Hualien uses TVWS to accelerate images, improving landslide warnings.

The upper reaches of the Mataian Creek in Hualien County feature a geological environment characterized by steep slopes and heavily fractured rock formations. Affected by heavy rainfall and typhoons year-round, the area is prone to large-scale debris flows. According to recent measurements, approximately 236 million cubic meters of sediment remain deposited within this river section. If concentrated rainfall or earthquakes trigger debris flows in a short period, a barrier lake is highly likely to form in the valley, posing a further threat to the lives and property of downstream communities. In past years, the Hualien area has experienced multiple floods caused by the overflow or breaching of barrier lakes, highlighting that the real-time monitoring of upstream sediment changes and water levels is the key to disaster prevention.

To enhance disaster early-warning capabilities, the Forestry and Nature Conservation Agency has proactively introduced a new-generation Television White Space (TVWS) communication system. Responsible for mountain resource protection and disaster prevention and relief, the agency has long installed rain gauges and debris flow sirens in mountainous areas. However, constrained by topographical obstruction and the congestion of traditional wireless frequency bands, the real-time transmission of image data has consistently been a technological bottleneck. TVWS utilizes unused television spectrum channels, boasting strong penetration, wide coverage, and low interference, making it particularly suitable for establishing long-distance, low-power communication links in mountainous regions.

This project deployed two communication relay stations in the upper reaches of the Mataian Creek, located respectively on the high points of both sides of the valley to ensure that signals are not blocked by mountain walls. The relay stations are equipped with high-resolution cameras and low-power television spectrum transmitters, transmitting real-time images back to the Forestry and Nature Conservation Agency's monitoring center via TVWS. The image data includes not only river water levels and flow velocities but also clearly captures sediment accumulation and potential landslide signs, providing disaster prevention units with visual decision-making references.

The launch of this system allows field footage to be obtained within minutes—a significant improvement over previously relying solely on rain-gauge data updated at intervals of several hours—thereby shortening the time window for disaster warnings. When the monitoring center detects a rapid rise in river water levels or abnormal sediment accumulation, it can instantly trigger alarms to notify local governments and disaster relief units, while simultaneously issuing evacuation advisories to downstream residents. In the long run, the continuously accumulated image and hydrological data will also become an important foundation for academic research and river management.

Beyond enhancing local disaster prevention efficiency, the successful application of TVWS in remote mountainous areas also provides a viable model for other high-risk rivers across the country. In the future, if combined with artificial intelligence image analysis, the system may automatically detect early signs of barrier lake formation, further reducing blind spots in manual monitoring. This move not only strengthens Hualien's disaster resilience but also demonstrates the practical value of technology in the field of public security, laying the foundation for the upgrading of Taiwan's overall disaster prevention system.