Multi-Scale Ecological Restoration Strategies to Enhance Water Conservation in Ruoergai on the Qinghai-Tibet Plateau

The Ruoergai Wetland is the highest and largest plateau peat swamp wetland in the world, providing more than 30% of the water for the upper reaches of the Yellow River. It performs vital regulatory functions in maintaining the quality and stability of the regional ecosystem of the Yellow River Basin. It is of great significance to study the spatial and temporal variability of water conservation services as well as ecological restoration and enhancement strategies at multiple scales. Based on field research, using the InVEST model, this study quantitatively assessed water conservation for a long period at the Ruoergai Wetland, proposing a strategy to improve water conservation capacity. The results showed that both grassland (mainly alpine meadow with Kobresia Willd and Cyperus papyrus) and wetland in the study area exhibited degradation. The proportions of significantly decreased, moderately decreased, slightly decreased areas were 50.64%, 16.81%, 11.64%, respectively. There were also significant changes in water conservation capacity from 2020 to 2023, with strong spatial heterogeneity. Average water conservation per unit area ranged from 52.70 to 211.99 mm/m², with a decreasing trend. However, in the past 10 years, the area of soil erosion decreased by about 4735 km². Although the soil erosion situation has improved to a large extent, there is still increasing soil erosion in some areas. Based on the field investigation, the intrinsic mechanisms of water conservation in alpine wetlands were elaborated, the driving forces behind the changes in water conservation functions were described, and further ecological restoration strategies were proposed from the perspectives of engineering measures, spatial zoning, and industrial structure.