The Most Common Stream Width is Remarkably Invariant with Changes in Hydrologic Conditions

Headwater streams, despite being a significant natural resource, and a critical element of the hydrosphere, remain an understudied system. Anyone who has observed small creeks and rivers closely will know that stream width is highly variable, and depends on the hydrological conditions in the catchment. Stream width (and by extension, surface area) is a critical parameter for a number of important hydrological and biogeochemical processes. Even so, to date there is no consistent study of dynamic stream widths throughout an entire headwater catchment. Here are presented data and observations documenting the spatial and temporal variability of stream width in a single 0.484 km2 headwater catchment in central North Carolina, USA. The frequency distribution of stream widths in the catchment follows a lognormal distribution. Two opposing processes that scale with discharge impact the width distribution. One is at-a-point stream widening, and the other is dynamic network expansion. Despite high spatial and temporal width heterogeneity, the width distribution is remarkably stable with discharge, with a mode width that lies in a narrow range. These results suggest that at-a-point widening and network expansion are roughly in balance, and the relative impacts of each are analyzed.Bachelor of Scienc