COMPARING THE HYDRAULIC GEOMETRY OF RIVERS, SUBAQUEOUS CHANNELS, AND EXTRATERRESTRIAL FLUVIAL FEATURES

Hydraulic geometry analysis, classically applied to river channels, seeks to find scaling relationships for the hydraulic dimensions of a flow as discharge is varied. These empirically derived relationships provide insight into the dynamic interaction between the physical processes of channelized flows and channel form across the range of fluvial scales. Although hydraulic geometry analysis has been applied successfully to river channels, few studies have identified hydraulic scaling relationships for other types of channelized flows. With recent advances in technology, detailed topographic maps of subaqueous channels, as well as remotely sensed images of extraterrestrial channel features, are now becoming readily available. These subaqueous and extraterrestrial channels show striking similarities to their fluvial counterparts, such as dendritic drainage networks identified on Titan (Soderblum et al., 2007) and meandering channels, levees, and cutoffs on the Amazon submarine channel (Pirmez & Flood, 1995). In this study, we use this newly available data to systematically compare the bankfull hydraulic geometry of channelized flows from a range of environments and scales. Under the assumption that these flows operate under the same driving and resisting forces as rivers, we use the Chezy equation to estimate formative discharge conditions. We then identify scaling relationships that hold well for a variety of channel types, suggesting that the formative conditions are governed by similar processes.