A new method for debris flow detection using multi-temporal DEMs without ground control points

摘要

Automatic DEM deformation detection without ground control points (GCPs) with its application in debris flow change analysis is an attractive but very difficult research topic. Based on the existing methods of M-LZD and LMS-LZD, this paper presents an improved method that takes both magnitude and relationship into account through allocating an appropriate weight to each observation and evaluating the contribution of each observation to deformation with the allocated weight. Such improvement enhances greatly the ability of DEM deformation detection. Compared with the M-LZD and LMS-LZD algorithm, using the multi-temporal DEMs of the Puwaigou valley, along the Hengduan mountain ranges in the southwest of China, where debris flows occur frequently during each summer due to heavy rainfall and each Autumn due to rapid snowmelt, the experimental results demonstrate that our method has the highest detection accuracy (RMS) and detection percentage (capability) of over 50%. The advantages of our method are (1) it does not need GCPs and prior information and knowledge of the terrain surface, and (2) it can calculate simultaneously the volume and determine the spatial distribution of terrain surface changes of multi-temporal DEMs.