Jacob-Cooper Approximation for Theis Equation
The equation for predicting drawdown under these conditions is:
Pumptest Parameters
Enter these parameters (or use defaults) before clicking "Estimate Parameters" to run the Jacob-Cooper analysis.Distance from well
This represents the radial distance from the well to the point of drawdown observation. Use the default value or assign a different value for distance in the text field next to 'Distance from well'.Pumping Rate
A steady (time-independent) pumping rate input is needed for this analysis. Use the default value or assign a different value for the pumping rate in the text field next to 'Pumping Rate'.Start Time
This is a time offset for the observed data. Observation data is shifted by this ammount before calculating result. Enter the start time as a number and choose the correct units.Add Observation Data
The large text field is where users can enter, copy, or upload observed drawdown data needed for regression analysis. The format is: time, drawdown. Please use one line for each data point, with a comma seperating the drawdown from the time of observation. Make sure the the "Time Units" and "Value Units" dropdowns match those entered.Results
After clicking "Estimate Parameters" the following results will be calculated.Best Fit Stats
R2 indicates how well the Jacob-Cooper analysis fits the data (0-1). A low value (0) indicates poor fit, and a high value (1) indicates good fit.Slope,m of the best fit line is used to estimate aquifer transmissivity and storage.
y-intercept, s0 of the best fit line is used to estimate the aquifer storage coefficient.
t0/r02 is the relationship between x and y intercepts of the best fit line, and is used to derive aquifer storage estimates.
Aquifer Properties
T is the estimate for aquifer transmissivity. The user can use the units dropdown to view transmissivity results in different units.S is the estimate for the aquifer storage coefficient.