Hydraulic Gradient

Hydraulic gradient, abbreviated as i, a dimensionless number, is the change in height (pressure) to length between any two points.

 

Hydraulic Gradient formulas

\(\large{ i = \frac { h_1 \;-\; h_2} { l}  }\)
\(\large{ i = \frac{ Q }{ k \; A_c }   }\)
\(\large{ i =  \frac{v}{k}   }\)	(Darcy velocity)

Where:

\(\large{ i }\) = hydraulic gradient

\(\large{ A_c }\) = area cross-section of flow

\(\large{ v }\) = Darcy velocity or flux

\(\large{ Q }\) = flow rate

\(\large{ k }\) = hydraulic conductivity

\(\large{ l }\) = length of column

\(\large{ h_1 }\) = pressure head at point 1

\(\large{ h_2 }\) = pressure head at point 2

Solve for:

\(\large{ h_1 = i \;  l \;+\; h_2  }\)
\(\large{ h_2 = h_1 \;-\; i \;  l   }\)