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Rice terraces are paddy fields made on sloping land that follow the natural contour lines, suited to the Japanese landscape. The terraces blend in with the natural scenery and give viewers a great sense of peace and comfort. Rice terraces are also growing into a focus of agro tourism. However, farming on these rice terraces has low labor productivity, and with the advancing age of the farmers in the mountainous areas, it has become difficult for them to continue farming on the rice terraces. Their abandonment is now noticeable. For this research, one city sustaining the rice terraces viz. Tokamachi City in Niigata Prefecture, was selected as the study area. We investigated how the topographic factors (altitude and slope) limit land-use and land-use change focusing on land-use in 2006 and land-use change between 1987 and 2006 using Geographic Information System (GIS). It was shown that topographic factors directly limit the land-use. Land-use change in Tokamachi City between 1987 and 2006 was significant in paddy fields. Paddy field area decreased significantly at high altitude on steep slopes. On the one hand, paddy field located at low altitude on a gentle slope mostly changed to buildings and roads. On the other hand, paddy fields located at high altitude on steep slopes changed to abandoned farmland fields and forestry. Specifically, paddy fields located at high altitude of more than 200m and on slopes steeper than 5deg have tendency to change to abandoned farmland fields and forestry, even though not a few paddy fields located at high altitudes on steep slope continued to be maintained as paddy fields. Furthermore, 20-60% of rice terrace fields on slopes steeper than 5deg were converted into other land-use. It was suggested that the topographic factor of angle of inclination is strongly limiting to the landuse as rice terraces.
