Agricultural land at river confluences reduces flood risks

Tokyo, Japan (SPX) Dec 09, 2024
Researchers from Tokyo Metropolitan University have demonstrated that agricultural land near river confluences can significantly reduce flood risks. Their study highlights the benefits of Eco-DRR (Disaster Risk Reduction), a method leveraging environmental resources to enhance flood resilience. A statistical analysis revealed that municipalities with farmland in areas with high water storage capacity experienced fewer floods, with the impact being most pronounced near river confluences. These findings could inform strategic land use planning.

With climate change increasing the likelihood of extreme weather events, flood prevention has become an urgent priority for local authorities. While conventional methods like dams and barriers play a role, they have ecological drawbacks and physical limits. Eco-DRR offers a sustainable alternative, using resources like agricultural land to absorb and temporarily store floodwaters, reducing damage.

Associate Professor Takeshi Osawa of Tokyo Metropolitan University leads research on the role of Eco-DRR in Japan, a country with challenging mountainous terrain. Urbanization and rural depopulation have led to abandoned farmland, making it crucial to evaluate the impact of agricultural land on flood risks.

Osawa's analysis spanned 1,917 Japanese municipalities, examining flood data from 2010 to 2018 and focusing on the presence of farmland in areas with high water storage capacity. Results showed a clear link between such farmland and reduced flood risk, with a stronger correlation when agricultural land was located at river confluences. These points, which are biologically rich and critical for biodiversity, present an opportunity to align food security, disaster mitigation, and ecological preservation.

This research was funded by the Environmental Restoration and Conservation Agency of Japan's Environment Research and Technology Development Fund (JPMEERF20222G01) and the Water Resources Environment Center of Japan.

Research Report:Agricultural land around river confluences could strongly suppress floods occurrences