The sand dunes of the Colorado River, Grand Canyon, USA

The flow (Wright and Kaplinski, 2011), suspended sediment transport (Topping et al., 2000), sediment storage (Grams et al., 2013), and sedimentology of sandbars (Rubin et al., 1998) of the 250 miles of the Colorado River that run through Grand Canyon National Park have been well studied and described. However, there has been little systematic or synoptic description of the morphologies and sedimentology of the riverbed, where at least 80 percent of the active sand occurs (Grams et al., 2013). Here, we use high-resolution bathymetric and backscatter measurements collected with multibeam echosounder to comprehensively describe the morphology, sedimentology, and kinematics of sand dunes, and to estimate bedload sediment transport in certain reaches of the river.