17:15 〜 19:15
[ACG37-P03] Temporal Volumetric Changes of a Coastal Dune from Historical Aerial Imagery Processing
キーワード：Aerial photogrammetry, Beach evolution, Morphological change, Coastal dunes, Ortho mapping, Volumetric changes
Coastal dunes are dynamic landforms that are susceptible to changes due to a range of factors. Over time, these coastal environments experience erosion, accretion, and morphological changes that influence their stability and function. Understanding these changes is crucial for predicting future conditions, mitigating erosion risks, and ensuring effective management. In locations where observational data are scarce, aerial data sources serve as valuable tools for coastal management, sediment budgeting, and environmental monitoring. This research aims to evaluate the temporal volumetric changes of coastal dunes by utilizing historical aerial imagery in a data-rich area, such as Hasaki Beach. Historical aerial imagery obtained from the Geospatial Information Authority of Japan (GSI) is used to capture long-term beach evolution, covering multiple time periods between 1983 and 2012. The research employs ortho mapping techniques using Metashape software to generate dense point clouds from historical aerial imagery. These point clouds reconstruct object surfaces from overlapping aerial images and are used to build historical Digital Terrain Models (DTMs). The volumetric changes are calculated by performing a Digital Elevation Model (DEM) of Difference (DoD) analysis on the historical DTMs. This research identifies sediment redistribution along the beach and evaluates long-term beach evolution. The findings contribute to the applicability of aerial imagery in explaining volumetric changes in coastal dunes.