钦州湾水质自动监测的周年变化特征

Annual Variation Characteristics of Water Quality in Qinzhou Bay through Automatic Monitoring

【目的】研究钦州湾(茅尾海和钦州湾外湾)周年水质变化特征,探讨海湾水质经常性超标的原因。【方法】利用2012年在线自动监测数据,分析海域水温、盐度、pH值、溶解氧以及叶绿素的周年日、季变化。【结果】两个海区盐度、pH值、溶解氧均呈现一、四季度高,二、三季度低的特征,其中最高值出现在第一季度,最低值出现在第三季度。茅尾海叶绿素最高值出现在第三季度,而钦州湾外湾出现在第一季度。茅尾海和钦州湾外湾水质超标主要为pH值,超标天数分别为243d和42d。【结论】茅尾海和钦州湾外湾受河流影响明显,pH值经常性超标,主要原因是采用海水标准评价,建议尽快确定河口区范围、制定河口水质评价方法和标准,以对主要河口区水质进行合理评价和管理。

[Objective]The annual variation characteristics of water quality in Qinzhou bay(Mao-wei Sea and outside of Qinzhou bay)were studied,and the causes of usually exceeding standard of the water quality were investigated.[Methods]Diurnal and quarterly changes of water pH, temperature,salinity,dissolved oxygen and chlorophyll were analyzed,using the automatic monitoring data during 2012.[Results]The values of water pH,salinity and dissolved oxygen showed a high level in the first and fourth seasons,and low in the second and third seasons. Their maximum value occurred in the first season,and the minimum in the third season.The maximum value of chlorophyll of Maowei Sea occurred in the third season,while that of the outside of the Qinzhou bay revealed in the first season.The main factor of exceed standard was pH,of which 243 days exceed the standard in Maowei sea and 42 days in the outside of the Qinzhou bay.[Conclusion]The pH usually exceeds the standard,of which the main reason was that the sea water standard is used to evaluate the water quality of estuary,which significantly affected by surface water.It should be soon to determine the scope of the estuary and draft estuarine water quality assessment methods and standards that could reasonably evaluate and su-pervise the water quality of estuary.