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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SAM Satellite

Sentinel-1 is a two satellite constellation with the prime objectives of land and ocean monitoring. The goal of the mission is to provide C-Band Synthetic Aperture Radar (SAR) data continuity following the retirement of ERS-2 and the end of the Envisat mission.
To accomplish this the satellites carry a C-SAR sensor, which offers medium and high resolution imaging in all weather conditiions. The C-SAR is capable of obtaining night imagery and detecting small movement on the ground, which makes it useful for land and sea monitoring.
Sentinel-1 will work in a pre-programmed operation mode to avoid conflicts and to produce a consistent long-term data archive built for applications based on long time series.
The mission benefits numerous services. For example, services that relate to the monitoring of Arctic sea-ice extent, routine sea-ice mapping, surveillance of the marine environment, including oil-spill monitoring and ship detection for maritime security, monitoring... read more

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The FY-3 series of CMA/NSMC (China Meteorological Administration/National Satellite Meteorological Center) represents the second generation of Chinese polar-orbiting meteorological satellites (follow-on of FY-1 series). The FY-3 series represents a cooperative program between CMA and CNSA (China National Space Administration); it was initially approved in 1998 and entered full-scale development in 1999. Key aspects of the FY-3 satellite series include collecting atmospheric data for intermediate- and long-term weather forecasting and global climate research.
The FY-3 series satellites monitor large-scale meteorological disasters, weather-induced secondary natural hazards and environment changes, and provides geophysical parameters for scientific research in climate change and its variability, climate diagnosis, and predictions. The FY-3 series renders global and regional meteorological information for aviation, ocean navigation, agriculture, forestry, marine activities,... read more

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KOMPSAT-5 is an earth observation satellite equipped with Korea's first all-weather SAR.
The SAR mounted on KOMPSAT-5 emits microwaves to an object on the ground and synthesizes the reflected signal to produce an image. It enables ground observation even during nighttime and poor weather conditions.
As the SAR image can supplement the optical camera, which can record only the visible light spectrum, it is utilized in mutual supplementary operations with the high-resolution optical images of KOMPSAT-3 and KOMPSAT-3A.
KOMPSAT-5 observes the Korean Peninsula four times a day. The transmitted image data are used for public safety, natural disaster forecasts, land/resource management and environmental monitoring.

The primary mission of the KOMPSAT-5 system is to provide high resolution mode SAR images of 1 meter resolution, standard mode SAR images of 3 meter resolution and wide swath mode SAR images of 20 meter resolution with viewing conditions of the incidence... read more

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Resurs-P1 is a Russian Earth observation satellite designed and developed at TsSKB Progress (Progress State Research and Production Space Center) in Samara, Russia. Roskosmos is funding the project (owner and operator of the spacecraft under the Russian Federal Space Program), the commercial data distributor is Sovzond JSC of Moscow. The spacecraft is operated by NTs OMZ (Research Center for Operational Earth Monitoring), Moscow, Russia.

Resurs-P1 is meant to replace the Resurs-DK, a previous generation spacecraft, which was launched on June 15, 2006.

Resurs-P carries the Geoton-L1 hyperspectral imaging payload as the main imaging instrumet. The optics have an apperture of 0.5 m and provides images with a ground resolution of 1.0 m in panchromatic mode and a resolution of 3 to 4 m in color mode. The Geoton-L1 system has 7 passbands and a 216-channel hyperspectral imager.

Aditionallym the KShMSA wide field multispectral camera is... read more

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The Proba-V satellite may only be slightly larger than a washing machine, but it is tasked with a full-scale mission. This miniature satellite is designed to map land cover and vegetation growth across the entire globe every two days. Over the last decade 'Proba' has become synonymous with small high-performance satellites, designed around innovation. The two previous satellites in the series were demonstration missions to give promising technologies an early chance to fly in space. They were overseen by ESA’s Directorate of Technical and Quality Management. Although designed as a demonstration mission, the success of the first Proba satellite led to it being operated as an Earth observation Third Party Mission. Proba-1 carries a high-resolution imaging spectrometer. 

The 'V' stands for Vegetation – a lighter but fully functional redesign of the ‘Vegetation’ imaging instrument previously flown on France’s full-sized Spot-4 and Spot-5 satellites.

