Articoli di riviste: "Hydrochemical modeling"

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Dzombak, David A., and M. Ashraf Ali. "Hydrochemical Modeling of Metal Fate and Transport in Freshwater Environments." Water Quality Research Journal 28, no. 1 (February 1, 1993): 7–50. http://dx.doi.org/10.2166/wqrj.1993.003.

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Abstract During the last decade there has been growing interest in the development of hydrochemical models (coupled transport-chemistry-biology models) for better understanding and, eventually, for predicting the fate and transport of metals in freshwater environments. While there has been much discussion of such models and their submodels, and detailed examinations of the mechanistic descriptions and mathematics involved in their formulation, there has been relatively little attention focused on how well they perform in describing field data. This paper provides a look at the state-of-the art in hydrochemical modeling of metal fate and transport in groundwater, riverine and lacustrine systems through review of reported model validation attempts. Focus is on those models that have been applied to describe field data; the degree of success achieved and related factors are examined. Key observations drawn from our review of available hydrochemical models and attempted applications to field data are as follows: (1) most existing models consider steady one-dimensional flow only; (2) most existing models consider only one or a few chemical reaction mechanisms, with sorption-desorption being the most common; (3) local equilibrium is assumed in most models, though kinetic formulations for some chemical processes have been incorporated in some models; and (4) interaction of metals with biota have been considered in only a few models and in a very simplified manner. The most advanced hydrochemical models for metal fate and transport appear to be those for groundwater systems, followed in order by those for rivers and lakes. From a larger perspective, however, hydrochemical models for metals are still at an early stage of development for all freshwater environments.

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Liu, Yi, Mingqian Li, Ying Zhang, Xiaofang Wu, and Chaoyu Zhang. "Analysis of the Hydrogeochemical Characteristics and Origins of Groundwater in the Changbai Mountain Region via Inverse Hydrogeochemical Modeling and Unsupervised Machine Learning." Water 16, no. 13 (June 28, 2024): 1853. http://dx.doi.org/10.3390/w16131853.

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This study employed hydrochemical data, traditional hydrogeochemical methods, inverse hydrogeochemical modeling, and unsupervised machine learning techniques to explore the hydrogeochemical traits and origins of groundwater in the Changbai Mountain region. (1) Findings reveal that predominant hydrochemical types include HCO3−Ca·Mg, HCO3−Ca·Na·Mg, HCO3−Mg·Na, and HCO3−Na·Mg. The average metasilicic acid content was found to be at 49.13 mg/L. (2) Rock weathering mechanisms, particularly silicate mineral weathering, primarily shape groundwater chemistry, followed by carbonate dissolution. (3) Water‒rock interactions involve volcanic mineral dissolution and cation exchange adsorption. Inverse hydrogeochemical modeling, alongside analysis of the widespread volcanic lithology, underscores the complexity of groundwater reactions, influenced not only by water‒rock interactions but also by evaporation and precipitation. (4) Unsupervised machine learning, integrating SOM, PCA, and K-means techniques, elucidates hydrochemical types. SOM component maps reveal a close combination of various hydrochemical components. Principal component analysis (PCA) identifies the first principal component (PC1), explaining 48.15% of the variance. The second (PC2) and third (PC3) principal components, explain 13.2% and 10.8% of the variance, respectively. K clustering categorized samples into three main clusters: one less influenced by basaltic geological processes, another showing strong igneous rock weathering characteristics, and the third affected by other geological processes or anthropogenic factors.

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Myagkov, Sergey. "THREE-DIMENSIONAL (3-D) SPATIAL-TEMPORAL ANALYSIS OF THE HYDROCHEMICAL MODE OF THE SYRDARIA RIVER." Journal of Science and Innovative Development 3, no. 2 (May 29, 2020): 83–88. http://dx.doi.org/10.36522/2181-9637-2020-2-10.

