What is it?
The RMS analysis approach compares the Theis solution for a range of transmissivity values and storage coefficients against observed data and calculates the root mean sqaure (RMS) of the errors. The approximate solution for transmissivity and storage is where the RMS error is minimized.Pumptest Parameters
r (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 'r'.Q (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 'Q'.Add Observation Data
The large text field is where users can enter, copy, or load observed drawdown data needed for regression analysis. The format is: time,drawdown where time is the elapsed time since the test start, and drawdown is the change from static water level. Please use one line for each data point, with a comma seperating the drawdown from the time of observation and make sure that the units selected are consistant with the values entered.Estimation Parameters
Transmissivity Range (T_min, T_max, and NT)
The RMS analysis works by fitting data over a range of values. Enter estimates for minimum and maximum transmissivity 'T_min' and 'T_max', and the number of steps between those values 'NT'.Storage Range (S_min, S_max, and NS)
Enter estimates for minimum and maximum storage coefficients 'S_min' and 'S_max', and the number of steps between those values 'NS'.Results
Drawdown curve for best fit parameters
This plot shows the observed data and the calculated drawdown based on "best fit" storage and transmissivity after conducting RMS analysis.Contour plot of RMS error
This plot shows the RMS error contours over the transmissivity and storage coefficient ranges specified. The best fit solution sits at the minimum value (dark blue).Aquifer Properties
Transmissivity - The transmisivity value with the best fit (lowest RMS error). Transmissivity units can be changed with the dropdown to the right of the value.Storage coef. - The strorage coefficient with the best fit (lowest RMS error).