The 3rd Badong International Geohazards Symposium (BIGS2021)

36 / 2021-11-09 10:57:02

Probabilistic Prediction of Debris-Flow Runout Distances on the Depositional Area: A Copula Approach

Debris flow; depositional area; runout distance; copula

Runout distances on depositional areas are the key parameter to delineate potential hazard areas of debris flows for mitigation work design and risk management. However, due to the complex geological processes of debris flows, it still remains a great challenge to properly determine the runout zones. This paper proposed a copula-based framework to probabilistically predict the runout distances. A three-dimensional copula probabilistic model is constructed to model the multivariate distribution of debris flow’s maximum runout distance (L), debris-flow volume (V_D), and catchment internal relief (H). Then the developed model is used to determine the runout distances of debris flows for a specific hazard level. The proposed approaches were illustrated and validated using the debris-flow investigation dataset in Wenchuan earthquake zone. Results show that the probabilistic estimates of runout distances agree well with their respective observed values, providing a rational basis for predicting the hazard zonation of debris flow.

Runout distances on depositional areas are the key parameter to delineate potential hazard areas of debris flows for mitigation work design and risk management. However, due to the complex geological processes of debris flows, it still remains a great challenge to properly determine the runout zones. This paper proposed a copula-based framework to probabilistically predict the runout distances. A three-dimensional copula probabilistic model is constructed to model the multivariate distribution of debris flow’s maximum runout distance (L), debris-flow volume (V_D), and catchment internal relief (H). Then the developed model is used to determine the runout distances of debris flows for a specific hazard level. The proposed approaches were illustrated and validated using the debris-flow investigation dataset in Wenchuan earthquake zone. Results show that the probabilistic estimates of runout distances agree well with their respective observed values, providing a rational basis for predicting the hazard zonation of debris flow.