Evaluating Groundwater Recharge Potential Across Soil Textures and Vegetation Under Ponded Conditions
Nathan Strom1, T.P.A. Ferré1, Neha Gupta2
1Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ
2Arizona Institute for Resilience, University of Arizona, Tucson, AZ
As water demand rises across the United States, enhancing groundwater recharge is increasingly critical. However, predicting the ponding duration required to initiate recharge in vegetated landscapes remains challenging due to complex interactions among soil texture, vegetation properties, and antecedent soil moisture.
To quantify the conditions required to initiate recharge, a HYDRUS-1D ensemble workflow was developed to evaluate recharge feasibility, defined as the fraction of infiltrated water passing below the root zone, across diverse soil–vegetation configurations. The ensemble includes 1,325 soil textures simulated under 1–5 days of surface ponding and three vegetation types representing increasing root depth and transpiration demand. Additional simulations assess recharge sensitivity to initial soil moisture, ponding return period, and vegetation properties.
Results identify a distinct boundary separating high and low recharge feasibility across soil textures. Under short ponding durations (<1 day), recharge declines sharply near 10% clay. This boundary shifts toward higher clay contents with longer ponding durations or reduced root uptake but consistently declines near ~25% clay under maximum simulated ponding (<5 days), terminating within the loam region. Beyond this threshold, recharge is minimal except in silty clay soils, where recharge emerges when ponding exceeds three days. Recharge sensitivity to vegetation and antecedent moisture varies by texture, with soils near 50% silt exhibiting particularly nonlinear responses.
These findings support site-specific recharge evaluation and inform infrastructure design by identifying soil–vegetation conditions and ponding durations necessary to initiate groundwater recharge.