Marine hydrology

Comparison of environmental constituents in the Pearl River Estuary during summer of 1999 and 2009

  • YANG Wei ,
  • Luo-Lin ,
  • Gao-Yong-Li ,
  • Zu-Ting-Ting ,
  • Zhou-Wei ,
  • Wang-Dong-Xiao
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  • 1.  State Key Laboratory of Tropical  Oceanography  (South China Sea Institute of Oceanology, CAS), Guangzhou  510301, China;   
    2. Graduate University of CAS, Beijing 100049, China

Received date: 2010-04-08

  Revised date: 2010-08-03

  Online published: 2011-09-08

Abstract

By analyzing the temperature, salinity, dissolved oxygen (DO), chlorophyll, and river discharge data observed in the
summers of 1999 and 2009 in the Pearl River Estuary (PRE), we find that the spreading range of the freshwater plume in 1999
was larger than that in 2009 due to larger runoff from the Pearl River. The salinity profiles showed a strong stratification inside
the PRE in 1999, but a weak stratification in 2009, owing to the co-effect of the smaller river discharge and stronger winds
associated with the tropical storm “Nangka”, which makes the water column well mixed in the top 5 m. The DO distribution
patterns for the two years were similar near the surface, but were quite different at the bottom, especially in the western shal-
low area and outside the mouth of the PRE. In 1999, the DO concentration was less than 3 mg·L−1
 in the western shallow area and between 4−5 mg·L−1 outside the mouth of the PRE; but in 2009 it was greater than 5 mg·L−1
 in the western shallow area and less than 3mg·L−1 outside the mouth. Strong stratification in the PRE was the main reason for the low concentration of
bottom DO in the western shallow area in 1999. The intensified vertical mixing induced by “Nangka” facilitated the exchange
of DO between the surface and bottom waters, which prevented the formation of low concentration DO in this region in 2009;
however, the salinity stratification and consumption of oxygen by the phytoplankton blooms triggered by “Nangka” might be
the reasons for the low DO content in the bottom water outside the mouth of PRE.

Cite this article

YANG Wei , Luo-Lin , Gao-Yong-Li , Zu-Ting-Ting , Zhou-Wei , Wang-Dong-Xiao . Comparison of environmental constituents in the Pearl River Estuary during summer of 1999 and 2009[J]. Journal of Tropical Oceanography, 2011 , 30(4) : 16 -23 . DOI: 10.11978/j.issn.1009-5470.2011.04.016

References

[1] CHEN J C, HEINKE G W, ZHOU M J. The Pearl River Estuary Pollution Project (PREPP)[J]. Cont shelf Res, 2004, 24: 1739-1744.
[2] ZU T T, GAN J P. Process-oriented study of the river plume and circulation in the Pearl River Estuary: Response to the wind and tidal forcing[J]. Advances in Geosciences, 2007, 12: 225-242.
[3] DONG L X, SU J L, WONG L A, et al. Seasonal variation and dynamics of the Pearl River Plume[J]. Cont Shelf Res, 2004, 24: 1761-1777.
[4] SU J L. Overview of the South China Sea circulation and its influence on the coastal physical oceanography outside the Pearl River Estuary[J]. Cont Shelf Res, 2004, 24: 1745-1760.
[5] WONG L A, CHEN J C, DONG L X. A model study of the plume front of the Pearl River Estuary, China and adjacent coastal waters in the winter dry season[J]. Cont Shelf Res, 2004, 24: 1779-1795.
[6] OU S Y, ZHANG H, WANG D X,et al. Horizontal characteristics of buoyant plume off the Pearl River Estuary during summer[J]. J Coast Res, 2007, 50: 652-657.
[7] OU S Y, ZHANG H, WANG D X. Dynamics of the buoyant plume off the Pearl River Estuary in summer[J]. Environ Fluid Mech, 2009, 9: 471-492. 
[8] 庞海龙, 高会旺, 宋萍萍, 等. 夏季珠江冲淡水扩散路径分析[J]. 海洋预报, 2006, 23(3): 58-63.
[9] GAN J P, LI L, WANG D X, et al. Interaction of a river plume with coastal upwelling in the northeastern South China Sea[J]. Cont Shelf Res, 2009, 29: 728-740.
[10] CAI W J, DAI M H, WANG Y C. The biogeochemistry of inorganic carbon and nutrients in the Pearl River Estuary and the adjacent Northern South China Sea[J]. Cont Shelf Res, 2004, 24: 1301-1319.
[11] YIN K D, ZHANG J, QIAN P Y. Effect of wind events on phytoplankton blooms in the Pearl River Estuary during summer[J]. Cont Shelf Res, 2004, 24: 1909-1923.
[12] YIN K D, LIN Z F, KE Z Y. Temporal and spatial distribution of dissolved oxygen in the Pearl River Estuary and adjacent coastal waters[J]. Cont Shelf Res, 2004, 24: 1935-1948.
[13] 罗琳, 李适宇, 厉红梅. 夏季珠江口水域溶解氧的特征及影响因素[J]. 中山大学学报: 自然科学版, 2005, 44(6): 118-122.
[14] 罗琳, 李适宇, 王东晓. 珠江口夏季缺氧现象的模拟[J]. 水科学进展, 2008, 19(5): 729-736.
[15] LUO L, LI S Y, WANG D X. Hypoxia in the Pearl River Estuary, the South China Sea, in July 1999[J].Aquatic Ecosystem Health & Management, 2009,12(4): 418-428.
[16] 林卫强, 李适宇. 夏季伶仃洋COD、DO的垂向分布及其影响因素[J]. 中山大学学报: 自然科学版, 2002, 41(4): 82-86.
[17] 林洪瑛, 刘胜, 韩舞鹰. 珠江口底层海水季节性缺氧现象及其引发CTB的潜在威胁[J]. 湛江海洋大学学报, 2001, 21: 25-29.
[18] ZHAO H, TANG D L, WANG D X. Phytoplankton blooms near the Pearl River Estuary induced by Typhoon Nuri[J]. J Geophys Res, 2009, 114, C12027, doi:10.1029/ 2009JC005384.
[19] ZHAO H, TANG D L, WANG Y Q. Comparison of phytoplankton blooms triggered by two typhoons with different intensities and translation speeds in the South China Sea[J]. Mar Ecol Prog Ser, 2008, 365: 57-65.
[20] 姚章民, 王永勇, 李爱鸣. 珠江三角洲主要河道水量分配比变化初步分析[EB/OL]. [2008-10-31]. http://www. pearlwater.gov.cn/zjls/ t20071107_22029.htm.

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