Journal of Hydrology: Regional Studies (Feb 2025)
Evaluation of optimal dam release to achieve agricultural economic-ecological development from stakeholders' perspectives in the Karkheh basin, Iran
Abstract
Study region: The Karkheh Dam and its sub-basin are located in Khuzestan Province, Iran. The Karkheh Dam has a storage capacity of 7.5 × 10^9 cubic meters and is the largest dam in Iran by volume. Study focus: The increasing demand for agricultural and ecological water, along with fluctuations in dam inflows and volumes, has created significant challenges for the economic-ecological management of dam water resources. Stakeholders' perspectives on ecological protection can also fundamentally alter this management. This study aims to enhance agricultural economic-ecological development through a novel approach that combines CART decision tree and multi-objective optimization models, focusing on maximizing farmers' gross margin and water savings from lenient, moderate, and strict perspectives on ecological protection. New hydrological insights for the region: The CART model, with an R² of over 0.92, accurately predicted the Karkheh dam outflows and identified seven different release scenarios based on reservoir volumes and inflows. Water and land optimal allocation of the Karkheh sub-basin indicated that under unfavorable release conditions, farmers would face increased economic pressure, complicating water-saving policy implementation. Under strict ecological protection perspective, the difference between economic and ecological benefits for outflow scenarios S1 (approximately 754 million m3) and S7 (approximately 3906 million m3) was significant, at about 53 % and 10 %, respectively. Therefore, implementing stringent water-saving policies in the Karkheh sub-basin level is feasible under favorable dam water resource conditions. The study concluded that Karkheh Dam release levels have a greater impact on land use than stakeholders' ecological protection perspectives. Based on the results obtained, it is recommended that achieving sustainability in the agricultural sector of dam sub-basins is possible through dynamic and flexible reservoir dam management, considering the perspectives of stakeholders in each region.
