Landslide hazard vulnerability assessment using surface wave method coupled with slope stability analysis: a case study

Natural hazards like landslides can have devastating consequences. The study of landslide causes and their vulnerability assessment will assist in implementing appropriate mitigation approaches so as to protect lives and property. Landslides are complex phenomena that primarily depend on the geometry of the slope inclination and the soil properties. Soil characteristics are mostly determined by the shear modulus of the subsurface layers, which is often approximated from the observed shear wave velocity (V_s). This paper is focused on assessing the vulnerability status of a site, especially through applications of the multichannel analysis of surface waves (MASW) approach. Improvements in Landslide hazard safety will be aided by the identification of unstable slopes; hence it is necessary to create the quick and affordable method for safety evaluation that is envisioned in this study. The study displays a graphical relationship between V_H (average shear wave velocity) and Slope gradient (ϴ°) in order to detect the potentially unstable slopes. The proposed curve presented by inputting the Slope inclination and V_H will be helpful in identifying and categorizing the slope into high, low and medium risk zones. This graphical relationship was practically validated based on the data gathered from eight stations spread throughout the various areas of Itanagar capital complex, Arunachal Pradesh, India. It was found that the relationship developed showed good prediction performance. The vulnerability of a landslide hazard can therefore be assessed using that vulnerability assessment curve by keeping an eye on monitoring the shear wave velocity and slope gradients.