Ecosystem Restoration and Water Source Purification (Terraced Rice Paddies, February 2003)

Ecosystem Restoration and Water Source Purification (Terraced Rice Paddies, February 2003)

Terraced rice paddies are terraced rice paddies located in mountainous areas, etc., which once played an important role in Japan's agriculture and ecosystem. Due to their characteristics, terraced rice paddies have an extremely high water retention capacity. Even if there is precipitation, the water does not run off immediately, but slowly percolates underground, thus having a water source recharge capacity equivalent to that of a dam. For this reason, they have contributed greatly to water resource management and flood prevention in the region. However, in recent years, due to the decline in the farming population, urbanization, and mechanization, it has become difficult to maintain and manage terraced rice paddies, and many of them are being abandoned.

Importance of Preserving Rice Terraces
Abandoned terraced rice paddies are overgrown with vegetation and water does not flow properly, which reduces the soil conservation function and can cause flooding and landslides. Furthermore, the loss of terraced rice paddies reduces the water source recharge function, leading to water shortages in downstream areas and worsening river water quality. In response, there is a need to conserve and restore terraced rice paddies.

Contribution to water source purification
By allowing water to slowly percolate into the soil, terraced rice paddies naturally remove pollutants and contribute to the purification of groundwater and rivers. In particular, pesticides and chemical fertilizers used in agriculture can contaminate rivers and groundwater if not properly managed, but structures such as terraced rice paddies can act as natural filters and prevent these harmful substances from leaking out.

Restoration Efforts
In recent years, ecotourism and community development activities have been promoted using terraced rice paddies, with local residents and government, as well as businesses and NPOs, working together to restore the terraced rice paddies. This is expected to not only support agriculture, but also contribute to the restoration of the ecosystem and local water resource management. In particular, the use of terraced rice paddies restores the biodiversity of the region and balances the environment and the economy.