Development of a Numerical Model for the Formation of Complete and Incomplete Channel Blockages and Their Influences on River Flow
Abstract
Large landslides, triggered by torrential rain or earthquakes, can slide down mountainous slopes and block river channels at the lower end of the slopes. In cases where the landslide volume is relatively small compared to the river discharge, or when the distance between the landslide slope and the river channel is long, incomplete channel blockages may occur due to an insufficient supply of landslide material to fully block the river flow. Since the shape of the channel blockage is the final result obtained through the temporal changes in landslide material movement, river flow, and topography, considering their interactions, it is necessary to investigate the blockage shape by numerical analysis that accounts for these interactions. Therefore, we developed a numerical model to predict the formation of various channel blockages by incorporating the combined conditions of topography, landslide volume, and river discharge. The developed model is a two-dimensional (2-D) model, which can connect several one-dimensional calculation areas for mountainous streams at any selected point in the 2-D area. In addition, the model can consider landslide material movements represented by cylindrical blocks. To verify our model and identify appropriate values for the associated parameters, we investigated the MAE (mean absolute error) for the deposit thickness distribution and the PWO (percentage of the area where the actual and calculated waterlogged areas overlapped) between the actual and calculated results using our model for two previous channel blockages of different sizes. Although our model and the associated parameters still need to be improved by considering the loss of landslide material, they are useful for estimating the magnitude and area of damage caused by large-scale landslides and the associated channel blockage and waterlogging in various river channels with steep side slopes. The calculated results can be utilized in investigating disaster countermeasures for landslides in the area.
References
Akazawa, F., Ikeda, A., Hayami, S., Harada, N., Satofuka, Y., Miyata, S. and Tsutsumi, D. (2014), âNumerical simulation of landslide dam deformation by overtopping flowâ, International Journal of Erosion Control Engineering, 7(3), 85â91. URL: https://doi.org/10.13101/ijece.7.85
Awal, R., Nakagawa, H., Kawaike, K., Baba, Y. and Zhang, H. (2008), âAn integrated approach to predict outflow hydrograph due to landslide dam failure by overtopping and slidingâ, Proceeding of Hydraulic Engineering, 52, 151â156. URL: https://doi.org/10.2208/prohe.52.151
Chen, K. T., Chen, X. Q., Hu, G. S., Kuo, Y. S., Huang, Y. R. and Shieh, C. L. (2019), âDimensionless assessment method of landslide dam formation caused by tributary debris flow eventsâ, Geofluids, 7083058. URL: https://doi.org/10.1155/2019/7083058
Costa, J. E. (1985), Floods from dam failures, Open-File Report 85-560, US Geological Survey. URL: https://doi.org/10.3133/ofr85560
Costa, J. E. and Schuster, R. L. (1988), âThe formation and failure of natural damsâ, Geological Society of America Bulletin, 100(7), 1054â1068. URL: https://doi.org/10.1130/0016-7606(1988)100<1054:TFAFON>2.3.CO;2
Crosta, G. B., Imposimato, S. and Roddeman, D. G. (2003), âNumerical modelling of large landslides stability and runoutâ, Natural Hazards and Earth System Sciences, 3, 523â538. URL: https://doi.org/10.5194/nhess-3-523-2003
Fan, X., Dufresne, A., Subramanian, S. S., Strom, A., Hermanns, R., Stefanelli, C. T., Hewitt, K., Yunus, A. P., Dunning, S., Capra, L., Geertsema, M., Miller, B., Casagli, N., Jansen, J. D. and Xu, Q. (2020), âThe formation and impact of landslide dams â state of the artâ, Earth-Science Reviews, 203, 103116. URL: https://doi.org/10.1016/j.earscirev.2020.103116
Fan, X., van Westen, C. J., Xu, Q., Gorum, T. and Dai, F. C. (2012), âAnalysis of landslide dams induced by the 2008 Wenchuan earthquakeâ, Journal of Asian Earth Sciences, 57, 25â37. URL: https://doi.org/10.1016/j.jseaes.2012.06.002
Hung, J. J. (2000), âChi-chi earthquake induced landslides in Taiwanâ, Earthquake Engineering and Engineering Seismology, 2(2), 25â32.
Inoue, K. and Doshida, S. (2012), âComparison of distribution of disasters occurring in 1889 and 2011 on Kii Peninsulaâ, Journal of Japan Society of Erosion Control Engineering, 65(3), 42â46. In Japanese with English abstract. URL: https://doi.org/10.11475/sabo.65.342
Ishizuka, T., Kaji, A., Morita, K. and Mizuyama, T. (2017), âAnalysis for a landslide dam outburst flood in Ambon Island, Indonesiaâ, International Journal of Erosion Control Engineering, 10(1), 32â38. URL: https://doi.org/10.13101/ijece.10.32
Iverson, R. M. (1997), âThe physics of debris flowsâ, Reviews of Geophysics, 35(3), 245â296. URL: https://doi.org/10.1029/97RG00426
Li, M., Sung, R., Dong, J., Lee, C. and Chen, C. (2011), âThe formation and breaching of a short-lived landslide dam at Hsiaolin Village, Taiwan â Part II: Simulation of debris flow with landslide dam breachâ, Engineering Geology, 123(1-2), 60â71. URL: https://doi.org/10.1016/j.enggeo.2011.05.002
Liao, H., Yang, X., Lu, G., Tao, J. and Zhou, J. (2019), âExperimental study on the river blockage and landslide dam formation induced by rock slidesâ, Engineering Geology, 261, 105269. URL: https://doi.org/10.1016/j.enggeo.2019.105269
Nakagawa, H., Takahashi, T., Sawada, T. and Satofuka, Y. (1996), âDesign hydrograph and evacuation planning for debris flowâ, Annual Report of Disaster Prevention Research Institute, Kyoto University, 39(B-2), 347â371. In Japanese with English abstract.
