Water Quality in Representative Tuojiang River Network in Southwest China

Wenqiang Zhang,Baoqing Shan,Yu Zhao,Huiming Cao,Xin Jin

doi:10.3390/w10070864

Wenqiang Zhang, Baoqing Shan + Show 3 more

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https://doi.org/10.3390/w10070864

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Abstract

To control pollutants in rivers, we need to have an understanding of the spatial and temporal variations on water quality in complex river networks. In this study, 153 sampling sties were located in Chengdu segment of Tuojiang River in 2017, 23 monitoring stations in Tuojiang River in the Chengdu segment from 2011 to 2016 were also collected. According to the data from the monitoring station, the concentrations of total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH4+), and chemical oxygen demand (CODcr) concentrations were exceeded the water quality targets at 22, 14, 10, and 3 of the 23 monitoring stations, respectively. The regression analysis showed the NH3, TN and TP was increased from 2011 to 2016 (R2NH4+ = 0.30, p < 0.05; R2TN = 0.88, p < 0.05; R2TP = 0.30, p < 0.05), which indicated water quality was deteriorated from 2011 to 2016. In the 153 sample sites, the NH4+, CODcr, TP and TN concentrations exceeded the class III water quality threshold at 23%, 23%, 26%, and 99% of the total sampling sites, respectively. Correlation analysis showed that the main sources of NH4+, CODcr, TN, and TP (R2NH4+-CODcr = 0.572; R2NH4+-TN = 0.543; R2NH4+-TP = 0.537, p < 0.01) were municipal domestic sewage. The main pollutants in Tuojiang river network were TN and TP, high P and N concentrations probably contribute to the deterioration of surface water quality at some sampling sites (R2TPs-TP = 0.183 and R2TNs-NH4+ = 0.472, p < 0.01). TP, TN, TP in the sediments (TPs), and TN in the sediments (TNs) have accumulated in the river system because the river morphology has been changed by, for example, the damage of riparian zones and the construction of water conservation structures. The results from this study will support initiatives to improve the overall water quality and function of the river ecosystem.

Highlights

The Yangtze River, the largest river in China, is considered to be one of the mother rivers in China.It has played a vital role in China’s economic and social development, which is home to approximately39% of China’s population and accounts for nearly 45% of its gross domestic product
All the tributaries and canals feed into the Tuojiang River, which flows into the Yangtze River
Analysis of the data showed that concentrations of total nitrogen (TN) and NH4 + decreased from 2011 to 2016 at the GKTQ, LWCX, QJDQ, and HY monitoring stations, while total phosphorus (TP) concentrations increased over the same period at the 201 Yiyuan (201YY), SHM, WFMY, HY, AMQ, XS, and LJS monitoring stations

Summary

Introduction

The Yangtze River, the largest river in China, is considered to be one of the mother rivers in China.It has played a vital role in China’s economic and social development, which is home to approximately39% of China’s population and accounts for nearly 45% of its gross domestic product. The Yangtze River, the largest river in China, is considered to be one of the mother rivers in China. It has played a vital role in China’s economic and social development, which is home to approximately. 39% of China’s population and accounts for nearly 45% of its gross domestic product. The Yangtze River comprises numerous tributaries, such as the Hanjiang, Minjiang, Jialingjiang, and Wujiang Rivers [3]. Most of cities are situated along either the main channel or its tributaries of the Yangtze. While the population has increased and cities have expanded, municipal water treatment facilities have not improved so large volumes of untreated wastewater discharge directly into the Yangtze’s main channel and its tributaries.

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