INVESTIGATION OF SOME POTENTIAL PARAMETERS AND ITS IMPACTS ON SALTWATER INTRUSION IN NILE DELTA AQUIFER.

Coastal aquifers represent an important source of freshwater in arid and semi-arid regions. The increased extraction from coastal aquifers decreases the freshwater spilled out to the sea. Consequently, seawater intrusion increases inland and wells become contaminated. Nile delta aquifer in Egypt is one of these aquifers which subject to sever seawater intrusion from Mediterranean Sea. Saltwater intrusion is considered one of the main processes t hat degrade water- quality by raising salinity. It may occur due to human activities and /or by natural events. Over- pumping is considered the main cause of saltwater intrusion. Moreover, sea level rise accelerates saltwater intrusion. Due to climate change, it is expected a rise in temperature which would lead to an increase in the rates of evaporation and this will be accompanied by decrease in water level of the Nile, also this change would lead to sea level rise (SLR) .A result to rise in population intensity and expected shortage in surface water would lead to an increase of extraction rate from groundwater. In this paper 3-D model (SEAWAT) is used to study sea water intrusion in Nile delta aquifer considering different scenarios, the first scenario is the increase of sea level by 25, 50 and 100 cm, the second is to decrease the surface water system by 25, 50 and 100 cm, the third is to increase the extraction rate by 25, 50 and 100 % and fourth scenario is a combination of while the three scenarios. The results show that saltwater intrusion in East Nile delta reach 76.25 km from shore line for base case, but reaches to 79.25 km, 79 km, 82 km and 83 km for Equiconcentration line 35 and reaches to 92.25 km, 92 km, 91.75 km and 92.75 km for scenarios1, 2, 3 and 4 respectively after 100 year for Equiconcentration line 1.00. It is also observed that salt water intrusion in the Middle reaches to 63.75 km from shore line for base case, but reaches to 67. 75 km, 67.25 km, 65.75 km and 67.50 km for Equiconcentration line 3 5 and reaches to 97 km, 97.50 km, 107.75 km and 110 km for scenarios1, 2, 3 and 4 respectively after 100 year for Equiconcentration line 1.00. It is clear that saltwater intrusion in the West reaches to 48.00 km from shore line for base case, but reaches to 49.00 km, 48.75 km, 45.50 km and 47.7 5 km for Equiconcentration line 35 and reaches to 73.75 km, 74 km, 79.50 km and 79.50 km for scenarios 1, 2, 3 and 4 respectively after 100 year for Equiconcentration line 1.00. Finally increasing SLR or decreasing recharge from [ABSTRACT FROM AUTHOR]