Clustering gully profiles for investigating the spatial variation in landform formation on the Chinese Loess Plateau Clustering gully profiles for investigating the spatial variation in landform formation on the Chinese Loess Plateau

最小化 最大化

Vol18 No.10:2742-2760

Title】Clustering gully profiles for investigating the spatial variation in landform formation on the Chinese Loess Plateau

Author】CHENG Yao1,2; LI Jing-wei1,2; XIONG Li-yang1,2,3*; TANG Guo-an1,2,3

Addresses】1 Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing 210023, China; 2 School of Geography, Nanjing Normal University, Nanjing 210023, China; 3 Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China

Corresponding author】XIONG Li-yang

Citation】Cheng Y, Li JW, Xiong LY, et al. (2021) Clustering gully profiles for investigating the spatial variation in landform formation on the Chinese Loess Plateau. Journal of Mountain Science 18(10).  https://doi.org/10.1007/s11629-021-6869-1

DOI】https://doi.org/10.1007/s11629-021-6869-1

Abstract】The gully is the most dynamic and changeable landform unit on the Loess Plateau, and the characteristics of gully landforms are key indicators of gully evolution. Different gully profiles are connected and combined through runoff nodes. Thus, it is necessary to cluster gully profiles into a gully profile combination (GPC) to reveal the spatial variation in gully landforms throughout the Loess Plateau. First, the gradient and gully evolution index (GEI) of two sample areas in Changwu and Suide in Shaanxi Province, China are calculated and analysed based on GPC. Then, the gradient and GEI are calculated by using 90-m-resolution digital elevation model (DEM) data for the severe soil erosion area with the basin as the research unit. On this basis, the spatial variation in the development degree is analysed with Getis-Ord Gi*. The results show that the degree of gully undercutting decreases from southeast to northwest under the influence of rainfall. Due to the soil properties, the loess in the northwest is more prone to collapse, resulting in the decrease of GEI from northwest to southeast. The development degree of gullies is closely related to rivers. The strong erosive capacity of rivers leads to greater differences in gullies within the basin. At the same time, the skewness and kurtosis of the gully index in the basin are correlated; when the distribution of the gully index in the basin is less normal, the distribution of the gully index is more concentrated. These results reveal the spatial variation characteristics of the Loess Plateau based on GPC.

Keywords】Gully profile combination; Spatial variation; Digital elevation model; Loesslandform; Terrain analysis