Evaluation of Non Damaging Flow for a Set of Upstream Sub Basins in a River System

Abstract

A model for evaluating non damaging flow for a set of sub basins in a river system is presented. Linear Programming technique incorporating multiple inflows routing scheme is employed to evaluate upstream flow conditions necessary for satisfying specified downstream flood flow conditions. Non damaging flow for the sub basins are determined by using river system properties. The model is applied to a river system in India having flows from gauged and ungauged sub basins; flow contributions from the ungauged basins are estimated by using unit hydrograph technique. Peak flow studies involving major and minor sub basins indicate relative importance of the basins in the study area. Results obtained in the study depict variations in the non-damaging flow with the flow in the main channel. Model applications show that for flood with peaks exceeding 7566 m³/s regulating intervening basins only may not lead to safe flow at the downstream section(s). The model allows evaluating effectiveness of controlling the intervening basins in a river system; model applications to a real life river system yield results that are useful in adopting flood control measures for the study area.