Lake Chad has shrunk dramatically over the last four decades due to a decrease in rainfall and an increase in the amount of water used for irrigation projects. Its surface area was 25 000 sq km in the early 1960s, compared with 1350 sq km in 2001. Image acquired 19 December 2007 by the MERIS (Medium Resolution Imaging Spectrometer) instrument aboard ESA’s Envisat satellite. Image: ESA, CC BY-SA 3.0 IGO.


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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The Sentinel-6 Michael Freilich satellite was launched into orbit on November 21, 2020. The launch was a culminated European-American effort that involved organisations from both sides of the atlantic. The European Space Agency (ESA), the European Organisation for the Exploitation of Meterological Satellites (EUMETSAT), the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA) and the National Centre for Space Studes (CNES) all collaborated together to make the launch of Sentinel-6 Michael Freilich a reality.​ The Sentinel-6 Michael Freilich satellite is the first of the Sentinel-6 satellites. An identical satellite, Sentinel-6B will follow in 2025. At an altitude of 1336 km the Sentinel-6 Michael Freilich satellite will use instruments on board to provide highly accurate measurements of the sea level in an effort to... read more

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The Argentinean Microwaves Observation Satellite 1B (SAOCOM 1B) was launched into orbit on August 30, 2020 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, United States of America. Developed by the National Argentinean Space Commission (CONAE) in corporation with the Italian Space Agency (ASI), this new satellite joined SAOCOM 1A and four Italian COSMO-SkyMed to complete the Italian-Argentinean Satellite System for Emergency Management (SIASGE). The SAOCOM 1B satellite orbits at 620 km above the earth's surface and is fitted with a Synthetic Aperture Radar (SAR) sensor that makes use of microwaves in the electromagnetic L-band. The spatial resolution of its imagery ranges between 10 and 100 meters. The data collected by SAOCOM 1B helps monitor climatological disasters (forest fires, glacial lake outbursts, droughts) and hydrological disasters (landslides and floods).


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MetOp-C is the third and last satellite of the MetOp series that forms the space segment of the EUMETSAT Polar System (EPS).
MetOp (Meteorological Operational) is Europe's first polar-orbiting operational meteorological satellite. It is the European contribution to the Initial Joint Polar System (IJPS), a co-operative agreement between Eumetsat and the US National Oceanic and Atmospheric Administration (NOAA) to provide data for climate and environmental monitoring and improved weather forecasting.
MetOp-A (launched on 19 October 2006), MetOp-B (launched on 17 September 2012) and MetOp-C (launched 7 November 2018) are in a lower polar orbit, at an altitude of 817 kilometres, to provide more detailed observations of the global atmosphere, oceans and continents. The three satellites will operate in unison for as long as Metop-A's available capacities bring benefits to users. NOAA still continues to operate its mid-afternoon orbit satellite service as part of the Polar Orbit... read more

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NovaSAR-1 was launched into orbit on September 16, 2018 from Satish Dhawan Space Centre in Sriharikota, India. It was developed by the United Kingdom Space Agency (UKSA) in cooperation with the Indian Space Research Organisation (ISRO), the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Department of Science and Technology-Advanced Science and Technology Institute (DOST-ASTI) of the Republic of the Philipines. NovaSAR-1 orbits at 583 km above the earth's surface and is fitted with a Synthetic Aperture Radar (SAR) sensor that makes use of microwaves in the electromagnetic S-band. The spatial resolution of its imagery ranges between 6 and 30 metres. The data collected by NovaSAR-1 helps monitor climatological disasters (forest fires and droughts) and hydrological disasters (floods).

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The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) mission measures the temperature of plants to better understand how much water plants need and how they respond to stress. ECOSTRESS is attached to the International Space Station (ISS) and collects data over the conterminous United States (CONUS) as well as key biomes and agricultural zones around the world and selected FLUXNET (http://fluxnet.fluxdata.org/about/) validation sites. A map of the acquisition coverage can be found on the ECOSTRESS website (https://ecostress.jpl.nasa.gov/science).

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Carrying a suite of cutting-edge instruments, Sentinel-3 will measure systematically Earth’s oceans, land, ice and atmosphere to monitor and understand large-scale global dynamics. It will provide essential information in near-real time for ocean and weather forecasting.
The mission is based on two identical satellites orbiting in constellation for optimum global coverage and data delivery. For example, with a swath width of 1270 km, the ocean and land colour instrument will provide global coverage every two days. Sentinel-3B was launched on 25 April 2018.
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GOES-17 (formerly GOES-S) is the second of the current generation of weather satellites operated by the National Oceanic and Atmospheric Administration (NOAA). The four satellites of the series (GOES-16, -17, -T, and -U) will extend the availability of the GOES (Geostationary Operational Environmental Satellite system) until 2036 for weather forecast and meteorology research. The satellite was built by Lockheed Martin, was based on the A2100A platform, and will have an expected useful life of 15 years (10 years operational after five years of standby as an on-orbit replacement). The satellite was launched on 1 March 2018 and reached geostationary orbit on 12 March 2018. In May 2018, during the satellite's testing phase after launch, a problem was discovered with its primary instrument, the Advanced Baseline Imager. GOES-17 became operational as GOES-West on 12 February 2019. GOES-17 is currently operating alongside GOES-15 but will replace it in July 2019.

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Cartosat-2 is an advanced remote sensing satellite with a single panchromatic camera (PAN) capable of providing scene-specific spot imageries for cartographic applications. The camera is designed to provide imageries with better than one meter spatial resolution and a swath of 10 km. The satellite will have high agility with capability to steer along and across the track up to + 45 degrees. It will be placed in a sun-synchronous polar orbit at an altitude of 630 km. It will have a revisit period of four days. The re-visit can be improved to one day with suitable orbit manoeuvres.

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The Sentinels are a fleet of satellites designed specifically to deliver the wealth of data and imagery that are central to the European Commission’s Copernicus programme.
Sentinel-2 carries an innovative wide swath high-resolution multispectral imager with 13 spectral bands for a new perspective of our land and vegetation. The combination of high resolution, novel spectral capabilities, a swath width of 290 km and frequent revisit times provides unprecedented views of Earth.
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