Recreating of Watershed Sustainability Index (WSI) Based on Driving Force-Pressure-State-Impact-Response Framework in the Beheshtabad Watershed

Introduction and Goal 
Healthy watersheds provide many ecosystem services in various fields such as social and economic welfare. Therefore, the comprehensive assessment of watersheds is one of the undeniable necessities of watershed resource management. Awareness of the health and sustainability of watersheds are fundamental components of sustainable watershed management. Achieving this awareness requires a completely systematic and holistic approach. Various methods and models have been proposed by researchers in the fields of environmental science and ecology to evaluate the health of different ecosystems. Environmental agencies have developed models to examine changes in the environment through the lens of human-environment interactions, with the simplest being the pressure-state-response model. For a watershed, it is essential to define and determine indicators that can assess the health or sustainability of the watershed, or to rank the condition of a watershed using mathematical methods and relationships. This research aims to present a multidimensional indicator concerning watershed sustainability that can encompass as many aspects of health and sustainability as possible.
Material and Methods
To accomplish the objectives of this research, the Watershed Sustainability Index (WSI) has been developed through the selection of criteria categorized into four dimensions: hydrology (both quantity and quality), environment, life, and policy (HELP). The Driving Force-Pressure-State-Impact-Response (DPSIR) framework serves as a versatile and supportive system approach that aids decision-makers across various phases of decision-making. In this study, to identify the most appropriate and representative sub-criteria from a range of options, comprehensive reviews of existing scientific literature and consultations with experts were conducted. Each sub-criterion was assessed across four sub-basins of the Beheshtabad watershed in Chaharmahal-va-Bakhtiari province, with normalized scores ranging from 0 to 1 assigned to each.The overall score for the watershed sustainability index was derived by applying equal weights to each criterion through the arithmetic mean method.
Results and Discussion
The findings indicate that the overall WSI status of the Beheshtabad Watershed is rated as average (0.625), with minimal variations among the sub-watersheds. The watershed sustainability index for the sub-watersheds of Borujen, Farsan, Kiar and Shahrekord is recorded at 0.65, 0.61, 0.65, and 0.67, respectively. The environmental criterion across the four sub-watersheds of Beheshtabad has achieved superior score. The policy score remains consistent across all four sub-watersheds, as the criteria are evaluated at the national level. Also, the Life criteria have garnered similar scores due to the assessment of sub-criteria measured at the broader levels of the sub-watershed. Among the evaluated criteria, the Environment criterion received the highest score, while the Life and Hydrology criteria recorded the lowest. Within DPSIR parameters, the criteria associated with the Impact received higher scores, whereas those related to Pressure received lower scores.
Conclusion and Suggestions
The watershed sustainability index of the Beheshtabad can be enhanced by focusing on the hydrology sub-criterion, fostering greater community involvement in watershed improvement efforts, educating local populations on water conservation practices, and amplifying the participation of local communities in forestry initiatives. Furthermore, environmental quality can be bolstered through increased planting and curbing the pace of urbanization within the watershed. Given the low scores in the Life and Policy criteria alongside a high rating in the Environment criterion, it can be inferred that the geographical determinism affecting the Beheshtabad watershed has contributed to an elevated Watershed Sustainability Index (WSI), indicating that the existing plans and policies are inadequate. This index serves as a valuable tool for watershed managers in their decision-making processes. It allows for the identification of bottlenecks and constraints. Recognizing these limitations presents an opportunity to enhance the current conditions of the watershed, necessitating effective collaboration among various institutions. The WSI is a comprehensive index with significant potential for managing environmental, social, and economic aspects. Based on the results of this research, it is proposed that regular application of this tool, (such as every five years), can furnish managers and decision-makers with a clear understanding of the watershed's sustainability trajectory.