Land use/cover changes in Japan: from the past to the future

Land use in Japan for c. 1900, 1950 and 1985 has been reconstructed, based on the 1:50 000 topographic maps for these periods, and digitized. These data sets have then been used for the analyses of land use/cover changes, model simulations and checking of the models. This paper outlines how the data sets have been used and what has been found regarding the land use/cover changes in Japan over the last hundred years, and presents the frameworks and results of empirical models of the changes. Two similar, but different, approaches have been taken in order to obtain a likely land use pattern for the 2020s. The first is based on a simple but realistic assumption that the ‘2 km grid squares’ where ‘settlement’ is the second largest type of land use will be predominated by ‘settlement’ in about 35 years. This assumption has been justified by comparison of the data for c. 1950 and 1985. In fact, the validity of the model has been tested, and proved to be highly relevant. Another model assumes that settlement expansion occurs so as to ease high population density in settlements, and that it affects other types of land use. A general land use map for the 2020s has been produced based on these and other assumptions. The distribution of urbanized areas resembles that obtained by the first model. It is noted that paddy-field is the largest type of land use that suffers from urban expansion in the coming two to three decades in central Japan.