Extraction of Waterfalls from DTM using OBIA: A Case Study of Mantayupan Falls in Barili, Cebu

摘要

Waterfalls are one of the beautiful and majestic land features which seize the imagination of poets and artists and have been tourist attractions for generations. With large volume of water falling down, waterfalls are also used to generate hydroelectric power. Determining the locations of waterfalls is important for tourism and energy resource management. This study focuses on waterfalls extraction using lidar derivatives and applying OBIA (object based image analysis) as a method for the determination of waterfalls' characteristics. The Mantayupan Falls in Barili, Cebu was used as the study area because of the visibility of the waterfalls in the aerial photo. To identify the waterfalls the drainage line of the terrain was used as thematic layer and the slope of the segmented objects were calculated. In our study, the drainage line segmented with slope greater than 20 degrees were considered as the possible waterfalls location. The two-level Mantayupan Falls was automatically identified using the generated rule set.