Geohistory - Terrain
The Dōzen Islands with their mountainous caldera terrain lack wide, flat land suitable for rice paddies. Because of this, the unique rotation farming called makihata was developed and flourished on the islands. However, the northern part of Nakanoshima Island is home to the the only wide plain in the Dōzen Islands, where rice is grown commercially. Rice farming in Ama Town (Nakanoshima Island) is supported by an abundance of spring water, but it also would not be possible without the volcanic activity that occurred here long ago.
The area where the Amagata Plain lies now was actually a deep inlet when Dōzen was first formed. Later, when volcanic activity occurred about 2.8 million years ago where the Akiya Coast lies today, the lava that erupted closed off the mouth of the inlet. Soil and sand then accumulated inside, creating an area of reclaimed land.
