Preparing for future mass movements triggered by earthquakes and monsoon events in the Indian Himalayan Region (IHR) – learning from the 2015 Nepal event

In populated regions, high-magnitude earthquakes often have disastrous and long-term impacts on the society and the environment, particularly when people and infrastructure had not been well prepared for such events. On April 25 and May 12, 2015, strong earthquakes rocked Nepal, and destroyed infrastructure and buildings, damaged historic temples, killed several thousands and resulted in severe economic losses. Furthermore, the earthquakes triggered numerous mass movements (landslides, debris-flows, avalanches, rock falls) in the steep mountain slopes, which destroyed again infrastructure, and blocked roads, which hampered search and rescue in the remote areas of Nepal. With spring melt and especially heavy rainfalls from monsoon, additional mass movements followed (highest numbers of landslides normally occur in the monsoon season). The events in Nepal clearly show that the Himalaya-Karakoram region, including the Indian Himalayan Region (IHR), which is very similar to Nepal in terms of seismic, monsoon and high altitude topography, urgently needs to be better prepared for similar events in the future. Therefore, here, we propose to investigate the Nepal case and to derive knowledge for analogue regions such as the IHR, to learn and be better prepared in case of similar events in the future.

Accordingly, the objectives of the proposed FLASH research project are 1) to compile a database on past mass movements in two test regions (in the IHR and the earthquake affected area of Nepal) and to select a subset of mass movements with starting zones assignable to the glacial-periglacial environment, 2) to assign the possible triggers “earthquake” and “monsoon” to individual mass movements, and 3) to generate a first regional scale potential predisposition map on mass movement with focus on the glacial-periglacial environment in the IHR. These objectives are achieved within five concise work packages. The Swiss and Indian project team bring together strong expertise in climate related impact studies on different spatial and temporal scales, with focus on high mountain environments and with the required technical skills for successful completion of this study.

Prof. Andreas Linsbauer

Prof. Ashok Dimri