| Title |
Discharge Computation from Float Measurement in Vegetated Stream |
| Authors |
이태희(Lee, Tae Hee) ; 정성원(Jung, Sung Won) |
| DOI |
https://doi.org/10.12652/Ksce.2019.39.2.0307 |
| Keywords |
식생하천;부자;수위-유량관계;유속-면적법;도복상태;식생층;통수단면적 Vegetated stream;Float measurement;Stage-discharge relationship;Velocity-area method;Prone;Vegetation layer;Flow area |
| Abstract |
Development of vegetation in stream channel increases resistance to flow, resulting in increase in river stage upon flood and affecting change in stage-discharge relationship. Vegetation revealed in stream by water level reaching a peak and then declined upon flood is mostly found as prone. Taking an account of flow distribution with the number of vegetation, prone vegetation layer might be at height where discharge rate is zero (0) (Stephan and Guthnecht, 2002). However, there is a tendency that flow rate is overestimated when applying the height of river bed to flow area with no consideration of the height of vegetation layer in flow rate by float measurement. In this study, reliable flow measurement in stream with vegetation was calculated by measuring the height of vegetation layer after flood and excluding the vegetation layer-projected area from the flow area. The result showed the minimum 4.34 % to maximum 10.82 % of flow deviation depending on the scale of discharge. Accordingly, reliable velocity-area methods would be determined if vegetation layer-projected area in stream is considered in flow rate estimation using the flow area during the flood. |