scholarly journals SPATIAL EVALUATION OF THE WATER QUALITY FROM THE VELHAS RIVER CHANNEL, IN THE STATE OF MINAS GERAIS

2018 ◽  
Vol 15 (30) ◽  
pp. 75-86
Author(s):  
C. C. PINTO ◽  
K. B. ALMEIDA ◽  
S. C. OLIVEIRA

This study presents an evaluation of the water quality variability of 19 monitoring stations located in the channel of the Velhas river, using multivariate statistical techniques - Cluster Analysis (CA) and Principal Component Analysis/Factor Analysis (PCA/FA). Sixteen physical-chemical parameters were evaluated between January 2009 and June 2016, totalizing 27,232 valid observations. The CA grouped the nineteen monitoring stations into three groups based on the pollution levels. The PCA/FA resulted in six latent factors for group 1, four for group 2 and five for group 3, accounting for 71.44%, 65.32% and 61.69% of the total variance in the respective water quality. The factors indicated that the parameters responsible for the variations in water quality are mainly related to the release of sanitary sewage and industrial effluents and also to agriculture and livestock activities. These results reflect different water quality conditions of the Velhas River in its extension but, in fact, it is verified a greater variability of the water in the Metropolitan Region of Belo Horizonte and its downstream, justified by the different loads of pollutants received in this region, mainly the releases of domestic sewage and industrial effluents.

2020 ◽  
Vol 20 (4) ◽  
pp. 1215-1228
Author(s):  
Sanja Obradović ◽  
Milana Pantelić ◽  
Vladimir Stojanović ◽  
Aleksandra Tešin ◽  
Dragan Dolinaj

Abstract ‘Bačko Podunavlje’ represents one of the largest and the best-preserved wetland areas of the upper Danube. Water quality is crucial for nature in protected areas and ecotourism. The paper is based on data for the period 1992–2016. Using multivariate statistical analysis, water quality was defined. One-factor analysis of variations is the starting point for the analysis of time variables (annual and monthly analysis). The principal component analysis (PCA) of the ten quality parameters is in the three factors that determine the greatest impact on the change in water quality. Results revealed the satisfactory ecological status of the Danube River in these sections (Bezdan and Bogojevo) and there is no threat that the biodiversity of this area is endangered by poor water quality, which fully justifies the possibilities for intensive development of ecotourism in the biosphere reserve. Suspended solids are the only parameter that exceeds the allowed limit values in a larger number of measurements, especially in the summer period of the year. Other analyzed water quality parameters range within the allowed limit values for the second class of surface water quality based on the Law on Waters (Republic of Serbia) and in accordance with the Water Quality Classification Criteria of ICPDR.


2016 ◽  
Vol 2 (4) ◽  
pp. 211
Author(s):  
Girdhari Lal Chaurasia ◽  
Mahesh Kumar Gupta ◽  
Praveen Kumar Tandon

