The 23 September 2025 landslide dam breach on the Matai’an River in Taiwan
A new paper (He et al. 2026) in the journal Landslides describes the breach of a massive landslide dam in Taiwan, which killed 24 people. On 23 September 2025, a large landslide dam (located at [23.715, 121.299]) on the Matai’an River in Hualien County in Taiwan catastrophically breached, releasing a flood that left 24 people […]
On 23 September 2025, a massive landslide dam located on the Matai’an River in Hualien County, Taiwan, catastrophically breached, resulting in the deaths of 24 people and injuring 156 others. This disaster, described in a recently published paper by He et al. (2026) in the journal Landslides, is the largest ever recorded in Taiwan and triggered by Tropical Storm Wipha on 19 July 2025.
The landslide, covering an area of 285.90 million cubic meters, formed a dam in the valley below that was 200 meters high. When the lake reached a volume of 67 million cubic meters in the following months, the breach occurred, releasing a flood with two peak flow events: one at 15:38 on 23 September 2025, and a larger one at 16:24, both of which had significant impacts on the surrounding area.
The Google Earth images show the aftermath of the flood, demonstrating the extensive damage to the flood plain below the landslide. Despite the authorities' attempts to evacuate the affected area, relocating only 8.524 people, the loss of life highlights the challenges faced by emergency management systems even in the face of well-understood hazards. The article emphasizes the importance of vulnerability and resilience in disaster response rather than solely relying on early warning systems.
Written by urgent.news from Eos's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
