3.1 Temporal and spatial changes in ephemeral gullies
The SegNet model was applied to the UAV image of the whole Zhoutungou watershed in 2021, with the sliding window and ignoring edge detection methods used to identify ephemeral gullies at the watershed scale (Fig. 4 (a)). Comparing the ephemeral gully identification results with the field survey in Fig. 4 (b), we found that the SegNet model had >91.66% accuracy for ephemeral gully number and spatial distribution accuracy.