Evaluation and Documentation of the ST. Johns River Water Management District Three-Layer Analytical Groundwater for Use by Permit Applicants.

摘要

The investigation described in this draft report consisted of four tasks: Review and enhancement of the two-layer model; Development of source code and documentation for the three-layer model; Preparation of a draft final project report (user’s manual); and Preparation of a final report (user’s manual). In the first task, the District’s existing two-layer model (Motz and Acar 2007, based on Denis and Motz 1998) was reviewed, along with existing analytical solutions for pumping from multiple aquifers (e.g., Cheng 2000, Hemker 1984 and 1985, and Hunt 1985). Suitable solutions (i.e., Hemker 1984 and 1985 and Hemker and Maas 1987) were selected for application to three three-layer hydro-geologic conditions in northeast Florida. In the second task, software was created to calculate drawdowns due to pumping from a three-layer aquifer system. The software consists of two programs, i.e., 3LAYSS can be used to calculate steady-state drawdowns due to pumping from single or multiple wells, and 3LAYT can be used to calculate transient draw-downs due to pumping from single or multiple wells. In this task, FORTRAN source codes were written for the three-layer steady-state and transient draw-down solutions selected in the first task. Beta versions of the three-layer steady-state and transient codes were provided to the District for testing purposes. Also, beta versions of the three-layer draw-down models underwent benchmark testing by the University using selected analytical and numerical problems. Based on the benchmark testing by the University and review of the beta versions by the District, final versions of the steady-state and transient three-layer draw-down models were developed. In the third task, this draft final project report (user’s manual) has been prepared. Based on the first two tasks, this report includes a description of the problem, three-layer steady-state.