37 Innovations in Research of Groundwater-Surface Water Interactions over Multiple Spatio-Temporal Scales

This session will focus on fluxes of water and solutes between groundwater and surface water, which play a crucial role in freshwater supplies for humans and ecosystems.

Sunday, 19 October 2025
1:30 PM - 5:30 PM
HBGCC, 209

Exploring the Variability of Baseflow Drought Through Diel Paired Air-Stream Temperature Analysis

Paper number: 37-13
Program: Technical Sessions
Time: 3:18 PM – 3:38 PM

Authors

Abstract

Understanding baseflow dynamics is crucial for assessing the resilience of watershed ecosystems to climate change. Recent studies have highlighted the significance of groundwater-derived baseflow during snowmelt and its critical role during extended low-flow conditions. However, baseflow dynamics often show remarkable heterogeneity within single watersheds, and baseflow droughts can be lagged in comparison to meteorological droughts, emphasizing the need for sub-annual and inter-annual analyses. We present uses of the paired diel air–stream temperature analysis using sub-annual timeseries to uncover intra-annual and interannual dynamics related to low-flow periods as well as meteorological drought. We demonstrate the application of this method for monitoring stream drought responses, complemented by varied additional sampling across a range of temperate sites with varying flow regimes. Our findings support that groundwater-dominated stream networks often show the strongest decoupling during summer low-flow periods, and our multi-year results indicate that groundwater connectivity can increase in some streams during meteorological drought conditions, while others remained stable or declined. These methods show that the spatiotemporal response of baseflow varies across stream networks, drawing attention to stable groundwater flux or the signaling of low dynamic storage reservoirs and imminent groundwater disconnection. Beyond stream temperatures' bio-geo-chemical importance, temperature dynamics have long been shown to be a key methodology to understanding stream and watershed processes. The use of stream temperature methods, due to their affordability, temporal resolution, and ease of collection, continues to prove a supportive method for watershed and stream studies. The diel paired temperature analysis is now an additional method for the toolbelt.

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

doi: 10.1130/abs/2025AM-413049

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