Glacial Lake Mapping and Glacial Lake Outburst Flood (GLOF) Risk Assessment in the Hindu Kush-Himalayas

It is generally accepted that many glaciers throughout the world, including in the Hindu Kush-Himalayan (HKH) region are thinning, and their termini retreating, as a result of climate warming. The thinning and retreat of glaciers in the HKH region has been accompanied by formation of melt-water lakes, both on the glacier surface and between the terminus and the exposed end mraine. The glacial lakes on the surface at the terminus end and behind the end moraine are of special interest. These kinds of lakes are held back (dammed) by more or less unstable moraine complexes, and can have a potential to breach their moraine dams and cause serious floods and debris flows downstream. This phenomenon known as a glacial lake outburst flood (or GLOF) has the potential for generating extensive destruction in the valley downstream. The impact of such an outburst depends on the physical character of the dam, the lake size and depth and the rapidity of its drainage, and the nearby surroundings.

One of the main tasks for ICIMOD is to undertake a regional mapping of glacial lakes and assessment of the increasing risk from GLOFs. This task builds upon ICIMOD’s past experience in the technical and physical aspects of mapping of glaciers and glacial lakes in the HKH countries since 1999. Around 200 glacial lakes have been identified as potentially critical in the region, but the real risk of these lakes bursting their dams remains largely unknown and needs to be researched. ICIMOD is carrying out mapping and risk assessment in collaboration with national partners in the region.

Activities

Activity 1

Too much water, too little water - adaptation strategies to climate-induced water stress and hazards in the greater Himalayan region.

Geographical Coverage

HKH region

Duration

2008 – 2010 (3 years)

Core Financial Partners

Swedish International Development Cooperation Agency (Sida)

One of the primary aims of this project is to strengthen capacity within ICIMOD and national partners for undertaking regular monitoring of glaciers, snow and ice fields, and pro-glacial lakes and undertake risk and vulnerability assessment of communities and infrastructure in the downstream vicinity of glaciers and GLOF lakes. This, in turn, should provide decision makers in the region (and beyond) with timely and adequate data and information on the status of these features.

One of the important activities under the project is the development of a new inventory of glacial lakes for the entire Hindu Kush-Himalaya. It will be performed by ICIMOD in partnership with national institutions in the regional member countries such as the Cold and Arid Regional Environmental and Engineering Research Institute (CAREERI)/Chinese Academy of Sciences. This will provide an up-to-date regional inventory for the entire region.

The inventory is being prepared to ensure improved understanding of the characteristics of glacial lakes and the mechanism of GLOFs. Efforts will be made to determine the status of glacial lakes, their changing patterns, expansion and outburst mechanisms, and the impact of climate change on them. The capabilities of the national institutions will also be strengthened. Finally, inter-country cooperation throughout the HKH region will be augmented by creation of a ‘regional glacial lake information system’.

Activity 2

Hazard assessment and mitigation study of potential glacial lake outburst floods (GLOFs) in Nepal

Geographical Coverage

Nepal

Duration

2009-2010 (fifteen months)

Core Financial Partners

The World Bank.

The objectives of the project are

  1. to develop recommendations for adaptation and mitigation against GLOF hazards in Nepal; and
  2. to assist Nepal in the development of an overall strategy to address the risk from GLOFs in the future.

The project aims to assess GLOF hazards from potentially dangerous lakes in Nepal and to investigate vulnerable downstream areas. The intent is also to strengthen partnerships among key stakeholders for development of a risk reduction strategy. ICIMOD is collaborating with government and non-government organisations as well as academic institutions. Three lakes in Nepal, namely Imja, Dudhkoshi basin, Thulagi (Dona), Marsyangdi basin, and Tsho Rolpa, Tama Koshi basin were identified as project implementation sites.

Contact Information

Pradeep Mool
Integrated Water and Hazard Management
pmool@icimod.org