Integration of multi-source data for water quality classification in the Pearl River estuary and its adjacent coastal waters of Hong Kong

2004 ◽  
Vol 24 (16) ◽  
pp. 1827-1843 ◽  
Author(s):  
Xiaoling Chen ◽  
Yok Shueng Li ◽  
Zhigang Liu ◽  
Kedong Yin ◽  
Zhilin Li ◽  
...  
Keyword(s):  
Water Quality ◽  
Hong Kong ◽  
Coastal Waters ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Pearl River ◽  
Quality Classification ◽  
Source Data ◽  
Water Quality Classification ◽  
The Pearl River

scholarly journals Influence of seasonal monsoons on net community production and CO<sub>2</sub> in subtropical Hong Kong coastal waters

2011 ◽  
Vol 8 (2) ◽  
pp. 289-300 ◽  
Author(s):  
X.-C. Yuan ◽  
K. Yin ◽  
W.-J. Cai ◽  
A. Y. Ho ◽  
J. Xu ◽  
...  
Keyword(s):  
Hong Kong ◽  
Coastal Waters ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Pearl River ◽  
Wet Season ◽  
Net Community Production ◽  
The Pearl River ◽  
Hong Kong Coastal Waters ◽  
Community Production

Abstract. Data from seven cruises in three different environments including the Pearl River estuary, sewage discharge outfall, and eastern coastal/shelf waters were used to examine the seasonal variations in net community production (NCP) and the biologically active gases O2 and CO2. In the winter dry season, when monsoon-induced downwelling was dominant, NCP was negative (−84 ± 50 mmol C m−2 d−1) in all three regions. The negative NCP corresponded to O2 influxes of 100 ± 50 mmol O2 m−2 d−1 and CO2 effluxes of 24 ± 10 mmol C m−2 d−1. In the summer wet season, when upwelling brought the deep oceanic waters to the coast due to the southwest monsoonal winds, there was a 2 to 15-fold increase in integrated primary production (IPP) compared to winter. The increase in IPP was likely due to the favorable conditions such as stratification and the nutrient inputs from upwelled waters and the Pearl River estuary. NCP in the mixed layer reached up to 110 ± 48 mmol C m−2 d−1 in the wet season. However, accompanying the high positive NCP, we observed an O2 influx of 100 ± 60 mmol O2 m−2 d−1 and CO2 efflux of 21 ± 15 mmol C m−2 d−1. The contradictory observation of positive NCP and CO2 release and O2 uptake in the mixed layer could be explained by the influence of the southwest monsoon-induced upwelling along with the influence of the Pearl River, as the upwelling brought cold, low dissolved oxygen (DO, 160 ± 30 μM) and high dissolved inorganic carbon (DIC, 1960 ± 100 μatm) water to the surface in the wet season. Hence, the subtropical Hong Kong coastal waters are generally a CO2 source due to the monsoonal influence during both the dry-heterotrophic and wet-autotrophic seasons.

scholarly journals Influence of seasonal monsoons on net primary production and CO<sub>2</sub> in subtropical Hong Kong coastal waters

2010 ◽  
Vol 7 (4) ◽  
pp. 5621-5647
Author(s):  
X. C. Yuan ◽  
K. D. Yin ◽  
W.-J. Cai ◽  
A. Y. T. Ho ◽  
J. Xu ◽  
...  
Keyword(s):  
Hong Kong ◽  
Primary Production ◽  
Coastal Waters ◽  
Net Primary Production ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Pearl River ◽  
Wet Season ◽  
The Pearl River ◽  
Hong Kong Coastal Waters

Abstract. Data from seven cruises in three different environments including the Pearl River estuary, sewage discharge outfall and eastern coastal/shelf waters, were used to examine the seasonal variations in net primary production (NPP) and the biologically active gases O2 and CO2. In the winter dry season, when monsoon-induced downwelling was dominant, NPP was low (−60±50 mmol C m−2 d−1) in all three regions. The negative NPP corresponded to low O2 influxes (−100±50 mmol O2 m−2 d−1) and CO2 effluxes (24±10 mmol C m−2 d−1). In the summer wet season, when upwelling brought the bottom oceanic waters to the nearshore due to the southwest monsoonal wind, there was a 2 to 15-fold increase in integrated primary production (IPP) compared to winter. The increase in IPP was likely due to the favorable conditions such as stratification and the nutrient inputs from upwelled waters and the Pearl River estuary. NPP reached up to 240±100 mmol C m−2 d−1 in the wet season. However, accompanying the high positive NPP, we observed an influx of O2 (−100±60 mmol O2 m−2 d−1) and efflux of CO2 (25±15 mmol C m−2 d−1). The high positive NPP corresponding to a CO2 source and O2 sink could be explained by the influence of the southwest monsoon-induced upwelling, as the upwelling brought cold, low DO (160±30 μM) and high DIC (1960±100 μatm) water to the surface in the wet season. Hence, the subtropical Hong Kong coastal waters are generally a CO2 source due to the monsoonal influence in both the dry and wet seasons.

scholarly journals Reconstruction of the track and a simulation of the storm surge associated with the calamitous typhoon affecting the Pearl River Estuary in September 1874

2020 ◽  
Vol 16 (1) ◽  
pp. 51-64
Author(s):  
Hing Yim Mok ◽  
Wing Hong Lui ◽  
Dick Shum Lau ◽  
Wang Chun Woo
Keyword(s):  
Hong Kong ◽  
South China Sea ◽  
Storm Surge ◽  
South China ◽  
River Estuary ◽  
Pearl River Estuary ◽  
The South China Sea ◽  
Pearl River ◽  
The Pearl River Estuary ◽  
The Pearl River

Abstract. A typhoon struck the Pearl River Estuary in September 1874 (“Typhoon 1874”), causing extensive damage and claiming thousands of lives in the region during its passage. Like many other historical typhoons, the deadliest impact of the typhoon was its associated storm surge. In this paper, a possible track of the typhoon was reconstructed through an analysis of the historical qualitative and quantitative weather observations in the Philippines, the northern part of the South China Sea, Hong Kong, Macao, and Guangdong recorded in various historical documents. The magnitudes of the associated storm surges and storm tides in Hong Kong and Macao were also quantitatively estimated using storm surge model and analogue astronomical tides based on the reconstructed track. The results indicated that the typhoon could have crossed the Luzon Strait from the western North Pacific and moved across the northeastern part of the South China Sea to strike the Pearl River Estuary more or less as a super typhoon in the early morning on 23 September 1874. The typhoon passed about 60 km south–southwest of Hong Kong and made landfall in Macao, bringing maximum storm tides of around 4.9 m above the Hong Kong Chart Datum (http://www.geodetic.gov.hk/smo/gsi/Data/pdf/explanatorynotes.pdf, last access: 3 January 2020) at the Victoria Harbour in Hong Kong and around 5.4 m above the Macao Chart Datum (https://mosref.dscc.gov.mo/Help/ref/Macaucoord_2009_web_EN_v201702.pdf, last access: 3 January 2020) at Porto Interior (inner harbour) in Macao. Both the maximum storm tide (4.88 m above the Hong Kong Chart Datum) and maximum storm surge (2.83 m) brought by Typhoon 1874 at the Victoria Harbour estimated in this study are higher than all the existing records since the establishment of the Hong Kong Observatory in 1883, including the recent records set by super typhoon Mangkhut on 16 September 2018.

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