Application of the relief amplitude and slope analysis to regional landslide hazard assessments

Abstract：Based on the SRTM3-DEM data and by using the ArcGIS platform, the authors calculated and analyzed the relief amplitudes and slopes of the Ordos area and its vicinity, established the correlation among the relief amplitudes, slopes and landslide hazard occurrence using regional landslide hazard survey data, and discussed the geomorphological significance of the relief amplitude analysis. The results show that in the study area landslides mainly occur in areas with relief amplitudes ranging from 200 to 300 m. The landslides in this amplitude interval account for 48.5% of the total number of landslides and 20.3% of the total surface area of the study area. Those areas have relief slopes ranging from 10° to 18°, and the landslides with this slope interval account for 46.7% of the total number of landslides and 30.5% of the total surface area of the study area. Geomorphologically the areas of frequent landslide occurrence correspond to monadnocks, loess tablelands and loess ridges. Analysis of topographic features of longitudinal and latitudinal profiles across the study area shows that the relief amplitude and slope have a good correlation with the occurrence and distribution of landslides. This correlation provides a new idea for assessments of regional landslide hazards and is of great significance to regional geohazard planning and prediction.