Figure 3. Recognition results of the SegNet model in the Zhoutungou watershed in 2021.
In 2021, there were 2,312 gullies in the Zhoutungou watershed, with a frequency of 68.81 per km² (Table 2). Gully lengths ranged from 5–209.5 m (average 45.84 m), with a total length of 105.98 km, and density of 3.15 km km². Gully widths ranged from 0.5–2 m, with more than 85% between 1 and 1.5 m. Gully area ranged from 5.36–209.5 m² (average 46.36 m²), with a total area of 0.1072 km² and dissection degree of 0.32%. Figure 2 and Table 2 reveal that the gullies in Zhoutungou watershed are crisscrossed and occur intensively, and some are connected in a cluster distribution. The morphological features of the gullies differ, with great uncertainty and chaotic characteristics, and no clear law of spatial distribution.
Table 2 Statistical characteristics of the morphological features of gullies in the Zhoutungou watershed in 2021