| 大辽河近入海河段水体溶解氧分布特征及低氧成因的初步分析 |
| 摘要点击 4367 全文点击 5727 投稿时间：2010-01-06 修订日期：2010-03-24 |
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| 中文关键词 溶解氧 低氧 大辽河 河口 |
| 英文关键词 dissolved oxygen hypoxia the Daliaohe River estuary |
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| 中文摘要 |
| 根据2009年春、夏季大辽河近入海河段的大面站和连续站观测，分析了水体溶解氧（dissolved oxygen， DO）的时空分布规律，并对近入海河段上游低氧区的成因进行了初步探讨.结果表明，水体溶解氧含量在空间分布上呈入海口高、河段上游低，表层高、底层低的趋势；时间分布上呈白天高、夜间低，春季高、夏季低的趋势.夏季溶解氧含量介于1.36～4.77 mg/L之间，平均为3.44 mg/L，其中河段下游的溶解氧含量平均为3.94 mg/L，上游距入海口约45 km处开始出现较大面积的低氧区，溶解氧含量平均为2.33 mg/L，最低1.36 mg/L.溶解氧与温度、盐度、叶绿素a、营养盐和高锰酸盐指数的相关性分析显示，溶解氧含量与营养盐和有机污染物的相关性最显著，由此推断低氧区形成的主要原因是径流营养盐的输入和有机污染物的排放，而夏季表层水温升高导致的水体垂直层化作用进一步加剧了底层溶解氧含量的降低. |
| 英文摘要 |
| Based on field surveys in the upper estuarine zone of the Daliaohe River in Spring and Summer of 2009, the spatial and temporal distributions of dissolved oxygen were analyzed and the mechanism of hypoxia were preliminarily discussed. The results indicated that DO concentrations were higher in the river mouth and lower in the upper reaches, higher in surface layers and lower in bottom concerning its spatial distribution. For its temporal distribution, DO concentrations were higher in daytime and lower at night, higher in Spring and lower in Summer. The DO concentrations in the upper estuarine zone of the Daliaohe River in Summer ranged between 1.36-4.77 mg/L with an average of 3.44 mg/L. The concentrations in the lower reaches were higher with an average of 3.94 mg/L. A large hypoxia area was recorded in Summer in the upper reaches of the estuary starting from about 45 km away from the river gate with an average DO concentration of 2.33 mg/L and a minimum of 1.36 mg/L. The correlation analysis showed that DO concentration was significantly correlated with nutrients and permanganate index. Excessive discharge of nutrients and organic pollutants were, therefore, main factors causing hypoxia, and water column stratification due to temperature rise in Summer in surface layers led to further reduction of DO in bottom layers of the water. |
