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2025 Vol.58, Issue 2 Preview Page

Original research article

Evaluation of long-term water quality trends and CCME-WQI applicability in agricultural watersheds of Korea
So-Jin Yeob1
,
Goo Bok Jung2
,
Byung-Mo Lee3
,
Jaewon Jeong4
,
Min Gyeong Kim5
,
Juhee Yu6
,
Yungi Cho7
,
Na-Young Park8
,
So-Youn Lee9
,
Jong-Hee Shin10
,
Youngmin Jin11
,
Yoon Jeong Ko12
,
Soon-kun Choi1*
1Research Scientist, Climate Change Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea
2Senior Researcher, R&D Planning Division, Research Policy Bureau, RDA, Jeonju 54875, Korea
3Senior Researcher, Climate Change Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea
4Research Scientist, Gyeonggi-do Agricultural Research & Extension Services, Hwaseong 18388, Korea
5Research Scientist, Gangwon-do Agricultural Research & Extension Services, Chuncheon 25300, Korea
6Research Scientist, Chungcheongbuk-do Agricultural Research & Extension Services, Cheongju 28130, Korea
7Research Scientist, Chungcheongnam-do Agricultural Research & Extension Services, Yesan 32418, Korea
8Research Scientist, Jeollabuk-do Agricultural Research & Extension Services, Iksan 56469, Korea
9Research Scientist, Jeollanam-do Agricultural Research & Extension Services, Naju 58213, Korea
10Research Scientist, Gyeongsangbuk-do Agricultural Research & Extension Services, Daegu 41404, Korea
11Senior Researcher, Gyeongsangnam-do Agricultural Research & Extension Services, Jinju 52638, Korea
12Research Scientist, Jeju-do Agricultural Research & Extension Services, Seogwipo 63024, Korea
*Corresponding Author
31 May 2025. pp. 240-250
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Abstract

This study analyzed 10-year (2015 - 2024) trends in water quality parameters and the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) across five provinces in Korea. The CCME-WQI analysis indicated that Gangwon-do maintained Fair to Good ratings with high stability, while Gyeonggi-do generally fell within the Marginal range. Chungcheong-do showed persistently low water quality, mostly within the Poor range. Jeolla-do exhibited mostly Poor-level quality, and Gyeongsang-do showed moderate variability with Fair-level quality overall. The nationwide average CCME-WQI was approximately 55.7, indicating a marginal water quality level overall. The coefficient of variation (CV) for CCME-WQI was consistently lower than that of individual parameters, supporting its robustness and representativeness as an integrated indicator. Correlation analysis revealed strong positive relationships between farmland ratio and nutrient-related indicators (e.g., CODMn, T-P, SS), and significant negative correlations between CCME-WQI and these pollutants (e.g., SS: r = -0.96). Additionally, cumulative precipitation—particularly in July—showed stronger negative correlations with CCME-WQI (e.g., July: r = -0.80) than the farmland ratio (r = -0.69), suggesting that hydrological variability may exert a more immediate influence on water quality in agricultural watersheds than static land use patterns. These findings suggest that CCME-WQI is an effective tool for long-term water quality evaluation in agricultural watersheds influenced by non-point source pollution.

Pearson correlation matrix among CCME-WQI, key water quality parameters, farmland ratio, and cumulative precipitation across five provinces in Korea.
Keywords
Agricultural watershed
CCME-WQI
Farmland ratio
Non-point source Pollution
Precipitation
Water quality index
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Information
  • Publisher :Korean Society of Soil Science and Fertilizer
  • Publisher(Ko) :한국토양비료학회
  • Journal Title :Korean Journal of Soil Science and Fertilizer
  • Journal Title(Ko) :한국토양비료학회 학회지
  • Volume : 58
  • No :2
  • Pages :240-250
  • Received Date : 2025-05-07
  • Revised Date : 2025-05-28
  • Accepted Date : 2025-05-29
  • DOI :https://doi.org/10.7745/KJSSF.2025.58.2.240
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