Flash Droughts in India

Introduction

        According to UN, Drought is defined as an extended period – a season, a year, or several years – of deficient rainfall relative to the statistical multi-year average for a region.

Historical Background:

      In 1979, India faced a severe flash drought, affecting about 40% of the country and taking a toll on agriculture.

  • that the big granaries of Uttar Pradesh and Andhra were affected
  • the country suffered a loss of about ₹5,000 crores.

Current Relevance:

     A new study has now pointed out that India could experience more such flash droughts by the end of this century.

Conditions for Drought:

  • Climatic factors like high winds,temperatures and low relative humidity.
    • These factors can aggravate the severity of the drought event.
  • As per the Manual for Drought Management 2016,
    • drought is declared considering following two indicative factors:
      • The extent of rainfall deviation (depreciation)
      • The consequent dry spell
  • IMD declares a year to be a drought year,
    • in case the area is affected by moderate and severe drought,
    • either individually or together
    • for 20-40% of the total area of the country.
  • A seasonal deficiency during the South-West monsoon season in the country as a whole should be 10% or more.
  • A drought year is called ‘All India Severe Drought Year’ if its spatial coverage is more than 40% of the total area.
  • As reported by the Drought Early Warning System (DEWS),
    • a real-time drought monitoring platform,
    • in March 2019, about 42% of India’s land area is under drought
    • with 6% exceptionally dry (four times the special extent of the drought last year.)
  • Andhra Pradesh, Bihar, Gujarat, Jharkhand, Karnataka, Maharashtra, parts of the North-East, Rajasthan, Tamil Nadu and Telangana are the worst hit.
    • (home to 40% of the country’s population, i.e 500 million people

Flash droughts:

  • Flash droughts are those that occur very quickly, with soil moisture depleting rapidly.
  • Drought conditions take months, but these happen within a week or in two weeks’ time.
  • Several factors including atmospheric anomalies, anthropogenic greenhouse gas emissions play an important role.

Cycle of extremes: On droughts and floods:

  • Long periods of drought and then a sudden bout of excessive rainfall, bringing floods has become a hallmark of Indian Monsoon for the last few years.
  • A common feature of drought and floods with coexistence poses a potent threat that cannot be eradicated but has to be managed.
  • The ongoing climate change has caused a significant increase in global temperature
    • this can lead to more and more flash droughts in the coming years.
  • If  the ‘Paris Agreement’ goals and limit global warming to well below 2 degrees C, can be met –
    • the numbers and frequency of the projected flash droughts may go down,
  • The team of IIT Gandhinagar analysed the major flash droughts that occurred from 1951 to 2016 in India.
    • Duration, intensity, and area of the flash droughts were studied and an overall severity score was given.
    • The top five flash droughts based on the overall severity score occurred in 1951, 1979, 2009,1986 and 2005.

Impacts created by Droughts:

  • Drought causes economic, environmental and social impacts.
    • The first-round impacts on agriculture and water resources account for a significant proportion of drought impacts.
    • Others are follow-up impacts on the population immediately affected by drought,
    • such as farmer incomes and the health, nutrition, and education status of drought-affected populations.
    • A third level is on downstream activities, such as industries reliant on agriculture and water.
    • Longer-term impacts on growth, trade, foreign exchange, fiscal balance, and so on.

Drought Management:

  • Crop Weather Watch Group (CWWG), evaluates information and data furnished by IMD and other scientific and technical bodies
    • to determine the likely impact of meteorological events and other environmental parameters on agriculture.
    • has planned future studies that will consider the flash-drought prediction ahead of time using operational meteorological forecasts.
    • this will help manage irrigation water demands and avoid considerable losses in agriculture.
    • uses a Community Earth System Model which simulates the
      • summer monsoon precipitation,
      • sea surface temperature,
      • role of El Nino Southern Oscillation,
      • air temperature over India.
    • The analysis showed a considerable rise in the frequency of extremely dry and hot years in the coming three decades.
    • also examined
      • the role of greenhouse gas emissions,
      • industrial aerosols,
      • land-use/land-cover change.
    • The frequency of concurrent hot and dry extremes is projected to rise by about five-fold,
      • causing an approximately seven-fold increase in flash droughts like 1979 by the end of the 21st century.
    • They conclude that this increased frequency of flash droughts can have deleterious implications for crop production, irrigation demands and groundwater abstraction in India.

Way Forward:

  • The United Nations Development Programme (UNDP) launched the Integrated Drylands Development Programme (IDDP)
    • with the overall goal to strengthen resilience by working on the twin vulnerabilities of poverty and unsustainable land management in the drylands.
  • The United Nations Office for Disaster Risk Reduction (UNISDR) developed a Drought Risk Reduction framework
    • that 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.

Conclusion

                   There is a need for a more organized and common conceptual framework for assessing drought risk and for analysing the “Benefits of Action and Costs of Inaction” (BACI).
                   The framework is set out within the model for the overall process of developing a National Drought Management Policy, which was codified by the World Meteorological Organization (WMO) and the Global Water Partnership (GWP) in their 2014 National Drought Management Policy Guidelines.

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