run the SWAT model in the Tuckahoe and Greensboro subwatersheds of the Choptank River watershed, Maryland.
Categories: Data; Types: Citation; Tags: Choptank, agriculture, water quality
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Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates...
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This posting contains the source crop rotation data used to run the SWAT model in the Tuckahoe and Greensboro subwatersheds of the Choptank River watershed, Maryland. The dataset consists of the following items: Croprotations.zip = Shapefiles of HRU boundaries and crop rotations for Greensboro (GSB) and Tuckahoe (TK) watershed
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This posting contains the stream flow and load data used to run the SWAT model in the Tuckahoe subwatershed of the Choptank River watershed, Maryland.
Categories: Data; Types: Citation; Tags: Choptank, agriculture, water quality
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Excess nutrients and agrochemicals from non-point sources contribute to water quality impairment in the Chesapeake Bay watershed and their loading rates are related to land use, agricultural practices, hydrology, and pollutant fate and transport processes. In this study, monthly baseflow stream samples from 15 agricultural subwatersheds of the Choptank River in Maryland USA (2005 to 2007) were characterized for nutrients, herbicides, and herbicide transformation products. High-resolution digital maps of land use and forested wetlands were derived from remote sensing imagery. Examination of landscape metrics and water quality data, partitioned according to hydrogeomorphic class, provided insight into the fate, delivery,...
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Over 50% of streams in the Chesapeake Bay watershed have been rated as poor or very poor based on the index of biological integrity. The Choptank River estuary, a Bay tributary on the eastern shore, is one such waterway, where corn and soybean production in upland areas of the watershed contribute significant loads of nutrients and sediment to streams. We adopted a novel approach utilizing the relationship between the concentration of nitrate-N and the stable, water-soluble herbicide degradation product MESA {2-[2-ethyl-N-(1-methoxypropan-2-yl)-6-methylanilino]-2-oxoethanesulfonic acid} to distinguish between dilution and denitrification effects on the stream concentration of nitrate-N in agricultural subwatersheds....
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Water quality problems in the Chesapeake Bay Watershed (CBW) are expected to be exacerbated by climate variability and change. However, climate impacts on agricultural lands and resultant nutrient loads into surface water resources are largely unknown. This study evaluated the impacts of climate variability and change on two adjacent watersheds in the Coastal Plain of the CBW, using the Soil and Water Assessment Tool (SWAT) model. We prepared six climate sensitivity scenarios to assess the individual impacts of variations in CO2concentration (590 and 850 ppm), precipitation increase (11 and 21 %), and temperature increase (2.9 and 5.0 °C), based on regional general circulation model (GCM) projections. Further, we...
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Winter cover crops (WCCs) have been widely implemented in the Coastal Plain of the Chesapeake Bay watershed (CBW) due to their high effectiveness at reducing nitrate loads. However, future climate conditions (FCCs) are expected to exacerbate water quality degradation in the CBW by increasing nitrate loads from agriculture. Accordingly, the question remains whether WCCs are sufficient to mitigate increased nutrient loads caused by FCCs. In this study, we assessed the impacts of FCCs on WCC nitrate reduction efficiency on the Coastal Plain of the CBW using Soil and Water Assessment Tool (SWAT) model. Three FCC scenarios (2085 – 2098) were prepared using General Circulation Models (GCMs), considering three Intergovernmnental...
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This posting contains the source stream flow and load data used to run the SWAT model in the Greensboro subwatershed of the Choptank River watershed, Maryland.
Categories: Data; Types: Citation; Tags: Choptank, agriculture, water quality


    map background search result map search result map Metolachlor metabolite (MESA) reveals agricultural nitrate-N fate and transport in Choptank River watershed Greensboro Watershed (Choptank River) stream flow quantity and quality, 1999-2014 Tuckahoe Creek stream flow quantity and quality, 1999-2014 Baseline Climate Data, 2001-2014 Choptank River, MD Predominant Regional Crop Rotations, Choptank River Watershed, MD, derived from Cropland Data Layer Greensboro Watershed (Choptank River) stream flow quantity and quality, 1999-2014 Tuckahoe Creek stream flow quantity and quality, 1999-2014 Baseline Climate Data, 2001-2014 Choptank River, MD Predominant Regional Crop Rotations, Choptank River Watershed, MD, derived from Cropland Data Layer Metolachlor metabolite (MESA) reveals agricultural nitrate-N fate and transport in Choptank River watershed