HR: 0800h
AN: H41D-0451    [Abstracts]
TI: Detectability and Uncertaintites in the Interpretation of the Impacts Land Disturbances on Catchment Runoff
AU: Bonta, J
EM: bonta@coshocton.ars.usda.gov
AF: USDA-ARS, North Appalachian Experimental Watershed USDA - Agricultural Research Service 28850 State Rt. 621 Box 488, Coshocton, OH 43812
AU: Shuster, W D
EM: shuster.william@epa.gov
AF: USEPA-NRMRL, 26 W Martin Luther King, Cincinnati, OH 45268
AU: Hicks, N
EM: hicks@mwa.ars.usda.gov
AF: USDA-ARS, North Appalachian Experimental Watershed USDA - Agricultural Research Service 28850 State Rt. 621 Box 488, Coshocton, OH 43812
AU: * Zhang, Y
EM: zhang.yu@epa.gov
AF: USEPA-NRMRL, 26 W Martin Luther King, Cincinnati, OH 45268
AB: Interpretation of the impacts of land disturbances on hydrology are confounded by climate variations. Clear definition of the anthropogenic impacts has been difficult, especially in cases where a clearly defined base line or reference point is absent. This study investigates the detectability of, and uncertainties in the estimates of anthropogenic impacts on runoff, by coupling model-projected episodal runoff under hypothetical disturbed conditions with a temporal sampling method. Selected for this study are two headwater catchments located near Coshocton, OH, where 40 rainfall-runoff episodes were identified in the records of the past 27 years. Gridded Surface-Subsurface Hydrologic Analysis(GSSHA), a distributed hydrologic model, was used to provide simulated runoff during these episodes under a variety of hypothetical scenarios, each corresponding to a unique level and spatial distribution of conceptual impervious areas. Randomly selected subsets of simulated runoff were then joined with observed runoff under natural conditions to construct multiple synthetic time series of runoff episodes to emulate the runoff during different courses of development. Conventional indicators, including runoff ratio, and volume to peak ratio, were applied to gauge the existence and the magnitude of impacts following the addition of impervious area. The detectability of the impacts of land disturbances and the uncertainties in the estimated impacts are analyzed through examining the temporal and inter-scenario variations of the indicator values, respectively. The implications of the results for monitoring and measuring climate and hydrologic changes are discussed.
DE: 1800 HYDROLOGY
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1804 Catchment
DE: 1807 Climate impacts
DE: 1847 Modeling
SC: Hydrology [H]
MN: Fall Meeting 2005