A GIS-based Approach to the Planning History of Utsunomiya, a Regional City in Japan: Zoning Transformation (1934–2022) and its Relationship with Urban Development

Urban shrinkage and population decline have increased the importance of understanding the long-term relationship between urban planning and urban development in regional cities. This study examines the transformation of land use districts in Utsunomiya City, Japan, from the initial zoning designation in 1934 to the present using a GIS-based historical analysis. Historical zoning maps from 1934, 1952, 1971, and 1984 were georeferenced and overlaid with the latest land use district data. To quantify zoning continuity, a new indicator, the Historical Zoning Consistency Index (HZCI), was defined as the proportion of areas that retained the same zoning category between successive planning periods. The zoning changes were then compared with major urban development projects, including industrial parks, land readjustment projects, as well as regional development plans.The results reveal contrasting patterns among zoning categories. Industrial districts exhibited the lowest HZCI values because of repeated policy shifts, including the transition from factory-location control to the recognition of existing industrial sites and the subsequent consolidation of industries into large suburban industrial parks. Residential districts showed the highest continuity, with expansion mainly occurring in suburban areas. Commercial districts experienced substantial changes only during the postwar reconstruction period, when all linear commercial districts disappeared, while commercial centers around railway stations remained stable. These findings demonstrate that the proposed HZCI provides a useful quantitative framework for evaluating the long-term continuity of land use districts and their relationship with urban development, while helping identify historical suburban hubs that can support “Compact Plus Network” policies in regional cities.