Journal des sciences de la Terre et du changement climatique

Abstrait

Orographic and Tectonic Control on Extreme Events with Special Reference to Uttarakhand Disaster of June 2013 in the Mandakini Valley, India

Nitu Singh*, Yogita Garbyal and Kishor Kumar

This study deals with the climate change and its impact on changing precipitation behaviour, consequent events of extreme rainfall (cloudburst), landslides and flash floods. In this work, TRMM (Tropical Rainfall Measuring Mission) 3B42RT(real time) precipitation data for 16 (1998-2013) years was utilized to understand the present variation of precipitation and extreme events such as cloudburst, flash floods, and landslides in Western Himalaya. It was observed that the extreme events are mainly restricted to the south of higher Himalaya, coinciding with high precipitation. Since, the higher Himalaya is bounded by MCT (Main Central Thrust), it could be envisaged that this zone has been acting as orographic barrier hence most of high precipitation and extreme events are confined below the area. This orographic barrier plays a significant role in controlling the expectancy and extent of high rainfall and thus triggering of the associated hazards like landslides. A case of Mandakini valley where Kedarnath disaster of June 2013 has caused loss of over five thousand lives and properties worth billions has been studied.