A novel framework for evaluating water resources and environmental carrying capacity under climate change: The Zarrinehrud Basin experience

This paper presents a novel approach for quantifying and assessing water resources and environmental carrying capacity (WRECC) leveraging the Drivers-Pressures-State-Impacts-Responses (DPSIR) framework. Unlike previous approaches that were based on aggregating all DPSIR indicators to quantify WRECC, our framework explicitly integrates influence pathways into WRECC estimation through the “Impacts” component, capturing long-term systemic effects of upstream changes (e.g., drivers and pressures) on sustainability outcomes. Targeted strategies are designed to enhance WRECC under climate change scenarios (representative concentration pathway (RCP) 4.5, 6.0, and 8.5) by directly and/or indirectly modifying DPSIR criteria, with impacts evaluated across environmental, socio-economic, and cultural dimensions. The superior strategy is selected using the fallback bargaining method incorporating stakeholder utilities to ensure feasibility and acceptance. Applied to Iran's Zarrinehrud Basin, located within the Lake Urmia basin, the world's second largest saltwater lake, the framework reveals baseline conditions' WRECC as severely overloaded due to agricultural expansion and climate pressures. Simulations of 40 strategies for the periods 2000–2023 and 2024–2039, using climate change scenarios (i.e., RCP 4.5, RCP 6.0, and RCP 8.5) demonstrate that conventional measures (e.g., irrigation efficiency) alone fail to restore balance. In contrast, Strategy S39, reducing agricultural employment by 30 % while promoting industry and tourism, improves WRECC by 53 %, achieving a balanced state by 2039. Key findings highlight that strategies targeting “drivers” (e.g., employment shifts) outperform those focused solely on “pressures” or “state” components, underscoring the need for systemic interventions. The proposed framework's adaptability offers a transferable tool for basins facing similar sustainability challenges.