This study reviewed the applicability of the existing flood discharge calculation method on Jeju Island Han Stream and compared this method with observation results by improving the mediating variables for the Han Stream. The results were as follows. First, when the rain-discharge status of the Han Stream was analyzed using the flood discharge calculation method of the existing design (2012), the result was smaller than the observed flood discharge and the flood hydrograph differed. The result of the flood discharge calculation corrected for the curve number based on the terrain gradient showed an improvement of 1.47 - 6.47% from the existing flood discharge, and flood discharge was improved by 4.39 - 16.67% after applying the new reached time. In addition, the sub-basin was set separately to calculate the flood discharge, which yielded an improvement of 9.92 - 32.96% from the existing method. In particular, the steepness and rainfall-discharge characteristics of Han Stream were considered in the reaching time, and the sub-basin was separated to calculate the flood discharge, which resulted in an error rate of –8.77 to 8.71%, showing a large improvement of 7.31 - 28.79% from the existing method. The flood hydrograph also showed a similar tendency.

Abstract
 1. 서 론
 2. 연구방법
  2.1. 연구대상지역
  2.2. 적용 호우사상
  2.3. 홍수량 산정방법
  2.4. 유역특성에 따른 매개변수 보정
  3. 결과 및 고찰
   3.1. 기존 홍수량 산정요령에 의한 분석결과
   3.2. 매개변수 보정에 의한 홍수량 결과
   3.3. 보정 매개변수 조합에 따른 홍수량 산정
   4. 결 론
  감사의 글
  REFERENCES

• 양성기(제주대학교 토목공학과) | Sung-Kee Yang Corresponding author
• 김민철(제주대학교 토목공학과) | Min-Chul Kim
• 강보성(제주대학교 토목공학과) | Bo-Seong Kang
• 김용석(제주대학교 토목공학과) | Yong-Seok Kim
• 강명수(제주대학교 토목공학과) | Myung-Soo Kang