闽江河口区水体中镭的分布特征及河水与海水的混合速率  

Distribution Characteristics of Radium and Determination of Transport Rate in the Min River Estuary Mixing Zone

作　　者：刘花台[1] 郭占荣[1] 高爱国[1] 袁晓婕[1] 李开培[1] 章斌[1] 马志勇[1] 

机构地区：[1]厦门大学环境与生态学院,福建厦门361005

出　　处：《吉林大学学报（地球科学版）》2013年第6期1966-1971,共6页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(40672166;41072174);福建省重点基金项目(2009I0025)

摘　　要：入海河口中河水与海水的混合是海洋学中一个重要的界面过程，两者混合尺度和混合速率关系到河流携带物质的扩散范围和归宿，采用天然示踪剂224Ra和^226Ra计算河水与海水的混合速率。2010年8月28日，采集了闽江河口区地下水样20个、河水样13个、河水与海水的混合水样12个，分别测量了每个水样的盐度、^224Ra活度和^226Ra活度。结果表明：地下水中^224Ra、^226Ra活度普遍高于河水；所有水体中的224Ra活度普遍都高于^226Ra活度；河水遇到海水后，^224Ra活度出现较大幅度的增加，而^225Ra活度的增加并不明显。基于^224Ra与^226Ra半衰期的差异，在只有河水与海水发生涡流混合的情况下，计算获得河水与海水的混合速率为140．2～142．5m／h。The mixing between river water and seawater is a key interface process in the estuary. The mixing scale and rate concern the dispersion range and fate of the material transported by river. The aim of this paper is to calculate the transport rate of river plume in the estuary by using naturally occurring tracer 224Ra and 226Ra. In August 2010, we collected twenty groundwater samples, thirteen river water samples and twelve mixing samples in the estuary to measure the salinity,224Ra and 226Ra activities. The results showed that, 1）224 Ra and 226 Ra activities in the groundwater samples were generally higher than those in the river water samples; 2）224 Ra activity was generally higher than 226 Ra activity in every sample; 3）224 Ra activity largely increased when river water mixed with seawater, however 226 Ra activity increased slightly. Based on the differences of radioactive half-life between 224 Ra and 226 Ra, and only eddy diffusion mixture occurring between river water and seawater, the transport rate for river plume in the estuary was calculated to be 140.2 - 142.5 m/h.

关 键 词：地下水 河水 海水 ^224Ra ^226RA 混合速率 闽江河口 

分 类 号：P641.3[天文地球—地质矿产勘探]