Last week’s policy brief, Natural Disaster Risks in Central Asia, based on a UNDP review of available risks assessments, has provided some interesting information on landslides in Central Asia.
Landslides are one of the main natural hazards facing Central Asia. Their triggers vary, but they include the steepness of slopes – which has been continuously increasing due to seismic events, mining, increased torrential rainfall as well as rising water tables and continued degradation.
As shown in the map below, landslide risks differ among Central Asian countries and are most pronounced in the mountainous areas of Tajikistan and Kyrgyzstan. Currently, Tajikistan has around 50,000 landslide sites, of which 1,200 directly affect settlements.
There are a multitude of transbourdary hazards in the Ferghana Valley, which straddles Uzbekistan, Kyrgyzstan and Tajikistan. Here and elsewhere, landslides can trigger other transboundary hazards, such as glacial lake outburst floods and the release of toxic substances into river basins (particularly in the Mayli Suu area of the Ferghana Valley), with the potential to adversely impact a significant number of people.
Scientists in Uzbekistan have been able to establish a strong correlation between landslide activation and four to five year cycles of wet and dry years. The volume of season and annual precipitation, snow and glacial melting and intense precipitation play a critical role in triggering landslides.
Landslide monitoring and research has declined since the fall of the Soviet Union in 1991. Even in countries such as Kazakhstan that have greater resources to devote to hazard analysis, landslide surveys remain underfunded and adequate observation posts are lacking. Thus, the available hazard analysis of landslides in Central Asia is outdated and in need of increased support.
At the same time, according to the available projections of climate change in the region, landslides will become more widespread, owing to the increasing prevalence of extreme rainfall events and more rapid melting of glaciers.
Landslides exist in nature and in many cases cannot be prevented; however their impact and consequences can be mitigated by reducing the vulnerability of people and infrastructure to natural hazards. With the appropriate preventative measures, significant loss of life and economic damage could be avoided.