Assessment Of Groundwater Quality Research Articles

Nitrate contamination in groundwater and its evaluation of non-carcinogenic health hazards from Arjunanadi River basin, south India

Nitrate (NO3-) contamination of groundwater is increasingly getting common in many places across India. Here, we present new data about nitrate pollution and the associated health consequences for infant, children, and adult population by evaluating 94 groundwater samples from the Madurai and Virudhunagar regions within the Arjunanadi River basin, situated at the southern region of India. Nitrate (9–221 mg/L) remained surpassed the WHO's recommended limit (>45 mg/L) in 34% samples. The piper diagram results specified that 75% of the samples fall in Mixed CaMgCl type. The correlation of nitrate results showed that groundwater of the region degraded by agricultural and industrial activities. The Nitrate Pollution Index (NPI) results of samples revealed significant pollution class, n = 18 (19%) and very significant pollution class, n = 26 (28%) in the study region. Its spatial distribution covered an area of 456.3 km2 in the risk zone with more than permissible nitrate. Among the shallow aquifers, about 16% of whole samples were in the high risk and 9% in very high-risk. Similarly, about 6% samples from deep aquifers were also in the category of high risk. The Water Quality Index (WQI) of groundwater samples indicateed 39% as good, 48% as poor and 9% as very poor to unsuitable. The health risk assessment from intake (HQintake) and skin contact (HQdermal) suggested 64%, 45% and 32% of samples with THI >1 pose hazard for infant, children, and adult population, respectively. The health risks and assessing groundwater quality indicated the necessity of regular groundwater quality monitoring for better long-term health management in this region.

Deciphering groundwater pollution in the Lower Anayari Catchment: insights from using δ2H, δ18O, PMF, and APCS-MLR receptor model.

This research provides a comprehensive analysis of groundwater pollution in the Lower Anayari Catchment (LAC) through δ2H and δ18O isotopic analysis, along with positive matrix factorization (PMF) and PCS-MLR receptor models. Forty groundwater samples were collected from hand-dug wells and equipped boreholes across the LAC. Flame photometry for Na+ and K+, complexometric titration for Ca2+, ion chromatography for Cl-, F-, NO3-, SO42-, and PO43-, and atomic absorption spectrometry for Mg2+, Fe, Pb, Cd, As, and Ni were analytical techniques/instruments employed. In regard to cations, Na+ has the highest average concentration of 63.0 mg/L, while Mg2+ has the lowest at 2.58 mg/L. Concerning the anions and nutrients, Cl- has the highest mean concentration of 18.7 mg/L, and Fl- has the lowest at 0.50 mg/L. Metalloids were detected in trace amount with Fe displaying the highest mean concentration of 0.077 mg/L whereas Cd and As recorded lowest (0.001 mg/L). The average values for groundwater δ18O and δ2H were - 3.64‰ and - 20.7‰, respectively; the average values for rainwater isotopic composition were - 3.41‰ for δ18O and - 17.4‰ for δ2H. It is believed that natural geological features, particularly biotite granitoid and volcanic flow/subvolcanic rocks from the Birimian Supergroup, significantly influence groundwater mineralisation. Additionally, the impact of anthropogenic activities on water quality, with urban development and agricultural practices, may be attributed to increasing levels of certain contaminants such as Fe, Ni, NO3-, and PO43-. This research contributes to the broader field of hydrological study and provides practical implications for managing and conserving water resources in similar contexts. The innovative combination of isotopic and statistical analyses sets a new standard for future studies in groundwater quality assessment, emphasising the need for comprehensive approaches that consider both geological characteristics and human impacts for sustainable water resource management.

