Statistical modeling of spatial and temporal vulnerability of groundwater level in the Gaza Strip (Palestine)

Abstract

The water supply in the Gaza Strip substantially depends on the groundwater resource of the Gaza coastal aquifer. The climate changes and the over-exploiting processes negatively impact the recovery of the groundwater balance. The climate variability is characterized by the decline in the precipitation by -5.2% and an increase in the temperature by +1 degrees C in the timeframe of 2020-2040. The potential evaporation and the sunshine period are expected to increase by about 111 mm and 5 hours, respectively, during the next 20 years. However, the atmosphere is predicted to be drier where the relative humidity will fall by a trend of -8% in 20 years. The groundwater abstraction is predicted to increase by 55% by 2040. The response of the groundwater level to climate change and groundwater pumping was evaluated using a model of a 20-neuron ANN with a performance of the correlation coefficient (r)=0.95-0.99 and the root mean square error (RMSE)=0.09-0.21. Nowadays, the model reveals that the groundwater level ranges between -0.38 and -18.5 m and by 2040 it is expected to reach -1.13 and -28 m below MSL at the northern and southern governorates of the Gaza Strip, respectively.