UC Santa Barbara

Groundwater is a fundamental resource for humans and represents a major volumetric phase of the terrestrial water cycle. Observations indicate that climate change is altering precipitation patterns globally and inducing an increase in the frequency and magnitude of extreme events. These extreme precipitation events may buffer water resources long-term in the face of increasing droughts by contributing significant recharge to aquifers. Nonetheless, uncertainties remain regarding the influence of local geological variability and the unpredictability of regional weather patterns on extreme precipitation induced groundwater recharge at the catchment scale. This complexity necessitates further exploration and requires both targeted testing and extended observational studies. This study applied interferometric synthetic aperture radar (InSAR) to characterize groundwater fluxes in the ungauged endorheic basin Death Valley, California, from December 2018 through December 2023. Over this period there was mean upward vertical displacement (uplift) of ~1.5 to 2 cm across the basin caused by recharge. T-mode principal component analysis was used to isolate dominant deformation signals coinciding with extreme precipitation events. This study demonstrates the applicability of InSAR as a viable tool to assess groundwater fluxes in response to precipitation variability, furthering our understanding of terrestrial water cycling in a warming world.