Groundwater modelling for recharge estimation towards sustainable management: A case study of the Killinochi, Northern Sri Lanka

Abstract

Continual replenishment of groundwater storage and its sustainable utilisation is indispensable to meet the ever-increasing needs of Killinochi district. To ascertain the sustainable exploitation of groundwater, the area was modelled for initial period of one year followed by a three-year simulation. Literature reviews and prior groundwater investigations show a huge gap in soil and aquifer hydraulic parameters, water-level information, and related aquifer and confining bed geometry data. Therefore, it was not possible to calibrate the model following standard techniques. However, efforts were made to make sure the model represents actual field conditions by incorporating available data. In addition, a comparison of the simulated zonal water budgets with the zonal budgets calculated based on observed data were used to validate the results. The recharge pattern follows a close resemblance with the rainfall pattern, which can be explained by the more or less flat topography. The topography limited any significant contribution of lateral inflows.