摘要
利用长沙、株洲、湘潭城市群9个气象站1961—2012年降水资料,采用百分位法确定城市群各站春、夏、秋、冬四季极端强降水阈值,分析城市化缓慢发展期与快速发展期城市群四季极端降水变化特征。结果表明:(1)各站极端降水阈值、日数与强度无明显的地域差异,影响城市群各站极端降水的天气气候系统基本一致。(2)相对于城市化缓慢发展期,快速发展期偏北区域站点春、夏季极端降水日数减少,而偏南区域站点则增加;前后两个时期,春、秋、冬季极端降水强度变化各站较为一致,但夏季南北区域其变化存在明显差异。(3)从城市化缓慢发展期到快速发展期,城市群夏季极端降水距平分布发生明显变化,即北部夏季极端降水由正距平转为负距平,而南部则由负距平转为正距平。
Based on the daily precipitation dataset of 9 weather stations in the Changsha-Zhuzhou-Xiangtan urban agglomeration from 1961 to 2012, we use the 95th percentile to define the thresholds of extreme precipitation at the various stations in this agglomeration for spring, summer, autumn and winter, and then assess the variation characteristics of extreme precipitation at all seasons between slowly expanding pe-riod and rapidly expanding period of urbanization. The results are as follows. (1) There are no significant spatial differences in threshold, fre-quency and intensity of extreme precipitation;Synoptic systems that cause extreme precipitation are consistently similar at the various sta-tions. (2) Compared to the slowly expanding period of urbanization, in the rapidly expanding period the extreme precipitation days during spring and summer decreased in the northern stations, but increased in the southern stations. Between slowly and rapidly expanding periods, there are identical variations of extreme precipitation intensity in spring, autumn and winter at the various stations, although there are clear difference in summer in northern and southern parts of the urban agglomeration. (3) From slowly expanding period to rapidly expanding peri-od, distribution of extreme precipitation anomalies at the various stations in the urban agglomeration vary clearly in summer. Summer extreme precipitation anomalies at the stations in the northern urban agglomeration vary from positive to negative, but from positive negative to positive in the southern stations.
出处
《暴雨灾害》
2015年第2期191-196,共6页
Torrential Rain and Disasters
基金
国家环保公益性行业科研专项子课题"长株潭地区气象要素及大气特征研究"(201109005)
湖南省气象局2014重点课题"城市化进程对长株潭地区大气与环境的影响"
关键词
长株潭城市群
城市化
极端降水
百分位法
Changsha-Zhuzhou-Xiangtan urban agglomeration
urbanization
extreme precipitation
percentile
