Recharge
From Wikipedia, the free encyclopedia
Recharge is the process where water moves downward from surface water to groundwater. This process usually occurs in the unsaturated zone, or vadose zone.
This process is important for sustainable groundwater management, since the volume-rate abstracted from an aquifer should be less than or equal to the volume-rate that is recharged.
A recharge rate is difficult to quantify, since other related processes, such as evaporation, transpiration (or evapotranspiration) and infiltration processes must first be measured or estimated.
Recharge can be estimated using numerical methods, using such codes as HELP, UNSAT-H, SHAW, and MIKE SHE. These codes generally use climate and soil data to arrive at a recharge estimate, and use Richards equation in some form to model groundwater flow in the vadose zone.
