The HKH region is one of the most dynamic, fragile, and complex mountain systems in the world as a result of tectonic activity and the rich diversity of climates, hydrology, and ecology. The high Himalayan region is the freshwater tower of South Asia and has the highest concentration of snow and glaciers outside the polar regions giving it the name Third Pole.

Balati glacier, Pithoragarh district, Uttarakhand (Source: Uttarakhand and I)

Meltwater from the snow and glaciers feeds the ten largest river systems in Asia, which together support some 1.3 billion people in their downstream basin areas. These mountain ranges not only present a beautiful landscape, but they also play an important role in global atmospheric circulation, the hydrological cycle, and water resources availability, and provide a wide range of ecosystem services.

Mountain areas are particularly vulnerable to climate change, and the HKH region is no exception. A number of noticeable impacts related to climate change have already been documented. The glaciers in much of the region show signs of shrinking, thinning, and retreating. Among others, this is leading to the formation and expansion of glacial lakes, which could lead to an increase in the number of glacial lake outburst floods. If the present trends persist, the store of glacier ice will gradually be reduced, which will impact on the availability of water resources.

Notwithstanding the importance of the HKH region, there is a lack of data on the snow and glacial resources of these mountains, and especially of the long-term information on glaciers required for a credible scientific assessment. Glacier inventories have been compiled for some parts of the region using different approaches, but there has been no comprehensive coordinated assessment. A long-term consistent glacier database is needed to support assessments of glacier status across the region and understanding of climate change impacts on glaciers, as well as for climate and hydrological monitoring.

The study presented here was designed to develop comprehensive baseline information on the glaciers of the entire HKH region organised by major basins and sub-basins. The glacier inventory was prepared from satellite images taken within a short period to maintain uniformity of the observational database, and for areas in all countries except China was prepared at ICIMOD. The inventory data for basin areas in China were received through collaboration with CAREERI.

In addition to the immediate research objectives, the long-term objective was to support global climate change research by facilitating access to well-documented glacier data. The project also aimed to build the regional capacity of partner institutes engaged in glacier mapping and to undertake the glacier inventory using tools and methods developed at the local and national level.

The glacier database will be provided online to facilitate access to information by policy and decision makers, scientists, and the public at large in the region and beyond. The database provides a basis for assessing the rates of change of glaciers, which is important for understanding climate change, water resource planning, and mitigation of glacial lake outburst flood (GLOF) hazards.

The report is divided into the following sections:

Part 1 – Methodology

• Introduction
• The Glacier Inventory Approach
• Data Collection and Glacier Mapping Methodology
• Glacier Inventory Attributes

Part 2 – Status of Glaciers

• Amu Darya Basin
• Indus Basin
• Ganges (Ganga) Basin
• Brahmaputra Basin
• Irrawaddy Basin
• Salween Basin
• Mekong Basin
• Yangtze Basin
• Yellow River Basin
• Tarim Interior Basin
• Eastern Asian Qinghai-Tibetan Interior Basins

A copy of the entire report can be accessed at this link