Modeling the impact of drought on the Gaza coastal aquifer and potential use of the unconventional water resources

In the region of Eastern Mediterranean, the area of the Gaza Strip is a vulnerable area to the consequences of climate changes where the stochastic model of (4,0,1) (5,1,1)12 might signify that the region of the Gaza Strip risks drought status with an incidence likelihood varying from 8% in the north to 100% in the south. The climate stochastic models reveal that the Gaza Strip region will face a decline in the precipitation by -5.2% and an increase in the temperature by +1˚C in the timeframe of 2020-2040. The potential evaporation and the sunshine period will 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 Gaza Coastal Aquifer is the only water resource that is under stress due to climate change and anthropogenic activities. Hence, the modeling of groundwater table level using the ANN model of 20 neurons indicates that the water table shows a substantial drop below the mean sea level (MSL) by a range between -0.38 m in the northern parts and about -18.5 m in the southern parts of the Gaza Strip. However, the simulation projections reveal that the decline in the groundwater level would decrease sharply by the year 2040 to -1.13 m and -27.77 m below MSL at the northern and southern governorates of the Gaza Strip, respectively. The non-conventional water resources of seawater desalination, wastewater treatment, and stormwater harvesting are promising water resources to enhance the water supply and to cope with groundwater depletion. In total, the current daily operation of the short-term low-volume (STLV) seawater desalination plants produces 36,000 m3 and on the large-scale perspective, the seawater desalination capacity is planned to lift from 150,000 m3 to 300,000 m3 per day by the years 2025 and 2035, respectively. The wastewater treatment and reuse activities are processed through three wastewater treatment plants with a total daily capacity of 130,000 m3 which is proposed to be lifted to a capacity of 235,000 m3 by the beginning of 2025. The simulation outputs of using unconventional water resources to maintain the groundwater integrity indicate that the restoration of the groundwater balance is assigned to +10 m by the end of 2040.