Water management strategies towards sustainable agricultural development, taking Managed Aquifer Recharge (MAR) and brackish water utilization into Account: Case Study: Auja, LJV, Palestine.

Abstract

Increasing water irrigation demand combined with water scarcity and deterioration of the water quality in the Lower Jordan Valley (hereafter referred to as LJV) - Palestine, has led to a serious challenge in managing current and future water demands. This problem is not restricted to Palestine but to the region in general. Providing feasible solution strategies for water management has demonstrated to be a complex task. Mismanagement of water resources aggravates the problem. Therefore, integrated water resources management promises applicable and creative solutions for the future in terms of water strategies. The main goals of this study are to develop these strategies end based on regional agricultural strategies development. The Case Study Area (Hereafter referred to as CSA), Auja area, is located in the LJV., CSA has suffered from water scarcity and water quality deterioration, This was manifested in decreasing irrigated lands from 10,000 donums in 2010 to only about 4,000 donums in 2013and change in crop patterns in the area. Moreover high chloride concentration in shallow aquifer - with 2000μs/cm² in some wells - has caused increased deterioration in water quality. Therefore, the study investigated creative alternatives based on integrated available water resources management and the exploration of non-conventional resources in the area. The study assumed many strategies of agricultural and water resources development, which jointly constitute strategies of firstly, agriculture development and secondly, water strategies. Both strategies should act as the core of the problem as well as its solution. Accordingly, integrated water resources management (hereafter referred to as IWRM) focused on managing aquifer recharge (MAR) and using brackish water in irrigation. This idea is the base for the assumption of this research. MAR and brackish water eventually are top priority scenarios for meeting water requirements in the future. Decision-makers are urged to take these scenarios into consideration to achieve sustainable development plans in the Palestinian territories. Irrigated lands in the CSA cover 3,800 donums vis-à-vis 30,000 irrigable donums. Main water resources come from Auja Springs and shallow aquifer wells. Available irrigation water does not exceed 3.5 Mm3/a. CSA is served by field survey including soil, water, land, and agriculture cover use. CSA is composed of three Agricultural land zones: zone 1, zone 2 and zone 3. These zones reflect the current cultivated area as well as lands expansion scenarios for an additional 8,500 donums of new irrigated lands with plantations of date palm trees, intensive green house agriculture and grapes. The scenario is based on soil profile analysis of root zone and soil hydrochemistry analysis. Water Management Strategies towards Sustainable Agricultural Development XVI These three land zones represent three agricultural development strategies based on water budget analysis and are jointly linked with the three assumed water strategies. The three water strategies (WSs) are: 1- WS I which is the Do-Nothing approach which reflects large water quantities deficit; 2-The WS II is based on MAR scenario, the Mathematical model of transient GMS-Modflow It is considered as a tool for water management in the CSA. It supplies 2 million cubic meters of surplus water by direct injection into the shallow aquifer wells, in addition to infiltrated flood surface run-off from Wadi Auja. 3-The WS III, is based on 100% of IWRM using all non-conventional water resources, varying from brackish water desalination and treated effluent to importing water from outside the CSA and the use of Current Untapped Water Resources (CUWR). This strategy will change the current crop pattern taking into consideration the water budget. It could offer additional 12 million cubic meters (Mm3) for the extra irrigated expanded land scenario. Evaluating the best management scenarios regarding performance and impact assets based on Driving-Pressure-State-Impact-Response (DPSIR) frame work, would give several decision variables (DVs) as a prelude to form decision criteria analysis and analytical hierarchy procedure (AHP) used for scaling and weighing different decision variables (DVs) This would produce the best management scenario by mixing brackish and fresh water and completely change the crop pattern in the CSA. The change would accrue through planting date palms. In this context, MAR scenario comes as intermediate priority by evaluation results, although it would need further investigation in the future.