^(226)Ra and ^(228)Ra tracer study on nutrient transport in east coastal waters of Hainan Island,China

作     者：Ni SU Jin-zhou DU Tao JI, Jing ZHANG 

作者机构：State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai 200062 P. R. China 

出 版 物：《Water Science and Engineering》 (水科学与水工程（英文版）)

年 卷 期：2011年第4卷第2期

页      面：157-169页

核心收录：

学科分类：083001[工学-环境科学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学] 

基　　金：supported by the Natural Science Foundation of China (Grant No.41021064) the Sino-German Cooperation Project of Ministry of Science and Technology of China (Grant No.2007DFB20380) the Ph. D. Program Scholarship Fund of East China Normal University (Grant No.2010047) 

主　　题：Ra isotope ^226Ra and 228Ra tracers horizontal eddy diffusion coefficient nutrient flux east coastal waters of Hainan Island 

摘      要：Material fluxes （e.g., nutrients） from coastal waters to offshore areas play an important role in controlling the water quality of the adjacent sea areas not only by increasing nutrient concentration hut also by changing nutrient structures. In this study, naturally occurring isotopes, ^226Ra and ^228Ra, were measured with the alpha spectrometry in the Wenjiao-Wenchang and Wanquan estuaries and adjacent sea areas along the east coast of Hainan Island. The excess ^226Ra and ^228Ra activities were observed by comparison with the values derived from the conservative mixing of freshwater and seawater end-members in both estuaries. Using a one-dimensional diffusion model, the horizontal eddy diffusion coefficient of 3.1 6 × 10^5 cm^2/s, for nutrients diffusing from their sources, was derived from 228Ra activities. Consequently, the corresponding nutrient fluxes flowing into the coastal waters were assessed. The results can provide useful information for the study of the mixing and exchange processes of coastal waters as well as dissoluble pollutant transport in this sea area.