Assessment Of Groundwater Quality Research Articles

Hydrogeochemical assessment of groundwater quality for drinking and irrigation applying groundwater quality index (GWQI) and irrigation water quality index (IWQI)

In recent times, the contamination of groundwater in the extended part of Chota Nagpur Plateau becomes a big concern. The demand of high-quality drinking and irrigation water has been significantly augmented. Consequently, productivity and fertility of soils are being reduced in the recent years due to use of low quality irrigation water. Thus, it is crucial to know the groundwater quality for the appropriate planning and management of groundwater resources to determine its use for drinking and irrigation purposes. Therefore, the principal objectives of this study are (i) to evaluate the magnitude and spatial variations of groundwater quality using the Groundwater Quality Index (GWQI) for drinking and (ii) to examine the irrigation suitability of groundwater using irrigation water quality index (IWQI). Sodium absorption ratio (SAR), Soluble sodium percentage (SSP), Magnesium hazard (MH), Kelly's index (KI), Permeability Index (PI) have been applied for suitability of irrigation water. Result showed that in 2021, GWQI values vary from 51.75 to 171.18 and seven blocks of the Purulia district among twenty blocks have poor drinking water quality while in 2022 it ranges from 70.27 to 178.45 and eight blocks stand poor water quality. In terms of irrigation water quality, Purulia II and Hura blocks come under the ‘doubtful’ or ‘poor ‘categories in pre and post-monsoon seasons for both the years. Hydro-chemical facies through Piper, USSL and Durov's diagram showed medium to high salinity and low to medium sodium hazards in this region. Feldspar and biotite minerals of granite and gneiss accelerate the bicarbonate and chloride ions in groundwater. Non point sources are also responsible for water quality deterioration in this agricultural dominated region. These research findings will help to policy makers and administrators for the management of groundwater resources and agricultural sustainability particularly in the dryland region.

Metaheuristic approaches for prediction of water quality indices with relief algorithm-based feature selection

Monitoring and assessing groundwater quality are important for sustainable water resource management. Therefore, the present study aimed to analyze and predict the water quality indices using metaheuristics algorithms. Groundwater samples were acquired from 26 tube wells periodically, and laboratory analysis was performed in the soil and water laboratory, Water Technology Centre (WTC), ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India. Water quality parameters such as pH, electrical conductivity (EC), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl−), carbonate (CO32−), bicarbonate (HCO3−) and sulphate (SO42−) were used for the computation of water quality indices. The relief algorithm was used for the selection of the best input combinations. Seven meta heuristics algorithms viz., Reduced Error Pruning Tree (REPTree), Random Forest (RF), Bagging, Additive Regression (AdR), M5Preuning Tree (M5P), Random Subspace (RSS), and Artificial Neural Networks (ANN) were trained and tested for Water Quality Index (WQI), and the best four candidate models, i.e., M5P, ANN, RF, and RSS were validated for the prediction of Kelly ratio (KR), sodium adsorption ratio (SAR), permeability index (PI), and percent sodium (%Na). The performance of models was assessed using statistical indicators, i.e., mean absolute error (MAE), root mean squared error (RMSE), Willmott index (WI), Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R), and visual graphics (i.e., Taylor diagram and radar chart). On a quantitative comparative scale, the M5P model performed better for predicting WQI (WI = 0.997, NSE = 0.988, MAE = 7.173, RMSE = 10.769 and R = 0.999) and % Na (WI = 901, NSE = 0.692, MAE = 3.817, RMSE = 5.005 and R = 0.853). The ANN model had a significant edge over other models for predicting indices namely, KR (WI = 0.844, NSE = 0.625, MAE = 0.121, RMSE = 0.164 and R = 0.825), PI (WI = 0.987, NSE = 0.949, MAE = 2.508, RMSE = 3.269 and, R = 0.981), and SAR (WI = 0.981, NSE = 0.916, MAE = 0.314, RMSE = 0.385 and R = 0.976). The result indicated that the M5P model has the potential to predict the water quality indices even under limited input parameters scenarios in the sub-tropical climatic condition. Also, study findings revealed that the relief algorithm based input feature selection could be used for assessing water quality indices. The outcome of the present study would be of interest to policymakers or irrigation planners to achieve groundwater sustainability in terms of water quality suitability for distinct applications and remedial measures to enhance groundwater quality.

