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SIMULATED IMPACTS OF SMALL-SCALE SPATIAL DISTRIBUTION OF IMPERVIOUS AREA ON RUNOFF RESPONSE OF FIELD-SCALE CATCHMENTS
Citation:
ZHANG, Y. SIMULATED IMPACTS OF SMALL-SCALE SPATIAL DISTRIBUTION OF IMPERVIOUS AREA ON RUNOFF RESPONSE OF FIELD-SCALE CATCHMENTS. Presented at American Geophysical Union Joint Assembly, New Orleans, LA, May 23 - 25, 2005.
Impact/Purpose:
To inform the public.
Description:
Impervious surface is known to negatively affect catchment hydrology through both its extent and spatial distribution. In this study, we empirically quantify via model simulations the impacts of different configurations of impervious surface on watershed response to rainfall. An ensemble of spatial distributions of 2-m impervious elements are generated for two small, headwater catchments (ca. 0.5 ha) in the USDA Agricultural Research Service North Appalachian Experimental Watershed (Coshocton, OH). The runoff response of these watersheds under each of the simulated impervious surface scenarios is examined through the simulation of 41 historical rainfall-runoff events over the period of 1975-2003 with the Gridded Surface-Subsurface Hydrologic Analysis (GSSHA) model. The differential dependence of the hydrologic response on fractional coverage, drainage distance to outlet, and hydrologic connectivity of impervious elements is characterized by the distribution of simulated runoff peaks and volumes under the assumption of Hortonian runoff generation. The uncertainties associated with model predicted runoff with the distribution of impervious area within a watershed are further discussed on the basis of the analysis.