Abstract:

Coastal groundwater circulation is a critical component of hydrodynamic processes and eco-environmental evolution in the land-sea interaction zone. Its dynamic evolution is driven by both natural and anthropogenic factors,exerting profound impacts on coastal resources,ecosystems,and sustainable development. This paper systematically reviews research progress on coastal groundwater circulation and its environmental effects,with a focus on the following aspects: multi-scale processes of the coastal water cycle,including surface water-groundwater interactions,tidal-driven groundwater flow dynamics,and hydrological exchange at the land-sea interface; driving factors of groundwater circulation evolution,encompassing climate change (e.g.,altered precipitation patterns,sea-level rise),human activities (e.g.,population and economic growth,land-use changes,water resource exploitation in watersheds),and geological-morphological controls on water flow; environmental effects induced by these hydrogeological processes are also examined,including nutrient and pollutant transport that influences nearshore water quality,ecological threats from seawater intrusion and soil salinization,the contribution of submarine groundwater discharge (SGD) to marine carbon/nitrogen cycles,and land subsidence hazards caused by over-extraction. The specific characteristics of these effects within China’s coastal zones are highlighted. Future research should prioritize the development of coupled multi-process models,high-resolution monitoring,management strategies that coordinate human and natural systems,and ecological impact assessments under carbon neutrality goals,thereby supporting the development of strategies for coastal water resource security and ecological conservation.

Key words: coastal zone, groundwater circulation, seawater intrusion, submarine groundwater discharge, environmental impacts, management of coastal zones