A combination weighting method for debris flow risk assessment based on t-distribution and linear programming...

Area of Science:

• Geosciences
• Natural Hazard Assessment
• Risk Management

Background:

• Debris flow risk assessment is crucial for prevention and control projects.
• Existing methods often overemphasize objective or subjective indicators, neglecting indicator interactions.
• Traditional methods like EWM and VCM overlook the impact of debris flow frequency on risk.

Purpose of the Study:

• To propose a new weight calculation method for debris flow risk assessment.
• To integrate t-distribution and linear programming optimization algorithm (LPOA) for robust weighting.
• To enhance risk assessment accuracy by avoiding overemphasis on single indicators and incorporating frequency effects.

Main Methods:

• Initial weights derived using Analytic Hierarchy Process (AHP), Entropy Weight Method (EWM), and Variation Coefficient Method (VCM).
• Weight intervals determined using t-distribution at various confidence levels.
• Final weights calculated via LPOA within a 90% confidence interval for debris flow risk scoring.

Main Results:

• The proposed method avoids overemphasizing individual indicators compared to EWM and VCM.
• The fusion weighting method effectively incorporates debris flow frequency, a factor missed by EWM and VCM.
• In Beichuan County, 72 debris flows were assessed, with most categorized as moderate and light risks (8 high, 24 medium, 40 light).

Conclusions:

• The developed fusion weighting method provides a more rational and comprehensive approach to debris flow risk assessment.
• The method's ability to avoid single-indicator bias and include frequency effects enhances its applicability.
• Findings offer valuable insights for combination weighting methods and debris flow risk management strategies.