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

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