Deslizamiento de tierra

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).

UN-SPIDER Regional Support Offices with hazard-specific expertise

Related content on the Knowledge Portal

  • The Disasters programme unit at the National Aeronautics and Space Administration (NASA) recently joined a newly launched online platform aimed at placing anticipatory action on the humanitarian agenda. NASA’s involvement in the Anticipation Hub and the subsequent incorporation of Earth observation (EO) tools, serves to improve the capabilities of anticipatory action globally and demonstrates the potential of utilizing satellite-driven data for anticipatory action in disaster management.

    Anticipatory action in the humanitarian context describes disaster mitigation activities based on in-depth forecast information and risk analysis. This approach has gained traction amongst the humanitarian community in recent years as it is viewed as a more efficient and affordable alternative to...

    read more
    02/02/2021
  • A knowledge platform for adaptation action on climate change recently updated the information, layout and logo of their website. With this step, adaptationcommunity.net aims to improve the user experience of the online platform and consequently facilitate the access to a wide variety of resources on climate change adaptation action, including tools working with Earth observation data.

    Adaptation action in the context of climate change refers to “adjustments in ecological, social, or economic systems in response to actual or expected climatic stimuli and their effects or impacts. It refers to changes in processes, practices, and structures to moderate potential damages or to benefit from...

    read more
    12/02/2021
  • A new report outlines the impact of Global Human Settlement Layer (GHSL) data on various policy areas. The 2020 edition of the “Atlas of the Human Planet”, recently published and launched virtually by the Joint Research Centre (JRC) of the European Commission as a deliverable to the Group on Earth Observations (GEO) Human Planet Initiative, explores the impact of GHSL data on various policy areas, including disaster risk management.

    GHSL data refers to “global spatial information, evidence-based analytics and knowledge describing the human presence on the planet”. This data relies on spatial information from Landsat 8, Sentinel-1 and Sentinel-2. It is mainly cost-free and...

    read more
    18/02/2021
  • The use of multi-risk information systems is crucial in confronting the increasing risks posed by natural hazards. In some cases, risk is increasing due to inadequate land-use norms or regulations that allow for the construction of infrastructure in areas exposed to such natural hazards. In other cases, vulnerability increases due to lack of awareness or extreme poverty.  The need to address risks from the point of view of multiple hazards is necessary to contribute to sustainable development and has been incorporated as an essential element of the Sendai Framework for Disaster Risk Reduction 2015-2030.  For this purpose, the RIESGOS 2.0 project was launched in March 2021. Under the coordination of the German Aerospace Center (DLR), the project builds on the accomplishments of its predecessor - RIESGOS - as a multi-risk information system that models and simulates natural hazards to support disaster...

    read more
    17/03/2021
  • A new report by the world’s largest humanitarian aid network highlights global disasters, populations most vulnerable to them and the efforts of local institutions in preventing, preparing for and responding to them. The 2020 edition of the World Disasters Report, “Come Heat or High Water”, was launched virtually from the offices of the International Federation of Red Cross and Red Crescent Societies (IFRC) in Vienna on November 16. This year’s report discusses climate- and weather-related disasters and their humanitarian impact. It argues for the usefulness of smart financing and space-based information in disaster management support.

    The report warns that the global effort to address climate change is leaving behind...

    read more
    19/11/2020
  • The hurricane season in Central America normally quiets down at the end of October, but this year is one of those rare years when tropical storms and hurricanes in the region have occured beyond the typical season. With 30 events thus far, the 2020 tropical storm season in the Caribbean continues to take its toll in developing countries in Central America. Hurricane Eta entered the west coast of Nicaragua on 3 November as a Category 4 hurricane – the second-highest classification category. It triggered massive floods in Nicaragua, Honduras and Guatemala. In some regions, the magnitude of these floods was similar to those triggered by Hurricane Mitch in 1998, which devastated the region and killed more than 35,000 people throughout Central America. Fortunately, the consequences of Hurricane Eta were much smaller.

    UN-SPIDER has been supporting disaster response efforts to Hurricane Eta at the request of the...

    read more
    16/11/2020
  • The University of Alaska Fairbanks has launched a MOOC about Synthetic Aperture Radar (SAR) remote sensing for disaster monitoring. SAR is a remote sensing technology that can see the ground even during darkness and through rain, clouds, or smoke. Participants of the course will gain an intuitive understanding of the information contained in SAR observations and learn to use a range of analysis techniques to apply SAR data to disaster mapping and management. Specific topics will include:

    • The mathematical and physical principles of SAR remote sensing
    • How to access and visualize SAR data
    • Interpretation of SAR images in the context of disaster monitoring
    • Interferometric SAR (InSAR) concepts
    • Flood mapping and SAR change detection for hazard analysis
    • InSAR-based analysis of volcanoes and landslides

    The learned concepts will be put into practice in simulated disaster response exercises, in which participants will analyze SAR...

    read more
  • In order to discuss and promote the use of space technologies in addressing natural hazards such as forest fires and landslides in Latin America, UN-SPIDER conducted a virtual regional expert meeting on the topic of “Space-based Solutions for Disaster Risk Reduction and Emergency Response in Latin America” from 22 to 24 September 2020. The meeting was jointly organized with UN-SPIDER Regional Support Offices from Argentina (National Space Activities Commission, CONAE), Brazil (Federal University of Santa Maria, UFSM), Colombia (Geographic Institute Agustin Condazzi, IGAC), and Mexico (Mexican Space Agency, AEM).

    In Latin America, UN-SPIDER and its Regional Support Offices have regularly carried out regional expert meetings, training courses and other joint efforts since 2011. The last Regional Expert Meeting took place in 2017 in Mexico.

    The meeting, which consisted of three two-hour-long sessions, brought together a total of over 200 disaster management stakeholders...

    read more
    28/09/2020
  • En décadas recientes muchas comunidades en América Latina y el Caribe han experimentado desastres ocasionados por inundaciones, sequías, deslizamientos, terremotos, erupciones volcánicas y maremotos o tsunamis que han erosionado los logros asociados a procesos de desarrollo. Además, en este año 2020 la pandemia ocasionada por el virus COVID-19 ha impactado a muchos países del mundo, forzando a los gobiernos, al sector privado, a la sociedad civil y a organismos regionales e internacionales a modificar sus planes de trabajo. De manera paralela, varios países del Este de África, del Sudoeste de Asia y de América Latina están experimentando los impactos de la plaga de langosta.  

    Convencidos que las tecnologías espaciales pueden jugar un papel preponderante en apoyar los esfuerzos que llevan a cabo las instituciones en materia de gestión para la reducción de riesgos, la preparación, la respuesta y la recuperación en caso de desastres; la Asamblea General de las...

    read more

Term Parents

UN-SPIDER Regional Support Offices with hazard-specific expertise