Assessment of surface and groundwater quality in Tikamgarh city, Madhya Pradesh, India

Surface water and groundwater are primary resources for communities living in arid and semi-arid regions. The expansion of industrial and agricultural practices has raised pressure on natural resources. Water quality assessment provides valuable information about potential of resources for intended uses. The correlation study was carried out on the physicochemical parameters of surface water and groundwater in the Tikamgarh city. The physicochemical parameters, such as pH, total dissolved solids (TDS), total hardness (TH), calcium (Ca2+), magnesium (Mg2+), total alkalinity (TA), sulphate (SO42-), fluoride (F-), iron (Fe), nitrate (NO3-), chloride (Cl-) and turbidity were analysed to determine correlation between parameters. The grab sampling technique was adopted to collect water samples from selected dug wells and reservoirs. The results of physicochemical parameters were fitted in the correlation coefficient equation to predict probable values of different parameters for selected locations. Results of the correlation study showed that calcium and TH are strongly correlated, followed by TH with chloride. However, Ca2+, TH, Cl-, TA, TDS, SO42-, and iron show a high correlation. The findings show that water quality can be managed by controlling TH and TDS concentrations through conventional and non-conventional treatment methods.

Hydrogeochemical characterization of groundwater in mountainous catchment and its suitability for drinking purposes in Irob, Tigray, Northern Ethiopia

Abstract The primary source of drinking water in Ethiopia's semi-arid mountainous regions is groundwater. The present study aims to assess the hydrogeochemical characteristics of low-grade basement rocks dominated by mountainous catchments. Moreover, it examines the suitability of the groundwater quality for drinking purposes in Irob, Tigray, northern Ethiopia. However, relatively little is known about the water chemistry and groundwater quality of the resources in the area. Fifteen samples of groundwater were collected and examined for ions according to standard procedures. The outcomes were assessed against the World Health Organization (WHO) drinking water quality criteria. To identify the source of dissolved ions and the process involved, graphic interpretations were applied. The results show that Ca–Mg–SO4–HCO3 and Ca–SO4–HCO3 were the dominant water types. Gibbs plots and ionic ratios reveal that silicate weathering, carbonate dissolution and ion exchange control water chemistry. Furthermore, the findings reveal that 60, 80, 46.67, 46.67, 60, 6.67, 60 and 53.33% of samples are above the safe limits of the WHO for hardness, alkalinity, total dissolved solids, electrical conductivity, calcium (Ca2+), potassium (K+), bicarbonate (HCO3-) and sulfate (SO42-), respectively. Consequently, the groundwater quality assessment demonstrates that the water sources in lower parts of the catchment are unsuitable for drinking.

Physico-Chemical Quality Assessment of Ground Water in Kathmandu Valley and Siraha District

A key element in maintaining human health is the quality of drinking water which is a vital component of natural resources. This study was conducted to assess the ground water quality in the Kathmandu Valley and Siraha district from October 2022 to March 2023 in the Water Engineering and Training Centre, Ratopul, Kathmandu. A total of 123 water samples were collected from various wells and borings around the Kathmandu Valley and Siraha district and were subjected to physicochemical investigation following the standard techniques for water sample collection and analyzed by methods as described in the American Public Health Association (1998). The pH, conductivity, turbidity, ammonia concentration, and iron content were found to exceed National Drinking Water Quality Standard guidelines value in 21.95%, 3.25 %, 53.65 %, 47.15 %, and 18.7 % of total water samples respectively. All water samples had total hardness and chloride levels within the acceptable range. The arsenic content of all samples except one well water sample from Siraha was found within a permissible level. The findings suggest that water quality is not satisfactory, which could lead to various water-borne illnesses. Therefore, proper water purification techniques should be used before consumption.

