Effects of wildfire in the mountainous terrain of southeast Arizona [electronic resource] : empirical formulas to estimate from 1-year through 10-year peak discharge from post-burn watersheds / William B. Reed and Mike Schaffner.
Imprint
Salt Lake City, Utah : U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Weather Service, Scientific Services Division, Western Region, [2008]
"In the desert southwest of the United States, wildfire alters the hydrologic response of watersheds greatly increasing the magnitudes and frequency of flash floods. The NOAA National Weather Service is tasked with the issuance of flash flood warnings to save life and property. Tools that allow the weather forecast offices to quickly access the peak flow magnitude and flood potential from burned areas is highly desirable. The application of readily available topographic and burn severity data make this possible through a series of empirical equations. This paper describes the development of several empirical equations to predict post-burn peak flows expected in response to forecast rainfall events with known return interval. These equations work well for the documented watersheds: the lowest adjusted R-squared value is 0.94. The cornerstone of their predictive usefulness is a multivariate runoff index. The index incorporates four easily determined factors; the sum of high and moderate burn severity area (the hyper-effective drainage area), the average basin elevation, the modified channel relief ratio, and the return interval of forecast rainfall. The new equations predict the runoff from the hyper-effective drainage area. To obtain the runoff from the entire watershed, the runoff from the remaining watershed (calculated using standard methods) is added to the results"--Abstract.