Exploration of classification standards and map compilation methods for ground substrate: A case study of Yalu River Basin in Inner Mongolia

The ground substrate concept was proposed based on earth system science theories, with the purpose of serving and supporting the integrated management of natural resources. The essential properties of ground substrate were deeply analyzed from three aspects, that is material properties, spatial characteristics and ecological function, based on the concept of ground substrate, and its connotation characteristics were elaborated. The main issues in the current classification scheme were listed on the basis of researching the hot spots in the field and combined with practical experience. Based on the analysis of related issues and the principle of “scientific, prioritization, uniformity and popularity”, the authors formulated new three-level classification scheme. The new classification includes 5 first-level, 19 second-level and several third-level categories. Yalu River Basin in the eastern Inner Mongolia was selected as the study area based on this new scheme and new mapping approach was proposed as construction of vertical configuration at a constant depth in ground substrate layer. And the ground substrate map was compiled by fieldwork measurement and laboratory data. This study could effectively promote the close integration of ground substrate survey and application services, and also has significant reference value for technical methodology establishment.