Hydrochemical Characteristics Research Articles

Combined cluster and discriminant analysis based on hydrochemical and isotopic evidence: A case study of the Yellow River Delta in China

Groundwater serves as an indispensable resource, fundamental for both sustaining life and underpinning various human endeavors. However, escalating demands, coupled with climate change, have given rise to significant water scarcity in numerous areas, including the Yellow River Delta (YRD) in China. This study aims to characterize the hydrochemical composition and stable isotopes (δ2H and δ18O) of groundwater in YRD and identify spatial clustering patterns using combined Hierarchical Cluster Analysis (HCA) and Discriminant Analysis (DA). Comprehensive analyses were conducted on the major ions (i.e., K+, Na+, Ca2+, Mg2+, Cl-, SO42-, and HCO3-), water quality indicators (i.e., pH, electrical conductivity (EC), and oxidation-reduction potential (ORP)) and isotopic composition of groundwater samples. Applying HCA on a collection of 38 water samples, the study delineated six distinct clusters, each bearing unique hydrochemical characteristics. DA was used to establish a discriminant model, achieving a classification accuracy of 80% for new groundwater samples. The study underscores that there are localized variations in the hydrochemical characteristics of groundwater in YRD, attributed to different geological conditions and anthropogenic influences. Such insights are instrumental in crafting effective strategies for water resource management, environmental conservation, and sustainable development in YRD and other analogous regions confronted with groundwater challenges.

Hydrochemical characteristics and salt intrusion in groundwater of the lower Chao Phraya river basin: Insights from stable isotopes and hydrochemical analysis

Saltwater intrusion is a significant hydrogeological challenge in coastal regions. This study investigates salt intrusion and hydrogeological processes in the Lower Chao Phraya River basin using stable isotopes and hydrochemical analysis. One Hundred groundwater wells sampled from different aquifers were analyzed for major ions spanning from 2010 to 2021, as well as stable isotopes specifically for the samples in the year 2021. The results reveal four distinct groundwater types: Ca(HCO3)2, NaHCO3, NaCl, and CaSO4, based on their predominant cations and anions. Shallow groundwater, which represents the discharge zone affected by salt intrusion, halite dissolution, and cation exchange reactions, exhibits a significant concentration of NaCl. Water-rock interactions play a crucial role in shaping groundwater chemistry, with carbonate dissolution and precipitation dominating the Ca(HCO3)2 type and silicate weathering influencing the CaSO4 type. The NaHCO3 type is associated with ion exchange and seawater intrusion. Silicate and carbonate rock weathering are the dominant processes in the region. Stable isotope analysis indicates that groundwater recharge primarily comes from rainfall and surface water, with limited contributions from deep sources. Overall, this study provides valuable insights into the hydrochemical characteristics and complex water-rock interactions within the groundwater system of the Chao Phraya River basin. As a result, it holds significant potential for informing effective groundwater management practices and facilitating resource planning in the region. Furthermore, the findings and methodologies presented here offer valuable lessons for addressing saltwater intrusion and hydrogeological challenges in other coastal regions worldwide.

Interpretation of Diverse Physico-Chemical Water Quality Parameters of Jaipur (Rajasthan) Sampling Sites for Plantation, Irrigation and Fluorosis Concern

The present study is aimed to evaluate the hydro chemical characteristics and quality of groundwater. Groundwater samples were collected from selected sampling sites like Shivdaspura (S1), Mansarovar (S2), Tonk Phatak (S3) and Chand pole (S4) in Jaipur District, Rajasthan and analyzed for major physico-chemical parameters. Such as Colour vis, Chemical Oxygen Demand (COD), Bio-Chemical Oxygen Demand (BOD), Lead, Cadmium, Chloride, Fluoride, Dissolved Oxygen (DO), Total Hardness (TH), Total Alkalinity, Total Solids, Total Dissolve Solids (TDS), Total Suspended Solids, Taste and Odour, Turbidity, Electrical Conductivity (EC), Magnesium, pH, Nitrate, Calcium, Sulphate Were analysed fora period from 29March 2021 to 09 December 2021. Fluoride content in the water samples of study area varied from 0.57mg/l to 7.97mg/l. Due to the higher fluoride levels in drinking water of Shivdaspura area showing dental fluorosis in which the teeth of the children were damaged and characterized by brown and black stains.

