AccScience Publishing / AJWEP / Online First / DOI: 10.36922/AJWEP026170111
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ORIGINAL RESEARCH ARTICLE

Trend analysis of water quality variation in the estuarine reach of the Xiaojiang River, a tributary of the Three Gorges Reservoir Area

Xinyu Zuo1,2* ,  Yafeng Zou1 ,  Shuai Cheng2 ,  Bin Yan1 ,  Yunqiu Jiang2 ,  Zhongfu Xiong2 ,  Feng Lan2
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1 Chongqing Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir, Three Gorges Reservoir Area Environment and Ecology of Chongqing Observation and Research Station, College of Environmental and Chemical Engineering, Chongqing Sanxia University of Science and Technology, Chongqing, China
2 Upper Changjiang River Bureau of Hydrological and Water Resources Survey, Bureau of Hydrology, Changjiang Water Resources Commission, Chongqing, China
AJWEP, 026170111 https://doi.org/10.36922/AJWEP026170111
Received: 22 April 2026 | Revised: 13 May 2026 | Accepted: 13 May 2026 | Published online: 4 June 2026
(This article belongs to the Special Issue Frontiers in Sustainable Development of Ecology and Environment)
© 2026 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
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Abstract

Based on measured water quality data from 2010 to 2025, the water quality of the estuarine reach of the Xiaojiang River, a tributary of the Three Gorges Reservoir Area, was analyzed using the comprehensive water quality index method. Pearson correlation analysis and principal component analysis were further employed to reveal the major sources of pollution in the Xiaojiang River. The results showed that the water quality in the Xiaojiang estuary from 2010 to 2025 was mainly Class I. Significant seasonal variation was observed within each year, with more severe pollution in summer. Biochemical oxygen demand over five days, total nitrogen, total phosphorus, permanganate index, and fecal coliform were identified as the main pollution indicators. Principal component analysis showed that the estuarine reach of the Xiaojiang River was mainly affected by organic pollution, eutrophication, and fecal contamination. In response to these pollution problems, source control should be strengthened, and the discharge of major pollutants should be reduced to improve water quality. This study can provide a reference for water environment management in the tributaries of the reservoir area.

Graphical abstract
Keywords
Water quality assessment
Comprehensive water quality identification index
Principal component analysis
Pollution source apportionment
Funding
This study was funded by the Chongqing Municipal Special Program for Technological Innovation and Application Development (CSTB2025TIAD-QQZDQXXCZXBFFX0002).
Conflict of interest
The authors declare they have no competing interests.
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Asian Journal of Water, Environment and Pollution, Electronic ISSN: 1875-8568 Print ISSN: 0972-9860, Published by AccScience Publishing
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