Rivers are the veins of the landscape, providing environmental benefits that are disproportionately high relative to their aerial extent; shedding flood waters, hosting aquatic ecosystems, transporting solutes and energy-rich materials, and storing and transforming pollutants into less harmful forms. From uplands to the coasts, rivers facilitate key biogeochemical reactions that cumulatively influence water quality. Many of the reactions are optimized outside the main channel, in hyporheic zones, riparian zones, and floodplain areas, where riverine water is in close contact with geochemically and microbially-active sediments. However, little is known about the distribution, intermittency, and overall effectiveness...
