The Hualien region in Taiwan has recently been the site of significant geological activity following the 7.4 magnitude earthquake on April 3, 2024. This seismic event has caused numerous landslides, one of which has led to the formation of a valley-blocking landslide in Hualien County. The incident was documented through various imaging techniques by the Forestry and Nature Conservation Agency in Taiwan, which captured crucial data on the landslide’s dimensions and its consequent impact on the surrounding landscape and river flow.
The landslide has created a substantial barrier across a local river, resulting in a barrier lake approximately 700 meters in length and containing around 430,000 cubic meters of water. The dam created by the landslide rises about 30 meters high, posing potential risks to the surrounding areas. Although the area is not densely populated, the presence of two small hydroelectric schemes downstream could be affected by the changed river dynamics. Approximately 15 kilometers downstream, the village of Tongmen sits safely elevated 20 meters above the river level, minimizing its risk of direct impact.
Further complicating the situation is a detailed image from Planet Labs, captured on April 17, 2024. This image, integrated with data from Google Earth’s Digital Elevation Models (DEM), provides a clearer picture of the dam’s condition. Observations indicate that water has begun to overtop the landslide dam, leading to a steady flow downstream. This situation necessitates ongoing monitoring, particularly with the approaching typhoon season, which could exacerbate conditions and increase the risk of further geological disturbances.
As the situation develops, it remains critical for local authorities and conservation agencies to maintain vigilant monitoring of the landslide’s impact. The need for detailed analysis and preparedness plans is imperative to mitigate potential damages to infrastructure and ensure the safety of the affected communities.
