¹⁸O and ²²⁶Ra in the Minjiang River estuary, China and their hydrological implications

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• 作者：Huatai Liu^a ; ^{lht@xmu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Zhanrong Guo^b ; Aiguo Gao^b ; Xiaojie Yuan^b ; Bin Zhang^b
• 关键词：18O ; 226Ra ; Mixing ratio ; Groundwater discharge ; Minjiang River estuary
• 刊名：Estuarine, Coastal and Shelf Science
• 出版年：2016
• 出版时间：5 May 2016
• 年：2016
• 卷：173
• 期：Complete
• 页码：93-101
• 全文大小：898 K

文摘

In this work, the ²H, ¹⁸O and ²²⁶Ra values in groundwater and surface water in the Minjiang River estuary were investigated in the dry and wet seasons. The δ¹⁸O values in the dry season were always higher than those in the wet season in both groundwater and surface water because of the presence of evaporation in the water cycle process. During the dry season, the δ¹⁸O values in groundwater on the southern bank of the Minjiang River are much higher than those on the northern bank because evaporation is more intense in the farmland of the southern bank than in the urbanized northern bank. The δ¹⁸O values in the estuarine water exhibit a good positive correlation with salinity, with a coefficient of 0.96 (p = 0.05) in both seasons. The ²²⁶Ra activities in the estuarine water increase with increasing salinity because of desorption from riverine suspended particles. The ²²⁶Ra activity reaches a peak value at a salinity of 20.5. Based on a three-endmember model, the average proportions of the estuarine water are calculated to be 0.02 for groundwater, 0.39 for river water and 0.59 for seawater. From this mixing ratio, the groundwater discharge into the estuary is estimated to be 9.31 × 10⁶ m³ d⁻¹ in the wet season.