Application of Decision Support Tools for Water ResourcesManagement (Case study: Surdud Drainage Basin-Yemen)

Abstract

The main purpose of this study is to identify and priorities suitable measures and strategies for water resources management for Wadi Surdud area. The study area is part of the western drainage basin of Yemen. Wadi Surdud is an arid/semi-arid basin draining of 4050 km2. It is one of the main wadis (intermittent streams) descending from the semi-arid western mountains of Yemen to the red sea. The water resources in the area generally suffer from escalating pressures due to the high consumption of water by agriculture and other water use sectors. Following top down approach Water Evaluation and Planning System (WEAP) model for the study area was used to evaluate water needs and scarcity among all use sectors under a range of potential adaptation strategies. Following the bottom up approach which based on stakeholder consultation a Multi Criteria Analysis Model (MCA-WEAP) is then used as a decision support tool for determining preferences and prioritization among these adaptation strategies. The adapted strategies and measures are, Rehabilitation of traditional irrigation channels, Conveying irrigation water through closed conduits, the use of drip irrigation method and changing crop pattern. In terms of annual water saving the WEAP model showed the most effective strategy is Drip Irrigation Method followedn by conveying irrigation water through Closed Conduits then Rehabilitation of Traditional Irrigation Channels and finally Changing Crop Pattern. On other hand the MCA-WEAP result shows that Changing Crop Pattern from Qat to coffee trees
have high priority than other strategies then improving irrigation efficiency through Using Closed Conduits or Using Drip Irrigation method and finally Rehabilitation of Irrigation Channels. It is learned from this study that, the choice of adaptation strategy is not only based on how much water is saved by each strategy but depends on the influencing socio-economic conditions of a particular study region, including both physical and stakeholder inputs.