南水北调中线工程南北跨度大且为明渠自流输水，冬季输水过程中水温受到天气影响，会导致河北段渠道出现冰情，因此，科学量化评估工程沿线地区冬季气温是分析总干渠冰情发生和演变规律的重要基础。本文选择邯郸、正定、涿州为代表地区，利用1979—2021年冬季逐日气温数据，分析了各代表区气温序列统计频率分布与理论概率分布的拟合情况，提出了标准化温度指标（Standardized Temperature Index, STI），并据此建立了新的冬季冷暖量化评估模型。结果表明：（1）STI方法与国标法的冬季冷暖评估结果基本一致，但在各代表区强冷冬和强暖冬划定上，STI评估得出的年份数量均少于国标法；（2）各代表区以1月份气温计算得出的冷暖等级阈值对应的气温值均明显低于按整个冬季3个月计算结果。工程所在纬度越高，冬季冷暖等级阈值对应的气温值越低；（3）根据STI评估结果，邯郸、正定、涿州发生强冷冬概率分别为7.14%、9.52%和4.76%，发生弱冷冬及以上的概率分别为38.10%、40.48%和38.10%，发生平冬的概率分别为21.43%、28.57%和21.43%，发生弱暖冬及以上的概率分别为40.48%、30.95%和40.48%，发生强暖冬的概率分别为4.76%、7.14%和2.38%。研究成果与基于正态分布的国标法相比，考虑了气温序列的偏态性概率分布特征，对相对冷暖的判别更科学，有推广应用价值。

A large north-south area with self-flowing water transportation was spanned by the Middle Route of the South-to-North Water Diversion Project. During the winter water transportation process, the water temperature is affected by weather, which can lead to ice conditions in the Hebei section of the channel. Therefore, scientific and quantitative evaluation of winter temperature in the areas along the project is an important basis for analyzing the occurrence and evolution of ice conditions in the main canal. In this study, Handan, Zhengding, and Zhuozhou were used as representative regions, and the fitting of Statistical frequency distribution and theoretical probability distribution was analyzed using daily winter temperature data from 1979 to 2021. Additionally, a new quantitative evaluation model for winter temperature was proposed based on the Standardized Temperature Index method. The results showed that: (1) The Standardized Temperature Index method's evaluation of cold and warm conditions in winter was generally consistent with the national standard method. However, fewer years for delineating strong cold winters and warm winters in each representative area was evaluated by the Standardized Temperature Index method compared to the national standard method. (2) The temperature values corresponding to cold and warm level thresholds, calculated based on January temperature in each representative area, were significantly lower than those calculated based on the entire three months of winter. The temperature value decreased as the representative area moves farther north. (3) According to the evaluation of Standardized Temperature Index method, the probabilities of strong cold winter occurrence in Handan, Zhengding, and Zhuozhou were 7.14%, 9.52%, and 4.76%, respectively. The probabilities of weak cold winter and above occurrence are 38.10%, 40.48%, and 38.10%, respectively. The probabilities of normal winter were 21.43%, 28.57% and 21.43%, the probabilities of weak warm winter and above occurrence were 40.48%, 30.95% and 40.48, respectively, and the probabilities of strong warm winter were 4.76%, 7.14% and 2.38%, respectively. Compared to the national standard method based on the normal distribution, the characterization of skewed probability distribution of temperature series was considered through these results, making it more scientifically sound in distinguishing relative temperature conditions and more valuable for promotion and application.

TV68

国家重点研发计划项目；水利青年科技英才资助项目