Development of a Combined Index to Evaluate Sustainability of Water Resources Systems

It is necessary to assess water resources sustainability for development and management of a large-scale water resources system with various components such as reservoirs, inter-basin water transfer, and consumers and stakeholders in various sectors including drinking, industry, fish farming, agriculture, and environment. For this purpose, in the present study, a spatially-distributed model was developed based on the system dynamics approach. Then, a set of individual indexes were utilized to evaluate the behavior of a water resources system by considering quantitative/qualitative environmental, economic, and water productivity aspects. Each of the individual indexes was computed for all system nodes. A combined index was further developed and applied to evaluate the system sustainability. To evaluate the efficiency of the combined index and ensure its proper performance, the new method was compared with the well-known multi-criteria decision making method. The results indicated that the combined index was 15.315 for sustainable development with implementation of an integrated water management policy, while the index for the current condition was 15.361. For other management policies that were not based on the integrated management concept, the values of the combined index were higher than those for the current condition.