Development of the grey approach in water resources management using risk indexes

The aim of this study is to develop COPRAS and Grey COPRAS multi-criteria decision making methods for selection the best alternative for adaptation the effects of climate change in supplying the agricultural sector in Gharranghu basin in East Azerbaijan province. According to the existing hydro-climate conditions, adaptation scenarios in agricultural sectors are selected and based on the results of evaluation and planning water (WEAP), risk indexes in each scenario are calculated based on mathematical equations. In order to prioritize and select the best alternative, adaptation scenarios are considered as alternatives, and risk indexes are regarded as criteria in COPRAS and COPRAS-G multi-criteria decision making methods. Results showed risk indexes will improve by implementing adaptation policies, so that drought risk index would decrease through reduction water consumption from 5% to 25% respectively. Also, the best alternative for adapting the impacts of climate change phenomenon by using COPRAS method was fifth alternative, namely 25% reduction in water demand in agricultural sector, while COPRAS-G method introduced second alternative namely 10% reduction in water demand as preferred alternative. However, it should always be assumed that any prediction of results for the coming years due to complex climatic conditions and the resulting effects of this are associated with uncertainty.