Design and sustainability assessment of water strategy scenarios based on resource carrying capacity and multi-criteria decision-making: the case of Algiers

In semi-arid countries, water scarcity is one of the leading challenges for urban and regional sustainable development. Urban growth trends and increasing competition for limited natural water resources among different uses and localities have prompted governments to resort to intensive desalination. Taking the case of Algiers Province, this paper examines the possibilities of supporting urban growth through a sustainable urban water intervention strategy in the face of drought threats. To this end, it puts forward an original scenario selection method based on targeted water resource carrying capacity (WRCC) and combined multi-criteria decision-making (MCDM) techniques. The research novelty lies in the fact that scenarios are developed by cross-referencing supply and demand scenarios in response to a predefined WRCC. To achieve this, we adopt a scenario approach that focuses on improving the existing water system and adapting it to anticipated growth and drought trends while reducing dependence on conventional water, which is subject to disputes between different uses and localities. Finally, the sustainability assessment of scenarios relies on the use of hybrid MCDM methods, in which Game theory is employed to combine criteria weights. The results indicate that intensive desalination is not a sustainable option and that reducing demand, along with the use of recycled water, can achieve a balance between supply and demand, supporting growth while maintaining efficient management of water resources. The proposed model can help officials and decision-makers plan a sustainable water strategy for drought-prone areas.