Hydrologic characteristics of a small desert mountain stream: implications for short-term magnitude and frequency of bedload transport

Hydrologic data indicate that flow occurred in this channel only 0.05% of the time. The probability density function of flow is distinctly non-lognormal and approximates a one-parameter gamma distribution due to the lack of base flow. Estimation of bedload transport for the flows indicates that the effective discharge for transport is probably equalled or exceeded only about 0.01% of the time, but may have a recurrence interval of approximately 2.5 years. A close correspondence between estimated bankfull flow of the active channel and the effective discharge suggests that equilibrium between form and process occurs in this system. However, because the active channel lies within an arroyo, other factors, such as catastrophic floods, appear to shape the gross channel morphology which is in disequilibrium with the short-term hydrologic regime. -from Author