This story is part of
Science for All newsletter
SHOW MORE 59 STORIES

Science for All | What are flash droughts?
Premium

The Hindu’s weekly Science for All newsletter explains all things Science, without the jargon.

May 10, 2023 05:15 pm | Updated May 11, 2023 11:06 am IST

(This article forms a part of the Science for All newsletter that takes the jargon out of science and puts the fun in! Subscribe now!)

Droughts are periods of continuous water deficit, often caused by a lack of precipitation in a given area. They have a significant adverse impact on the regional environment and economy. A flash drought is a rapid onset or intensification of drought. 

Low rates of precipitation, along with abnormally high temperatures, winds, and solar radiation are factors that can rapidly alter local climate, leading to flash drought. It can also be linked to climatic patterns like La Niña. 

According to scientists, an early warning sign of flash droughts is evapotranspiration, which leads to a decrease in soil moisture. Evapotranspiration is the process of water transfer from land to atmosphere by evaporation from soil and transpiration from plants. 

A study, published in the journal Science on April 13, reported that climate change is intensifying flash droughts worldwide. In the last 64 years, more than 74% of the world’s regions identified by the U.N. Intergovernmental Panel on Climate Change’s ‘Special Report on Extreme Events’ have experienced flash droughts. This transition will only expand and the report calls for urgent adaptation to faster-onset droughts in a warmer future. 

The study divided sub-seasonal droughts into flash droughts and slow droughts. The onset speed of both is measured by declining soil moisture rate. Flash droughts usually last around 30-45 days while slow droughts last 40-60 days. Increasing drought onset speed is primarily due to intensifying rainfall deficit and increasing evapotranspiration caused by climate change, the study noted. Evapotranspiration quickly dries the soil, creating ideal conditions for heat waves, leading eventually to the rapid onset of drought conditions. 

Flash droughts may lead to irreversible changes in terrestrial ecosystems. In such conditions, ecosystems may not have enough time to adapt to a large water deficit and extreme heat, leading to lower productivity. Flash droughts can also significantly challenge drought monitoring and prediction.

From the Science pages

FDA approves first vaccine for respiratory syncytial virus

Bengaluru scientists help find new kind of molecular motor

Wastewater study detects a large, silent wave in Bengaluru

Question Corner

Have scientists detected a nearby black hole devouring a star? Find out here.

Flore and Fauna

Extent of role dust plays in nourishing ocean ecosystems investigated

The ordeal of raising a feathered family

Conservation efforts bear fruit as survey finds record gharials in Bihar’s Gandak river

A curious case of human-elephant cohabitation in Munnar

Top News Today

Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in

Comments

Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.