Hydrochemical Characteristics and Controlling Factors of Shallow and Deep Groundwater in the Heilongdong Spring Basin, Northern China

Heilongdong Spring Basin (HSB) is located in a semi-arid region in northern China. In the past few decades, it has been influenced by anthropogenic activities. Currently, there is a lack of information about the impact on the hydrogeochemistry and groundwater quality of different aquifers. To address this concern, the present study used conventional hydrochemical diagrams, stable isotope analysis and multivariate statistical techniques to analyze hydrochemical characteristics and controlling factors of shallow and deep groundwater in the study area. The results showed that all groundwater samples were weakly alkaline. The shallow groundwater (SGW) was mainly composed of SO4-Ca and SO4·HCO3-Ca·Mg water types with high TDS values. However, the predominant water types of deep groundwater (DGW) were HCO3-Ca·Mg and HCO3·SO4-Ca·Mg types with relatively low TDS. The large majority of shallow groundwater had poor water quality, which was influenced by natural factors and anthropogenic activities, characterized by high concentrations of SO42−, NO3−, and Cl−. In contrast, the overall water quality of deep groundwater was good, mainly controlled by the natural background. Nonetheless, a few karst groundwater samples of DGW in runoff areas exhibited close hydraulic connections with SGW samples and presented contamination to a certain degree. Our research results provide a scientific basis for the utilization and protection of groundwater in different aquifers in northern China.

Hydrochemical Characterization and Quality Assessment of Groundwater in the Southern Plain of Hebei Province, China

The purpose of this research was to understand the hydrogeochemical characteristics and assess the quality of phreatic and confined groundwater in southern Hebei Province. A total of 107 groundwater samples were collected, representing different aquifer conditions over the study area. Multivariate statistical analysis, hydrochemical maps, ionic ratio coefficients, geographic information system (GIS) and geochemical simulation were comprehensively and systematically used to reveal the hydrochemical characteristics of groundwater and its controlling mechanism. The results revealed that both phreatic (pH = 7.02–9.08) and confined groundwater (pH = 7.00–10.60) were slightly alkaline. The hydrochemical types were mainly present as the HCO3-Ca-Mg type in the western premontane area and mixed Ca-Mg-SO4-Cl and Na-Cl-SO4 types in the eastern plains. The hydrochemical composition was dominated by water–rock interactions of natural processes, including silicate weathering, dissolution of sulfate minerals (gypsum, anhydrite), and cation-exchange adsorption. Anthropogenic activities were the main factor causing NO3− content in some groundwater samples to exceed the geochemical baseline. The hydrogeochemistry of groundwater in different aquifers was significantly varied. The average contents of TH, TDS, Na+, Ca2+, Mg2+, Cl− and SO42− in phreatic aquifers were significantly higher than those in confined aquifers. The Entropy Weighted Water Quality Index (EWQI) results revealed that 17.78% of phreatic and 50% of confined water samples were meeting the purpose of drinking water. The groundwater samples with EWQI values exceeding 100 were mainly situated in the Handan urban area and the eastern region of Xingtai City, which should be avoided for direct utilization and needs to be improved through protection and management measures, to enhance the quality of groundwater. Correlation analysis showed that groundwater quality was significantly dominated by TH, TDS, Na+, Mg2+, Cl− and SO42− concentrations.

Hydrochemical Characteristics and Evolution of Underground Brine in Lop Nur of Xinjiang, Northwestern China

AbstractLop Nur is located in the eastmost end of the Tarim Basin in Xinjiang, Northwestern China. This study covers the hydrochemical characteristics and evolution of underground brine in Lop Nur based on analytical data of 429 water samples (mainly brine). It is found that in the NE‐SW direction, from the periphery to the Luobei sub‐depression, while the hydrochemical type varies from the sodium sulfate subtype (S) to the magnesium sulfate subtype (M), the corresponding brine in the phase diagram transfers from the thenardite phase (Then) area, through the bloedite phase (Blo), epsomite phase (Eps), picromerite phase (Picro), and finally to the sylvite phase (Syl) area. As for the evolution degree, the sequence is the periphery < Luobei horizontally and the overlying glauberite brine < the underlying clastic brine vertically. It is concluded that the oxygen and hydrogen isotopic compositions of the brine have been evidently affected by evaporation and altitude effect, as well as the changes in local water circulation in recent years. Boron and chloride isotopic compositions show that the glauberite brine is formed under more arid conditions than the clastic one. The strontium isotopic composition indicates that the Lop Nur brine mainly originates from surface water; however, deep recharge may also be involved in the evolution of brine according to previous noble gas study. It is confirmed that the brine in Lop Nur has become enriched with potassium before halite precipitates over the full course of the salt lake evolution. Based on chemical compositions of brine from Drillhole LDK01 and former lithological studies, the evolution of the salt lake is divided into three stages and it is inferred that the brine in Lop Nur may have undergone at least two significant concentration‐dilution periods.

