The Strong Impact of Precipitation Intensity on Groundwater Recharge and Terrestrial Water Storage Change in Arizona, a Typical Dryland

Abstract

Abstract This study demonstrates the critical role of precipitation intensity in groundwater recharge generation and terrestrial water storage (TWS) change. We conducted two experiments driven by precipitation products with close annual totals but distinct intensity in Arizona, using the Noah‐MP model with advanced soil hydrology. The experiment with higher precipitation intensity (EXPHI) produces an annual groundwater recharge of 6.91 mm/year in Arizona during 2001–2020, ∼15 times that of the experiment with lower precipitation intensity (EXPLI). Correspondingly, EXPLI produces a declining groundwater storage (GWS) trend of −0.51 mm/month, nearly triple that of EXPHI. GWS change dominates the TWS trend. EXPLI shows a declining TWS trend of −0.57 mm/month, nearly twice that of EXPHI. Higher precipitation intensity reduces evapotranspiration and enhances infiltration and percolation, allowing more precipitation to recharge groundwater. This study underscores the need to ensure the accuracy of precipitation intensity in hydrological modeling for reliable water resources assessment and projection.

Keywords

• precipitation intensity
• groundwater recharge
• groundwater storage
• terrestrial water storage
• evapotranspiration
• Noah‐MP