India among global flash drought hotspots from 1980-2015: Study


    In News

    • A study identified rapid drought intensification across India , United States, Brazil, southern Africa, Spain, western Russia and Australia as well.

    Flash Drought

    • It is the rapid onset or intensification of drought and is set in motion by lower-than-normal rates of precipitation
      • Accompanied by abnormally high temperatures, winds, and radiation. 
      • Together, these changes in weather can rapidly alter the local climate.
    • The highest frequency of flash drought occurrence was primarily found within the tropics and subtropics.
      • They include a large portion of Brazil, the Sahel, the Great Rift Valley and India.
      • With composite flash drought occurrence within the 36-year time period (1980-2015) of analysis.
      • Additional areas within the tropics that had lesser, but notable flash drought occurrences included 
        • central Mexico, the Indochinese Peninsula, and northern Australia.
      • In the mid-latitudes, local hotspots of flash drought occurrence (10-20 per cent) exist across 
        • the central United States, Iberian Peninsula, Asia Minor, southwestern Russia, and northeastern China.

    Study published in the Journal Nature Communications

    • Selected Regions:
      • Study regions are over global hotspots where flash drought occurred in more than 30 per cent of the study years (1980–2015)
      • The study identified rapid drought intensification across the United States, Brazil, southern Africa, Spain, western Russia and Australia.
    • Key drivers:
      • Rapid drought intensification occurs due to 
        • a critical lack of precipitation and 
        • increased evaporative demand.
    • In India:
      • A majority of the flash drought events occurred during the monsoon season.
        • Especially across the central, northwest and northeast regions of the country.
      • These regions experience their peak frequency at the beginning of their respective monsoon seasons
        • Primarily between May and September from 1980-2015.
    • In Sahel Region:
      • The flash drought likely occurred during May-June, and was associated with increasing climatological rainfall.
      • Especially if the onset of Inter-Tropical Convergence Zone (ITCZ) induced and monsoon rainfall was delayed or significantly decreased.
    • In Amazon:
      • Flash drought occurs most often in the dry season (July-September). 
      • Mainly due to the combined effect of 
        • increased evaporative demand, 
        • limited rainfall and 
        • increased evapotranspiration resulting in rapid soil moisture depletion.

    Evaporative demand 

    • It is a measure of the extent to which the environment tries to evaporate water. 
    • Changes in evaporative demand affect freshwater supplies and impact agriculture.

    Impact on Agriculture

    • Flash droughts can develop in only a few weeks, they create impacts that are difficult to prepare for and mitigate. 
      • Even when environmental conditions seem unfavourable for rapid drought development.
      • A persistent lack of rainfall coupled with hot weather can create flash drought development with its associated impacts.
    • Areas under the Flash drought hotspots
      • the corn belt across the mid-western United States, 
      • barley production in the Iberian Peninsula,
      • the wheat belt in western Russia, 
      • wheat production in Asia Minor, 
      • rice-producing regions in India and the Indo-china Peninsula, 
      • maize production in northeastern China and 
      • sorghum production across the Sahel.
    • Trends
      • About 10-15 percent of areas under cultivation of rice and maize were affected during the monsoon seasons in India between 1951 and 2018.
    • Future Implications
      • The researchers said that the trend only applies to the 36 year period i.e between 1980–2015 and 
      • Do not indicate that these trends will extend into the future.

    Way Forward and Conclusion

    • Limiting Global Warming
      • By limiting global warming to well below 2 degrees C, the numbers and frequency of the projected flash droughts may go down.
    • Early warning Systems
      • Operational meteorological forecasts will help manage irrigation water demands and avoid considerable losses in agriculture.

    International Efforts

    • Integrated Drylands Development Programme (IDDP): 
      • Launched by the United Nations Development Programme (UNDP) 
      • Goal: To strengthen resilience by working on the twin vulnerabilities 
        • poverty and 
        • unsustainable land management in the drylands.
    • Drought Risk Reduction framework:
      • Developed by the United Nations Office for Disaster Risk Reduction (UNISDR) 
      • It takes an integrated development approach and provides a comprehensive framework for both higher-level and local action.
    • The Integrated Drought Management Programme (IDMP) and its partners have adopted three pillars of drought management:
      • Drought monitoring and early warning systems 
        • to determine drought status.
      • Vulnerability and impact assessment 
        • to determine who and what are at risk and why.
      • Mitigation, drought preparedness, and response 
        • to set out actions and measures to mitigate drought impacts and to prepare to respond to drought emergencies.

    Source: DTE