In slope disasters which increase recently, falling rocks from steep slopes occur even checked-location by preliminary survey. It is important to confirm the existence of falling rock and its origin corresponding to the preliminary survey in the steep slope maintenance, but it has problems of visibility as vegetation and steep slope safety. The efficiently preliminary survey has important to take acquire detailed topographical data. Airborne Laser Scanning and Terrestrial Laser Scanning with remarkable improvement in performance has been widely known as a surveying technique for acquiring topographic data with a high accuracy.
In this study, Three-dimension point cloud by aircraft and terrestrial laser Scanning were used in combination with objects on steep slopes facing river. Scanning were made at multiple times. We have evaluated the landslide variation amount with a high accuracy by discriminating characteristic land features from digital elevation model, which is Substratum Digital Elevation Model （S-DEM）and ICP analysis. We also describe the result that it is possible to predict the movement of steep slope occurred in the area. These methods are effective of the preliminary survey for steep slope maintenance.