Why are most island cities in New Zealand located in the east?

First, New Zealand is located in the northwest trade wind zone in latitude, and the sea wind blows from the west all the year round, so the west coast is rough and rough, and it is not as easy to find a natural harbor as the east coast. Therefore, there are two ports, Auckland and Tauranga, as well as coastal cities such as Napier and Gisborne, on the east coast of North Island, while there is only one port, New Plymouth, in the west. Wellington, at the southernmost tip of the North Island, is located in the west, but it is located in a sheltered bay and still on the east coast.

Second, the tall and steep southern Alps run through the South Island along the west coast, which makes the land transportation between the west coast of the South Island and other areas very inconvenient. Therefore, there are only two ports established at the estuary of the river: Greymouth and Westport. The whole west coast of South Island is basically a national park and nature reserve. The eastern part of southern alps is generally flat, so there are important cities in Christchurch and Dunedin on the east coast, as well as some second-tier coastal cities such as Timaru and Omaru. Inver cargill, the third largest city at the southernmost tip of the South Island, is similar to Wellington.