Various methods are available for estimation of the groundwater recharge. Some of the frequently used methods for estimation of groundwater recharge are,

• •  Groundwater balance method

•  Empirical formula

•  Groundwater table fluctuation method

•  Zero flux plane method

•  Darcy's law

•  Tracer techniques

 

Groundwater balance method

Groundwater balance method can be used for quantitative estimation of groundwater recharge. The groundwater balance equation described earlier can be used to estimate the aquifer recharge. The equation can be written as,

Inflow to the system – Outflow from the system = Change in the storage of the system over a period of time

Putting the various inflow and outflow components, the above equation can be written as,

Where, R_r is the recharge from rainfall, R_c is the recharge from canal seepage, R_i is the recharge from field irrigation, l_s is the influent seepage from river, l_b is the inflow from other basin, E_t is the evapotranspiration, P is the withdrawal from the aquifer, O_s is the effluent discharge to the river, O_b is the outflow to other basin and is the change is storage. Knowing the other components of the groundwater balance equation, the groundwater recharge can be estimated.