A Perspective on Rishiganga-Dhauliganga Flash Flood in the Nanda Devi Biosphere Reserve, Garhwal Himalaya, India

A ground-based and heliborne survey was conducted immediately after the disaster that took place on 7th February, 2021 in the Chamoli district of Uttarakhand. Based on these observations and freely available Google Earth imagery, we have arrived at plausible causes of this catastrophe as detachment of a sizeable rock mass and overlying hanging glacier in the Raunthi catchment that dammed the Rishiganga River and led to the devastation of roads, bridges and hydropower projects in downstream.