Civil & Environmental Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/2221
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Item MODELING URBAN FLOODING IN THE TIBER BRANCH WATERSHED, ELLICOTT CITY, MARYLAND, USING PCSWMM(2020) Walcott, Cadijah; Brubaker, Kaye; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Urban flooding — due to land cover change, inadequate drainage networks, and increased precipitation — exacerbates communities’ economic and social vul¬nerabilities. A detailed watershed model can help communities identify weak portions of the drainage network and design resolutions. This research details the development of a comprehensive model of the Tiber Branch Watershed in Ellicott City, Maryland, to reproduce observed depth in the Hudson Branch tributary using PCSWMM (a commercial version of the U.S. Environmental Protection Agency’s Storm Water Management Model). The 2,434.8-acre watershed comprises 8,821 PCSWMM objects, which were estimated from various raster and vector datasets. Without calibration, the model generally captures the timing and shape of the stage hydrographs but is less successful in simulating event magnitude and receives a R2 of 0.65 and SE/SY of 0.67 for the 43 selected events, collectively. Ultimately, model evaluation was not completed due to a lack of representative rainfall within the watershed.Item Pluvial Flood Risk Estimation Procedure for Small Urban Watersheds(2012) Cone, John Trevor; McCuen, Richard H; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Pluvial flooding, when runoff causes flooding before it reaches a body of water, is a type of flooding that often is overlooked in flood risk studies. This study outlines a general procedure that can be used to model urban pluvial flood scenarios, estimate damages, and quantify pluvial flood risk for microwatersheds (watersheds of a few square miles or less). The model development was accomplished using EPA's SWMM in combination with GIS datasets and analyses. Sensitivity analyses were performed on many model inputs including runoff surface slope, imperviousness, infiltration parameters, and pipe roughness. The overall procedure was tested on a 215-acre sewershed in Washington, DC. The results indicate that pluvial flooding can have serious consequences, even in areas that are not close to existing bodies of water and are at relatively high elevations. The 10-, 100-, and 200-yr rainfall events modeled produced damage estimates of approximately $430,000, $904,000, and $1,093,000, respectively.