Abstract
Transitions in channel pattern are often assumed to reflect differences in sediment supply.  However, we (river scientists) have had limited success determining where such transitions should occur, largely because we lack the data necessary to quantify the supply.  The question addressed here is whether there are important differences in the variables governing sediment transport capacity (width, depth, slope and grain size) that would help explain the transition from single-thread to braided channel patterns.  The results presented suggest that the seemingly large difference in bed load transport capacity of braided and single-thread channels is due primarily to differences in transport intensity, driven by lower thresholds for transport in braided rivers characterized by a very wide range of grain sizes, including sand.