Evaluation of basins sustainability by combining the game theories and the composite sustainability indicators in the Beheshtabad inter-basin water transfer plan

In recent decades, urban, industrial and agricultural development has led to growing challenges in water resources supply. The challenge has deepened due to natural hydrological variability, severe droughts, climate change and inadequate water resources management policies. Thus, we are witnessing more and more conflicts among water users over limited water resources. Such conflicts are more intense in inter-basin water transfer projects which are often costly and affect water rights and interests of numerous water users. Due to the complexity of process, it is very important for water policy makers in such projects to rely on a tool for decision making. Sustainable development can be considered as an appropriate approach in this process based on existing needs, without conflicting with the needs of future generations. In this research, an experimental method has been adopted for assessing sustainability in a large-scale and controversial water transfer plan in central Iran, called Behesht-Abad. Sustainable development can be considered from different aspects, one of which can be taken into account as conflict stability and the other as hydrological sustainability. The first one can be evaluated by the concepts of stability definitions in non-cooperative game theories. Non-cooperative game theory involves a stability analysis in order to show which stability definition determine the behavior of the two players as source and recipient basins. If all players achieve a stable solution, they do not move from that condition and the situation remains stable. It is also necessary to evaluate each player's priorities and their choices and solutions in relation to the water transfer project to develop a conflict model. A conflict model called GMCR+ was executed to analyze various solutions and scenarios between the two players. GMCR+ generated a list of all possible states, whereas infeasible states were removed after evaluating the produced scenarios. Then, the most stable scenarios among various solutions are selected in terms of cooperative and non-cooperative scenarios. In the next step, the hydrological sustainability of the selected scenarios must be examined. Sustainability can be quantified by various multidimensional indicators. However, the largest problem is to interpret the combination of all these indicators in such projects. Various methods of aggregating could be applied to achieve composite indicators to help this problem. Development of composite indicators may be beneficial in such large-scale inter-basin water transfer project. Aggregating indicators involves multivariate analysis, data standardization, assignment of weights, and applying different methods of aggregating. In this study, 10 indicators of sustainability in three dimensions of economic, social and environmental were used, which finally turn into four composite indicators to obtain a robust analysis. Then, the hydrological sustainability of the two basins in the selected scenarios based on the composite indicators of sustainability (CIS) was investigated through a simulation model. MODSIM simulation model was adopted to simulate the selected scenarios. Also, a multivariate statistical method such as principal component analysis (PCA) was performed to determine the main indicators in the source and recipient basins. Comparative analysis of the individual CIS was performed to prove whether they are really delivering the same concept of sustainability in inter-basin water transfer. Correlations analysis among the composite indicators showed that they were normally distributed, so Pearson's ratio was utilized as a test of parametric correlation. The results revealed that using various methods to construct composite indicators can help further to analyze the dimensions of such large-scale projects. According to PCA method, all selected indicators were essential for extracting CIS approaches and none of them could be ignored. The results also indicated positive and significant correlations between more CISs. However, it depended on the kind of method used for weighting and aggregating methods. In addition, despite stability of the region, the hydrological sustainability of the two basins did not seem to be appropriate. Although obtaining revenue for source basin seemed fair in point view of the game theory analysis, the hydrological sustainability was reduced in every four applied methods. The recipient basin would not be in a better condition. The results showed, the hydrological sustainability of the recipient basin would not increase significantly due to the use of transferred water in projects development and lack of supply and demand management. Therefore, transferred water for a short time might solve the problem of water shortage in recipient basin, but in the long run, problem would return more seriously.