Assessment of Groundwater Quality in Some Selected Residences of Kano Municipal Local Government Area, Kano State, Nigeria

Assessment of Groundwater Quality in Some Selected Residences of Kano Municipal Local Government Area, Kano State, Nigeria

Hotspot and accumulated hotspot analysis for assessment of groundwater quality and pollution indices using GIS in the arid region of Iran.

Because groundwater quality representatives for drinking usage (i.e., Schuler method, Nitrate and Groundwater Quality Index) have been abruptly changing due to extreme events induced by global climate change and over-abstracting, applying an efficient tool for their assessments is vitally important. While hotspot analysis is introduced as an efficient tool concentrating on sharp changes in groundwater quality, it has not been closely examined. Accordingly, this study is an attempt to determine the groundwater quality proxies and assess them through hotspot and accumulated hotspot analyses. To this end, a GIS-based hotspot analysis (HA) applying Getis-Ord Gi* statistics was used. The accumulated hotspot analysis was launched to identify the Groundwater Quality Index (AHA-GQI). Moreover, Schuler method (AHA-SM) was utilized to determine the maximum levels (ML) for the hottest hotspot and the lowest levels (LL) for the coldest cold-spot, and compound levels (CL). The results revealed that a significant correlation (r = 0.8) between GQI and SM was observed. However, the correlation between GQI and nitrate was not significant and the correlation between SM and nitrate was so low (r = 0.298, sig > 0.05). The results also demonstrated that using hotspot analysis on only GQI, the correlation between GQI and SM increased from 0.8 to 0.856, while using hotspot analysis on both GQI and SM increased the correlation to 0.945. Likewise, when GQI was subjected to hotspot analysis and SM underwent accumulated hotspot analysis (i.e., AHA-SM (ML)), the correlation degree increased to the highest extent (i.e., 0.958), indicating the usefulness of including the hotspot analysis and accumulated hotspot analysis in the evaluation of groundwater quality.

Hydrogeochemical Assessment of Groundwater Quality and Geological Influence in Igarra and environs, Southwestern Nigeria

The impact of Geology on groundwater is not fully appreciated in many Nigerian groundwater quality literature. This study investigates the influence of Geology on the hydrogeochemical makeup of groundwater in Igarra and environs, Nigeria. Igarra and environs is underlain by metasediments intruded by Pan African Granites. Ten water samples were collected and analyzed in the laboratory to determine their chemical composition. The results revealed that the pH of most samples was slightly acidic to mainly alkaline, with high electrical conductivity (EC) and total dissolved solids (TDS) values. Correlation and regression analyses showed that the TDS, EC, salinity, chemical oxygen demand, dissolved oxygen, and major and minor constituents positively influenced the pH of the groundwater. Hierarchical cluster analysis demonstrated that the water samples had different compositions and concentrations based on local geological influences. The water samples from Granite, Quartzites, Migmatites and Gneiss rock types shared similar characteristics and had a lower concentration of minerals than the water samples taken from the Quartz Mica Schists and Metaconglomerates. The water in Igarra was predominantly Magnesium Bicarbonate type. However, some of the water samples exceeded the drinking standards for TDS, EC, Cl, Fe, Cr, Cd, and Pb. The study recommends the inclusion of biological parameters to gain a clearer picture of the water quality, particularly from the anthropogenic point of view.

Geoelectrical, hydrochemical, and health risk assessment of groundwater quality in Fountain University, Osogbo, Nigeria

