Geologische Naturgefahren


High mountain hazards

Gravity tends to level out the Earth's surface. High mountain areas therefore show active morphodynamics with frequent mass relocation processes. Most of the time, such processes occur at slow rates or have a limited spatial extent. Though causing some damage when interfering with people or assets, strategies to manage such risks have proved successful in most of the world's mountains.

This - on the broad scale steady - relocation of mass from higher to lower areas ensures a dynamic equilibrium of mountain geosystems. Sometimes, however, this equilibrium is disturbed by forces from outside the system. Some of these forces act for a few minutes only - e.g. earthquakes - others for decades and centuries. Climate change belongs to the latter category. High-mountain geosystems react highly sensitive to climate signals like fluctuations of temperature or precipitation. Many glaciers in the world's mountain areas are in a stage of retreat. The tongues often leave behind an undulating mass of till, still containing some quantity of ice. Such places are favourable for the development of glacial lakes. Some of these lakes are prone to sudden drainage, e.g. by hydrostatic failure or retrogressive erosion of the dam, or by flood waves triggered by falling ice or rocks. Glacial Lake Outburst Floods (GLOFs) may develop into powerful debris flows with long travel distances. Since the glacial lakes are far up in the mountains and events occur at long intervals, the population is often not prepared and the natural processes evolve into disasters.

When trying to analyze glacial hazards, it is necessary to look not only at single glaciers or glacial lakes, but to have a broader view at entire catchments: high-magnitude events often occur as complex process chains involving the glacier (ice avalanche into the lake), the lake itself (flood wave and sudden drainage) and the downstream valley (entrainment and deposition of sediment, backwater effects with subsequent outbursts).

Not all hazards in high mountain areas are attributed to climate change. Short-term disturbances like heavy or extended rainfall - destabilizing the slope systems - or powerful earthquakes may trigger gravitational mass movements of high magnitude. Many cases are evident where the deposits of such movements have dammed lakes. Such lakes are then a hazard by themselves. They may drain suddenly by the failure of the dam or by further mass movements into the lake and cause major destruction downstream.

IAG-BOKU is working on the analysis and assessment of high mountain hazards. Currently, the regional focus is on the Pamir in Tajikistan (Central Asia), other research areas include the Hunza Valley in Pakistan and Southern Chile.

Learn more about the projects of IAG-BOKU in Central Asia

This section provides some basic information and access to the details regarding the projects of IAG-BOKU in Central Asia, with a particular focus on Tajikistan.

Links: General information about Tajikistan (Wikipedia) Selection of photos of Tajikistan Presentation about research of IAG-BOKU in Central Asia

Poverty Alleviation by Mitigation of Integrated high-mountain Risk

Duration: 01/2011 - 12/2013
Funding: European Union
Partners: Hilfswerk Austria International, FOCUS Humanitarian Assistance, MSDSP

The communities in the mountains of Central Asia have to struggle with a variety of problems. One of them are geohazards emanating from earthquakes, extreme meteorological events, and environmental fluctuations in the high mountain areas. The latter include destabilization of debris by melting of glaciers and permafrost and the development of glacial lakes. Content of the project is to have a closer look on such hazards in the border areas Tajikistan/Kyrgyzstan and Tajikistan/Afghanistan and to develop strategies to live with the risks emanating from thes hazards. The work partly builds on the TajHaz project.

Access Background and objectives Research area Methodology Results Team

Download Project layout (pdf)

Remote Geohazards Assessment in Tajikistan

Duration: 04/2009 - 07/2010
Funding: SDC, DFID
Partners: FOCUS Humanitarian Assistance, GTZ, University of Zuich

The mountains of Tajikistan are subjected to glacier fluctuations leading to the development of glacial lakes. Some of the mare hazardous, glacial lake outburst floods have led to major disasters. On the other hand, earthquakes or extreme rainfall may cause landlslides affecting the communities in the valleys. The aim of the project was to identify potentially hazardous situations in selected areas, to develop impact scenarios and to give recommendations how to deal with the hazards and risks.

Access Background and objectives Research area Methodology Results Team