Hydrochemistry of Lake Onega According to the Results of Research in 2022

The article presents the results of a study of the hydrochemical characteristics of the water of Lake Onega in 2022. Some of the hydrochemical parameters were determined by in situ probes, some later in the laboratory. Most samples are characterized by a high degree of oxygen saturation, a high pH level, low concentrations of biogenic elements and dissolved forms of heavy metal ions, but a sufficiently high content of petroleum hydrocarbons. At the same time, the areas of the lake where the hydrochemical characteristics differ in originality are marked. The high vulnerability of the lake ecosystem in combination with anthropogenic load, which may increase in the future, ensure the relevance of monitoring the state of the waters of Lake Onega.

Hydrochemical characteristics and water quality assessment of natural water in the South China Mountains: the case in Lianzhou.

South China Mountain Region has a well-developed water system with the most abundant water in China. Untreated natural water is the main source of drinking water for the local people. This study aimed to investigate the hydrochemical characteristics and trace element concentrations of natural water in the mountainous regions of South China. In this study, 116 water samples were collected. Traditional hydrochemical methods, water quality index (WQI), hazard index (HI), and nutrient speciation of trace elements (NSTE) were used for analysis. In general, the hydrochemical type was mainly Ca-HCO3- type. The hydrochemical characteristics were mainly influenced by the weathering of calcite and silicate rocks. Overall total dissolved solids (TDS) were low, indicating mainly soft and very soft water. The water that met the standards for mineral water had an average concentration of 59.69mg/L for Sr (strontium) and an average concentration of 0.46mg/L for H2SiO3 (silicic acid). Although the water quality index (WQI) indicated that 91.3% of the water samples in the study area were of good quality (WQI < 25), 2.58% of the water samples had significant non-carcinogenic risk (HI > 1) due to the high As and Pb concentrations. The water in the study area contributed significantly to human intake of Sr, Cr, and V, accounting for 8.4, 8.3, and 7.7% of the required daily intake for adults, respectively. It is recommended that a comprehensive water quality evaluation system be constructed to ensure that mountain water is managed for development and safe to drink.

Hydrochemical Characteristics and Self-Purification Potential of Iyiechu Stream in Okigwe Area, Southeastern Nigeria

Iyiechu stream is a small tropical urban stream that receives both domestic and industrial wastes. The self-purification potential of the stream was determined by evaluating its deoxygenation and reaeration rate coefficients. The methods of study used include dissolved oxygen (DO) measurements, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) tests as well as measurements of hydrological parameters. Deoxygenation rate of 0.20 to 0.42/day were obtained indicating very swift depletion of oxygen in the stream probably as a result of domestic sewage input. The reaeration rate coefficients ranged from 0.01 to 0.84 day and these values suggest deep and slow moving streams. The measured DO values are quite low, indicating high deoxygenation reaction in the stream and minimal dissolved oxygen contribution from other sources such as algal photosynthesis. Spatially, about 66.66% of the stream is dominated by deoxygenation reaction. The chemical oxygen demand ranged from 20 to 40 mg/l. These values are relatively high and show that the process may be partly responsible for the low dissolved oxygen levels in the stream. However, the stream is capable of re-attaining its optimum dissolved oxygen level within a flow time of 0.84 day (20hrs 16minutes) in the rainy season. Thus, a flow time much greater than 0.84 day (20hrs 16minutes) would be required during the dry season. These flow times suggest that the stream has poor self-purification potential.

Transport of pollutants in groundwater of domestic waste landfills in karst regions and its engineering control technologies

