Researchers at The University of Texas at Austin, The Hong Kong Polytechnic University and Texas Tech University found that although the number of flash droughts has remained stable during the past two decades, more of them are coming on faster. Globally, the flash droughts that come on the fastest -- sending areas into drought conditions within just five days -- have increased by about 3%-19%. And in places that are especially prone to flash droughts -- such as South Asia, Southeast Asia and central North America -- that increase is about 22%-59%.
Rising global temperatures are probably behind the faster onset, said co-author and UT Jackson School Professor Zong-Liang Yang, who added that the study's results underscore the importance of understanding flash droughts and preparing for their effects.
"Every year, we are seeing record-breaking warming episodes, and that is a good precursor to these flash droughts," he said. "The hope and purpose [of this research] is to minimize the detrimental effects."
The research was published in Nature Communications. The study was led by doctoral student Yamin Qing and Professor Shuo Wang, both of The Hong Kong Polytechnic University.
Flash droughts are relatively new to science, with the advancement of remote sensing technology during the past couple of decades helping reveal instances of soil rapidly drying out. This serves as the telltale sign of the onset of a flash drought and can make drought conditions appear seemingly out of the blue.