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基于复合气象特征和代价敏感学习的道路结冰预警模型研究

Study on Road Icing Alert Model Based on Composite Meteorological Features and Cost-Sensitive Learning

  • 摘要: 道路结冰是受复杂气象条件及历史热惯性共同调控的物理过程,特征指标简单、样本类别不均衡是导致道路结冰漏报的重要诱因。为提升道路结冰模型的预测性能,本研究利用2020-2025年天津气象观测数据,借鉴积温概念提出了冰冻累积指数、有效冰冻时长等表征历史热惯性的积温特征指标,构建了涵盖实时气象特征、过程累积特征和物理衍生特征的道路结冰复合气象特征体系。基于降水过程开展随机交叉验证,系统评估了逻辑回归、支持向量机和随机森林三种机器学习算法在代价敏感学习、复合特征引入两类优化策略下的建模效果,阐明不同算法最优训练策略的内在作用机制,并基于最优模型开展过程实例验证。结果表明:道路结冰对降水存在0-12h滞后效应,过程累积特征和物理衍生特征可有效区分结冰和非结冰过程。温度露点差、地气温差、有效冰冻时长、12h累计降水量、冰冻累积指数、风寒温度等复合特征重要性高于传统实时特征,融入复合特征可显著提高逻辑回归与随机森林模型性能。优化策略的适配性由算法底层数学逻辑决定:逻辑回归、随机森林算法综合代价敏感学习和复合特征策略时模型性能最优;支持向量机易受损失加权和高维特征干扰,出现模型性能退化。三类模型均具备较好的结冰事件识别能力,在各自最优训练策略下,综合性能由高到低依次为随机森林、支持向量机、逻辑回归。最优随机森林模型精确率、召回率、F1分数和海德基技巧评分均≥0.93,能够准确判断道路结冰过程,为冬季道路交通安全管理提供科学支撑。

     

    Abstract: Road icing is a physical process regulated by complex meteorological conditions and historical thermal inertia. The simplistic constructions of feature indicators and the class imbalanced samples are critical factors leading to missed detections in road icing forecasting. To enhance the forecasting performance of road icing prediction models, this study utilized meteorological observation data from Tianjin for the period 2020-2025. Drawing upon the concept of accumulated temperature, we proposed accumulated temperature feature indicators—such as the cumulative freezing index and effective freezing duration—to characterize historical thermal inertia. Consequently, a composite meteorological feature system for road icing was constructed, encompassing real-time meteorological features, process accumulation features, and physically derived features. By implementing random cross-validation based on precipitation processes, this study systematically evaluated the modeling performance of three machine learning algorithms: Logistic Regression (LR), Support Vector Machine (SVM), and Random Forest (RF), under two optimization strategies: cost-sensitive learning and composite feature integration. The underlying mechanisms of the optimal strategies for different algorithms were elucidated, and case verification was performed using the optimal model. The results indicate that road icing exhibits a lag effect of 0–12 hours following precipitation, and that process accumulation features and physically derived features can effectively distinguish between icing and non-icing processes. Composite features such as temperature–dew point spread, ground–air temperature difference, effective freezing duration, 12-hour accumulated precipitation, freezing accumulation index, and wind chill temperature demonstrate higher importance than traditional real-time features. Incorporating composite features based on prior knowledge can substantially improve the performance of LR and RF models. Furthermore, the adaptability of the optimization strategies is determined by the underlying mathematical logic of each algorithm. The LR and RF algorithm achieve optimal performance when integrating cost-sensitive learning with the composite feature strategy. In contrast, the SVM algorithm is susceptible to interference from loss weighting and high-dimensional features, resulting in performance degradation. All three models demonstrate good icing identification capability. Under their respective optimal training strategies, the models rank in descending order of overall performance as follows: RF, SVM, and LR. The optimal RF model achieves scores of ≥0.93 in precision, recall, F1-score, and Heidke Skill Score (HSS), enabling accurate prediction of road icing processes and providing scientific support for winter road traffic safety management.

     

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