2-Regional flood frequency approach estimation of flood peaks for Mahi and Sabarmati basin (sub-Zone 3a)

Abstract

Knowledge of magnitude of flood related to its problem frequency of recurrence is necessary for rational and economical design of water-way and foundations of bridges and appurtenances. In this Paper hydrometeorologically homogenous Mahi and Sabarmati Basin, Sub-zone 3 (a) with semi-arid climate has been selected for study Tweleve bridge sites with catchment areas varying from 19 km2 to 1094 km2 with availability of annual flood peaks for the period from 1961 to 1985, have been considered for probability studies. Making use of this data and utilizing the regional frequency approach, a dimensionless curve giving the ratios of return period flood peaks to mean annual flood peak (Q2.33) and a correlation between mean annual flood peak and relevant catchment characteristics have been developed using linear regression technique.