Browsing by Author "Schnick, Lori H."
Now showing 1 - 1 of 1
Results Per Page
Sort Options
Item Using a geographic information system (GIS) and the water erosion prediction project model (WEPP) to obtain soil erodibility parameters for predicting sediment yields from urbanizing sub-basins in Montgomery County, Maryland, U.S.A.(University of Delaware, 2005) Schnick, Lori H.A ten year study by Yorke and Herb (1978) described the effects of land use on erosion and runoff from small sub-basins within the Rock Creek and Northwest Branch Anacostia River basins in Montgomery County, Maryland. The urbanized catchment of Lutes Run, located in the southwest corner of the Northwest Branch Anacostia River watershed, was included in the Yorke and Herb study. Sediment yields, runoff rates and other hydrologically significant data were collected for ten years for each effective storm event from temporary monitoring stations located within Lutes Run sub-basin. Storm characteristics were documented every fifteen minutes from a temporary rain gauging station. At various times Lutes Run underwent construction activity and the total area of construction was well documented. ☐ This research was conducted to select model inputs describing erodibility, so that the urbanized landscape can be accurately modeled using the Water Erosion Prediction Project model (WEPP). WEPP was created to model erosion from agricultural, range and forested lands and requires four input files describing land use, soil, climate and slope for each hillslope of the watershed. For greater detail of land use heterogeneity the hillslopes of Lutes Run basin were broken into Overland Flow Elements (OFEs). ☐ A Geographic Information System (GIS) and GIS data were used to obtain and analyze topographic and land use data for the time span of the Yorke and Herb (1978) study. Digital Elevation Models (DEMs) were used to obtain a representative slope profile for each hillslope. Land Use Land Cover data (LULC) and parcel data aided in describing the land use characteristics of each OFE including locations of construction activity. ☐ The WEPP model was calibrated using the data published by Yorke and Herb and from the GIS analysis. Urban and Construction were the two land use classes not represented in the available land management input selections available to the user. Erodibility parameters were selected for urban and construction OFEs. Erodibility parameters were tested so that the predicted sediment yields for each storm would match measured values. Once erodibility values for urban and construction OFEs were determined, they were used in model runs for storms not yet tested to correlate predicted with measured sediment yields. The resulting erodibility values and resulting yields were plotted against measured yields to measure accuracy of the prediction. These erodibility values can then be used to predict future erosion in urbanizing watersheds within the Piedmont Province. ☐ GIS was very useful for topographic analysis and for representing the land use. The WEPP model proved to be very sensitive to variations in storm input. Values obtained for construction and urban erodibility parameters predicted sediment yields with deviations less than 31% of measured values.