有关湖泊沉积^137Cs深度分布资料解译的探讨
文献类型：期刊论文
| 作者 | 张信宝
|
| 刊名 | 山地学报
 |
| 出版日期 | 2005 |
| 卷号 | 23期号:3页码:294-299 |
| 关键词 | 湖泊沉积 ^137Cs 深度分布 解译 |
| 其他题名 | Discussion on Interpretations of 137Cs Depth Distribution Profiles of Lake Deposits |
| 通讯作者 | 张信宝 |
| 合作状况 | 其它 |
| 中文摘要 | 讨论了国内有关湖泊沉积^137Cs断代资料解译的一些问题。一些高寒地区的湖泊，上世纪60年代主核爆期以后，入湖泥沙的^137Cs含量变化不大，因此沉积剖面^137Cs浓度达峰值后无明显降低趋势。一些浅水湖泊，由于人类活动扰动湖底表层泥沙，剖面表层泥沙的^137Cs浓度比较均一。根据核尘埃沉降监测资料，中国湖泊沉积应存在明显的1963年^137Cs蓄积峰，不应存在所谓的1974年^137Cs次蓄积峰，可能存在不很明显的1986年次蓄积峰。沉积剖面中^137Cs浓度的深度变化，不仅和”’CS大气沉降通量变化有关，也和流域内近几十年来的环境变化有关，1963年以后的^137Cs次蓄积峰的确定要慎重。黔中红枫湖沉积物^137Cs面积活度高于滇西湖泊，主要是由于石漠化严重的喀斯特山地，裸岩面积大，裸岩坡地几无土壤吸附^137Cs尘埃，核爆期间^137Cs降尘随降雨径流直接流失进入湖泊比例高的缘故，不是青藏高原的大气污染物散落屏蔽效应的结果。 |
| 英文摘要 | Caesium-137( 137Cs) is a man- made fallout radionuclide w ith a hal-f life of 30. 2 years that is present in the global environment , primarily as a reult of the atmospheric of nuclear w eapons in the late 1950s and early 1960s. 137Cs aerosols produced by w eapons test ing were transferred into the st ratosphere and the associated fal-l out was globally dist ributed. T he temporal pat term of annual fallout w as broadly similar across the g lobe and closely related to the intensity of weapons test ing . Significant fallout w as f irst recorded in the mid 1950s, max-i mum fallout occurred in the early 1960s , and fallout declined rapidly through the mid and late 1960s and early 1970s as a result of the nuclear test ban treaty imposed in 1963, T he expected 137 Cs depth profile, characterized by a single w el-l defined peak in 137Cs act ivity for 1963, has been documented for many lakes in China, However, non-standard 137Cs depth distribut ion prof iles w ith no single peak have been reported for several lakes in China. T hose non-standard 137 depth dist ribut ion prof iles are discussed in thid paper. In the lakes of high and cold reg ions 137 Cs is evenly dist ributed in the upper layer of deposit prof iles, because 137 Cs concent rat ions of delivering sediment into the lakes have had lit tle chang es since the nuclear weapon test ing period in the middle of 1960s. 137Cs even depth distribut ion shapes in profiles also occur in some shallow lakes , where the mud layers on the lake bot tom are often disturbed by human act ivities. According to the monitoring data on 137 Cs precipitat ion in T okyo, the 1963. s 137Cs peak should be clear and the so called/ 1974. s 137Cs peak0should not ex ist in the prof iles of some lakes. 137Cs concent rat ion changes in lake deposits are related not only to 137Cs deposition f lux fluctuations f rom the atmosphere, but also to the changes of 137Cs concentrations and act ivit ies delivering into the lake with sediments and runof fs. The higher 137 Cs inventory occurring in the Hongfeng Lake of the middle Guizhou than those in the lakes of the western Yunnan is not caued by the shelter effects of Tibet Plateau on movement and precipitaion of atmosphere aerosols. There is litt le soil ex ist to adsorb the precipitated 137Cs fallout on the bare limestone slopes, which occupies most of the Hongfeng Lake catchment, so the proportion of 137 Cs amount delivering into the lake f rom the catchment to the total precipitated 137Cs w ithin the catchment is much higher than the lakes in the western Yunnan, the catchment s of w hich are not located in limestone regions. |
| 分类号 | P512.2 |
| 资助信息 | 国家自然科学基金委员会(40271015);科技部(2003CB415202,2004CB720200);国际原子能机构(12300/RO) |
| 语种 | 中文 |
| 公开日期 | 2010-07-15 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/722]  |
| 专题 | 成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前） 成都山地灾害与环境研究所_山地表生过程与生态调控重点实验室 |
| 推荐引用方式 GB/T 7714 | 张信宝. 有关湖泊沉积^137Cs深度分布资料解译的探讨[J]. 山地学报,2005,23(3):294-299. |
| APA | 张信宝.(2005).有关湖泊沉积^137Cs深度分布资料解译的探讨.山地学报,23(3),294-299. |
| MLA | 张信宝."有关湖泊沉积^137Cs深度分布资料解译的探讨".山地学报 23.3(2005):294-299. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。