Comparison of Selected Methods for Estimating Groundwater Recharge In Humid Regions

Method:	Category:	Spatial Scale:	Temporal Scale:	Quantity Estimated:	Ease of Use:	Data Needs:	Cost:
Groundwater Modeling	Groundwater	Local to Regional	Month to Years	Recharge	Moderate	High	High
Ground-water models such as MODFLOW can be used to estimate groundwater recharge by calibration of the model to "known" values of aquifer transmissivity, hydraulic head, and discharge (base flow). Recharge for various temporal and spatial scales can be estimated; however, the accuracy of the estimates are dependent upon the quality of the data for transmissivity, head, and discharge. If discharge data are not available, recharge estimates will be non-unique. Use of groundwater models requires modeling software and considerable expertise. Costs are moderate to high. Numerous groundwater model codes are available.