Potential of mitigating floodwater damage to residential areas using paddy fields in water storage zones

Abstract

Natural disturbances, which are important events that are inherent in any ecosystem, can cause disasters to human society. To address these, ecosystem-based disaster risk reduction (Eco-DRR) is investigated as a future infrastructure because of its lower cost of implementation and maintenance as well as its provision of different additional ecosystem services. Studies have proposed at least two types of Eco-DRR functions: inhibition, which reduces the potential occurrence of hazards, and mitigation, which reduces a hazard's damage in its aftermath. This study evaluated the latter type for paddy fields in the inland regions of central Japan. Using separate long-term statistical records of urban and agricultural inundated areas, we tested the relations between these areas and their land-use conditions. We predicted that paddy fields having a large area and that are low-lying are effective for flood mitigation. The results showed that local areas with paddy fields that potentially store large amounts of surface water, namely, latter pattern namely low-lying paddy fields, tend to reduce urban area inundation. Interestingly, the total paddy field area did not reduce inundation; nevertheless, the condition of the paddy field location is essential. This result suggests that such specifically located paddy fields could effectively lessen residential area inundation. This type of seminatural land-use could be used as a green infrastructure (GI) for Eco-DRR.