delayed impact calculator
This water resource engineering tool calculates stream-aquifer system attenuation and lag for well-induced surface stream depletion or for stream-incurred return flow from deep percolation to groundwater.
Read the manual for detailed description of the finite difference formulations, solution methods, and calculation input requirements of the workbook, as well as examples of application to water use scenarios.
The finite difference formulation made available by the workbook was adapted from those published by Bittinger. No special software is necessary; native Visual Basic for Applications code operates from a tidy Excel spreadsheet interface. The numerical treatment allows discrete representation of real aquifer configurations, including flexible placement of barriers, distinct from the few configurations allowed by the analytical approaches presented by Glover and others.
Requests for assistance and suggestions for improvement are welcome.
They may be made with this contact information.