Abstract: Geological investigation is a basic work in hydraulic project construction. The traditional geological survey records geological information on paper. However, this leads to a poor intuitiveness of the two-dimensional map and even a loss of its spatial features, and the field analysis process has to rely on subjective experiences heavily; disconnection of office work from field work makes it difficult to ensure data recording and analysis efficiency or data reliability. This paper presents an integrated method of 3D real scene recording and office-field analysis for hydraulic engineering geology. This system is based on the 3D real scene technology, Geographic Information System (GIS), machine learning algorithm, and geological modeling, focusing on the development of multi-source data fusion, multi-platform collaboration and 2D and 3D linkage, geological intelligence recording, and fast spatial interpretation. We develop two sets of platforms suitable for desktop and mobile terminals, including three main modules: 1) A base map module constructs a fused 3D reality using multi-source data and achieves multi-platform collaboration as well as 2D and 3D linkage of data, thereby providing reference scenes for office work and field work; 2) A recording module adopts a multi-platform collaboration and intelligent recognition method to implement the recording of geological points, geological boundaries, and exploration objects; 3) An analysis module, based on spatial interpretation, calculates spatial occurrence planes and makes inference about three-dimensional spatial intersection lines. In terms of specific functions, the mobile terminal focuses on field acquisition, while the desktop terminal on indoor analysis; both cooperate to achieve a seamless connection between office work and field work. The system has been applied to the geological survey of a hydraulic project in western China, and it shows a significant improvement on geological recording efficiency and quality in comparison with the traditional survey.

Key words: hydraulic engineering, geological exploration, integrated office-field analysis, multiple platforms, 3D real scene model, geological recording, spatial interpretation