Definition
The intrinsic fluid property indicating the internal resistance to flow.
Description
Viscosity is a measure of how a liquid is resistant to flow; "thickness" or "thinness". Methanol has a low viscosity, while vegetable oil has a high viscosity. Viscosity generally decreases as temperature increases.
Why is viscosity important?
Plays a role in the movement of NAPL contaminants through the subsurface.
Source: http://www.indium.com