Nature’s ruthlessness is shown in dramatic landscape changes after the Fata’an River dam-break, according to the Agriculture Ministry’s newly released LiDAR scanning technology.

The Agriculture Ministry released its airborne LiDAR scanning technology results last week, comparing the topographic data for the Fata’an River dam-break pre- and post-disaster. The results revealed significant terrain changes from the upstream mountainous area to the downstream riverbed.

LiDAR (Light Detection and Ranging) is a remote sensing method that uses pulsed lasers to measure distances, creating high-resolution, 3D models of the environment.

The once vast, emerald-green lake has shrunk to a small pond after the massive overflow. The blue-purple area upstream of Fata’an represents the deepest subsidence caused by the landslide, while the orange-red area shows the accumulation of debris. The yellow area downstream of Fata’an shows the debris carried downstream by the floodwaters.

Aerial and Remote Survey Director Huang Chyun-Shiou (黃群修) says that in some areas around the dam-break lake, the landslide depth reached 403 meters. He details that a large amount of sediment remains in the riverbed, which is also constantly moving. Therefore, continuous monitoring is necessary to develop appropriate management and mitigation strategies.

The data was immediately sent to the National Science and Technology Center for Disaster Reduction and other relevant agencies. More detailed analyses will help with recovery and restoration efforts and, most importantly, prevent future disasters by taking proactive measures and respecting the power of nature.