摘要
利用北京1960~2014年日降水资料分析了北京地区极端降水时空变化特征。研究发现:各极端降水指数均呈下降趋势(CDD除外),表明北京降水有所减少、强度有所减弱;极端降水量在1990s有一显著突变点,日最大降水量(Rx1day)和5日最大降水量(Rx5day)在21世纪初有一显著突变点,其它指数无明显突变;极端降水日数(R25mm)与降水强度(SDII)具有相似的空间分布,表现为北京东北部至西北部值逐渐减小;R25mm与SDII大值区在城区出现概率较大,表明城区面临的灾害风险较高;北京各极端降水指数变化率空间分布表现出明显的差异性;各极端降水指数主要是由大中小三个不同尺度的周期相互嵌套。
Based on the daily precipitation data from 1960 to 2014 in Beijing, the temporal and spatial varia-tion characteristics of extreme precipitation in Beijing were analyzed. The study found that all ex-treme precipitation indices showed a downward trend (except CDD), indicating that Beijing’s pre-cipitation decreased and its intensity decreased;extreme precipitation had a significant mutation point in 1990s, daily maximum precipitation (Rx1day) and maximum precipitation on the 5th. The amount (Rx5day) has a significant mutation point at the beginning of the 21st century, and the other indexes have no obvious mutations;the extreme precipitation days (R25mm) and the pre-cipitation intensity (SDII) have similar spatial distribution, showing that the value from northeast to northwest of Beijing is gradually decreasing;the probability of R25mm and SDII large value ar-eas appearing in urban areas is large, indicating that the disaster risk faced by urban areas is high;the spatial distribution of the extreme precipitation index changes in Beijing shows obvious dif-ferences;the extreme precipitation indexes are mainly composed of three different large, medium and small. The periods of scale are nested with each other.
出处
《自然科学》
2019年第6期478-486,共9页
Open Journal of Nature Science
基金
成都信息工程大学本科教学工程项目(BKJX2019007,BKJX2019013,BKJX2019042,BKJX2019056,BKJX2019062,BKJX2019081,BKJX2019089,BKJX2019120和JY2018012)支持。
