Assessment of Rainfall-Induced Landslide Susceptibility Studies Along NH-34, Uttarakhand Using Numerical Analysis

Landslides during the monsoon are a common phenomenon in hilly areas of Uttarakhand, resulting in loss of life and property and affecting the transportation system. Recently, landslide occurrences along the roads in Uttarakhand have been increasing due to frequent un-engineered anthropogenic activities. Due to this, there is an increased risk of traffic movement, particularly during the monsoon period. The present study area is on NH-34, which is a Char Dham Yatra highway in Narendranagar, Uttarakhand. According to the map of Uttarakhand’s Landslide Hazard Zone, the current study area falls under a high risk of landslides. This study investigates the possibility of landslide susceptibility along this road section, considering variations in rainfall intensity and slope angles. Using commercially available numerical software GeoStudio (SEEP/W and SLOPE/W), the studies were performed considering equivalent field conditions in the region. The required input parameters were chosen for the numerical analysis based on the samples collected from the field and site observations. The slope’s safety factor was estimated, and critical parameters influencing the stability of the slope were discussed.