Geoelectrical method and physiochemical analyses were applied to obtain subsurface resistivity variation and water quality assessment respectively in Fountain University, Osogbo, Osun State. A young academic institution with a measurable growing population is seriously concerned with the hygienic situation within its environment, especially water quantity and quality. The geophysical method was employed to determine the subsurface groundwater potentials via vertical electrical sounding (VES) using the Schlumberger array. Ten (10) water samples were collected from different locations within the study area and analyzed for physiochemical parameters and trace metals using standard procedure. Water quality index (WQI), exceedance, and human health risk index were determined. All parameters estimated were below the WHO permissible limits except the pH and iron concentration. WQI values of the ten collected water samples reflected 100% excellent grade for drinking. Chronic dietary intake (CDI) is in the order of Fe >Zn > Cu for both children and adults. The VES (9 location points were studied) data revealed four to five geo-electric layers which corresponded to the topsoil, lateritic clay, weathered layer, fractured basement, and fresh basement with thickness ranges of 0.5 to 39.6 m, while resistivity values vary from 27.5 to 5432.6 Ωm. The study observed and recommended that boreholes could be sunk at VES 1, 6, and 7 at depths between 26.1 to 39.6 m for exploitation of good quality water along with continuous monitoring of groundwater quality to maintain the good water quality area, hence the safety of the environment.

Assessment of Groundwater Quality around Nagole in Hyderabad

Water is one of the most essential elements for survival of living organism. Water consumption of a person is 135l/c/day. In current scenario, due to increase in population leads to occupy the rivers space. Now a days due to deteriorating natural water bodies, human depends upon sub surface water and ground water to meet their daily needs. In future these subsurface water source also become deteriorate due to over exploitation. In future it leads to subsurface and surface water scarcity so, many researchers finding alternate sources, sustainable water management techniques for proper monitoring the present sources to reduce water demand. There are 400 small and biglakes available in Hyderabad City. Out of which 169 lakes were notified by Hyderabad Metropolitan Development Authority (HMDA) for protection and conservation of water spread area. We have selected Nagole in Hyderabad City of Telangana state for conducting a study on assessing groundwater quality. Thirteen parameters were chosen for the analysis such as pH, EC, Total dissolved solids, Turbidity, Alkanlinity, Chlorine, Sodium, Potassium, Total hardness, BOD, COD, Fluorine, Sulphate. Finally, results of the analysis were compared with water quality standards such as BIS 10500 (1991) of water sample. From this study, it was observed that EC exceeded the Permissible limit which impacts of more ion presence in the samples, alkalinity also higher than the permissible limit. The high content of alkalinity in water results in formation of chemical scale or precipitate which would clog piping or form a scale on filter, sodium exceeds the permissible limit. These parameters were higher in few sampling station while other parameters were within the permissible limits

Assessment of Surface and Ground water Quality in Hyderabad

Water is one of the most essential elements for survival of living organism. Water consumption of a person is 135l/c/day. In current scenario, due to increase in population leads to occupy the rivers space. Nowa days due to deteriorating natural water bodies, human depends upon sub surface water and ground water to meet their daily needs. In future these subsurface water source also become deteriorate due to over exploitation. In future it leads to subsurface and surface water scarcity so, many researchers finding alternate sources, sustainable water management techniques for proper monitoring the present sources to reduce water demand. There are 400 small and big lakes available in Hyderabad City. Out of which 169 lakes were notified by Hyderabad Metropolitan Development Authority (HMDA) for protection and conservation of water spread area. We have selected Himayath Sagar, Osman Sagar, Peerzadiguda in Hyderabad City of Telangana state for conducting a study on assessing groundwater quality. Thirteen parameters were chosen for the analysis such as pH, EC, Total dissolved solids, Turbidity, Alkanlinity, Chlorine, Sodium, Potassium, Total hardness, BOD, COD, Fluorine, Sulphate. Finally, results of the analysis were compared with water quality standards such as BIS 10500 (1991) of water sample. From this study, it was observed that EC exceeded the Permissible limit which impacts of more ion presence in the samples, E.Coli, Coliforms, TBC, Alkalinity, Sodium is higher than the permissible limit in Himayath Sagar and Peerzadiguda. The high content of EC, E.Coli, Coliforms, TBC, Alkalinity in water results in formation of chemical scale or precipitate which would clog piping or form a scale on filter, These parameters were higher in few sampling stations of study area while other parameters were within the permissible limits

Characterization of groundwater aquifers using hydrogeophysical and hydrogeochemical methods in the eastern Nile River area, Khartoum State, Sudan

