The challenge Landslides, also called landslips, refer to the movement of a mass of rock, debris or soil. Landslides are typically caused by rain (cloudbursts, long lasting monsoon rains), earthquakes but might also be triggered by human activities such as road construction. Landslides are sometime difficult to distinguish from to rock falls or mudflows; all of them have a destructive character due to their quick occurrence and high energy potential. Landslides have been identified as a key concern in the State of Uttarakhand, particularly in the Baghirati valley with over 0.6 million residents and 6.0 million pilgrims and domestic tourists yearly. Due to landslides every year roads are closed, villages are cut off and accidents happen.
Our approach and interventions The Swiss interventions related to landslide focus mainly on Uttarakhand (Baghirati valley).
- Remote Landslide susceptibility assessment using sensing study using Synthetic Aperture Radar data (SAR-data 2015-20) from free Satellite data. To identify and map deformations, instable zones
- Elaboration of a GIS based landslide inventory (Data collection, Satellite image processing) analysis and classification of over 4’000 landslide events
- Elaboration of precipitation-based landslide model (Landslide susceptibility Model) considering further multiple key characteristics (geomorphology, lithology, topography etc)
- Installation of 3 Automated Weather Stations (AWS) to collect real-time rainfall data
- Landslide susceptibility/hazard assessment, identification of hotspot areas
- Swiss expert field visit for the validation of landslide hotspot areas and recommendations
- Preliminary design of a landslide early warning system
- Survey and assessments to identify training and capacity building needs related to GLOFs EWS to identify relevant capacity building activities
Further assessments were also done in Sikkim (SAR-data analysis) and Himachal Pradesh (hazard assessment).
The above mentioned results are summarized in the following documents
- Landslide Monitoring through Sentinel-1 SAR Data (springer publication) (https://www.springerprofessional.de/)
- Advanced Remote Sensing Techniques for Landslide Susceptibility Assessment for Bhagirathi Valley, Uttarakhand (2020)
- SDC India, CC-DRR-E newsletter on “digitalization” (2023)
Collaboration with key partners The landslide analysis, the model set up and the preliminary EWS elaborated by a Swiss expert consortium (Geotest, University of Geneva, University of Zurich), the Swiss expert company SARMAP. Activities were carried out in close collaboration with the state government of Uttarakhand (State Disaster Management Authority – SDMA) and the State Environment Conservation and Climate Change Directorate).
