Hi all, I have a quick question see if you guys could help me:

how do you estimate groundwater recharge from precipitations? I mean in what percentage?

thanks for your attention.

Some numerical models can be used for the estimation of the groundwater recharge:
such codes as HELP, UNSAT-H, SHAW, WEAP, and MIKE SHE. The climate data like precipitation, temperature and solaridiation are used for the calculation, and use Richards equation in some form to model groundwater flow in the vadose zone(It's very important: groundwater behaves/flows differently in vedose (unsaturated) zone and saturated zone/aquifer.)


The Richards equation represents the movement of water in unsaturated soils, and was formulated by Lorenzo A. Richards in 1931 [1]. It is a non-linear partial differential equation, which is often difficult to approximate since it does not have a closed-form analytical solution.

Darcy's law was developed for saturated flow in porous media; to this Richards applied a continuity requirement suggested by Buckingham, and obtained a general partial differential equation describing water movement in unsaturated non-swelling soils.