The topographic change of turtle mountain island with multi-temporal airborne LiDAR data

To obtain a big area of high-resolution topographic data in a short time using the LiDAR systems are nowadays largely used for quantitative analyses and modelling in geology, coastal erosion, and geomorphology. In this study, two topographic datasets taken in 2005 and 2011 in Turtle island, an active volcano island in Taiwan, are used to plot shadow relief maps firstly. Then the change analysis in the coastal area is performed. The change analysis results show that a fault feature occurred in the northern slope surface of Turtle island, and the coastal cliff avalanche tends to magnify at the turtle head. Moreover, the geomorphometric feature of accelerating erosion can also be clearly identified. It is concluded that geomorphometric features reflecting active processes can be clearly recognized using the detailed multi-temporal LIDAR data.