scholarly journals Development of a groundwater quality index: GWQI, for the aquifers of the state of Bahia, Brazil using multivariable analyses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Barbosa Filho ◽  
Iara Brandão de Oliveira

AbstractThis work elaborated a groundwater quality index—GWQI, for the aquifers of the state of Bahia, Brazil, using multivariable analyses. Data from 600 wells located in the four hydrogeological domains: sedimentary, crystalline, karstic, and metasedimentary, were subjected to exploratory statistical analysis, and 22 out of 26 parameters were subjected to multivariable analysis using Statistica (Version 7.0). From the PCA, 5 factors were sufficient to participate in the index, due to sufficient explanation of the cumulative variance. The matrix of factorial loads (for 1–5 factors) indicated 9 parameters related to water quality and 4 hydrological, with factor loads above ± 0.50, to be part of the hierarchical cluster analysis. The dendrogram allowed to choose the 5 parameters related to groundwater quality, to participate in the GWQI (hardness, total residue, sulphate, fluoride and iron). From the multivariable analyses, three parameters from a previous index—NGWQI, were not selected for the GWQI: chloride (belongs to the hardness hierarchical group); pH (insignificant factor load); and nitrate (significant factor load only for 6 factors), also, not a regionalized variable. From the set of communality values (5 factors), the degree of relevance of each parameter was extracted. Based on these values, were determined the relative weights (wi) for the parameters. Using similar WQI-NSF formulation, a product of quality grades raised to a power, which is the weight of importance of each variable, the GWQI values were calculated. Spatialization of 1369 GWQI values, with the respective colors, on the map of the state of Bahia, revealed good correlation between the groundwater quality and the index quality classification. According to the literature on water quality indexing, the GWQI developed here, using emerging technologies, is a mathematical tool developed as specific index, as it was derived using limits for drinking water. This new index was tailored to represent the quality of the groundwater of the four hydrogeological domains of the state of Bahia. Although it has a regionalized application, its development, using, factor analysis, principal component analysis, and hierarchical cluster analysis, participates of the new trend for WQI development, which uses rational, rather than subjective assessment. The GWQI is a successful index due to its ability to represent the groundwater quality of the state of Bahia, using a single mathematical formulation, the same five parameters, and unique weight for each parameter.

Author(s):  
Hazimah Haspi Harun ◽  
Mohamad Roslan Mohamad Kasim ◽  
Siti Nurhidayu ◽  
Zulfa Hanan Ash’aari ◽  
Faradiella Mohd Kusin ◽  
...  

The aim of this study was to propose a groundwater quality index (GWQI) that presents water quality data as a single number and represents the water quality level. The development of the GWQI in agricultural areas is vital as the groundwater considered as an alternative water source for domestic purposes. The insufficiency of the groundwater quality standard in Malaysia revealed the importance of the GWQI development in determining the quality of groundwater. Groundwater samples were collected from thirteen groundwater wells in the Northern Kuala Langat and the Southern Kuala Langat regions from February 2018 to January 2019. Thirty-four parameters that embodied physicochemical characteristics, aggregate indicator, major ions, and trace elements were considered in the development of the GWQI. Multivariate analysis has been used to finalize the important parameters by using principal component analysis (PCA). Notably, seven parameters—electrical conductivity, chemical oxygen demand (COD), magnesium, calcium, potassium, sodium, and chloride were chosen to evaluate the quality of groundwater. The GWQI was then verified by comparing the groundwater quality in Kota Bharu, Kelantan. A sensitivity analysis was performed on this index to verify its reliability. The sensitivity GWQI has been analyzed and showed high sensitivity to any changes of the pollutant parameters. The development of GWQI should be beneficial to the public, practitioners, and industries. From another angle, this index can help to detect any form of pollution which ultimately could be minimized by controlling the sources of pollutants.


