Using the Huisman Partial Penetration Calculators


See Also:

Huisman Method I Drawdown 

Huisman Method I Transmissivity 

Huisman Method II Drawdown 

Huisman Assumptions 


The Huisman methods provide corrections in drawdown for confined aquifers with steady-state drawdown where the observation well and pumping well do not completely penetrate the aquifer. The Huisman methods used by Infinite Extent are based on the descriptions provided by Kruseman and de Ridder (1991).


Testing and Reliability:


There have been few studies on the accuracy of the Huisman methods. Starpoint Software has performed little testing on the methods and can not guarantee that the results will predict actual field conditions. The results should be used with discretion.


Huisman I


The Huisman Method I provides a correction for drawdown in a observation well caused by the well and observation well partially penetrating the aquifer. The difference in drawdown from a fully penetrating observation well and a partially penetrating observation well is calculated with the Huisman Equation 1. To use the Huisman I method to calculate the difference in drawdown, the transmissivity of the aquifer must already be known. Because of this, this method is best used to determine how much variation in drawdown will result between a fully penetrating well and a partially penetrating well.

If the steady state drawdown is known in both the pumping well and the observation well, the Huisman Method I can be used in conjunction with the Thiem Equation to determine the transmissivity of the aquifer.


Huisman II


The Huisman Method II provides a method to determine the difference in drawdown from a fully penetrating and a partially penetrating well. The Huisman Method II is used when the steady-state drawdown in the pumping well is know, but there is no observation well. 


Kruseman and de Ridder (1991) describe the use of the Huisman Method II in conjunction with the Thiem equation to determine the transmissivity of the aquifer. However since the Thiem equation requires steady state drawdown in both the pumping well and a observation well, this technique is not practical. In situations where there is a known steady state drawdown in a observation well, Huisman Method I is more suitable.