中文摘要：

数学模型中参数的不确定性直接影响到模拟结果的不确定性。以南水北调中线工程冬季输水为例，根据实测和设计资料，采用自主开发的大型长距离调水工程冬季输水冰情数值模拟平台，重点分析了冰情数学模型中单一参数（冰期冰盖糙率、大气与冰盖的热交换系数）的不确定性对冰期冰盖形成、发展、消融和水位、流量等要素的影响，并计算给出了一般规律。研究表明，初始冰盖糙率的不确定性对典型年冰期水力学要素的变化过程影响较大，主要反映在沿程各计算断面的水位、流量波动以及结冰期冰盖前缘动态发展模式上，而对冰情范围及与冰相关的变量变化过程无影响。大气与冰盖的热交换系数的不确定性直接影响到最大冰盖厚度的模拟结果，而对冰盖的发展规律影响不大。建议及早准备开展中线工程冰期输水原型观测工作，对上述不确定参数进行率定。

英文摘要：

Uncertainty of model parameters greatly affects the simulation results, and subsequently affects the management and decision making. Based on the numerical modeling system of water conveyance in ice period for large-scale and long distance water channel, the study focused on parameter-induced uncertainty in modeling ice processes which including ice cover forming attd development for the middle route of the South-North Water Diversion Project. The uncertain parameters in this paper involve initial ice roughness and coefficient of heat exchange between air and ice. The results indicate that the uncertainty of initial ice roughness in the mathematical model mainly affects the water stage and discharge variation along the chan- nel and also the progression model of the leading edge, but has little effect on the length of ice covered reaches and variation of ice related variables. The uncertainty of coefficient of heat exchange between air and ice directly affects the maximum thickness of ice cover and has little effect on the rule of ice cover formation. Thus, the further field observations for this project should be performed to calibrate these uncer- tain parameters.