A high-resolution map of diffuse groundwater recharge rates for Australia

• DOI: 10.5194/egusphere-2023-2414
• Publication Date: 2023-10-26T05:25:09Z
• Authors: Stephen Lee; Dylan J. Irvine; Clément Duvert; Gabriel C. Rau; Ian Cartwright
• Keywords: Depression-focused recharge

Abstract. Estimating groundwater recharge rates is important to understand and manage groundwater. Numerous studies have used collated datasets project regional or global-scale rates. Recharge estimation methods each distinct assumptions, quantify different components, operate over temporal scales. To address these challenges, we use 200,000 chloride measurements estimate using the mass balance (CMB) method across Australia. were produced stochastically gridded deposition, runoff, precipitation datasets. After filtering out where assumptions of may been compromised, 98,568 estimates produced. The resulting 17 spatial integrated into a random forest regression algorithm, generating high-resolution (0.05°) model reveals that climate-related variables, including precipitation, rainfall seasonality, potential evapotranspiration, exert most significant influence on rates, with vegetation (NDVI) also contributing significantly. Importantly, both mean values point dataset (43.5 mm y-1) (22.7 are notably lower than those reported in previous studies, underscoring prolonged timescale CMB disparities arising from methodologies. This study presents robust automated approach method, offering unified based single method. datasets, Python script for rate calculation, models collectively provide valuable insights water resources management Australian continent similar approaches can be applied globally.