The global climatic change during the first half of the twentieth century has brought a tremendous impact on the high mountainous glacial environment. Many of the big glaciers melted rapidly and gave birth to the origin of a large number of glacier lakes. Due to the faster rate of ice and snow melting, possibly caused by the global warming, the accumulation of water in these lakes has been increasing rapidly and resulting sudden discharge of large volumes of water and debris and causing flooding in the downstream. Glacial lake outburst flood (GLOF) causes disasters to life and property along the downstream, results serious death tolls and destruction of valuable forests, farms and costly mountain infrastructure.

In South Asia, particularly in the Himalayan region, it has been observed that the frequency of the occurrence of GLOF events has been increasing in the second half of the twentieth century. The recent catastrophic GLOF event in the Nepal Himalaya known as the Dig Tsho GLOF in 1985, has destroyed the Namche small hydel project that was built at the cost of US$ 1.5 million approximately. Accurate and timely information on the spatial locations and regular monitoring of the glacier lakes' behavior is needed, to prevent and monitor the GLOF hazards and assess the damages to be occurred in the near future. Modern information tools such as Remote Sensing and GIS could play a lead role in identifying potential risk lakes and monitoring the GLOF events in near real time.

UNEP through its facilities at Environment Assessment Program for Asia-Pacific (EAP.AP), Asian Institute of Technology, Bangkok, is trying to establish an operational early warning system to monitor GLOF hazards in the Hindu Kush Himalayan region. EAP.AP will implement the project in collaboration with the International Center for Integrated Mountain Development (ICIMOD), Nepal. The project will implement the UNEP contribution to the establishment of an operational early warning system to mitigate natural hazards like forest fire, drought and glacier lake outburst flood. Besides, the project will help in assessing the environmental condition of the high mountainous regions. The expected outputs of the proposed study are (i) an inventory of existing glacier lakes along the Hindu Kush Himalaya; (ii) monitoring of potential risk lakes for draining; and (iii) an operational early warning mechanism for GLOF hazards.