| 摘要: |
| 为解析东江南支流低氧现象的成因，并为水环境治理提供科学依据，本研究于2019年春夏季对该河流的主要断面进行了水质监测。监测结果显示，东江南支流的溶解氧（DO）水平从中游的道滘镇的6.89mg/L降至出海口处的4.08mg/L。DO与影响因子相关性分析显示，DO与水温呈显著负相关，与盐度正相关，而与氨氮和总磷等营养物质呈显著负相关。这些营养物质的增加与DO降低在空间上呈显著重叠，特别是在夏季。研究结果表明，东江南支流低氧现象受物理、化学和生物因素的共同影响，其中温度升高和营养物质含量增加导致中下游水体的氧气消耗加快，河道汇流处的断面缩窄和下游水体的透光性差导致DO补给不足，从而导致下游沙田泗盛断面经常性出现氧亏（低氧）现象。 |
| 关键词: 东江 溶解氧 时空动态 低氧 成因 |
| DOI： |
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| 基金项目:2023 年省科技创新战略专项资金科研项目gdsky2023-03、广东省自然科学(2021A1515012077) |
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| Temporal and Spatial Dynamics of Dissolved Oxygen and Analysis of Hypoxia Causes in Typical Sections of the Dongjiang Estuary |
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HUANG Guangling,huang bensheng,liuda,qiujing,huang guoru
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South China Unirersity of Technology, School of cinil engineering and transportation
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| Abstract: |
| In order to analyze the causes of the hypoxic phenomenon in the southern tributary of the Dongjiang River and provide a scientific basis for water environmental management, this study monitored the water quality of the main river sections during the spring and summer seasons of 2019. Monitoring results showed that the dissolved oxygen level in the southern tributary of the Dongjiang River dropped from 6.89mg/L in the middle reaches at Daojiao Town to 4.08mg/L at the estuary. Correlation analysis indicated that dissolved oxygen was significantly negatively correlated with water temperature and positively correlated with salinity, while exhibiting a significant negative correlation with nutrients such as ammonium nitrogen and total phosphorus. The spatial increase of these nutrients overlapped significantly with the reduction of dissolved oxygen, especially noticeable during the summer. The main cause of the hypoxic phenomenon in the southern tributary of the Dongjiang River was the combined influence of physical, chemical, and biological factors. The increase in water temperature and nutrient content accelerated oxygen consumption in the middle and lower reaches of the water body, while the narrowing of the river channel at confluences and poor light penetration in downstream waters led to insufficient replenishment of dissolved oxygen, consequently causing frequent hypoxic conditions at the lower reaches Shatian Sisheng section. |
| Key words: Dongjiang Dissolved Oxygen Temporal and Spatial Dynamics Hypoxia Causes |
