11. Assessment and Management of Seawater Intrusion in Gaza Aquifer Due to Over Pumping and Sea Level Rise

Climate change, rising sea levels, over pumping and seawater intrusion (SWI) pose major challenges to water resource management in coastal areas. Over pumping is considered a major cause of SWI into coastal aquifers and rising sea levels accelerate the intrusion. The combined effects of over pumping and rising sea levels make the problem worse and require more attention. Therefore, SWI due to over pumping and rising sea levels should be predicted and controlled to protect groundwater. In this study a coupled transient density-dependent finite element model is developed to investigate the effects of over pumping and rising sea levels on SWI in Gaza aquifer. Three scenarios are considered: over pumping, rising sea levels due to climate change and combination of the two. The results show that rising sea level has a significant effect on the intrusion of saline water. However, the combination of sea level rise and over pumping results in more intrusion and large amounts of freshwater in the Gaza aquifer could be polluted. To manage SWI into Gaza aquifer, three scenarios have been presented including decreasing abstraction from the aquifer and using other sources of water such as desalination, increasing recharge to the aquifer using tertiary treated wastewater and combination of the two. The results revealed that using tertiary treated wastewater to increase the recharge to Gaza aquifer combined with decreasing the abstraction from the aquifer could help in protecting the aquifer from deterioration.