| Title |
Determination of Resistance Coefficients Using Field Measurements in Natural Rivers |
| DOI |
https://doi.org/10.12652/Ksce.2012.32.2B.139 |
| Keywords |
저항계수;자연하천;반 경험적 방법;무차원 유속;저항계수 관계식 resistance coefficients;natural rivers;semi-empirical method;dimensionless velocity;resistance coefficient relationships |
| Abstract |
This study is derived relationships of the resistance coefficients of Darcy-Weisbach and Manning for flow resistance and the dimensionless velocity using many field measurements for 1,875 rivers consist of sand 179, gravel 992, cobble 651 and boulder 53 channels in natural rivers, respectively. The relationships of power law forms are developed as a function of flow discharge, friction slope, and relative submergence by the regression and the semi-empirical method. The measurements distribution of Manning resistance coefficients by the Box-Whisker Plots show the values which ranges from 0.004~0.151 for sand, 0.008~0.250 for gravel, 0.015~0.327 for cobble, 0.023~0.444 for boulder in natural rivers, respectively. Relationships of these semi-empirical and resistance coefficients will be useful to give information in hydraulic engineering. |