Evaluating the reliability, resilience, and vulnerability of water resources: the impact of minimum, maximum, environmental flows, and water quality

Surface water resources in the Gorganroud watershed are facing significant reliability challenges due to human activities and climate change. This research aims to assess the resilience, reliability, and vulnerability of water resources across 16 sub-watersheds, focusing on minimum, maximum and environmental flows as well as water quality. The findings indicate that the health of the minimum flow over periods of 7, 30, and 90 days is rated at 0.16, 0.32, and 0.45, respectively, reflecting unhealthy to moderate conditions at the watershed level. Additionally, the maximum flow health score of 0.34 highlights the necessity for effective flood management. Water quality assessments for drinking and agricultural purposes were estimated at 0.52 and 0.57, respectively; however, downstream agricultural sub-watersheds with intensive activities, such as Hajighoshan, Dasht, Gonbad, Ghazaghli, and Gorgan Dam, are facing critical conditions. The overall health of the environmental flow in the watershed is rated at 0.47, with the middle and lower sub-watersheds, including Dasht and Gorgan Dam, exhibiting poor conditions, while mountainous areas, such as Till Abad, demonstrate better performance. These results underscore the urgent need for integrated water resource management, vegetation restoration, and the control of agricultural pollution to enhance watershed health.