Drought Risk Analysis in Agricultural Water Delivery System, A Case Study of Roodasht Irrigation Districts

The occurrence of continuous water shortage as a natural hazard has dramatically impacted the country's performance of surface water delivery systems. In this research, drought risk analysis in surface water delivery systems in Roodasht irrigation network has been investigated. For this purpose, the streamflow Drought Index (SDI) has been used to assess the region's probability of drought. The consequence of drought was calculated by combining water distribution performance evaluation indicators, efficiency, adequacy, and justice with a simple additive weighting method (SAW) in five weight scenarios based on different management perspectives. Finally, by combining the probability and consequence of drought, the risk of this phenomenon in the agricultural water distribution system was calculated and analyzed. According to the SDI index, the results showed drought occurred in the monthly period with magnitude of -2.42 to 2.47, and in the annual period with magnitude of -2.54 to 1.65. The range of monthly drought risk values of the system in five weighted scenarios is as follows: evaluation perspective with emphasis on the opinion of the network administrator (0.668 to 0.804), With the emphasis on the beneficiary's opinion (0.636 to 0.803), the simultaneous emphasis of manager and beneficiary (0.647 to 0.802), emphasis on regional water opinion and provincial managers (0.684 to 0.804), and with emphasis on environmental considerations within the irrigation network (0.692 to 0.804). The obtained results of employing the risk analysis framework in both annual and monthly periods make the authorities present appropriate alternatives considering the magnitude and timing of the system's failure risk.