Ecology, Environment and Conservation Paper

SIMULATION AND PREDICTION OF GROUNDWATER DYNAMICSIN NAGARJUNA SAGAR RIGHT CANAL (NSRC) COMMAND FORNORMAL AND EXTREME GROUNDWATER RECHARGE CONDITIONS

R. Ganesh Babu. G. Ravi Babu, A. Mani, P. Prasuna Rani and V. Srinivasa Rao

Abstract

Groundwater Modeling is the best tool to optimize the different combinations and to select the bestcombination for sustainable groundwater management. Using computer models, best solution or scenariocan optimize by creating model with real conditions. In this study, computer model Visual MODFLOWwas applied to Nagarjuna Sagar Right Canal Command area to simulate the groundwater dynamics. Thenet area irrigated under Nagarjuna Sagar Right Canal is 4.75 lakh ha. The aquifer properties of variouslayers and boundary conditions were fed in to the model as input for calibration and validation of themodel. After calibration and validation, the model was used to predict the groundwater dynamics in thestudy area using different recharge scenarios. The validated groundwater model was used to predict thegroundwater levels in the study area for the years 2020, 2030 and 2040 with different recharge scenarios.Global climate model was used to generate future weather data. MarkSim developed by the InternationalCentre for Tropical Agriculture (CIAT) was used to generate the weather parameters like maximum andminimum temperatures for the years 2020, 2030 and 2040. The different recharge scenarios with average,lowest and highest recharge over the study period and projected evapotranspiration have been used andrevealed that the groundwater levels increase with the increase in recharge and decreases with the decreasein recharge. The results revealed that the groundwater depleted area would decrease with the highestrecharge scenario and it would increase with the lowest recharge scenario in future. The deeper groundwatertable would be expected in future at Chimakurthy and Thalluru villages of Prakasam district and Karempudiand Piduguralla villages of Guntur district in the study area. This condition may be due to the excessutilization of groundwater which is less than the groundwater recharge in particular villages. Theconstruction of rainwater harvesting structures for artificial groundwater recharge in those areas should becarried out immediately.