CS(AR)-25/99-2000 : Regional Model for annual runoff estimation

Abstract

Successful planning and implementation of water resources projects require reliable data on volumetric runoff. Given the financial constraints it is not feasible to have discharge stations in all the river basins of interest. Therefore regional rainfall runoff models are preferred. The utility of such models can be improved if rainfall — runoff models for different regions are developed with data specific to the regions. An attempt has been made in the present study to develop a seasonal rainfall — runoff model for the Saurashtra region and also parts of Narmada river basin. A constrained simple bivariate linear regression model, a constrained bivariate non-linear model and a multivariate linear regression model with hydrometeorological data pertaining to 12 sub-basins of Saurashtra region have been developed. The efficiency of the models have been evaluated as 61%, 66% and 65% respectively. Considering the efficiency of the models discussed above, the bivariate non-linear model has a distinct advantage over the multivariate model as it requires only the rainfall data but has an efficiency comparable to that of the multivariate model that requires pan-evaporation data in addition to rainfall data.