Most of us know what a flash flood is. In late 2022, California and many other areas of the western United States experienced several flash floods that resulted in damaged homes, mudslides, and killed 17 people.
A flash flood, according to NASA, is a rapid rise of water along streams and low-lying land. It typically occurs within six hours of a major rainfall event but can happen even sooner in an intense storm with heavy rain.
Flash droughts are just the opposite, but in many ways, they can be just as damaging. Unlike flash floods, which can develop in hours, flash droughts usually take weeks to months to develop.
But these are not traditional droughts. A drought usually takes years, sometimes a decade, to develop.
The big concern about flash droughts is that communities have little chance to prepare for them. This is unlike the droughts we have seen in the past, where public officials, businesses, and consumers are provided with ample warning signs that drought conditions are growing and becoming more serious.
With a flash drought, there is no warning. In 2017, a flash drought hit Montana and the Dakotas, catching everyone by surprise and causing $3 billion in agricultural losses.
In a step-by-step fashion, here’s how it happened:
These areas of the country experienced a combination of lower-than-normal precipitation and higher temperatures.
These factors reduced overall land moisture.
Under normal conditions, moisture accumulates from rainfall. Plants draw this water through their roots and release water vapor into the air. This is called transpiration.
But with already dry conditions and higher temperatures in Montana and the Dakotas, there was an increase in evaporation and less transpiration. Vegetation could no longer produce all the moisture the atmosphere demanded.
When this happened, reduced moisture caused surface air temperatures to rise, further drying out the soil. This started a domino effect. The area became increasingly warmer and dryer very quickly, resulting in a flash drought.
Flash droughts are relatively new. The term was coined in the early 2000s to draw more attention to this form of rapid – or intensified – drought conditions. It’s a byproduct of climate change. Rising global temperatures due to climate change are behind flash droughts, according to University of Texas professor Zong-Liang Yang. Climate change contributes to the chain reaction just discussed.
One of the big problems that results from a flash drought is that drought conditions can set in very quickly and unexpectedly. During the first part of 2012, areas in the Midwest received near-normal precipitation through May. But by June, temperatures increased, the area became dryer, and a flash drought occurred by August, causing more than $30 billion in damages.
Can we predict flash droughts?
It’s not easy to predict when or where a flash drought might hit. For instance, in the scenario referenced in Montana and the Dakotas, 2017 started out as a typical year as far as temperatures and precipitation were concerned. But unexpectedly and without warning, it was over in a few months.
Even in the best of situations, scientists say nature can be chaotic, which puts limitations on weather predictions. It’s one reason weather forecasters typically do not make weather predictions beyond ten days. There are just too many variables. Further, climate change is making things worse. Due to climate change, most scientists agree, we must expect the unexpected.
So where does water efficiency come into play? Water efficiency is the long-term reduction in water consumption. Waterless urinals are a perfect example. By reducing the consumption of 35,000 gallons of water per urinal per year, we are saving millions of gallons of water throughout the United States.
By using less water, we are not as vulnerable to flash droughts or traditional droughts. We can move water supplies more quickly to where they are needed. This makes the country more water resilient and agile.
Resilience, agility, and water efficiency are the long-term ways we can minimize the impact of flash droughts.
Sources:
What is a flash drought? An earth scientist explains (waterdesk.org)
https://tinyurl.com/2cbrh37x