Assessment of groundwater quality using Entropy‑Weighted Quality Index (EWQI) and multivariate statistical approaches in Heilongdong Spring Basin, Northern China

Assessment of groundwater quality using Entropy‑Weighted Quality Index (EWQI) and multivariate statistical approaches in Heilongdong Spring Basin, Northern China

Hydrogeochemical evolution processes, groundwater quality, and non-carcinogenic risk assessment of nitrate-enriched groundwater to human health in different seasons in the Hawler (Erbil) and Bnaslawa Urbans, Iraq

The main objectives of this research are to assess groundwater, a primary source of drinking water in the urban areas of Hawler (Erbil) and Bnaslawa in northern Iraq, and the non-carcinogenic human health risks of nitrate contamination associated with drinking water quality. For this purpose, twenty-seven groundwater samples were collected from wells to assess the hydrogeochemical characteristics and groundwater quality for both natural and anthropogenic purposes during the wet (May 2020) and dry (September 2020) seasons. During the wet and dry seasons, NO3− in groundwater ranged from 14.00 to 61.00 mg/L and 12.00 to 60.00 mg/L, with an average value of 35.70 and 29.00 mg/L, respectively. Approximately 25.92% of the samples exceeded the permissible limit of the WHO (2011) drinking water standard. The ratios of NO3−/Na+ vs. Cl−/Na+ and SO42−/Na+ vs. NO3−/Na+ indicate the effect of agricultural activities and wastewater leaking from cesspools or septic tanks on the quality of groundwater during the wet and dry seasons. The entropy weighted water quality index method ranked 62.5% and 75% of the urban groundwater as not recommended for drinking, and the remaining samples are moderately suitable in both wet and dry seasons. The non-carcinogenic human health risk assessment displayed that during the wet and dry seasons, 29.6% and 25.9% of adults, 48% and 30% of children, and 48.1% and 29.6% of infants were exposed to increased concentrations of nitrate in groundwater. Due to high nitrate in drinking water, non-carcinogenic human health risk levels vary as infant > child > adults. The main findings obtained from this study can assist policymakers in better understanding the hydrogeochemical properties of groundwater in terms of drinking water safety, thereby facilitating the management of water resources to take the necessary measures.

AquMADE: A GIS-based web application to assess groundwater quality by introducing a risk-based irrigation water quality index (RB-IWQI)

Groundwater quality monitoring plays a vital role in effective water management across all groundwater basins. The provision of decision support systems can assist decision-makers in strategic planning and the conservation of groundwater resources. In this study, AquMADE—a user-friendly and comprehensive web application—is developed to integrate GIS and multi-criteria decision-making methods seamlessly for modifying the irrigation water quality index. AquMADE serves multiple functionalities. Firstly, it empowers decision-makers to import, interpolate, and visualize collected data, enabling a holistic view of the information at hand. Secondly, it offers the flexibility for decision-makers to adjust the weights of various parameters through the utilization of the analytical hierarchy process, taking into consideration their risk attitudes during the aggregation process using ordered weighted averaging method. Finally, the incorporation of sensitivity analysis methods allows for the evaluation of the impact of changes in inputs, such as criteria weights and aggregation methods, on the resulting outputs. The system underwent user testing in Khoy City, Iran, where it received positive feedback. The assessment revealed that the system performed satisfactorily in terms of functionality, interactivity, and ease of use.

Groundwater quality and non-carcinogenic element health risks assessment using multi-technical models: A case of the deep aquifer of the complex terminal in Ouargla city (southeastern Algeria)

