The present paper reviews educational activities of the Japan Society of Geoinformatics through symposiums and workshops. In the first decade, after the Society was established in 1990, the Society worked to develop an understanding of computer processing of geological information. In the next decade, the Society tried to foster talents who can use computer resources efficiently in field surveys. The Society planned to establish a qualification system, of which implementation was postponed as premature. The Japan Geotechnical Consultants Association established the qualifications system of Geological Information Manager in 2006. The Society has cooperated on the operation of the qualification system from the planning stage. In the recent decade, the computer processing of geological information has faced a new phase of practice and verification and the major concern has been shifted to analysis systems for practical use such as Web-GIS, utilization of bore-hole databases and 3-D geologic modeling. To meet the social demands, it is necessary to incorporate Geoinformatics-oriented courses in curriculums at universities. Advanced curriculums of Osaka City University and Okayama University of Science are reviewed briefly as case studies. The Society will continue to play a central role in development of human resources who advance a wide variety of computerization in geological works.

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“Geology-Oriented Logical System” (GEO-LOGICS) is a new research branch of geology proposed by Wadatsumi et al. (1987) to construct a logical system of geology in a mathematical form as theoretical bases for geological data processing. The present paper reviews the results of research during 30 years since Japan Society of Geoinformatics was established in 1990. Continuous space and time are frequently divided into geologic units and geologic time spans respectively and a wide variety of relations between discrete objects are major research targets in geology. From this point of view, new theories and algorithms have been developed mainly based on Discrete Mathematics. Major results are: (1) three axions that formulate fundamental properties of sedimentary strata also known as the law of original horizontality, the law of lateral continuity and the law of superposition, (2) a labeled directed graph that represents contact relations of geologic units exposed at an outcrop, (3) a flow chert of data processing to derive the regional stratigraphy from observation data at many outcrops, (4) a simple mathematical model that simulates fundamental procedures of biostratigraphy, (5) a logical relation between geologic units and surfaces, named the logical model of geologic structure, which defines a 3D geologic structure mathematically, (6) a labeled binary tree that represents the logical model of geologic structure and (7) a bitwise operation method to perform a variety of set operations of subspaces defined by the logical model. Further development of GEO-LOGICS is desirable to promote a wide variety of geological data processing

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The three-dimensional (3D) geological model is one of the end-product of geological information generated as a result of analysis based on the fundamental field data and the knowledge/interpretation of the geologist. In Japan Society of Geoinformatics, many research papers related to the construction of 3D geological model have been reported since the formation of the Japanese Society for Geological Data Processing (the predecessor of this society) in 1979. In this paper, the 3D geological model construction/visualization and the geological boundary surface estimation have mainly been described, which have been mainly discussed in the Japan Society of Geoinformatics. The results of these researches were presented and updated with improvements and enhancements keeping pace with the evolution of computers over the years since inception of the Japanese Society for Geological Data Processing. The basic mathematical principle for the model construction was formulated by around 2000. In the following decade, development of algorithms as standalone packages and integration into general-purpose GIS for 3D geological modeling were completed. Subsequently, the research and development focused on promoting practical use and wider dissemination. Over the period of time, more robust algorithms for estimation of geological boundary surface has also been advanced. Presently, several of the research outcomes have provided technical basis for commercial 3D geological modeling software that have been developed and used in practical business. Finally, the current status and future prospect of the 3D geological modeling is described from the viewpoints of model creators and users.

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In any geoscience survey, each survey technique must be effectively applied, and many techniques are often combined optimally. An important task is to get necessary and sufficient information to meet the requirement of the survey. A prize-penalty function quantifies effectiveness of the survey, and hence can be used to determine the best survey technique. For example, when the function is applied to classification of alteration types in a gold mineralization area, it suggests that a chemical technique is advantageous compared with a mineralogical technique based on XRD in the case that penalty defined as the refund for prize is low, and that the accuracy of the classification is high. On the other hand, information-cost function can be used to determine the optimal combination of survey techniques on the basis of geoinformation obtained. To realize the optimal alteration between techniques, however, it is necessary for us to able to evaluate obtained geoinformation. Entropy and variance have a possibility for the evaluation of geoinformation as shown in a simple model where both variables decrease with progressing geological survey.

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Geologic-related data are basically point data, which are distributed sparsely and irregularly with limited number as compared to the size of target area. Regional imaging of the Earth interior with high accuracy such as geologic structure, physical and chemical properties, ore grade, configuration of petroleum and geothermal reservoirs are required in Earth science and engineering fields. Accordingly, spatial modeling for reconstructing correctly the true distribution from the irregularly-spaced point data has been more and more important. This paper classifies spatial modeling techniques into spline-based, geostatistics, and artificial neural network-based types and reviews shortly their principles and recent examples of developments and applications. The examples focus on improvement of estimation accuracy using supplementary information, applicability extension to vector data such as fracture and category data indispensable to lithofacies distribution, multiscale modeling and decomposition into different scales, application of covariance function to Bayesian-based inverse problem, spatio-temporal multivariate modeling, and extension from two-point to multiple-point statistics. The techniques suitable to these examples are summarized and their usefulnesses are demonstrated through new Earth scientific and engineering findings obtained by spatial modeling. Essential issues for the next step are spatial modeling by a combination of physical and chemical laws, geologic process, and geostatistics; application to largescale dataset and global area and; deepening of consideration of multiscale and heterogeneous structures. In addition, preliminary results and trial ideas concerning these issues are presented.

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The database architected by the authors has been used to establish the geological model and to analyze the mechanical behaviors of ground from the geotechnical engineering viewpoint. It is the distinguished feature for the proposed database that the “observation articles” in the boring log are taken account of, which makes the prompt search of geoinformation to identify the sedimentary environment of strata easy. Furthermore, the authors have architected a prototype to manage the ground meshes of geoinformation, which means to be the secondary use of geoinformation registered in the database in this paper. By using the secondary geoinformation, it may be considered to be easy to collect the geoinformation possessed by the private organizations. As a result, it is considered that the proposed database contributes to improve the accuracy of 3D model of ground.

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