## 6 Conclusions  
An experimental study was carried out to investigate river blockages caused by landslides in an experimental setup that consists of a water flume with dynamic water flow. Various slope conditions and landslide materials were tested to explore the influences of slide angle, particle size of deposit, and landslide volume on the river blockage type and degree. Asymmetrical cross-sections of landslide dams were observed. The flow of the water makes the upstream dam slope steeper than the downstream dam slope, and the volume of final deposition decreases after some of the landslide material is washed away.  
The degree of river blockage varies from 70% to 100% and increases with increasing chute angle, particle size, and landslide volume. Thus, river blockage is divided into two categories: partial blockage and complete blockage. Furthermore, six subtypes of river blockage were summarized according to the differences between the water depth and the height of the landslide dam. The initial volume of landslides is the key factor controlling the landslide dam height and blockage degree. Landslides with larger particle sizes are more likely to form landslide dams with small height differences and completely block rivers. The increase in slide angle will significantly increase the landslide velocity entering the river, which further affects the formation process and type of landslide dam.  
Based on 60 real landslide cases, the influence degrees of these factors are sorted according to key geometric attributes, including landslide size, steepness of the topography, width of the valley, and length of the landslide. An improved probability model was developed to assess the possibility of complete blockage under the influence of these factors. The coefficients of the model were obtained by logistic regression analysis, and the overall prediction accuracies of the experimental results and real landslide cases were approximately 91.1% and 83.3%, respectively, which are accurate enough to predict the blockage state of landslide dams. The proposed model is applicable to more complicated landslide cases by considering more factors that could affect river blockage.  
This study has a shortcoming in that the experiment and the proposed model do not include the influence of water flow velocity, which could affect the formation of a landslide dam if its accumulation process takes a relatively long time. The influence of water flow velocity needs further investigation by designing another special flume chute, which could keep both flow velocity and water depth as specific values.  
Conceptualization, L.Z.; methodology, Y.L.; software, Y.-F.H.; validation, M.-L.X. and H.-Q.X.; formal analysis, Y.-F.H.; investigation, Y.-F.H.; writing--original draft preparation, L.Z. and Y.-F.H.; writing--review and editing, M.-L.X. and Y.L.; visualization, H.-Z.L.; supervision, J.-L.P.; funding acquisition, M.-L.X. and Y.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Chinese Academy of Sciences (CAS) program of the \"Western Youth Scholar\", grant number E2R2050050, and the National Key R&D Program of China, grant number 2017 YFC1501100.  
Not applicable.  
**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to ethical restrictions.  
**Acknowledgments:** The authors sincerely acknowledge [PERSON] and [PERSON] for their help in conducting the laboratory experiments and analyzing the data.  
**Conflicts of Interest:** The authors declare no conflict of interest.