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The analysis of the hydrochemical regime of the rivers feeding the irrigated territories of agricultural land in the river basin is essential to develop scientifically based recommendations on the rational use of water and land resources. Anthropogenic influence on water and land resources in the basins of the rivers inevitably affects the change of surface water quality. A new method is proposed for analyzing the hydrochemical regime of the rivers based on three-dimensional (3-D) modeling of the Spatio-temporal distribution of water mineralization along the length of the main river. This method allows to analyze the flow of pollutants into the river, identify the main causes of pollution, and the formation of the hydrochemical regime of rivers.

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Tunakova, Yulia, Svetlana Novikova, Vsevolod Valiev, Evgenia Baibakova, and Ksenia Novikova. "The Use of Neural Network Modeling Methods to Determine Regional Threshold Values of Hydrochemical Indicators in the Environmental Monitoring System of Waterbodies." Sensors 23, no. 13 (July 5, 2023): 6160. http://dx.doi.org/10.3390/s23136160.

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The regulation of the anthropogenic load on waterbodies is carried out based on water quality standards that are determined using the threshold values of hydrochemical indicators. These applied standards should be defined both geographically and differentially, taking into account the regional specifics of the formation of surface water compositions. However, there is currently no unified approach to defining these regional standards. It is, therefore. appropriate to develop regional water quality standards utilizing modern technologies for the mathematical purpose of methods analysis using both experimental data sources and information system technologies. As suggested by the use of sets of chemical analysis and neural network cluster analysis, both methods of analysis and an expert assessment could identify surface water types as well as define the official regional threshold values of hydrochemical system indicators, to improve the adequacy of assessments and ensure the mathematical justification of developed standards. The process for testing the proposed approach was carried out, using the surface water resource objects in the territory of the Republic of Tatarstan as our example, in addition to using the results of long-term systematic measurements of informative hydrochemical indicators. In the first stage, typing was performed on surface waters using the neural network clustering method. Clustering was performed based on sets of determined hydrochemical parameters in Kohonen’s self-organizing neural network. To assess the uniformity of data, groups in each of the selected clusters were represented by specialists in this subject area’s region. To determine the regional threshold values of hydrochemical indicators, statistical data for the corresponding clusters were calculated, and the ranges of these values were used. The results of testing this proposed approach allowed us to recommend it for identifying surface water types, as well as to define the threshold values of hydrochemical indicators in the territory of any region with different surface water compositions.

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Wei, Zhonglin, Yuan Ji, Huiming Fang, Lujia Yu, and Donglin Dong. "Rapid Source Identification of Mine Water Inrush Using Spectral Data Combined with BA-RBF Modeling." Water 17, no. 6 (March 10, 2025): 790. https://doi.org/10.3390/w17060790.

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Coal mine safety is vital not only for maintaining production operations but also for ensuring the industry’s sustainable development. The threat posed by mine water hazards is especially severe, growing more critical as mining activities become more intense and reach greater depths. Currently, common methods for identifying water sources mainly depend on hydrochemical data, supplemented by analyses of water level and temperature changes. However, due to constraints in cost, time, and the complexity of mining conditions, there is still significant potential for enhancing water source identification techniques. To advance water source identification, this study introduces a novel approach that uses a spectrophotometer to gather spectral data from water sources. These data are then integrated with a bat algorithm (BA)-optimized radial basis function (RBF) neural network to develop a model for identifying water inrush sources. At Baode Coal Mine in China, 105 water samples from four different sources were collected and analyzed using spectral data. The baseline was corrected using the second derivative technique to ensure the data’s integrity. Additionally, 54 sets of historical hydrochemical data were collected for comparison with the spectral data-based model. Theoretical analysis and experimental results show that both hydrochemical and spectral data are effective for identifying water inrush sources. The hydrochemical data model achieved an accuracy of about 90%, whereas the model based on spectral data reached an average accuracy of 95%. Among the tested models: RBF, GA-RBF, PSO-RBF, BA-RBF, and the BA-RBF model demonstrated superior performance, providing the most rapid and accurate identification of water inrush.