Water is an essential resource for all the organisms, plants and animals including the human beings. It is the backbone for agricultural and industrial sectors and all the small business units. Increase in human population and economic activities have tremendously increased the demand for large-scale suppliers of fresh water for various competing end users.The quality evaluation of water is represented in terms of physical, chemical and Biological parameters. A particular problem in the case of water quality monitoring is the complexity associated with analyzing the large number of measured variables. The data sets contain rich information about the behavior of the water resources. Multivariate statistical approaches allow deriving hidden information from the data sets about the possible influences of the environment on water quality. Classification, modeling and interpretation of monitored data are the most important steps in the assessment of water quality. The application of different multivariate statistical techniques, such as cluster analysis (CA), principal component analysis (PCA) and factor analysis (FA) help to identify important components or factors accounting for most of the variances of a system. In the present study water samples were analyzed for various physicochemical analyses by different methods following the standards of APHA, BIS and WHO and were subjected to further statistical analysis viz. the cluster analysis to understand the similarity and differences among the various sampling stations.  Three clusters were found. Cluster 1 was marked with 3 sampling locations 1, 3 & 5; Cluster-2 was marked with sampling location-2 and cluster-3 was marked with sampling location-4. Principal component analysis/factor analysis is a pattern reorganization technique which is used to assess the correlation between the observations in terms of different factors which are not observable. Observations correlated either positively or negatively, are likely to be affected by the same factors while the observations which are not correlated are influenced by different factors. In our study three factors explained 99.827% of variances. F1 marked  51.619% of total variances, high positive strong loading with TSS, TS, Temp, TDS, phosphate and moderate with electrical conductivity with loading values of 0.986, 0.970, 0.792, 0.744, 0.695,  0.701, respectively. Factor 2 marked 27.236% of the total variance with moderate positive loading with total alkalinity & temp. with loading values 0.723 & 0.606 respectively. It also explained the moderate negative loading with conductivity, TDS, and chloride with loading values -0.698, -0.690, -0.582. Factor F 3 marked 20.972 % of the variances with positive loading with PH, chloride, and phosphate with strong loading of pH 0.872 and moderate positive loading with chloride and phosphate with loading values 0.721, and 0.569 respectively. 


Phytotaxa ◽  
2017 ◽  
Vol 302 (2) ◽  
pp. 122 ◽  
Author(s):  
ZHIKE ZHANG ◽  
GUIFEN LI ◽  
XIANGHUI YANG ◽  
SHUNQUAN LIN

A phenetic analysis was obtained using numerical taxonomy involving 27 accessories composed of species and varieties of Eriobotrya Lindl. and two related species, Photinia serrulata Lindl., and Rhapiolepis indica Lindl. Principal component analysis (PCA) was used to separate 53 morphological traits. Leaf morphology was essential for the classification of Eriobotrya. Clustering was consistent with traditional taxonomy. Eriobotrya was distinctly separate from its related genera, and when the similarity coefficient was 0.55, the Eriobotrya accessions could be divided into five groups as follows: Group 1: species with small leaf, included E. angustissima Hook. f., E. henryi Nakai, and E. seguinii Cardot ex Guillaumin; Group 2: Species with mid-size and large leaf included E. japonica Lindl., E. malipoensis K.C. Kuan, E. serrata J.E. Vidal, and E. stipularis Craib; Group 3: Species with large leaf distributed in tropical and south subtropical areas, E. elliptica Lindl., E. ellliptica f. peniolata Hook., and E. elliptica var. petelottii Vidal; Group 4: Species with tomentose leaves included E. prinoides Rehder & E.H. Wilson,  E.× daduheensis H.Z. Zhang ex W.B. Liao, Q. Fan & M.Y. Ding, E. prinoides var. laotica Vidal, E. salwinensis Hand.-Mass., and E. tengyuehensis W.W. Smith; Group 5: All the remaining species including E. bengalensis Hook. f. bengalensis, E. bengalensis (Roxb.) Hook. f. forma angustifolia (Card.) Vidal E. cavaleriei Rehder, E deflexa Nakai, E. deflexa f. buisanensis Nakia, E. deflexa f. koshunensis, E. fragrans Champ. ex Benth., E. kwangsiensis, E. obovata, and E. potlanei Vidal. Our results were in total agreement with the traditional taxonomy of Eriobotrya classification and provide a foundation for the classification and genetic improvement of loquat germplasm.


HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 1991-1995 ◽  
Author(s):  
Omar Franco-Mora ◽  
Edgar Jesús Morales-Rosales ◽  
Andrés González-Huerta ◽  
Juan Guillermo Cruz-Castillo

Thirty-four accessions of wild grapevines, native to three regions of the state of Puebla, Mexico, that is Teziutlán, Tehuacán, and Atlixco, were vegetatively characterized with 32 suggested IPGRI, UPOV, and OIV descriptors related to young shoot (YS), mature shoot (MS), young leaf (YL), mature leaf (ML), and woody shoot (WS). Excepting profile and absence of sinus teeth in ML, the remaining parameters showed variation among the accessions. After the performance of a correlation analysis among the 32 characters, only those closely correlated were used; that is, for MS: color of dorsal side of node, density of prostrate trichomes of internode; for YL: density of prostrate trichomes between veins and density of erect trichomes on main veins; and for ML: general shape of petiole sinus and the density of erect trichomes on veins in mature leaves. With those six characters, six principal components explained the total variability observed. The most closely related descriptors for principal Component 1 were the ML general shape of petiole sinus (−0.735) and the YL density of erect trichomes on main veins (0.659), whereas for principal Component 2, the MS color of the dorsal side of the node (0.677) and the density of erect trichomes in ML (0.596) were the most highly related. A cluster analysis identified four groups with a euclidean distance of 18; except for plant 183, the other six included in Group 1 were native to the regions Atlixco and Tehuacán; Group 2 was formed by plants native to the three regions, whereas Group 3 was formed by plants native to Teziutlán and Atlixco; Group 4 was formed only by Plant 36, native to Atlixco. These results show that variation among accessions occurs within and among the three states of the Puebla region.


2021 ◽  
pp. 56-77
Author(s):  
Thyego Silva ◽  
Mariucha Lima ◽  
Teresa Leitão ◽  
Tiago Martins ◽  
Mateus Albuquerque

A hydrochemical study was conducted on the Quaternary Aquifer, in Recife, Brazil. Groundwater samples were collected in March–April 2015, at the beginning of the rainy season. Conventional graphics, ionic ratios, saturation indices, GIS mapping, and geostatistical and multivariate statistical analyses were used to water quality assessment and to characterize the main hydrochemical processes controlling groundwater’s chemistry. Q-mode hierarchical cluster analysis separated the samples into three clusters and five sub-clusters according to their hydrochemical similarities and facies. Principal Component Analysis (PCA) was employed to the studied groundwater samples where a three-factor model explains 80% of the total variation within the dataset. The PCA results revealed the influence of seawater intrusion, water-rock interaction, and nitrate contamination. The physico-chemical parameters of ~30% groundwaters exceed the World Health Organization (WHO) guidelines for drinking water quality. Nitrate was found at a concentration >10 mg NO3−/L in ~21% of the wells and exceeded WHO reference values in one. The integrated approach indicates the occurrence of the main major hydrogeochemical processes occurring in the shallow marine to alluvial aquifer as follow: 1) progressive freshening of remaining paleo-seawater accompanying cation exchange on fine sediments, 2) water-rock interaction (i.e., dissolution of silicates), and 3) point and diffuse wastewater contamination, and sulfate dissolution. This study successfully highlights the use of classical geochemical methods, GIS techniques, and multivariate statistical analyses (hierarchical cluster and principal component analyses) as complementary tools to understand hydrogeochemical processes and their influence on groundwater quality status to management actions, which could be used in similar alluvial coastal aquifers.


2011 ◽  
Vol 71 (4) ◽  
pp. 949-959 ◽  
Author(s):  
SE. Salomoni ◽  
O. Rocha ◽  
G. Hermany ◽  
EA. Lobo

