Evaluating and improving the sustainability of ecosystem services in river basins under climate change.

Abstract

This paper presents a new framework for evaluating the sustainability of basin-wide ecosystem services (ESs) including provisioning, regulating, supporting, and cultural services. In this framework, the Soil and Water Assessment Tool (SWAT) and MODSIM models and experts opinions are used to evaluate the ESs. A group COPRAS-based decision-making approach is also used to evaluate the sustainability of ESs for each water resources management (WRM) scenario under climate change (CC). To show the applicability of the proposed framework, it is applied to the Zarrinehrud river basin under three different CC scenarios (i.e., RCP 4.5, 6.0, and 8.5) for two different time horizons (i.e., 2020-2049 and 2020-2098). This basin is the main water supplier of the largest hypersaline lake in the Middle East, Lake Urmia. In the next step, 128 WRM scenarios are taken into account considering the projects defined by Urmia Lake Restoration National Committee (ULRNC). All mentioned services are evaluated considering all WRM and CC scenarios. The results show that WRM scenario 128 is the best scenario for improving ecosystem services in the study area. This scenario includes some projects such as allocating water to the lake from new resources, rehabilitating irrigation and draining networks, and improving cropping patterns.