A polygonal-mesh based numerical method is developed to simulate sediment transport in mobile-bed streams with free surfaces. The flow and sediment transport governing equations are depth-averaged and solved in the two-dimensional (2D) horizontal space. The flow and sediment transport are further coupled to the stream bed changes so that erosion and deposition processes are simulated together with the mobile bed changes. Multiple subsurface bed layers are allowed so that bed stratigraphy may be taken into consideration. The proposed numerical discretization is valid for the most flexible polygonal mesh type which includes all existing meshes in use such as the quadrilateral-triangle hybrid mesh. The finite-volume method is adopted such that the mass conservations of both water and sediment are satisfied locally and globally. The sediment transport and stream bed processes are formulated in a general way so that the proposed numerical method may be applied to a wide range of streams and suitable for practical stream applications. The technical details of the numerical method are presented; model verification and validation studies are reported using selected cases having physical model or field measured data. The developed model is intended for general-purpose use available to the public.

中文翻译：

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具有多边形网格的二维深度平均泥沙输运移动床模型

开发了一种基于多边形网格的数值方法来模拟具有自由表面的移动床流中的泥沙输运。流动和泥沙输送控制方程在二维 (2D) 水平空间中进行深度平均和求解。水流和泥沙输送进一步与河床变化耦合，从而模拟侵蚀和沉积过程以及移动床变化。允许多个地下床层，以便可以考虑地层。建议的数值离散化适用于最灵活的多边形网格类型，其中包括所有现有的使用网格，例如四边形-三角形混合网格。采用有限体积法，使得水和沉积物的质量守恒在局部和全局都得到满足。泥沙输运和河床过程以一般方式制定，因此所提出的数值方法可以应用于广泛的河流，并适用于实际的河流应用。介绍了数值方法的技术细节；使用具有物理模型或现场测量数据的选定案例报告模型验证和验证研究。开发的模型旨在供公众使用。