东中国海表层海水137Cs分布的影响因素

采集山东半岛附近海域表层海水样品，分析137Cs分布特征，并结合东中国海137Cs比活度数据，探讨影响表层海水137Cs分布的因素。结果表明:（1）山东半岛附近海域表层海水137Cs比活度在0.60±0.18~1.21±0.19 Bq/m3之间，平均值为0.90±0.17 Bq/m3。沿岸137Cs比活度较离岸小，主要受沿岸流影响。（2）东中国海各海域137Cs空间分布受大气不均匀沉降，沿岸流，河流冲淡水等因素影响；随时间变化，整个东中国海表层137Cs活度降低，切尔诺贝利核事故对东中国海影响不大。（3）渤海表层137Cs海水析出速率为0.046/a，高于黄海（0.032/a）和东海（0.027/a），与较高的颗粒物质吸附能力和水体横纵向混合过程有关。

Influence factors of 137Cs distribution in surface seawater of East China Seas

By collecting surface seawater near Shandong Peninsula, then analyze the surface distribution of 137Cs, the data is combined with the East China Seas to explore the factors affecting the distribution of 137Cs. The conclusions are as follows:(1) 137Cs activity in study area ranges from 0.60±0.18 Bq/m3 to 1.21±0.19 Bq/m3, with an average of 0.90±0.17 Bq/m3. And 137Cs activity of near shore is lower than offshore, mainly effected by coastal current; (2) The spatial distribution of 137Cs in East China Seas are influenced by uneven distribution of the atmospheric deposition, coastal flow, river dulite water in seawater. The value of 137Cs decreased sequentially and the Chernobyl accident has less impact on East China Seas; (3) The removal rate of 137Cs in Bohai Sea is 0.046/a, which is higher than the Yellow Sea (0.032/a) or East China Sea (0.027/a), because of more scavenging and stronger horizontal and vertical mixing of water masses.