Role of Basin Physiography on the Statistical Parameters of Peak Flows
Betül Saf *
Hydraulic Division, Department of Civil Engineering, Pamukkale University, Turkey
*Author to whom correspondence should be addressed.
Abstract
The objective of this study is to integrate frequency and event based rainfall-runoff models in order to derive some conclusions on the role of basin physiography on the frequency distribution of peak flows. Annual peak flow series of the hypothetical basins with alternating physiographic characteristics, such as drainage area, and length and slope of the main channel are generated through a deterministic rainfall-runoff model. Sample statistics and frequency distributions of the generated annual maximum storms of random effective durations and of the resulting peak flow series are investigated. It was found that the average and the standard deviation peak flow decreases as the length of the main course increases, while the average and standard deviation of peak flow increase as the drainage area and harmonic slope increases. Besides variation coefficients and skewness coefficients of the peak flow samples exhibit a random behavior.
Keywords: Synthetic rainfall generation, flood probabilities, rainfall-runoff relationship, unit hydrograph, time of distribution storms, abstraction methods