Multi-Temporal Landslide Volumetric Analysis and Suitability Evaluation of Multi-Sourced Dems in an Area Hit by Wenchuan Earthquake

The 2008 Wenchuan earthquake in Sichuan, China, dramatically changed the terrain surface by inducing large numbers of landslides covering an estimated area of about 811 km2 (Dai et al., 2011). In the following years storms triggered thousands of debris flows across the entire mountainous region, among which several were much larger than expected. The temporary shelters, roads and reconstructed buildings were damaged or destroyed in a number of locations. The triggering mechanism of the debris flows were concluded as the entrainment of the loose materials created by the co-seismic landslides(Tang et al., 2011; Xu et al., 2012). Many studies were carried out, however the volume the landslides over large areas was only estimated by the area-volume relationships(Dai et al., 2011; Parker et al., 2011; Tang et al., 2016; Xu et al., 2013). Volume measurement was only done on a few large landslides through drilling bore holes and applying geophysics methods. The trend of the total loose material volume change over the years remains unknown.