Using the empirical road network data and regression analysis, we investigated the ratio of the road distance to the straight line distance in major cities in Japan. The ratios are relatively different by cities. Therefore, in order to replace the road distance by the straight line distance, we do not use the known ratio that is revealed in different city without careful consideration. If we replace the road distance by the straight line distance, we have to consider the road network of the target city. In addition, we found that the cities which have small ratio of the road distance to the straight line distance generally tend to have high coefficient of determination. In other hands, the cities that have high ratio of the road distance to the straight line distance generally tend to have small coefficient of determination. Therefore, when we replace the road distance by the straight line distance in the cities which have small ratio of the road distance to the straight line distance, there is a certain degree of reliability.

We analyze and evaluate a correlation of total coliform and building data on a monthly basis in the basin of Oita and Ono River. In addition, we analyze and evaluate an optimal range to use the building data from the total coliform's observation points, and the optimal attributes (number, area, total floor area) of building data. As a result of the analysis, we found that the correlation of total coliform of June and building data is high, and the correlation is high in the case of using the building data of about 7km radius and the total floor area.

Flood hazard maps are quite useful for the aid to damage reduction and emergency operations for major flood crisis. In this paper, in order to derive flood hazard maps even for ungauged basins, we propose a simple method for assessing the flood inundation area based on purely topographical analyses of Digital Elevation Model (DEM), without meteorological data and hydrological models. The quality of the map derived from the proposed method is evaluated for the Fujikawa river basin against the corresponding maps given by Ministry of Land, Infrastructure, Transport and Tourism. Despite the crudeness of the model, the simulated maps are in good agreement with the reference maps. For the Chao Phraya River basin in Thailand, where an unprecedented flood disaster was caused during the 2011 monsoonal season, the simulated flood inundation map successfully reproduces the actual flooded land.

This paper proposes a cost estimation sheet supporting decision making for city planning. The urban form is represented by 30 by 30 cells on the sheet and the cost is estimated regarding population distribution, population projection, maintenance cost of road network, water supply and sewerage network, and investment for new development site. The sheet first requests its user to input current population distribution and several cost parameters. Then the sheet designates the downtown cells. A distance from closest downtown cell is calculated for each cell, which is used for cost estimation. User will be asked to finalize the spatial plan where cells are given the following labels; downtown, to be developed as new sub centers, to be disengaged. The maintenance cost is calculated by number of cells, distance from closest downtown, and population within the cell. Finally, the sheet gives how long does it take until the saving of maintenance cost by disengagement will balance the development cost of new sub centers.

We formulate a model in which the direction angle influences the ratio of road distance on a rectangular grid network to the Euclidean distance between the endpoints. We used trigonometric regression analysis to test the null hypothesis using an F-test and estimated the parameters of the model in each quadrant around railroad stations in the Tokyo Metropolitan Area. The F-tests show the significance of the model in many regions. The direction angle and the parameters for each region enable the estimation of each road distance from the Euclidean distance between the endpoints.

This study investigates the status and issues involved in the use of geographic information systems and science (GIS) in economics. Although economics does not employ GIS as much as environmental sciences and geography do, it uses GIS more than other social sciences do, and increasingly so in the recent years. Graduate students who learn to use GIS for economic analysis recognize both the usefulness of GIS and the difficulty of GIS and data handling. Results from questionnaire surveys suggest that economists have difficulties in obtaining expensive data, and they have few opportunities to learn GIS. Developing GIS education opportunities and curricula, improving GIS educational materials, and expanding knowledge about spatial data availability are expected to advance GIS education and research in economics.