Drought

Definition

Drought may be considered in general terms a consequence of a reduction over an extended period of time in the amount of precipitation that is received, usually over a season or more in length. It is a temporary aberration, unlike aridity, which is a permanent feature of the climate. Seasonal aridity (i.e., a well-defined dry season) also needs to be distinguished from drought. It should be noted that drought is a normal, recurrent feature of climate, and it occurs in virtually all climatic regimes (UNDDR).

Facts and figures

Droughts are often predictable: periods of unusual dryness are normal in all weather systems. Advance warning is possible (WHO).

By 2025, 1.8 billion people will experience absolute water scarcity, and 2/3 of the world will be living under water stressed conditions (UNCCD).

Drought can be defined according to meteorological, agricultural, hydrological and socio-economic criteria.

  • Meteorological, when precipitation departs from the long-term normal
  • Agricultural, when there is insufficient soil moisture to meet the needs of a particular crop at a particular time. Agricultural drought is typically evident after meteorological drought but before a hydrological drought
  • Hydrological, when deficiencies occur in surface and subsurface water supplies
  • Socio-economic, when human activities are affected by reduced precipitation and related water availability. This form of drought associates human activities with elements of meteorological, agricultural, and hydrological drought (FAO).

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Related content on the Knowledge Portal

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    In order to evaluate the capability of NOAA-AVHRR data for drought monitoring in the northwest of Iran having cold semi-arid climate, a study plan was designed involving the production of normalized difference vegetation index (NDVI) and vegetation condition index (VCI) indices and correlating their values to precipitation data. Raw AVHRR images were processed and geometric and radiometric corrections were performed. Seven-day maximum NDVI maps were produced and VCI was calculated using the maximum and minimum NDVI values for the same time period. Precipitation statistics from 19 synoptic meteorological stations were collected. The study covered a five-year time period with three consecutive months in the growing season. Pearson correlation was performed to correlate NDVI and VCI values to precipitation data. Different time lag schemes were tried and the highest correlation coefficients (r values) were obtained while correlating NDVI and VCI to three-month (current…

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  •  

    Uruguayan economy is largely dependent, directly or indirectly, on agriculture (crops and livestock). Production in Uruguay is based on the highly fertile soils of the Pampas, an ecosystem in which native temperate and subtropical grasslands are used for livestock production or have been converted to improved pastures (grasses/legumes) and to croplands. Interannual and interseasonal climatic fluctuations in Uruguay result in high variability in crop and pasture production with frequent negative consequences on the economy.

  • The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) states that the El Niño in the Equatorial Pacific continues to sustain its moderate strength and is recently in his mature stage. Gradual decrease in sea surface temperature is expected but still within the El Niño threshold and likely to last up to June 2010. To date, Regions I, II and XII have been experiencing dry spell conditions such as drought, increased temperature, decreased rainfall and water supply which affected agricultural productions such as rice, corn and vegetables in 165,071 hectares with estimated production loss of PhP2.4B.

    Source GLIDEnumber

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  • From Oct 2009 to January 2010 Dominica southward to Trinidad experienced moderately to extremely dry conditions for the four month period. St. Lucia, Barbados, St. Vincent and the Grenadines and Grenada in particular were extremely dry. Water levels are dropping quickly in several Caribbean countries, prompting officials to limit availability and impose restrictions as the region enters its dry season.

    Source: GLIDEnumber

  • Drought induced by El Nino has caused hunger in the departments of Choluteca, Valle La Paz, Lempira, Intibuca, El Paraiso y el Sur de Francisco Morazan. The government is supplying the communities with basic grains.

    Source: www.glidenumber.net

  • The state of emergency has been declared for the coastal Province of Manabi as drought is affecting food security and daily lives.

    Source: www.glidenumber.net

  • A severe drought is affecting indigenous communities in the department of Chuquisaca in the Chaco region. ECHO is providing 150.000 euros to help around 390 families.

    Source: http://www.glidenumber.net/glide/public/search/details.jsp?glide=18928.

     

     

     

  • Sources from IRIN, click here

  • NAIROBI, 17 August 2009 (IRIN) - Some rains have fallen in northern Somalia, but this has not stopped an exodus of drought-affected people from rural areas to urban centres in Somaliland, local officials said.

    "We know that hundreds of thousands have [been] displaced to urban centres," said Abdihakim Garaad Mohamoud, Deputy Minister at the Somaliland Ministry of Resettlement, Reintegration and Rehabilitation.

    "Every city in Somaliland has a huge number of displaced people because of the recent drought," he added. "It has affected 60 percent of the rural population, whether they are pastoralists or agro-pastoralists. From east to west, south to north, every place in Somaliland has been affected."

    Across towns in the self-declared republic, such as Burao, Berbera, Erigavo, Las’anod and Badhan, temporary shelters have sprouted as rural…

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  • A drought-like situation is developing in parts of India and Bangladesh. The rain deficit is affecting water supplies and farmers in the affected areas of both countries are reportedly facing electricity and fuel shortages or higher costs for pumping water for irrigation.

    Source : Glide number

    Ressources from OCHA/Reliefweb, click here

Term Parents

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