Streamflow Characteristics from Channel Size

Flood-peak-frequency characteristics and mean flows of ungaged streams can be estimated from field measurements of channel width using relations based on data at gaged sites. Such relations have been developed by many investigators and are shown to be in good agreement. The technique, an engineering application of research in channel morphology, is most useful in regions where traditional methods may produce unreliable results. The need for better estimates of flow characteristics in the semiarid regions of western United States led the United States Geological Survey to develop and publish estimating relations, and to establish guidelines (so far as possible) for measuring channel width. The paper describes practices and results by the USGS and others, evaluates the reliability of the technique, and suggests possible improvements.