The coastal areas are transition zones where land and ocean processes interact and play a critical role. Here, several factors may trigger environmental disasters or increases hydrogeological hazard. More than half of the global population lives in the 60 km wide coastal zone and the resources for populations, such as freshwater and food, depend on the critical relationships between land and sea and their variations due to both natural and anthropogenic causes. In particular, climate changes and stresses induced by human activities, e.g. pollution, engineering interventions for dams, flood control, canalization, deforestation, urbanization, agriculture and freshwater withdrawals, cause the degradation and the ravage of the habitat. In the new millennium the management of the use of coastal areas is focussed on the integration of the monitoring systems which have to provide data and information for decision support system-based actions. In 2008 the project “An integrated monitoring and management approach of hydrologic processes in coastal ecosystems for the understanding of the relationship between continental and marine waters in the Yantai (China) and in Venice (Italy) areas” started under the umbrella of the bilateral scientific and technological agreement between the National Research Council of Italy and the Chinese Academy of Sciences. The project is carried out by the Institute of Marine Sciences of Venice and the Institute of Coastal Zone Research for Sustainable Development of Yantai. This project aims at understanding the complex relationship between continental and marine groundwater, i.e. the salt water intrusion, in two coastal areas, the Laizhou Bay (Shandong Province) in the southern Bohai Sea (China) and the Venice Lagoon (Italy). In this work we report an overview of the salt water contamination process in the two study areas and some preliminary results on a survey carried out in the Venice Lagoon, which goal was to test seismic and geoelectrical surveys for the detection of buried morphological features, such as high-permeable sandy paleo-channels, that can enhance the flow of saline water from the lagoon-sea to the inland.