用镭-226示踪胶州湾的海底地下水排泄

海底地下水排泄（SGD）是全球水循环的一个组成部分，其输送的溶解物质不仅参与海洋的生物地球化学循环，而且影响近岸海域的生态环境。为了评估胶州湾海底地下水排泄状况，通过建立胶州湾内海水中²²⁶Ra的质量平衡模型来计算海底地下水排泄通量。胶州湾海水中²²⁶Ra的源主要有河流的输入、沉积物扩散输入和地下水的输入，海水系统在稳定状态下，这几种源应该与湾内海水和湾外海水的混合损失达到平衡。除了将地下水输入作为未知项外，对其他源和汇逐个进行量化，计算得知：2011年9-10月胶州湾的海底地下水排泄通量为7.85×10⁶ m³·d^-1；2012年4-5月胶州湾的海底地下水排泄通量为4.72×10⁶ m³·d^-1。在此基础上，对地下水输入胶州湾的营养盐进行了评价。

Estimating Submarine Groundwater Discharge into the Jiaozhou Bay Using 226Ra

Submarine groundwater discharge (SGD) is a part of global water cycle, which delivers a large amount of solutes to the biogeochemical cycle and affects the coastal ecological environment. The ²²⁶Ra mass balance model was established to estimate the submarine groundwater discharge to the Jiaozhou Bay. The ²²⁶Ra sources include river transport, sediment diffusion and SGD, these sources should be in balance with the mixing loss of the bay water and open seawater when the seawater system is in the stable state. Except for the SGD was unknown item, other sources and sinks were quantified one by one. Calculated results showed that the SGD fluxes during September to October in 2011 was 7.85×10⁶ m³·d^-1, April to May in 2012 was 4.72×10⁶ m³·d^-1. Based on the SGD fluxes, the SGD derived nutrient fluxes were estimated.