Estimation of blufflines using topographic lidar data and orthoimages

Coastal zone mapping, particularly of shorelines, is critical for safe navigation, resource management, environmental protection, and sustainable coastal development. This paper explains a method for extracting coastal blufflines where airborne lidar (Light Detection and Ranging) data is integrated with orthoimages. A historical Lake Erie bluff top line was used as a reference line and a series of transects created perpendicular to it. After three-dimensional elevation profiles of these transects were obtained from a lidar DSM (digital surface model), a new algorithm was used to extract from these transects initial points identifying bluff top and toe. These points were connected to form an initial bluffline. The horizontal position of this initial bluffline was refined with edges obtained from the orthoimages using techniques including mean-shift segmentation, surface reconstruction, and edge detection. Results show this method is capable of deriving blufflines having a similar quality to that from manual digitization.