关键词: 暴雨, 频次, 周期, 相关系数

Abstract:

Based on the daily p recip itation data from 17 meteorological stations in Shijiazhuang area during 1972 - 2007, the climatic
characteristics and change rule of rainstorm occurred in Shijiazhuang were analyzed using the linear trend, the statistical method, the
power spectrum method aswell as theMann - Kendall test, and the relation between rainstorm days and high temperature dayswas ana
lyzed in light of the Pearson correlation coefficient. Results indicated that less rainstorm years are obviouslymore in the recent 36 years
in Shijiazhuang area. In seasonal distribution, rainstorm appeared in Ap ril to November butmainly concentrated in July and August; The
increase ( decrease) trend of rainstorm ismost remarkable in June (July) ; The rainstorm started to increase slowly from the second - ten
- day ofMay, and sharp increased in early July, then achieved the peak in earlyAugust; Rainstorm number increase ( decrease) trend
ismost obvious in late June ( late July). In spatial distribution, rainstorm days decreased gradually from northwest, southeast to interior
area in Shijiazhuang, and yearly mean rainstorm days in each station is above one day. Annual rainstorm days p resented increasing
trend in the west, north and northeast of Shijiazhuang area, but decreasing trend in the east, south and northwest aswell as urban dis
trict. There is four and three years periodical change in the number of rainstorm, and negative correlation between rainstorm days and
high temperature days in Shijiazhuang area.

Key words: rainstorm, frequency, period, correlation coefficient