Large scale individual landslide remote sensing

Individual landslide remote sensing surveys are parts of a“digital landslide” technique that requires high spatial resolution RS images and combined with mid-spatial resolution images and GIS-dependant accurate spatial positioning.The Yigong and Tiantaixiang landslides as studied by remote sensing are two examples to explain its application.A recent RS+GIS study of the micro-geomorphologic structure of the Yigong landslide has demonstrated that Yigong sliding body moved at high velocity through a gorge and impacted a precipitous cliff changing to debris-flow.In addition,this study has revealed for the first time the depositional structure of a high speed debris-flow and proved a volume conversion relationship between the pre-sliding mass and the debris-flow deposit.For the Tiantaixiang landslide investigation,a new “special points” method has been proposed and with it the boundary and influence limitation of the landslide has been determined period.In addition,the sliding distance,orientation and velocity of various parts of landslide and the volume of the landslide have been calculated.It has been determined that before the 2004-09-05 landslide the Tiantaixiang slope was stable.Highway construction in 2003,initiated the landslide and heavy rainfall during 2004-09-03～05 had triggered its major movement.