ABSTRACT
Indian Himalayas often faces natural calamities like earth quakes, landslides, flash floods, ice and snow avalanches and other extreme weather events. Himalayan flash floods have surprised and tested the natives of Uttarakahnd time and again. On 7th February 2021, on a clear day, one such massive and unexpected flash flood event occurred near Tapovan in Chamoli district of Uttarakhand. Tapovan lies in the environs of the Nanda Devi national park in Garhwal Himalayas. This event damaged Rishiganga hydropower station and a BRO bridge (Near Rairai village), about five other small bridges and another under construction hydro power project of NTPC at Tapovan. This event also led to significant loss of life, mostly people working in hydro power projects.
This paper presents an investigation of possible causes and flow dynamics of the subsequent debris flow event of Chamoli disaster using satellite images, field observations and flow simulations. Possible mitigation measures along with their limitations and challenges in their implementation are also presented. In addition, the paper also highlights the requirement of multiple mitigation measures for management of geo-hazards in the region and discusses the complexities and challenges in their implementation.
