雷击地闪密度与雷暴日数的关系分析

根据美国卫星观测得到的我国各省区年平均总闪电资料并计算出各省区的年平均地闪密度(以下简称地闪密度);根据全国各省区220个站点的年平均雷暴日资料,按照<建筑物防雷设计规范>GB50057-94(2000年版)(以下简称<规范>)公式计算出全国各省区的地闪密度.比较两种方法得出的地闪密度,发现存在较大的差异,且不同区域差异变化很大.用单位雷暴日地闪密度概念,分析了我国各地单位雷暴日地闪密度的差异及其原因,指出单位雷暴日地闪密度能粗略反映与我国气候特征相适应的地闪密度的分布状况.进一步分析湖州市2007年人工观测和闪电定位仪观测的闪电资料,得到相同的结论.从而提出<规范>规定的地闪密度计算公式存在较大误差,应对其进行进一步的修订和完善.

The analysis on the relationship between density of ground lightning strokes and the number of thunderstorm days

According to the total lightning data of China's provinces among the lightning data obtained from U.S. satellite observations, we calculate the average ground lightning density. Simultaneously according to the annual average data of thunderstorm days in 220 spots around various provincial areas, the average ground lightning density of the provinces are calculated by the formula in 《Design code for protection of structures against lightning》(2000 version). Comparing the results of the two kinds of methods, it found that there were great differences, and the differences of some areas were significant. Putting forward the concept of the ground lightning density of thunderstorm day unit, analysing the difference between provinces all over the country and its reason, pointing out it could roughly reflect the distribution of the density of ground lightning adaptable to the characteristics of the China's climate, further analysing the lightning data of the artificial observation and lightning locator of Huzhou in 2007, we obtain the same conclusion. Thus the density of ground lightning calculated by the formula in 《Design code for protection of structures against lightning》(2000 version) should be further amended and improved.