Early Warning of Water-Triggered Landslides

. Landslides are a major societal threat, causing adverse consequences to life, economy and environment. Mitigation of the potential negative effects of landslides commonly involves deployment of challenging and costly measures. This is often the case in the development and operation of linear infrastructures such as road, pipeline, and railway networks in land-slide prone areas. One of the commonly employed measures for mitigating the adverse consequences involves monitoring of landslide triggering param-eters and issuing timely warnings. Given that the landslide triggering param-eters (e.g., large weather systems, local man-made triggers) and the linear in-frastructures span varying spatial scales, there is a need for developing a landslide monitoring and early warning system for both regional as well as local scales. This paper presents a brief introduction of the Norwegian prac-tice for early warning of landslides triggered by extreme weather on regional scale, which has proven to be effective. The criteria for issuing an early warning are based on the degree of saturation of soil and the supply of water to it through rainfall and snow melting. On other hand, monitoring of single slopes on local scales can be quite challenging and expensive. In order to provide landslide monitoring systems of single slopes in affordable price, In-dian Institute of Technology Mandi developed a low-cost landslide monitor-ing and early warning system. These systems are deployed in Mandi district of Himachal Pradesh, India and monitoring fifteen plus landslide locations. A recent case study is also discussed in this paper where these systems helped in alerting people and traffic from an impending landslide.