Multi-regional water supply system, which installed for supplying multiple water demands, is characterized by large-sized, long-distance, tree-type layout. This system is vulnerable to long-standing service interruption when a pipe breaks is occurred. In this study, a numerical method is proposed to calculate drainage time that directly affects time of service interruption. To begin with, governing equations are formulated to embed the delayed drainage effect by the friction loss, and to resolve complicated connection of pipelines, which are derived from the continuity and energy equations. The nonlinear hydraulic equations are solved by using explicit time integration method and the Newton-Raphson method. The developed model is verified by comparing the result with analytical solution. Furthermore, the model’s applicability is validated by the examples of pipelines in serial, in parallel, and complex layout. Finally, the model is utilized to suggest an appropriate actions to reduce the deviation of draining time in the C transmission line of the B multi-regional water supply system.

1. 서 론
 2. 관로의 배수시간 산정을 위한 지배방정식
  2.1 관로의 배수시간 산정을 위한 이론식
  2.2 마찰을 고려한 배수시간 산정식의 유도
  2.3 복합 연결상태를 가지는 관로에 적용을 위한 일반식의 유도
 3. 시간적분법을 이용한 배수시간 산정모형개발
  3.1 비선형 방정식의 수치근사해 결정
  3.2 시간적분법을 이용한 배수시간의 수치해석
 4. 배수시간 산정 수치해석 모형의 검증및 적용
  4.1 단일관로 해석해와의 검증
  4.2 직렬연결 관로의 수치해석 결과
  4.3 직렬과 병렬 관로가 혼합하여 연결된 관로의 수치해석 결과
  4.4 광역상수도 실제운영 사례에 대한 적용결과
 5. 결 론
 References

• 신병호(한국수자원공사 수도권수도건설단장, Korea Water Resources Corporation) | Shin, Byoung-Ho
• 최두용(한국수자원공사 K-water 융합연구원 수석연구원, Head Researcher, K-water Institute, Korea Water Resources Corporation) | Choi, Doo-Yong
• 정관수(충남대학교 토목공학과 교수, Rofessor, Chungnam National University) | Jeong, Kwansue Corresponding author