Groundwater Quality Assessment Using Water Quality Index (WQI) Approach: Gaza Coastal Aquifer Case Study

Abstract

Water resources in arid and semi-arid regions, such as the Gaza Strip (GS), are generally under increasing stresses in terms of water quality and quantity. Therefore management of these valuable resources is one of the crucial concerns and challenges facing researchers and specialists worldwide. In these areas, there is a pressing need to evaluate the water situation in terms of its quality using the available limited data. The Water Quality Index (WQI) helps managers and planners working in the water sector to qualitatively map water quality; which in turn enables them to propose the possible management options, and to prioritize the capital investment for the water sector. Being the only source of water for the GS population of more than 1.8 million, the Gaza Coastal Aquifer (GCA) is in a disastrous quality situation. It represents an extreme prototype model on how several negative factors (unstable political environment, disastrous economic situation, decaying environmental conditions, unplanned & disorganized human activities), are combined together to further deteriorate the groundwater quality. The objective of this paper is to assess and map the spatial distribution of groundwater quality of the GCA using the WQI approach. Research results indicate that severe water quality deterioration has occurred in the GS. The area fraction that is classified as "not good" based on the WQI jumped from about 30% to 55% over 10 years (between 2000 and 2010). The WQI maps developed in this research work assisted in forming a simple yet comprehensive view about groundwater quality in the GS. This, in turn, helps spotting critical locations in terms of water quality, and setting management priorities accordingly. In summary, the space-time analyses of WQI provide support for the decision making process, i.e., for drawing policies and proposing remediation measures to restore and maintain water resources.