Landslide dam failure and flood hydraulics. Part II: coupled mathematical modelling
Landslide dam failure and flood hydraulics. Part II: coupled mathematical modelling
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DOI：
10.1007/s11069-011-9815-7
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发表时间：
2011-04
期刊：
影响因子：
3.7
通讯作者：
Z. Cao;Z. Yue;G. Pender
中科院分区：
文献类型：
--
作者：
Z. Cao;Z. Yue;G. Pender
一个耦合的二维数学模型研究滑坡溃坝和洪水，补充我们的实验研究中提出的配套文件。该模型建立在浅水水动力学方程基础上。控制方程的数值求解使用总变差减小版本的二阶加权平均通量法沿着与HLLC（Harten，Lax和货车Leer与接触波恢复）近似黎曼解。两个参数有关的推移质输沙和临界边坡稳定性进行了校准使用的水位线从两个水槽试验运行。校准模型，然后应用到其他独立运行的实验具有不同的流入流量，大坝几何形状，大坝组成和初始突破尺寸。它被发现能够令人满意地再现实测水位过程线和初始突破的扩大。确定了入流流量和初始溃口在决定溃坝过程和洪水中的主要作用的实验观测结果，沿着解决了大坝几何形状以及大坝中粘性粘土和砾石含量的影响。有趣的是，下游洪峰流量和洪水的阶段大大减少了初始突破，这清楚地证明了它在调节洪水的作用。
A coupled 2D mathematical modelling study of landslide dam failure and flood is presented, complementing our experimental investigation presented in the companion paper. The model is built upon the shallow water hydrodynamic equations. The governing equations are numerically solved using the total-variation-diminishing version of the second-order weighted-average-flux method along with the HLLC (Harten, Lax and van Leer with Contact wave restored) approximate Riemann solver. Two parameters related to bed-load sediment transport and critical slope stability are calibrated using the measured stage hydrographs from two runs of the flume experiments. The calibrated model is then applied to other independent runs of the experiments featuring different inflow discharges, dam geometry, dam composition and initial breach dimensions. It is found to be able to satisfactorily reproduce the measured stage hydrographs and the widening of initial breach. The experimental observation of the prime role of the inflow discharge and initial breach in dictating the dam failure process and flood is unequivocally resolved, along with the impacts of dam geometry as well the content of cohesive clay and gravel in the dam. Interestingly, the downstream peak discharge and stage of the flood are substantially reduced by initial breach, which clearly exemplifies its role in modulating the flooding.