Assessment of Human Impact on Quaternary Aquifers of Rafah Area, NE Sinai, Egypt

Abstract

Groundwater is endangered by agricultural activities, wastes disposal, aquifer over exploitation and seawater intrusion. The pollution risk is high, as the depth to the water table is shallow and the aquifers are highly permeable and have poor buffering capacity. Intensive farming activities have also put stress on groundwater quality due to intensive use of fertilizers and pesticides. As a result, concentrations of NO3-, SO42- and PO4-2 are very high. Most of the house owners do not have access to public sewers, which poses another risk for the aquifers. More than 71.2% of the aerial distribution of nitrate concentration is greater than 44.29 mg/L, thus causing a serious problem. Static water level maps from 1983 to 2000 show the declining of the water level with time. The discharge from Quaternary aquifers exceeds the recharge rates after 1988 resulting in both upward leakage of the deeper high saline water and seawater intrusion. Factor analyses were used to define the factors that affect the groundwater quality. Dissolution and deposition of several minerals, evaporation from the groundwater, human impact on the aquifers, cation exchange, mixing between different waters and rainfall recharge were identified as the main factors impacting the ground waters