长江口夏季低氧区形成及加剧的成因分析  

Study on Main Influencing Factors of Formation and Deterioration of Summer Hypoxia off the Yangtze River Estuary

作　　者：刘海霞[1] 李道季[1] 高磊[1] 王伟伟[1] 陈炜清[1] 

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200062

出　　处：《海洋科学进展》2012年第2期186-197,共12页Advances in Marine Science

基　　金：国家全球变化重大科学研究计划项目--我国典型海岸带系统对气候变化的响应机制及脆弱性评估研究(2010CB951203);上海市科委知识创新项目--长江河口生态系统对气候变化的响应机制及脆弱性评估研究(10JC1404400);华东师范大学河口海岸学国家重点实验室科研业务课题--长江河口锋面过程及其对过滤器效应的影响(2009KYYW03)

摘　　要：通过对比长江口及其邻近海域历史调查资料和目前的现场监测数据(1958-09—1959-09,2003-09,2005-07及2009-08),分析了长江口夏季低氧区的历史变化,探讨了低氧形成及其加剧的原因。结果表明:20世纪90年代之后长江口季节性低氧区出现扩大化、严重化趋势;低氧区的形成主要受控于物理过程和自然作用,包括长江冲淡水、沿岸流、上升流、台湾暖流及黑潮等各大流系及其与温度等理化因素相互作用下形成的水体层化、锋面过程、气旋式冷涡;低氧现象加剧原因复杂,影响因子有气候变化导致的海水温度上升,长江径流量、输沙量变化,长江流域降雨变化等,而富营养化的加剧对低氧加剧并非起主导作用。This paper analyzed the historical changes of summer hypoxia off the Yangtze River Estuary, and discussed the formation and aggravating reason of the hypoxia according to the survey data from Sep. 1958 to Sep. 1959, Sep. 2003, Jul. 2005 and Aug. 2009. The results showed that： since1990s, thehypoxia off the Yangtze River Estuary presented a deterioration trend in the hypoxia extent and DO value; the formation of hypoxia was influenced by physical and natural processes, mainly including the influence of some current systems, such as the Yangtze River diluted water, coastal current, upwelling current, Taiwan warm current and Kuroshio current, as well as other factors such as water stratification, frontal process and cyclonic cold vortex shaped by interaction of current with physical and chemical factors like temperature. The aggravating reasons of the hypoxia were complicated, the mainly influencing factors may include the rise in seawater temperature caused by changes of global climate, variation in the Yangtze River water discharge and sediment discharge, and precipitation strength in the middle and lower reaches of Yangtze River. However, the eutrophication did not play the leading role in the aggravation of hypoxia.

关 键 词：低氧区 长江口 溶解氧 海水温度变化 

分 类 号：P734[天文地球—海洋化学]