The primary goals of this research are to detect the spatial variation of the hydrogeological characteristics and evaluate the groundwater quality in the eastern Nile River, Khartoum state, Sudan, using geophysical and hydrochemical methods. Thirteen Vertical electrical soundings (VES), using Schlumberger configuration, were measured along three profiles to characterize the groundwater aquifer. VES findings denoted that the study area comprises two hydraulically connected aquifers. The upper aquifer of sand has an average thickness of 50 m, and the lower aquifer is composed of sandstone of a thickness of up to 300 m. The results of VES inversion were further used to measure aquifer characteristics, including transverse resistance, longitudinal conductance, hydraulic conductivity, and transmissivity. The detected average values of these parameters were 6690 Ωm2, 1.4 Ω−1, 264 m2/d and 4 m/day, respectively. In addition, regression analysis was performed to suggest local relationships for estimating aquifer characteristics within the study area. On the other hand, total longitudinal conductance was used to predict the protective strength of the hydrogeological columns, ranging from 1.7 to 5.8 Ω−1; as a result, the protective capacity of the aquifer ranged from good to very good, suggesting potable water quality. This result was subsequently confirmed by the groundwater quality index (GWQI) model. Eleven physiochemical parameters analyzed for nine boreholes were used in GWQI estimation to assess groundwater quality in the study area. The primary analysis of the hydrochemical parameters indicated that almost all parameters are below permissible limits prescribed by the World Health Organization (WHO). The computed GWQI varies between 34.8 and 148, and the majority of groundwater samples, precisely 55.5%, are good water types, while 22.2% of the samples are in an excellent quality state. This research concluded that the groundwater aquifer in the study area is ideal for groundwater exploitation. However, applying a detailed geophysical and hydrochemical survey is recommended to reduce the uncertainty of the resulting models.

A GIS-based DRASTIC Model for Assessing Groundwater Quality Vulnerability: Case Study of Surat and its Surroundings

A GIS-based DRASTIC Model for Assessing Groundwater Quality Vulnerability: Case Study of Surat and its Surroundings

Groundwater Quality Assessment for Drinking and Irrigation: A Case Study of Talaja, Bhavnagar

Groundwater Quality Assessment for Drinking and Irrigation: A Case Study of Talaja, Bhavnagar

Geospatial approach for assessment of groundwater quality

Geospatial approach for assessment of groundwater quality

Hydrochemistry and groundwater quality assessment around solid waste landfill sites in peri-urban Jaipur, NW India.

Jaipur, the capital city of Rajasthan State in northwestern India, is one of the fastest-growing urban centers in the country. The city and the region around it have documented a substantial drop in the water table due to the over-abstraction of groundwater resources to cater to the increasing water demands of the growing population. Consequently, the entire Jaipurdistrict has been categorized as a "dark zone," prohibiting any further groundwater development activity. Besides its dwindling availability, water quality is also a matter of concern. In places, the water is geogenically contaminated and unsuitable for drinking purposes due to high levels of undesired elements in groundwater, such as high fluoride in the southern part and high chloride in the southwestern part of the district. Groundwater contamination can also occur through several anthropogenic factors, such as industrialization and excessive use of insecticides and pesticides. Water pollution through sewage disposal in open land-fill sites is also an important factor, especially in the growing urban centers. In this study, the water quality evaluation around three landfill sites in the Jaipur district, namely Mathura Das Pura and Langadiyawas (east of the city) and Sewapura (northwest of the city), was carried out. The cation-anion analysis of 45 groundwater samples collected around these sites reveals a wide variation in the abundance of constituent parameters. In a majority of cases, most of the parameters are within acceptable limits prescribed by the national and international agencies (Bureau of Indian Standards and World Health Organization). The fluoride content is more than the prescribed limit of 1.5mg/l in several cases. This could be an intrinsic property of deeper aquifers. The majority of Mathura Das Pura and Langadiyawas samples classify as Na + K - CO3 + HCO3 to Mg - CO3 + HCO3 types in the Piper classification scheme, while a small proportion shows mixed water type characteristics, i.e., with no dominant parameter. Most of the samples have heavy metal abundances within the permissible limits while slightly elevated Cd and Pb levels were observed in some samples. A positive correlation between these two metals can be attributed to a common pollutant, possibly sourced from solid waste. The percent pollution index of Sewapura samples shows lower pollution levels (PPI < 40%) and a dominant chemical weathering trend while the majority of Mathura Das Pura-Langdiyawas samples show a high pollution effect (PPI 40 to 80%). In general, the chemical parameters of Sewapura (relatively new landfill site) samples define a more coherent group while water quality parameters in Mathura Das Pura and Langdiyawas (old landfill sites) samples show a wide variation, unsystematic distribution, and significantly higher than prescribed values for most of the hydrochemical parameters. The study shows that some of the water quality issues may be geogenic, while municipal waste dumping and leachate infiltration have adversely affected the groundwater quality.

