福建省近50年旱涝时空特征演变——基于标准化降水指数分析

Evolution of spatiotemporal characteristics of flood and drought in Fujian Province for recent 50 years:an SPI-based analysis

旱涝灾害是影响我国的主要气象灾害之一。利用福建省60个气象站1960-2006年逐月降水观测资料,采用标准化降水指数(SPI)、M ann-Kendall检验、正交经验分解函数和旋转经验正交分解函数等方法,分析了近50年福建省旱涝时空变化的特征。结果表明:(1)福建省近50年总体上向涝的趋势发展,SPI指数在20世纪60年代先升后降,至70年代中后期开始上升,80年代初发生短暂下降,此后持续上升,上升趋势一直持续到21世纪。(2)旱涝呈现阶段性变化,1960-1972年、2000-2005年为干旱发生频繁的阶段;20世纪70年代中后期、90年代则为雨涝频繁的阶段。(3)根据旱涝特征差异,福建省可划分为闽东南沿海、闽北、闽东与闽西等4大区域,4个区域总体上与全省具有相对一致的旱涝趋势,但在某些时段南北方向上的不同区域之间存在差异。(4)福建省20世纪70年代中期和2000年以后旱涝变率最大,20世纪80年代初变率最小,且4个区域也表现出类似的特征。

Flood and drought disasters are the main meteorological disasters in China. This paper applies standardized precipitation index （SPI）, Mann -Kendall test, EOF and REOF to explore the spatio -temporal characteristics of flood and drought in Fujian Province based on the observed monthly precipitation data of 60 meteorological stations from 1960 to 2006. The results show that ： （ 1 ） There is a trend toward flood in Fujian Province for the recent 50 years on the whole. SPI firstly increased and then decreased in the 1960s, and it was on the increase since the mid 1970s, while there was a short decrease in the 1980s, and then it increased continuously until the 21st century. （2） Flood and drought disasters have stage characteristics, i. e. droughts were frequent during the periods 1960 -1972 and 2000 -2005, while floods were severe and frequent during mid to late 1970s and in 1990s. （3） Fujian Province can be divided into four regions, coastal area in southeast Fujian, north Fujian, east Fujian, and west Fujian, which have similar-trends of flood and drought disasters to the whole province. However, there are disparities between south and north regions during some periods. （4） The greatest variation of flood and drought occurred in the mid 1970s and the years after 2000, while weakest variation occurred in the early 1980s. Moreover, the four regions have similar characteristics to the whole province.