Research progress and prospects of complex soil erosion

Abstract: Complex soil erosion is an erosion phenomenon that occurs under the interaction or coupling of two or more erosive forces, and is one of the most difficult ecological problems to be managed. In recent years, remarkable progress has been made in the mechanism of complex erosion, the effect of complex erosion on soil degradation, and the simulation technology of multi-dynamic erosion interaction. Based on previous research, this paper systematically summarizes the research progress of the types and characteristics, mechanism and research methods of complex erosion. The main problems in the research are analyzed, and some key scientific problems to be solved in the future research on the law of complex erosion and the method of simulation test are put forward. Due to the obvious spatiotemporal heterogeneity and the complexity driven by multi dynamics in complex erosion, the existing research results are still quite different, and the dynamic mechanism of the occurrence and development of complex erosion is still unknown. The research on theory and method of complex erosion simulation and quantitative assessment is still very weak. In particular, there is a lack of effective test key technology to reveal the multi power driving relationship. At present, the problems in the study of complex erosion mainly include: 1) The multi-dynamic interaction relationship in complex erosion is not studied as a complete dynamic system; 2) The spatial-temporal variation relationship between complex erosion process and environmental factors is not clear enough; 3) It is still a key problem to quantitatively identify the contribution rate of each driving factor in the process of complex erosion; 4) The quantitative research on the coupling and superposition of multi dynamic factors in the process of complex erosion is not enough. In the future, the dynamic mechanism of the occurrence and development of complex erosion and the simulation of multi dynamic decomposition will become the key research direction. Therefore, it is necessary to clarify the complex erosion model under multi dynamic interaction, clarify the feedback mechanism of vegetation pattern on complex erosion, reveal the coupling mechanism of ecosystem degradation and complex erosion under multi dynamic stress, establish the identification method of the coupling relationship between multi dynamic complex erosion and sediment yield, and break through the theory and technology of complex erosion simulation. This will promote the development of complex erosion research from qualitative to quantitative, from process to mechanism, and will greatly enrich the research content of soil erosion dynamics, ecology and other related disciplines. We should focus on the following research directions: the simulation technology of rainfall-wind tunnel-freeze-thaw multi-dynamic alternating cycle test based on multi-source data fusion, quantitative evaluation technique and method for driving factor in compound erosion system, identification and quantification of sediment yield process under different coupling conditions of multi-dynamics in order to provide reference for related research.