地理学报 ›› 2011, Vol. 66 ›› Issue (11): 1551-1561.doi: 10.11821/xb201111011

• 水文地貌与第四纪 • 上一篇    下一篇

云南抚仙湖近现代沉积速率变化研究

王小雷1,2, 杨浩1, 丁兆运1,3, 杨本俊1,4, 张明礼1   

  1. 1. 南京师范大学地理科学学院, 南京 210046;
    2. 南京晓庄学院生物化工与环境工程学院, 南京 211171;
    3. 枣庄学院旅游与资源环境学院, 山东枣庄 277160;
    4. 皖西学院资源环境与旅游管理学院, 安徽六安 237012
  • 收稿日期:2011-07-05 修回日期:2011-08-22 出版日期:2011-11-20 发布日期:2011-11-20
  • 通讯作者: 杨浩(1960-), 男, 教授, 博士生导师, 主要从事土壤侵蚀与环境影响等研究。E-mail: yanghao@njnu.edu.cn
  • 作者简介:王小雷(1982-), 男, 博士, 讲师, 主要从事湖泊沉积与环境演化研究。E-mail: xlwang0718@163.com
  • 基金资助:

    国家自然科学基金项目(40873071; 41030751); 江苏省高校自然科学研究项目(09KJA170002); 南京师范大学优秀博士学位论文培育基金项目(1243211601039)

Modern Sedimentation Rates of Fuxian Lake by 210Pb and 137Cs Dating

WANG Xiaolei1,2, YANG Hao1, DING Zhaoyun1,3, YANG Benjun1,4, ZHANG Mingli1   

  1. 1. School of Geography Science, Nanjing Normal University, Nanjing 210046, China;
    2. Collegel of Biochemical and Environmental Engineering, Nanjing Xiaozhuang University, Nanjing 211171, China;
    3. College of Tourism, Resources and Environment, Zaozhuang University, Zaozhuang 277160, Shandong, China;
    4. College of Resource Environment and Tourist Management, Western Anhui University, Lu'an 237012, Anhui, China
  • Received:2011-07-05 Revised:2011-08-22 Online:2011-11-20 Published:2011-11-20
  • Supported by:

    National Natural Science Foundation ofChina, No.40873071; No. 41030751; National Science Foundation of the Jiangsu Higher Education Institutions ofChina, No.09KJA170002; Scientific Research Foundation of Outstanding Doctoral of Nanjing Normal University,No.1243211601039

摘要: 借助GPS定位,采集了云南抚仙湖不同区域的7 个沉积物柱芯。通过对抚仙湖沉积物柱芯样品的放射性核素210Pb 和137Cs 测试分析,发现所有柱芯中均存在3 个公认的137Cs 计年时标(1954 年137Cs首次沉降、1963 年全球公认的137Cs最大沉降蓄积峰和1986 年前苏联切尔诺贝利核事故产生的137Cs 沉降蓄积峰),部分柱芯中存在20 世纪70 年代中期中国大气核试验形成的1975/1976 年次级蓄积峰,分析了该次级定年时标存在的合理性。借助210Pb CRS计年模式获得了抚仙湖过去百余年来的沉积年代,与137Cs 时标计年结果相比较存在一定偏差,对两种计年结果产生差异的可能原因进行了探讨。基于210Pb 和137Cs 计年结果,结合历史文献记载得出,自19 世纪中期以来,抚仙湖各个沉积物柱芯(FX6 除外) 的沉积速率变化规律具有相似性,大致可以划分为3 个阶段:A:自然演化阶段,B:人为扰动阶段,C:人为改造阶段。这种不稳定的沉积环境与抚仙湖地区相应历史时期的人类活动有密切关系,表明人类活动是影响短时间尺度下环境变化的主要驱动力。

关键词: 210Pb计年, 137Cs计年, 抚仙湖, 沉积速率, 人类活动

Abstract: Based on GPS location, seven sediment cores were collected from different areas of Fuxian Lake. By analyzing the radionuclide profiles of 210Pb and 137Cs, we found that there were three obvious time markers of 137Cs in all the sediment cores, which corresponded to the onset of fallout in 1954, the maximum peak fallout in 1963 and the former Soviet Union's Chernobyl accident in 1986. Some sediment cores (FX1, FX3, FX5 and FX7) had the secondary peaks in 1975 or 1976 by the Chinese nuclear tests, verifying the rationality of this auxiliary time marker. On the basis of the 210Pb (CRS) dating, the ages were obtained in the past 150 years. As for dissimilar physical and chemical associations, diffusion characteristics for the two radionuclides (Pb and Cs), we interpreted the rationality of deviation by the two dating methods. In combination of the 210Pb and 137Cs dating results and historical data, we found that the modern sedimentation rates in different sediment cores (except FX6) of Fuxian Lake had a similar tendency, which can be marked off three stages: natural evolution stage, man-made disturbances stage and man-made transformation stage. In the short time-scale, human activities of historical periods had played a very important role in changing the sedimentation environment of the Fuxian Lake.

Key words: 210Pb dating, 137Cs dating, Fuxian Lake, sedimentation rate, human activities