2015 ◽  
Vol 3 (2) ◽  
pp. 38 ◽  
Author(s):  
Shashi Kant ◽  
Y.V. Singh ◽  
Lokesh Kumar Jat ◽  
R. Meena ◽  
S.N. Singh

<p>In sustainable groundwater study, it is necessary to assess the quality of groundwater in terms of irrigation purposes. The present study attempts to assess the groundwater quality through Irrigation Water Quality Index (IWQI) in hard-rock aquifer system and sustainable water use in Lahar block, Bhind of district, Madhya Pradesh, India. The quality of ground water in major part of the study area is generally good. In order to understand the shallow groundwater quality, the water samples were collected from 40 tube wells irrigation water. The primary physical and chemical parameters like potential Hydrogen (pH), Total Dissolved Solids (TDS), calcium (Ca<sup>2+</sup>), magnesium (Mg<sup>2+</sup>), sodium (Na<sup>+</sup>), potassium (K<sup>+</sup>), bicarbonate (HCO<sub>3</sub><sup>-</sup>), carbonate (CO<sub>3</sub><sup>2-</sup>), chloride (Cl<sup>-</sup>), and nitrate (NO<sub>3</sub><sup>-</sup>) were analyzed for (irrigation water quality index ) IWQI. The secondary parameters of irrigation groundwater quality indices such as Sodium Adsorption Ratio (SAR), Sodium Soluble Percentage (SSP), Residual Sodium Carbonate (RSC), Permeability Index (PI), and Kellies Ratio (KR) were also derived from the primary parameter for irrigation water quality index (IWQI). The IWQI was classified into excellent to unfit condition of groundwater quality based on their Water Quality Index (WQI). The IWQI (82.5%+15.0%) indicate that slightly unsustainable to good quality of ground water. Due to this quality deterioration of shallow aquifer, an immediate attestation requires for sustainable development.</p>


Author(s):  
Nguyen Hai Au ◽  
Tran Minh Bao ◽  
Pham Thi Tuyet Nhi ◽  
Tat Hong Minh Vy ◽  
Truong Tan Hien ◽  
...  

Groundwater in Phu My town is exploited essentially in Pleistocene aquifer and, used for many purposes like irrigation, domestic, production and animal husbandry. In this study, Groundwater Quality Index (EWQI) is calculated with Entropy weight method to determine the suitability of groundwater quality in study area. This method demonstrates the objectivity of each parameter calculated based on the degree of variability of each value and depends on the sample data source. The groundwater samples were collected from 17 wells in dry and wet seasons in 2017 with ten water quality parameters (pH, TDS, TH, Cl-, F-, NH4+-N, NO3--N, SO42-, Pb và Fe2+) were selected for analysising. The analysis results indicate groundwater quality is divided into 4 categories in this study area. In particular, over 70% of wells are "very good" water quality in both dry and wet seasons. Only 6% of wells are " water unsuitable for drinking purpose" of the total number of mornitoring wells in the study area.


2020 ◽  
Vol 42 (10) ◽  
pp. 452-462
Author(s):  
Jinhyo Lee ◽  
Hyunju Ha ◽  
Manho Lee ◽  
Mokyoung Lee ◽  
Taeho Kim ◽  
...  

Objectives : 17 water quality measurement networks (WQMNs, tributaries) in Seoul were analyzed by using NSFWQI and cluster analysis to provide basic data for future river water quality management so that citizens could easily and comprehensively understand the water quality information on the rivers in Seoul.Methods : For the past 3 years (2015~2017), in order to estimate WQI, 9 items, DO (% sat), Fecal coliform, pH, BOD, Temperature change (TC), TP, NO3-, Turbidity and Total solids, were selected from among the 19 water quality data measurement items produced monthly from 17 WQMNs in Seoul. WQI was derived and graded using NSFWQI and cluster analysis was performed using Ward Linkage Method, SOM (Self Organizing Map).Results and Discussion : Water quality of most water quality monitoring networks was BOD Ⅱ grade (slightly good) or higher and TP Ⅲ grade (normal) or higher according to the standard of water quality and water ecosystem river living environment, and NSFWQI was also 64 (Medium)~89 (Good). All showed good water quality. NSFWQI does not show a significant difference by season, so it is believed that it is affected by anthropogenic sources rather than seasonal effects. As a result of examining the correlation between NSFWQI and water quality level according to environmental standards, it was confirmed that R2 has a relatively good correlation with 0.78, and there is no clear difference between the two groups, and through this, it was found that the currently implemented water quality rating system and NSFWQI are well matched. As a result of cluster analysis using ward linkage method and SOM for 17 WQMNs, it was largely divided into 6 groups according to water quality characteristics.Conclusions : It is important to manage pollution sources to systematically manage river water quality as a water resource. It is therefore expected that by converting from the complicated and various water quality information such as is found in this study into a simple water quality index and grouping, the river water quality can be easily understood and can be utilized in the future as basic data for water quality management in Seoul.


