基于SPI的京津冀地区旱涝时空变化特征分析

SPI based analysis on characteristics of drought-flood spatial-temporal variation of Beijing-Tianjin-Hebei Region

以京津唐地区及周边地区37个气象站点1961-2010年逐月降水为基础资料，以地理信息系统技术为处理平台，结合滑动t检验、SPI指数（SPI，standard precipitation index）方法和空间插值伪形（inverse distance weighting）等，分析京津冀地区年降水量趋势性、突变性、以及各地区旱涝发生等级、发生频率、旱涝发生频率的空间分布特征、降水突变点前后时段各地区旱涝特性的转变。结果表明：（1）近五十年，京津冀地区北部降水减少，南部降水增加，整体呈减少趋势，降水在1996年前后两时段变化剧烈；（2）北京、承德、唐山为旱涝交替高发区，秦皇岛、石家庄为洪涝高发区，张家口为干旱易发区；（3）变化期和基准期前后比较，各地区旱涝特征变化显著，整体的趋势是干旱形势加重，洪涝趋势减弱。

Based on the monthly rainfall data from 1961 to 2010 obtained from 37 meteorological stations within Beijing-Tianjin- Hebei Region and its surrounding areas, the trend and mutation of the annual precipitation in the region as well as the grade and frequency of the drought-flood occurrence, the spatial-temporal distribution characteristics of the frequency of the drought-flood occurrence of all the areas and the changes of the drought-flood characteristics therein are analyzed herein in combination with the methods such as the Sliding T-test, SPI（ standard precipitation index） and IDW（ inverse distance weighting）, etc. by taking GIS as the treatment platform. The resuh shows that（ 1 ） In recent 50 years, the precipitation in Beijing-Tianjin-Hebei Region decrea- ses in the north and increases in the south with the trend of decrease on the whole, while it is drastically changed in the two peri- ods before and after 1996; （2） Beijing, Chengde and Tangshan are the high occurrence areas of alternate drought and flood, while Qinhuangdao, Shijiazhuang are the flood and waterlogging-prone areas and Zhangjiakou is the drought-prone area as well; （ 3 ） through the comparisons made before and after the changing periods and reference periods, the changes of the characteristics of droughts and floods occurred in all the areas are significant and the overall trend of the drought situation are aggravated with a trend of the alleviation of flooding and waterlogging.