福建省干旱概况及夏旱期间人工增雨条件分析

对福建省干旱的成因和干旱的环流形势进行了探讨,着重分析了夏旱期间人工增雨作业的天气形势、云状、回波特征及云顶温度等条件,结果表明福建省干旱的形成与大型环流形势、地形、地貌及土壤植被条件有关;平均而言,闽东南沿海干旱多于内陆地区;西太平洋副热带高压是夏季致旱的主要天气系统;夏季,西风槽前型、台风外围影响型、副热带辐合带型是进行人工增雨作业的有利天气形势,Sc、Cb、Cu云都有一定的人工增雨作业条件,其中降水时长1～5 h,过程雨量1.0～5.0 mm的云是旱季作业比较适合的作业云.这些结果为开展人工增雨作业提供理论依据,达到解除或缓解干旱的目的.

GENERAL SITUATION OF DROUGHT AND CONDITIONS OF ARTIFICIAL RAINFALL IN SUMMER DROUGHT PERIOD IN FUJIAN PROVINCE

The formation causes and the circulation patterns of droughts in Fujian Province are discussed, and the weather type, cloud form, the characteristics of echoes and temperature of cloud top for the artificial rainfall in the summer drought period are analyzed. The results show that the formation of droughts is correlated with circulation patterns, landform, soil and vegetation. On an average, the droughts in the southeastern inshore of Fujian are more than those in the northwestern inland. The western Pacific subtropical high is the main weather system resulting in drought in summer. Some weather patterns are favorable for artificial rainfall operation in summer. The cumulonimbus, cumulus and stratocumulus, to some extent, are advantageous to artificial rainfall operation, and the clouds with raining time being 1 to 5 hours and rainfall being 1.0 to 5.0 mm are favorable for the seeding operation in the drought season. The results provide the theoretical basis for the artificial rainfall operation.