Darcy’s Law:
In 1856, Darcy published a simple equation for the discharge velocity of water through saturated soil,which may be expressed as..
v=ki
where,
v=discharge velocity,which is the quantity of water in unit time through a unit gross cross-sectional area of soil at right angles to the direction of flow.
k=hydraulic conductivity( also known as co-efficient of permeability)
The equation was based primarily on Darcy’s observations about the flow of water through clean sands