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Hyporheic exchange is often controlled by subsurface advection driven by the interaction of the stream with sedimentary pore water. The nature and magnitude of the induced exchange flow is dependent on the characteristics of both the stream flow and the sediment bed. Fundamental hydrodynamic theory can be applied to determine general relationships between stream characteristics, sediment characteristics, and hyporheic exchange rates. When the stream bed is fine enough to allow application of Darcy's Law, as with sand beds, the induced advective exchange can be calculated from fundamental hydrodynamic principles. Comparison with a wide range of experimental results demonstrates the predictive capability of this theory. Coarser sediments such as gravels are more complex because they admit turbulent interactions between the stream and subsurface flows, which can produce considerable …