Studies on Water Balance and Groundwater Budgeting in Godawari-Purna Sub-basin

Abstract

The Godawari-Purna sub basin is located between 76°36' to 77°59' E and 19°07' to 19°17' N with an area of 34413.87 ha falls in assured rainfall region. The basin boundary was updated using the updated drainage and terrain information from high resolution satellite data of LISS-IV using GIS tool. Based on the last 30 years rainfall records, the runoff potential was estimated using SCS curve number method. Marathwada region of Maharashtra state has always been a water deficit area which calls for immediate remedial measures to address the critical water resources situation in the region. The entire Godawari-Purna sub basin (GP sub basin) is hard rock terrain. It suffers from growing water scarcity, which is aggravated by frequent droughts. The various water balance components viz. soil moisture storage, ground water recharge and surface storage were estimated for the GP basin. Similarly, the input from the rainfall was also worked out. The various losses such as runoff, evaporation from water bodies were estimated and accordingly the water available in the basin was estimated. The estimated values of ground water recharge were considered for water balance analysis. The surface water storage in each sub basin was estimated considering the water storage area as per satellite image and thus the storage volume was estimated. Combining the soil moisture storage, surface water storage and ground water recharge, water availability was estimated for each sub basin. The surface runoff was estimated by water balance method considering the rainfall volume and losses in each sub basin. Water balance study reflected that sub-catchment No. I, IV, VI and VIII of GP sub basin are under total water deficit and require urgent attention for water management to meet out the water deficit