2021 ◽  
Vol 30 (3) ◽  
pp. 546-561
Author(s):  
K. Mohammed Rizwan ◽  
V. Thirukumaran ◽  
M. Suresh

The aims of the current research are to assess the drinking water quality of the groundwater in the Gadilam River Basin, which is located in the northern part of Tamil Nadu, by identifying the groundwater quality index and examine its suitability for drinking. The current work determines the levels of groundwater quality parameters based on 120 groundwater samples; 50 samples from Archaean formation, 34 samples from Quaternary formation, 35 samples from Tertiary formation and the remaining sample from Cretaceous formation. Additionally, this research compares the determined levels with the various standards for drinking. Furthermore, the variability of parameters of the groundwater quality is explored in this paper by using the spatial interpolation method. The conclusion of this research reveals that the groundwater quality parameters such as Calcium (Ca2+), Magnesium (Mg2+), Nitrate (NO32-), Fluoride (F-), Sulphate (SO42-), Bi-carbonate (HCO3-) and Percentage of Hydrogen (pH) values are observed to be within the limiting value for WHO 2017 in all the formations during the seasons in which they were taken. The water quality index (WQI) values of the Archaean, Quaternary and Tertiary formations are found to be less than 100 meq/L in all stations in both seasons. In order of WQI, these stations come under the category of “Excellent” and “Good”. The Piper trilinear classification of groundwater samples fall in the field of mixed Ca-Mg-Cl, and No dominance, some of the samples represent Na-K, Cl types of water.


Author(s):  
Andrés Felipe Solis Pino ◽  
Carlos Andres Anacona Bambague ◽  
Bibiana Montoya ◽  
Efren Venancio Ramos Cabrera

It is widely accepted that the post-harvest processes of coffee are key factors in determining the final quality of the product. In the department of Cauca in Colombia, this stage is carried out empirically by the farmers of the region, using old methods that do not assure consistent quality. We propose a study to determine the best conditions of temperature and time in post-harvest for the coffee produced in the region. For this purpose, we carried the fermentation and honey process out on different samples of coffee of the Coffea Arabica species of the Castillo variety. Subsequently, the quality of the samples was determined through sensory evaluation by experts. Finally, descriptive statistical techniques applied to the resulting data, and component and hierarchical cluster analysis to find similarities between the samples. The results suggest that the honey process gets better evaluations in the cup profile over any fermentation condition.


2017 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Kailash Aher ◽  
Sharad Gaikwad

To identify the sources and quality of groundwater, the water samples were collected from 52 dug wells irrigation water in an area of 1089.82km2 and were analyses for pH, Conductivity, total dissolved solids, Calcium, Magnesium, Sodium, potassium, total hardness, Alkalinity (CO32−, HCO3−), sulphate, chloride, nitrate and fluoride to understand the (irrigation water quality index ) IWQI, The         secondary parameters of irrigation groundwater quality indices such as Sodium adsorption ratio (SAR), Residual sodium carbonate (RSC), Kelley’s ratio (KR), Sodium soluble percent (SSP), Permeability index (PI),Magnesium adsorption ratio (MAR),and CRI       (Corrosively ratio index) were calculated from the primary parameter for irrigation water quality index (IWQI). The IWQI was classified into excellent to unfit condition of groundwater quality based on their Water Quality Index (WQI). The IWQI (88%+12%) indicate that slightly unsustainable to good quality of ground water. But due to this quality deterioration of shallow aquifer, an immediate attestation requires for sustainable development.


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