山东沂河中游段古河道形态特征与古流量  

Morphological Characteristics of the Paleo-channel and Paleo-discharge in the Middle Reaches of the Yihe River in Shandong Province

作　　者：曹光杰[1] 于磊 张学勤[1] CAO Guang-jie;YU Lei;ZHANG Xue-qin(School of Resources and Environment,Linyi University,Linyi,Shandong 276005)

机构地区：[1]临沂大学资源环境学院,山东临沂276005

出　　处：《地球学报》2019年第3期417-427,共11页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:41372182);山东省自然科学基金项目(编号:6011701512)联合资助~~

摘　　要：选择沂河中游段作为研究河段。根据芭山橡胶坝、北社橡胶坝、沂水县南王庄沂河大桥、336省道(S336)沂河大桥、沂南县澳柯玛沂河大桥的钻孔资料,绘制了5个断面沂河古河槽地质剖面图。在洙阳村附近沂河断面进行了电测法物探,根据钻探验证结果对物探测量的沉积层厚度进行了校正,绘制了洙阳村附近沂河断面古河槽地质剖面图。在洙阳村附近沂河两岸,澳柯玛沂河大桥附近沂河西岸,挖掘剖面采集了光释光(OSL)年代样品,在中国科学院青海盐湖研究所、南京师范大学光释光实验室进行了测试,获得了15个年代结果。选择澳柯玛沂河大桥附近剖面,用河相关系法计算了末次冰期最盛期(LGM)、晚冰期(约12 000 aB.P.)和全新世中期(约7 000 aB.P.)的古流量。结论认为,沂河现在河床下方的基岩河槽为末次冰期最盛期的古河槽,古河道纵比降较大;古河槽宽深比大,河槽宽浅,属于砾石河床分汊型;澳柯玛沂河大桥断面,末次冰期最盛期、晚冰期、全新世中期古流量分别约为17 m^3/s、20 m^3/s、30 m^3/s。With the middle reaches of the Yihe River as the study area,the authors drew stratigraphical cross sections of paleochannels based on the drilling data in five places which included the Bashan rubber dam,the Beishe rubber dam,the Nanwangzhuang Yihe Bridge,the S336 Yihe Bridge,and the Aucma Yihe Bridge.The authors applied electrical sounding method to the cross section of Yihe River near Zhuyang Village,and derived the depth of sediments which was further calibrated by the drilling records.Based on the corrected results of sediment depth,the authors drew the stratigraphical cross section of the ancient river channel at this place.Also,the authors dated 15 samples collected at the Yihe River banks near Zhuyang Village and the Acuma Bridge at the OSL laboratories in the Qinghai Institute of Salt Lakes of Chinese Academy of Sciences and Nanjing Normal University.Finally,the authors analyzed the configuration of the cross section at the Aucma Yihe River Bridge,and calculated river discharge at the Last Glacial Maximum(LGM),the Late Glacial Epoch(12 000 aB.P.),and the Mid-Holocene(7 000 aB.P.)using the discharge-sediment relation.It is concluded that the bedrock below the current river bed was the paleo-channel at the LGM whose stream gradient was higher.The ancient river took a braided form,which was characterized by a larger breadth-depth ratio,and wide and shallow river channels.At the cross section near the Aucma Yihe Bridge,the discharge at the LGM,the Late Glacial Epoch,and the Mid-Holocene were approximately 17 m^3/s,20 m^3/s,and 30 m^3/s,respectively.

关 键 词：沂河 古河道 古流量 末次冰期最盛期 晚冰期 全新世中期 

分 类 号：P343.1[天文地球—水文科学] P332.4[天文地球—地球物理学]