Assessment of submarine groundwater discharge in the intertidal zone of Laizhou Bay, China, using electrical resistivity tomography

Coastal zones are the most sensitive and vulnerable ecological environments in the world. Submarine groundwater discharge (SGD) is an important pathway for material transport between land and sea in the low-lying coastal plains of coastal zones. In the present study, electrical resistivity tomography was used to monitor submarine groundwater discharge in the intertidal zone. The salinity change ratio was derived using Archie's law and Manheim's equation, and was used as an index to describe the dynamic discharge process. A model of the seawater circulation process in the multilayer coastal aquifer system was established. The model contains a window area between the upper unconfined and lower confined aquifer, and a highly permeable channel in the upper silt layer. The results of the study provide a theoretical basis and technical support for the rapid assessment of SGD in low-lying coastal plains, and will assist in the management of coastal zone environments.