HR: 0800h
AN: H11C-0665    [Abstracts]
TI: Baseflow Recession Model Dependence on Drainage Basin Spatial Characteristics
AU: * Eli, R N
EM: robert.eli@mail.wvu.edu
AF: W West Virginia University, Box 6103, Department of Civil and Environmental Engineering, Morgantown, WV 26506- 6103, United States
AU: Lamont, S J
EM: sam.lamont@mail.wvu.edu
AF: West Virginia University, Box 6108, Natural Resource Analysis Center, Morgantown, WV 26506-6108, United States
AU: Fletcher, J J
EM: jerry.fletcher@mail.wvu.edu
AF: West Virginia University, Box 6108, Natural Resource Analysis Center, Morgantown, WV 26506-6108, United States
AB: The Natural Resource Analysis Center (NRAC) at West Virginia University (WVU) has developed an ArcGIS 9.x extension application called the Watershed Characterization and Modeling System (WCMS). WCMS is a GIS- based watershed analysis tool currently used by permit writers in the West Virginia Department of Environmental Protection (WVDEP) Divisions of Water Resources and Mining and Reclamation. WCMS utilizes drainage basin subdivisions consistent with the 1:24,000 NHD (National Hydrography Dataset) stream segments. The recent addition of the U.S. Environmental Protection Agency surface water model HSPF (Hydrological Simulation Program – FORTRAN ) to WCMS provides surface water quality modeling capabilities. Calibration of HSPF to representative drainage basins uncovered inadequacies in the groundwater outflow modeling component that produces recessionary streamflow. As is the case with many popular watershed models, HSPF includes its groundwater storage and outflow components within each subbasin water budget through the use of a relatively simple storage-outflow function. An examination of the groundwater flow behavior typical in mountainous West Virginia drainage basins shows that stream segment groundwater outflows have their source both within the immediate subbasin and from adjacent and upstream subbasins. Therefore, each subbasin water budget must include groundwater inputs from other subbasins to which it is hydraulically linked. To gain insight into these linkages, and to identify spatially dependent parameters important in modeling subbasin recessionary outflows, numerical experiments have been conducted on a representative drainage basin using the USGS MODFLOW groundwater model. The results support the conclusion that subbasin stream segment outflows partially originate from groundwater within adjacent and upstream subbasins, and that spatially dependent measures such as flow path distances and groundwater storage distributions within this hydraulically connected region are just as relevant as the local subbasin groundwater parameters in determining baseflow recession characteristics.
DE: 1829 Groundwater hydrology
DE: 1830 Groundwater/surface water interaction
DE: 1847 Modeling
DE: 1849 Numerical approximations and analysis
SC: Hydrology [H]
MN: 2007 Fall Meeting