摘要
基于2012—2021年5—9月华北五省的逐日降水资料和台站地形高度数据,统计分析了华北全区及各子区域极端降水事件的降水量及其强度和频次的时空分布特征;并运用地理加权回归(GWR)模型分析得到极端降水事件的降水量、强度及频次与海拔高度之间的关系。结果表明:1)华北区域极端降水量的时间变化均呈多波动特征且区域差异性显著,太行山以西高原和以东平原降水频次多、波动明显且强度较弱,太行山南段以南平原降水频次少、变化平缓而强度明显偏强。2)极端降水量的空间分布呈现南北少、中间多的型态分布,降水量大值区分别位于燕山东南侧和太行山南段晋冀豫三省交界处;极端降水高频站点主要聚集在晋东南地区;日最大降水量超过300 mm的站点主要集中在太行山脉和燕山山脉与华北平原的过渡地带。3)华北区域38°N以北,极端降水量、降水频次、强度和日最大降水量均随海拔高度的升高而减小;38°N以南,山西南部临运地区降水量随海拔高度的升高而显著增加。由于降水频次和强度与地形均存在正相关而导致,太行山附近降水量随海拔高度的升高而减小的贡献主要在于降水强度而非降水频次。
In the context of global warming,frequent extreme precipitation events pose a serious threat to people s livelihoods,production,and the economic development of society.The topography of North China(NC)is complex and diverse,and the distribution of precipitation is inconsistent due to the influence of terrain.In particular,there are significant geographical differences in the intensity and frequency of extreme precipitation.This study systematically analyzed the spatiotemporal distribution characteristics of precipitation amount,intensity,and frequency of extreme precipitation events in NC and its subregions.The analysis utilized daily precipitation data and station topographic height data from five provinces between May and September,spanning the period of 2012 to 2021.By calculating the 95th percentile of daily precipitation at each station throughout the study area,regional extreme precipitation events in NC were filtered.Geographically Weighted Regression(GWR)models were used to investigate the relationship between precipitation,the intensity and frequency of extreme precipitation events,and altitude.The results indicate that extreme precipitation in NC has exhibited multiple fluctuations over time,with significant regional variations.The plateau to the west of the Taihang Mountains and the plains to the east of the Taihang Mountains experienced more frequent yet fluctuating and low-intensity precipitation,while the plains to the south had less frequent yet gradually changing and significantly stronger precipitation.The spatial distribution of extreme precipitation indicates lower levels in the southern and northern regions and higher levels in the central region,influenced by factors such as topography.The extensive precipitation areas are located in the southeastern part of the Yanshan Mountains and at the junction of Shanxi,Hebei,and Henan Provinces.The average annual precipitation of the above two regions exceeds 200 mm,and the precipitation of some stations exceeds 280 mm.During extreme precipitation events,heavy rainfall often occurs at each weather station,indicating a tendency for clustering.The stations with the highest frequency of heavy precipitation are mainly located in the southeastern part of Shanxi Province.Moreover,stations that recorded maximum daily precipitation of over 300 mm are mainly concentrated in the transition zone between the Taihang and Yanshan Mountains,as well as the NC Plain.The diverse impact of regional topographies on precipitation intensity and frequency leads to significant variations in the characteristics of extreme precipitation,precipitation frequency,intensity,and daily maximum precipitation with altitude in the northern and southern parts of the NC area,which is divided by 38°N.In the northern part of NC,the extreme precipitation,frequency,intensity,and daily maximum precipitation all decrease with the increase of altitude.There are significant regional differences in the variation of precipitation south of 38°N with altitude,and the variables that dominate this difference vary from region to region.The significant increase in precipitation in the Linfen and Yuncheng areas of southern Shanxi with increasing altitude is due to the positive correlation between precipitation frequency and intensity with terrain.The main factor contributing to the decrease in precipitation near the Taihang Mountains with increasing altitude is the intensity of precipitation,not its frequency.
作者
马丽
武永利
董春卿
郝婧宇
李娜
MA Li;WU Yongli;DONG Chunqing;HAO Jingyu;LI Na(Shanxi Meteorological Observatory,Taiyuan 030006,China)
出处
《大气科学学报》
CSCD
北大核心
2024年第3期438-449,共12页
Transactions of Atmospheric Sciences
基金
中国气象局创新发展专项(CXFZ2022J016)
中国气象局复盘专项(FPZJ2023-017)
山西省科技厅面上项目(202203021211080)。
关键词
华北地区
暖季极端降水
时空特征
GWR模型
地形
North China
extreme precipitation events in the warm season
space time characteristics
geographically-weighted regression model
topography
作者简介
联系人:武永利,E-mail:wu_yongli@sina.com。
