Between 2004 and 2010, 2,620 landslides killed a total of 32,322 people worldwide – a figure which doesn’t even include those caused by earthquakes. A new map from the NASA Goddard Space Flight Center is helping display where landslides are most likely to occur around the world, and therefore how future death tolls can be reduced.
Thomas Stanley and Dalia B Kirschbaum compiled the Global Landslide Model which tracks recent rainfall and, after checking recorded information about the susceptibility of terrain in each area, determines the likelihood of landslides occurring. This information includes such criteria as whether or not roads have been built, whether trees have been cut down, whether a major tectonic fault is nearby, the state of the local bedrock, and – the most important factor – the steepness of hillsides.
Map of worldwide landslide susceptibility using data by Thomas Stanley and Dalia Kirschbaum (NASA/GSFC) and from the Shuttle Radar Topography Mission (SRTM) (Image: NASA Earth Observatory/Jesse Allen)
As might be expected, the most susceptible parts of the planet for landslides are regions of high altitude, including the Alps, the Andes, and the Himalayas. However, there remain significant geographical disparities regarding the susceptibility of different countries and continents to fatal landslides. For example, as NASA points out, even though a quarter of the 5,741 landslides reported between 2007 and 2013 occurred in North America, less than one per cent of reported fatalities occur there.
The lack of quality infrastructure and the impact of mass deforestation in Africa is also especially noticeable, given that the continent saw seven per cent of recorded landslide-related deaths occur during this time period (a figure which could easily be far below the true number, due to a lack of overarching recording systems) from far fewer recorded landslides than in North America.
Map of African and Mediterranean landslide susceptibility using data by Thomas Stanley and Dalia Kirschbaum (NASA/GSFC) and from the Shuttle Radar Topography Mission (SRTM) (Image: NASA Earth Observatory/Jesse Allen)
‘This disparity tells us that there is much that could be done in many areas to understand and respond to threats from landslides more effectively,’ says Kirschbaum. Mountainous landscapes such as the Ethiopian Highlands, the Cameroonian Ridge, the Great Rift Valley, the Central Highlands in Madagascar, and the Drakensberg mountain range in South Africa, are all highlighted as being especially susceptible places for deadly landslides.