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Пичугина, Анна Игоревна, and Ирина Геннадьевна Критова. "MODELING OF HYDROCHEMICAL OXIDATION OF HEAZLEWOODITE WITH NITRIC ACID." Вестник Тверского государственного университета. Серия: Химия, no. 3(41) (November 10, 2020): 65–72. http://dx.doi.org/10.26456/vtchem2020.3.7.

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В работе представлены результаты математического моделирования окислительного растворения хизлевудита в растворах азотной кислоты в условиях равнодоступной поверхности вращающегося диска с применением метода полного факторного эксперимента. Получены и проанализированы зависимости скорости процесса гидрохимического окисления сульфида никеля (W, моль/смс) от продолжительности взаимодействия (τ, с), влияния концентрации азотной кислоты (С, моль/дм), частоты вращения диска (ω, с) и температуры (Т, К). Определены основные кинетические параметры: константа скорости и эффективная энергия активации процесса. Установлены режимы взаимодействия хизлевудита с азотной кислотой, выявлены вероятные лимитирующие стадии взаимодействия. The paper presents the results of mathematical modeling of the oxidative dissolution of hizlewudite in solutions of nitric acid using the rotating disk method and the factor experimental design. The dependences of specific speed of dissolution of sulfide of nickel Nickel sulfide (W, mol/cmc) on the duration of interaction (τ, s), the influence of nitric acid concentration (C, mol/dm), frequencies of rotation disk (ω, s) and temperatures (T, K) were obtained and analyzed. The main kinetic parameters are determined: the rate constant and the activation energy of the process. Established modes of interaction heazlewoodite with nitric acid, identified probable limiting stage of the interaction.

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Yang, Nuan, Guangcai Wang, Zheming Shi, Dan Zhao, Wanjun Jiang, Liang Guo, Fu Liao, and Pengpeng Zhou. "Application of Multiple Approaches to Investigate the Hydrochemistry Evolution of Groundwater in an Arid Region: Nomhon, Northwestern China." Water 10, no. 11 (November 16, 2018): 1667. http://dx.doi.org/10.3390/w10111667.

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Groundwater is a critical water resource for human survival and economic development in arid and semi-arid areas. It is crucial to understand the groundwater circulation and hydrochemical evolution for sustainable management and utilization of groundwater resources in those areas. To this end, an investigation of the hydrochemical characteristics of surface water and groundwater was conducted in Nomhon, an arid area located in the Qaidam Basin, northwest China, by using hydrochemical (major and trace elements) and stable isotopes (δD and δ18O) approaches. Stable isotopes and ion ratios were analyzed to determine the recharge sources, hydrochemistry characteristics, and major hydrogeochemical processes. Meanwhile, inverse geochemistry modeling was applied to quantitatively determine the mass transfer of hydrogeochemical processes. The results showed that groundwater in the study area is mainly recharged by atmospheric precipitation in mountainous areas, and the groundwater in the center of basin might originate from ancient water in cold and humid environments. Along the groundwater flow path, the TDS of groundwater increased gradually from fresh to salty (ranging from 462.50 to 19,604.40 mg/L), and the hydrochemical type changed from Cl·HCO3–Na·Mg·Ca to Cl–Na. Groundwater chemical composition and mass balance modeling results indicated that from alluvial fan to lacustrine plain, the main hydrogeochemical processes changed from the dissolution of halite and albite and the precipitation of dolomite and kaolinite to the dissolution of halite and gypsum, precipitation of calcite, redox (SO42− reduction), and cation exchange. This study would be helpful for water resources management in this area and other similar areas.

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Yakhno, Oleg, Ihor Hnativ, and Roman Hnativ. "Influence of cavitation processes on river water purification of mountain streams." Mechanics and Advanced Technologies 6, no. 1 (May 31, 2022): 62–69. http://dx.doi.org/10.20535/2521-1943.2022.6.1.254613.

