Mapping the impacts of the anthropogenic activities and seawater intrusion on the shallow coastal aquifer of Port Said, Egypt

Abstract

The quality and quantity of groundwater resources have been continuously deteriorating as a result of anthropogenic activities and their excessive usage. This has intensified seawater intrusion, particularly in the coastal area of Egypt. The management of this issue and preventing ongoing groundwater contamination are crucial responsibilities. Thus, an integrated strategy using remote sensing, geophysical technique, and hydrogeochemical analysis is used in this work to identify the causes of degradation and evaluate their impacts on the groundwater quality in East Port Said, Egypt. The following points were identified: 1) Remote sensing analysis between 1984 and 2015 showed an increase in anthropogenic activities, such as the construction of fish farms and vegetation, which became their areas of 12.5 and 37.8 km2 respectively. 2) Field observations demonstrated that the groundwater resources are being overexploited and it is expected that these human activities could have an impact on the groundwater quality. 3) The results of the resistivity approach indicated that sand and clay constitute the underlying layers and the shallow subsurface strata contain a high concentration of saline water. As a result, the aquifer is vulnerable to seawater intrusion due to its homogeneity. 4) Nineteen samples of groundwater were collected from the shallow Quaternary aquifer and the hydrochemical characteristic of the samples was identified. The hydrochemical analysis showed that the groundwater across the research area is of the Na-Cl water type and is highly saline (from 7,558 to 23,218 mg/L). By integrating the aforementioned techniques, it is evident that the research region is affected by anthropogenic activities as well as seawater intrusion on groundwater quality. These results serve as a solid base for further research on groundwater-surface water interactions and the evaluation of possible sources of contamination in the shallow aquifers under stress from anthropogenic activity in such environments.