1966-2010年山东夏季极端降水事件特征分析

利用山东省117个测站19662010年夏季逐日降水资料集，分析夏季极端降水的时空变化特征。结果表明：1）夏季极端降水频次高值区位于鲁中及鲁东南等地，低值区主要位于鲁西北地区。极端降水强度高值区位于鲁东南地区，低值区主要位于鲁中及其北部地区。全省大部分地区极端降水频次和强度都存在增加趋势，尤其鲁中及其以南地区增加趋势明显。2）夏季极端降水可大致划分为鲁西北、鲁西南、鲁中及其北部、鲁东南、半岛5个区域，各区域极端降水频次和强度以准2~3 a的周期波动为主，鲁西北、鲁西南及半岛地区的极端降水频次和强度在年代际尺度上呈现出反向变化特征。各区域极端降水频次的长期趋势均为增加，而极端降水强度表现为鲁西北地区先增加后减小、其他地区先减小后增加的长期趋势。3）鲁西北、鲁中及其北部、半岛3个区域的夏季极端降水主要集中在7月下旬和8月上中旬，而鲁西南和鲁东南地区极端降水主要集中在7月中下旬。鲁西北和半岛地区极端降水开始时间有推迟的趋势，其他地区的为提前趋势。鲁西北和鲁西南地区的结束时间有提前趋势，其他地区的则为推迟趋势，但提前和推迟的趋势变化均比较微弱。

Characteristic Analysis of Extreme Precipitation Events over Shandong in Summer During 1966-2010

Using the 1966-2010 daily rainfall data of 117 stations in Shandong province,the spatial and temporal characteristics of extreme precipitation events in summer are investigated.Results show as follows.1) The frequency of extreme precipitation in summer is higher over middle and southeast of Shandong,and lower over northwest area.The intensity is higher over southeast area,and lower over the middle and its northern.An increasing trend of extreme precipitation frequency and intensity is found over most area of Shandong province,especially obvious over the middle area and its southern.2) Extreme precipitation in summer can be broadly divided into five regions:northwest,southwest,the middle area and its northern,southeast and peninsula,the frequency and intensity are mainly fluctuating in the quasi period of 2 to 3 years over all regions,but shows a reverse variation on the interdecadal scale in the northwest,southwest and peninsula.The frequency exhibits a long term increasing trend over all regions,but the intensity presents increasing firstly then decreasing trend in the northwest,and opposite in the other regions.3) Extreme precipitation in summer is mainly concentrated in late July and early and middle August over northwest,the middle area and its northern and peninsula area,but in middle and late July over southwest and southeast area.The beginning time postpones in northwest and peninsula,and moves up in other areas.The ending time moves up in northwest and southwest area,and postpones in other areas,but their trend variations are all relatively weak.