Correlation Assessment of NDVI and Land use Dynamics with Water Resources for the Southern Margin of Mu Us Sandy Land, China

Abstract

To prevent desertification, countries all over the world have made diversified efforts and vegetation restoration has been proved to be an effective approach. However, for sandy land that has limited water resources, measures such as artificial vegetation, may lead to the increase risk of drought. While affirming the achievements of sand utilization, there are many controversies exist regarding the advantages of turning deserts green, especially considering the water scarcity. Therefore, the long-run and causal relationships between sandy land, water consumption and vegetation coverage are necessary for explorations. Taken the southern margin of the Mu Us Sandy Land as the study area, this study explored the interactions between sandy land, water consumption and NDVI over a period of 2000–2018 with a VAR model approach. In the study area, various revegetation projects have made great achievements, resulting in a significant reduction of the sandy land area. In addition, the NDVI has ascend from 0.196 in 2000 to 0.371 in 2018 with a ratio of 89.3%. Results showed that there exist long-term stable equilibrium and causal relationships between water consumption with sandy land and NDVI. The increase of NDVI is relatively the direct factor causes the increase of water consumption. It could be inferred that those artificial vegetation measures may be based on large amount of water consumption, which may aggravate further water shortage and ecological damage. More scientific and stronger water resources management measures need to be implemented locally to achieve a balance between water resources and revegetation.