Effects of Digital Elevation Models on Spatial Characterisation of Landslides in the Kalka-Shimla Region of the Indian Himalayas

Landslides are complex geohazards responsible for damage to life, the natural environment, and essential infrastructures like buildings, roads, and transmission lines in mountainous regions. The modeling of topographic input parameters for landslide-related investigations is often based on Digital Elevation Models (DEMs), which serve as a crucial geospatial data source. The present study attempts to analyze the effects of DEMs, obtained from different sources and varying in spatial resolution, on terrain feature estimation and spatial characterization of landslide-affected areas in the Indian Himalayas. Carto-DEM version 3R1 and ALOS PALSAR DEM are used to generate two geodatabases of DEM-derived landslide causative factors, each including digital maps of Elevation, Slope, Aspect, Curvature, Terrain Ruggedness Index, and Distance to Drainage. The generated geodatabases are utilized for conducting a spatial frequency distribution analysis to characterize the selected area into spatial bins with similar topographic characteristics. A comparative study of this analysis reveals that both the DEMs exhibited comparable topographic characteristics on a general level. However, considerable variations are observed when both the geodatabases are scrutinized closely. The results of this study highlight that the quality of the DEM used may affect its usability in a specific investigation and hope to add to the scientific discourse on the effects of DEM on landslide-related studies.