VelProbePE: An automated spreadsheet program for interpreting point velocity probe breakthrough curves

Groundwater velocity is an important parameter for determining the fate and transport of contaminants. Recently developed point velocity probes (PVPs) were designed to provide centimeter-scale measurements of the direction and magnitude of groundwater velocity based on the injection and electrical detection of a small, saline tracer. The code reported here for velocity probe parameter estimation (VelProbePE) was designed using Visual Basic for Applications (VBA) in Microsoft Excel for processing and interpreting tracer breakthrough curves specifically for PVP applications. VelProbePE contains multiple, autoinitializing user forms that guide the user through the data-processing steps. The program allows for the rapid processing and editing of up to 16 detector signals in a single workbook. VelProbePE uses simplex optimization to calculate the intermediate parameters required for the estimation of velocity magnitude and direction.