Recent sedimentation rates derived from 210Pb and 137Cs methods in Ise Bay, Japan
Recent sedimentation rates derived from 210Pb and 137Cs methods in Ise Bay, Japan
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DOI：
10.1016/j.ecss.2005.05.009
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发表时间：
2005-10
影响因子：
2.8
通讯作者：
Xueqiang Lu;E. Matsumoto
中科院分区：
文献类型：
--
作者：
Xueqiang Lu;E. Matsumoto
在日本伊势湾采集了10个沉积物岩心，用伽玛谱法测定了过量的210pb和137cs。采用恒通量铅-210 （CFL）模型，对伊势湾沉积速率的时空变化规律进行了研究。在上个世纪，特别是自20世纪中期以来，所有地点的沉积速率普遍呈上升趋势。20世纪中期以来沉积速率的增加与经济的快速增长和相应的环境变化的加剧是一致的。沉积速率的空间分布与时间无关。在基索河口附近发现了高沉积速率，表明河流输入是沉积物的主要来源。海湾东半部的沉积速率高于西半部，反映了悬浮物的运移路径。用210pb和137cs方法计算的近40年平均沉积速率基本一致。沉积物中过量的210pb和137cs除河口附近的一个岩心外，其余均由大气直接通量来解释。
Ten sediment cores were collected from Ise Bay, Japan, and excess210Pb and137Cs were measured gamma-spectrometrically. Using the constant flux of lead-210 (CFL) model, the temporal and spatial variations of sedimentation rates in Ise Bay were determined. A generally increasing trend in sedimentation rate over the last century, especially since the mid-20th century, was found at all of the locations. The increase in sedimentation rate since the mid-20th century is consistent with the rapid economic growth and corresponding intensification of environmental alteration. The spatial distribution of sedimentation rates is time-independent. The high sedimentation rates were found near the Kiso Rivers mouth, indicating the river input is a main source of sediment. The sedimentation rates in the eastern half of the bay are higher than those in the western half, reflecting the transport pathway of suspended matter. The mean sedimentation rates over the last 40 years derived from both210Pb and137Cs methods were roughly consistent. The inventories of excess210Pb and137Cs in sediment are accounted for by the direct atmospheric fluxes, except one core near the river mouth.