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摘要：利用¹³⁷Cs示踪技术的前提条件是了解¹³⁷Cs的大气沉降历史,从而准确求算区域环境中¹³⁷Cs的背景值.本文利用日本秋田、东京及新泻地区¹³⁷Cs年沉降数据,并结合相应的降水数据进行修正,对辽东湾地区¹³⁷Cs的大气沉降进行了定量研究.结果表明,辽东湾地区¹³⁷Cs的大气沉降趋势与北半球基本一致;1957-2008年辽东湾地区¹³⁷Cs大气总沉降通量的模拟结果为1536 Bq·m^-2(衰变校正至2009年),与该地区土壤中¹³⁷Cs 背景值较为接近;20世纪50年代末60年代初频繁的大气核试验和1986年的切尔诺贝利核事故是1963年和1986年两个¹³⁷Cs沉降峰值产生的原因;1990年以后,沉降在地表的¹³⁷Cs在风力侵蚀作用下,发生再悬浮,使得大气中¹³⁷Cs沉降通量再次出现量级变化明显.福岛核事故产生的核素沉降对研究区的¹³⁷Cs沉降通量的影响并不明显.

Abstract：Understanding the atmospheric deposition history of ¹³⁷Cs is important in applying ¹³⁷Cs tracer technique and obtaining accurate reference inventory of ¹³⁷Cs. Based on the records of ¹³⁷Cs deposition in Akita, Tokyo and Niigata in Japan, ¹³⁷Cs atmospheric deposition in the Liaodong Bay region was investigated and quantified using the precipitation correction method. The results indicated that ¹³⁷Cs atmospheric deposition history in the Liaodong Bay was similar to that of the northern hemisphere. The cumulative atmospheric deposition inventory of ¹³⁷Cs from 1957 to 2008 was estimated to be 1536 Bq·m^-2 (decay corrected to 2009). Two significant high values of ¹³⁷Cs atmospheric deposition in 1963 and 1986 were attributed to the frequent nuclear weapon tests in 1950s~1960s and the Chernobyl nuclear accident in 1986, respectively. After 1990, ¹³⁷Cs deposited on the surface was resuspended by the wind erosion, leading to another magnitude change of the ¹³⁷Cs atmospheric deposition. The influence of the Fukushima nuclear accident to the ¹³⁷Cs atmospheric deposition of the study area was insignificant.