Current-topography driven exchange processes between water columns and heterogeneous permeable sediments M. Bayani Cardenas, Department of Geological Sciences, University of Texas at Austin We are investigating the effects of sediment permeability (k) architecture on solute and heat exchange across the sediment-water interface in riverbeds and banks using computational modeling and lab experiments. The figure to the right shows how a sinuous channel induces flow through the banks for the channel as indicated by water table contours to which groundwater flow is perpendicular to. The figure to the left shows how parts of a streambed warm up and cool down differently in response to river warming and cooling. The difference is due to fluid flow in the sediment which carries the heat which is controlled by streambed topography.