An investigation into the effect of storm type on precipitation in a small mountain watershed [North Carolina]

• Published in: Water resources research 1979-01, Vol.15 (2), p.298-304
• Main Authors: March, William J., Wallace, James R., Swift, Lloyd W.
• Format: Article
• Language: English
• ISSN: 0043-1397; 1944-7973
• DOI: 10.1029/WR015i002p00298

A set of regression equations relating storm rainfall depth to watershed topography and storm type was derived for the high‐density precipitation network at Coweeta Hydrologic Laboratory. The most general equation predicted storm amounts for an independent test group of gages with an average error of 0.38 cm (0.15 inches). The dependent variable was the ratio of the rainfall at each gage site to the rainfall at a base gage. Predictive variables were topographic slope, aspect, ground elevation at the gage site, and smoothed elevation. The smoothed elevation, which is the elevation the gage would assume if it were on a smooth plane representing the general topography of the terrain, appeared in more equations than any other variable. One equation was calculated for each of six identified storm types, and one equation was calculated with all storms considered together. Overall, the equations which considered storm type were not better predictors of site rainfall than the equation which did not consider storm type. Predictions of storm amounts were closest to measured amounts for storms where the low‐pressure center passed east of Coweeta, while the predictions for the air‐mass or thunderstorm type had the greatest errors. The prediction errors of the equations for warm‐, cold‐, and stationary‐front storm types were intermediate. The small number of tropical storms limited development and testing of equations for that type.