Abstract

Rainfall intensity-duration-return period equations and nomographs for various stations are required for designing soil conservation and runoff disposal structures and also for planning flood control projects. Such relationships and nomographs for the state of Tamil Nadu were developed during 1978 for few stations namely Madras (Chennai), Tiruchirapalli and Kodaikanal. Presently, long period self recording rainfall data for 18 stations of Tamil Nadu State have been obtained from Indian Meteorological Department, Pune. Based on the data, the intensity-duration-return period equations and nomographs for all the 18 stations have been developed and discussed along with the general equation and nomograph for the State of Tamil Nadu.

Keywords: Rainfall intensity, Return period, Recurrrence interval, Nomograph, Run-off disposal