石家庄市不同等级降水日数的时空分布特征

利用1972—2007年石家庄市17个测站逐日降水资料,采用线性趋势法和Mann-Kendall突变检验法,分析了近36 a石家庄市不同等级降水日数时空分布特征和变化规律。结果表明：石家庄市年总雨日数和不同等级降水日数均呈减少趋势,暴雨日数减少趋势最不明显;年总雨日数发生了突变,突变年份为1992年;20世纪90年代后,降水有向极端化发展的趋势。在空间分布上,石家庄市年总雨日数和不同等级降水日数自西北、东南向中部地区逐渐减少,西北部山区和东南部平原存在两个多雨日中心和多暴雨中心;各站年总雨日数和小雨日均呈显著减少趋势,北部、西北部和东南部地区减少趋势相对更显著,其他等级降水事件日数大多数观测站也呈减少趋势,但减少速率相对较小。

Temporal-spatial distributions of different level precipitation days in Shijiazhuang,Hebei province

Based on the daily precipitation data from 1972 to 2007 in 17 weather stations of Shijiazhuang, the temporal and spatial distributions of different level precipitation days were analyzed by linear trend method and Mann- Kendall mutation testing during recent 36 years. The results show that total precipitation days and different level precipitation days decrease obviously, and the decreasing tendency of heavy rainstorm days is the weakest. An abrupt change of annual total precipitation days occurs in 1992, and precipitation evolves to the extreme since 1990s. Annual total precipitation days and different level precipitation days decrease from the northwest and the southeast to the middle areas. There are rainy day center and rainstorm center in the northwest mountains areas and southeast plain. Annual total precipitation days and light rain days decrease obviously in each weather station, especially in the north ,northwest and southeast areas. On the other hand, other level precipitation days also decrease in most weather stations, while the speed of decrease is relative small.