Spatial and temporal variability of surface water pollution in the Mekong Delta, Vietnam

Wilbers, Gert-Jan; Becker, M.; Nga, La Thi; Sebesvári, Zita; Renaud, Fabrice G.

doi:10.1016/j.scitotenv.2014.03.049

Cited by 137 publications

(100 citation statements)

References 26 publications

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“…Although anthropogenic impacts are generally considered the main determinants of lake pollution, some climatic and geographical factors that reflect the capacity of the lake to buffer nutrient inputs could also play significant roles in explaining variation in water quality. For Honghu Lake, the results of the PCA indicated that F3 (12.68%) in the dry season, F2 (17.39%) and F3 (15.76%) in the wet season, and F2 (19.60%) in the normal season were all correlated with pH, DO and transparency (Table 2), which might be mainly influenced by climatic and geographical factors [38]. Transparency was lowest (between 0.5 m and 1 m) in the area connecting to the Yangtze River, which might be caused by the sediment being stirred up by waves during the frequent water exchange in the lake.…”

Section: Preliminary Identification Of Influencing Factors Of Water Qmentioning

confidence: 98%

Exploring the Spatial-Seasonal Dynamics of Water Quality, Submerged Aquatic Plants and Their Influencing Factors in Different Areas of a Lake

Wang

et al. 2017

Water

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Abstract:The degradation of water quality in lakes and its negative effects on freshwater ecosystems have become a serious problem worldwide. Exploring the dynamics in the associated factors is essential for water pollution management and control. GIS interpolation, principal component analysis (PCA) and multivariate statistical techniques were used to identify the main pollution sources in different areas of Honghu Lake. The results indicate that the spatial distribution of the concentrations of total nitrogen (TN), total phosphate (TP), ammonia nitrogen (NH 4 + -N), and permanganate index (COD Mn ) have similar characteristics and that their values gradually increased from south to north during the three seasons in Honghu Lake. The major influencing factors of water quality varied across the different areas and seasons. The relatively high concentrations of TN and TP, which might limit the growth of submerged aquatic plants, were mainly caused by anthropogenic factors. Our work suggests that spatial analyses combined with PCA are useful for investigating the factors that influence water quality and submerged aquatic plant biomass in different areas of a lake. These findings provide sound information for the future water quality management of the lake or even the entire lake basin.Keywords: lake water quality; spatial and seasonal variations; influencing factors; biomass of submerged aquatic plant; different areas of Honghu Lake

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Section: Preliminary Identification Of Influencing Factors Of Water Qmentioning

confidence: 98%

Exploring the Spatial-Seasonal Dynamics of Water Quality, Submerged Aquatic Plants and Their Influencing Factors in Different Areas of a Lake

Wang

et al. 2017

Water

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“…The method also can be extended to PCA has become a frequently used tool of identifying the KEIs in environmental applications due to its advantage of effective dimensionality reduction with minimal information loss. Many researchers had performed PCA to reduce the dimensionality of environmental variables to identify the key elements [17,[22][23][24], locate the critical controllers in determining the local aquatic structure [15,16,[49][50][51], as well as reveal the KEIs responsible for water quality variations [18][19][20][21]25]. In the normal PCA algorithm, the Pearson's correlation was often used to measure the correlations of the environmental variables and construct the correlation coefficient matrix R for the subsequent factor analysis.…”

Section: Discussionmentioning

confidence: 99%

Modified Principal Component Analysis for Identifying Key Environmental Indicators and Application to a Large-Scale Tidal Flat Reclamation

Chu

Liu

She

et al. 2018

Water

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Identification of the key environmental indicators (KEIs) from a large number of environmental variables is important for environmental management in tidal flat reclamation areas. In this study, a modified principal component analysis approach (MPCA) has been developed for determining the KEIs. The MPCA accounts for the two important attributes of the environmental variables: pollution status and temporal variation, in addition to the commonly considered numerical divergence attribute. It also incorporates the distance correlation (dCor) to replace the Pearson's correlation to measure the nonlinear interrelationship between the variables. The proposed method was applied to the Tiaozini sand shoal, a large-scale tidal flat reclamation region in China. Five KEIs were identified as dissolved inorganic nitrogen, Cd, petroleum in the water column, Hg, and total organic carbon in the sediment. The identified KEIs were shown to respond well to the biodiversity of phytoplankton. This demonstrated that the identified KEIs adequately represent the environmental condition in the coastal marine system. Therefore, the MPCA is a practicable method for extracting effective indicators that have key roles in the coastal and marine environment.

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“…O aumento da temperatura pode promover o aumento de sólidos dissolvidos e alguns íons dissociados, que podem elevar a condutividade (Wilbers et al, 2014). Também foi constatada correlação negativa (r= -0,975) significativa (p < 0,05) entre condutividade e pH, mas apenas no período seco.…”

Section: Parâmetros Limnológicosunclassified

Diagnóstico espacial e temporal de condições físico-químicas e microbiológicas do Córrego do Tanquinho, Ribeirão Preto, SP, Brasil

Grieco¹,

Fregonesi²,

Tonani³

et al. 2017

Rev. ambiente água

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RESUMOO objetivo do estudo foi avaliar as condições fisico-químicas e microbiológicas do Córrego do Tanquinho, localizado em área altamente urbanizada e industrializada no município de Ribeirão Preto, SP, Brasil, considerando variações espaciais e temporais. Os parâmetros limnológicos avaliados foram: pH, temperatura, turbidez, condutividade e oxigênio dissolvido (OD), com medições realizadas in situ. Os níveis de metais no sedimento e em água superficial foram analisados por Espectrofotometria de Absorção Atômica. Para a determinação dos Coliformes Totais e Escherichia coli foi empregada a técnica dos Tubos Múltiplos com utilização de substrato cromogênico. Os parâmetros OD, E. coli e a concentração dos metais Cu e Mn na água encontram-se em desacordo com a legislação. Os metais encontrados em maior concentração no sedimento foram Mn, Cr e Zn. A avaliação microbiológica evidenciou o despejo de esgoto doméstico no córrego e as concentrações de metais indicam a possível ocorrência de efluentes industriais, podendo gerar graves problemas de saúde pública. O diagnóstico espacial indicou os locais de amostragem com as piores condições microbiológicas e altas concentrações de metais, enquanto que a influência temporal foi observada no pH, Mn e Cr em água superficial, e Mn, Cr e Pb nos sedimentos. Os resultados mostraram que o Córrego do Tanquinho é um corpo hídrico impactado. Recomenda-se a realização de outros estudos que possam esclarecer melhor a origem das cargas poluidoras, além da conscientização da população e da adoção de medidas que possibilitem a recuperação e proteção desse corpo hídrico.Palavras-chave: água superficial, E. coli, metais, parâmetros limnológicos, sedimento.

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Spatial and temporal variability of surface water pollution in the Mekong Delta, Vietnam

Cited by 137 publications

References 26 publications

Exploring the Spatial-Seasonal Dynamics of Water Quality, Submerged Aquatic Plants and Their Influencing Factors in Different Areas of a Lake

Exploring the Spatial-Seasonal Dynamics of Water Quality, Submerged Aquatic Plants and Their Influencing Factors in Different Areas of a Lake

Modified Principal Component Analysis for Identifying Key Environmental Indicators and Application to a Large-Scale Tidal Flat Reclamation

Diagnóstico espacial e temporal de condições físico-químicas e microbiológicas do Córrego do Tanquinho, Ribeirão Preto, SP, Brasil

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