China to See More Dry Days, with Larger Extents

China will see more intense drought events in the future 30 years, with high frequency, long duration, and in larger areas, a recent study by Chinese scientists found.

The study, carried out by a team of scientists from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences, found that more intense dryness conditions are projected for China for the period 2016–2050.

Scientists evaluated the intensity, area and duration of future droughts in China for the period 2016–2050, with the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). These are two indices usually adopted to evaluate drought characteristics.

Their study showed an increase in evapotranspiration all over China, and an apparent reduction in precipitation in the southern river basins. “The increase in evapotranspiration plays an important role in the changes of future droughts over the northern river basins and southern river basins,” said SU Buda, a research from XIEG who led the study.

Drought, a period of below-average precipitation in a given region, resulting in prolonged shortages in its water supply, can last for months or years. It may bring substantial impact on the ecosystem and agriculture of the affected region and harm to the local economy.

China has suffered from many long-term droughts with great losses to its economy and society. In 2006, Sichuan Province in southwestern China experienced its worst drought in modern times with nearly 8 million people and over 7 million cattle facing water shortages.

Statistics showed that drought affected about 0.29 million square kilometers every year from the year of 1949 to 2013, causing an annual economic loss of over 32 billion RMB to the country. With the accelerating trend of global warming, more extreme climate events are expected in the future, especially for drought.

The study indicated that more frequent drought events of longer duration are projected in China’s southwestern river basins. For all future droughts, larger extents are projected, especially for events with long-term duration.

“The projected long-term drought events will occur more often and more severe than during the baseline period, and their central locations will likely shift towards Southeast China,” said SU.

Results of the study were published in the recent issue of Climate Dynamics, entitled “Analysis of future drought characteristics in China using the regional climate model CCLM”.