Geomorphic and Sedimentological Controls on Hyporheic Flow in an Alpine River
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Date
2020-05
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The Ohio State University
Abstract
The hyporheic zone, where surface water enters the riverbed and mixes with groundwater, affects surface water quality. Variations in streambed morphology and sediment characteristics in meandering rivers lead to heterogeneity in hyporheic exchange, with flow paths that range in scale from centimeters to hundreds of meters. To assess controlling factors for hyporheic exchange in a 200-m reach of a meandering alpine river, forty-three sediment samples were analyzed for grain size in East River, Colorado (USA). Additionally, vertical hydraulic head gradients were measured at eighty locations. A ground-penetrating radar survey was also used to characterize streambed morphology. In this predominantly gravel stream, the meander and pool-riffle morphology control large-scale patterns of hyporheic flow, while variations in grain size and permeability appear to play a smaller, modifying role. These results will improve flow and reactive transport models over dynamic flood and base flow conditions at the intensively studied field site and improve the understanding of the interplay between hyporheic flow and streambed characteristics.
Description
Geological Society of America Hydrogeology Section Poster Award - Nov 2018
Keywords
hyporheic zone, hydrogeology, surface water-groundwater interactions, geomorphology, sedimentology