Desertification dynamics in China's drylands under climate change

Abstract

Much of drylands has been hit by land degradation during the recent decades. But whether and how desertification is related to climate change is poorly understood. Here, using the Normalized Difference Vegetation Index (NDVI) time series and climatic variables, we assessed the desertification dynamics over China's drylands from 1982 to 2016 and explored the climate change impacts, with a particular focus on the influence of the 2015/2016 El Niño event. We found a fluctuant downward trend of barren land area from 1982 to the early 2010s, but followed by a sharp increase afterwards. Decrease in precipitation combined with high temperature are major contributors to the barren land expansion. During the 2015/2016 El Niño, the concurrence of severe drought and heat stress gave rise to the most serious land desertification in the record. Hyper-arid and arid drylands are the predominant contributors to the abrupt barren land area increase during 2015/2016. Our findings, therefore, highlight the climate change impacts on dryland desertification processes. Future dryland expansion and accompanying drought stress may exacerbate the risk of land degradation in these regions.