Factors affecting land dissection density in geomorphological regions of China

Land dissection density (LDD) provides morphological evidence regarding prior intense soil erosion and quantifies the distribution of land dissections. A comprehensive understanding of the potential factors influencing the spatial pattern and value of the LDD is vital in geological disasters, soil erosion, and other related domains. Land dissection phenomena in China affects large areas with different morphological, pedological, and climatic characteristics. Prior studies have focused on the potential factors influencing the LDD at a watershed scale. However, these results are insufficient to reflect the status quo of dissection development and its primary influencing factors on a national scale. LDD’s spatial patterns and the dominant factors at a regional scale in millions of square kilometers remain to be ascertained. This study used the geomorphon-based method and the geographical detector model to quantify the spatial pattern of LDD over China and identify the dominant factors affecting this pattern in China’s six first-order geomorphological regions (GR1∼GR6). The results yield the following findings: (1) LDD in China ranges from 0∼4.55 km/km², which is larger in central and eastern regions than in other regions of China; (2) dominant factors and their dominant risk subcategories vary with each geomorphological region’s primary internal and external forces; (3) the influence of natural factors is more significant on the large regional scale in millions of square kilometers compared to anthropogenic factors; relief degree of land surface (RDLS) is dominant in GR1, GR2, and GR5; the slope is dominant in GR6, soil type is dominant in GR3 and GR4, and lithology plays a critical role in the dominant interactions of GR3, GR4, and GR6; (4) the interactions between factors on LDD’s spatial pattern have a more significant effect than individual factors.