地理研究 ›› 2015, Vol. 34 ›› Issue (4): 655-665.doi: 10.11821/dlyj201504005

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北部湾防城港沿岸土壤137Cs背景值及表层分布特征

徐伟1(), 潘少明1(), 贾培宏1, 杨旭1, 曹立国1, 张威1, 阮向东2, 管永精2   

  1. 1. 南京大学地理与海洋科学学院, 南京 210023
    2. 广西大学物理科学与工程技术学院, 南宁 530004
  • 收稿日期:2014-11-21 修回日期:2015-01-05 出版日期:2015-04-10 发布日期:2015-04-10
  • 作者简介:

    作者简介:徐伟(1989- ),男,安徽六安人,硕士,主要从事放射性核素的应用研究。E-mail: xuwei_ne@163.com

  • 基金资助:
    国家自然科学基金项目(41166002, 41271289);国家自然科学基金重点项目(41230751)

137Cs reference inventory and its distribution in surface soil along the Fangchenggang coastal zone of Beibu Gulf

Wei XU1(), Shaoming PAN1(), Peihong JIA1, Xu YANG1, Liguo CAO1, Wei ZHANG1, Xiangdong RUAN2, Yongjing GUAN2   

  1. 1. School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
    2. Physics Science and Engineering Technology Department, Guangxi University, Nanning 530004, China
  • Received:2014-11-21 Revised:2015-01-05 Online:2015-04-10 Published:2015-04-10

摘要:

在北部湾防城港沿岸采集土壤样品,通过测量样品137Cs比活度及有机质含量,确定了137Cs背景值,分析表层土壤中137Cs分布特征,并探讨样品中137Cs活度与有机质含量的关系。结果表明:研究区土壤中137Cs背景值为626±15 Bq/m2,自然因素和人为活动对137Cs在海岸带表层土壤中的再分配起到重要作用,不同表层样中137Cs比活度高低表现为:自然林地>水稻田>旱田>草地>河口海湾。把研究区土壤表层样及P01剖面样中137Cs含量与有机质含量进行相关性分析,结果表明:两者相关性显著,相关系数分别为0.414和0.732。通过探讨研究区137Cs背景值及沿岸表层土壤137Cs分布特征,可为进一步定量研究北部湾沿岸土壤侵蚀和堆积状况以及评价防城港红沙核电站运行后对环境的影响提供科学依据。

关键词: 137Cs背景值, 表层土壤137Cs分布, 有机质含量, 大气沉降, 北部湾, 防城港

Abstract:

The background values of 137Cs along the coast of the Beibu Gulf have not been sufficiently presented in China so far. This thesis collected 55 surface samples and 1 profile sample in the Beibu Gulf. The specific activity of 137Cs and organic contents of individual sample were tested and the accumulation amount of 137Cs in the section sample was calculated. The background value of 137Cs in the research area was finally determined. The thesis also analyzed the distribution features of 137Cs in surface soil along the Fangchenggang coastal zone of the Beibu Gulf. The relationship between the specific activity of 137Cs and organic contents in the sample soil was discussed as well. The findings showed that the background value of 137Cs in the soil of the research area was 626±15 Bq/m2, and the atmospheric precipitation of 137Cs accorded with the precipitation condition of 137Cs in the northern hemisphere. By comparing the background values of 137Cs in multiple places within China, it is suggested that the variance among the background values of 137Cs in regions at the same latitude can mainly be attributed to rainfall. Moreover, the spacial distribution variance of latitude zone, climate factors like typhoon and the particularity of geographic position also have great potential to influence the precipitation of 137Cs. The research on the specific activity of the surface samples and the distribution of sampling sites suggested that natural factors and human activities played an important role in the redistribution of 137Cs in soil. The specific activity of 137Cs in different surface samples exhibited the following order from high to low: natural forest land, paddy field, dry land, grassland, and estuary and gulf. A Pearson’s correlation analysis was conducted and significant corelation was found between the values of 137Cs content and organic contents in the surface samples and P01 sediment core, with the corelation coefficients being respectively 0.414 and 0.732. Discussing the background value of 137Cs in the Fangchenggang coastal zone of the Beibu Gulf and the distribution features of 137Cs in surface soil along the coast can promote further quantitative research on soil erosion and accumulation along the coast of the Beibu Gulf as well as provide scientific evidence for the evaluation of the environmental impact of the Red Sand Plant.

Key words: 137Cs reference inventory, 137Cs distribution in surface soil, organic content, atmospheric precipitation, Beibu Gulf, Fangchenggang