Enhancing Drought Projections and Water Resource Management in the Great Artesian Basin Using GRACE-Based TWS Data and Climate Model Integration

The Great Artesian Basin (GAB), one of the world’s largest groundwater reservoirs, is facing increasing pressures due to climate variability and change. Accurate projections of water resource availability and drought risk in the GAB region require advanced modeling techniques that integrate both observed and simulated hydrological data. This study emphasizes the contribution of GRACE (Gravity Recovery and Climate Experiment) satellite data in enhancing climate models and improving projections of Terrestrial Water Storage (TWS) for drought assessments.

GRACE provides independent measurements of TWS, capturing both surface and subsurface water components, such as soil moisture and groundwater. This unique capability makes GRACE an invaluable tool in calibrating and validating hydrological models, particularly for deep water storage, which is crucial for understanding long-term drought impacts. GRACE data is used to refine climate models from CMIP5 and CMIP6 ensembles, focusing on their predictive capability for groundwater and deep soil moisture under varying climate scenarios.

By integrating GRACE-derived TWS data with CMIP model outputs, the models are calibrated using a multi-model weighting method that accounts for both the skill (based on RMSE) and independence (based on pairwise distance) of each model. This process improves the reliability of future TWS projections, specifically for drought forecasting and water resource management in semi-arid regions like the GAB.

This study demonstrates how GRACE data significantly enhances the accuracy of hydrological modeling and climate projections for water resources, especially in the context of climate change. The findings highlight the value of integrating satellite observations with climate models to improve drought projections and build resilience in the GAB and similar regions globally.