4:45 PM - 5:00 PM
[STT48-12] Update of a glacial lake inventory in the Bhutan Himalaya using ALOS-2
Keywords:SAR, GLOF, Glacial lake inventory
The initial information is obtained from the glacial lake inventory released from the Japan Aerospace Exploration Agency, which contains geospatial information of the glacial lakes in the Bhutan Himalaya between 2006 and 2011. We use PALSAR-2 images observed the same site after 2014 for several times. They were acquired at the stripmap mode with spatial resolutions of 3 to 10 m. In a PALSAR-2 backscatter amplitude image, a lake surface is identified as low-value homogeneous pixels. Therefore a segmentation tool in QGIS/Orfeo Tool Box is used to extract the lake surfaces automatically.
As the result of segmentation on a PALSAR-2 image, almost all of glacial lakes which have ranges larger than 100 m were extracted, whereas small lakes were not able to be extracted resulting in small fragments. From this result, we are going to discuss influence of PALSAR-2 spatial resolution and several data processing which can be needed before lake extraction.