Drought

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.

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).

Related content

SAM Satellite

Today, weather satellites scan the whole Earth, meaning not a single tropical storm or severe weather system goes undetected. The early detection and warnings they provide have saved thousands of lives.
Meteosat data is of unique value to nowcasting of high impact weather in support of safety of life and property.
It has been shown to improve weather forecasts and severe weather warnings which, in turn helps limit damage to property and benefits industry e.g. transport, agriculture and energy.
Meteosat-11 is the prime operational geostationary satellite, positioned at 0 degrees and providing full... read more

Launch date:
16/07/2015

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-... read more

Launch date:
23/06/2015

KOMPSAT-3A is the world’s first civilian satellite that is equipped with a high-resolution, infrared(MWIR) sensor which enables nighttime observation. It also provides the optical images with high resolution of 50 cm or less for the second in the world following the US.
The technology of improving the optical image quality by 30% or more without degradation using diagonal data to provide 38-cm-class images was developed for the second following the EU.
The high-resolution electro-optical spaceborne camera AEISS-A(Advanced Earth Imaging Sensor System-A) developed by... read more

Launch date:
26/03/2015

CBERS is a cooperative program between CAST (Chinese Academy of Space Technology) of the People's Republic of China, and INPE (Instituto de Pesquisas Espaciais) of Brazil (government agreement of both countries for the development and operation of two satellites). The program was signed in July 1988 to establish a complete remote sensing system (space and ground segment) to supply both countries with multispectral remotely sensed imagery.
In Nov. 2002, the governments of China and Brazil decided to expand the initial agreement by including another two satellites of the same kind, CBERS-3 and 4, as the second generation of the Sino-Brazilian cooperation effort. The planned cooperative CBERS-3&4 program of CAST and INPE employs enhanced versions of spacecraft and instruments. The... read more

Launch date:
06/12/2014

Gaofen-2 is a follow-on mission of the Gaofen-1technology demonstration mission, a series of high-resolution optical Earth observation satellites of CNSA (China National Space Administration), Beijing, China. GF-2 is part of the CHEOS (China High Resolution Earth Observation System) family.
The mission goal of GF-2 to implement sub-meter level, high geographical accuracy Earth surface imaging, promoting application of CHEOS satellites and its social and economic benefits, meanwhile to make breakthrough in key technologies like fast roll and high stable attitude control, long focal length large f-number,... read more

Launch date:
19/08/2014

SPOT-7 is a high-resolution wide-swath imaging spacecraft built and operated by Airbus Defence and Space taking over the majority of Spot Image after the government support of the SPOT program was terminated. SPOT-6 – launched in 2012 – and SPOT-7 are identical spacecraft, based on the AstroSat-250 satellite bus and use the NAOMI (New AstroSat Optical Modular Instrument) payload to acquire optical imagery to ensure the continuity of SPOT... read more

Launch date:
30/06/2014

Launched in June 2014 with an expected life-time of more than 7 years, Deimos-2 is an agile, high resolution satellite that became the only European fully-private satellite capable of providing sub-metric multispectral imagery. From a 620-km ascending sun-sync orbit, it has a 12/24-km swath (depending on the imaging mode), stereo-par capability and ±45º off-nadir tilting capacity. Its multispectral camera has a panchromatic... read more

Launch date:
19/06/2014

ALOS-2 (Advanced Land Observation Satellite 2) is the follow-on JAXA L-SAR satellite mission of ALOS (Daichi) approved by the Japanese government in late 2008. The overall objective is to provide data continuity to be used for cartography, regional observation, disaster monitoring, and environmental monitoring.
The post-ALOS program of JAXA has the goal to continue the ALOS... read more

Launch date:
24/05/2014

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... read more

Launch date:
03/04/2014

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... read more

Launch date:
23/09/2013

Pages

Hazard group

Terms in the same hazard group

Zircon - This is a contributing Drupal Theme
Design by WeebPal.