The morphological characteristics of gully systems and watersheds in Dry-Hot Valley, SW China

• 作者: Zhen Xu Fachao Qin Bin Zhang Qingchun Deng Hui Liu Jie Jin Liangtao Shi
• 来源期刊: 地球化学学报(英文）
• 关键词: Morphological characteristics Quantitative relationships Gully system Watershed Dry-Hot Valley
• 年，卷（期）: 2018,（6）
• 页码范围: 854-866
• 页数: 12页
• 语种: 英文
• DOI: 10.1007/s11631-018-0299-y

摘要

Gully systems and watersheds are geomorphic units with clear boundaries that are relatively independent of basin landscapes and play an important role in natural geography. In order to explore the morphological characteristics of gully systems and watersheds in the Dry-Hot Valley [South West (SW) China], gullies are interpreted from online Google images with high resolution and watersheds are extracted from digital elevation model at a scale of 1:50,000. The results show that: (1) There are 17,382 gullies (with a total area of 1141.66 km2) and 42 watersheds in the study area. (2) The average gully density of the study area (D) is 4.29 km/km2, gully frequency (F) is 14.39 gullies/km2, the branching ratio (B) is 5.13, the length ratio (L) is 3.12, and the coefficient of the main and tributary gullies (M) is 0.06. The degree of gully erosion is strong to extremely strong, the main development intensity of gully erosion ranges from intense to moderate, and the type of gully system is tributary. (3) The watershed areas (A) are between 0.39 and 96.43 km2, the relief ratio (R) is from 0.10 to 0.19, the circularity ratio (C) is from 0.30 to 0.83, the texture ratio (T) is from 0.82 to 39.35, and the dominant geomorphological texture type is fine. (4) There is a quantitative relationship between F and D:F = 0.624D2 (R =0.84) and T is closely related to D, F, M (R2[0.7). A, R and C are related to M (R2[ 0.5). The development of gully systems is the result of coupling effects between multiple factors. In this area, the degree of erosion and the condition of the main and tributary gullies can be controlled by the degree of topographic breakage in the watershed, which provides some theoretical basis for the evaluation of gully erosion by the latter. In addition, the scale, relief, and shape have a significant impact on the locations of the main and tributary gullies. For tributary gullies, attention should be paid to the interception and control of runoff and sediment in the smal