Abstract:
Aquifer recharge is an important component of the hydrological cycle not only for the quantification of groundwater resources but also for the determination of the vulnerability of an aquifer to pollution. Daily sequential water balance method BALSEQ (developed at the National Laboratory of Civil Engineering, Lisbon, Portugal) has been used to estimate aquifer recharges and surface runoff. The method is fast, and can be used for regions with scarce hydrologic data. The model requires daily rainfall, monthly potential evapotranspiration, runoff curve number (CN) and maximum soil moisture available for evaporation as input data. The output data include daily and monthly values of surface runoff, actual evapotranspiration, aquifer recharge and soil moisture. This method was applied satisfactorily to a coastal watershed in Goa, India.