Inventory of Glaciers, Glacial Lakes and Glacial Lake Outburst Floods: Monitoring and Early Warning Systems in the Hindu Kush-Himalayan Region - Nepal

Abstract

The glaciers of the Hindu Kush-Himalayas (HKH) are nature's renewable storehouse of fresh water. They serve as the perennial sources of rivers that are used as renewable sources for irrigation, drinking water, energy, and industry. However, these glaciers are retreating; the resultant long-term loss of natural fresh water storage will have as yet uncalculated effects. More immediately, as they retreat, glacial lakes can form behind the exposed and unstable terminal moraines. Sudden breaching of these can result in the discharge of huge amounts of water and debris -- a glacial lake outburst flood or GLOF -- often with catastrophic effects downstream.There is still no detailed inventory of glaciers and glacial lakes, of GLOF events or of potential GLOF sites, in the HKH region. These two publications are designed to start filling this gap. Supported by the United Nations Environment Programme Regional Resource Centre for Asia and the Pacific (UNEP/RRC-AP), ICIMOD has used its expertise in the area of geographic information systems (GIS) to create a comprehensive inventory and GIS database of glaciers and glacial lakes in Nepal and Bhutan using available maps, satellite images, aerial photographs, reports, and field data on different scales. In Nepal, 3,252 glaciers were identified and 2,323 glacial lakes, of which 20 were considered potentially dangerous. In Bhutan, 677 glaciers were identified and 2,674 glacial lakes, of which 24 were considered potentially dangerous.These results will provide the basis for the planning and prioritisation of disaster mitigation efforts as well as a guide for infrastructure planning. They will help scientists, planners, and decision-makers in many areas, particularly water resources and land-use planning. The publications include a description of the methods used to identify glaciers, glacial lakes, and glacial lakes that may pose a threat; as well as an inventory (and maps) of the glaciers and glacial lakes in each country. The database and analysis are the first to cover the whole of the countries on a large scale.