The purpose of this work was to evaluate the groundwater quality and the health hazards related to non-carcinogenic elements present in the Complex Terminal (CT) Ouargla city. Thirty (30) samples were taken and physico-chemically analyzed collected from deep boreholes located in study area. Fluoride concentrations ranged between 1.07 and 3.7 mg/l, with 54% of samples having a value >1.5 mg/l as per potability limit. According to the fluoride pollution index (FPI), 63.67% of the boreholes were severely contaminated with F−. However, nitrate pollution index (NPI) revealed that approximately 71% of the samples showed no contamination. The pollution index of groundwater (PIG) ranging from 1.34 to 2.85 indicate the majorit of groundwater samples in the search zone was contaminated for human consumption. Based on the entropy water quality index (EWQI), 30% of samples had poor quality, while 70% were unfit for drinking. According to the statistical analysis used in this study, the dissolution of fluoride-rich carbonate rocks under high HCO3− contents enables the liberation of F− from fluorine-bearing minerals like calcite and fluorite. Regarding non-carcinogenic risks, the Hazard quotient (HQ) fluoride was obtained with a huge difference in exposure dose in children (0.89–3.08), women (0.62–2.13) and men (0.54–1.85), respectively. HQ nitrate values ranged from 0.08 to 1.40, 0.06–0.97 and 0.05–0.84 for men, women and children, correspondingly. The total hazard index (THI) clearly show that fluoride presents a higher health risk than nitrate, revealing that 53.3%, 66.7%, and 100% of the samples show that men, women and children, at risk respectively. It has been proven to be more susceptible to health hazards since it may be exposed to non-carcinogenic elements, and to avoid a further worsening of the health situation, those responsible and decision-makers will have to treat the water appropriately, identify the affected people and provide them with the necessary medical care.

Groundwater quality assessment using water quality index and principal component analysis in the Achnera block, Agra district, Uttar Pradesh, Northern India

The qualitative and quantitative assessment of groundwater is one of the important aspects for determining the suitability of potable water. Therefore, the present study has been performed to evaluate the groundwater quality for Achhnera block in the city of Taj, Agra, India, where groundwater is an important water resource. The groundwater samples, 50 in number were collected and analyzed for major ions along with some important trace element. This study has further investigated for the applicability of groundwater quality index (GWQI), and the principal component analysis (PCA) to mark out the major geochemical solutes responsible for origin and release of geochemical solutes into the groundwater. The results confirm that, majority of the collected groundwater samples were alkaline in nature. The variation of concentration of anions in collected groundwater samples were varied in the sequence as, HCO3− > Cl− > SO42− > F− while in contrast the sequence of cations in the groundwater as Na > Ca > Mg > K. The Piper diagram demonstrated the major hydro chemical facies which were found in groundwater (sodium bicarbonate or calcium chloride type). The plot of Schoellar diagram reconfirmed that the major cations were Na+ and Ca2+ ions, while in contrast; major anions were bicarbonates and chloride. The results showed water quality index mostly ranged between 105 and 185, hence, the study area fell in the category of unsuitable for drinking purpose category. The PCA showed pH, Na+, Ca2+, HCO3− and fluoride with strong loading, which pointed out geogenic source of fluoride contamination. Therefore, it was inferred that the groundwater of the contaminated areas must be treated and made potable before consumption. The outcomes of the present study will be helpful for the regulatory boards and policymaker for defining the actual impact and remediation goal.

Effective Deep Learning based Prediction Model for Groundwater Quality Assessment using Physio-chemical Parameters

<p>The purpose of this study is to anticipate and investigate the groundwater quality in the regions of the Cauvery basin. In the post-monsoon season of 2020, 800 samples were collected from 200 different places for this paper. The AlexNet model is used in this book to forecast the water quality. In order to examine the groundwater quality, the anticipated groundwater samples are analyzed using main cations (K+, Mg2+, Ca2+, and Na+), major anions (NO2- +NO3-, CO3-, F-, HCO3-, Cl-, and SO42-), hardness, pH, and Electrical Conductivity (EC). The accuracy, specificity, and sensitivity of the AlexNet model are used in this publication to validate its efficacy. Validating the following metrics determines if water is suitable for drinking and irrigation: sodium percentage, magnesium ratio, Kelly's ratio, sodium adsorption ratio, water quality index (WQI), and residual sodium carbonate (RSC). According to the research, the AlexNet model predicted water quality with 93%, 94.57%, and 91.47% accuracy, specificity, and sensitivity, respectively. According to the experimental results, the WQI value shows that 22% of the collected samples are acceptable for drinking, 63% are suitable for drinking, and the other 15% are only fit for irrigation and should not be consumed.</p>

