Rainfall Warning Model for Rainfall-Triggered Channelized Debris Flow Based on Physical Model Test—A Case Study of Laomao Mountain Debris Flow in Dalian City

Yuzheng Wang,Lei Nie,Chao Du,Yuanyuan He,Min Zhang,Yan Xu,Lihaolin Jin,Zhengguo Li,Chang Liu,Chonghao Bao,Xiangjian Rui,Yuhang Teng,Tao Zhang,Fansheng Kong

doi:10.3390/w13081083

Abstract

Debris flows are among the most frequent and hazardous disasters worldwide. Debris flow hazard prediction is an important and effective means of engineering disaster mitigation, and rainfall threshold is the core issue in debris flow prediction. This study selected the Laomao Mountain debris flow in Dalian as the research object and explored the relationship among the percentage of coarse sand content of soil, rainfall conditions and the critical rainfall values that induce debris flows on the basis of field investigation data, combined with the results of a flume test, soil suction measurement and geomechanical analysis. The new multi-parameter debris flow initiation warning models were obtained through the mathematical regression analysis method. The critical rainfall values of debris flows in this area were calculated by the previous research on the mechanism of hydraulic debris flow initiation (HIMM). Lastly, the multi-parameter debris flow initiation warning models were compared and analyzed with the critical rainfall values obtained using the HIMM method and the rainfall information available in historical rainfall data, and the reliability of the models was verified. The comparison results showed that the new multi-parameter debris flow initiation warning models can effectively modify the traditional intensity–duration model and have certain reliability and practical values. They can provide an effectual scientific basis for future work on the monitoring and prediction of debris flow disasters.

Highlights

Debris flows are a type of sudden natural disaster in mountainous areas and a complicated natural geomorphological process [1]
The soil structure was in the critical state of instability, and there was no integrity damage
The matrix suction reflected the change in internal stress of the soil structure, which showed an evident decreasing rule after the rainfall started

Summary

Introduction

Debris flows are a type of sudden natural disaster in mountainous areas and a complicated natural geomorphological process [1]. They are among the most frequent and costly hazards worldwide [2]. Nearly 8500 debris flows are distributed across 29 provinces, with an area of approximately 4.3 km × 106 km [6]. This finding shows that early warning of mudslide disasters is highly necessary

Methods

Results

Conclusion