Local and Valley-Scale Controls on the Physical Patterns of Groundwater-Surface Water Interactions
Abstract
Groundwater discharge zones along river networks can stabilize low flows and provide thermal refuge for biotic communities but also act as conduits of legacy pollutants. Unfortunately, efforts to protect and manage groundwater-dependent stream habitats are limited by our ability to characterize and predict their spatial distributions along river corridors. Characterization of groundwater distribution patterns requires contiguous and expansive, yet finely resolved, survey data in order to assess both localized (e.g. bank and hillslope), and broad, valley-scale drivers (e.g. confinement). To address these challenges, we conducted bank side surveys of 5th order sections of the Housatonic River, MA, USA (12km), and the Farmington River, CT, USA (26km) in summer 2019 using handheld thermal infrared cameras to identify thermal anomalies indicative of groundwater discharge. We performed a multi-scale sliding window analysis leveraging public, remotely-sensed datasets such as high resolution (1m) LiDAR-derived digital elevation models to characterize local and valley-scale features and assess their explanatory capacity and predictive accuracy regarding the absence and presence of groundwater discharge along the river corridor. Features that best predict observed discharge were identified through a multivariate analysis. On the valley-scale, findings suggest river sections in partially-unconfined valley settings were associated with more extensive groundwater discharge zones than their unconfined and confined counterparts. On a localized scale, however, features such as steep bank side slopes indicate groundwater discharge across a variety of valley-scale settings.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMH130...08J
- Keywords:
-
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0470 Nutrients and nutrient cycling;
- BIOGEOSCIENCES;
- 1830 Groundwater/surface water interaction;
- HYDROLOGY;
- 1871 Surface water quality;
- HYDROLOGY