GIS-Driven Landslide Resilience: The Taroko Digital Twin

On the morning of October 17, 2025, a massive collapse of steep marble cliffs along the Yanzikou (Swallow Grotto) Trail in Taroko National Park, Taiwan, blocked the Liwu River, instantly creating a landslide-dammed lake. Within hours, a multiagency task force—including Taroko National Park Headquarters, the Hualien District Office of the Forestry and Nature Conservation Agency, the Directorate General of Highways, and the Xiulin Township Office—activated emergency protocols for on-site inspections, road closures, and precautionary evacuations.

As agencies worked to assess evolving conditions, ongoing rockfalls made traditional ground surveys impossible, forcing decision-makers to rely on fragmented data from seismic monitoring, field observations, and emergency response teams. To improve situational awareness and public communication, the Center for Humanities Innovation and Social Practice (CHISP) used geographic information system (GIS) technology, including ArcGIS Online, to integrate information from multiple sources and develop a Taroko digital twin that visualized conditions as they evolved.

CHISP is an institute-level research center affiliated with the College of Humanities and Social Sciences at National Dong Hwa University. The Center is directed by associate professor Chun Lin Kuo from the Department of Taiwan and Regional Studies. Grounded in the humanities, the center combines innovative research with practical community engagement, supporting local communities and civic groups through spatial data integration, analysis, and participatory digital transformation initiatives.

Following the crisis, CHISP used ArcGIS StoryMaps to transform operational records into a lasting digital resource for geological hazard education and resilience planning. This timeline highlights the critical stages of the response, from initial collapse through stabilization, and demonstrates how GIS-supported collaboration helped agencies manage a rapidly evolving emergency.

The crisis began at 4:58 a.m. on October 17, when microseismic sensors detected an 18-second massive collapse that blocked the Liwu River. The primary challenge was the extreme risk of continuous rockfalls, which rendered traditional ground surveys completely impossible. During the emergency, decision-makers had to rely on fragmented data—including seismic alerts and manual observations—to predict potential breach scenarios threatening downstream settlements and power infrastructure. This volatility demanded a unified spatial platform to synchronize multiagency data and provide transparent information to both officials and a concerned public.

According to microseismic detection and field investigations conducted by the National Yang Ming Chiao Tung University (NYCU) Disaster Prevention and Water Environment Research Center and its partners, the primary collapse instantly formed the natural dam. To manage the risks, Taroko National Park declared a full closure and evacuated all visitors. Disaster response teams, alongside staff from the Forestry and Nature Conservation Agency, entered the site to assess the dam and install real-time monitoring equipment.

On Oct 18 at 9:47 a.m., ongoing rockfalls continued to occur along the surrounding cliffs. Lake water spilling through the tunnel indicated active overtopping. River water can be seen flowing downstream through the Ludan Bridge area. On the afternoon of October 20, the construction team arrived at the dam crest and began excavation to lower the barrier and reduce risk.

By October 20, the NYCU Smart Monitoring Dashboard went online, integrating water-level and rainfall data for real-time visualization. This GIS-driven approach enabled contractors to safely arrive at the dam crest to begin strategic crest-lowering and diversion works. As of October 20, the dam reached approximately 40 meters in height with a lake area of 10.5 hectares; continuous monitoring through the dashboard ensured that water levels were gradually reduced via controlled outflow.

Following a joint field inspection on October 19 by the Xiulin Township Office, the Forestry and Nature Conservation Agency, and NYCU, the impact zone was delineated based on actual elevation differences. The analysis identified that the Minle Settlement of Fushi Village, situated on a low river terrace, and the Chongdeying Campground, at an elevation of under 10 meters, remained highly susceptible to inundation. National Dong Hwa University utilized a digital twin to help illustrate the surrounding terrain and highlight high-vulnerability zones.

By October 29, monitoring indicated accelerated erosion at the spillway. At 11:30 a.m., a controlled breach occurred, resulting in significant overtopping flow. While some localized sedimentation was reported, there were no serious injuries or major infrastructure failures. The crisis was successfully resolved through data-driven precision.

Following the stabilization of the site, CHISP synthesized these operational records into a digital story using ArcGIS StoryMaps. The use of GIS for post-event reconstruction has provided lasting value. The digital story meticulously preserves the response logic, from the initial collapse to the natural overflow beneath Chief’s Rock on October 18, and finally to the road reopening on October 31.

By archiving the Forestry and Nature Conservation Agency’s mitigation strategies alongside 3D GIS models, this project serves as a premier educational resource. It demonstrates that effective disaster management is not just about the response itself, but also about the ability to translate complex GIS data into a transparent, shareable record that builds institutional knowledge and public trust.