Groundwater quality and potential analysis using geospatial techniques: The case of Ashanti Region in Ghana

The ecosystem and economy's reliance on clean water is influenced by various factors such as geology, topography, soil types, activities, and the presence of plants and animals. The Ghana Water Company is encountering difficulties in delivering water to consumers in the Ashanti Region due to the shortage of surface water resources, leading to water rationing in the area. Furthermore, poor waste disposal practices, illegal mining, use of fertilizers, and industrial activities have resulted in surface and groundwater source damage. Therefore, there is a need to implement a reliable, simple, and timely method to assess groundwater quality. This study aims to employ GIS and RS techniques to evaluate groundwater quality and potential in the Ashanti Region, Ghana. The Water Quality Index (WQI) was estimated using pH, Total Dissolve Solid (TDS), Chloride, Total Hardness (TH), Nitrate, Temperature, Turbidity, Iron, and Electrical Conductivity (EC). The study then used the WQI distribution to conduct a groundwater potential analysis to identify suitable areas for borehole placement. Digital thematic layers and maps were developed to expose the spatial distribution of water quality parameters, enabling the identification of groundwater pollution control and remedial measures. The study estimated the region's groundwater potential using an integrated GIS and Analytical Hierarchical Process (AHP) technique, grouping under excellent, good, fair, and poor potential. The WQI in the Ashanti Region ranged from 5.208 to 134.232, with 32.252% of the study area having an excellent WQI and 60.168% of the study area having a good WQI. Poor water quality covered 7.550% of the study area. The results showed that the GIS-based AHP approach accurately mapped the spatial distribution of WQI and Groundwater Potential Zones (GWPZ). This information is helpful to planners in water resource management in groundwater exploration and future planning. Policymakers and stakeholders must ensure that groundwater sources are protected from pollution.

Artificial Neural Network Assessment of Groundwater Quality for Agricultural Use in Babylon City: An Evaluation of Salinity and Ionic Composition

Artificial Neural Network Assessment of Groundwater Quality for Agricultural Use in Babylon City: An Evaluation of Salinity and Ionic Composition

A review of the status, challenges, trends, and prospects of groundwater quality assessment in Nigeria: an evidence-based meta-analysis approach.

With the imminent industrial growth and population increase, Nigeria will continue to experience significant shifts in the quality of water, with a rise in emerging contaminants. This will increase the irregularity and complexity of the water quality information. Therefore, using the PRISMA meta-analysis approach, this review systematically identified the commonly used water quality assessment techniques in Nigeria, the drawback in the application of these techniques as well as the gaps in the area of water quality assessment and monitoring from 2003 to 2023. Recommendations were also made based on the evaluation of a new research direction; through the review of the effectiveness of advanced techniques for monitoring water quality in Nigeria. Sixty-eight published articles were chosen for the meta-analysis while the VOSviewer program was used to perform bibliographic coupling and visualization. The review revealed that the application of machine learning in water quality prediction has not been well explored in Nigeria. This is attributed to limited data availability and poor funding by the government. It was found that southwestern Nigeria has a greater amount of research on groundwater quality monitoring and evaluation than other regions. The variability was explained by variations in the underlying geology, aquifer features; variability in anthropogenic activities, and level of literacy among various geopolitical zones. Further studies should focus on the application of soft-computing and integrated biomonitoring techniques for effective prediction and monitoring of emerging contaminants for improved water quality. Effective collaboration between environmental stakeholders and government agencies is recommended for effective water resource sustainability.

