Genetic Algorithm Model to Optimize Water Resources Allocation in Gaza Strip

Abstract

Groundwater aquifer is considered the main and only water supply source for all kind of human usage in Gaza Strip (domestic, agricultural and industrial). This source is severely deteriorated in both quality and quantity for many reasons, includ- ing low rainfall, dramatic increase in the urban areas and population, pollution from overland activities, and seawater intrusion. In 2011, the Palestinian Water Authority has instituted a plan for integrated management of Gaza water resources that considers introducing of new external water resources to the system such as seawater desalination and treatment and reuse of wastewater. In this work, a genatic algorithm model was developed to seek the optimal combination of the management scenarioios of Pales- tinian water authority plan. The optimization code is designed and run using MATLAB R2011b. The objective function maxim- ized the benefits and minimizes the cost related to the use of different sources of water. The decision variables represents water allocation over different users sectors. The benefits from utilizing water for municipal and industrial purposes are based on the marginal value of water which is derived from the economic equilibrium point between supply and demand curves. The benefits from irrigation water are affected by the relationship between crop yield and salinity. The constraints in the optimiza- tion model are allowed to iterate between two bounds (upper bound and lower bound) until the optimal value for each variable is found. The results show that there is a significant improvement in aquifer’s water levels in the majority area of the Gaza Strip for the planning years 2015, 2025, and 2035 providing that the planned phased desalination and wastewater treatment schemes are implemented in the specifies time horizon. The results show that the resulted quality of available water for agriculture use in term of total weighted average of electrical conductivity is 962 µS/cm in the year 2015, and 876 µS/cm in the year 2025, and 842 µS/cm in the planning year 2035. The results also show that the resulted quality of available water for municipal and industrial use in term of total weighted average of electrical conductivity is 867 µS/cm in the year 2015, and 685 µS/cm in the year 2025, and 631 µS/cm in the planning year 2035.