Cress Help - Ground water flow - B26.1

Darcy 

    General introduction

This calculation rule calculates the groundwater levels or hydraulic heads of some basic situations in areas with confined and unconfined aquifers and with phreatic water. The theory behind these calculation examples is also examined, by means of which complex situations can be manually calculated. Darcy’s law can also be shown and it is possible to use them to make a calculation. The WATEX and MODUFLOW computer programs can also be used to calculate groundwater flow.

    Darcy

The flow through a layer of soil (in highly permeable (filter) are) is given by:

    equation 1

in which:

• A = flow area [m2] 
• A = flow area [m2] 
• k = permeability of the soil [m/s] 
• L = length over which the difference in hydraulic head is present [m] 
• Q = flow [m3/s] 
• DH = difference in hydraulic head [m] 
• j0-j1 = difference in hydraulic head [m]