Investigating the 7th February, 2021 Landslide Triggered Flash Flood in the Himalayan Region Using Geospatial Techniques

A rapid landslide on Ronti Mountain, part of the Nanda Devi Biosphere Reserve, triggered a catastrophic flash flood in the Rishi Ganga/Dhauli Ganga River system on February 7, 2021. The event, caused by a combination of heavy snowfall and rising temperatures, resulted in a high-velocity (198 m/s) landslide that descended from ~5900 m to ~3900 m elevation within approximately 20 seconds, generating moraine-filled floodwaters that surged downstream. Geospatial datasets—including MODIS, Sentinel-2B, SRTM, ICESat-2, and ERA5—revealed pre-existing conditions of weathering and erosion on the mountain's back-slope, contributing to instability. The study highlights how climate-induced factors exacerbated landslide risk in this UNESCO World Heritage Site, emphasizing the need for integrated monitoring of such vulnerable regions.

Dandabathula, G., Sitiraju, S. R., & Jha, C. S. (2021). Investigating the 7th February, 2021 Landslide Triggered Flash Flood in the Himalayan Region Using Geospatial Techniques. European Journal of Environment and Earth Sciences, 2(4), 75–86. https://doi.org/10.24018/ejgeo.2021.2.4.170