Background It has formed a unique surface and underground dual erosion environment system under long-term karstification in the karst area of Southwest China. The inlaid distribution of exposed bedrocks and soils in the rocky desertification area with the obvious bedrock exposed shapes the most complex system of erosion environment in the karst area, which presents its uniqueness in the composition and action characteristics of erosion environment. However, there is still a lack of systematic understanding in the erosion environment compared with other geographical areas, such as the Loess Plateau area, the Northeast Black Soil Area, etc.

Methods Based on the previous research results in the soil erosion through field investigations, positioning tests and indoor analyses in the rocky desertification area of Guizhou province, China, this paper deeply analyzed and summarized the compositions of the dual erosion environment, the erosion objects, the erosion types, the erosion dynamic factors and action characteristics on surface erosion or underground leakage loss in the rocky desertification area.

Results The erosion environment has typical characteristics of vulnerability, complexity and variability in the area. In terms of composition, the erosion environment can be divided into three aspects: erosion power, erosion object and erosion interface. The erosion power includes external forces such as water power (rainfall, rock surface flow and surface runoff), gravity and human factors, as well as internal forces such as karstification and rocky desertification. The erosion objects include soil, humus, rock and rock weathering. The erosion interface includes surface and underground, soil-rock interface, water-soil interface, water-rock interface, rock/soil gas interface and rock/soil biogenic interface, etc. In this unique erosion environment background, the soil erosion in this area presents a dual erosion mechanism of surface erosion and underground leakage. The surface erosion mostly occurs in the form of water erosion, while the underground leakage superimposes the coupling effect of water erosion, gravity erosion and chemical dissolution. Finally, the key points and suggestions for soil erosion research are discussed in the karst rocky desertification area.

Conclusions Future research on the soil erosion in the karst rocky desertification areas needs to focus on the action mechanism of erosion dynamic system and erosion interface system on soil surface erosion and underground leakage, and further clarify the occurrence process, mechanism and influencing factors of various types and forms of soil erosion, especially the formation causes, distribution areas and sensitive influencing factors of gravity erosion such as karst collapse, which is easy to cause disasters, and then establish the theoretical system of surface erosion or underground leakage resistance control. This study is helpful to deepen the understanding of erosion environment, and provide theoretical reference for the study of surface erosion/underground leakage in the rocky desertification area.