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Problems: The article considers the study of the influence of cavitation phenomena in hydrodynamically active areas of mountain rivers on the processes of natural self-purification of water. The paper considers the experimental results of determining the change in seasonal indicators of the hydrochemical composition of surface waters in the Stryi river basin. Objective: to determine the impact of hydrodynamically active areas (HAA) of mountain rivers on the processes of natural self-purification and to develop methods of laboratory modeling of these areas to determine the hydrochemical parameters of river waters. Methods of implementation: Research of ecological and hydrochemical factors of chemical composition of natural waters of the Stryi river basin combines basin and landscape-geochemical approaches, which allows to integrate various natural and anthropogenic influences, to identify the most important parameters for their detailed analysis. The combination of these approaches made it possible to improve the method of ecological analysis of the area of the Stryi river basin, which allows to spatially differentiate and hydrochemically integrate the factors of formation of the chemical composition of natural waters. Results: It is stated that microbiological safety of water is a special problem, because even water from underground sources may contain single cells of pathogenic microorganisms, but the main threat is water re-contaminated with microbes in case of leaks in the water supply network. Conclusions: Analysis of the results of studies of the impact of self-cleaning processes in the river Stryi on the quality of water intake in Stryi showed that there are currently no negative effects of river waters of the river Stryi on groundwater deposits. The quality of river water is satisfactory for its use in domestic and drinking water supply and for recreational purposes.

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Feng, Shaoyi, Zhongpei Liu, Yuping Han, Lu Wang, Zhipeng Hu, and Mingkun Qi. "Effect of Groundwater Depression Cone on the Hydrochemical Evolution Process in the People’s Victory Canal Irrigation Area, China." Processes 10, no. 12 (December 1, 2022): 2563. http://dx.doi.org/10.3390/pr10122563.

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The over−exploitation of shallow groundwater in the People’s Victory Canal irrigation area has led to the continuous decline in the groundwater level. The formation of a groundwater drawdown cone has changed the original runoff conditions and hydrochemical environment. Based on the groundwater data in the irrigated area from 1996 to 2022, multivariate statistical analysis, traditional hydrochemical methods, and inverse geochemical modeling were used to reveal the impact of the formation of the groundwater depression cone on hydrochemical evolution. The results show that the formation of the groundwater depression cone near the central area in 2003 changed the direction of the canal head flowing to the northwest area, making the groundwater flow from the canal head and the northwest area to the central area. The change in the hydrodynamic fields also caused the groundwater with high salinity in the northwest region to flow to the funnel area, and the ion concentration of groundwater along the pathway area to increase. The groundwater type in the runoff area changes, gradually evolving from Group 1 to Group 2 groundwater. Analysis of the hydrochemical characteristics of groundwater in the runoff area for many years shows that after the formation of the central funnel area in 2003, the groundwater with high ion in the northwest area flows to the funnel area, and the correlation between total dissolved solids and ions in the groundwater along the way is significantly enhanced. The inverse geochemical modeling shows that the main water–rock action along the runoff direction is the dissolution of halite and gypsum. In addition, the study area has a strong cation exchange reaction.

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Кузьмин, В. В., and К. А. Болдырев. "Hydrochemical modeling of migration of dissolved oil products in groundwater." Vodosnabzhenie i sanitarnaia tehnika, no. 11 (November 17, 2021): 43–51. http://dx.doi.org/10.35776/vst.2021.11.05.

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Изложена методика прогнозирования распространения нефтепродуктов группы BTEX (бензол, толуол, этилбензол, ксилолы) в подземных водах на основе гидрохимического моделирования с учетом изменения окислительно-восстановительных и кислотно-щелочных свойств раствора в процессе биодеградации нефтепродуктов. Представлена геохимическая модель биологического разложения нефтепродуктов комплекса BTEX на основе модифицированной кинетики Моно с учетом реакций между акцепторами, продуктами реакции биодеградации и неорганическими компонентами раствора. Приведены примеры геохимического моделирования, демонстрирующие важность учета процессов, связанных с изменением гидрогеохимической обстановки в подземных водах при разложении углеводородов. Разработанная модель может быть использована для выполнения геохимических прогнозов распространения легких нефтепродуктов в подземных водах, проведения работ в рамках оценки воздействия на природную среду, разработки систем инженерной защиты подземных вод от загрязнения нефтепродуктами. A method for predicting the spread of BTEX group oil products (benzene, toluene, ethylbenzene, xylenes) in groundwater based on hydrochemical modeling with account of changes in the redox, acidity or alkalinity of the solution during the biodegradation of oil products is stated. A geochemical model of the biological decomposition of oil products of BTEX group based on modified Mono kinetics with account of the reactions between acceptors, biodegradation products and inorganic components of the solution is presented. Examples of geochemical modeling are given that demonstrate the importance of taking into account the processes associated with the changes in the hydrogeochemical environment in groundwater during the decomposition of hydrocarbons. The developed model can be used to carry out geochemical predictions of the spread of light-end oil products in groundwater, to carry out works within the framework of estimating the environmental impact, and to develop systems for engineering protection of groundwater from oil pollution.

