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2025 Vol.58, Issue 12 Preview Page

Research Article

Development of a water quality assessment framework using multi­standard load duration curves

다수질기준 부하지속곡선을 활용한 수질평가 프레임워크 개발

Jaehyeong Kima
,
Kyungmin Kimb
,
Juseong Leec
,
Minah Kimc
,
Jinsun Kimd
,
Minji Parke
,
Hanseok Jeongf*
김 재형a
,
김 경민b
,
이 주성c
,
김 민아c
,
김 진선d
,
박 민지e
,
정 한석f*
aIntegrated B.S.-M.S. Program, Department of Environmental Engineering, Seoul National University of Science and Technology, Seoul, Korea
bDoctoral Student, School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona, USA
cDoctoral Student, Department of Environmental Engineering, Seoul National University of Science and Technology, Seoul, Korea
dResearcher, Measurement and Analysis Division, Han River Basin Environmental Office, Ministry of Climate, Energy and Environment, Hanam, Korea
eResearcher, Geum River Environment Research Center, National Institute of Environmental Research, Okcheon, Korea
fAssociate Professor, Department of Environmental Engineering, Seoul National University of Science and Technology, Seoul, Korea
a서울과학기술대학교 환경공학과 학석사연계과정
b애리조나주립대학교 지속가능공학 및 건축환경공학부 박사과정
c서울과학기술대학교 환경공학과 박사과정
d기후에너지환경부 한강유역환경청 측정분석과 연구사
e국립환경과학원 금강물환경센터 연구사
f서울과학기술대학교 환경공학과 부교수
*Corresponding Author
31 December 2025. pp. 1337-1349
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Abstract

A load duration curve (LDC) illustrates the relationship between streamflow and both observed and target pollutant loads. LDCs are widely used to diagnose water quality conditions, evaluate the effectiveness of water quality management strategies, and assess the achievement of water quality goals. In the current Total Maximum Daily Load management plan, water quality assessments are based on LDCs and exceedance rates of target water quality standards across flow regimes. However, these assessments only consider whether the standards are exceeded, without reflecting the extent of exceedance, which may lead to misinterpretations. To address this limitation, this study proposes an enhanced water quality assessment framework that incorporates multi-standard LDCs, the proportional distribution of water quality grades, and the rate of change in the proportion of “Good quality” water. We applied the framework to the Cheongmicheon in the Hangang basin to evaluate its practical applicability. The results demonstrate that multi-standard LDCs enable intuitive assessment of the distribution of observed loads across water quality grades and the degree of pollution. Additionally, analyzing the proportional distribution of water quality grades makes it possible to identify persistent occurrences of lower water quality grades, detect temporal trends in stream water quality, and characterize water quality conditions while accounting for differences across monitoring stations. Furthermore, when evaluating stream water quality across different flow regime divisions, the differences in the proportion of “Good quality” water were minimal. This study confirms that multi-standard LDCs can provide richer information than conventional LDCs and serve as a useful tool for stream water quality assessment and policy decision-making.

Keywords
Water quality standards
Distribution of water quality grades
Water quality management
Exceedance rate
Cheongmicheon

부하지속곡선은 유량에 따른 관측부하량과 목표부하량의 관계를 나타내는 곡선으로, 수질오염상태의 진단뿐만 아니라 수질관리 대책에 따른 효과 분석 및 목표 달성여부 평가에 널리 사용되고 있다. 현재 오염총량관리시행계획 이행평가에 적용되는 하천 수질평가는 부하지속곡선과 유량구간별 목표수질 초과율에 기반하나 이는 수질기준 초과 여부만을 판단하며 초과 수준을 반영하지 못해 수질평가결과에 왜곡을 초래할 수 있다. 따라서 본 연구에서는 기존 수질평가 방법의 한계를 보완하기 위해, 다수질기준 부하지속곡선, 수질등급비율 그리고 ‘좋은물’ 변화율을 활용한 새로운 수질평가 프레임워크를 제안하였다. 한강 청미천 유역을 대상으로, 개발한 프레임워크를 이용한 수질평가를 실시하여 다수질기준 부하지속곡선의 실제 수질평가에의 적용가능성을 검토하였다. 그 결과, 다수질기준 부하지속곡선을 통해 관측부하량의 수질등급 분포와 오염정도를 직관적으로 확인할 수 있었다. 또한, 수질등급비율을 통해 특정 수질기준을 초과하는 수질등급비율의 지속 발생 여부와 하천 수질 변화추세를 파악할 수 있고, 지점 간 수질 차이를 고려하여 하천 수질 특성을 파악할 수 있었다. 나아가, 개선된 프레임워크를 적용하여 다양한 유량구간 구분에 따라 하천 수질을 평가한 결과, 비점오염원 분석에 유량구간 설정 방식에 따른 ‘좋은물’ 비율 차이는 미미한 것으로 나타났다. 본 연구는 다수질기준 부하지속곡선이 기존 부하지속곡선보다 하천수질 상태에 대한 보다 다양하고 유용한 정보를 제공할 수 있음을 보여주었고, 이는 다수질기준 부하지속곡선이 하천 수질평가와 정책 의사결정 과정에서 유용한 도구로 사용될 수 있음을 시사한다.

키워드
목표수질
수질등급비율
수질관리
초과율
청미천
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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 : 58
  • No :12
  • Pages :1337-1349
  • Received Date : 2025-09-06
  • Revised Date : 2025-11-05
  • Accepted Date : 2025-11-11
  • DOI :https://doi.org/10.3741/JKWRA.2025.58.12.1337
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