Spatiotemporal Variation of Vegetation on the Loess Plateau and the Potential Influencing Factors on Vegetation Trend

In this study, the spatial–temporal evolution of the vegetation NDVI during 1999–2019 was analyzed,and the driving forces(including factors of climate and human activities) of the evolution were identified using the partial correlation coefficient analysis and residual analyses. The results showed that the vegetation cover of the Loess Plateau(LP) had exhibited an obvious increasing trend, and the increasing trend was the most significant in summer. The greening area in the Loess Plateau was mainly concentrated in the central and eastern regions.Precipitation had a significant impact on vegetation growth in spring and summer, while it had a small impact in autumn. The effect of temperature on vegetation growth was mainly in spring. Because of the implementation of ecological protection projects, human activities had a positive impact on the vegetation in most areas of the Loess Plateau.