Assessing the Relationship Between Landslide Occurrence and Causative Factors in the Upper Satluj River Basin, Kinnaur District, Western Himalaya
Abstract
In the Himalayan region, landslides are among the most frequently occurring geomorphic hazards, resulting in significant loss of life, degradation of natural resources, and damage to infrastructure. A spatial relationship between landslide occurrence and conditioning factors is fundamental for effective hazard assessment and risk mitigation. This study aims to explore the relationship between the thirteen causative factors and landslides in the Upper Satluj River Basin in Kinnaur district of Himachal Pradesh, by employing Chi-square (χ²) statistics and standardized residual analysis in a Geographic Information System (GIS) environment. For this, a landslide inventory consisting of 1543 landslide locations was prepared based on the data available in the Geological Survey of India (GSI) Bhookosh portal and field surveys. The results show that all the selected factors have statistically significant relationship with landslide distribution. Among them slope, relative relief, land use/land cover, and lithology emerged as the most influential controls. Standardized residual analysis suggests that landslides tend to be concentrated on steep slopes, on south facing slopes, moderate to high relief, structurally disturbed areas, shrub dominated landscape, fine-loamy soils and areas with low to moderate vegetation cover. The landslide occurrence is comparatively low in the areas with dense vegetation, sandy skeletal soil, and high TWI. The results show that the spatial pattern of landslides in the basin is controlled by the interplay of terrain morphology, geological conditions, and land-surface properties. The results of the study give insight into the environmental controls of landslide occurrence and serve as a scientific foundation for the landslide susceptibility assessment, landslide hazard zonation, and disaster risk reduction planning in the Himalayan region for the future.