This paper focuses on the time distance as an index of regional structure, and shows a new method for presenting its structure visually. The method enables us to create a graph of regional structure, which treats each city as a point, and related time distance between cities as the length of an edge. Since constructing the network from any time distance data is generally difficult, some rules are set for constructing the graph. Two types of visualized time-distance networks are designed in this paper. One is minimum time-distance network and the other is delaunay time-distance network. Visualized time-distance network has below good points. It does not contain errors in the figure, it is easy to understand, and it can also visualize additional informations in the figure. To show these methods, the author uses as examples the visualized time-distance networks in Japan and Europe. Moreover, a necessary condition for constructing the graph is also explored.

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This paper deals with a market in which consumers are continuously distributed on a network. Under this market, this paper proposes the Huff model on a network for estimating the demand of a store through the 'network distance space'. This model can estimate the demand exactly in terms of an explicit mathematical function, assuming that consumers are distributed uniformly on each link. With this demand function, a locational optimization problem of a retail store on a network is formulated and a method for solving this problem is shown.

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"Dezukuri", which used to be the main subsistent farming type in the Hakusan area, Ishikawa Prefecture, has rapidly disappeared during the 1950s and 1960s, due to the fuel revolution and the high ecomonic growth rate. At present, it is on the verge of the total extinction. In this paper, we analyzed the physical environment of the "Dezukuri" in Shiramine Village utilizing geographic information system (GIS) and remote sensing techniques. Based on the distribution map of the Dezukuris plotted at a s cale of 1:5, 000, in which 322 Dezukuris were identified with a total area of 1.39km2, we analyzed their location by superimposing the Dezukuri distribution map with maps of altitude, slope gradient, slope aspect, drainage systems, landslides, logging roads, geology, soil, vegetation, and the planting practice. Their preferred sites are found to be 600 to 900m in elevation, 15° to 20° in slope gradient, and the east aspect of the slope, in the areas of conglomerate-sandstone, brown forest soil and the white oak community.

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This paper discusses benefits and principles of using display agents for name placement as basic components of geographic maps. The display agents can decide their behavior depending on their circumstances. Display agents are important for applications of hypermedia systems to overlay incrementally pieces of graphic information as layers. Furthermore, display agents can realize concurrent work environments with less idling time for both users and computer systems.

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This paper deals with a questionnaire to urban planning section of local authorities in Japan. All local authorities having urban planning section answer this questionnaire. The result shows that it is more difficult to make digital maps and Geographic Information systems in cities with smaller population. On the contrary, it is easier for a cadastral survey in cities with smaller population. The area of city have only little effects on those items.

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GIS has an essential function for integration of geographic information. But the integration of geographic information from different systems is the most serious barrier in using the present GISs. This means that standardization is very important. Many standardization activities on geographic information are ongoing in the world. The most comprehensive one is ISO/TC211 activity. ISO/TC211 is related with other standardization activities such as OGC, CEN/287, ISO/TC204 and so on. ISO/TC211 scope covers all other standardization activities and it gives us frameworks and guide lines for specific standardization. Japanese standardization shall be based on adoption and adaptation of ISO/TC211.

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The Earth Resources Observation Systems (EROS) Data Center of the U.S. Geological Survey has been providing a 30arc second Digital Elevation Model (DEM) data set of the whole world (DCW DEM) through the Internet since 1995. Although the accuracy is one of the most important meta-information of the DEM data set, no such information has been provided by the data producer except for nominal accuracies of the original topographic maps. This paper summarizes a result of accuracy assessment of the part of the data covering Japan using existing higher accuracy DEM data sets developed by the Geographical Survey Institute (GSI). The assessment includes the investigation of the datum difference and the comparison between DCW DEM and GSI's DEM data. The calculated accuracy of DCW DEM is 89m RMSE. The datum investigation revealed that the datum of DCW DEM of Japan was Tokyo Datum instead of nominal WGS-84.

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Red-crowned cranes (Grus japonesis), once considered extinct, have been increasing in number in eastern Hokkaido, a northern island of Japan. One of the recent concerns about the cranes has been that the habitats in eastern Hokkaido may not be large enough to accommodate the increasing number of cranes. This study focuses on the breeding areas, especially the nesting sites of the cranes to develop a simple nesting site selection model using GIS so that the model will be used to help find suitable nesting areas in other parts of the island. Geographic features in 1:25, 000 scale maps and existing nest location points were digitized and a nesting site selection model developed for Kushiro Wetland with GIS. Potential nesting areas analyzed by applying this model are small and exist only along the edge of the wetland. The result is consistent with the understanding of experts on the cranes whose breeding environment is becoming undesirable. It is expected that GIS will be also useful for the subsequent analyses required to find suitable nesting areas other than eastern Hokkaido.

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An attempt was made to classify plant cover from a datafile developed by the Japan Environment Agency. This datafile has two kinds of information, codes of plant communities and the degree of influences of human activity on primeval vegetation in the center of a cell. A lookup-table for plant communities and corresponding plant cover types was constructed after alpha-numeric conversion of the plant community code and sorting. These plant cover codes in the table were applied to plant community codes in the above file, and a plant cover datafile was developed. To overlay the plant cover on other elements, precise spatial coordination of data sampling points was examined using two datafiles with different cell sizes, such as a 1km interval for the plant cover and a 250m grid system for a digital terrain model (DEM) in which altitudes above sea level were sampled at 250m intervals. This study confirmed that the plant cover derived from the above datafile is sufficiently useful for ground truth in satellite remote sensing, and for careful overlaying of other environmental elements.

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