Insights From a Multi-Method Recharge Estimation Comparison Study

Area of Science:

• Hydrogeology
• Water Resource Management
• Environmental Science

Background:

• Groundwater recharge estimation often uses multiple methods but struggles to differentiate method uncertainty from other influencing factors.
• Understanding groundwater recharge is crucial for sustainable shallow groundwater resource development.

Purpose of the Study:

• To investigate the added value of multi-method recharge studies for hydrogeological understanding and uncertainty characterization.
• To refine groundwater recharge estimates in a shallow aquifer in northwest Ethiopia.

Main Methods:

• Application of nine distinct groundwater recharge estimation methods (17 variations).
• Critical assessment of recharge values based on representation (actual, potential, minimum), scale, and method uncertainties.

Main Results:

• Initial recharge estimates varied widely (45–814 mm/a).
• The range for actual recharge was narrowed to approximately 280–430 mm/a.
• Significant hydrogeological insights were gained despite potential violations of method assumptions.

Conclusions:

• Multi-method recharge studies provide valuable hydrogeological insights beyond uncertainty quantification.
• Even with limited data and violated assumptions, multiple methods enhance understanding of groundwater systems.
• This approach is beneficial for assessing shallow groundwater resource development potential.