地形及び地質調査で得られるデータには，種類と程度の異なる複数の不確実性が含まれる．このため，それらデーを利用し構築される地形・地質発達史には，使用データに起因する不確実性が必然的に含まれることとなり，デーの不確実性の評価が重要となる．本研究では，地形・地質発達史の復元における主要な入力データである隆起速の算出結果について，階層分析手法の一つであるEvidential Support Logicを北海道北部の幌延地域における複数の査事例に適用し，不確実性の発生要因やデータの不確実性の程度を分析した．その結果，隆起速度の算出結果に確実性をもたらす調査項目を特定し，不確実性の程度を定量的に示すことができた．今後，ESLの分析結果を踏えた調査項目の設定とデータ品質管理手法を地質環境調査の体系へ組み込むことにより，要求品質に見合う調査ータを効率的に取得できると考えられる．

: An expert in a geoscience handles and analyzes the multidisciplinary and huge amounts of geo-environmental data by applying of his/her technical knowledge gained through the long years of experience in the field of a geoscientific investigation. The technical knowledge, especially technical know-hows and decision-making process, play the key role on this occasion but it is almost implicit ( tacit knowledge ) and cannot be easily documented. To promote the effective use and passing of the knowledge down the generations, the knowledge has to be externalized in a user-friendly form. In this study, decision-making process and technical know-how on an estimation of uplift rate by using a marine terrace have been clarified by the application of a knowledge engineering approach. Investigations and analyses for the estimation of uplift rate are classified into 8 units of "task". A sequence of the task from "extraction of pre-existing information" to "calculation of uplift rate" has been illustrated as a "task flow". The decision-making processes in each task have been illustrated as an "IF-THEN rule-base" and a "flow diagram of decision-making process". The rule-base and diagram show input for the decision-making, decision point conducted the decision-making, and task and output resulting from the decision-making. To share and pass this externalized tacit knowledge down the generations it is important to integrate the knowledge into the IT-based "Expert System" and continuous improvement of the knowledge incorporated into the system.

The investigation methods for characterizing natural events and processes in a coastal field have been extracted on the basis of analysis of previous research. Collected information is classified into three groups according to the characteristics of natural events/processes and investigation methods. First group is the methods for evaluation of uplift, subsidence and sedimentation rates. Second group is the methods for evaluation of denudation rates. The third group is the methods for reconstruction of the climatic and sea-level changes. Study area, timeframe of the investigation, work sequences, techniques for age-determination, index and objects for characterizing natural events/processes, etc. in each research example were arranged in an 'information spread sheet'. Information on applicability of the each investigation method was extracted from information spread sheet, and was arranged in tabular form. Based on an analysis of the above information, investigation method that can be applied to a coastal region was extracted. The methods and indices are as follows: Uplift rate: the heights of marine terraces are the most important index in an upheaval region. Subsidence and sedimentation rate: the depths of strata underlying an alluvial plain are main indices in a subsidence region. Denudation rate: the features of marine terrace are main indices and the inspection of denudation processes by the use of a numerical simulation is necessary. Climate change: lacustrine deposits are main object for investigation. Sea-level change: reconstruction of relative sea-level change curve including uplift/subsidence factor and paleogeography based on acoustic exploration and the investigation of marine terraces. (author)

Geological hazard assessments are being used to make important decisions relevant to nuclear facilities such as a repository for deep geological disposal of high-level radioactive waste. With respect to such repositories, topographic evolution is a key issue for description of the long-term evolution of a groundwater flow characteristics in time spans of tens to hundreds of thousands of years. The construction of topographic evolution models is complex, involving tacit knowledge and working processes. Therefore, it is important to externalise, that is to explicitly present the tacit knowledge and decision-making processes used by experts in the model building unambiguously, with thorough documentation and to provide key knowledge to support planning and implementation of investigations. In this study, documentation of the technical know-how used for the construction of a topographic evolution model is demonstrated. The process followed in the construction of the model is illustrated using task-flow logic diagrams; the process involves four main tasks with several subtasks. The task-flow followed for an investigation to estimate uplift rates linked to the task-flow for the modelling of topographic evolution is also illustrated. In addition, the decision-making processes in the investigation are expressed in logical IF-THEN format for each task. Based on the documented technical know-how, an IT-based Expert System was constructed. In future work, it is necessary to analyse the knowledge, including the management of uncertainties in the modelling and investigations, and to integrate fundamental ideas for managing uncertainties with expert system.