湖南极端干旱气候时段人影作业潜力分析

利用湖南97个气象观测站逐日综合气象干旱指数、逐日降水量和湖南天气气候分区,研究湖南极端干旱特征和极端干旱时段内人工影响天气增雨潜力,结果表明:①湖南极端干旱期有相当的增雨潜力,各个分区的极端干旱频次和大气可降水量年代际变化除70年代外均呈现为北少南多的特点。②极端干旱时段内各分区年均可增雨日数主要表现为月际差异,可增雨日数主要集中在8-10月,各分区区域差异较小,各分区在伏旱期的可增雨日数大约占伏旱期的16%~20%。③湖南极端干旱按照出现的季节分类有11种,频次最高的是夏秋连旱,同时夏秋连旱的可增雨日数最多。

Potential Analysis of Rain Enhancement Operation in Extreme Arid Periods in Hunan Province

Using the daily meteorological drought index, daily precipitation and Hunan weather/climate regionalization data of 97 meteorological stations in Hunan, the extreme drought characteristics of Hunan and the potential of weather modification during extreme drought periods are studied. The results show: Hunan has considerable potential for rainfall enhancement during the extreme drought periods. The extreme drought frequency and the inter decadal variation of atmospheric precipitation in each subarea are characterized by the characteristic of less in North and greater South. The annual number of days in which rainfall may be enhanced in each area during extreme drought periods is mainly characterized by monthly differences, which is mainly concentrated from August to October. The small difference in each partition area and the number of rain increasing days in each period in the drought period is about 16% to 20% of the drought periods. There are 11 types of extreme droughts in Hunan according to the occurrence season. The summer autumn continuous droughts have the highest occurrence frequency, which have the highest number of days in which rainfall may be enhanced.