Application of the relief degree of land surface in landslide disasters susceptibility assessment in China

Chinese mountainous area takes 2/3 of its total land area, making it one of the countries most seriously effected by landslide disasters, and the impact of landslide on people´s lives and property becomes increasingly serious. Considering the grim situation of landslide disasters and the resulting huge losses, it is a very important work to assess the susceptibility of the landslide disasters under national scale in order to provide the scientific basis for landslide disasters prevention. In many factors affecting the appearance of landslide disasters, such as lithology, geological structure, earthquake zone distribution, etc, the geomorphologic form is one of the main factors to control the spatial distribution of landslide disasters in China, also plays an important role as the main factor in the assessment of the landslide susceptibility. The relief degree of land surface is an important reference factor of geomorphologic form classification used to describe and reflect the macroscopic characteristics of topography of the surface in a large area. This paper extracts the relief degree of land surface of China based on the SRTM DEM covering the whole country. Based on the extraction, classify the national geomorphologic form into slow undulation, the low undulation, the moderate undulation, mountainous undulation and alpine undulation based on the classification to the relief degree of land surface with the range of 0~25m, 25~75m, 75~200m, 200~600m and >600m. It analyses the spatial correlation between different landscape patterns and the spatial distribution of the landslide disasters using the information content model. The results show that there is a very good correlation between the relief degree of land surface and the landslide susceptibility, with the increase of the value of relief degree of land surface, its information content gradually increases.