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Aquifer Constant Formula:
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The Aquifer Constant, also known as coefficient of transmissibility, represents the rate at which water is transmitted through a unit width of an aquifer under a unit hydraulic gradient. It is a key parameter in groundwater hydrology.
The calculator uses the formula:
Where:
Explanation: This formula calculates the aquifer constant based on discharge rate and the difference in water level drawdowns observed at two monitoring wells.
Details: Accurate calculation of aquifer constant is crucial for groundwater resource management, well field design, contaminant transport studies, and sustainable water extraction planning.
Tips: Enter discharge in cubic meters per second (m³/s) and difference in drawdowns in meters (m). Both values must be positive numbers greater than zero.
Q1: What is the significance of the constant 2.72 in the formula?
A: The constant 2.72 is derived from the natural logarithm base (e) and is part of the Theis equation derivation for unsteady-state radial flow to a well.
Q2: How does aquifer constant differ from hydraulic conductivity?
A: Aquifer constant (transmissivity) is the product of hydraulic conductivity and aquifer thickness, representing the overall transmission capacity of the entire aquifer.
Q3: What are typical values for aquifer constant?
A: Values range from 0.001 m²/s for low-permeability aquifers to over 0.1 m²/s for highly productive aquifers like gravel or fractured rock formations.
Q4: When should this calculation method be used?
A: This method is appropriate for confined aquifers where steady-state conditions can be assumed and drawdown data from at least two observation wells are available.
Q5: What are the limitations of this calculation?
A: The method assumes homogeneous, isotropic aquifer conditions, fully penetrating wells, and negligible well storage effects. Results may be less accurate in complex hydrogeological settings.