Ecological-Economic Assessment and Managerial Significance of Water Conservation in the Headwaters of the Yellow River

The water conservation function plays a vital role in the land-water cycle. As the "Chinese water tower", the headwaters of the Yellow River are of great significance to the safety of the Yellow River basin and even the global ecosystem. Taking the grassland ecosystem in the Yellow River source area as the research object, the InVEST water yield model with modified parameters and the ecological value evaluation of the modified equivalent factor method were used to explore the simulated spatio-temporal changes and the value of grassland water conservation from 2001 to 2020. The results show that: (1) the average total amount of water conservation in the source area is 549 x 10(8) m(3), which is 16% of the runoff in the Yellow River basin, with a growth rate of 7.5 mm/year 1 and a contribution rate of 30%; (2) the total ecological value of grassland water conservation in 2020 is USD 340.03 x 10(8). The proportion of improved grassland in ecological restoration and management is only 0.51%, while the proportion of original alpine meadow reaches 67% and its ecological function and value are irreplaceable; (3) based on the comprehensive indicators of water conservation capacity, value and importance, Qumalai, Chengduo and Maduo counties are ranked as priority areas for the ecological protection of water resources.