RAINFALL-RUNOFF MODELLING OF MUTHA RIVER SYSTEM

Abstract

The derivation of relationships between the rainfall over a catchment area and the resulting flow in a river is.a fundamental problem for the hydrologist. In most countries, there are usually. plenty of rainfall records, but more elaborate and expensive stream-flow measurements needed for the assessment- of water resources or of the damaging flood peaks, are often limited and are rarely available for a specific river under investigation. The present work deals with the rainfall-runoff modelling for the TANAJI SAGAR (PANSET) Reservoir watershed of KHADAKWASLA RESERVOIR SYSTEM by applying kinematic wave routing method. .' For the Panset watershed, an approximate unit .hydrograph is computed from the available scanty data which is in the form of tank gauge return. This unit hydrograph is checked by a unit response hydrograph computed by using a kinematic wave model. The unit hydrograph is computed from the flood hydrograph by considering an isolated storm over a certain time period. From the available hourly tank gauge return data, the inflow to the reservoir is computed from the difference in the content during a particular hour which is then converted to cumecs. This data is plotted on the graph paperby averaging the readings over three hours. A bar chart is prepared for this and an average smooth curve is plotted. This gives an -approximate flood hydrograph. From this flood hydrograph an unit hydrograph is computed.