Extreme Precipitation Characteristics and Impacts of Urbanization in the Jianghuai Region from 1960 to 2018
The Jianghuai Region is situated at the boundary of the north and south rainfall belts in China.This region experiences frequent extreme precipitation events.Nevertheless,research on the characteristics,trends,and mechanisms of extreme precipitation in the context of urbanization is still insufficient.Based on the daily precipitation data from 305 stations in the study area from 1960 to 2018,this study analyzed the temporal and spatial characteristics of extreme precipitation,and compared the differences in extreme precipitation between urban and suburban stations to investigate the relative impacts of urbanization.To further explore the mechanisms behind the influence of urbanization,this study also compared the Clausius-Clapeyron scaling of urban and suburban stations.In addition,the differences in atmospheric stability and water vapor conditions between urban and suburban stations during typical extreme precipitation events were also analyzed by computing physical parameters.Land use types and nighttime lights data were used to rigorously differentiate urban stations from suburban stations.The results showed that:(1)Extreme precipitation in the study area exhibited distinct spatial variations.The area with a significant increasing trend in the extreme precipitation indices was concentrated in southern Jiangsu,northern Zhejiang,and Shanghai.(2)With the development of urbanization,there was a trend of shifting from negative to positive in the urban-suburban difference in extreme precipitation.Contribution of urbanization was positive for all the extreme precipitation indices,with a rate exceeding 35％for all cases.The data in urban stations exhibited a more sensitive response to temperature.(3)The analysis of physical parameters indicated that the influence of urbanization on extreme precipitation might be attributed to the warming effect of the urban heat islands.These heat islands triggered upward motion of air,increased atmospheric instability,and enhanced water vapor content,which facilitated convective processes and the occurrence of extreme precipitation.
extreme precipitationurbanizationurban heat islandJianghuai Region
NETL
NSTL
万方数据
