ISSN:
1752-1688
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Architecture, Civil Engineering, Surveying
,
Geography
Notes:
This paper examines the relationships between measurable watershed hydrologic features, base flow recession rates, and the Q7,10 low flow statistic (the annual minimum seven-day average streamflow occurring once every 10 years on average). Base flow recession constants were determined by analyzing hydrograph recession data from 24 small (〉130 km2), unregulated watersheds across five major physiographic provinces of Pennsylvania, providing a highly variable dataset. Geomorphic, hydrogeologic, and land use parameters were determined for each watershed. The base flow recession constant was found to be most strongly correlated to drainage density, geologic index, and ruggedness number (watershed slope); however, these three parameters are intercorrelated. Multiple regression models were developed for predicting the recession rate, and it was found that only two parameters, drainage density and hydrologic soil group, were required to obtain good estimates of the recession constant. Equations were also developed to relate the recession rates to Q7,10 per unit area, and to the Q7,10/Q50 ratio. Using these equations, estimates of base flow recession rates, Q7,10, and streamflow reduction under drought conditions can be made for small, ungaged basins across a wide range of physiography.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1752-1688.2005.tb03792.x
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