Effects of Climate Change on Groundwater Resources (Northern Gaza Strip Case Study)

Abstract

Gaza Strip water sector management is essential for sustenance of life. The knowledge of the occurrence, replenishment and recovery of groundwater assumes special significance in quantity-deteriorated regions, as Gaza Strip because of scarce presence of surface water. In addition, unfavorable climatic condition on one hand and an unsuitable geological set up on the other, a definite limit on the effectiveness of surface and subsurface reservoirs. Thus, a research is essential to confirm the relationship between groundwater in Gaza Strip region and the sustainability of such climate conditions. Given the role of natural resources within the current conflict dynamics, climate change has a significant role to play in groundwater management within the region in next years. Studying the relation between climate change and groundwater resources was carried by estimating the recharge quantities that infiltrate to the aquifer using WetSpass software, then studying its effects on groundwater depth using Modflow software. Finally forecasting the possible scenarios may occur in the future and its effects on groundwater resources were studied. The research showed a minor decrease in temperature and decreasing trend of the rainfall after 1995 which implied the climate change, and consequently influenced the recharge values. The temporal relation between the most sensitivity parameter (rainfall) and the recharge was studied in three presented locations in Gaza Strip: Beit lahia,GazaCityand Rafah rainfall stations with high correlation between the rainfall and recharge trends ranges between 0.96 to 0.99. It's noticed that after year 1995 rainfall decreased by 63.8% in Beit lahia station that caused deficit in recharge values with 87.64%, and lastly decrease in groundwater storage. Then, recharge values were input to calibrated transient groundwater model (Modflow software) for the northern part of Gaza Strip. Two scenarios were considered; the recharge of year 2010 was assumed to still remain and recharge rate decreases at the same trend. Output showed a large decreasing in the water table from -3m at the start date to -6, -7.5, -8 and -8.5m at the middle and from 2m to -3.31, -6, -7 and -7.5m for years 2015, 2020, 2025 and 2030 respectively with clear expansion in the deficit region over time. The same trend observed for the second scenario with larger values. Therefore, it is recommended that all water resources management plans in Gaza Strip should consider the impact of climate change.