Nurume (waterway for heating water)

In rice paddies located in mountainous areas, farmers take measures to keep the water temperature high to avoid the negative impact that a low water temperature can have on rice growth.
A nurume is a system used to increase the water temperature by extending the length of the waterway so the water is heated by solar energy while running down it. There are several ways to apply this method such as by setting up a circular waterway around the rice paddy or building a pond just in front of the rice paddy. The term nurume is short for nukumeru or nurumeru, meaning “to warm.”