Environment

Flash droughts: Why early-warning, mitigation techniques are needed

Flash droughts have severe impacts, occur when regular droughts rapidly intensify

 
By DTE Staff
Last Updated: Wednesday 04 March 2020
Droughts were the most complex and least understood of all climate extremes Photo: Pixabay

A new study on flash droughts published in journal Nature Climate Change on March 2, 2020 explored the impact of this extreme climate phenomenon. The study explored current knowledge about flash droughts and existing processes to predict and mitigate their occurrence.

Flash droughts could occur in weeks and stay on for months (subseasonal to seasonal time periods), according to the study conducted by a multi-institutional collaboration, including the Lawrence Livermore National Laboratory.

Flash droughts had severe impacts and occurred when regular drought conditions rapidly intensified. This made it more urgent to accurately identify the physical processes behind their origins.

Early-warning systems (EWS) that could identify trends in climate and sources of water were needed to detect the emergence or probability of the occurrence of flash droughts, according to the study.

Droughts were the most complex and least understood of all climate extremes. They could extend to entire regions from a few kilometres and continue for decades, according to the study.

The need for EWS and drought monitoring was “the foundation of effective, proactive drought policy,” according to Angeline Pendergrass, a climate scientist and the study’s lead author.

There was little known about flash droughts — or ‘hidden hazards’ — when compared to research available on long-term droughts, according to the study, which cited the example of a flash drought in the Midwest region of the United States in 2012.

The flash drought doubled the extent of abnormally dry conditions to more than 60 per cent in August that year from 30 per cent in May.

The significant impact this caused in agriculture caught the attention of the US government, according to the study.

Flash droughts were the focus of research in China and Australia too, the study noted.

In 2018, one such flash drought de-vegetated the entire landscape and caused livestock numbers to dip to their lowest in a century in Australia’s south Queensland, according to the study.

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