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Yu, Xiao, Yunhui Zhang, Pei Liu, Haoqing Huang, and Xun Huang. "Hydrochemical characteristics and D–O–Sr isotopes of groundwater and surface water in the northern Longzi county of southern Tibet (southwestern China)." Open Geosciences 14, no. 1 (January 1, 2022): 111–19. http://dx.doi.org/10.1515/geo-2020-0334.

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Abstract The protection of water resource has been the significant mission globally. Hydrochemical compositions and recharge source are the critical tools to analyze the water quality. In this study, 18 surface water and 5 groundwater samples were collected along the Xiongqu and Sequ rivers in the northern Longzi county of southern Tibet. The combination of factor analysis, correlation of major ions, geochemical modeling, and D–O–Sr isotopes were employed to clarify the hydrochemical compositions and recharge source. The concentration of major ions followed the abundance order of SO 4 2 − {\text{SO}}_{4}^{2-} > HCO 3 − {\text{HCO}}_{3}^{-} > Cl− for anions and Ca2+ > Mg2+ > Na+ > K+ for cations. Ca–HCO3 and Ca–SO4 types were identified for groundwater and surface water. Based on ratios of major ions and geochemical modeling, it is proposed that the dissolutions of gypsum, calcite, and dolomite controlled the hydrochemical compositions. D–O isotopes indicated a meteoric origin for surface water and groundwater, with the recharge elevation of 2,519–3,731 m. The 87Sr/86Sr ratios of groundwater and surface water were compatible with those of sulfate and carbonate minerals, revealing the main type of minerals interacting with water. The achievements of this study can provide a vital reference for groundwater utilization and protection in the Longzi county and adjacent areas in the Tibet.

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Novotni-Horčička, Nikolina, Tamara Marković, Igor Karlović, and Ivan Kovač. "Application of Hydrochemical Parameters as Tool for Sustainable Management of Water Supply Network." Sustainability 16, no. 21 (November 2, 2024): 9558. http://dx.doi.org/10.3390/su16219558.

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Effective management of Water Supply Systems (WSSs) is crucial for ensuring safe drinking water. The WSS of Varaždin County is a complex network involving three groundwater sources: Bartolovec and Vinokovščak wellfields (alluvial aquifers) and Bela karstic spring. To achieve a comprehensive characterization of WSSs, routine laboratory data was integrated with stable isotopes and geochemical modeling. Within this study, all measured parameters remain below the Maximum Contaminant Level (MCL), ensuring water safety for human consumption. The Piper diagram identified variations in water sources based on their chemical composition, providing a simplified overview of mixing patterns within WSSs. Among the modeling approaches, inverse modeling (IM) was found to be more reliable than forward modeling (FM) and mass balance modeling (MB). Despite the limited capacity of δ18O to provide accurate mixing results, it was revealed that the reservoir water was in equilibrium with the air (no evaporation effects), indicating well-sealed reservoirs. Mixing modeling showed that the western, southwestern, and northern parts of the WSS mixed all three sources, whereas the eastern and southeastern areas primarily relied on the deeper aquifer of the Bartolovec source, indicating potential vulnerability. Strict validation criteria ensured the reliability of results, demonstrating the effectiveness and applicability of geochemical modeling in water security management plans.

