Analysis of Rainstorm Characteristics and Causes in Xishui County of Guizhou Province
This paper aims to reveal the spatio-temporal distribution characteristics of heavy precipitation weather in Xishui County,Guizhou Province,under the background of frequent extreme weather.Based on daily precipitation data of the national basic meteorological station in Xishui County during 1959-2022 and daily precipitation data of 24 township stations from 2010 to 2022,the spatial and temporal distribution characteristics and causes of heavy rainfalls in Xishui County are analyzed by using statistics and spatial interpolation methods.The results show that heavy rainfalls in Xishui County mostly occur in the windward slopes of Xishui Valley and Chishui Valley as well as the eastern trumpet topography area,more in the north and less in the south.The annual regional rainstorm days is in a ＂unimodal＂pattern.The monthly variation of regional rainstorm has obvious normal distribution characteristics,mainly appearing from May to September,accounting for 94%.The monthly distribution of regional heavy rainstorm days is in a ＂double peak＂pattern,and the peak value is in June and August.The heavy rainfall in Xishui County has obvious diurnal variation characteristics,and the nighttime rainstorm accounts for 81.1%.The regional rainstorm processes are mainly concentrated in 19∶00-06∶00,accounting for 76.9%.There are torrential rains from spring to autumn in Xishui,and the maximum frequency of heavy rain days moves from west to east,of which summer has the most rainstorms,taking up 69%.The influence systems that cause regional heavy rain weather are divided into four types:low vortex shear type,cold front low trough type,Meiyu front type and typhoon peripheral type.The low vortex shear type generates rainstorm most,accounting for 77.3%.In summary,the spatial distribution of rainstorms in Xishui County is more in the north and less in the south.The regional heavy rain mainly occurs from May to September,with obvious characteristics of nighttime rainfall.The research results of this paper could provide a reference for heavy rain and severe weather forecast and meteorological service in Xishui County.
rainstorm characteristicscause analysisXishui County
NETL
NSTL
万方数据
