234-2 Quantifying Climate Change-Driven Alterations of Groundwater Recharge using Space-Based Hydrologic Observations

Session: Advance Ground Surface Modeling for Hydrological and Environmental Applications

Presenting Author:

Author:

Abstract:

The objective of this work is to create a straightforward, easy to use and reliable groundwater recharge estimation technique, based on the combined use of cutting-edge remote sensing hydrologic observations and a robust hydrologic model. This approach provides continuous, in both space and time, groundwater recharge estimates of high fidelity. Satellite-based high spatio-temporal resolution precipitation estimates are also used to derive a robust precipitation-groundwater recharge empirical relationship that will provide significant insight into the impact of climate variability, and the resulting intensification of the water cycle, on groundwater recharge dynamics.

Specifically, a model-data fusion scheme is created by assimilating NASA’s Gravity Recovery and Climate Experiment (GRACE) and GRACE-Follow-On (GRACE-FO) observations of total water storage anomalies into the augmented groundwater version of the widely used Variable Infiltration Capacity hydrologic model (VIC-4L). All satellite data are publicly available and are characterized by monthly temporal resolution and a global coverage. The VIC-4L model-data fusion framework, focusing on regions west of longitude 100 W in the state of Texas, efficiently fuses the downscaled (via data assimilation) GRACE/GRACE-FO observations with the model’s water table depth estimates to generate improved water table daily fluctuations, which yield optimized and reliable groundwater recharge estimates and dynamics at the 1/16th degree (~6.7 km). These enhanced groundwater recharge estimates reflect major human interventions, such as groundwater pumping and irrigation, as GRACE/GRACE-FO data are assimilated in the model. Daily precipitation, at the 10 km spatial resolution, derived from NASA's Global Precipitation Measurement (GPM), specifically the Level 3 IMERG (Integrated Multi-satellitE Retrievals for GPM) product is used for the precipitation-groundwater recharge empirical relationship, and therefore, the groundwater recharge simulated product is resampled to the 10-km grid to match the precipitation dataset's spatial resolution.

This work will derive a long-term relationship between precipitation trends and groundwater levels in the context of climate change, and will better quantify and predict the impact of climatic variability on groundwater recharge dynamics in the arid and semi-arid regions of Texas. Moreover, the unprecedentedly high spatiotemporal resolution of the generated recharge estimates will facilitate the adjustment of local water resource management and planning strategies in the Texas drylands, in the context of climate change. Finally, this work is characterized by scalability and extensibility, with applications in water resources management worldwide.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9258

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.