GIS-based landslide hazard zonation model and its application

Multi-source earth observation data are highly desirable in nowaday landslide hazard prediction modeling. Landslide Hazard Zonation (LHZ) is a very important content of landslide hazard prediction modeling. In this paper, take Wan county for instance, we investigate the potentials of derivation from hybrid data sets to study landslide hazard zonation based on the ordinal scale relative weighting-rating technique. LHZ is then performed with chosen factor layers including: buffer map of thrusts, lithology, slope angle and relative relief calculated from DEM, NDVI, buffer map of drainage and Lineaments extracted from the digital satellite scene (TM). Then the Landslide Hazard Index (LHI) value is calculated and landslide hazard zonation is decided by slicing LHI histogram. The statistics demonstrate that High stable slope zone, Stable slope zone, Quasi-stable slope zone, Relatively unstable slope zone, Unstable slope zone and Defended slope zone account for 2.20%, 14.02%, 39.88%, 28.27%, 12.17% and 3.47% respectively. Then, GPS deformation control points on the landslide bodies are used to verify the validity of the LHZ technique.