Assessment of Groundwater Quality around Amaenyi and State Secretariat Dumpsites in Awka, Southeastern Nigeria

The effects of two dumpsites located at Amaenyi and State Secretariat Awka on groundwater resources was investigated using hydrochemical parameters. A total of eighteen (18) groundwater samples were collected from areas in the vicinity of the dumpsites and analysed for various hydrochemical and biological parameters using standard methods. The results of the analysis were subjected to interpretations using various methods such as spatial distribution maps, water quality indices (WQI, HPI, Cd and MEI), comparing with international and local standards and statistical analysis. The results indicate that parameters such as Ec, TDS, Na+, K+, Ca2+, Cl-, NO3- and SO42- were in compliance with the acceptable limits of World Health Organization and Nigerian Drinking Water Standard. However, HCO3-, total hardness, COD, BOD, DO1, DO5, Pb, Fe, Cd and Hg exceeded the permissible guidelines in some samples. WQI rated 20% of the samples in Amaenyi as excellent, 30% (good), 10% (poor), 20% (very poor) and the remaining 20% is unfit for consumption while in State Secretariat area, 37.5% was very poor and the remaining 62.5% was unfit for consumption. HPI rated groundwater as highly contaminated while Cd classified most of the water samples to indicate low contamination except for sample A1 which was highly contaminated. Also, MEI indicated that groundwater has low heavy metal pollution. The correlation analysis indicates strong positive relationship between BOD, COD, DO1, DO5, total hardness, bicarbonate, calcium and sulphate, lead, magnesium and chloride. It was concluded that groundwater in the study area is mostly contaminated and the contaminants is attributed to be from the waste dumpsites and other anthropogenic activities.

Assessment of groundwater quality with special emphasis on fluoride contamination: a case study in Thar Desert, Pakistan

Assessment of groundwater quality with special emphasis on fluoride contamination: a case study in Thar Desert, Pakistan

Water Quality Assessment of Groundwater Using Multivariate Statistical Techniques: A Case Study of Mogadishu, Banadir Region, Somalia

This study was carried out to assess the groundwater quality around the Mogadishu area, Banadir region, Somalia. Multivariate statistical techniques such as factor analysis (FA), principal component analysis (PCA) and cluster analysis (CA)were applied to 22 groundwater samples collected from boreholes and dug wells in the coastal line districts namely: Wadajir, Kaxda and Dharkinley districts of Banadir region, Somalia. Correlations among 14 hydrochemical parameters were statistically examined. A two-factor model is suggested and explains over 82.4% of the total groundwater quality variation. Factor Analysis (FA) revealed significant variables including electrical conductivity (EC), pH value and other parameters such as K<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Na<sup>+</sup>, SO<sub>4</sub><sup>2-</sup> and hardness expressed as CaCO<sub>3</sub>, Chlorine, Fluoride, B, S, Si, and NO<sub>3</sub> which are responsible for variations in groundwater quality and affect water chemistry. The results were compared with the World Health Organization (WHO) standard guidelines. Geographic Information System (GIS) was used to create the spatial distribution maps of water quality parameters. Cluster Analysis (CA) grouped all sites into three zones based on spatial similarities and dissimilarities of physiochemical properties. The pH value and Boron, fluoride calcium, magnesium, sulfide, potassium, and Silica are well within the desirable limit at all locations. However, the concentration of conductivity chloride, hardness as CaCO<sub>3</sub>, sulfate, nitrate, and Sodium in all samples exceeded the desirable WHO maximum permissible limit. The study reveals that the groundwater quality changed due to anthropogenic and natural influences such as natural weathering processes. As a result of this the qualities of the boreholes and dug well water samples were therefore not suitable for human consumption without adequate treatment. Regular monitoring of groundwater quality, abolishing unhealthy waste disposal practices, and introducing modern techniques are recommended.

