Unmanned Aircraft System (UAS) Photogrammetry for Tracking Streambank Erosion and Geomorphic Change along a Protected River Corridor

Excessive erosion and bank failure within river corridors pose a significant risk to infrastructure and natural systems and reliable characterization of bank erosion is a critical component when designing mitigation strategies and conducting post-restoration monitoring. Advances in unmanned aircraft system (UAS) and digital photogrammetry techniques provide a powerful new tool for capturing high resolution topographic data at less cost. This case study focuses on a 1-km section of the New Haven River in central Vermont, located in the northeastern United States. The New Haven River reach has exhibited instability due to its sensitive landscape position and history of watershed and channel disturbances. A fixed-wing UAS was deployed repeatedly over a two-year period (2016–2018). Digital elevation models (DEMs) and DEMs of difference quantified the volumetric change along the survey area where notable erosion and deposition occurred. Results showed the UAS to be capable of producing high quality topographic data at fine resolutions and an effective method for monitoring continued bank erosion.