High resolution records of flood deposition in the mud area off the Changjiang River mouth during the past century

IOCAS-IR

	High resolution records of flood deposition in the mud area off the Changjiang River mouth during the past century
	Hu G(胡刚); Li AC(李安春); Liu J(刘健); Xu G(徐刚); Mei X(梅西); Kong XH(孔祥淮)
发表期刊	Chinese Journal of Oceanology and Limnology
ISSN	0254-4059
	2014-07-15
出版年	2014
卷号	v.32 期号:04 页码:175-186
文献类型	CNKI期刊论文
摘要	This paper presents a paleoflood study to determine the flood frequency of the Changjiang River, based on core cj0702, taken from the Changjiang River subaqueous delta. We identified flood deposits by means of high-resolution grain-size variation, sensitive population, geochemical indexes and magnetic susceptibility. The core covers a time span of 120 years by 210 Pb dating and was sampled at 1–2 cm intervals. Grain size, geochemical elements, and physical parameters were analyzed. The results indicate that the sediment of the core is mainly composed of silt and clay, as well as groups of interbedded silt, clay silt, and clay. Vertically, the grain size pattern was controlled by seasonal variations in water discharge and by the sediment input in winter from the abandoned Huanghe River delta. River flooding caused extreme values in all our measured parameters. We identified more than 20 flood events that occurred since 1887 using the physical parameter analysis method. The environmentally sensitive component of sediment grain size(14.32–96.39 μm) contribution>30%, Zr/Rb ratio>1.5, and magnetic susceptibility>16 were selected as the criteria for flood identification generally. We also found that floods that had taken place in the upstream, midstream, or downstream parts of the river were clearly identified by these indexes while the large-scale floods that covered the whole drainage area did not leave clear indications in the sediment record. This study for identification of flood events is of great significance for understanding hyperpycnal current sedimentation as well as for forecasting of floods.
关键词	high resolution grain size flood deposition mud area the Changjiang River
CNKI专辑号	A;
CNKI专辑名称	基础科学;
CNKI专题号	A010;A011;
CNKI专题名称	海洋学;地质学;
分类号	P736.21
收录类别	中科院核心 ; 中科院扩展
语种	英文;
资助项目(基金）	Supported by the National Natural Science Foundation of China(Nos.41206073,41376079,41206051,41206052) ; the China Geological Survey(Nos.1212010611401,200900501)
文献类型	CNKI期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/190392
专题	中国科学院海洋研究所
作者单位	1.KeyLabofMarineGeologyandEnvironment,InstituteofOceanology,ChineseAcademyofSciences 2.KeyLabofMarineHydrocarbonResourcesandEnvironmentalGeology,MinistryofLandandResources 3.UniversityofChineseAcademyofSciences
推荐引用方式 GB/T 7714	Hu G,Li AC,Liu J,et al. High resolution records of flood deposition in the mud area off the Changjiang River mouth during the past century. 2014.