夏季伶仃洋COD、DO的垂向分布及其影响因素

Vertical Distribution of COD and DO and Its Affecting Factors in the Pearl River Estuary in Summer

1999年夏季对珠江口伶仃洋的COD、DO、盐度、温度等项目进行大规模的调研 ,结果表明 :在伶仃洋咸淡水交界海域 ,COD、DO垂向层化现象明显 ,根据其层次结构可分为上中高下低型、上高中下低型、上下高中低型。受淡水径流、咸水入侵和太阳辐射的影响 ,伶仃洋夏季存在稳定的温密跃层 ,水体出现层化。层型水体是影响COD、DO垂向分布最主要的因素 ,底泥和再悬浮有机物的降解耗氧是导致底层水体DO降低的主要原因。

The distribution of COD, DO, salinity and water temperature in the Pearl River Estuary were surveyed in the summer of 1999. The results indicated that the vertical concentrations of COD and DO has sharp stratification profiles in the mixing region of salt and fresh water. According to the vertical distribution characters, the hiberarchy of COD and DO could be divided into three types.Freshwater inflow, saline intrusion and solar radiation are main factors causing, the steady pycnocline and epilimnion in the Estuary. The stratificationof water body results in COD and DO stratification. The hypoxia in the bottom could be mainly caused by the degradation of organic matter resuspending from the bed mud.