The natural reasons why the cities in Taiwan Province Province are mainly distributed in the west of Taiwan Province Province.

The western part is relatively flat, and the Han people come from the mainland relatively close, so the Han people who came to Taiwan Province for reclamation in the early years were mostly concentrated in the western part. It was only during the Japanese occupation that the emphasis was placed on the development of the east. For example, there are Japanese immigrant villages in Yilan and Hualien.

If there is no historical reason, the terrain in western Taiwan is relatively flat, which is conducive to reclamation and planting.