Integration of Geochemical Modeling, Multivariate Analysis, and Irrigation Indices for Assessing Groundwater Quality in the Al-Jawf Basin, Yemen

Water quality monitoring is crucial in managing water resources and ensuring their safety for human use and environmental health. In the Al-Jawf Basin, we conducted a study on the Quaternary aquifer, where various techniques were utilized to evaluate, simulate, and predict the groundwater quality (GWQ) for irrigation. These techniques include water quality indices (IWQIs), geochemical modeling, multivariate statistical analysis, geographic information systems (GIS), and adaptive neuro-fuzzy inference systems (ANFIS). Physicochemical analysis was conducted on the collected groundwater samples to determine their composition. The results showed that the order of abundance of ions was Ca2+ &gt; Mg2+ &gt; Na+ &gt; K+ and SO42− &gt; Cl− &gt; HCO3− &gt; NO3−. The assessment of groundwater quality for irrigation based on indices such as Irrigation water quality index (IWQI), sodium adsorption ratio(SAR), sodium percent (Na%), soluble sodium percentage (SSP), potential salinity (PS), and residual sodium carbonate RSC, which revealed moderate-to-severe restrictions in some samples. The Adaptive Neuro-Fuzzy Inference System (ANFIS) model was then used to predict the IWQIs with high accuracy during both the training and testing phases. Overall, these findings provide valuable information for decision-makers in water quality management and can aid in the sustainable development of water resources.

An Integrated Principal Component and Hierarchical Cluster Analysis Approach for Groundwater Quality Assessment in Jazan, Saudi Arabia

Jazan province on Saudi Arabia’s southwesterly Red Sea coast is facing significant challenges in water management related to its arid climate, restricted water resources, and increasing population. A total of 180 groundwater samples were collected and tested for important hydro-chemical parameters used to determine its adaptability for irrigation. The principal components analysis (PCA) was applied to evaluate the consistency/cluster overlapping, agglomeration in the datasets, and to identify the sources of variation between the 11 major ion concentrations (pH, K+, Na+, Mg2+, Ca2+, SO42−, Cl−, HCO3−, NO3−, TDS, and TH). The EC values ranged from excellent to unsuitable, with 10% being excellent to good, 43% permissible, and 47% improper for irrigation. The SAR classification determined that 91.67% of groundwater samples were good to excellent for irrigation, indicating that they are suitable for irrigation with no sodium-related adverse effects. Magnesium hazard values showed that 1.67% of the samples are unsuitable for irrigation, while the remaining 98.33% are suitable. Chloro-alkaline indices signify that most groundwater samples show positive ratios indicating that ion exchange is dominant in the aquifer. The Gibb’s diagram reflects that evaporation, seawater interaction, and water–rock interaction are the foremost processes impacting groundwater quality, besides other regional environmental variables. A strong positive correlation was declared between TDS and Na+, Mg2+, Ca2+, Cl−, SO42− in addition to TH with Mg2+, Ca2+, Cl−, SO42−, TDS, and also Cl− with Na+, Ca2+, Mg2+ were major connections, with correlation coefficients over 0.8 and p &lt; 0.0001. The extracted factor analysis observed that TH, Ca2+, TDS, Cl−, and Mg2+ have high positive factor loading in Factor 1, with around 52% of the total variance. This confirms the roles of evaporation and ion exchange as the major processes that mostly affect groundwater quality, along with very little human impact. The spatial distribution maps of the various water quality indices showed that the majority of unsuitable groundwater samples were falling along the coast where there is overcrowding and a variety of anthropogenic activities and the possible impact of seawater intrusion. The results of the hierarchical cluster analysis agreed with the correlations mentioned in the factor analysis and correlation matrix. As a result, incorporating physicochemical variables into the PCA to assess groundwater quality is a practical and adaptable approach with exceptional abilities and new perspectives. According to the study’s findings, incorporating different techniques to assess groundwater quality is beneficial in understanding the factors that control groundwater quality and can assist officials in effectively controlling groundwater quality and also enhancing the water resources in the study area.

