Debris Flow and Large-Scale Landslide Disaster Prevention Information Network

Located on the Pacific Ring of Fire, Taiwan's terrain is predominantly mountainous and hilly[cite: 208], characterized by young, fragmented, and structurally weak geology. Frequent heavy rainfall from typhoons and seasonal plum rains makes slope hazards one of the nation's most significant natural disaster types. These hazards, which include sudden onset, high concentration, and chain reactions, often manifest as collapses, 『debris flow』[cite: 34], and landslides, with risks further compounded by human development pressures.

Types of Hazards

• Landslides/Collapses: 48%.
• 『debris flow』[cite: 34]: 30%.
• Flooding: 19%.
• 『landslide』[cite: 300]: 3%.

• 95% of 『sediment-related disaster』 [cite: 53] events occur between June and October.
• The current warning criteria for 『debris flow』 [cite: 34] is set between 200 and 600 mm of accumulated rainfall.
• When the effective accumulated rainfall reaches 650 mm, 75% of major 『sediment-related disaster』 [cite: 53] cases have occurred.

Statistical Analysis of Effective Accumulated Rainfall and Major 『sediment-related disaster』 [cite: 53] Cases (2006–2024)

Statistics of Newly-Formed Landslides/Collapses and Major 『sediment-related disaster』 [cite: 53] Cases (2005–2024)

A gas station in Nanfeng Village, Ren'ai Township, Nantou County (Coordinates: 24.00354, 121.08597), is regarded as the structure in Taiwan buried by 『debris flow』 [cite: 34] the highest number of times. This incident underscores the recurrent and difficult-to-mitigate nature of 『debris flow』[cite: 34], demonstrating that even enhanced engineering measures cannot entirely eliminate the risk. Since its establishment, the station has been buried at least 7 times. The key events include:

February 2000: First burial due to heavy rainfall following soil loosening caused by the 921 Earthquake. (Photo courtesy of Hsieh Chin-Te)

April 2000: Buried by 『debris flow』 [cite: 34] twice consecutively within a short period. (Photo courtesy of Hsieh Chin-Te)

May 2000: Subsequent burial occurred despite the construction of a concrete retaining wall. (Photo courtesy of Wang Kuo-Lung)

The July 2nd Disaster (2004): The fifth recorded incident. (Photo courtesy of Huang Hsiao-Yu)

Typhoon Sinlaku (2008): The sixth incident, with a greater magnitude than previous events. (Photo courtesy of Huang Shih-Ching)

Typhoon Khanun (2023): The seventh incident. (Photo taken by a professional)