辽东湾沿岸土壤中^137Cs背景值及分布特征研究

^(137)Cs Reference Inventory and Its Distribution in Soils along the Liaodong Bay

在辽东湾沿岸区域采集了20个土壤表层样和7个非耕作土壤剖面样(其中一个为标准剖面),通过对采集的土壤样品中的137 Cs进行测量与分析,确定该区域土壤中137 Cs的背景值,并探讨了土壤中137 Cs的分布特征。结果表明,研究区137 Cs的背景值为(1 704±40)Bq/m2;表层土壤中137 Cs的比活度范围为0.84～19.90Bq/kg,不同土地利用类型表层土壤中的137 Cs比活度有明显差异,比活度高低依次为:草地>盐碱地>耕地;非耕作土壤剖面中137 Cs的总量范围为65～1 535Bq/m2,大部分土壤剖面中137 Cs呈指数递减分布,且剖面中的137 Cs发生不同程度的流失,而受到沉积扰动作用的剖面中137 Cs分布无规律。通过探讨辽东湾沿岸区域土壤中137 Cs的背景值及137 Cs的分布特征,为利用137 Cs示踪技术定量研究该区域物质输移和辽东湾沉积物来源提供依据。

Levels of 137Cs from weapons fallout on soils along the Liaodong Bay were presented.The activity of 137Cs was measured at 20 surface soils different in land use（grass land,cultivated land and saline land） and 7 non-cultivated soil profiles（one as the reference profile）.The 137Cs reference inventory in the study area was determined to be（1 704±40） Bq/m2.The specific activity of 137Cs in surface soils ranged from 0.84 Bq/kg to 19.90 Bq/kg,following an order of grass land saline land cultivated land.The inventory of 137Cs in 6 profiles ranged from 65 Bq/m2 to 1 535 Bq/m2.137Cs depth distribution in most of soil profiles was in the form of exponential decay and 137Cs loss was in different degrees.In the soil profile affected by sedimentation and disturbance,137Cs depth distribution was in the form of disorder.Studying on 137Cs reference inventory and its distribution in soils along the Liaodong Bay could support the quantitative analysis on the material transportation in this area and the source of sediments in the Liaodong Bay by 137Cs tracing technique.