How does saltwater intrusion impact freshwater aquifers?

Saltwater intrusion has significant consequences for freshwater aquifers, primarily leading to the loss of freshwater resources. This phenomenon occurs when saltwater from oceans or estuaries encroaches into freshwater aquifers, often as a result of over-extraction of groundwater or rising sea levels. When saltwater replaces freshwater in these aquifers, it can render the water unsuitable for drinking and irrigation purposes, which impacts agricultural productivity and drinking water availability.

The intrusion alters the chemical composition of the water within the aquifer, increasing salinity levels to the point where the water is no longer safe for human consumption or agricultural use. This can lead to challenges in managing water supply and necessitate the implementation of costly desalinization processes or other remedial measures.

In contrast, the other options do not accurately reflect the implications of saltwater intrusion. While one might consider that increased groundwater levels could be a potential effect, the reality is that the intrusion lowers the quality of the groundwater available, not necessarily its volume. It is also incorrect to suggest that saltwater intrusion enhances water quality or has no effect on aquifers, as the primary concern surrounding this issue is the degradation of freshwater resources.