This article discusses results interpretation in Slide groundwater analyses.
Users often ask why they have flow above the phreatic surface (i.e. Flow vectors in the unsaturated zone in Interpret).
The reason for this is that Slide performs a saturated-unsaturated steady-state seepage analysis that assumes flow above the phreatic surface. Below the water table, the degree of saturation is 100% while above the water table, the degree of saturation is less than 100%, but not 0%. Since there is water above the water table, there is still some flow. Usually the quantity of flow is small due to a reduced permeability. The permeability above the water table is defined using the permeability function defined in the groundwater properties dialog.
For more information, see the following book:
Fredlund, D.G. and Rahardjo, H. (1993). "Soil Mechanics for Unsaturated Soils." John Wiley, New York.
As described in Tutorial 14, Flow Vectors can be plotted by clicking the Flow Vectors button in Interpret.
Flow vectors displayed in Interpret for Tutorial 14
In addition, look at the Add Multiple Flow Lines option. This is also discussed in Tutorial 14.
Flow lines displayed (left half of model) in Interpret for Tutorial 14
Selecting the View>Data Tips>Query Datatips option in the Interpreter will allow you to move your cursor around the contours to see values.