Common Debris Flow Warning Methods
- Detection Method: Wire ropes, geophones, and other means to detect debris flow
- Advantages: High accuracy
- Disadvantages: Insufficient warning time, difficult equipment maintenance, high construction costs
- Detection Method: Uses rainfall as the debris flow warning threshold
- Advantages: Longer warning time, easier equipment maintenance and data transmission
- Disadvantages: Lower accuracy
Debris Flow Occurrence Conditions and Warning Framework
International Practices for Debris Flow Warning
Japan's RBFN System
Japan launched a nationwide warning system for debris flow and slope disasters in 2005. The system primarily utilizes runoff indices, such as 60-minute cumulative rainfall and a soil moisture index, to set the criteria for debris flow and slope disaster occurrences. Due to the lack of precise records for disaster occurrences in many areas, the system employs the Radial Basis Function Network (RBFN) method to establish a warning model based on the correlation between historical rainfall data and disaster occurrences. Since March 2007, relevant warning information has been disseminated via media such as television, radio, and the internet during heavy rainfall conditions to enhance public disaster awareness and response capabilities.
USGS Warning System
The U.S. Geological Survey (USGS), in partnership with the National Oceanic and Atmospheric Administration (NOAA), established a demonstration flash flood and debris flow warning system in Southern California. This system predicts the likelihood of a debris flow by comparing radar-estimated rainfall data with established rainfall intensity-duration thresholds. When the system determines there is a risk of a debris flow, a warning is issued through the National Weather Service's (NWS) Advanced Weather Interactive Processing System (AWIPS), and relevant emergency response units are notified for appropriate action.
