The continued development of GIS requires that spatial data be edited reliably. However, methods to manage the quality of spatial data during updates have not been established, the result being that effort put into the update is not connected to an overall improvement in data quality. Recognizing this problem, a method of evaluating the quality of specific cases is researched, and a tool developed for practical use. While the quality evaluation of the update process involves two steps, the sampling of the update results and the quality evaluation of those results, this research implements a practical method of prioritizing the first of these steps, then categorizing patterns in the differences before and after the update, and presenting the results of the difference sampling with an assigned ID. The tool developed for this research was used on the results of data updated in a local government project, and it was determined that the quality did not achieve the quality requested by the contractor, and that the results of this research could contribute to the overall quality of spatial data as it is updated.

To manage water resources effectively at a local level, decision makers need to understand how climate change and human activity may impact local streamflow as a precious natural source of water use. However, the impact is often not well studied with locally obtained data such as monitored flow. This paper presents an integrated approach to study potential impact of precipitation and land-cover change on local streamflow over the next decades. The study area is the Srepok River basin, a tributary sub-basin of the Mekong River. A hydrological model was developed in the Hydrologic Modeling System (HEC-HMS) environment and calibrated using local precipitation and streamflow data. Several scenarios were developed considering climate change and socio-economic development in a GIS environment, and streamflow in 2025 and 2050 was estimated for each scenario. The paper ends with discussion on possible adaptations for a given area.

Recent research in the U.S., Europe, and Australia has consistently identified that the risk of victimization is temporally elevated in areas where crimes have occurred in the recent past. The phenomenon, termed near repeat victimization, has caught limited attention among criminologists in Japan, where crime rates are drastically lower than in most western countries. The present study conducted a spatio-temporal analysis of crimes using data on crimes reported to the police in order to identify near repeat victimizations across five crime types (violent offenses, purse-snatching, theft from vehicles, business burglary, and residential burglary). The results have confirmed the risk of near repeat victimization for all crime types, except for violent offenses. The paper concludes with a discussion of implications of the findings for both criminological theories and crime prevention activities by the police.

How influential and effective GIS could be in the society was actively discussed in English-speaking countries through the 1990s. Noticing potentials in “Public Participation GIS (PPGIS),” many conducted research. This study reviews research trends and practices related to “GIS and the Society,” promoted in English-speaking countries, and discusses its possible directions in the future. One noticeable trend is that, due to rapidly advancing information-communication technology and its global-scale availability, now citizens can participate in more diverse ways, using the web technology. Taking this trend into discussion shall lead to further development of PPGIS research, from which the sites of citizen’s participation will hopefully benefit.

Topological relations, which concern how two spatial objects intersect with each other, are one of the most well-studied types of spatial relations in GIScience. This paper gives an overview of the research on topological relations, especially reporting recent breakthroughs after the introduction of the 9⁺-intersection. First, we introduce three models of topological relations (9-intersection, 9⁺-intersection, and RCC) and explain how to identify the sets of topological relations between two objects of various types. Then, we explain basic ideas of two relevant inventions: (i) conceptual neighborhood graphs, which schematize a given set of topological relations, and (ii) qualitative spatial calculi, with which we can realize the disambiguation of the topological relations between multiple objects in the same space. Finally, we discuss future research issues and applications of topological relations.

According to the Building Standards Law, lots have to be basically adjacent to a road whose width is equal to or more than 4 meters. Due to spatial data limitation, it is impossible to judge if a lot is adjacent to a road defined above by using Geographical Information Systems (GIS) in general. Meanwhile, there are many spatial data of buildings available. The principal, that each building is basically built on a lot, potentially enables us to judge indirectly if a lot is adjacent to a road. There are mainly two methods to do this: the method using buffer polygons and the method using Voronoi segmentations. The accuracy of these methods to judge adjacency of a lot to a road is examined. It is shown that the difference of the degree of accuracy between them is from 0.2% to 3.3%, implying that the method using buffer polygon is a practical substitution for the method using Voronoi segmentation in view of time required.

Bamboo groves have formed the beautiful landscape as the essential element for the Japanese scenery since long ago, and have been maintained and managed as the landscape resources. Especially in Kyoto, the green given by bamboo groves have played an important part in making a lovely effect on the landscape of temples and shrines. They have been the landscape resources, and have been the resources of tourism as well. The authors intend to clarify how the maintained and managed bamboo groves affect the landscape in Arashiyama-Sagano district, the famous tourist area in Kyoto. They are approaching the landscape of bamboo groves with analysis from both the broad and detailed point of view by using the geo-information technology.

Multipath is one of the main causes of degraded position accuracy in the Global Navigation Satellite System (GNSS) because portions of the signals can be reflected by high buildings in dense urban areas. Multipath mitigation techniques based on hardware enhancement or signal processing help to improve GNSS accuracy for high-precision surveying. Geographic Information System (GIS) is also used in the signal propagation model to predict multipath effects. In addition to these existing approaches, we found that spatial statistical methods are useful in multipath mitigation because a unique spatial distribution of user positions can be produced by the multipath. In this paper, we present a spatial statistical method for mitigating multipath and improving the accuracy in GNSS positioning. Multipath tends to be associated with spatial outliers in simulated user positions (SUPs) and contributes little to the spatial clustering of SUPs. Using these spatial characteristics, we developed a method for identifying multipath satellites, which consists of the components of deviation distance, deviation load, and deviation ratio. Once the identified multipath satellites are excluded, a user position is determined using a mean spatial center of the SUPs from the remaining satellites. The effects of such multipath mitigation were validated by examining whether our method correctly identified multipath satellites and by comparing the position errors with and without the method. We demonstrated the applicability of our solution with a simulation experiment for Shinjuku, using a precise ephemeris for the Global Positioning System (GPS) and the orbital parameters for the proposed constellations of the GALILEO and the Quasi-Zenith Satellite System (QZSS).

This paper examined routine activities of elementary school children using GPS. Sixty students aged 7-8 and 10-11 in one elementary school participated in the experiment to track their after-school trips for 14 days. Questionnaire were concurrently filled by parents to ask destinations and companions of children’s trip. Individual trips other than group-home-to-trips (such as going to/from playground, visiting friends, attending private tutoring) were twice as long as school-home trips that much crime prevention efforts were currently paid. The frequency and length of the individual trips were examined by grade of subject, type of destination and companion. Routine activity theory was introduced to discuss policy implications in applying tracking technologies in safety of children.