河冰是寒带特别是高纬度地区冬季江河中普遍存在的自然现象。江河中冰凌直接影响冬季水电站发电、内河航运、水资源调度等水利工程相关事业，尤其若江河中出现冰塞或冰坝等严重冰害，还将导致凌洪泛滥成灾，严重威胁人民生命财产安全。因此，开展河冰研究，防治冰凌危害具有重要的理论及实际意义。本文应用水动力学、河流动力学、气象水文、热力学、河冰水力学、固体力学及地理学等学科理论和方法，建立了可用于对封冻期河冰演变进行连续性描述的综合河冰数学模型，并对实际工程的冰情演变进行了数值模拟。主要研究成果有以下四个方面内容：（1）基于非平衡冰塞理论，提出了厚度沿程变化冰塞体冰-水耦合的数学模型及相应的计算模型，用于准确获取冰塞体完整的纵剖面形状；在此基础上，进一步考虑热力因素影响，针对上游有持续来冰情况，建立了厚度沿程变化冰塞体动态推进模型，用于获取冰塞向上游推进过程中每时刻的完整纵剖面形状。应用实测资料对模型进行了验证分析，结果表明和实测资料吻合较好。（2）应用上述厚度沿程变化冰塞体模型对封冻河道能量损失进行了详尽理论分析，结果表明冰塞体内部渗流所引起的水流能量损失占据水流总能量损失的绝大部分，并随冰厚增加而逐渐增大；运用多孔介质理论，提出了考虑渗流水流阻力的冰塞阻力系数与冰塞厚度的理论关系表达式及便于工程实际应用的冰塞糙率计算公式。通过具体案例研究分析发现，冰塞的阻力系数随冰厚增加而增大，且二者之间成特定的线性变化关系。（3）基于本文提出的上述厚度沿程变化冰塞体动态推进模型，建立了综合河冰数学模型，用于数值模拟冬季河渠道内冰情生消演变过程，主要包括流量水位、水温、冰浓度、冰盖厚度等的时空分布，冰盖底部冰花堆积、冰盖体热力生长厚度等冰情。利用白山河段长系列水文、气象、冰情等现场实测资料对模型进行了验证分析。研究结果表明，模型计算精度较高。（4）将上述综合河冰数值模型应用于伊丹河冰期输水工程及新疆某首部拦河引水枢纽工程两个重大实际工程的冰情研究。根据特定的地形、气象条件，分别对其封冻期河流冰情进行数值模拟，预报冬季冰情生消演变过程，同时对其水力响应特性等进行了详细研究分析。研究结果为输水工程的调度、防凌减灾和运行控制提供了科学依据及工程指导。

River ice is a common natural phenomenon in cold regions and especially in high latitudes in winter. Major hydraulic engineering concerns related to river ice include hydropower operation, inland navigation, and water transfer, etc. Especially when ice jam occurs in river, it may bring ice jam flooding, which has a severe impact on aquatic life and the local economy by destroying habitat or damaging infrastructure and property. It is of great theoretical and practical significance to conduct research on river ice for preventing ice damage. In this paper, a comprehensive river ice mathematical model, which can describe the whole river ice process in winter, is established based on the theories of hydrodynamics, river mechanics, hydrometeorology, thermodynamics, river ice hydraulics, mechanics of solids and geography, etc. Ice conditions of practical projects are numerically simulated by using the river ice model. Main research results consist of four parts:(1) Based on the non-equilibrium ice jam theory, an ice-water coupling mathematical and computational model, which describe the variation of ice jam thickness along the river, is proposed by combining the ice thickness differential equation and the energy equation of the gradient flow. On the basis of the model, considering thermaldynamic, the ice jam dynamic progression model is established under the condition of continuous ice supply from the upstream, and the whole longitudinal profile of the ice jam can be calculated by the model at every moment when ice jam progress to the upstream. The progression model is validated by using the observations, and calculated results are in good agreement with the measured data.(2) By analyzing the energy loss of the freeze-up river reach, it could be found that the energy loss due to the seepage flow through the jam is a dominating part of the total energy loss. The energy loss due to the seepage flow increases with the increasement of ice thickness. Using the theory of porous media, the theoretical expression of the relationship between ice jam friction factor and ice jam thickness is propesed. The case study shows that ice jam friction factor increases with the increasement of ice thickness, and the friction factor vary linearly with ice thickness. In addition, a formula for calculating the Manning roughness coefficient of ice jam is also proposed.(3) Based on the ice jam dynamic progression model proposed by this paper, a comprehensive river ice model is established based on the proposed model of ice cover dynamic progression. The model can be used to simulate the process of river ice conditions in river and channel, which mainly include water level, water temperature, ice concentration, ice cover thickness; ice cover evolution process, the thickness of undercover ice accumulation, and thermal growth of the ice cover in river and channel. The presented model was validated fully against long series of comprehensive field observations including meteorological, hydrological, and ice regime data in Baishan reach. The results show that the model has high accuracy.(4) Using the above comprehensive numerical model of river ice, the river ice conditions of the Yidan River water transfer project in winter and a head water-diversion project in Xinjiang during ice period are numerically simulated, respectively, in terms of the unique geomorphological and meteorological conditions. The process of river ice in water transfer reach is predicted, and the hydraulic response characteristics in the reach during ice period are also analyzed in detail. The presented results provide a scientific basis to instruct the water transfer, ice damage mitigation, operational control of the water transfer project.