河流水冰沙耦合模型研究Ⅰ：原理和方法

河流水沙研究一般忽略冬季河冰对泥沙输运、河床侵蚀和岸滩崩塌的影响,但北方河流如黄河等冬季冰期的防凌减灾和河道的演变均不能忽略河冰过程,亟需研究河冰全过程影响下的水冰沙耦合作用机理。本文首先总结了河冰水力学的理论发展,针对北方河流建立了二维水冰沙耦合数学模型,包括二维水沙数值模块、河冰动力学模块和岸滩侵蚀模块,并介绍了该耦合模型的求解步骤和方法。研究表明:通过三个模块间的信息传递和数据反馈,该数学模型具备模拟冰塞冰坝等极端工况下的水流变化、河冰堆积和释放、泥沙运动、河床冲淤和岸滩侵蚀等过程的能力。该模型将水沙理论和河冰理论结合起来,可用于北方河流全季节与河冰生消全过程的水冰沙耦合过程模拟,为北方河流管理提供了有力工具。

A two-dimensional flow-ice-sediment coupled model for rivers I: Theory and methods

Traditional flow and sediment research generally neglect the effect of ice-affected sediment transport and riverbank erosion. However, ice effects are unavoidable in northern rivers considering ice jam flooding, ice gouging, and abrasion on riverbanks. It is important to understand the complex flow-ice-sediment coupling mechanics in ice jam events. This study firstly reviews the theoretical progress in river ice research in the last several decades. It then presents a two-dimensional flow-ice-sediment coupled model with bank stability for Northern rivers. The model is constructed of flow and sediment transport module,river ice dynamic module, and bank erosion and mass failure module. Through the information exchange and feedbacks between these three modules, the coupled model can simulate water level and discharge fluctuations, dynamic ice floe transport, sediment transport, riverbed change, and bank erosion and failure. The model combines theories of sediment transport and river ice, satisfying requirements of flow simulations for both ice-free and ice-affected rivers for all seasons. It provides a new tool for northern river management in preventing ice jam flooding. Such a study can contribute to the interdisciplinary research between flow hydraulics,river ice mechanics,and river dynamics.