Predicting Peak Discharge Uncertainty from Standard Methods Due To Variability in Hydrologic Characteristics
Abstract
This study examines the combined effects of method selection and corresponding hydrologic parameter variability on the estimated peak discharges. Five standard methods are used to estimate peak discharges from 20 watersheds in Maryland ranging in size from 0.02 sq km to 0.20 sq km. Models to be investigated are U.S. Geological Survey Regression Equations, NRCS Unit Hydrograph, TR-55, TR-20 without sub-division, and TR-20 with sub-division. A geographic information system based hydrologic analysis package is used to extract hydrologic model parameters from DEMs, landuse/landcover and soils data. This study also investigates the effects of data source and the aggregation of parameter uncertainty (i.e., drainage area, flow length, relief, slope, NRCS runoff curve numbers, and time of concentration estimates). Individual and combined effects resulting for each model are presented. Results are also compared to flood frequency distributions determined from USGS annual peak discharges.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.H21F1121W
- Keywords:
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- 1873 HYDROLOGY / Uncertainty assessment;
- 1879 HYDROLOGY / Watershed