Being within a geo-dynamically active Himalayan belt, the state of Uttarakhand is more susceptible to natural hazards due to inherent geology, high relief, narrow valley, thick overburden, heavy downpour and rapid glacial melting etc. Over the past decades, these natural hazards have resulted in loss of human lives, infrastructures and properties along with other natural resources. The current issue highlights the natural hazards such as rock slides/falls, debris flows, moraines and avalanches which had blocked the streams and impounded the water, left behind the natural dams in the same regions. An attempt has been made to enlist the same in tabular form together with their location, year of occurrences and impacts. Total of 24 incidents have been reported between the year 1857 and 2018 of which alone 50 percent is to be recorded in Chamoli district while 25 percent in Rudraprayag district. Recent incidence of Lwarkha, Chamba Tehsil of Tehri Garhwal district is briefly discussed in this paper. The main aim of this study is to learn lessons from the past incidences and aware the local people from the threats of future natural damming of streams and associated outburst floods.
Natural dams, Northwestern Himalaya, Natural hazards, Consequences, Prevention measures