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Jesus D Gomez-Velez

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Abstract Hydrologic exchange fluxes (HEFs) vary significantly along river corridors due to spatio-temporal changes in discharge and geomorphology. This variability results in the emergence of biogeochemical hot-spots and hot-moments that ultimately control solute and energy transport and ecosystem services from the local to the watershed scales. In this work, we use a reduced-order model to gain mechanistic understanding of river bank storage and sinuosity-driven hyporheic exchange induced by transient river discharge. This is the first time that a systematic analysis of both processes is presented and serves as an initial step to propose parsimonious, physics-based models for better predictions of water quality...
Categories: Publication; Types: Citation
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Abstract Downstream flow in rivers is repeatedly delayed by hydrologic exchange with off‐channel storage zones where biogeochemical processing occurs. We present a dimensionless metric that quantifies river connectivity as the balance between downstream flow and the exchange of water with the bed, banks, and floodplains. The degree of connectivity directly influences downstream water quality--too little connectivity limits the amount of river water exchanged and leads to biogeochemically inactive water storage, while too much connectivity limits the contact time with sediments for reactions to proceed. Using a metric of reaction significance based on river connectivity, we provide evidence that intermediate levels...
Categories: Publication; Types: Citation
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Abstract New experimental techniques are allowing, for the first time, direct visualization of mass and momentum transport across the sediment‐water interface in streams. These experimental insights are catalyzing a renaissance in our understanding of the role stream turbulence plays in a host of critical ecosystem services, including nutrient cycling. In this commentary, we briefly review the nature of stream turbulence and its role in hyporheic exchange and nutrient cycling in streams. A simple process‐based model, borrowed from biochemical engineering, provides the link between empirical relationships for grain‐scale turbulent mixing and nutrient processing at reach, catchment, continental, and global scales....
Categories: Publication; Types: Citation
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Data Release from the High-Flow Field Experiments to Inform Everglades Restoration: Experimental Data 2010 to 2018. Data were obtained from field sites located in the Everglades between two canals (L-67A and L-67C) from 2010 to 2018. During this time, five major controlled flow releases occurred by opening the culvert S152 on canal L-67A. Data consist of water velocity (continuous and discrete), water levels (continuous and discrete), suspended sediment concentration, load and flux (discrete), suspended phosphorus concentration, load and flux (discrete), grainsize distribution (continuous and discrete), biogeochemistry (discrete), water quality (continuous), temperature (continuous) and vegetation (discrete).
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Increasing nitrogen concentrations in the world’s major rivers have led to over-fertilization of sensitive downstream waters. Flow through channel bed and bank sediments acts to remove riverine nitrogen through microbe-mediated denitrification reactions. However, little is understood about where in the channel network this biophysical process is most efficient, why certain channels are more effective nitrogen reactors, and how management practices can enhance the removal of nitrogen in regions where water circulates through sediment and mixes with groundwater-hyporheic zones. Here we present numerical simulations of hyporheic flow and denitrification throughout the Mississippi River network using a hydrogeomorphic...
Categories: Publication; Types: Citation
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