In 1968, in Japan, Area Division System (ADS) of the city planning act was established to prevent unregulated urbanization. The ADS divides city planning areas into urbanization promotion areas which prevent unregulated urbanization, and urbanization control areas which promote planned urbanization. The system achieved good result when the population was growing. However, in local cities, applying the system has been one of the factors that interfere with the activation of the city when population declines. In 2000, the city planning act was revised, the ADS became selectivity by the local government. By abolishing ADS, there are local governments who can control land use in accordance with the actual situation of each region. In this study, we target of the prefectural capital abolishing the ADS in 2004, as a case study. We aim to clarify the impact and factor of abolishing the ADS, and to consider the land use trend in the case abolishing the ADS. At first, we analyze urban structure by developments and farmland conversions. Next, we make a 250 meter mesh, and analyze the factors that influence farmland conversion by quantification theory. Moreover, we calculate the predictive value of farmland conversion using category-score of quantification theory. At last, we simulate abolishing the ADS of the city that operate the ADS.
The results are as follows.
(1) The result of comparing the number of farmland conversions before and after abolishing the ADS, farmland conversion increase outside of use district.
(2) Before abolishing the ADS, “use district”, “distance to government offices”, and “population” have an influence on farmland conversion. After abolishing the ADS, the number of mesh with predictive value over 4.5 decreases, and the over 3.0 widely disperse inside or outside the use district.
(3) As a result of forming the development potential map, we point out that farmland conversion increased in near the use district.
