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Remote Sensing Technology Center of Japan



RESTEC Activities related to the Observation of Glaciers and Glacial Lakes in Alpine Areas


By Nobuhiro Tomiyama, Vice Senior Researcher, Research and Development Division

Research conducted by RESTEC on alpine glaciers and glacial lakes began in about 2000. At the time there was concern about the potential bursting and flooding of Lake Tsho Rolpa, the largest glacial lake in the Himalayas, in Nepal. After some time had passed, at the Asia Pacific Regional Space Agency Forum (APRSAF) held in January 2004, Japan received a request from Nepal for cooperation in relation to the establishment of an early-warning system concerning the potential bursting of Himalayan glacial lakes. Unfortunately, Japan did not have the opportunity to respond to this request. However, this event did lead to the reconfirmation of the importance of monitoring the potential bursting of glacial lakes, and moreover, it was a trigger that led to RESTEC’s involvement in ongoing research into alpine glaciers and glacial lakes, including on-site surveys.

In the light of the above, in 2005 “Research on Methods of Monitoring Glacial Lakes in the Himalayan Region” was selected as a recipient of a grant from the Watanabe Memorial Foundation for the Advancement of Technology. At the time when candidates for the grant were being sought, we had planned to conduct a survey in Nepal. However, because of the onset of an uncertain political situation in Nepal, the region to be subject to a survey was changed from Nepal to the Himalayan region of neighboring Bhutan, a country famous for its smiles. In the research, DSM data* from ALOS/PRISM, launched at the same time, were used and, by combining these data with the results of the on-site survey, researchers were able to estimate the areas along river banks that would be damaged in the event of a glacial lake outburst flood. These results were announced at the 37th COSPAR Scientific Assembly in 2008.

The next activity RESTEC was involved in, under commission by the World Bank in 2007, was also a major project, the “Technical Assistance and Capacity Building on Satellite-Based Monitoring of Ground Cover in Andean Glacier Regions for CCIG Adaptation to Rapid Glacier Retreat in the Tropical Andes Project.” In this undertaking, in addition to conducting training of glacier researchers from Peru, Bolivia, Ecuador, and Columbia in regard to the technical transfer of methods of analysis utilizing ALOS data, RESTEC also provided support through the provision of ALOS data as well as technical advice in relation to the analysis, on the basis of agreements of approximately three years’ length, in order that continuous research could be implemented. In previous research on the Himalayan glaciers that RESTEC was involved in, the main focus was on the aspect of damage resulting from glacial lake outburst floods. This time, however, in contrast, the emphasis was on environmental aspects – specifically, in the case of the Andean glaciers, on the resulting decline in water resources. We came to see that the same events associated with the phenomenon of glacial retreat may cause vastly different problems depending on the regional environment.

Then, in 2008, “Research on Glacial Lake Outburst Flooding in the Bhutan Himalayas” was selected as a subject for research by the Science and Technology Research Partnership for Sustainable Development (SATREP). In this long-term project, which extended over a period of three years, RESTEC was in charge of satellite activities, and we contributed to make a high-resolution glacial lake inventory in the entire area of Bhutan using ALOS data. Furthermore, RESTEC conducted regular training related to methods of analysis using not only ALOS data but also other currently-operated satellite data for on-site engineers, and was also able to carry out technical transfer so that, even after the use of ALOS was discontinued, the engineers were able to continue to carry out glacial lake monitoring by themselves, using other satellite data.

Our current main activity is the “Compilation of a Register of Glaciers in the Alpine Belt of the Argentinean Andes using ALOS High-Resolution Satellite Images” project, which is run by JICA. This project is being implemented to build a foundation for work in Argentina on a par with the work involved in the SATREPS Bhutan project, where the compilation of a glacial lake register was successfully completed. Our goal is that this project will be a spur the further development of other projects in the future.

There are high expectations for the potential contributions of glacier observation in many different areas, such as disasters and the environment. However, since on-site surveys in this field involve the study of mountains that are over 5,000 m high, this means that it is essential for researchers to have prior experience in staying overnight in low-oxygen rooms, climbing Mount Fuji, practice with climbing irons and ice axes on mountains in winter, and training to prevent falls, before even entering the areas for investigation.

Through the numerous on-site surveys we have conducted so far, it goes without saying that we have further developed our remote-sensing techniques. Our mountain-climbing skills have also improved considerably.

*A digital surface model compiled using ALOS/PRISM stereo pair images


Results of Bhutan analysis


GPS measurement for local survey