西南地区的大气灾害及其时空变化规律

本地区为季风型、山地型和中纬多灾型的混合型多灾区，有七类３２种大气灾害、五类２８种大气灾链。在本区，受灾的面积和人口、死人、经济损失和灾种之最，皆推大气灾害，尤以旱灾类最重，其次是暴雨类。从主导的灾害类型、类、种的角度，将本地区划分成２大区、９区、１２亚区和５小区。近５００年来，大旱、大涝平均每２２．２年发生一次。

ATMOSPHERIC DISASTER IN SOUTHWEST REGION OF CHINA AND ITS CHANGE LAW WITH TIME AND SPACE

The Southwest China is a multiple disaster area of mixed disaster types of monsoon, mountain and disaster in middle latitude. There are 7 kinds and 32 species of atmospheric disasters, and 5 kinds and 28 species of atmospheric disaster chains in this region. The area and population to suffer disaster,death persons, disaster species and economic losses of atmospheric disasters are all highest in natural disasters in this region. The disaster or disaster chain of two kinds of drought and hard rain is especially most heavy in the atmospheric disasters. From view of main type, kind and species of disasters, this region is distinguished into 2 large districts,9 intermediate districts,12 subaltern districts and 5 little districts. In recent 500 years severe drought and waterlogging occurred in an average of one time each 22.2 years.