ZHANG Nan, ZHANG Yan, WANG Jiaxi, et al. Quantity and Morphological Parameters of Gullies in Small Watersheds in the Hilly-gully Loess Plateau[J]. 2023, 37(3): 109-115.
DOI:
ZHANG Nan, ZHANG Yan, WANG Jiaxi, et al. Quantity and Morphological Parameters of Gullies in Small Watersheds in the Hilly-gully Loess Plateau[J]. 2023, 37(3): 109-115. DOI: 10.13870/j.cnki.stbcxb.2023.03.015.
Quantity and Morphological Parameters of Gullies in Small Watersheds in the Hilly-gully Loess Plateau
Taking two small watersheds in the first sub-zone (Zone-1) and the fifth sub-zone (Zone-5) of the Loess Plateau as examples and based on UAV image (0.15 m) and DEM (1 m)
this paper aimed to analyze the characteristics of gully network
extract and analyze the quantitative characteristics of gullies as well as to compare morphological parameters of normal gullies and big gullies were based on random sampling. The results showed that: the gully channel system in Zone-1 is more complicate than that in Zone-5. The ratio of main gully channel to branches in the watershed in the first sub-zone was 1∶35.6
which was far larger than that in the fifth sub-zone (1∶22.0)
and densities of channels in Zone-1 was higher than that in Zone-5. Normal gullies were dominant in both zones with density of normal gully was 9.72 km/km2 in Zone-1 and 14.22 km/km2 in Zone-5. The number of big gullies were less than normal gullies
with density was 4.27 km/km2 in Zone-1 and 4.23 km/km2 in Zone-5. Most of normal gullies were grade 1 of channels in both zones
big gullies were belong to grade 1~3
and dry channel were mostly grade 3~5. Except for longitudinal gradient
other morphological parameters of normal gullies in Zone-1 were all smaller than the counterparts in Zone-5
while there was no obvious differences in big gullies in the two zones. Significant power function relationship between the gully volume and area were found for both normal gullies and big gullies in both zones. However
higher determinant coefficients implied that the morphology is more similar for same type of gullies in Zone-1 than that in Zone-5. The results can provide reference for accurate statistics of erosion gullies in the Loess Plateau and comprehensive management of soil and water conservation in small watersheds.
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