Rainfall-runoff model of Jeju Oedo Stream was used to compute the optimal unit hydrograph by HEC-HMS model that reflecting on watershed characteristics. Each rainfall event was comparatively analyzed with the actual flow measurement using Clark, Snyder and SCS synthetic methods for derived unit hydrograph. Subsequently, the null hypothesis was established as p-value for peak flow and peak time of each unit hydrograph by one-way ANOVA(Analysis of variance) was larger than significance level of 0.05. There was no significant difference in peak flow and peak time between different methods of unit hydrograph. As a result of comparing error rate with actual flow measurement data, Clark synthetic unit graph best reflected in Oedo Stream as compared to other methods, and error rate of Clark unit hydrograph was 0.02~1.93% and error rate at peak time was 0∼2.74%.

Abstract
 1. 서 론
 2. 자료 및 방법
  2.1. 연구방법
  2.2. 연구대상 유역
  2.3. 입력자료 선정
 3. 결과
  3.1. 홍수유출량 산정
  3.1. 단위유량도 유의성 분석
 4. 결론
 REFERENCE

• 이준호(제주대학교 토목공학과) | Jun-ho Lee (Department of Civil Engineering, Jeju National University)
• 양성기(제주대학교 토목공학과) | Sung-Kee Yang (Department of Civil Engineering, Jeju National University) Corresponding author
• 정우열(제주대학교 토목공학과) | Woo-Yul Jung (Department of Civil Engineering, Jeju National University)