Sub-watershed Prioritization Based on Watershed Hydrological Security Using Different Multi-Criteria Decision-Making Methods

The state of a watershed is determined by its hydrological conditions, which themselves are dependent on the security of the individual components of the watershed such as economic, social, ecological and infrastructure. While the role of stakeholders in watershed management is vital and their opinions are very effective in management and the assessment of watershed hydrological security (WHS). Therefore, this research aims to evaluate WHS from economic and social perspectives based on stakeholder opinions surrounding the Gorganroud watershed in Iran. The multi-criteria decision-making (MCDM) models including VlseKriterijumska Optimizcija I Kaompromisno Resenje (VIKOR), Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), Simple Additive Weighting (SAW), Complex Proportional Assessment (COPRAS), and Elimination and Choice in Translating to Reality (ELECTRE) were used to prioritize the sub-watersheds according to eight economic, social, and infrastructural variables. Shannon's entropy was used to compute the weight of these variables in the MCDM models. To validate the models, the percentage of variation (∆P) and intensity of variation (∆I) were used. The results showed that the application of indigenous knowledge in water management had the highest entropy with a weight of 0.327 (33%). The water-dependent livelihoods variable had the lowest entropy and weight but was still considered a key variable in WHS due to its consistently high scores among stakeholders. When ranking the sub-watersheds in terms of WHS, the sub-watersheds A9 and A3 were ranked first and last, respectively, for all five MCDM models, with the rankings of the other sub-watersheds differing between the models. A comparison of the evaluation indices showed that COPRAS (∆P = 38.75) and ELECTRE (∆I = 4.805) were the best-performing MCDM models for the WHS ranking of the Gorganroud watershed. The strategy proposed by the present study can facilitate the effective management of the Gorganroud watershed and ensure its sustainable development, and also provide the possibility of effective application of this strategy in another watersheds. Graphical Abstract