**Abstract**

Based on the history of urban form and the history of disasters, and the current issues in Japanese society such as depopulation and expansion of the cities in the areas with high disaster risk, the formation of a compact city with safety to natural disasters is required. To realize the sustainable cities mentioned above, the necessity for plans and activities to (1) induce residents from areas with high disaster risk to safer areas with long-standing perspectives, (2) to improve the safety of areas that promote induce residence and increase population density, and the areas with the difficulty of induce residents are explained. As one of the means to support such plans and activities, the importance of the development and utilization of planning support tools was shown. Especially, through some examples, it showed the usefulness for substantiating discussions and considering safe and sustainable urban structures.

**Keywords:** urban planning, depopulation, natural disaster risk, compact city, planning support system, Japan
