VS2DHI provides two interpolation methods to estimate values at cell nodes from contours that specify the initial distribution of pressure head, moisture content, and temperature.
To select an interpolation method for an initial condition, first make sure that the initial condition is selected in the "Active Data" Selector. Then
The "Continuous" Interpolation Method is suitable for initial condition distributions that vary continuously (without breaks) in the domain. This method performs a triangulation of the contour lines to generate a triangular mesh (see figure). The value at a point is computed by finding the triangle that contains the point, and then performing a linear interpolation over the triangle. If the point lies outside the triangular mesh, it is assigned the value of the nearest contour. This might or might not yield the desired result. To avoid surprises, it is recommended that either a closed contour completely encircles the domain, or that open contour lines extend sufficiently far outside the domain so that the triangular mesh completely covers the domain.
The "Step" Interpolation Method is suitable for initial condition distributions that vary in a step like manner. The step interpolation method works only with closed contours. Open contour lines are ignored. The value at a point is assinged the value of the closest contour that encloses the point. In the example figure all points in the blue region is assigned a value of 0, and all points in the red region is assigned a value of 1.
Return to: Contents