Identification of priority polluted tributaries in the Yeongsan River basin using unit-area load duration curves

Jinyong Eom; Dongho Choi; Daehoon Kim; Jaeyoung Lee; Jina Beom; Yonguk Ryu; Jaewoon Jung

doi:10.3741/JKWRA.2025.58.S-4.1685

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2025 Vol.58, Issue 12S-4 Preview Page

Special Issue: 실험 실증 기반 하천관리

Identification of priority polluted tributaries in the Yeongsan River basin using unit-area load duration curves 단위면적당 부하지속곡선을 활용한 영산강수계 지류지천의 오염우심하천 선정

31 December 2025. pp. 1685-1698

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Abstract

This study developed Unit-Area Load Duration Curves (UALDCs) for 46 tributary streams across seven sub-basins of the Yeongsan River system to evaluate water quality compliance and identify priority polluted tributaries. Although water quality and streamflow were monitored monthly at the downstream end of each tributary, the limited data frequency posed challenges for constructing conventional Load Duration Curves (LDCs). To address this, the drainage-area ratio method was applied. Flow data for tributaries were estimated by applying the specific discharge (Q/A) derived from 8-day interval measurements of the main stream, assuming hydrological similarity within the sub-basins. Using the estimated flow duration curves and water quality standards, target UALDCs were derived. The study defined streams with a target water quality exceedance rate of 50% or higher as priority polluted tributaries. The analysis revealed that Biological Oxygen Demand (BOD) exceeded the target in 7 tributaries, while Total Phosphorus (T-P) exceeded the target in 21 tributaries. These results suggest that the UALDC approach is an effective tool for evaluating water quality compliance and prioritizing management strategies in data-scarce tributary watersheds.

Keywords

Tributary

Unit-area load duration curve

Water quality

Flow

Target water quality achievement rate

본 연구는 영산강수계 7개 중권역(영산강상류, 황룡강, 지석천, 죽산보, 고막원천, 영암천, 영산강하류)의 46개 지류지천을 대상으로 단위면적당 부하지속곡선(Unit-Area LDC)을 구축하고, 이를 통해 오염우심하천을 선정 및 평가하였다. 지류지천의 말단에서 월 1회 수행된 수질·유량 모니터링 자료만으로는 부하지속곡선을 작성하고 해석하는 데 한계가 있었다. 이를 보완하기 위해 본류와 지류 유역의 수문학적 유사성을 가정하고, 본류의 8일 간격 유량 자료를 활용한 유역면적비법(Drainage-Area Ratio Method)을 적용하여 지류의 장기 유량 자료를 생성하였다. 구축된 유량지속곡선과 중권역별 물환경목표기준을 결합하여 단위면적당 목표수질 부하지속곡선을 작성하였으며, 실측 부하량의 목표수질 초과율이 50% 이상인 경우를 오염우심하천으로 규정하였다. 분석 결과, BOD는 총 46개 지류지천 중 7개소가, T-P는 21개소가 오염우심하천으로 선정되었다. 해당 하천들의 실측 농도는 대부분의 유황 조건에서 목표기준을 상회하는 것으로 나타났다. 따라서 본 연구에서 제시한 단위면적당 부하지속곡선 기법은 측정 자료가 부족한 지류지천의 목표수질 달성도를 평가하고 수질 관리의 우선순위를 결정하는 데 효과적인 도구로 판단된다.

키워드

지류지천

단위면적당 부하지속곡선

수질

유량

목표수질 달성도

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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 :1685-1698
Received Date : 2025-11-17
Revised Date : 2025-11-27
Accepted Date : 2025-11-28
DOI :https://doi.org/10.3741/JKWRA.2025.58.S-4.1685

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

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