Dynamic responses of ecological vulnerability to land cover shifts over the Yellow river Basin, China

Ecological protection and high-quality development of the Yellow River Basin (YRB) aroused profound concerns from China Central Government and is now a major national strategy. However, ecological degradation is still a pressing issue for fluvial ecological conservation. Recent years witnessed widespread implementation of ecological projects such as “Grain to Green Project” (GGP) and “Return Grazing land to Grassland Project” (RGGP) which aim to improve the ecological environment of the YRB. While dynamic responses of ecological vulnerability to land cover changes are poorly understood under climate changes and human activities. Here we use the “exposure-sensitivity-resilience” sliding ecological vulnerability evaluation framework to quantify the Ecological Vulnerability Index (EVI) and scrutinize dynamic responses of EVI to land use changes over the YRB. We find slight ecological degradation with increased EVI across the YRB from 1986 to 2013, and the highest ecological vulnerability in summer. Meanwhile, regions with degraded ecological status are found mainly along the main stream of the YRB. Besides, the gravity centers of EVI cluster mainly in the central and western parts of the YRB and correspond to four ecological conditions, i.e. unstable ecological condition, moderate ecological variability, ecological restoration, and moderate ecological variability. Furthermore, we identify a higher ecological degradation rate of croplands than non-croplands, while evidently lower ecological degradation rate of grasslands than non-grasslands. The GGP and RGGP projects have improved the ecological environment of the YRB, but have not reversed the degrading tendency of the ecological environment across the YRB.