Do your droughts take too long to dry out the soil? Try the new and improved Flash Droughts!
Flash droughts have always been around – the term refers to a drought that dries out the landscape at some point in five days – and they don’t seem to be getting more frequent right now.
What they are do, gets faster.
Researchers from the University of Texas at Austin, Hong Kong Polytechnic University and Texas Tech University found that although the number of flash droughts has remained stable over the past two decades, more of them happen faster. Globally, the fastest-occurring flash droughts — sending areas into drought conditions in just five days — have increased by around 3 to 19 percent. And in places especially prone to sudden droughts — like South Asia, Southeast Asia, and central North America — that increase is around 22 to 59 percent.
Rising global temperatures are likely to blame for the faster onset, said co-author and UT Jackson School professor Zong-Liang Yang, who added that the study results point to the importance of understanding flash droughts and preparing for their effects.
Flash droughts are relatively new to science, with advances in remote sensing technology over the past two decades helping to reveal instances of rapid soil drying. This serves as a tell-tale sign of the onset of a flash drought and can cause drought conditions to appear out of the blue.
As the name suggests, flash droughts are short-lived, usually lasting only a few weeks or months. But when they occur during critical growth periods, they can spell disaster. For example, in the summer of 2012, a flash drought in the central United States caused the corn crop to wilt, resulting in losses estimated at $35.7 billion.
In this study, scientists analyzed global hydroclimate datasets that use satellite-based soil moisture measurements to capture a global picture of flash drought and its evolution over the past 21 years. The data showed that about 34-46% of flash droughts occurred in about five days. The rest emerges within a month, with more than 70% developing within half a month or less.
When they looked at droughts over time, they noticed that flash droughts happened faster.
The study also revealed the importance of humidity and variable weather conditions, with sudden droughts becoming more likely when there is a shift from wet to arid conditions. This makes regions that experience seasonal variations in humidity — such as Southeast Asia, the Amazon Basin, and the East Coast and Gulf Coast of the United States — drought hotspots.
“We need to pay special attention to vulnerable regions with a high probability of simultaneous soil drought and atmospheric aridity,” Wang said.
Mark Svoboda, director of the National Drought Mitigation Center and originator of the term “flash drought,” said advances in drought-sensing technology and modeling tools — such as those used in this study — have led to a catch. growing awareness of the influence and impact of flash droughts. He said the next big step is to translate that knowledge into planning on the ground.
“You can go back and watch this drought evolve in 2012 and then compare it to the evolution of this tool,” said Svoboda, who was not part of the study. “We really have the ground well prepared to do a better job of monitoring these droughts.”
I think this means, from an agriculture point of view, that it is very possible that without maintaining a reserve of water against sudden droughts, a crop could be destroyed before it is time to organize an intervention emergency. As with so many other aspects of living with climate change, it seems to me that the first step is to create a society that values storing resources as needed, rather than using as much as we produce, as and as we produce it. This is not a guaranteed solution to all problems, but it East a way to ensure that you probably have the time and energy to find a more suitable solution to your problem, since you are less likely to focus on mere survival.
Luck smiles on the prepared.