Multivariate analysis of the water quality of a set of Quebec lakes: finding watershed explicative factors of the acidification process

1991 ◽  
Vol 18 (4) ◽  
pp. 644-653
Author(s):  
M. Lachance ◽  
B. Bobée ◽  
G. de Marsily
Keyword(s):  
Water Quality ◽  
Multivariate Analysis ◽  
Spatial Variability ◽  
Correspondence Analysis ◽  
Multiple Correspondence Analysis ◽  
Hierarchical Classification ◽  
Water Quality Variables ◽  
Geographical Regions ◽  
Saguenay River

In this study, a new methodological approach is proposed to analyze the spatial variability of the water quality of a set of lakes. The Quebec region under study is located in the southeast part of the Canadian Shield between the Ottawa River and the Saguenay River. The proposed methodology is based on the combined use of correspondence analysis and hierarchical classification analysis. These methods provided the analyst with a geometric representation of the spatial variation of the physicochemical parameters of the water quality (pH, alkalinity, calcium + magnesium, sulfate) recognized as indicators of the acidification of aquatic ecosystems. Afterwards by imposing a contiguity constraint in hierarchical classification, the analysis led to the delimitation of five geographical regions that are similar with respect to the four variables related to the acidification process. Then the relations between the water quality variables and some biophysical variables are examined. The multiple correspondence analysis made it easier to identify the biophysical variables of the watershed that are explicative of the water quality variables. Amongst these explicative variables examined, we have identified that the sulfate concentration in the precipitation, the annual precipitation, the altitude of lakes, and the type of vegetation and geology are more or less explicative for the alkalinity, the pH, the Ca + Mg, and the sulfate. The results can be used to build a regression model for the prediction of some physicochemical variables from the knowledge of certain key variables describing the biophysical characteristics of the watersheds. Key words: spatial variability, multivariate analysis, acidification, water quality, explicative factors, lakes, Quebec.

scholarly journals Citizen Science Tools Reveal Changes in Estuarine Water Quality Following Demolition of Buildings

2021 ◽  
Vol 13 (9) ◽  
pp. 1683
Author(s):  
Nandini Menon ◽  
Grinson George ◽  
Rajamohananpillai Ranith ◽  
Velakandy Sajin ◽  
Shreya Murali ◽  
...  
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Citizen Science ◽  
Secchi Depth ◽  
Lake Water Quality ◽  
Demolition Waste ◽  
Water Colour ◽  
Water Quality Variables ◽  
The Impact

Turbidity and water colour are two easily measurable properties used to monitor pollution. Here, we highlight the utility of a low-cost device—3D printed, hand-held Mini Secchi disk (3DMSD) with Forel-Ule (FU) colour scale sticker on its outer casing—in combination with a mobile phone application (‘TurbAqua’) that was provided to laymen for assessing the water quality of a shallow lake region after demolition of four high-rise buildings on the shores of the lake. The demolition of the buildings in January 2020 on the banks of a tropical estuary—Vembanad Lake (a Ramsar site) in southern India—for violation of Indian Coastal Regulation Zone norms created public uproar, owing to the consequences of subsequent air and water pollution. Measurements of Secchi depth and water colour using the 3DMSD along with measurements of other important water quality variables such as temperature, salinity, pH, and dissolved oxygen (DO) using portable instruments were taken for a duration of five weeks after the demolition to assess the changes in water quality. Paired t-test analyses of variations in water quality variables between the second week of demolition and consecutive weeks up to the fifth week showed that there were significant increases in pH, dissolved oxygen, and Secchi depth over time, i.e., the impact of demolition waste on the Vembanad Lake water quality was found to be relatively short-lived, with water clarity, colour, and DO returning to levels typical of that period of year within 4–5 weeks. With increasing duration after demolition, there was a general decrease in the FU colour index to 17 at most stations, but it did not drop to 15 or below, i.e., towards green or blue colour indicating clearer waters, during the sampling period. There was no significant change in salinity from the second week to the fifth week after demolition, suggesting little influence of other factors (e.g., precipitation or changes in tidal currents) on the inferred impact of demolition waste. Comparison with pre-demolition conditions in the previous year (2019) showed that the relative changes in DO, Secchi depth, and pH were very high in 2020, clearly depicting the impact of demolition waste on the water quality of the lake. Match-ups of the turbidity of the water column immediately before and after the demolition using Sentinel 2 data were in good agreement with the in situ data collected. Our study highlights the power of citizen science tools in monitoring lakes and managing water resources and articulates how these activities provide support to Sustainable Development Goal (SDG) targets on Health (Goal 3), Water quality (Goal 6), and Life under the water (Goal 14).

scholarly journals Multivariate Analysis for Assessing Irrigation Water Quality: A Case Study of the Bahr Mouise Canal, Eastern Nile Delta

