The 3rd Badong International Geohazards Symposium (BIGS2021)

27 / 2021-10-28 18:07:55

Hazard Prediction Method of Landslide Damming and its Application Analysis of the Baige Landslide Damming Case

Disaster Chain,Landslide Dam,River Blocking,Hazard Prediction Method

Landslide damming occurs frequently, affects a wide range of areas, and is difficult to be predicted, threatening the safety of engineering and human life and property. However, studies on early identification are still at an early stage. This paper proposed a hazard prediction method of landslide damming, which contains prediction models of river blockage, landslide dam geometry, landslide dam stability, and dam breach time. On this basis, the landslide damming hazard can be predicted by ten parameters including the repose angle of landslide mass, the landslide volume, the landslide discharge, the river discharge, the reservoir capacity of the barrier lake, the bottom width of the valley, two slope angles on both sides of the valley, the valley bed inclination, and the sliding surface dip-angle. The proposed method is examined by a typical case, which is the Baige landslide damming that occurred in 2018, China, and the application process is also presented integrally. The results show that the river blockage model predicted the Baige landslide may form a huge landslide dam, which is fully in line with the actual situation. The landslide dam geometry model gives the predicted value of the height, the width, the length, the downstream and upstream angle of the Baige landslide dam, and the maximum relative error between the predicted value and the true value is less than 20%. The prediction results of the landslide dam stability model show that when the reservoir capacity of the barrier lake is 280 million m³, the dam may breach. The dam breach time model predicts the dam may breach in 38 h after the landslide dam formation, which is 11% less than the actual breach time of the Baige landslide dam. The current study is helpful to provide theoretical reference and technical support for the early identification, prediction, and early warning of the disaster chain of landslide-induced river blocking.