What does the term 'aquitar' refer to?

The term 'aquitar' refers to a layer of material that significantly retards or restricts the flow of groundwater. This is typically composed of materials such as clay or silt that have very low permeability. In the context of hydrology, aquitards serve as barriers to the movement of water, helping to separate aquifers or groundwater sources from surface water or other underground layers that may be more permeable.

Understanding aquitards is crucial for managing groundwater resources, as they play an important role in the hydrological cycle. While aquifers allow for the movement and storage of water, aquitards are essential for protecting these water sources from contamination and maintaining the water table.