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PrefaceThis report documents several spreadsheets that have been developed for the analysis of aquifer-test and slug-test data. Each spreadsheet incorporates analytical solution(s) of the partial differential equation for ground-water flow to a well for a specific type of condition or aquifer. The spreadsheets were written in Microsoft Excel version 9.0. Use of trade names does not constitute endorsement by the U.S. Geological Survey (USGS). The spreadsheets have been tested for accuracy using datasets from different aquifer tests or generated from the analytical solution. If users find or suspect errors with these spreadsheets, please contact the USGS.Every effort has been made by the USGS or the United States Government to ensure the spreadsheets are error free. Despite our best efforts, the possibility exists that there are errors in the spreadsheets. The distribution of the spreadsheets does not constitute any warranty by the USGS, and no responsibility is assumed by the USGS in connection therewith.

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[1] A conduit flow process (CFP) for the Modular Finite Difference Ground-Water Flow model, MODFLOW-2005, has been created by the U.S. Geological Survey. An application of the CFP on a carbonate aquifer in southern Florida is described; this application examines (1) the potential for turbulent groundwater flow and (2) the effects of turbulent flow on hydraulic heads and parameter sensitivities. Turbulent flow components were spatially extensive in preferential groundwater flow layers, with horizontal hydraulic conductivities of about 5,000,000 m d À1 , mean void diameters equal to about 3.5 cm, groundwater temperature equal to about 25°C, and critical Reynolds numbers less than or equal to 400. Turbulence either increased or decreased simulated heads from their laminar elevations. Specifically, head differences from laminar elevations ranged from about À18 to +27 cm and were explained by the magnitude of net flow to the finite difference model cell. Turbulence also affected the sensitivities of model parameters. Specifically, the composite-scaled sensitivities of horizontal hydraulic conductivities decreased by as much as 70% when turbulence was essentially removed. These hydraulic head and sensitivity differences due to turbulent groundwater flow highlight potential errors in models based on the equivalent porous media assumption, which assumes laminar flow in uniformly distributed void spaces.