Domestic waste produces leachate with a high concentration of pollutants in the landfill process due to biochemical degradation stages like compaction and fermentation. A large number of cases show that anti-seepage membranes widely used in refuse landfills tend to rupture under long-term tension and corrosion, causing leachate to enter the groundwater system and pollute the environment. To reveal the phenomenon of groundwater contamination in refuse landfills, typical domestic waste landfills in karst regions were examined, on the basis of a summary of hydrogeological conditions and hydrochemical characteristics, a three-dimensional groundwater flow model and solute transport model were constructed to analyze the pattern of pollutant diffusion, and its controlling factors, under the current conditions and massive rupture of anti-seepage membrane. The results show that with a minor rupture of the anti-seepage membrane, the area of the low pollution region increases first and then decreases while that of the slight pollution region continuously increases; When a massive rupture of the anti-seepage membrane appears, the ranges of heavy pollution region and total pollution regions continue to grow; Pollutant migrates along the same direction as the groundwater flow and diffuse from high concentration region to low concentration regions under the differential concentration effect. Based on the temporal-spatial distribution characteristics of groundwater pollutants, two engineering control schemes, namely, curtain grouting blocking and group well pumping, were established. A comparison of the two control schemes shows that group well pumping stably maintains water quality safety over the long term, pollutants overflow from both sides of the curtain after they have accumulated to a certain point of concentration, causing damage to the groundwater environment in the conservation area.

[Hydrochemical Characteristics and Controlling Factors in Wudu River Basin of Guizhou Province].

TheWudu River is a typical mining-type watershed in the karst mountainous area of western Guizhou Province. Based on the collection of the main stream, tributaries, spring water, and mine water samples in Wudu River Basin, the hydrochemical characteristics and control factors of Wudu River Basin were studied using Gibbs diagram, Piper diagram, and mathematical statistics analysis, and the solute contribution rate of different sources was calculated. The results revealed that the pH value of the water in the Wudu River Basin ranged from 7.87 to 8.52, with an average of 8.14. The TDS values ranged from 135 to 243 mg·L-1, with an average of 191.7 mg·L-1. The major cations in natural river and spring water were Ca2+ and Mg2+, the major anion was HCO3-, and the hydrochemical type was HCO3-Ca. However, owing to the influence of mining activities, the major cations in some tributaries were Ca2+ and Na+, and the hydrochemical types transitioned to HCO3·SO4-Ca and HCO3·SO4-Ca·Na. The ion components of river water in Wudu River Basin were affected by mine water discharge and cation exchange, carbonate rock weathering, silicate rock weathering, and agricultural fertilization. The high concentration of SO42- and Na+in mine water was the primary source of SO42- and Na+in the tributaries of the Wudu River. The method for calculating chemical material balance showed that the contribution rate of carbonate rock weathering ranged from 44.12% to 86.92%, with an average of 74.32%. The contribution rate of mining activities ranged from 3.28% to 37.07%, with an average of 11.61%. Carbonate rock weathering was the main controlling factor of hydrochemical components in the Wudu River Basin; meanwhile, mining activities also had a certain impact on river water chemistry but they showed spatial heterogeneity. The average contribution rates of atmospheric precipitation, silicate rock weathering, agricultural activities, and domestic sewage were 3.75%, 4.67%, 2.85%, and 2.81%, respectively, which had a limited impact on the hydrochemical components of the basin.

Hydrochemical and dual-isotope approach to the identification of denitrification in arable field drainage in the Wensum catchment, eastern England

The global pool of reactive nitrogen has doubled in the last century in response to the need to increase food production with the consequent increase in fertiliser-derived reactive nitrogen detrimentally affecting aquatic ecosystems. This study investigates the spatial distribution and significance of denitrification in the lowland, agriculturally-impacted River Wensum catchment in eastern England as a natural attenuation process. To investigate the evidence for denitrification, the hydrochemical characteristics and dual stable isotope composition of nitrate (15N and 18O) were measured over a 15-month period, 2015–2017, in 63 samples of field drainage in predominantly clay loam and sandy clay loam soils under mainly arable cultivation. Microbially-mediated denitrification in field drainage was indicated by the gradient of the linear regression of 15NNO3 and 18ONO3 compositions with a value of 0.58. Dual fractionation of the nitrate isotopes yielded enrichment factors for δ15NNO3 (−4.52‰) and δ18ONO3, (−4.51‰) within the reported ranges for denitrification in aquatic studies. Soil type influenced denitrification, with a positive relationship between percentage clay and δ15NNO3 and δ18ONO3 values. The same relationship was observed for denitrification rates calculated via a simple mass balance approach, which ranged from 11.0 to 26.3 kg N ha−1 and accounted for 30–73% of the leached soil nitrogen. Higher denitrification rates were recorded in drainage areas with a greater soil clay content (>20% by weight). Comparing calculated dentification rates for individual drain areas with median δ15NNO3 values of drain samples demonstrated that an isotopic enrichment of +1‰ is associated with a denitrification rate of 2.6 kg N ha−1. In conclusion, sustainable agricultural practices that maintain natural attenuation processes such as denitrification, for example by preserving and increasing the soil organic carbon content, are desirable to improve overall soil health to support ecosystem services that reduce nitrate pollution.

