摘要
对长江三角洲地区埋藏古树、泥炭以及海相贝壳测年资料作了分析,结果表明,长江下游地区1万年以来古洪水的发生与气候变化有着密切的联系,洪水频繁发生的时期往往也是气候转型期。由于长江三角洲地区地势低平这一地貌特征使海面变化对于研究区洪水发生有着重要的影响,气候变化导致的海面上升对长江下游河段径流的顶托作用导致河流上溯以及地面排水不畅,导致洪水发生频率加大以及洪水灾害程度的加强,以至于出现"小水大灾"的现象。长江三角洲地区古洪水发生频率与美洲地区古洪水发生频率的对比研究结果表明,长江三角洲地区乃至整个长江流域在大的气候变化趋势上与全球其他地区可能有着遥相关关系,既有全球气候变化的特点,同时又具有区域响应的特征。
Comprehensive collection and further study performed on the 14C dating materials of buried paleotrees, peat and shell ridges indicate that there exists close relationship between the flooding occurrence and the climatic changes in the Yangtze River Delta, and the frequentlyoccurring flooding periods are corresponding to the climatic transition periods. Lowlying geomorphic features of the study region have more sufferings from high sea level caused by the flooding events in the study region. High sea level causes the surface water discharge more difficult during the wet climatic periods, leading to more serious flooding inundation and higher frequency of flooding occurrence in the study region. Comparison study performed on the paleoflood occurrence in the Yangtze River Delta region with that in the America indicates that characteristics of the climatic changes in the Yangtze River Delta region, and even in the whole Yangtze River drainage basin, are similar to those in other places in the world, but the study region has its own local characteristics of climatic changes. Also, our study indicates that there exist close relationships between the flooding occurrence and the El Nino event,and further study remains to be done to make clear the relations, which is practically and theoretically meaningful in the future forecast of the flooding events occuring in the study region.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2003年第3期11-15,共5页
Marine Geology & Quaternary Geology
基金
中国科学院知识创新工程重大方向项目(KZCX3 SW 331)
国家自然科学基金资助项目(40271112)
湖北省涝渍灾害与湿地农业重点实验室开放基金项目
关键词
洪水
气候变化
气候转型事件
全新世
长江三角洲
climatic changes
paleoflooding occurrenc
6 000 aBP
the lower reaches of the Yangtze River
