Little information has been made available on the accuracies of the Digital Map Series data sets published by the Geographical Survey Institute (GSI) . Nevertheless, provision of this meta-knowledge is important to enhance a users understanding of the results derived from spatial analysis. This paper estimates the accuracies of the Digital Map Series data sets. The estimated root mean square errors of; Digital Map 25000; Digital Map 10000; Digital Elevation Model (DEM) 50m; DEM 250m and DEM 1km; are less than, 18.5m, 7.4m, 7.2m, 50m, and 50m on the ground, respectively.

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The usefulness of computer graphics as a means of simulating changes in landscape caused by stone quarrying was examined. Montage and perspective projections were used to depict the color and other features of the surface of mountains, the course of tree planting on the pit face and the features of a newly developed pit face. A wireframe model was used to predict changes in the geographical features of quarries on the basis of existing stone-quarrying plants. By combining these techniques, we devised a method for editing two-dimensional still pictures, obtained from video tapes, from various angles, i.e., by up to 30 degrees and the angle of elevation by up to about 10 degrees. Still images of the current scene and the predicted future scene were made while gradually changing the angle of view. These pictures were linked to each other to yield an animation which represents the expected changes in the scene as viewed from a car moving past the front of the quarry.
This simulation method allowed us to estimate changes in the scene in advance, and was found to be quite useful in obtaining basic data concerning future changes in the scene which could be caused by stone quarrying.

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An attempt to make a computerized solid model of geologic system is introduced. This paper describes that computer graphics of solid models is a great help to understand complex geologic structures correctly.
An actual geologic structure studied by geologists is used as an example model. The model covers 18km×25km area and 5km in depth. More than ten complex faults and eleven types of rock are included in the model.
This paper also describes, necessary input data for the modeling, which are topographical data of ground surface, geologic maps at several sections, and attribute relation data which provides mutual relations of the sections. The kriging algorithm is used for modeling surface boundaries of subterranean layers. A solid modeling software in market was used in this study and the process of creating the geological solid model with the software is also presented.

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The study is to simulate a straight channel of the Arkansas river around Tulsa, Oklahoma, USA, which channel underwent massive erosion and channel migration as it returned to a more natural, meandering path. Experiments have done by modeling the sedimentary processes that changed in response to changing hydraulic and geologic parameters resulting from the excavation of the channel. Geologic parameters such as fluid and sediment discharge, velocity, transport capacity, and sediment load are input into the model. These parameters regulate the frequency distribution and sizes of sediment grains that are eroded, transported and deposited. The experiments compare favourably with aerial photographs, recreating similar patterns of fluid flow and sedimentation. Comparisons reveal a substantial degree of concordance between actual and simulated channels. It is to help validate the simulation procedure's general applicability for experiments involving flow and sediment transport by rivers. Moreover, simulations provide insight for understanding and spatial distribution of sediment bodies in fluvial deposits and the internal sedimentary structure of fluvial reservoirs. This simulation model can be contributed to support the development of the new design criteria compatible with natural river processes including flood, especially drainage problem to minimize environmental disruption.

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