Roughness coefficient was computed for review of applicability based on measurement of the representative grain diameter reflecting channel characteristics of Han Stream. After field survey, collection of bed material, and grain analysis on the collected bed material, roughness coefficient was computed using representative grain and existing empirical equation for roughness coefficient. Value of roughness coefficient calculated using equation by Meyer-Peter and Muller (1948) was 0.0417 for upstream, 0.0432 for midstream, and 0.0493 for downstream. As a result of comparing the computed roughness coefficient to other empirical equations for review of applicability, the coefficient was larger in Strickler (1923) equation by 0.006. Smaller coefficient was shown by Planning Report for River Improvement Works. Equation by Garde and Raju (1978) was larger by 0.004, and equations by Lane and Carlson (1953) and by Meyer-Peter and Muller (1948) were larger by 0.001. Such precise roughness coefficient is extremely important when computing the amount of flood in rivers to prevent destruction of downstream embankments and property damages from flooding. Since roughness coefficient is a factor determined by complicated elements and differs according to time and space, continued management of roughness coefficient in rivers and streams is deemed necessary.

Abstract
 1. 서 론
 2. 연구자료
 3. 연구방법
  3.1. 조도계수 경험식
  3.2. 조도계수 산정과정
  3.3. 하상재료 채취방법
  3.5. 입도분포 시험
 4. 결과 및 고찰
  4.1 조도계수 산정
  4.2. 조도계수의 비교
 5. 결 론
 참 고 문 헌

• 양성기(제주대학교 토목공학과) Corresponding author
• 이준호(제주대학교 토목공학과)
• 김동수(단국대학교 토목환경공학과) | Dong-su Kim (Department of Civil & Environmental Engineering, Dankook University)