Hydrochemical characteristics and the impact of human activities on groundwater in a semi-arid plain: a case study of western Jilin Province, Northeast China.

Groundwater is important for human survival and development, particularly in arid and semi-arid regions. This study aimed to analyze the hydrochemical characteristics, influencing factors, and the impact of human activities on groundwater in the semi-arid plains of western Jilin Province, northwest China. The study collected 88 and 151 phreatic and confined water samples, respectively, which were analyzed for 13 water quality indicators using statistical and graphical methods. In order to investigate the impact of anthropogenic activities on water quality and health risks, the improved combined weighted water quality index (ICWQI) based on the entropy weight, criteria importance though inter-criteria correlation (CRITIC), the coefficient of difference method, subjective weight based on quality grading criteria, and the water quality index (WQI) were proposed to evaluate the water quality of the study area. Meanwhile, the human health risk assessment (HHRA) model was used to assess the risks of nitrate to the health of humans in different ages and sex categories. The results indicated that the groundwater in the study area was weakly alkaline and the main hydrochemical types in the phreatic and confined water were HCO3-·Ca-Mg and HCO3--Na. Rock weathering was the dominant process responsible for the generation of groundwater ions, the ions in groundwater primarily originate from the dissolution of halite, gypsum, and feldspar, while dolomitization promotes an increase in Mg2+. Human activities lead to an increase in NO3- in groundwater and have an impact on water quality and human health risks. The ICWQI method was found to yield more precise and rational assessments of water quality. Groundwater quality is primarily affected by nitrate ions. The areas in which groundwater nitrate posed a higher risk to human health were found to be mainly in the saline-alkali lands of Qian'an, Tongyu, and Zhenlai. Fertilizers, pesticides, and livestock farming activities contribute to the pollution of surface water. This surface contamination then infiltrates abandoned confined wells, leading to contamination of the confined aquifers. This study can improve the understanding of groundwater hydrochemical characteristics and the impact of human activities on groundwater in the study area. This study can also contribute to the study of groundwater in semi-arid regions.

The current state of the Southern Bug River mouth ecosystem

The article considers the pre-war conditions main components of the Southern Bug mouth ecosystem. The results of sediments samples study have shown transformation of lagoonal accumulation, appearance of reducing condition spots in sediments, presence of exceeding MAP for lead. An estuarine water analysis given an idea about hydrochemical features mouth section of river, namely: high concentration of suspended solids – on an average 11,4 mg/dm3; increasable concentration BOD5 – an indicator of easily oxidized organic substances content; periodic significant exceeding MAC of ammonium and nitrite nitrogen. Hydrobiological changes primarily concern a decrease in primary productivity due to a decline in phytoplankton biodiversity; there was also a reduction of zooplankton. The current state of the Southern Bug River mouth ecosystem is formed predominantly under the periodic dredging of shipping channels followed by the formation silt dumps. The post-war revitalization of the Southern Bug estuary ecosystem should include measures to mitigate the negative effects of anthropogenic activity especially the consequences of hydraulic engineering works.

Isotope and hydrochemical characteristics of thermal waters along the active fault zone (Erzin-Hatay/Turkey) and their geothermal potential

Isotope and hydrochemical characteristics of thermal waters along the active fault zone (Erzin-Hatay/Turkey) and their geothermal potential

Study of the Hydrochemical Characterization of Drinking Water from the Aquifer of the Town of Guitté at Hadjer Lamis

A hydrogeological study was carried out in and around Guitté. This study aims to contribute to the understanding of the hydrochemical parameters of the waters of the Guitté aquifer. with a view to the sound and sustainable management of available water resources. A field mission to measure and sample borehole water was carried out from March 26 to 28. 2023 in and around Guitté. Physicochemical analyses were carried out on 28 water samples from human-driven pumps). The study showed that the groundwater exploited in this area has an average temperature of 29°C. Overall. the pH values measured in the sampled waters are not very heterogeneous and are around neutral. Electrical conductivity values are highly heterogeneous. Two types of chemical facies have been identified in Guitté groundwater: sodium or potassium bicarbonate facies. and calcium and magnesium bicarbonate facies. The overall quality of the groundwater obtained for consumption is 60.71% rated as good. 39.28% as poor. The origin of the mineralization could be linked. on the one hand. to water/rock contact. due to the dissolution of natron. limestone. gypsum and thenardite and on the other hand. to the phenomenon of intense evaporation.

