SIMULATION OF STREAM FLOWS FOR FORESTED WATERSHEDS OF WESTERN GHATS

Abstract

The Western Ghat catchments falling within the state of Kerala form the study area. The objective was to simulate low flow indices and daily flows. Low flow studies were conducted with a view to formulate predictive regression equations for low flow indices like 75 percent dependable one day summer flow and mean annual one day minimum flow. Various catchment characteristics like catchment area, base flow index, main stream length, annual averts .e rainfall and area under forests etc. were assessed for eiLht sub-basins and used in developing the equations. It set of equations, taking three catchment parameters at a time, was developed for each low flow index under consideration. These equations can be put into use in any other similar sub-basin with a fair degree of accuracy. However, it was evident from the study that the quality of the equations can be sub-stantially improved by enlarging the data base. Daily flows were simulated for Aryanadu sub-basin of Karcmana river using the Tank Model. First of all the model was calibrated using observed precipitation and discharge values for the yLars 1977 and 1978. Then the model was tested for the ye^.r 1979.