长白山白河千年来气候环境变化与河流沉积

The Climatic Environmental Change and Fluvial Deposits Since 1000 Years in Baihe River of Changbai Shan,Jilin Province

气候变化是近年来全球变化研究关注的热点内容,尤其是气候异常给人类带来的灾难性损失,是山区发生灾害地貌的主导外因。对长白山松江水文站阶地剖面的粒度参数和孢粉进行分析,结合AMS14C测年数据并与历史记录相校验,重建该区的气候环境演化特点与河流沉积物的相变过程。结果显示,研究区自千年来经历了3次明显的气候波动,即800—686 a B.P.气候凉湿;686—428 a B.P.气候暖干;428 a B.P.—至今气候以凉湿为主,但有明显向温暖偏干方向发展的趋势,与近几年全球变暖相一致。剖面沉积结构显示,在几百年时间内发生三期河床波动,与气候的快速转变存在明显的对应关系,加强上游河流的水土保持工作并注意对两岸采石与就地取沙的管理。

A continuous fluvial sedimentary profile,Songjiang Hydrological Station is located near Songjiang Town,Jilin province.The environmental and fluvial deposits change indexes are related to the grain size,pollen analysis,with the AMS14C dating.Compared with the definite historical climate records,the climatic environmental change since 1000 years in the research region was discussed.The results show that the climate fluctuated in three stages,that is,the climate was cool and wet during 799~686 a B.P.,warm and dry during 686~428 a B.P.,wet and cool during 428 a B.P.-present.However,it has the tendency of becoming warm and dry.The results reflect that the climate change in different stages according with the historical records.Sedimentary profile shows that Baihe river bed has undergone three time fluctuation.The water conservation should be undertaken to protect from the loss of river sand and gravel.