DOMINANT DISCHARGE IN THE INDUS RIVER FROM DOWNSTREAM OF THE KOTRI BARRAGE DAM

Abstract

Hydraulic data of the Indus River, downstream of Kotri Barrage dam are analyzed. An attempt has been made to determine the dominant discharge, which is defined as that discharge which over a long time period transports the most sediments and could be used to predict the shape of river cross-section. For dominant discharge calculation Wolman and Miller's approach has been applied. Since the transport of sediment concentration could be a more effective variable for forming the shape of the river cross-section, suspended sediment concentration has been introduced, because more than 85% of total load is in suspension. We show in the paper that water discharge Q = 1000 m ³ · s^-1 of water is a frequent discharge and carries maximum sediment load. This discharge we call here the dominant discharge (Qdd) for the Kotri dam cross section.