Shaanxi Normal University
The relationship between vegetation cover and hydrology is complex, and there is mutual influence between regional vegetation and water production. The Yellow River basin is both the key area for vegetation restoration and the largest water source in the northern region. It is of great significance to study the spatiotemporal characteristics and relationship of its vegetation cover change and water supply services. Compared with other studies, this paper combines vegetation change and water supply services, and uses water production depth to match the NDVI''s long time series to better study the relationship between them. NDVI can objectively reflect the coverage and change of surface vegetation. InVEST model is often used to evaluate the water production service of a region. Based on NDVI data and InVEST model, this paper analyzed the temporal changes and spatial characteristics of NDVI and water production services in the Yellow River Basin from 2001 to 2020 by using trend analysis and related analysis methods, studied the trend changes and correlation between NDVI and water production services, and combined vegetation cover with water supply services to provide a scientific basis for ecological protection and high-quality development in the Yellow River Basin. The results showed that: (1) The NDVI and water production depth of the Yellow River basin show an increasing trend, with the growth rate of 0.05/10a and 1.83/10a respectively. The NDVI is mainly increased significantly, while the water production depth is mainly not increased significantly. In space, NDVI has increased significantly in most areas in the middle of the basin, and the depth of water production has increased significantly in the east and southwest of the region. (2) NDVI showed a positive correlation with water production depth interannually, with a correlation coefficient of 0.75(P<0.01), and spatially showed a spatial differentiation of positive correlation in northeast and negative correlation in southwest. (3) The increase rate of water production depth was the highest under higher vegetation coverage, and NDVI and water production depth were mainly positively correlated under different vegetation coverage, but with the increase of vegetation coverage, the negative correlation ratio between NDVI and water production depth increased. NDVI and water production services in the Yellow River basin have been increasing in the past 20 years. They are closely related in time and space. NDVI and water production services in the Yellow River basin have shown a growth trend in the past 20 years, and the two are closely related in time and space. Vegetation restoration can promote the enhancement of convective instability and vertical movement in the atmospheric boundary layer by changing the nature of the underlying surface, increase the water vapor content, and produce feedback effects on the regional climate and precipitation, resulting in increased precipitation and improved water production services in the region. However, excessive vegetation coverage will increase canopy interception and transpiration, so as to reduce water production. At present, the impact of vegetation restoration on water production is positive, and moderate vegetation restoration is beneficial to water production services in the Yellow River basin.