基于高分辨率格点数据长江航道小时尺度雾发生时空规律研究

Study on the Spatiotemporal Patterns of Fog Occurrence in the Yangtze River Navigation Channel Based on High-Resolution Grid Data at Hourly Scale

长江作为中国的重要“黄金水道”,与公路、铁路共同构成了中国庞大的交通物流网络。长江的通航环境对气象条件尤其敏感,特别是对影响能见度的雾。由于传统雾观测数据在定义、持续时间统计窗口和地形复杂区域的站点空间代表性方面存在不足,本研究利用1951~2016年中国地区的天气现象观测数据(A文件)和1979~2018年的格点化高分辨率气象大数据,采用大数据方法,探索长江航道及其沿岸地区的雾气候态发生的时空规律。研究发现,长江上游的荆州至宜昌,奉节至武陵航段的雾小时数相对较少;而在三峡库区,宜昌至奉节航段的雾小时数是整个长江水道中最多的,紧随其后的是武陵至涪陵航段。季节性分析显示,夏半年(4月至9月),宜昌至奉节航段的雾小时数远高于其他航段;而在冬半年(10月至次年3月),这一航段的雾小时数则明显低于其他航段,且安庆至武汉航段的雾小时数超过了下游宝山至安庆航段。雾事件通常出现在气温6℃~17℃、湿度0.005~0.0075 kg/kg、气压1010~1020 hPa、风速0.9~2 m/s的条件下。本研究的结果为长江航道大雾的时空分布特征提供了定量分析,实现了雾的航道公里级发生小时区划,为长江航道运营管理提供了更好的服务。

The Yangtze River, as an important “golden waterway” in China, together with highways and railways, forms a huge transportation and logistics network in China. The navigational environment of the Yangtze River is particularly sensitive to meteorological conditions, especially fog affecting visibility. Due to shortcomings in traditional fog observation data in terms of definition, duration statistics window, and spatial representativeness of station sites in complex terrain regions, this study utilizes weather phenomenon observation data in China from 1951 to 2016 (A file) and gridded high-resolution meteorological big data from 1979 to 2018. By using big data methods, it explores the spatiotemporal patterns of fog occurrences along the Yangtze River and its adjacent areas. The study found that the number of fog hours from Jingzhou to Yichang in the upper reaches of the Yangtze River and from Fengjie to Wuling is relatively low;however, in the Three Gorges Reservoir area, the number of fog hours from Yichang to Fengjie is the highest along the entire Yangtze waterway, followed closely by the Wuling to Fuling section. Seasonal analysis shows that during the summer half-year (April to September), the number of fog hours from Yichang to Fengjie is much higher than in other sections;while during the winter half-year (October to March of the following year), the number of fog hours in this section is significantly lower than in other sections, with the fog hours from Anqing to Wuhan exceeding those in the downstream Baoshan to Anqing section. Fog events typically occur under conditions of temperature 6˚C~17˚C, humidity 0.005~0.0075 kg/kg, pressure 1010~1020 hPa, and wind speed 0.9~2 m/s. The results of this study provide a quantitative analysis of the spatiotemporal distribution characteristics of heavy fog along the Yangtze River, achieve kilometer-level hour zoning for fog in the waterway, and provide better service for the operation and management of the Yangtze River waterway.