Evaluating the Carrying Capacity of Water Resources inRiver Basin Scales

In recent decades, overexploitation of water resources as a result of increase in water demands, waterresources pollution, and increasing drought and flood events resulted from the climate change havesignificantly degraded the water resources. Evaluating the carrying capacity of water resources can helpensure the healthy state of water, environment and ecosystems, and guarantee the sustainable developmentof societies. In this paper, we use a pressure-support-state-based framework to evaluate the carryingcapacity of water resources under extreme drought events and define new criteria to quantify the involvedindices by addressing both natural processes and human interventions. A coupled SWAT-MODSIM modelis used to simulate extreme events. The proposed framework is applied for estimating the annual carryingcapacity of water resources in a real-world case study. The results indicate that the historical (۱۹۹۱-۲۰۱۲)and current status of the carrying capacity of the Zarrinehrud river basin is not favorable and thecontinuation of the current trend (scenario S۱) will exacerbate the status of the water resources in terms ofcarrying capacity. However, implementing scenario S۲, which reduces agricultural water consumption by۴۰% and as a result, increases the inflow to the Urmia Lake, can enhance the carrying capacity of the waterresources up to ۳۲%.

Keywords:

Water resources carrying capacity , Zarrinehrud river basin , Pressure-support-state , Extreme Drought events , SWAT-MODSIM