The Gravataí river situated in the metropolitan region of Porto Alegre has an area of approximately 2.020 km² and provides public water supply to about 500,000 inhabitants in 5 municipalities (latitude 29° 45'-30° 12' S; longitude 50° 27'-51° 12' W). The river basin has two regions with distinctive characteristics of occupation: the upper course shows intensive farming and the lower course presents urban and industrial uses. In this context, the aim of this study was to evaluate the water quality in the Gravataí River (RS, Brazil) by using physical, chemical and microbiological variables, and the water quality biological indices (WQBI) formulated for southern Brazilian rivers based on epilithic diatom communities as indicators. For comparison purposes, a local WQBI, called the Gravataí WQBI, was also used where species were given new saprobic values (s) and indicative values (vi) according to their occurrence and abundance in the river, using multivariate analytical techniques. The biological samples were taken every three months at six stations along the Gravataí River between September 2000 and August 2002. The results of the physical and chemical analyses of the water indicated a pollution gradient down the river, from the headwaters to the mouth, detected mainly by considering a significant decrease in the concentration of dissolved oxygen and turbidity, as well as a significant increase in BOD5, total nitrogen, ortho-phosphate and thermotolerant coliforms. Comparing the results obtained, differences were found regarding the predominant pollution levels as higher in the Gravataí WQBI, although both corroborated a tendency for the contamination gradient to increase from the headwaters to the mouth. Given the local anthropic changes, it is of great importance to continue the study of diatom species tolerance to organic pollution and eutrophication in different lotic systems of the region.


1999 ◽  
Vol 59 (4) ◽  
pp. 553-561 ◽  
Author(s):  
M. M. G. S. M. MARQUES ◽  
F. A. R. BARBOSA ◽  
M. CALLISTO

Patterns of abundance and distribution of chironomid midges (Diptera, Chironomidae) in the middle Rio Doce basin were analysed. Human activities (mining, steel processing, and Eucalyptus spp. forestry) contribute to environmental degradation and low water quality in this watershed. Physical and chemical water traits (dissolved oxygen, pH, total alkalinity, electric conductivity, phosphorus and nitrogen concentrations) of 20 sampling points were used in a Principal Component Analysis (PCA) to establish the best and worst water quality. Sampling points recorded as the most polluted showed low genus richness of Chironomidae, less than five genera from the total 23, and dominance of the genus Chironomus, a bioindicator of environmental stress. Following Chironomus, the second most frequent and abundant genus was Cricotopus, whose distribution could not be related to pollution levels. The Tanypodinae sub-family showed certain sensitivity to low dissolved oxygen concentrations and high nutrients levels, and was not found at points of high pollution levels.


2019 ◽  
Vol 9 (7) ◽  
Author(s):  
M. Jahangiry Fard ◽  
H. Amanipoor ◽  
S. Battaleb-Looie ◽  
K. Ghanemi

Abstract Outcrop of Gachsaran evaporative formation in the lake of Gotvand-e-Olya Dam in SW IRAN has posed a major challenge in terms of water quality. In the present study, multivariate statistical analysis, ionic ratios, and Piper diagram were utilized to investigate the effect of formation dissolution on water quality. Sampling was performed two times with a time interval of 6 months. The result showed that the types of downstream samples are Cl–Na and Cl–Ca, which are affected by the dissolution of Gachsaran Formation and reverse ion exchange. Due to the transmission of the saline water to the depth and layering of reservoir, the water types in the upper levels of dam’s lake are (SO4–Ca and HCO3–Ca) and (Cl–Ca and SO4–Ca) upon the first and second sampling, respectively. In both times, the clustering of the EC, TDS, Na, and Cl parameters demonstrates the effect of halite dissolution on water quality in downstream and lake of the dam. At the first sampling, the SO4 and HCO3 parameters are in one cluster that shows increasing calcareous formation dissolution. At the second time, the grouping of the Ca and SO4 parameters shows the effect of gypsum and anhydrite dissolution on water quality. In both sampling times, the stations are grouped based on distance to the dam such that upstream stations are in one cluster. Results of principal component analysis show that data of the first-time sampling are summarized into two factors that show the effect of the formation dissolution and rainfall effect on water quality, respectively. At the second-time sampling, studied parameters are summarized in one factor. Local conditions of the studied area indicate the dominant effect of formation dissolution on water quality. The results of ionic ratios confirm the effect of geological formation on water quality in the lake and downstream of the dam. Due to the water layering, in terms of salinity in the dam’s lake, the rate and discharge of water outflow of the dam also affect the water quality in downstream.


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