Adaptation strategies and future concerns for ecological restoration of Lake Urmia Basin, Iran

The desiccation of Lake Urmia, Iran, represents a critical environmental crisis driven by water scarcity. In 2010, the "Integrated Management Plan for Lake Urmia Basin" was implemented to restore the lake, primarily by improving agricultural irrigation efficiency from 35% to 60% to reduce water withdrawals by 40%. This study evaluates the hydrological outcomes of this restoration plan between 2010 and 2022, specifically investigating the interplay between policy-driven efficiency gains and concurrent land use changes. We employed a spatial land use model to analyze changes in agricultural patterns. Our findings indicate a significant divergence from the plan’s assumptions. While irrigation efficiency improved, the area of water-intensive orchards expanded by 68.4%, 15.5% more than the 52.9% increase anticipated by the plan. This unplanned agricultural expansion increased regional water demand, offsetting the water savings from efficiency improvements. Consequently, the strategy did not lead to a net increase in inflows to the lake. Furthermore, a rising trend in maximum land surface temperature was observed, indicating an increasingly challenging climate context. The results demonstrate that the restoration strategy was unable to improve the lake’s water balance. The lake of integrated water and land governance allowed for efficiency gains to be effectively canceled out by shifts to more water-intensive cultivation. This study highlights that technological interventions for water savings are insufficient without robust governance mechanisms that manage overall water consumption. Our findings provide critical insights for designing more effective ecosystem restoration policies in water-scare regions globally. • The effectiveness of the adaptation strategy on Lake Urmia's sustainability as one of the important hot spots was assessed. • Land use changes under adaptation strategy and trade-off were simulated. • Orchard's contribution to hydrology across the lake basin was simulated over 2020–2022. • We showed how farming intensification drives water availability and region’s sustainability.