Work

Groundwater storage changes in the United States using baseflow recession method: Comparison with GRACE and well observations

Year: 2025

Type: article

Abstract: Groundwater serves as a critical source of water supply in regions where surface water availability is scarce. Globally, more than one-third of the water used originates from underground. However, excessive dependence on this resource has led to significant depletion of several aquifers across the United States, though some aquifers have experienced rising water levels due to intensive recharge initiatives. A thorough assessment of the changing rates of groundwater storage is crucial for evaluating its future availability. Baseflow magnitude is an important visible indicator of groundwater storage extent in shallow aquifers. This study examines the spatial and temporal variability in baseflow recession characteristics across more than a thousand watersheds within the contiguous United States (CONUS). Groundwater storage changes are quantified using a recently developed algorithm that extracts baseflow events from streamflow and precipitation observations. The storage changes estimates obtained through this approach are compared with the estimates from the GLDAS 2.2 GRACE-DA, a satellite-based data and those from well level observations. All the three methods provide insights into groundwater storage variations over time, though at different spatial and temporal scales, with some inherent advantages and limitations. Over 75% of watersheds show consistent trends between baseflow-derived and GRACE-based storage estimates, while 65% align with well observations. These findings demonstrate the method's suitability for estimating groundwater storage in free-flowing, minimally disturbed basins, especially where long-term monitoring is limited.

Source: Journal of Hydrology Regional Studies

DOI: 10.1016/j.ejrh.2025.102946

Authors: Mehvish Hameed, Munir Ahmad Nayak, Manzoor Ahmad Ahangar

Institution: National Institute of Technology Srinagar

Language: English

Topic: Geophysics and Gravity Measurements

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Clean water and sanitation, Climate action

Open Access status: gold

Estimated APC paid: $2,600