Groundwater Quality Assessment Using Multi-Criteria GIS Modeling in Drylands: A Case Study at El-Farafra Oasis, Egyptian Western Desert

The most critical issue that was the main research interest is its groundwater quality which is vital for public health concerns. Groundwater is a significant worldwide water supply for diverse communities, especially in dryland regions. Groundwater quality assessment in desert systems is largely hindered by the lack of hydrological data and the remote location of desert Oases. This study provides a preliminary understanding of the influences of climate, land usage, and population growth on the groundwater quality in El-Farafra Oasis in the Western Desert in Egypt from 2000 to now. Therefore, the study’s main objective was to determine the extent of change in temporal water quality and the factors causing it. The present study integrates chemical analyses and geospatial modeling better to assess groundwater quality in the study area. A chemical analysis of thirty-one groundwater samples from wells representing each study area was carried out during three time periods (2000, 2010, and 2022). Several chemical properties of groundwater samples gathered from wells in the research area were analyzed. Furthermore, the groundwater quality trend from 2000 to the present was identified using three approaches: Wilcox and Schoeller Diagram in Aq.QA software, interpolation in the ArcGIS software, and Ground Water Quality Index (GWQI). Moreover, the influence of changing land usage on groundwater quality was studied, and it was found that the increase in agriculture and urbanization areas is linked to groundwater quality degradation. The findings revealed that the barren area in 2000, 2010, and 2022 was 371.7, 362.0, and 343.2 km2, respectively, which indicates a substantial decrease of 6.2% within this research timeframe. In contrast, agriculture and human-made structures have expanded by 1.8%. Also, population growth has led to an increase in water consumption as the population has grown at a rate of 7.52% annually from 2000 to 2020. As the climatic condition increases from 2000 to 2022, these changes could extend to the water quality in shallow aquifers with increasing evaporation. Based on the water quality spatial model, it is found that, despite a declining tendency in the rate of precipitation and an expansion in agricultural areas and population growth, the water quality was still appropriate for human and farming consumption in large areas of the study area. The presented approach is applicable to the assessment of groundwater in desert regions in the Middle East area.

Geology and Groundwater Quality Analysis for Clean Water and Irrigation of Sanga-sanga District, Kutai Kartanegara Regency, East Kalimantan Province

The research locations are in two sub-districts, namely Sanga-Sanga District, Samarinda City and Palaran District, Kutai Kartanegara, East Kalimantan Province The research method used in this study is geological mapping, then laboratory analysis. The well water sample data used is 2 sample water which is considered to represent the research area. Geological conditions in the study area there are 3 rock units where the rock units of the oldest are the Sanga-sanga sandstone unit, the Bantuas sandstone unit and alluvial deposits. For geomorphological units, it is divided into 6 forms, namely the eroded hill unit, the remaining hill, the Alluvial Plain, swamp, river body, disposal and mine opening. Based on the results of the piper diagram analysis Groundwater is included in the type of magnesium bicarbonate with carbonate hardness (secondary alkalinity) > 50% groundwater is dominated by alkaline soil (Ca + Mg) and weak acids (CO3 + HCO3), and based on the results of the stiff diagram analysis, the research area is included in the type of calcium carbonate (CaHCO3) and Magnesium Carbonate (MgHCO3). The assessment of groundwater quality for irrigation purposes concluded that the analyzed sample could be used as irrigation water.

