Question

What is the function of aquiclude in groundwater recharge systems?

• A. They facilitate the flow of groundwater
• B. They increase the recharge of the groundwater
• C. They act as a hindrance to ground water flow
• D. They store and transmit groundwater

Hint:

• An aquiclude is an impermeable or very low permeability geological layer.
• It can store water but does not allow significant water movement through it.
• Its primary function is to act as a barrier or hindrance to groundwater flow.
• Aquicludes form confining layers for confined aquifers and can cause perched water tables.

Answer 1

The Correct Option is C

An aquiclude is a geological formation that is saturated but relatively impermeable, meaning it can store water but does not transmit it in significant quantities. It acts as a barrier or confining layer to groundwater flow. In the context of groundwater recharge systems:

• Hindrance to Flow (option c): The primary role of an aquiclude is to prevent or greatly restrict the vertical or horizontal movement of groundwater. If an aquiclude is present above an aquifer, it can limit direct recharge from the surface. If it underlies an aquifer, it prevents downward leakage.
• Formation of Confined Aquifers: Aquicludes are essential in forming confined aquifers by sandwiching a permeable aquifer layer between two impermeable (or very low permeability) layers.
• Perching Layers: A localized aquiclude (or aquitard) within the unsaturated zone can intercept downward percolating water, leading to the formation of a perched aquifer.

Let's evaluate the options: Option (a) They facilitate the flow of groundwater: This is incorrect. Aquicludes impede flow. Aquifers facilitate flow. Option (b) They increase the recharge of the groundwater: This is generally incorrect. An aquiclude at the surface or in the unsaturated zone would typically reduce direct recharge to underlying aquifers by limiting infiltration. Option (c) They act as a hindrance to ground water flow: This is the correct function. They are barriers. Option (d) They store and transmit groundwater: They can store water (due to porosity), but they do not transmit it in significant quantities due to their very low permeability. Aquifers store and transmit. Therefore, the main function of an aquiclude in groundwater systems (including recharge considerations) is to act as a barrier or hindrance to flow. \[ \boxed{\text{They act as a hindrance to ground water flow}} \]