摘要
利用广东省86个地面气象站近50年(1951-2000年)逐日平均气温和最低气温资料,采用针对冬季经济林果的寒害指标,统计分析了近50年冬季寒害的特征。分析得出:(1)广东冬季寒害频数北多南少,各地平均年均1次,其中严重寒害近4成,严重寒害中又以降温型亚类Ⅲ最为典型,占6成以上。(2)寒害过程降温幅度平均达13.6℃,且越往南越大;过程最低气温平均2.6℃,高于冻害临界值0℃;寒害过程降温平均历时4d。(3)寒害分布于10月末至3月底,其中12月到1月累计占85%,月际分布大致呈以1月为峰值的单峰型;亚类Ⅲ12月和2月多于1月,呈双峰分布。(4)1980年是广东冬季气温变化的分水岭,寒害年均综合频数前30年多(160站次),后20年少(96站次)。(5)近50年广东冬季寒害年代际变化特征为:50,60,70年代逐渐增强,80年代迅速减弱,90年代有所回升(依然弱于50年代),年代际寒害由强到弱顺序为:70年代,60年代,50年代,90年代和80年代。
Using day-by-day average temperature and extreme low temperature data in recent 50 years(from 1951 to 2000) of the 86 weather ground stations in Guangdong Province,introducing a cold disaster index suitable for economic fruit trees growing in winter,the characteristics of cold damage in winter of recent 50 years are analyzed and the conclusions are reached as follows:(1)The annual average of frequence of cold damage in winter of all stations in Guangdong is about once a year and it is higher in northern area than southern area; the severe type cold damage occupies about 40%, the most representative sub-type Ⅲ occupies 60% in the severe type.(2)Average extend of temperature droping down during the cold damage course is 13.6℃,and it is higher in southern area than in sorthern area;the average extreme low temperature during the course is 2.6℃, which is hither than the freezing critical-0℃;temperature droping course lasts 4 days in average.(3)cold damage mostly occurs from late Oct. to late Mar., the total frequence from Dec. to Jan.amounts to 85% of all, monthly distribution is one-peak type with the highest value in Jan.,the frequences of sub-type Ⅲ in Dec. and Feb. are highter than that in Jan.,which shows a double-peak type of monthly distribution.(4) the AD 1980 is a watershed of cold damage in winter in Guangdong,yearly synthesis frequence in 30 years before 1980 is higher than that in 20 years after 1980.(5)the decades changing character of the cold damage in winter in Guangdong Province is: it becomes severer and severer in 1950s,1960s and 1970s,weaker rapidly in 1980s,and rise in the 1990s(but still weaker than 1950s).The sequence from the most severe to the weakest is: 1970s, 1960s, 1950s, 1990s and 1980s.
出处
《自然灾害学报》
CSCD
北大核心
2004年第4期121-127,共7页
Journal of Natural Disasters
基金
国家"十五"科技攻关项目(2001BA509B1)
关键词
广东
寒害
50年
Guangdong
cold damage
50 years