Coupling support vector machine and the irrigation water quality index to assess groundwater quality suitability for irrigation practices in the Tana sub-basin, Ethiopia

AbstractLong-term and sustainable agricultural practices can be achieved through monitoring and evaluation of groundwater quality for irrigation operations. However, less attention was given to irrigation water quality in the Tana sub-basin, Ethiopia. The present study is aimed to assess the seasonal and spatial groundwater suitability for irrigation uses. The groundwater quality parameters measured in 40 samples in each dry and wet season were the pH, electrical conductivity (EC), Na+, Ca2+, Mg2+, K+, Fe2+, HCO3-, CO32-, Cl−, and NO3-. The groundwater suitability for irrigation was assessed using the irrigation water quality index (IWQI) and support vector machine (SVM). The results showed high and medium irrigation suitability classes in the dry and wet seasons. The proportion of groundwater samples in the medium irrigation suitability class in the dry and wet seasons, respectively, was 72.5 and 67.5%. The groundwater in the wet season is comparatively more suitable than that in the dry season, which is attributed to the leaching of accumulated salts during the wet season. To avoid a salinity threat, vigilance should be exercised when using groundwater during the dry seasons. The groundwater quality map developed here for irrigation may aid in locating better-quality groundwater sources for irrigation.

Hydrochemical characteristics, quality and health risk assessment of nitrate enriched coastal groundwater in northern China

Groundwater quality is an essential factor restricting regional sustainable development owing to water resource scarcity, especially in coastal regions. Coastal groundwater is affected by natural conditions and strong human activities, and the evolution of water quality is extremely complex. Information on the hydrochemistry evolution and nitrate contamination status of coastal groundwater under the conjunctive effects of natural processes and human activities is a vital requirement for groundwater resource management in coastal regions. Thus, this study integrated traditional hydrochemical analysis approaches, the entropy-weight water quality index (EWQI), and the health risk assessment model to analyze hydrochemical characteristics, quality, and nitrate health risks in a typical coastal region (i.e., southern Laizhou Bay) simultaneously affected by seawater intrusion and anthropogenic activities, as well as to explore the dominant mechanisms controlling groundwater quality. The results indicated that the concentrations of major hydrochemical constituents in groundwater exhibited wide variability. The NO3− concentration varied from 0.59 to 824.80 mg/L; it surpassed the WHO drinking water standard (50 mg/L) at 89.47% of sampling sites. The predominant hydrochemical types of groundwater were SO4•Cl–Ca•Mg and HCO3–Ca•Mg. Governing factors influencing groundwater chemistry were recognized as rock weathering, inverse cation exchange and anthropogenic activities, and nitrate contents were largely controlled by agricultural practices. The computed EWQI showed that 55.26% of groundwater samples possessed EWQI values greater than 57, which is relatively poor-quality groundwater. The poor-quality groundwater was concentrated in the southwestern part of the study area. Non-cancer risks of nitrate in 96.71%, 94.74%, 89.47%, and 89.47% of the groundwater samples were unacceptable for infants, children, teens, and adults, and the spatial distribution of the hazard quotient (HQ) was in accordance with the spatial pattern of nitrate concentration. These findings can guide the exploitation and utilization of groundwater resources and water quality conservation in coastal regions.

A systematic and comparative study of Water Quality Index (WQI) for groundwater quality analysis and assessment.

Water is essential for human survival. Its quality must be maintained to prevent any potential health problems. Pollution and contamination are likely causes of the water quality decline. This may occur if the world's rapidly expanding population and industrial facilities fail to clean their effluent correctly. The Water Quality Index, often known as the WQI, is the indicator most frequently used to characterize surface water quality. This study emphasizes several WQI models that could be of use to us in determining the level of water quality available in the various areas. We have tried to cover multiple essential procedures and their corresponding mathematical counterparts. In this article, we also examine the applications of index models in different types of water bodies, such as lakes, rivers, surface water, and groundwater. The level of contamination in water due to pollution directly affects the overall quality of water. A pollution index is a valuable tool for measuring the level of pollution. Concerning this, we have discussed two approaches, namely, the Overall Index of Pollution and Nemerrow's Pollution Index, which demonstrate the most effective technique to evaluate the water standard. Examining the similarities and differences between these approaches may offer researchers a suitable starting point to delve further into assessing water quality.