General ideas for urban geological survey in China and key theory and techniques

In recent years, urban geological survey has been carried out in some city groups, big cities and small towns of China and, as a result, obtained great achievements in survey and evaluation of urban geological resources, geological environment, urban development space, and system construction of geological information service in urban management and some other aspects, and gained some experience in the survey methods, products, services, and coordination mechanism. However, compared with the requirements of new urbanization, there are still many shortcomings, such as backward work concept, slow updating of geological information, lack of standard systems, and imperfect working mechanism. In the national new urbanization development strategy, a new concept on urban development has been proposed. Urban geological survey is imperative to support the optimization of city layout structure, the expansion of urban development space, the promotion of green city construction, the improvement of city safety level and so on. In the new period, urban geological survey should be carried out with new ideas and the concept of big resources, big environment and big data. A comprehensive survey, which includes space, resources, environment, disaster and other factors, is required to serve urban planning, construction, operation, management and some other aspects. It also needs the development of three-dimensional visualization underground geological model for cities (transparent cities), the improvement of monitoring networks on geological resources and environment, the establishment of an open, shared and dynamic updating city geological information service and decision support system, the development of service product system, urban geological survey technical standard system and security system. In order to achieve this goal, it is necessary to establish the theory on urban resources and environment carrying capacity, urban multi-layer interaction zone and underground space resources collaborative planning so as to study and solve these technical difficulties encountered in urban geological exploration and monitoring, geological suitability evaluation for land space development, geological safety assessment for underground space development and utilization, 3D urban geological modeling and public services, and so on.