勐统河流域出口沉积物的^(210)Pb计年研究  

^(210)Pb dating of outlet sediments in Mengtong watershed of Yunnan

作　　者：卫仁娟[1,2] 梁川[1] Amanda H.Schmidt 张春敏[1] 

机构地区：[1]四川大学水利水电学院水力学与山区河流开发保护国家重点实验室,成都610065 [2]四川水利职业技术学院,成都611231 [3]Geology Department,Oberlin College

出　　处：《南水北调与水利科技》2015年第1期55-58,共4页South-to-North Water Transfers and Water Science & Technology

基　　金：国家重点实验室开放基金(SKLH-0F-1202);国家自然科学基金(41271045);博士点基金(20130181110045)

摘　　要：为了探索沉积速率与降水之间的相关关系,通过实验测出勐统河流域出口河漫滩沉积物剖面中210 Pb的比活度,并采用CRS(Constant Rate of 210Pb Supply)模型对沉积物进行计年,分析了20世纪50年代以来流域出口沉积物的沉积速率。210Pbex剖面分布中的两个特殊沉积点分别对应2002年和1980年,结合该流域同期的多年降水量分布情况,发现两个特殊沉积点与1970年到1980年及2002年左右的强降水密切相关。根据CRS模型计算得出流域出口的沉积速率从20世纪50年代开始一直呈现增长的趋势,这可能与流域内强烈的人类活动(森林砍伐和不合理的土地利用)有关。In order to study the relationship between the sedimentation rate and precipitation,the specific activity of 210 Pb of the floodplain sediments in the outlet of Mengtong watershed was measured by the gamma spectrometry.The age of sediments was calculated using the CRS(Constant Rate of 210 Pb Supply)model,and the sedimentation rate was analyzed since the 1950 s.Two special sediment points with high 210 Pb activity were dated at 2002 and 1980,respectively,and they had strong relationship with the precipitation from 1970 to 1980and in 2002.Sedimentation rate increased greatly from the 1950 sdetermined by the CRS model,which may be caused by the intense human activities(cutting trees and unreasonable land use)in the watershed.

关 键 词：210Pb 河漫滩沉积物 沉积速率 CRS模型 勐统河流域 

分 类 号：P597.3[天文地球—地球化学]