Identifying water sector priorities for adaptation to climate change in the Zayandeh-roud basin with the passive defense approach

The aim of this study was to investigate the main options for adaptation to climate change in the Zayandeh-Roud Basin based on the passive defense approach. Therefore, in the first stage, the temperature and precipitation changes in the basin during future 20-years (2021-2040) were estimated using the weighted combination of the GCM models of the fifth IPCC assessment report. In the next stage, using the comments of various experts and researchers on water resources management and passive defense, the main criteria and options were identified for adaptation to climate change in the Zayandeh-Roud Basin. Based on the scores provided by the experts, pairwise comparisons were performed based on Analytical Hierarchy Process (AHP). The results showed that on average, the temperature of basin will increase by about 0.9 °C during the next 20-years and the precipitation of the basin will decrease by about 13.3%. Among the criteria selected for adaptation to climate change based on the passive defense approach, the criterion of "no damage to farmers' livelihood" had the highest score. Also, among the options for adapting to climate change, "water demand management", "increase water supply" and "reduce water supply" received the highest scores for adapt the basin to climate change, respectively. In general, the results showed that supply-side water policies as well as water rationing policies can not be good policies for reduce risks and conflicts in water management, and if water demand management policies are implemented properly, future threats to water resources management (with a passive defense approach), can be reduced.