Surface data consists of an ordered array of interpolated values at regularly spaced intervals that represent the spatial distribution of an attribute, e.g., digital elevation models. Surface data can be used in Visual MODFLOW Flex in the following ways:
•To define the horizons (structural zone vertical boundaries) of a conceptual model.
•To define the spatial distribution of a boundary condition attribute.
•To define the spatial distribution of a property zone attribute, e.g., conductivity, initial heads.
•To visualize the spatial variation of model features, e.g., surface topography, water table elevation, etc.
Visual MODFLOW Flex supports the following surface file types:
•ESRI ASCII Grid (*.ASC, *.TXT)
•Surfer Grid (*.GRD)
•USGS Digital Elevation Model (*.DEM)
To import surface data, follow the steps below:
•Right-click in the Data Explorer and select Import Data... from the pop-up menu.
•Select Surface from the Data Type drop down list box.
•Click the [...] button and locate the source file.
•Enter a Name and a Description for the imported data, and click [Next] to continue.
Note: Surface files that contain a large quantity of data points may require substantial time to import into Visual MODFLOW Flex.
Next, select the Coordinate System of the data being imported. If the coordinate system is different than the one defined in the project settings, Visual MODFLOW Flex will perform a geotransformation, converting all coordinates to the project’s coordinate system. Click the [Next] button to continue to the next step
Surface data will usually only consist of three columns: X, Y and Attribute Data (elevation, conductivity, etc). Visual MODFLOW Flex will automatically map the source columns to the target fields. You can preview the mapped data before importing into Visual MODFLOW Flex.
Click the [Next] button to finish the import process. Upon importing, a new data object will be added to the Data Explorer.