Drivers of land-use change: the roles of urban planning boundaries and population concentration areas in Japan over 45 years

Understanding the spatial factors influencing land-use transitions is essential for sustainable land management. This study analyzed nationwide land-use change in Japan over 45 years using 100 m governmental land-use grids, examining the effects of institutional zoning and pre-existing land-use patterns. A comparison of 1976 and 2021 land use revealed that 76.4% of grids exhibited no change, 5.5% experienced urbanization, 4.8% were newly cultivated, 4.5% were abandoned; 1.2% underwent crop conversion, 2.1% experienced vegetation succession, 2.0% were affected by residential relocation, 1.7% involved the creation of new water bodies, 0.9% reflected waterway stabilization, and 0.8% fell into other categories. Among unchanged grids, forests accounted for 59.6%; water bodies, 29.7%; urban land, 3.1%; farmland and paddy fields, 7.1%; and wastelands, 0.4%. Urban planning boundaries effectively mitigated uncontrolled sprawl, However, farmland abandonment occurred more frequently within designated urban planning zones. In contrast, conservation areas were effective in maintaining both farmland and forest land uses. Proximity to DIDs accelerated both urban and non-urban transitions—including farmland abandonment and new cultivation—indicating that the 500–2,000 m range from DIDs constitutes the primary sprawl zone. In this zone, land-use dynamics appear to be shaped more by demographic proximity than by regulatory control. These findings highlight how planning frameworks and population distribution jointly determine land-use trajectories, providing an empirical basis foundation for refining land-use policies that balance urban containment, farmland and forest conservation, and sustainable land management amid demographic decline.