Anthropogenic influence on sedimentation during the last 100 years inferred from magnetic properties in the Changjiang Estuary, China
Anthropogenic influence on sedimentation during the last 100 years inferred from magnetic properties in the Changjiang Estuary, China
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DOI：
10.1007/s12665-013-2254-x
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发表时间：
2013-01
影响因子：
2.8
通讯作者：
Yonghong Wang;T. Oguchi;P. Ridd;H. Shen
中科院分区：
文献类型：
--
作者：
Yonghong Wang;T. Oguchi;P. Ridd;H. Shen
通过对长江口近百年来的沉积记录分析，探讨了自然和人为因素对长江口地貌动力演变的影响。通过对两个重力岩心的磁性、沉积物粒度、化学元素和210Pb年代学分析，推断沉积作用。结果表明，近百年来，沉积学指标，特别是磁性和微量元素变化显著，并在1960年前后发生突变。这种突然的变化可能是由于填海导致上游河口河段变窄而导致水动力能量减少的结果。长江流域其他地区的研究表明，长江中上游土壤侵蚀引起的陆源输入的增加以及钢铁产量的增加也可能产生重大影响。
A 100-year sedimentary record in the Changjiang Estuary was examined to elucidate natural and anthropogenic influences on the morphodynamic evolution of the estuary. Two gravity cores were acquired and their magnetic properties, sediment size, chemical elements and210Pb geochronology were analyzed to infer the sedimentation. The results indicate that these sedimentological indexes, especially magnetic properties and trace elements, changed significantly during the last 100 years, with an abrupt change occurring at around 1960. This abrupt change is likely the result of a reduction in hydrodynamic energy caused by the narrowing of an upstream estuary reach due to reclamation. An increase of terrigenous input, due to soil erosion in the upper and middle reaches of the Changjiang, and increases in steel production may have also had a significant influence, as indicated by studies of other locations in the Changjiang drainage basin.