Generation of DEMs for channel change of the river Feshie

This paper analyzed changes in the morphology of the River Feshie before and after the September 2022 flood using high-resolution DEMs. The DEM of the river channel in June and November 2022 was established by the UAV-SfM method, and the water depth of the submerged area of the channel was corrected by the refraction correction method based on the small angle approximation correction. Corrected DEMs of the two periods were compared to obtain the DEM of Difference (DoD). This DoD was used to monitor the change in the river channel. The results showed that the UAV-SfM method can perform high-resolution and high-precision topography reconstruction of the river channel at the middle scale, and the small-angle approximate refraction correction method can improve the water depth accuracy. The DoD result indicated that the River Feshie has sediment deposited in the channel after the flood, and the outcome of this study can feed the flood model for the River Feshie in the future.