GSIS: A 3D geological multi-body modeling system from netty cross-sections with topology

Abstract

True 3D geological models are instrumental in addressing practical geology problems. A 3D geological modeling method is a vital module which converts raw data in lower dimensions into 3D bodies. To be geologically practical, the method must take cross-sections as the main data source and must be capable of modeling areas with complex faults, maintaining data consistency as well as carrying out multi-body modeling. To realize such a practical geological modeling system, GSIS (Geological Spatial Information System) is developed based on the core method of 3D geological multi-body modeling from netty cross-sections with topology. According to the intersecting netty cross-section approach, the presented method divides the modeling area into several cross-section grids. Thus, the modeling is simplified into the independent modeling of each cross-section grid and their merger into an integrated model. Different approaches are employed when constructing models in a specific cross-section grid, depending on whether a fault is present in the grid in question. In the absence of a fault, the basic approach is employed; otherwise, the basic approach is extended to add fault-related treatments. In both approaches, arcs are classified into subsets by their connections, attributes, and topological relationships. Arcs in the same subset of the lowest level are triangulated and interpolated to generate stratum interfaces. In this work, the application of GSIS in the Beijing multi-parameter stereo geological survey project is presented. Among seven successfully constructed models, the engineering geological model of the new city zone in Shunyi district and the bedrock geological model of the central city zone are cited as examples. These demonstrate GSIS’s capacity in modeling large areas with complex geology.