Evaluation of the Impact of the Ongoing Water Resource Management Plans on Nitrate Concentration in Gaza Coastal Aquifer Using Modeling Approach

Abstract

Groundwater crisis in Gaza includes two major folds: shortage of water supply and contamination. The groundwater pollution by nitrates increased rapidly as a result of wastewater leakage, sewage sludge, animal manure and N-fertilizers. The aims of this study are to obtain the impacts of implementing the Gaza Emergency Technical Assistance Programme (GETAP) on the nitrate concentration in groundwater in Gaza Strip using modeling approach. A flow and transport model using a three dimensional, finite difference simulation model (VMODFLOW Pro.) was applied to simulate the Gaza coastal aquifer (GCA). The approach for selecting the management scenarios was carried out depending on the GETAP projects and focuses into the aquifer system during the next 24 years. It was estimated that work as usual scenario will raise the average nitrate concentration by 8.15 mg/l annually, while upgrade and maintain pipe work scenario will reduce the rising of average nitrate concentration by 4.51 mg/l annually. This means that the average nitrate concentration will increase by only 3.63 mg/l annually. Also, it was estimated that scenarios imported water from Israel, construction of short term low volume desalination plant (STLV), Construction of two regional desalination plant and Reuse of treated wastewater in addition to decrease N-fertilizer will annually increase the average nitrate concentration by only (4.67, 2.78, 3.87, 2.15) mg/l, respectively. The results show that applying all the scenarios together will decrease the average nitrate concentration by 2.44 mg/l annually. Regionally, the best scenario to solve the increasing of nitrate concentration problem is a combination of those scenarios. In domestic areas, the best scenarios is STLV and upgrading and maintaining pipe work. In Agriculture areas, the best scenario and the only one that has significant effect is the reuse of treated wastewater in addition to decrease N-fertilizer.