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Saltwater Intrusion

Understanding saltwater intrusion

Saltwater intrusion occurs when seawater infiltrates freshwater aquifers or coastal groundwater systems, often leading to degraded water quality. Key causes include:
  • Over-extraction of groundwater: Excessive pumping reduces pressure in freshwater aquifers, allowing saltwater to move in.
  • Rising sea levels: Climate change raises sea levels, pushing saltwater further inland.
  • Natural changes: Tidal or seasonal shifts disrupt the balance between freshwater and saltwater.
Addressing saltwater intrusion requires precise mapping and monitoring of the affected zones. Advanced geophysical tools, such as tTEM and floaTEM, provide detailed subsurface imaging to:
  • Identify the interface between freshwater and saltwater.
  • Monitor the extent of saltwater intrusion over time.
  • Support groundwater management strategies to mitigate its effects.
By leveraging tools like tTEM and floaTEM, stakeholders can better manage coastal groundwater systems and develop effective solutions to combat saltwater intrusion.

TEM's role in supporting saltwater intrusion

Shallow Mapping

tTEM is perfect for mapping areas where saltwater is creeping into freshwater aquifers. By detecting resistivity differences, it can pinpoint where saltwater and freshwater meet, helping us understand the extent of saltwater intrusion.

Rapid Large-Area Coverage

The towed design of tTEM lets us quickly survey large coastal areas, including beaches and aquifers near the coast. This makes it ideal for mapping extensive areas at risk of saltwater intrusion.

Groundwater Surface Interaction

tTEM can help assess where groundwater and surface water, like rivers or estuaries, are vulnerable to saltwater contamination. This helps identify the areas most at risk and their impact on local freshwater sources.

Tracking Changes Over Time

With repeated surveys, tTEM can help us monitor how saltwater intrusion progresses, which is key for understanding the effects of climate change, sea-level rise, and human activities like excessive groundwater pumping.

Deep Insights

sTEM excels at providing deep penetration into the ground, helping us map saltwater intrusion deeper into freshwater aquifers—something that’s challenging with other methods.

High Resolution Data

sTEM can deliver detailed measurements at specific locations like wells, riverbanks, or coastal areas. It provides accurate resistivity data that helps differentiate between freshwater, brackish, and saltwater zones at various depths.

Mapping Subsurface Layers

sTEM helps us visualize the boundary between saltwater and freshwater in deeper parts of aquifers, which is crucial for understanding how saltwater moves underground. This is essential for creating strategies to prevent further intrusion.

Help monitor, assess, and mitigate saltwater intrusion