INTRODUCTION
 
The Tibet Autonomous Region of the Peoples’ Republic of China is a mountainous region, occupied mostly by mountains and hills. The accumulation of water flows mainly from the mountain cause intensive erosion and drastic destruction. The floods always occur in the valleys of the mountainous region. Based on its source, floods can be divided into three types: plateau-rainstorm mountain flood, melted-snow mountain flood, and melted-glacier mountain flood. The glaciers, some of which consist of huge amounts of perpetual snow and ice, are found to create many glacial lakes. These glaciers as well as glacial lakes are the sources of the headwaters of many great rivers in the region. Most of these lakes are located in the down valleys close to the glaciers. They are formed by the accumulation of vast amounts of water from the melting of snow and ice cover and by blockage of end moraines. The sudden break of a moraine may generate the discharge of large volumes of water and debris causing floods.

Since the second half of the 20th century, several glacial lakes have developed in the Hindu Kush-Himalayan (HKH) region. This may be attributed to the effect of recent global warming. The glacial lakes are formed on the glacier terminus due to the recent retreating processes of glaciers. The majority of these glacial lakes are dammed by unstable moraines, which are formed by glaciations during the Little Ice Age.

Occasionally, a lake outbursts releasing an enormous amount of stored water, which causes serious floods downstream along the river channel. This phenomenon, generally known as glacial lake outburst floods (GLOFs), is recognized as a common problem in HKH countries of China (Tibet), Nepal, India, Pakistan, and Bhutan.

According to the World Glacier Inventory (WGI), China carried out glacier inventory throughout the country from 1979. This work was completed in 2002 and documented 21 books. This glacier inventory took into consideration with limited extent of glacial lakes, but did not undertake a systematic inventory. A China-Nepal joint team carried out fieldwork in the Pumqu and Poiqu River basins and inventoried glaciers and glacial lakes in 1980s. They carried out research on the outburst of glacial lakes and published a book entitled “Report on the First Expedition to Glaciers and Glacier lakes in the Pumqu (Arun) and Poiqu (Bhote-Sun Koshi) River basins, Xizang (Tibet), China”.

The change of glaciers in the Himalaya-China region, influenced by the global change of climate, is marked and distributed asymmetrically in different areas. A second inventory of glaciers and glacial lakes could statistically detect the change and analyze the activity of glaciers. The study of satellite images indicates the presence of glaciers and glacial lakes and occurrences of GLOFs in the Himalayas. The impact on downstream of GLOFs is reported to be highly destructive in nature and lead to long-term secondary environmental degradation in the valleys, both physically and socio-economically.

Cold and Arid Regions’ Environmental and Engineering Research Institute of the Chinese Academy of Science and the Bureau of Hydrology Tibet of Tibet Water Conservancy and Hydrology Bureau of China in collaboration with ICIMOD undertook the project entitled “Inventory of Glaciers and Glacial Lakes and Glacial Lake Outburst Floods’ Monitoring and Early Warning Systems in the Hindu Kush-Himalayan Region” from June 2002.

For mapping and compiling of the inventory of glaciers and glacial lakes, the methodology is used similar to Nepal and Bhutan (Mool et al. 2001a and Mool et al. 2001b), which is based on the research of the Temporary Technical Secretary (TTS) for the World Glacier Inventory (WGI) of the Swiss Federal Institute of Technology (ETH), Zurich (Muller et al. 1977 and the World Glacier Monitoring Service [WGMS] 1989).

OBJECTIVES

  • To understand the GLOF phenomenon by creating an inventory of existing glacial lakes and monitoring the GLOF events on a regular basis
  • To establish an effective early warning mechanism to monitor GLOF hazards using remote sensing (RS) and geographic information systems (GIS) in the Hindu Kush-Himalayan region
  • To build the capabilities of national institutions to assess and monitor the GLOF
    phenomenon
  • To disseminate the results and outputs among relevant organizations in the region that could make use of this information for GLOF hazard prevention and mitigation planning

OUTPUTS

  • An inventory of glaciers and glacial lakes of Pumqu, Poiqu, Rongxer, Jilongcangbu, Zangbuqin, Daoliqu, Jiazhagangge, Majiacangbu.
  • Identification of potential risk lakes
  • Recommendations for the establishment of a system for monitoring potential risk lakes using RS and GIS
  • Strengthened capabilities of the national institutions to implement an early warning system for GLOF hazard monitoring
  • Informed relevant institutions regarding the results and potential risks, thereby increasing the capability to plan for and prevent or mitigate the risks
  • Dissemination of the results and outputs to relevant institutions

ACTIVITIES

  • Glacier and glacial lake inventory
    • Acquisition of the Landsat-5 TM image of 1990 and Landsat-7 ETM+ images of 2000, both covering the research region
    • Collecting GIS data layers including Digital Elevation Models (DEM) with resolution 28.5m from GLOF project
    • Obtaining the spatial and attribute information of glaciers and glacial lakes
    • Data analysis and report writing
  • Monitoring potential risk lakes
    • Acquisition of Landsat-5 TM image of 1990 and Landsat-7 ETM+ images of 2000, both covering the research region for glacial lakes
    • Collection of inventory data of glacier and glacial lake from Report on First Expedition to Glaciers and Glacier Lakes in The Pumqu (Arun) and Poiqu (Bhote-Sun Koshi) River basins, Xizang (Tibet), China and Glacier Inventory of China——The Ganga Drainage basin(XI), Indus River Drainage Basin(X).
    • Collection of Meteorological data like temperature, rainfall and evaporation.
    • Field checking and validation of results
    • Report writing
  • Establishment of an early warning system

- Developing the methodology using RS and GIS techniques for the inventory of glaciers and glacial lakes and for the GLOF monitoring and early warning system

  • Results dissemination/publication
  • Publication of a comprehensive report including (1) to (3) above
  • Dissemination of results and outputs in the form of reports, on CD, and through the Internet
  • Organization of a workshop to release the results and outputs
  • FLOW CHART