The dynamics of marsh-channel slump blocks: an observational study using repeated drone imagery

We analyzed the spatial and temporal dynamics of slump blocks within Dean Creek, a creek located on Sapelo Island (GA) and surrounded by salt marsh. To accomplish this, we utilized 11 images of Dean Creek captured between March 2020 and March 2021, which were acquired by using a DJI Matrice 210 UAV. For each image, we manually digitized the perimeters of slump blocks, which have the distance from intact marsh boundary exceeding 0.3 m. These digitized perimeters were subsequently converted into polygons to determine the size, number and cumulative area of slump blocks in each image. Temporal changes to the slump blocks between subsequent images were also analysed. The coordinate system of these polygon data is WGS 1984 UTM Zone 17N.