Effects of Sea Level Rise and Recharge Rate Variations on Seawater Intrusion in Confined Aquifer

Approximately, 60 percent of the world's populations are living at a distance of 60 kilometers from the coasts. In coastal zones, coastal aquifers are the most important resources of the available freshwater. It is believed that short-term or long-term impacts of the climate changes affect such aquifers. In general, it is predicted that climate changes e.g. sea-level rise (SLR) cause an increase in seawater intrusion (SWI) in the coastal aquifers. A confined coastal aquifer is considered in this study. The main objective is to investigate sea water intrusion phenomena occurring in the coastal aquifers due to climatic change impacts and aquifer parameters. For 2D simulation of groundwater system and SWI determination, a numerical model, SUTRA is used. The impact of SLR based on IPCC (2013) predictions are assessed under both steady-state and transient conditions. The results obtained for a confined coastal aquifer show that SLR effect on salt wedge is negligible under steady-state condition. Under transient condition, a self-reversal mechanism is observed due to groundwater system response to SLR. At the early time, SWI reached the maximum value, and then with time gradually returns to its initial state. The results of this study can be applied to real cases of coastal aquifers. Such aquifer-behavior analyses can be really helpful and useful for further explorations.