Impacts of climate change and human activities on vegetation NDVI in China’s Mu Us Sandy Land during 2000–2019

Abstract

There are many ecologically fragile areas similar to China’s Mu Us Sandy Land in the world, which are facing ecological and environmental problems, and improvement of its vegetation cover is essential to those regions’ sustainable development. In this study, spatiotemporal patterns in the Sandy Land’s vegetation cover between 2000 and 2019 were monitored using the Normalized Difference Vegetation Index (NDVI) data (MOD13A1-NDVI). Correlation analyses of regional climate change (precipitation and temperature) and NDVI-related land cover parameters, and quantified respective contribution rates using the residual analysis, indicated that: (i) accounted for 43.5% of the Sandy Land by area, zones of significant improvement in vegetation cover occurred predominantly in the east and southeast. In contrast, the Sandy Land’s central and northwest regions, accounting for 56.5% of their area, showed little change in vegetation coverage. (ii) in terms of overall trends in vegetation improvement, interannual changes in vegetation cover were highly spatially consistent: vegetation coverage was high in the east and south, but low in the central and western regions. (iii) within the Sandy Land, a correlation existed between NDVI and precipitation, and between NDVI and temperature, with the former being the stronger with a positive correlation across 99% of the Sandy Land. (iv) since zones with unchanged land cover contributed 85% of the change in NDVI, changes in the Sandy Land’s NDVI values were not related to changes in land cover types, but rather to the improvement of vegetation within land cover types. (v) the contribution rate of human activities to vegetation improvement was 62.68%, while that of climate change was 37.32%. These results can hopefully provide support for local government in the development of an ecologically sound environment.