An in situ daily dataset for benchmarking temporal variability of groundwater recharge

Abstract. Accurate estimate of groundwater recharge is crucial for prediction of groundwater table dynamics and dependent eco-hydrological processes. Despite their importance, benchmark data for groundwater recharge at fine (∼ daily) temporal resolution are lacking. We present a first-of-its-kind daily groundwater recharge per unit specific yield (RpSy) data over periods of 2–38 years at 485 groundwater monitoring wells in the US. The RpSy data for these locations are calculated from the daily groundwater table time series using the water table fluctuation (WTF) method. Although direct validation of the data is not possible since it is the first of its kind, we compare the RpSy data with the monthly USGS product to identify similarities and differences. The RpSy dataset may serve as a benchmark for validating the temporal consistency of recharge products and daily simulation results from land surface and integrated hydrologic models. The dataset is available at https://doi.org/10.5281/zenodo.13323242 (Malakar et al., 2024).