Principal component analysis in the evaluation of environmental data

Zitko, V.

doi:10.1016/0025-326x(94)90329-8

Cited by 104 publications

(54 citation statements)

References 9 publications

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“…Principal components analysis (PCA) is a useful tool in the examination of multivariate data (Zitko 1994), and it is a special case of factor analysis which transforms the original set of intercorrelated variables into a set of uncorrelated variables that are linear combinations of the original variables. The first principal component is the linear combination of the variables that accounts for a maximum of the total variability of the data set.…”

Section: Evaluation Methodsmentioning

confidence: 99%

Assessment of dissolved heavy metal in the Yangtze River estuary and its adjacent sea, China

Wang

et al. 2009

Environ Monit Assess

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The purpose of this paper is to determine the concentrations of dissolved heavy metals namely mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu) and to investigate the relationships between nutrients (nitrate-nitrogen and phosphate) and dissolved heavy metals. For this purpose, the concentrations of dissolved heavy metals were measured through 51 voyages form 1984 to 2006 in the Yangtze river estuary and its adjacent sea. Results analysis showed that dissolved heavy metals were not the main pollutants in the Yangtze river estuary, and the main source of heavy metal contamination was industrial wastewater from terrestrial pollution during the past 20 years. Heavy metal values showed significant abundance in the south branch of the Yangtze River estuary and Hangzhou Bay. In addition, Pb showed negative correlation with nutrients, while the positive correlations between Hg, Cd, and nutrients were shown. The obtained molar ratios, DeltaCd/DeltaN = 1.68 x 10(-5) and DeltaCd/DeltaP = 1.66 x 10(-4), are close to those in plankton, showing the biogeochemical behavior and process of dissolved cadmium.

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Section: Evaluation Methodsmentioning

confidence: 99%

Assessment of dissolved heavy metal in the Yangtze River estuary and its adjacent sea, China

Wang

et al. 2009

Environ Monit Assess

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“…A principal component analysis (PCA) was applied to the data set of 10 abiotic variables and 4 biological variables for 8 sampling locations and over 15 yr (Zitko 1994). Normal distribution of the data was achieved using a log (1+x) transformation standardised by subtracting the mean and dividing by the standard deviation.…”

Section: Samplingmentioning

confidence: 99%

Long-term recovery of soft-bottom benthos following urban and industrial sewage treatment in the Nervión estuary (southern Bay of Biscay)

Borja¹,

Muxika²,

Franco³

2006

Mar. Ecol. Prog. Ser.

117

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The monitoring of marine benthic communities is based upon their ability to integrate long-term environmental conditions and it is considered an efficient, accurate and useful tool in the detection of pollution effects. However, long-term studies are scarce, and only few are devoted to recovery processes in estuaries following water treatment. In this contribution, the response of the Nervión estuary to sewerage processes is studied, using a long-term (1989 to 2003) data set of physico-chemical (dissolved oxygen, redox potential, organic matter, metals) and biological (density, richness and diversity in benthic communities) variables. The AMBI (AZTI's Marine Biotic Index) was designed to investigate the response of soft-bottom communities to natural and human-induced changes in European coastal water quality and is evaluated here. The first factor controlling the Nervión's benthic structure is found to be the bottom water oxygen saturation, hypoxia-and/or anoxia-produced azoic sediments. When water treatment commenced, benthic recolonisation was very rapid in terms of opportunistic species settlement. However, the community structure was highly disturbed, in terms of density, richness, diversity and AMBI values. AMBI and diversity values are highly correlated with oxygen saturation. When the water treatment continued, the high metal concentrations in the sediments inhibited recovery in some areas; they were a secondary factor in determining benthic structure. This contribution demonstrates that the AMBI is an efficient tool for detecting changes in benthic communities and in systems associated with sewerage schemes; it provides an indication of the proportions of opportunistic and sensitive species within a long-term series.

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“…If the number of components is practically the same, log transformation may be a useful alternative to column norm scaling when no error estimates are available (as in this case) and produce results that are easier to interpret (see later). In order to remove negative values from input data after log calculation and allow application of non-negativity constraints in ALS treatment, a constant value, usually equal to 1, has been recommended to be added to all the entries [36]. In this way, log values are always non-negative.…”

Section: Chemometric Methodsmentioning

confidence: 99%

Application of chemometric methods to the investigation of main microcontaminant sources of endocrine disruptors in coastal and harbour waters and sediments

Peré-Trepat

Petrović

Barceló

et al. 2004

Analytical and Bioanalytical Chemistry

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Identification, resolution and distribution of main microcontaminant sources of endocrine disruptors in Spanish harbours, coastal waters and sediments are investigated using chemometric methods. We investigated eighteen different endocrine disruptor chemical compounds, including non-ionic surfactants, their degradation products and linear alkylbenzene sulfonates, found in a total number of 74 samples (35 water samples and 39 sediment samples) over a period of 16 months from March 1999 to July 2000, and in 32 different geographical sites along the Spanish Mediterranean Coast (e.g. Barcelona, Tarragona, Almeria Harbour, Malaga and the Bay of Cadiz). Main environmental contamination sources of these endocrine disruptor compounds were investigated and interpreted according to their chemical composition and according to their resolved geographical distribution profiles.

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Principal component analysis in the evaluation of environmental data

Cited by 104 publications

References 9 publications

Assessment of dissolved heavy metal in the Yangtze River estuary and its adjacent sea, China

Assessment of dissolved heavy metal in the Yangtze River estuary and its adjacent sea, China

Long-term recovery of soft-bottom benthos following urban and industrial sewage treatment in the Nervión estuary (southern Bay of Biscay)

Application of chemometric methods to the investigation of main microcontaminant sources of endocrine disruptors in coastal and harbour waters and sediments

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