粤港澳地区1961—2020年极端降水事件的空间特征

The Spatial Characteristics of Extreme Precipitation Events on Guangdong,Hong Kong and Macao from 1961 to 2020

采用Mann-Kendall检验、Theil-Sen s斜率估计和相关性分析法,基于粤港澳地区38个气象站点近60 a的日降水量,分析了研究区内年平均降水量、不同等级降水以及极端降水指数的空间变化,揭示了粤港澳地区的降水特征及极端降水事件的空间演变规律。研究结果表明:粤港澳沿海地区的年均降水量较大,有26个站点的年降水量表现出增加趋势,但澳门站的年均降水量有下降趋势,变化率为为-24.1 mm/10 a;粤港澳山区小雨和中雨的占比较大,而平原地区大雨和暴雨的占比较大,香港天文台站的暴雨占比最大,达到2.45%;粤港澳地区有15个站的CDD指标呈显著增加趋势,表明在过去60 a干旱情势可能会逐渐增加,珠江三角洲河口地区与粤东沿海地区发生极端强降水的趋势有所降低;CDD与Rx1day、Rx5day、R95pTOT、R99pTOT均呈显著正相关,而与PRCPTOT呈负相关,表明粤港澳地区持续干旱天数的增加不仅会导致年总降水量减少,还与极端降水量的增加有关。

Studying the spatial evolution patterns of extreme precipitation events in the Guangdong-Hong Kong-Macao Greater Bay Area is of great significance for flood control and disaster reduction,as well as responding to drought events in changing environments.This article uses Mann Kendall test,Theil Sen s slope estimation,and correlation analysis to analyze the spatial changes of annual average precipitation,different levels of precipitation,and extreme precipitation index in the study area based on the daily precipitation of 38 meteorological stations in the Guangdong,Hong Kong and Macao region over the past 60 years.It reveals the characteristics of precipitation in the Guangdong Hong Kong Macao region and the spatial evolution of extreme precipitation events.The research results show that the average annual precipitation in the coastal areas of Guangdong,Hong Kong,and Macao is relatively high,with 26 stations showing an increasing trend in annual precipitation.However,the average annual precipitation at the Macao station shows a decreasing trend,with a change rate of-24.1 mm/10a.The proportion of light rain and moderate rain in mountainous areas of Guangdong,Hong Kong and Macao is relatively large,while that of heavy rain and rainstorm in plain areas is relatively large.The proportion of rainstorm at the Hong Kong Observatory is the largest,reaching 2.45%.The CDD index of 15 stations in Guangdong,Hong Kong and Macao shows a significant increase trend,indicating that the drought situations may gradually increase in the past 60 years,and the trend of extreme heavy precipitation in the estuary area of the the Pearl River Delta and the coastal area of eastern Guangdong has decreased.CDD is significantly positively correlated with Rx1day,Rx5day,R95pTOT,and R99pTOT,while negatively correlated with PRCPTOT.The increase in sustained drought days in the Guangdong Hong Kong Macao region not only leads to a decrease in total annual precipitation,but also is related to an increase in extreme precipitation.