摘要
为揭示长江流域气象干旱与降水时空分异特征之间的关系,利用长江流域39个分区1960~2019年的月降水数据,先采用标准化降水指数方法构造了长江流域气象干旱指数系列;然后根据游程理论对干旱指数系列进行干旱过程识别,并由此提取干旱次数、干旱历时、干旱烈度、干旱频率等干旱特征变量;最后引入季节性指数,探讨了干旱特征变量与降水季节性之间的关系。结果表明,长江流域降水具有显著的季节性,降水季节性指数自西向东逐渐减少。干旱特征变量与降水季节性指数之间在空间上存在较好的线性关系,即降水季节性越弱的区域,干旱越严重(干旱历时越长、干旱烈度越大)。这可能归因于降水季节性较弱区域春、冬两季干旱发生频率较高。该研究可为长江流域气象干旱成因机制的深入研究提供一定参考。
In order to reveal the relationship between the meteorological droughts and the spatio-temporal variations of precipitation in the Yangtze River Basin(YRB),the meteorological drought index series of the YRB were firstly calculated using the monthly precipitation data from 39 sub-regions across the whole basin during 1960-2019 by the standardized precipitation index(SPI)method.Drought characteristic variables including number of drought events,drought duration,drought magnitude and drought frequency were then extracted from the SPI series using the run theory.Finally,the seasonality index method was used to analyze the relationship between drought characteristics and seasonality of precipitation.The results show that the seasonality of precipitation over the whole YRB is significant,and seasonality index of precipitation decreased from west to east.There are significant linear correlations between seasonality index of precipitation and drought characteristic variables,i.e.,the sub-regions with the weaker seasonality of precipitation has experienced more severe drought events of long duration and high magnitude,which may be attributed to high drought frequency in spring and winter.This study provides some references for further study on the causal mechanism of meteorological droughts in the YRB.
作者
李帅
杜涛
LI Shuai;DU Tao(China Three Gorges Corporation,Yichang 443133,China;Bureau of Hydrology,Changjiang Water Resources Commission,Wuhan 430010,China)
出处
《水电能源科学》
北大核心
2021年第8期1-5,共5页
Water Resources and Power
基金
国家重点研发计划(2019YFC0408903,2016YFC0402306-01)。
关键词
气象干旱
降水季节性
长江流域
干旱特征变量
标准降水指数
季节性指数
meteorological droughts
seasonality of precipitation
Yangtze River Basin
drought characteristics
standardized precipitation index
seasonality index
