Active River Area (ARA) Framework Refinement: Developing Frameworks for Terrace and Meander Belt Delineation and Defining Optimal Digital Elevation Model for Future ARA Delineation

Abstract

The Active River Area (ARA) is a spatial approach for identifying the extent of functional riparian areas, with five components (floodplains, terraces, riparian wetlands, meander belts, material contribution zones). Given the limitations in terms of input data quality and methodology, this framework cannot specifically differentiate terraces from floodplains and identify the river meander extent. To address these limitations in the ARA framework, this study developed a floodplain and terrace separation framework and a meander belt delineation framework. Their applicability was tested in two study watersheds in New Brunswick. Moreover, to determine the optimal input DEM for future ARA studies, this study developed an accuracy-efficiency tradeoff analysis framework and assessed ARA outputs derived from a range of DEM inputs for accuracy and efficiency. It has been found that 5-m smoothed LiDAR DEM is best able to balance final ARA accuracy and data processing efficiency and ultimately recommended for future ARA delineations.