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2537 ◽  
Author(s):  
Mohamed K. Abdel-Fattah ◽  
Sameh Kotb Abd-Elmabod ◽  
Ali A. Aldosari ◽  
Ahmed S. Elrys ◽  
Elsayed Said Mohamed
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Multivariate Analysis ◽  
Sustainable Agriculture ◽  
Irrigation Water ◽  
Class Ii ◽  
Class I ◽  
Landsat 8 ◽  
Irrigation Water Quality

Water scarcity and suitable irrigation water management in arid regions represent tangible challenges for sustainable agriculture. The current study aimed to apply multivariate analysis and to develop a simplified water quality assessment using principal component analysis (PCA) and the agglomerative hierarchical clustering (AHC) technique to assess the water quality of the Bahr Mouise canal in El-Sharkia Governorate, Egypt. The proposed methods depended on the monitored water chemical composition (e.g., pH, water electrical conductivity (ECiw), Ca2+, Mg2+, Na+, K+, HCO3−, Cl−, and SO42−) during 2019. Based on the supervised classification of satellite images (Landsat 8 Operational Land Imager (OLI)), the distinguished land use/land cover types around the Bahr Mouise canal were agriculture, urban, and water bodies, while the dominating land use was agriculture. The water quality of the Bahr Mouise canal was classified into two classes based on the application of the irrigation water quality index (IWQI), while the water quality was classified into three classes using the PCA and AHC methods. Temporal variations in water quality were investigated, where the water qualities in winter, autumn, and spring (January, February, March, April, November, and December) were classified as class I (no restrictions) based on IWQI application, and the water salinity, sodicity, and/or alkalinity did not represent limiting factors for irrigation water quality. On the other hand, in the summer season (May, June, July, August, and October), the irrigation water was classified as class II (low restrictions); therefore, irrigation processes during summer may lead to an increase in the alkalinity hazard. The PCA classifications were compared with the IWQI results; the PCA classifications had similar assessment results during the year, except in September, while the water quality was assigned to class II using the PCA method and class I by applying the IWQI. Furthermore, the normalized difference vegetation index (NDVI) around the Bahr Mouise canal over eight months and climatic data assisted in explaining the fluctuations in water quality during 2019 as a result of changing the crop season and agriculture management. Assessments of water quality help to conserve soil, reduce degradation risk, and support decision makers in order to obtain sustainable agriculture, especially under water irrigation scarcity and the limited agricultural land in such an arid region.

Characterizing adaptations of serve indicators in top-level male volleyball among seasons

2020 ◽  
pp. 174795412097892
Author(s):  
Konstantinos Sotiropoulos ◽  
Sotirios Drikos ◽  
Sophia D Papadopoulou ◽  
Karolina Barzouka
Keyword(s):  
Correspondence Analysis ◽  
Olympic Games ◽  
Multiple Correspondence Analysis ◽  
Horizontal Axis ◽  
Special Focus ◽  
Linear Modelling ◽  
Chi Squared ◽  
Position Type ◽  
Log Linear

The purpose of this study was to analyse selected serve characteristics in top-level male volleyball, with a special focus on detecting adaptations of the serve skill among seasons. The indicators examined were type, position, direction and quality of serve. The sample consisted of 5482 serves from three final phases of different top-level tournaments (Olympic Games 2012, N = 1942, World League 2017, N = 1883, World Championship 2018, N = 1657). The interrelationships between variables were analyzed using chi-squared tests, log-linear modelling and multiple correspondence analysis. The results showed that the interaction of all serve indicators are statistically important, but the combination of the variables’ categories that were more responsible for association alternated across the seasons under study. A 3-way association term was revealed for season 2012 (type/position/direction) and 2018 (type/position/quality), while for season 2017 multiple 2-way interactions were found (type/position, type/direction, position/quality, direction/quality). The direction of the serve to the horizontal axis of the court was correlated to the quality of serve and consequently with the advantage of the serving team, while a more tactical perspective for serve skill is formed over periods in top level male volleyball.

Spatial variability in surface water quality of lakes and ex-mining ponds in Malacca, Malaysia: the geochemical influence

2020 ◽  
Vol 197 ◽  
pp. 319-327
Author(s):  
Isa Baba Koki ◽  
◽  
Kah Hin Low ◽  
Sharifuddin Md Zain ◽  
Hafizan Juahir ◽  
...  
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Spatial Variability ◽  
Surface Water Quality

Relationships between epipelic diatoms, aquatic macrophytes, and water quality in Akarçay Stream, Afyonkarahisar, Turkey

