INTRODUCTION TO MODPUMP
MODPUMP is a computer program that allows calculation of aquifer parameters for a single or multiple (up to three) layer aquifer systems by simulating field pumping test data using the MODFLOW model. The program allows calculation of hydraulic conductivity, storage coefficient, specific yield and vertical leakance for up to three-layer aquifer systems. The aquifer parameters are calculated by trial and error using graphical data points matching techniques where the observed drawdown at various time periods from a field pumping test are graphically compared to MODFLOW simulated drawdown. MODPUMP has the following capabilities:
The most important aspect of this program is that it allows the user to simulate almost any field pumping test data, be it complete or partial (i.e., variable pumping rate during the test, interruptions of pumping, observation wells installed in layers other than the layer of water withdrawal, limited data points, etc.).
- Interactively input initial trial hydraulic parameters via user-friendly environment of four windows with automatically-prompted input fields.
- Specification of constant or variable pumping rates including interruptions of pumping during the pumping test.
- Execution of the MODFLOW model from within the program and generation of a graphic that compares the observed drawdown with the MODFLOW-calculated drawdown.
- For multiple-layer aquifers, the program allows specification of the layer from which the water is withdrawn during the pumping test and the layers of each observation point (up to four points are allowed). This option of vertical specification of pumping and observation wells allows a better definition of the hydraulic behavior of the aquifer system and a more accurate estimation of horizontal flow and vertical flow parameters.
- Setup of a MODFLOW-simulated pumping test within two to three minutes and calculation of aquifer parameters that are fully compatible for inclusion into a 3-D ground-water model
MODPUMP Requirements: 486/Pentium with 4 MB RAM (8 MB preferred).