Peng, M. and Zhang, L. M. (2012), âBreaching parameters of landslide damsâ, Landslides, 9(1), 13â31. URL: https://doi.org/10.1007/s10346-011-0271-y
Sassa, K. (2005), âLandslide disasters triggered by the 2004 Mid-Niigata Prefecture earthquake in Japanâ, Landslides, 2(2), 135â142. URL: https://doi.org/10.1007/s10346-005-0054-4
Satofuka, Y. (2004), âNumerical simulation of the debris flow at the Atsumari River, Minamata City, 2003â, Annual Journal of Hydraulic Engineering, 48, 925â930. In Japanese with English abstract. URL: https://doi.org/10.2208/prohe.48.925
Satofuka, Y. and Takahashi, T. (2003), âNumerical simulation of a debris flow caused by landslideâ, Annual Journal of Hydraulic Engineering, 47, 583â588. In Japanese with English abstract. URL: https://doi.org/10.2208/prohe.47.583
Swanson, F. J., Oyagi, N. and Tominaga, M. (1986), âLandslide dams in Japanâ, in Proceedings of Landslide Dams: Processes, Risk, and Mitigation, ASCE Geotechnical Special Publication No. 3, American Society of Civil Engineers, pp. 131â145.
Takahashi, T. (1991), Debris Flow, Balkema, Rotterdam.
Takahashi, T. (2007), Debris Flow: Mechanics, Prediction and Countermeasures, Taylor Francis Ltd, London.
Takahashi, T. and Kuang, S. (1988), âHydrograph prediction of debris flow due to failure of landslide damâ, Annual Report of Disaster Prevention Research Institute, Kyoto University, 31(B-2), 601â615. In Japanese with English abstract.
Takahashi, T. and Nakagawa, H. (1993), âEstimation of flood/debris flow caused by overtopping of a landslide damâ, in Proceedings of the 25th IAHR World Congress, Vol. III, Tokyo, pp. 117â124.
Takayama, S., Miyata, S., Fujimoto, M. and Satofuka, Y. (2021), âNumerical simulation method for predicting a flood hydrograph due to progressive failure of a landslide damâ, Landslides, 18, 3655â3670. URL: https://doi.org/10.1007/s10346-021-01712-7
Van Tien, P., Sassa, K., Takara, K., Fukuoka, H., Dang, K., Shibasaki, T., Ha, N. D., Setiawan, H. and Loi, D. H. (2018), âFormation process of two massive dams following rainfall-induced deep-seated rapid landslide failures in the Kii Peninsula of Japanâ, Landslides, 15, 1761â1778. URL: https://doi.org/10.1007/s10346-018-0988-y
Wada, T., Nakatani, K., Satofuka, Y., Mizuyama, T., Kosugi, K. and Miwa, H. (2021), âDevelopment of a numerical model for deposition and flood propagation by multiple inflows of debris flows and river floodsâ, International Journal of Erosion Control Engineering, 14(2), 20â30. URL: https://doi.org/10.13101/ijece.14.20
Walder, J. S. and OâConnor, J. E. (1997), âMethods for predicting peak discharge of floods caused by failure of natural and constructed earthen damsâ, Water Resources Research, 33(10), 2337â2348. URL: https://doi.org/10.1029/97WR01616
Zhong, Q. M., Chen, L. C., Mei, S. Y., Shan, Y., Wu, H. and Zhao, K. P. (2024), âNumerical investigation of hydro-morphodynamical characteristics of a cascading failure of landslide damsâ, Journal of Mountain Science, 21(6), 1868â1885. URL: https://doi.org/10.1007/s11629-023-8411-0
Zhong, Q. M., Chen, S. S., Deng, Z. and Mei, S. A. (2019), âPrediction of overtopping induced breach process of cohesive damsâ, Journal of Geotechnical and Geoenvironmental Engineering, 145(5), 04019012. URL: https://doi.org/10.1061/(ASCE)GT.1943-5606.0002035
Zhou, G. G. D., Zhou, M., Shrestha, M. S., Song, D., Choi, C. E., Cui, K. F. E., Peng, M., Shi, Z., Zhu, X. and Chen, H. (2019), âExperimental investigation on the longitudinal evolution of landslide dam breaching and outburst floodsâ, Geomorphology, 334, 29â43. URL: https://doi.org/10.1016/j.geomorph.2019.02.035
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