海底地下水排放（简称SGD）是陆源物质向海输送的重要通道，影响着海洋中元素的地球化学循环以及近岸海洋生态系统的平衡。本研究拟以黄河口为研究区域，利用同位素示踪、电阻率成像等技术联合示踪大型水利工程调水调沙影响下的黄河口SGD过程。通过分析调水调沙和非调水调沙等阶段黄河口镭、氡同位素的时空分布特征，探寻海域中SGD的主要排放点；借助226Ra质量平衡模型、222Rn时间序列模型、电阻率时空分布模式等手段计算SGD通量，结合降水量、黄河径流量、沿岸流场等系统剖析SGD的环境影响因素；计算各种生源要素的SGD输送通量，并与同期的黄河径流中生源要素的输送通量作比较，揭示SGD对黄河口生源要素的输送贡献。研究结果将为认识大型水利工程影响下的河口地区物质的来源归宿、收支平衡提供新的视角，为理解该海域的水体更新能力、制定合理的生态环境保护措施提供科学依据。

Submarine groundwater discharge (SGD) represents an important pathway for nutrients and other dissolved constituents from land to coastal ocean, which may significantly affect the element circulation and ecosystem balance. In this study, radioisotopes and resistance images would be used as tracers to study SGD process in the Yellow River Estuary (YRE) under the water sediment regulation event. Temporal and special distribution patterns of natural radium and radon isotopes in the YRE will be investigated to find out hot SGD points. 226Ra balance model, 222Rn time series model and resistance distribution images will be combined to calculate SGD flux. Nutrients flux transported by SGD and Yellow River will be quantified respectively and compared, in order to assess the contribution of SGD transportation. The effect of water sediment regulation to coastal SGD in the YRE will be evaluated. The information obtained here will be applied to understand the source and fate of estuarine substances from a new perspective, as well as to develop management strategies for controlling the supply of terrestrial substances to offshore areas and protect the coastal environment.