气象因子与地理因子对长江三峡库区雾的影响

为研究长江三峡库区气象因子与地理因子对雾情(能见度)的影响程度,定量描述以厘定影响雾发生的主要气象因子和地理因子,为能见度监测预报提供科学依据。选用2011~2012年长江三峡航道湖北宜昌至重庆宜宾段29个人工观测雾情台站资料和12个能见度观测仪资料,首先采用判别分析法寻找不同月份对雾情等级影响较大的气象因子,进一步采用通径分析法对量化的雾情资料分析地形地貌及气象因子对其的直接、间接影响程度。结果表明:常规气象要素对判断站点中雾和大雾的符合率在50%以上。风速、温度和湿度是影响秋末和冬季雾情等级的最主要气象因子。气象要素中的1 000 hPa湿度对能见度值的直接作用最大,通径系数为-0.518 2,而地理要素中山体与河面的落差对雾的滋生有间接作用。

INFLUENCE OF METEOROLOGICAL AND GEOGRAPHICAL FACTORS ON THE FOG IN THREE GORGES RESERVOIR OF THE YANGTZE RIVER

In this paper, the influences on fog (visibility) of the Yangtze River Three Gorges Reservoir from meteorological and geographical factors were studied. We provided a scientific basis for monitoring and forecasting visibility through the quantitative analysis. This article selected 9 artificial fog observation stations and 12 visibility observation instrument data from Yichang to Yibin in 2011-2012. First, the discriminant analysis method is used to find the key meteorological influencing factors in different months. The path analysis method is further used for the direct and indirect influence on the fog. The results showed that the fog compliance rate is more than 50% judged by conventional meteorological elements. Wind speed, temperature and humidity were found to affect the fog level in late fall and winter. Humidity at 1000 hPa directly affected the maximum visibility value with a path coefficient of -0.5182. Geographic features of the mountain and the river drop-on played an indirect role in the breeding of fog.