Development of seawater inflow equations considering density difference between seawater and freshwater at the Nakdong River estuary

Jeong, Seokil, Lee, Sanguk, Hur, Young Teck, Kim, Youngsung, Kim, Hwa Young

doi:10.3741/JKWRA.2022.55.5.383

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2022 Vol.55, Issue 5 Preview Page

Research Article

Development of seawater inflow equations considering density difference between seawater and freshwater at the Nakdong River estuary 해담수 밀도차를 고려한 낙동강하굿둑 해수유입량 산정식 개발

31 May 2022. pp. 383-392

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Abstract

낙동강하굿둑 기수역의 복원이 국정과제로 채택되면서, 2019~2020년의 실증실험과 2021년 시범운영을 거쳐 2022년 기수역 복원이 공식화 되었다. 해수유입 시 많은 의사결정이 실시간으로 수행되어야 하므로, 실측과 수치해석을 이용한 의사결정시스템이 체계화되었으며, 이 과정에서 정확한 해수유입량 산정이 필요하였다. 이에 본 연구에서는 해수와 담수의 밀도차이와 낙동강하굿둑 수문의 구조적인 특성을 반영한 해수유입량 산정식을 개발하였다. 낙동강하굿둑 수문은 월류와 저류방식으로 해수유입이 가능하므로, 산정식 또한 두 가지 형태로 제시하였다. 개발된 식의 정확도 확인 및 유량계수 도출을 위하여 시범운영 기간동안 ADCP를 이용하여 해수유입량을 실측하였다. 완성된 식을 이용한 계산값과 실측값의 비교 결과 약 3%의 오차를 확인하였다.

키워드

낙동강하굿둑

해수유입

산정식

저류

월류

유량 실측

The restoration of the Nakdong River estuary is one of the most important projects of the Ministry of Environment, Republic of Korea. A real-scale experiment of gate operation was executed from 2019 to 2020, and a pilot operation was performed in 2021. The gate of Nakdong River Estuary Barrier (NEB) is supposed to be continuously opened based on the experiment results. Many critical decisions should be made immediately during the experiment based on the real-time measured data and numerical analysis considering the seawater inflows. The decision-making sequence was made systematically with the accurate estimation of seawater inflow. The estimation of seawater inflow is the main research objective and the equations of seawater inflow were developed, reflecting the structural characteristics of NEB. The inflow equations were developed in two forms, overflow and underflow. ADCP (Acoustic Doppler Current Profiler) was used to measure seawater inflow, check the accuracy of the developed equations, and derive the flow coefficient. The comparison error of the developed equations was about 3% compared to the measured data.

Keywords

Nakdong River estuary barrier

Seawater-inflow

Equations

Underflow

Overflow

Measured discharge

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Information

Publisher :KOREA WATER RESOURECES ASSOCIATION
Publisher(Ko) :한국수자원학회
Journal Title :Journal of Korea Water Resources Association
Journal Title(Ko) :한국수자원학회 논문집
Volume : 55
No :5
Pages :383-392
Received Date :2022. 04. 11
Revised Date :2022. 04. 29
Accepted Date : 2022. 04. 29
DOI :https://doi.org/10.3741/JKWRA.2022.55.5.383

Journal of Korea Water Resources Association ISSN:2799-8746(Print) 2799-8754(Online) 한국수자원학회 논문집

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