2012 ◽  
Vol 41 (1) ◽  
Author(s):  
Mustafa Kargıoğlu ◽  
Ahmet Serteser ◽  
Ersin Kıvrak ◽  
Yılmaz İçağa ◽  
Muhsin Konuk
Keyword(s):  
Water Quality ◽  
Correspondence Analysis ◽  
Diatom Assemblages ◽  
Diatom Indices ◽  
Macrophyte Community ◽  
Epipelic Diatoms ◽  
Central Turkey ◽  
Very High ◽  
Macrophyte Index

AbstractThe Akarçay is the most important stream in the Afyonkarahisar region in central Turkey. In this study, the relationships between epipelic diatoms, macrophytes, and the water quality of Akarçay Stream are presented. According to Canonical Correspondence Analysis (CCA), BOD5, COD, TDS, NH4-N, NO2-N, and PO4-P had the most significant effects on the diatom and macrophyte community structures of the stream. According to CCA and Correspondence Analysis (CA), dominant diatom species and macrophytes constituted two groups, eutrophic and polluted. While eutraphentic taxa were abundant among upstream diatoms, hypereutraphentic taxa were found downstream in the Akarçay. The diatom assemblages in the sites upstream were generally characterized by an abundance of β-mesosaprobous and α-mesosaprobous species, while the diatom assemblages downstream had a very high abundance of polisaprobous species. Eutrophic and hypertrophic macrophyte taxa (such as Lemna trisulca, Potamogeton nodosus, and Ranunculus sp.) covered a high percentage of the stream bottom. Both diatom indices and macrophyte indices with the exception of the Biological Macrophyte Index of Rivers (IBMR) were correlated with BOD5, COD, TDS, NH4-N, NO2-N, PO4-P, and EC. Physicochemical variables, diatom and macrophyte taxa and the results of diatom and macrophyte indices indicated that the Akarçay stream basin is eutrophic and organically polluted.

scholarly journals Non-hierarchical grouping: ‘K-mean’ and ‘K-medoid’ of plaques cisterns in the Pajeu region - PE

2020 ◽  
Vol 42 ◽  
pp. e44378
Author(s):  
Manoel Rivelino Gomes de Oliveira ◽  
David Venâncio da Cruz ◽  
Moacyr Cunha Filho
Keyword(s):  
Water Quality ◽  
Hierarchical Clustering ◽  
Optimal Partition ◽  
Cluster Validation ◽  
Clustering Method ◽  
Homogeneous Groups ◽  
Water Quality Variables ◽  
Hierarchical Grouping ◽  
Validation Criterion

This work uses non-hierarchical grouping methods to evaluate the quality of the groups formed by plate cisterns according to some water quality variables. These methods use the cluster validation criterion to determine the optimal partition, which provides the most homogeneous groups possible. The methods were tested on a sample of 100 cisterns located in the Pajeú region. However, the non-hierarchical clustering method of ‘K-medoid’ formed more homogeneous groups, and thus the best performance according to the Silhouette [s (i) = 0.64] statistics.

scholarly journals Correspondence of zooplankton assemblage and water quality in wetlands of Cachar, Assam, India: Implications for environmental management

2018 ◽  
Vol 18 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Sulata Kar ◽  
Papia Das ◽  
Uma Das ◽  
Maibam Bimola ◽  
Devashish Kar ◽  
...  
Keyword(s):  
Water Quality ◽  
Structural Variation ◽  
Zooplankton Community ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Geographical Regions ◽  
Increasing Trend ◽  
Freshwater Bodies ◽  
Freshwater Habitats

AbstractThe zooplankton assemblage of selected wetlands of Assam, India was assessed to deduce the structural variation in the context of water quality parameters. A two year study between 2012 and 2014 comprising of 530 samples from the five wetlands revealed the presence of 46 taxa, 26 Rotifera, 15 Cladocera, 4 Copepoda and 1 Ostracoda, in varying density. The rotifers dominated in terms of abundance (48 ind. cm−3) followed by the cladocerans (28 ind. cm−3) and the copepods (19 ind. cm−3) and showed significant (p <0.05) correlations with turbidity, alkalinity, hardness and phosphate contents of the water samples. The diversity and the richness of the zooplankton showed an increasing trend with the water temperature. Among the different taxa, Brachionus sp. was most abundant followed by Mesocyclops sp. while Beauchampiella sp. was represented in the least numbers. Application of the cluster analysis allowed the segregation of the different zooplankton based on the similarities of abundance in the samples. The water quality parameters like temperature, alkalinity, turbidity, magnesium and calcium were observed to be significant contributors in shaping the zooplankton community composition of the wetlands, revealed through the correlations and canonical correspondence analysis. As an extension, the information can be used in monitoring the quality of the freshwater habitats of the concerned and similar geographical regions, using the zooplankton as the major constituents. The variations in the abundance of cladoceran, copepod and rotifer zooplanktons can be used to understand the mechanisms that sustain the food webs of the aquatic community of the freshwater bodies.

Sign in / Sign up

Export Citation Format

Share Document