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Ma, Qingshan, Weiya Ge, and Fujin Tian. "Geochemical Characteristics and Controlling Factors of Chemical Composition of Groundwater in a Part of the Nanchang Section of Ganfu Plain." Sustainability 14, no. 13 (June 30, 2022): 7976. http://dx.doi.org/10.3390/su14137976.

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This work aims to investigate the hydrochemical characteristics and formation mechanisms of shallow groundwater in a part of the Nanchang section of Ganfu plain. The hydrochemical data from 90 groundwater samples were interpreted by the methods of mathematical statistics, Piper diagrams, Gibbs plots, ratio graphs of ions, and geochemical modeling. The results show that shallow groundwater is weakly acidic, the average concentration of cation in groundwater decrease in Ca2+ > Na+ > Mg2+ > K+, and the abundance is in the order HCO3− > NO3− > SO42− > Cl− for anions. The hydrochemical type of groundwater was dominated by HCO3-Na·Ca·Mg, HCO3·Cl-Na·Ca·Mg, and HCO3-Na·Ca. Moreover, the main controlling factor of groundwater hydrochemistry is water-rock interactions. Na+ and K+ mainly originate from the dissolution of halite. Ca2+ and Mg2+ are mainly controlled by carbonate dissolution, while the main anions come from the dissolution of evaporite and carbonate. The groundwater chemical evolution is affected by the dissolution and precipitation of the mineral phase and cation exchange.

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Olariu, Andra, and Marin Palcu. "The origin of ammonium in carbonated mineral waters and its underground transport to one production well in Middle Ciuc Depression from Eastern Carpathians." SIMI 2019, SIMI 2019 (September 20, 2019): 259–78. http://dx.doi.org/10.21698/simi.2019.fp34.

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In many cases in Romania, the mineral waters (in the Neogene Volcanic area of the Eastern Carpathians), especially the carbonate waters, have ammonium in concentration over 0.5 mg/l. The main issue regarding the presence of ammonium is identifying if the concentration is due to the anthropogenic pollution or it is of endogenic origin. The geological, hydrogeological and hydrochemical data analysis resulted in a conceptual model of the aquifer’s spatial position, groundwater movement and mineralization, and ammonium occurrence. The geological and tectonic aspects, aquifer’s recharging, groundwater flow direction, absence of surface pollution sources and correlation of hydrochemical data, all indicate the underground origin of ammonium. The aquifer is generated in pliocene - quaternary granular deposits. In the basement of these granular deposits, in the fracture areas, the groundwater is mixed with carbon dioxide and ammonium emissions, produced in the volcanic chambers. The surface data correlation and the hydrochemical data analysis resulted in the confirmation of the deep ammonium origin. After groundwater flow modeling and ammonium transport simulation, the ammonium plume size and preferential transport directions have been finally elucidated.

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IWATSUKI, Teruki, Takashi MIZUNO, Takanori KUNIMARU, Yuki AMANO, Tatsuji MATSUZAKI, and Takeshi SEMBA. "Expert system of hydrochemical modeling methods for geological disposal of HLW." Journal of Nuclear Fuel Cycle and Environment 19, no. 2 (2012): 51–64. http://dx.doi.org/10.3327/jnuce.19.51.

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El Alfy, Mohamed. "Hydrochemical Modeling and Assessment of Groundwater Contamination in Northwest Sinai, Egypt." Water Environment Research 85, no. 3 (March 1, 2013): 211–23. http://dx.doi.org/10.2175/106143012x13560205145055.

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Korshenko, A. N., A. R. Alyautdinov, and L. A. Ushakova. "MODELING AND ANALYSIS OF SPATIAL HYDROCHEMICAL STATE OF NEVA BAY WATERS." Proceedings of the International conference “InterCarto/InterGIS” 1, no. 22 (January 1, 2016): 120–27. http://dx.doi.org/10.24057/2414-9179-2016-1-22-120-127.

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Kazmierczak, J., S. Müller, B. Nilsson, D. Postma, J. Czekaj, E. