Remote Sensing of Barrier Island Morphology: Evaluation of Photogrammetry-derived Digital Terrain Models

Abstract

This study evaluates the use of detailed, highly accurate digital terrain models (DTMs) in the study of coastal processes. DTMs are digital cartographic representations of the continuous surface of the ground by a large number of selected points with known X, Y, and Z coordinates. Advances in Geographic Information Systems (GIS) and terrain modeling software allow these models to be easily manipulated for analysis of coastal morphology. The DTMs in this study were derived using high-accuracy photogrammetric techniques. We compare 101 ground-surveyed beach and dune profiles and profiles derived by interpolation of a terrain model of the area. The model is found to be sufficiently accurate to measure changes in the dune field. Aerial surveys currently cost 1.5 times more than ground surveys. Examples of the spatial richness of the DTMs are also presented, including one application in coastal hazard mitigation.