Examining the impact of rangeland condition on water conservation by using an integrated modelling approach

Abstract

Rangelands in the arid and semi-arid regions of Iran are under pressure from frequent degradations and extreme climate conditions, which have affected water conservation and delivery of ecosystem services. The timely and efficient assessment of rangeland state/condition impact on water conservation is crucial in rangeland management. This work represents an integrated modelling approach by linking the Soil and Water Assessment Tool (SWAT) and the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) models. SWAT simulated hydrologic components, while InVEST provided a decision support system for water conservation. The coupled SWAT-InVEST model was used to analyze the impact of different rangeland conditions on water conservation in the Atrak River basin in Iran's arid and semi-arid climatic zones. Increasing runoff is proportional to rangeland degradation. Our analysesshow a severe degradation of rangelands in Iran. We found that the basin's average runoff varies between 2 and 294.8 m 3 ha -1 yr -1 . Based on our modelling results, about 50% of the basin's runoff came from poor rangelands, 22% from moderate rangelands, and 28% from good rangelands. Thus, a significant impact on water conservation could be achieved through rangeland management in this basin. The SWAT-InVEST integrated modelling approach developed here proved useful for better decision-making under uncertainty.

Investigating the Relationship between Precipitation and Vegetation Dynamics with Emphasis on Agricultural Land Cover in the Atrak Basin Area

“…Ultimately, farmers' anticipations regarding future seasonal weather serve as a pivotal factor in guiding cropping decisions [65]. In semi-arid regions like the Atrak basin, where grasslands are prevalent, an annual rainfall range of 300-600 mm (mm) may be considered favorable for maintaining healthy grassland coverage, while, generally, for successful dry agriculture, regions may require annual rainfall ranging from 200 to 500 mm, with variations based on specific crop requirements and local conditions [66]. Sustainable management strategies should prioritize measures to mitigate the impact of droughts, enhance soil moisture retention, and improve the resilience of ecosystems and agricultural systems to climate variability.…”

Land use changes, degradation, and impact on ecosystem services in Asia and Southeast Asia

“…Several studies in the special issue highlight these aspects. For instance, Azimi et al (2021) examine rangeland degradation's impact on water conservation in Iran's Atrak River Basin, revealing a strong link between rangeland condition and water conservation. Shrestha and Acharya (2020) focus on Nepal's Kathmandu Valley, exploring how historical and projected land‐use changes affect ecosystem service values.…”

Factors driving changes in water conservation function from a geospatial perspective: case study of Jilin Province

“…Yang et al (2019) quantitatively assessed water production in the Xiangjiang River Basin and, through sensitivity analysis, showed that precipitation is the most important factor affecting water production. Azimi et al (2020) quantitatively analyzed the impact of runoff on Iranian pastures and determined the impact of different pasture conditions on water conservation functions. Wang et al (2019) quantitatively assessed water production and water conservation in the Shiyang River Basin and analyzed the impact of land use transformation on aquatic ecosystem services.…”