Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.scitotenv.2023.162857
Document author version
Title (Primary) Dynamics of upstream saltwater intrusion driven by tidal river in coastal aquifers
Author Zhang, B.; Zheng, T.; Zheng, X.; Jiang, S.; Cao, M.; Walther, M.; Lu, C.
Source Titel Science of the Total Environment
Year 2023
Department ENVINF
Volume 877
Page From art. 162857
Language englisch
Topic T5 Future Landscapes
Keywords Tidal river; Coastal aquifer; Saltwater intrusion; Water exchange; Numerical models
Abstract For the coastal aquifers, recent research have shown that the tidal has a significant effect on saltwater intrusion in the near-shore aquifer. However, it is currently unclear how the tidal river contributes to the groundwater flow and salinity distribution in the upstream aquifer of the estuary. This study examined the effects of a tidal river on the dynamic characteristics of groundwater flow and salt transport in a tidal river-coastal aquifer system using field monitoring data and numerical simulations. It was found that changes in tidal-river level led to the reversal of groundwater flow. For a tidal cycle, the maximum area of seawater intrusion is about 41.16 km2 at the end of the high tide stage. Then the area gradually decreased to 39.02 km2 at the end of the low tide stage. More than 2 km2 area variation can be observed in a tidal cycle. Compared to the low tide stage, the area of SWI increased by 5 % at high tide stage. The SWI region was also spreading landward from the tidal river. In addition, we quantified the water exchange and salt flux between the tidal river and aquifer. When the tidal fell below the level of the riverbed, the water exchange rate was stabilized at about −1.6 m/h. The negative value indicated that the river was recharged by the groundwater. With the increasing of tidal water level, the water exchange rate gradually changes from negative to positive and reached the maximum value of 3.2 m/h at the beginning of the falling tide stage. The presence of a physical river dam can amplify the difference in water level between high and low tides, thereby enhancing the influence of a tidal river on water exchange and salt flux. The findings lay the foundation for gaining a comprehensive understanding of the tidal river on groundwater flow and salt transport in upstream aquifers.
Persistent UFZ Identifier
Zhang, B., Zheng, T., Zheng, X., Jiang, S., Cao, M., Walther, M., Lu, C. (2023):
Dynamics of upstream saltwater intrusion driven by tidal river in coastal aquifers
Sci. Total Environ. 877 , art. 162857 10.1016/j.scitotenv.2023.162857