Brzank et al.,2009) presented a new method to detect and evaluate morphologic changes of the Wadden Sea based on the extraction of structure lines of tidal channels from lidar data.Chien and Lin (2010) developed a new method, namely double threshold strategy, to find changes within 3-D building models in the region of interest with the aid of lidar data. Their modelling scheme comprises three steps, namely, data preprocessing, change detection in building areas, and validation.