1961—2014年石家庄地区降水量的时空变化特征

Spatial and temporal characteristics of precipitation in Shijiazhuang during 1961- 2014

利用石家庄地区5个代表站1961—2014年的逐日降水资料,采用多种统计分析方法,分析了石家庄地区降水量的时空变化特征,结果表明石家庄地区年降水量从20世纪70年代开始下降,80年代达到最低,90年代有所增加,但也没有明显的上升趋势,21世纪初又开始下降.20世纪70年代降水量的减少春季和秋季贡献最大,80年代降水量的减少和90年代降水量的增加主要是夏季的贡献.石家庄地区年降水量起伏较大,1963年降水量最多,为1 038.4 mm,2014年最少,仅为276.2 mm.近54年石家庄年降水量在波动中呈现下降趋势,线性趋势为-11.0 mm/(10 a),但下降趋势并不明显.石家庄北部年降水量呈上升趋势,市区及东部、南部和西部年降水量均呈下降趋势,变化趋势均不明显.近54年,石家庄春季降水量呈上升趋势,线性趋势为0.9 mm/(10 a),夏季、秋季和冬季降水量均呈下降趋势,线性趋势分别为-11.9,-1.1和-0.3 mm/(10 a),上升或下降趋势均不明显.夏季降水减少是导致石家庄年降水减少的主要原因.石家庄四季降水量变化趋势的空间分布具有明显的季节特征和区域特征.石家庄四季降水量均存在显著周期变化.

Based on daily precipitation data of five representative meteorological stations in Shijiazhuang area during 1961-2014,the spatial and temporal change characteristics of precipitation were analyzed by using a variety of statistical methods.Results show that annual precipitation in Shijiazhuang area begins to fall from the 1970 s and reaches the lowest in the 1980 s,then increases slightly in the 1990 s,and begins to decline in the 21 st century.The precipitation reduction in the 1970 s is mainly due to the rainfall decrease in spring and autumn,while the decrease in the 1980 s and slight increase in the 1990 s are mainly attributed to the precipitation variation in summer.The annual precipitation in Shijiazhuang area fluctuates obviously with the most precipitation of 1 038. 4 mm in 1963 and the least one of 276. 2 mm in 1965. In recent 54 years,the annual precipitation in Shijiazhuang decreases slightly with a linear trend of- 11. 0 mm /（ 10 a）. As for its spatial distribution,the annual precipitation increases in the north,and decreases in other parts of the city,yet without obvious trend.And for its temporal variation,the precipitation increases in spring with a linear trend of 0. 9 mm /（ 10 a）,while decreases in other seasons with the linear trends of-11. 9 mm /（ 10 a）,-1. 1 mm /（ 10 a）,-0. 3 mm /（ 10 a） for summer,autumn,and winter,respectively,all of which are not obvious.Generally,the reduction of annual precipitation in Shijiazhuang can be due to the precipitation decrease in summer; there were seasonal and regional characteristics in the spatial distribution of the precipitation change trends in four seasons in Shijiazhuang; and significant cycles exist in seasonal precipitation variation in Shijiazhuang.