Possible Impacts of Climate Changes on Freshwater in Coastal Aquifers

Mohsen M Sherif, Ahmed Sefelnasr, Abdel Azim Ebraheem, Akbar Javadi

Groundwater resources in coastal aquifers constitute a main source of freshwater in many regions around the globe. This is typically true in arid and semi-arid regions where rainfall is scarce and infrequent and the surface water resources are almost absent. The consequences of climate changes and global warming on the freshwater in coastal aquifers have been investigated by several researchers over the last two decades. Due to the expected increase in the global temperature and the associated expansion of water in oceans and seas, the seawater is expected to rise. This seawater rise would lead to land submergence along the coastline and also an increase in the hydraulic head of seawater at the seaside boundary. Investigations revealed the seriousness of the problem and undesirable possible consequences on land loss and degradation of groundwater quality in coastal areas. In addition, groundwater in would be subjected to extensive pumping which may lead to depletion of aquifers. This paper investigates  the possible impacts of climate change on two coastal aquifers located in arid regions; namely, the Nile Delta Aquifer, in Egypt and the Wadi Ham aquifer in United Arab Emirates. For the case of the Nile Delta aquifers and due to the low altitude and flat nature of the coastal zone, vast areas will be submerged was seawater. A numerical model, FEFLOW was used to simulate the possible impacts of seawater rise under different pumping scenarios. It is concluded that the groundwater in both aquifers will be affected but with significantly different degrees.