Japan's Mass Wasting Hazards

Japan's mountainous terrain makes the country highly prone to mass wasting hazards. With over 70% of its land covered by mountains and hills, Japan experiences frequent landslides, debris flows, and rockfalls, especially during the rainy season, typhoon events, and after earthquakes. The combination of steep slopes, heavy rainfall, and frequent seismic activity creates a perfect storm for these destructive events. To mitigate the impact of mass wasting and protect its population, Japan has developed a sophisticated system of prevention, monitoring, and early warning.

Hiroshima Landslides

In August 2014, heavy rainfall triggered multiple landslides in Hiroshima, killing 74 people and destroying hundreds of homes. This tragedy prompted the Japanese government to enhance its early warning systems and refine its risk assessment methods. Today, Hiroshima has an upgraded landslide prediction system that combines AI technology with real-time weather data, offering faster and more accurate warnings.

Japan’s Prevention and Mitigation Efforts 

1. Sabo (Erosion Control) Engineering: Japan has implemented sabo engineering—a system of erosion and sediment control that includes the construction of check dams, retaining walls, and drainage channels. These structures slow down the movement of debris and prevent large-scale landslides. 

2. Early Warning and Monitoring Systems: Japan has one of the most advanced early warning systems in the world, combining meteorological data, geotechnical monitoring, and artificial intelligence to predict and alert residents of potential hazards. Landslide Early Warning System: The Japan Meteorological Agency (JMA) uses real-time rainfall data, soil moisture conditions, and slope stability models to issue landslide warnings. These alerts are broadcast through TV, radio, and mobile apps. Seismic Monitoring: Japan’s extensive network of seismometers detects earthquakes and assesses their potential to trigger mass wasting events.

3. LIDAR and Remote Sensing Technology To assess vulnerable areas, Japan uses LIDAR (Light Detection and Ranging) technology to create detailed topographical maps. These maps identify unstable slopes and high-risk zones, helping authorities prioritize protective measures. 

4. Community-Based Disaster Preparedness Japan emphasizes community involvement in disaster preparedness. Local governments conduct regular evacuation drills, distribute hazard maps, and educate residents on how to respond during emergencies. 

Sources

Climate Adaptation Platform. “Landslide and Disaster Preparedness in Japan.” Climate Adaptation Platform, 17 Nov. 2022, climateadaptationplatform.com/landslide-and-disaster-preparedness-in-japan/.

Konagai, Kazuo. “More than Just Technology for Landslide Disaster Mitigation: Signatories to the Kyoto Landslide Commitment 2020-No. 1.” Landslides, U.S. National Library of Medicine, 2021, pmc.ncbi.nlm.nih.gov/articles/PMC7814254/.

“Landslide and Disaster Preparedness in Japan.” PreventionWeb, 8 July 2021, www.preventionweb.net/news/landslide-and-disaster-preparedness-japan.