Prediction of peak discharge for small watersheds

The accurate estimate of peak discharge rate is very important for design of drainage system of the watershed. Several studies suggest that the overland resistance coefficient has a vital role in simulating the peak discharge. The overland resistance coefficients for the watersheds were calibrated through the well accepted kinematic wave theory for overland and channel routing of excess rainfall. The present study incorporates the resistance coefficient in the development of peak discharge formula based on regression analysis of the observed data. The Phillip's two term model was used for computing the storm rainfall excess. The proposed event based peak discharge relationship has been arrived at by applying the concept on five watersheds and considering the data of twenty three storm events.