Abstract:

Digital soil mapping is a novel and efficient soil mapping technique that utilizes 3S technology and is theoretically based on soil formation science, geography and mathematics. Domestic and foreign scholars had conducted extensive research on the generation of environmental collaborative variables, the acquisition of sample data, the selection of digital soil mapping models or methods, and the generation and validation of soil maps, especially on mapping methods. This paper introduced five categories of digital soil mapping techniques, including geostatistical methods, deterministic interpolation, mathematical statistics, machine learning, and expert knowledge models. At the same time, the mapping method suitable for the study area was chosen based on the merits of various approaches, from the aspects of target variables, topography and geomorphological features, sample density and distribution status and more. The future development direction of digital soil mapping included incorporating human activity factors into environmental synergistic variables; establishing more effective sampling methods based on machine learning and data mining; the application of new modeling methods (deep learning and multimodal methods).

Key words: digital soil mapping, soil properties, digital soil mapping methods, machine learning