Launched on 7 May 2013... read more

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Gaofen-1 (gao fen = high resolution) is the first of a series of high-resolution optical Earth observation satellites of CNSA (China National Space Administration), Beijing, China. The civilian HDEOS (High-Definition Earth Observation Satellite) program was proposed in 2006, it received government approval and was initiated in 2010. China plans to launch six HDEOS spacecraft between 2013 and 2016. The major users of the observation data will be the Ministry of Land and Resources, Ministry of Environmental Protection, and the Ministry of Agriculture.
The GF-1 spacecraft was launched on April 26, 2013 on a CZ-2D (Long March -2D) vehicle from the JSLC (Jiuquan Satellite Launch Center) in northwest China.

PMC (PAN and Multispectral camera)
WFI (Wide Field Imager)

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Landsat 8 launched on February 11, 2013, from Vandenberg Air Force Base, California, on an Atlas-V 401 rocket, with the extended payload fairing
 (EPF) from United Launch Alliance, LLC. The Landsat 8 satellite payload consists of two science instruments—the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). These two sensors provide seasonal coverage of the global landmass at a spatial resolution of 30 meters (visible, NIR, SWIR); 100 meters (thermal); and 15 meters (panchromatic).
Landsat 8 was developed as a collaboration between NASA and the U.S. Geological Survey (USGS). NASA led the design, construction, launch, and on-orbit calibration phases, during which time the satellite was called the Landsat Data Continuity Mission (LDCM). On May 30, 2013, USGS took over routine operations and the satellite became Landsat 8. USGS leads post-launch calibration activities, satellite operations, data product generation, and data archiving at the Earth Resources... read more

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Launched in December 2011, Pleiades is a constellation of two very-high-resolution satellites capable of acquiring imagery of any point on the globe in under 24 hours for civil and military users.
Pleiades has been observing and mapping Earth’s surface at a resolution of just 70 cm every day since December 2011. Comprising the Pleiades 1A and Pleiades 1B satellites, this space imaging system complements the capabilities of the SPOT satellites, which have a wider field of view than Pleiades but lower spatial resolution. What’s more, as Pleiades 1A and 1B are in the same orbit, together they can image anywhere on Earth in less than 24 hours. Pleiades imagery is used for both civil and military applications, for example to track urban expansion, monitor the planet’s active volcanoes or assist road and railway routing, and to locate adversaries’ military installations for mission planning. Pleiades’ key asset is an extremely sensitive optical instrument that reduces the exposure... read more

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SJ-9 (Shi Jian = Practice) is a technology demonstration formation flight mission of CNSA (China National Space Administration), consisting of two minisatellites of different sizes and capabilities, SJ-9A and SJ-9B. The overall mission concept is to demonstrate the functionality of a range of newly developed formation flying techniques and components and to validate the formation flight GNC (Guidance, Navigation and Control) algorithms and strategies of the system configuration.
SJ 9A is based on the CAST-2000 bus. It conducts in-orbit experiments for electric propulsion, high-precision- and high-stability control systems, high-efficienent power supply and advanced thermal control technology. The satellite features also instruments for Earth observation and component tests of indigenously developed technology.

Instruments: High-performance small camera
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VRSS-1 is Venezuela's first remote sensing satellite.
On May 26, 2011, a contract for the manufacture and launch of the VRSS-1 spacecraft was signed in Caracas, Venezuela, between the government of Venezuela (the Ministry of People’s Power for Science, Technology and Intermediate Industries) and CGWIC (China Great Wall Industry Corporation), a subsidiary of CASC (China Aerospace Science & Technology Corporation).
After launch, the VRSS-1 satellite was renamed in honor of Sebastián Francisco de Miranda (1750-1816), a Venezuelan revolutionary hero, known as ‘Generalissimo’ Francisco de Miranda, who had planned the independence of the Spanish colonies in South America.
Partner organizations in the VRSS-1 program: ABAE is the Space Agency of Venezuela, subordinated and funded by the Venezuelan Ministry of People’s Power for Science, Technology and Innovation (MPPCTI). ABAE is in charge of in-orbit operations, management and application of the VRSS-1 satellite mission... read more

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