Landslide

In the early hours of August 2, 2014, nearly 2 kilometers of hillside collapsed in rugged northern Nepal. Image: NASA.

Definition

The term “landslide” refers to a variety of processes that result in the downward and outward movement of slope-forming materials, including rock, soil, artificial fill, or a combination of these. The materials may move by falling, toppling, sliding, spreading, or flowing (UNDRR).

A landslide is a downslope movement of rock or soil, or both, occurring on the surface of rupture, either curved (rotational slide) or planar (translational slide) rupture, in which much of the material often moves as a coherent or semi coherent mass with little internal deformation (USGS).

Facts and figures

According to the International Disaster Database of the Centre for Research on the Epidemiology of Disasters, in the period from 2000 to 2014, 26,000 persons have lost their lives because of landslides and flash floods while the economic losses amounted to over US$ 40 billion (OFDA/CRED).

Landslides can be classified into different types on the basis of the type of movement and the type of material involved. In brief, material in a landslide mass is either rock or soil (or both); the latter is described as earth if mainly composed of sand-sized or finer particles and debris if composed of coarse fragments. The type of movement describes the actual internal mechanics of how the landslide mass is displaced: fall, topple, slide, spread, or flow. Thus, landslides are described using two terms that refer respectively to material and movement, that is rockfall, debris flow, and so forth. Landslides may also form a complex failure encompassing more than one type of movement that is, rock slide and debris flow (USGS).

The primary driving factor of landslides is gravity acting on a portion of a slope that is out of equilibrium. The following are some of the major landslide triggering mechanisms:

  • River erosions, glaciers, or ocean waves
  • Weakening of rock and soil slope properties through water saturation by snowmelt or heavy rains
  • Stresses, strains and excess of pore pressures induced by the inertial forces during an earthquake (earthquakes of magnitude greater than or equal to 4.0 can trigger landslides)
  • Volcanic eruptions with the production of loose ash deposits that may become debris flows (known as lahars) during heavy rains
  • Stockpiling of rock or ore, from waste piles, or from man-made structures
  • Changes of the natural topography caused by human activity (UNDRR).

Related content

Data Source

Publishing institution: Joint Research Center, European Commission (JRC)
GIS Malawi is a webmapper which provides various vector and raster layers covering a broad range of topics including natural hazards.
Publishing institution: National Aeronautics and Space Administration (NASA)
The Cooperation Open Online Landslide Repository (COOLR) is an open platform where landslide reports can be shared and accessed in order to increase awareness as well as to improve scientific modelling and emergency response to landslides. The data includes citizen science landslide reports, Global Landslide Catalog data, and other landslide catalog data. It is visualized in the Landslide Viewer from where the data can be accessed, computed and exported.
Publishing institution: Norwegian Geotechnical Institute (NGI)
The Global Landslide Hazard Distribution is a tool developed by the Norwegian Geotechnical Institutes (NGI) which maps the global landslide and snow avalanche hazards. In doing so, the model incorporates slope, soil moisture conditions, precipitation, seismicity and temperature data.
Publishing institution: Canadian Space Agency (CSA)

Advisory Support

Upon the request of the Ministry of Territorial Administration (MINAT), Government of Cameroon, UN-SPIDER carried out a week-long Institutional Strengthening Mission (ISM) to Yaoundé from 15 to 19 July. The mission aimed to strengthen the capacities of the Department of Civil Protection (DPC) of Cameroon in using space-based information in all phases of the disaster management cycle. It was the third UN-SPIDER mission to Cameroon after a Technical Advisory Mission (TAM) in 2011 and an Institutional Strengthening Mission (ISM) in 2012, the latter including a training course on “Remote Sensing for Disaster Management”.

Mission dates: 15/07/2019 to 19/07/2019

As part of the technical advisory support it provides to countries worldwide, UN-SPIDER carried out an Institutional Strengthening Mission to Nepal from 17 to 21 December 2018 upon the request of the government. The mission was a follow-up activity to the Technical Advisory Mission (TAM) to Nepal in July 2017 that assessed use of space-derived information in all aspects of disaster management and offered recommendations and action plan to strengthen the disaster risk management and emergency response in the country. The TAM and ISM were conducted with support from the Ministry of Home Affairs (MoHA). The Nepal GIS Society also offered support in organizing the programme.

Mission dates: 17/12/2018 to 21/12/2018

News

This map shows the ground motion during the six months following the earthquake that struck the Indonesian Island of Sulawesi on 28 September 2018, and was obtained by processing Copernicus Sentinel-1 images acquired between October 2018 and April 2019. Image: ESA/contains Copernicus Sentinel data (2018–19), processed by Planetek Rheticus Service.

In September 2018, the Indonesian island of Sulawesi was hit by a 7.5 magnitude earthquake. The impact, combined with the tsunami, landslides, and soil liquefaction that followed, “... claimed well over 2000 lives, destroyed homes, buildings, infrastructure and farmland in several districts,” according to the European Space Agency (ESA)

Ten months later, response efforts are now moving into the... read more

Publishing date: 06/08/2019
Mission team with the director and staff of the Department of Civil Protection and other organizations. Image: DPC.

Upon the request of the Ministry of Territorial Administration (MINAT), Government of Cameroon, UN-SPIDER carried out a week-long Institutional Strengthening Mission (ISM) to Yaoundé from 15 to 19 July. The mission aimed to strengthen the capacities of the Department of Civil Protection (DPC) of Cameroon in using space-based information in all phases of the disaster management cycle. It was the third UN-SPIDER mission to Cameroon after a Technical Advisory Mission (TAM) in 2011 and an Institutional Strengthening Mission (ISM) in 2012, the latter including a training course on “... read more

Publishing date: 22/07/2019
Regional Support Offices mentioned:

Event

The International Consortium on Landslides (ICL) and the ISDR-ICL Sendai Partnerships 2015-2025 announce the  5th World Landslide Forum (WLF5) to be held November 2-6, 2020, in Kyoto Japan. 

This Forum will include a mid-term review of the ISDR-ICL Sendai Partnerships, voluntary contribution to the Sendai Framework 2015-2030 and the Agenda 2030 – Sustainable Development Goals, especially Goal 11 "Make cities and human settlements inclusive, safe, resilient and sustainable".

Participants of the Fourth World Landslide Forum adopted the 2017 Ljubljana... read more

This webinar focuses on Flood History and - Risk as well as on Land Motion (subsidence), but related topics that will be touched upon are LU/LC and Change, Transport Infrastructure and Green Urban areas, as these are also relevant for assessing sustainability of cities with respect to Climate Resilience and... read more

Pages

Hazard group

Terms in the same hazard group

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