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 on the Knowledge Portal

Event

Sentinel-2 is the high-resolution optical satellite of ESA and the EU. The images have a resolution of 10 to 20 meters, higher than Landsat, and, as always with the Copernicus programme, the data are free and open.
In this tutorial, we’ll download an image, make it look good, and create maps of vegetation indices to show the general health of crops and other vegetation. This is a basic tutorial, but... read more

Remote Sensing of Drought

Prolonged drought can result in economic, environmental, and health-related impacts. In this webinar, participants will learn how to monitor drought conditions and assess impacts on the ecosystem using precipitation, soil moisture, and vegetation data. The training will provide an overview of drought classification, as well as an introduction to web-based tools for drought monitoring and visualization. Lectures will be followed by hands-on demonstrations of data access and visualization.

Learning Objectives: 

By the end of... read more

Data Source

Publishing institution: Canadian Space Agency (CSA)
Screenshot of Global Soil Erosion (ESDAC)
Publishing institution: Joint Research Center, European Commission (JRC)
The European Soil Data Centre (ESDAC) has provided a map with soil assessments from the years 2001 and 2012.
Screenshot of Zansea
Publishing institution: Tanzania Commission for Science and Technology (COSTECH)
The Tanzania Commission for Science and Technology (COSTECH), in partnership with the Revolutionary Government of Zanzibar (RGoZ), has launched an initiative to produce detailed aerial imagery maps of the islands of Zanzibar. The cooperative project is called the Zanzibar Mapping Initiative (ZMI). This initiative has drawn global attention because the mapping is done entirely with drones; the ability to map is now available widespread at a local level. The maps produced are of exceptional spatial resolution. Additionally, their free and open source data sets includes a comprehensive compilation of available vector and raster data covering the whole of Tanzania. Users can find not only aerial imagery produced from drones, but everything from census data to land use layers. More information can be found on the ZMI project website: http://www.zanzibarmapping.com/

GP-STAR factsheet

Schematic Workflow for the derivation of an exemplary Sendai indicator using crisis information generated from satellite remote sensing (Source: own figure; Copernicus Emergency Management Service (©European Union), EMSN024, EMSN056)
Publishing institution: German Federal Office of Civil Protection and Disaster Assistance

To meet the global challenges, the United Nations adopted several framework agreements, including the Sendai Framework for Disaster Risk Reduction at the Third United Nations World Conference on Disaster Risk Reduction (2015-2030). The framework builds the international reference point for disaster... read more

News

As part of the technical advisory support it provides to countries worldwide in making use of space-based information for disaster management, UN-SPIDER carries out an Institutional Strengthening Mission to Ecuador from 8 to 12 April 2019 upon the request of the Government of Ecuador. This activity is jointly organized by the United Nations Office for Outer Space Affairs (UNOOSA), through its United Nations Platform for Space-based Information for Disaster Management and Emergency... read more

Publishing date: 08/04/2019
This image captured by the Copernicus Sentinel-2A satellite on 28 December 2015. It demonstrates Nepal’s varied terrain from the mountains to the north (left side) to the plains in the south (right side). Vegetation appears red in this false-colour image, while waterways and buildings appear light green and blue. Image: ESA.

On 12 March, Nepal Telecommunications Authority (NTA) signed an agreement with French satellite operator Thales Alenia Space to build Nepal’s first communications satellite. The Nepalese government intends to use the satellite to provide nationwide internet access to its citizens, improve disaster management efforts and strengthen economic growth in the country.

The development of Nepal’s own satellite system proves to be significant in terms of improving the country’s... read more

Publishing date: 29/03/2019

Advisory Support

As part of the technical advisory support it provides to countries worldwide, UN-SPIDER carried out an Institutional Strengthening Mission to Republic of Ecuador from 8-12 April 2019 upon the request of the government. This activity was jointly organized by the United Nations Office for Outer Space Affairs (UNOOSA), through its United Nations Platform for space-based information for disaster management and emergency response (UN-SPIDER) and the National Risk and Emergency Management Service of Ecuador. The Military Geographic Institute of Ecuador, the Agustín Codazzi Geographic Institute of Colombia (IGAC) and the Federal University of Santa Maria, Rio Grande do Sul, Brazil supported the mission.

Mission dates: 08/04/2019 to 12/04/2019

Pages

Hazard group

Terms in the same hazard group

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