Application of a Decision Support Tool to Assist Water Governance Within a Water-Stressed Area: Case of the Souss Basin, Morocco

Abstract

The Souss basin in Morocco is distinguished by an uneven surface water supply and steady overexploitation of groundwater resources. In recent years, the basin experienced constant disrupted water balance, due mostly to year-to-year variable weather conditions and rising water demand. This situation is projected to affect the region’s economic development and threaten the prospects of many economic sectors. Therefore, this study was conducted to analyze the water balance of the Souss basin as well as to develop a decision support tool (DSS) to assist water sector managers in sustainable water governance. MODSIM 8.1, a generic river basin management decision support system, for water allocation modeling designed as a computer-aided tool, was selected for that study. Once calibrated and validated over the period from 1990 to 2019 using recorded data about physical processes and hydraulic infrastructures, the model is used to simulate water supply and demand in the Souss basin. The findings indicate that the basin’s water resources are vulnerable, and dams’ inputs in the basin have undergone significant fluctuation under both changing climate and increasing water demand in the growing area. In addition, there is a significant amount of unmet demand across all demand sites. As result, the average total unmet demand for surface water from reservoirs in irrigated areas reached 201 mm³ between 1990 and 2019, and the monthly average demand increased by 55% in the dry season, compared to the demands in the rest of the year. The significant amount of unmet demand across all demand sites suggests that demands are satisfied by the withdrawal of water from groundwater resources. Using MODSIM, the adopted simulation approach has shown to be a useful decision support tool to understand water resources planning challenges. Water managers require reliable tools to represent the basin’s various trade-offs with regards to water resources. Thus, an investigation improving the representation of groundwater/surface water interaction in operations modeling is required to enhance the evaluation of the consequences of different uses at the basin level.

To see the full article : click here.