Channel-forming Discharge Evaluation for Rivers with High Coefficients of River Regime

Abstract

The channel-forming discharge, which is a standard and single flow for the river maintenance and restoration project, should be estimated necessarily in the stable channel design. It is difficult to produce the specific pattern for the channel-forming discharge in the domestic rivers due to the insufficient researches and case studies. Also, it is improper to adopt the foreign cases for the domestic rivers and streams which have the high coefficients of river regime. Therefore, the channel-forming discharge possible to use for rivers with high coefficients of river regime is suggested in this study through analyzing the bankfull, specified recurrence interval, and effective discharges of Mangyeong River, Cheongmi Stream, and Hampyeong Stream for the abandoned channel restoration project. The bankfull discharge was calculated with geometric data using the HEC-RAS modeling and the flow, bed materials, and sediment data for the study reaches were used to estimate the specified recurrence interval and effective discharges. As a result for calculating the channel-forming discharge, the effective discharge was greater than the bankfull discharge in the river with high coefficient of river regime and the effective discharge was greater than the bankfull and there was no correlation between the coefficient of river regime and the characteristics of the specified recurrence interval discharges.