Rainfall-runoff relationship based on the model of runoff formation at the natural storage

Abstract

An attempt is mad~ to establish a relationship between rainfall and runoff. The basic input data are (i) rainfall, (ii) run off and (iii) evapotranspiration. The moisture content prior to rainfall under consideration and after the termination of rainfall is computed by water balance technique this method is applied in small agricultural catchments in Soil Conservation Research Farm at Ballary, Karnataka, which is categorised its semiarid zone of black soil region. The relationship between rainfall and runoff under different initial moisture content and rainfall intensities are found out. Attempts are also made to get relationship between moisture condition of the catchment after the end of rainfall and runoff with rainfall intensities as an additional factor. The estimated runoff obtained from various equations are compared with the observed runoff. The rainfall-runoff relationship with initial moisture content as third parameter gives encouraging results for estimation of runoff.