Advances in the Coastal and Submarine Groundwater Processes: Controls and Environmental Impact on the Thriassion Plain and Eleusis Gulf (Attica, Greece)

Abstract

This study focuses on the hydrogeological conditions in the coastal (Thriassion plain) and submarine (Eleusis Gulf) environment of West Attica, Greece. Up to now, the predominant aspect for the Thriassion plain groundwater—hosted within the Neogene-Quaternary sediments—was its direct hydraulic contact with the seawater. Due to that, the coastal plain groundwater is strongly believed to be of brackish quality irrespective of the local hydrodynamic conditions. Our major goal is to evaluate the actual mechanism controlling the groundwater flow, the origin and distribution of saline water, and the existence of fresh groundwater in the submarine environment. We summarize the following: (1) groundwater of the Thriassion plain is partly discharged as an upwards leakage from deeper aquifers, (2) modern direct seawater intrusion is not possible in the Neogene-Quaternary sediments, and (3) fresh groundwater possibly exists below the sea floor of the Eleusis Gulf. The results may serve as hint of further research in groundwater resources below the Mediterranean Sea floor, and, consequently, a new perspective on water resource management could emerge.

Natural Processes and Anthropogenic Activity in the Indus River Sedimentary Environment in Pakistan: A Critical Review

“…In the absence of human intervention, water quality changes are caused by natural processes such as bedrock evapotranspiration and wind-deposited dust [138]. Water's physical and chemical composition may vary due to natural processes including soil erosion and runoff, as well as hydrological variables that cause runoff and biological activities in aquatic environments [139][140][141][142]. The Indus River's natural environment may include both dissolved and undissolved elements as a result of natural processes [125], thus this information should be taken into consideration.…”

The Environmental Impact of a Complex Hydrogeological System on Hydrocarbon-Pollutants’ Natural Attenuation: The Case of the Coastal Aquifers in Eleusis, West Attica, Greece

“…The latter is comprised of limestones, dolomitic limestones and dolomites. The Cretaceous and Triassic aquifers flow to the southwest and discharge partly through coastal springs near the city of Eleusis and the entire North-Western coastline of the Eleusis Gulf and partly into Neogene-Quaternary deposits [39,40]. From this field work, the seasonal water level fluctuations in the unconfined aquifer were measured 0.4-0.5 m and within the confined aquifers 1.2-1.5 m. A conceptual model of the deposits in Figure 3 illustrates the multi-level aquifer conditions within the Pleistocene strata, where lenticular intercalation consists of a water-yielding formation [31].…”

The Effect of Urban Land-Use Change on Runoff Water Quality: A Case Study in Hangzhou City

“…In addition, some researchers point out that other factors relating to urban land can affect water quality, such as erosive rainfall events, heavy metals in surface sediments, natural biological filtration devices, and the landscape pattern of the surrounding zones in the urban area. These water quality studies have identified key variables that affect the physical, chemical, and biological processes of surface water bodies [27][28][29][30][31][32].…”