Environmental and economic impact of cloudburst-triggered debris flows and flash floods in Uttarakhand Himalaya: a case study

Abstract

This paper examines the environmental and economic impact of cloudburst-triggered debris flow and flash flood in four villages of Uttarkashi district, Uttarakhand Himalaya. On 18th July 2021 at 8:30 p.m., a cloudburst took place on the top of the Hari Maharaj Parvat, which triggered a huge debris flows and flash floods, affecting 143 households of four villages of downstream areas. Immediately after the cloudburst occurred, the authors visited four affected villages—Nirakot, Mando, Kankrari, and Siror. A structured questionnaire was constructed and questions were framed and asked from 143 heads of affected households on the impact of debris flows and flash floods on people’s life, settlements, cowsheds, bridges, trees, forests, and arable land in and around the villages. The volume of debris, boulders, pebbles, gravels, and mud was assessed. It was noticed that all four villages got lots of destructions in terms of loss of life—people and animals, and property damage—land, crops, and infrastructural facilities. This study shows that the location of the settlements along with the proximity of the streams, which are very violent during the monsoon season, has led to the high impact of debris flow on the affected villages. We suggest that the old inhabited areas, which are located in the risk zones, can be relocated and the new settlements can be constructed in safe places using suitability analyses.

Understanding flash flooding in the Himalayan Region: a case study

“…These rapid floods are the outcome of a combination of natural and human factors, including geological movements, glacial lakes, steep topography, deforestation, alterations in land usage, and the monsoon season 68 . In the Himalayan region, the primary trigger for these abrupt floods is often linked to instances of cloud bursts accompanied by heavy rainfall episodes 69 . This study aims to provide insight into historical and recent instances of significant rainfall that have resulted in flash floods, while also examining the relationship between these events with atmospheric and other relevant factors.…”

Flash flood dynamics in the foothills of NW Himalaya: Insights into hydrological and geological controls

“…This expansion has far-reaching environmental consequences at regional and global scales (Bhat et al, 2017;Thapliyal and Panwar, 2020). In the case of Dehradun, construction in ecologically sensitive areas, like riverbanks, terraces, and unstable slopes, increases ood risks (Khanduri and Sajwan, 2019;Sati and Kumar, 2022).…”

“…Flash oods, often a result of cloudbursts, can be exacerbated by human activities. Deforestation and increased infrastructure development in river valleys contribute to damage in vulnerable areas (Chalise and Khanal, 2001;Rao et al, 2014;Sati and Kumar, 2022). Changes in land use and cover, along with deforestation and increased concrete surfaces, lead to reduced in ltration and increased surface runoff (Sati 2013).…”

Out-migration from the Hills of Garhwal Himalaya: a Case Study

“…Additionally, agricultural growth has declined and it is no longer a remunerative sector. Further, unsuitable development programs and policies, large scale poverty, livelihood restrictions, lack of high-quality educational institutions, unplanned urbanization, limited industrial growth, changing climate, and increasing frequency and intensity of natural hazards and disasters (Sati and Kumar, 2022), and the growing risks of food and livelihood insecurity have contributed to accelerating rural out-migration from the Garhwal Himalaya.…”