Located in the far outback of the Eurasian continent, the Xinjiang Autonomous Region of China is a typical arid region with a fragile ecological environment and system, sensitive to climate change. But recent study shows that this area is getting more and more humid with the intensifying hydrology cycle caused by global warming.
Through analysis on the observation data from 1961 to 2015, CHEN Yaning and his team with the Xinjiang Institute of Ecology and Geography found that, Xinjiang showed a wetting trend during this period.
“The mean annual air temperature in Xinjiang increased significantly between 1961 and 2015. This warming trend started to accelerate during the late 1980s and then showed a sharp increase in 1997, after which it remained stable,” said CHEN.
Regional precipitation exhibited a significant increasing trend and the region gets wetter. Average annual precipitation showed a sharp increase in 1987 and the 1990s was the most humid decade on record, according to the research.
However, the year 1997 witnessed a clear reversal of this trend from wetting to drying, with the continual temperature rising and intensifying evapotranspiration and precipitation decrease. The intensified warming and diminished precipitation in Xinjiang over the past two decades have resulted in SPEI-drought severity, affecting over 70 per cent of the region.
Soil humidity suffered a tumbling decrease starting from the mid 1990s, with a mean decrease of over 40 per cent. Vegetation cover showed an increasing trend from 1982 to 1997, and then decreased significantly after 1997.
“The intensified warming and diminished precipitation in Xinjiang over the past two decades have somewhat increased the drought severity in the region. More severe droughts have adverse ecological consequences related to enhance soil moisture loss and decreased vegetation cover,” said CHEN.
Their research was published on Science of the Total Environment entitled “Multi-scale assessments of droughts: A case study in Xinjiang, China”.