Potential of UAVs for Monitoring Mudflat Morphodynamics (Application to the Seine Estuary, France)
Intertidal mudflats play a critical role in estuarine exchange, connecting marine and continental supplies of nutrients and sediments. However, their complex morphodynamics, associated with a wide range of physical and biological processes, are still poorly understood and require further field investigation. In addition, mudflats are challenging areas for Structure-from-Motion (SfM) photogrammetric surveys. Indeed, the mudflats generally hold back residual tidal water, which can make stereo restitution particularly difficult because of poor correlations or sun-glint effects. This study aims to show the potential of light UAVs (Unmanned Aerial Vehicles) for monitoring sedimentary hydrodynamics at different spatial scales in a silty estuary. For each UAV mission an orthophotograph and a Digital Elevation Model (DEM) are computed. From repeated surveys the diachronic evolution of the area can be observed via DEM differencing. Considering the ground texture in such a context, the stereo restitution process is made possible because of the high spatial resolution of the UAV photographs. Providing a synoptic view as well as high spatial resolution (less than 4 cm), the UAV dataset enables multi-scale approaches from the study of large areas to the morphodynamics of smaller-scale sedimentary structures and the morphodynamics impact of plant ground cover.
Jaud Marion, Grasso Florent, Le Dantec Nicolas, Verney Romaric, Delacourt Christophe, Ammann Jerome, Deloffre Julien, Grandjean Philippe (2016). Potential of UAVs for Monitoring Mudflat Morphodynamics (Application to the Seine Estuary, France). Isprs International Journal Of Geo-information. 5 (4). -. https://doi.org/10.3390/ijgi5040050, https://archimer.ifremer.fr/doc/00326/43721/