Additional Information on the Flood Caused by the Outburst of

Figure 1: Glacial lakes in the Thame region and surrounding area (The large lakes within the marked boundary on the left are Lumding Tsho, and on the right, Dig Tsho) (Source: Google Earth Pro, December 2020) According to the analysis provided by Earth Observatory Singapore on the request of department, based on Sentinel-1 satellite images from August 7, 2024 (Sawan 19, 2081), and August 19, 2024. [...] The analysis indicated that the sudden land deformation below Glacial Lake 1 and above Glacial Lake 2 was the primary cause of the outburst of Glacial Lake 2 (Refer to Figure 2). [...] The analysis showed no change in the surface area of the other four lakes, while the surface area of Glacial Lake 2 decreased due to the outburst (Refer to Appendix 2). [...] Sentinel-1 and Sentinel-2 satellite images showed that the surface area of the lake was 0.045 square kilometers (km²) with 0.38 million cubic meters (MCM) before the outburst which decreased to about 0.011 km² after the event, indicating that approximately 88% of the water (around 0.34 million cubic meters) was released due to the outburst (Refer to Figure 5 and Figure 6). [...] 5 Figure 7 Area of Lake 1 from different dates Further analysis of Sentinel-1 satellite images from Earth Observatory Singapore showed that the flood caused significant ground deformation in the Thame area downstream of the outburst (Refer to Figure 8).