Groundwater flow modelling of a micro-watershed in the upland area of East Godavari district, Andhra Pradesh, India

Abstract

In view of the progressive decline of groundwater levels in the majority of non-command upland area in the East Godavari district, Andhra Pradesh state, India, there is an urgency to augment groundwater in the non-command upland areas. Groundwater flow model is constructed for a micro-watershed of 50 km2 namely ‘Konda Kalava watershed’ of ‘Suddegedda river basin’ located in the non-command upland area of East Godavari district. The steady state groundwater flow model simulated to seven observation wells and calibrated for the month of April, 2018. The objective of the model is to assess input and output stresses and to identify the over-stressed areas within the basin. The water budget analysis has revealed that the total groundwater extraction by pumping wells is 83.3% and evapotranspiration loss is 5.7% of the total groundwater recharge in the basin. The groundwater flow following the topography and is towards the mainstream with a maximum velocity of 0.4 m/day. The results revealed that the southern part of the basin is experiencing huge aquifer stress due to over-dependence on deep bore wells. It is recommended that, for at least one season, the most affected dry areas which are under paddy cultivation are to be promoted irrigated dry crops such as maize and jowar. It is also suggested that, due to local high salinity in and around Vannepudi village at the central part of the basin, the horticulture cultivation is to be promoted by increasing the surface water resources. The artificial recharge structures have to be constructed at suitable areas in and around Vannepudi village in order to improve the groundwater quality in terms of high salinity and also to rise the groundwater table in the southern part of the basin.