Applying Climate Adaptation Strategies for Improvement of Management Indexes of a River-Reservoir Irrigation System†

Among the various water users, the agricultural sector is the largest consumer of water in the world. Thus, the implementation of agricultural adaptation strategies is essential for an optimal allocation of water resources in a changing climate. The objective of this study is to examine the changes in management criteria for a multi-purpose reservoir system and its downstream Gharanghu irrigation network in Iran under climate change. Five management scenarios were evaluated by changing cropping patterns. First, simulations were performed by using HadCM3 (under the A2) for different climatic scenarios to quantify future reservoir inflows and estimate the future downstream demand (2040-2069). The results showed that water resources decreased by 20% and water use increased by 25% compared to the baseline (1971-2000). Then, eight management indexes were calculated based on the water resources and uses simulated by the WEAP model for the future. The indexes were compared for conditions with and without applying the climate adaptation strategies. Results showed that flexibility increased by 19% and vulnerability decreased by 1.7% with demand management and a 5% reduction of water consumption, while flexibility increased by 38% and vulnerability decreased by 28% with a 20% reduction of demand. Applying adaptation strategies in agriculture can significantly reduce the negative effects of climate change. (c) 2019 John Wiley & Sons, Ltd.