Rainfall Intensity‐Duration‐Frequency Formula for India

Abstract

A rainfall intensity‐duration‐frequency relationship is needed for planning and design of water resources projects. Little information is available about rainfall intensities, in particular for short durations. Data from 80 rain‐gage stations in India were analyzed. Making use of the assumption that general properties of the convective cells that are associated with short‐period (i.e. less than 24 hr) rainfalls are similar in different hydrologic regions, a general relationship for rainfall intensity, duration, and frequency was developed. The correctness of form of the developed relationship was ascertained through its comparison with existing equations and the use of data from different hydrological regions. The relationship proposed herein is found to produce more realistic results for Indian conditions than the ones in vogue. The applicability of this relationship to the data from other countries was checked with the limited data available. The proposed relationship may be used in India for design practices.