Coupled flow and salinity transport modelling and assessment of groundwater availability in the Jaffna Peninsula, Sri Lanka

The development of a groundwater management strategy is essential for the sustainable management of groundwater resources. This study describes the hydrogeology of the two main geological formations, which contain freshwater resources in the Jaffna Peninsula, Sri Lanka. A numerical groundwater flow model was developed as part of the investigation to assist in the analysis of freshwater and saltwater flow for current and changing pumping and recharge conditions. The groundwater flow model MODFLOW, mass transport model MT3DMS, and salinity intrusion model SEAWAT were used to provide additional understanding of the regional flow conditions in the aquifers, including regional movement of the interface separating the freshwater and saltwater flow systems. The calibrated model was used to estimate water balance for the Jaffna Peninsula, assess the potential for seawater intrusion and upcoming, and its impact on low salinity groundwater resources.