Hydrogeochemistry and Water Quality Index for Groundwater Sustainability in the Komadugu-Yobe Basin, Sahel Region

The assessment of hydrochemical characteristics and groundwater quality is crucial for environmental sustainability in developing economies. This study employed hydrogeochemical analysis, geospatial analysis, and groundwater quality index to assess hydrogeochemical processes and quality of groundwater in the Komadugu-Yobe basin. The pH, total dissolved solids (TDS), and electrical conductivity (EC) were assessed in situ using a handheld portable electrical conductivity meter. The concentrations of the major cations (Na+, Ca2+, Mg2+, and K+), were analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The major anions (chloride, fluoride, sulfate, and nitrate) were analyzed via ion chromatography (IC). Total alkalinity and bicarbonate were measured in situ using a HACH digital alkalinity kit by the titrimetric method. Hydrochemical results indicate some physicochemical properties of the groundwater samples exceeded the maximum permissible limits as recommended by the World Health Organization guidelines for drinking water. Gibbs diagrams indicate rock–water interaction/rock weathering processes are the dominant mechanisms influencing the groundwater chemistry. Groundwater is predominantly Ca2+-Mg2+-HCO−3 water type, constituting 59% of the groundwater samples analyzed. The groundwater quality index (GWQI) depicted 63 and 27% of the groundwater samples as excellent and good water types for drinking purposes, respectively. This study further relates the interaction between geology, hydrochemical characteristics, and groundwater quality parameters. The results are essential to inform a sustainable management strategy and protection of groundwater resources.

Z-number based assessment of groundwater vulnerability to seawater intrusion

Groundwater (GW) quality assessment is an essential issue, especially in arid and semi-arid regions, due to its critical role in obtaining requirements for freshwater. The GALDIT method is widely recognized as a practical approach for assessing GW susceptibility, which considers six key factors, including the occurrence of groundwater (G), hydraulic conductivity of the aquifer (A), elevation of groundwater above sea level (L), distance from the shoreline (D), impact of existing seawater intrusion (I), and thickness of the aquifer (T). The GALDIT method, being an unsupervised model, has a drawback in that it depends on expert opinion for parameter ranking, leading to an increase in uncertainty. To address this uncertainty and evaluate the susceptibility of the aquifers of Urmia lake basin to saltwater intrusion, this study employed the Z-number which is a novel adaptation of Fuzzy Logic (FL). In contrast to classic FL that does not account for data reliability, the Z-number approach considers both constraints and data reliability, making it a more effective method to manage data uncertainty compared to classic fuzzy models. To illustrate this methodology, the GALDIT parameters (inputs) and Electrical Conductivity (EC) values (outputs) were employed to determine the vulnerability of aquifers. Additionally, the GALDIT method was utilized as a benchmark model to evaluate the inherent vulnerability of aquifers, and its outcomes were compared with those of the proposed model. Upon analyzing the results, it was found that the Z-number Based Modeling (ZBM) not only outperformed the GALDIT method but also enhanced the quality of outcomes by 85% and 35% based on Heidke Skill Score (HSS) and Total Accuracy (TA) criteria compared to the classic FL.

A novel approach for prediction of groundwater quality using gradient boosting-based algorithms

ABSTRACT This study explores the potential of the GPBoost approach for groundwater quality assessment in comparison to three other gradient boosting-based algorithms. Three methods, random search, grid search, and Bayesian optimization were used to find the optimal values of various hyperparameters with all four-gradient boosting-based algorithms. One hundred and two samples of Entropy weighted water quality index with 14 input parameters are used for assessing groundwater quality. The calculated EWQI values for drinking range between 80.4 and 394.96 in pre-monsoon and 39.6 to 338.79 during the post-monsoon period. Moreover, spatial distribution maps displayed that the central portions of the study area fall under medium water quality. The performances of models were compared based on multiple statistical criteria, including Correlation Coefficient (CC), root mean square error (RMSE), and mean absolute error (MAE). The results reveal that the CC value by all modeling approaches is more than 0.93, suggesting a comparable performance by all methods. Results in terms of RMSE values in predicting the EWQI values suggest GPBoost (random search) model performed better than the other three models, thus suggesting a competitive performance by GPBoost in comparison to other gradient boosting-based approaches. Relative importance analysis provided by random and grid search methods highlights the significance of NO3 −, Mg2+, TDS, EC, and TH as important input parameters for predicting EWQI.