Оценка экологического состояния реки Сояна в зоне возможного воздействия алмазоносного месторождения

The article presents the results of a comprehensive study of the Soyana River for the first time. The characteristics of hydrological and hydrochemical parameters were obtained while observations in July 2020 and March 2021. Changes in the hydrogen index (pH), mineralization, and the content of dissolved oxygen and biogenic elements in water, as well as petroleum hydrocarbons in water and bottom sediments were studied using generally accepted in hydrochemical practice methods. The data obtained were evaluated for compliance with the regulatory requirements for the river water quality. According to the chemical composition, the Soyana River water belongs to the hydrocarbonate class of small and medium mineralization (164–296 mg/L), weakly acidic and slightly alkaline type (pH 6.0–8.2). The data obtained allow us to conclude that there is no noticeable anthropogenic impact on the considered watercourse. The petroleum hydrocarbons content in water and bottom sediments was below maximum permissible concentrations. In river water it was below 0.010 mg/L, in bottom sediments – in the range from 0.2 to 3.2 mg/kg. The maximum content of petroleum hydrocarbons in soils was recorded in the lower course of the river, where bottom sediments are presented in the form of silty sand. The interannual variability of hydrological and hydrochemical characteristics in the direction from the source to the mouth of the river is estimated. The relationship and regularity of their distribution was specified. The data obtained can serve as background data for assessing the negative impact in case of anthropogenic load on the river basin.

Research Progress of Drinking Water and Trace Elements in KBD Area

Kaschin-beck disease (KBD) is an endemic, chronic, and deformable osteochondral disease characterized by multiple degenerations and deep cell necrosis of epiphysis, epiphysis, and articular cartilage. The disease mainly affects children and adolescents aged 5-15, is concentrated in northeast and southwest China, involving 15 provinces, and extends into southeastern Siberia and North Korea. Although the etiology and pathogenesis of KBD are still not very clear, in recent years, more breakthroughs have been made in the supplement and update of its biogeochemical theory, especially in the analysis of hydrochemical characteristics and the study of the role of selenium and iodine in the pathogenic factors of KBD. Therefore, the present research results on the environmental geographical factors of Kashin-beck disease are reviewed in this paper.

Hydrochemical Characteristics and Driving Factors of Surface Water in Nenensangcuo, Eastern Margin of Qinghai–Tibet Plateau, China

Hydrochemical Characteristics and Driving Factors of Surface Water in Nenensangcuo, Eastern Margin of Qinghai–Tibet Plateau, China

Identifying the hydrochemical features, driving factors, and associated human health risks of high-fluoride groundwater in a typical Yellow River floodplain, North China.

Fluoride enrichment (> 1.5mg/L) in groundwater has become a global threat, particularly given the hazards to human health. This study collected 58 unconfined groundwater samples from Fengpei Plain in June 2022 for hydrochemical and stable isotope analyses combined with multiple methods to explore sources, influencing factors, and potential health hazards of groundwater F-. The results showed that groundwater F- concentration ranged from 0.08 to 8.14mg/L, with an average of 1.91mg/L; over 41.4% of them exceeded the acceptable level of 1.5mg/L prescribed by the World Health Organization (WHO). The dominant hydrochemical facies changed from Ca·Mg-HCO3 and Ca·Mg-SO4·Cl type in low-F- groundwater to Na-HCO3 and Na-SO4·Cl water types in high-F- groundwater. The Self-Organizing Map (SOM) and ionic correlation analysis indicated that F- is positively correlated to pH, EC, Na+, K+, SO42-, and TDS, but negatively to Ca2+ and δ18O. Groundwater F- accumulation was primarily driven by F--bearing minerals dissolution such as fluorite. Simultaneously, the carbonates precipitation, positive cation exchange processes, and salt effect were conducive to groundwater F- enrichment. However, competitive adsorption between OH-/HCO3- and F-, evaporation, and anthropogenic activities only had a weak effect on the F- enrichment in groundwater. The hazard quotient (HQ) assessment results show that 67.2% of groundwater samples pose a non-carcinogenic risk (HQ > 1) for infants, followed by 53.4% for children, 32.8% for females, and 25.9% for males. The Monte Carlo simulation results agreed with those of the deterministic model that minors are more susceptible than adults. These findings are vital to providing insights into the geochemical behavior, driving factors, and drinking water safety of high-F- groundwater worldwide.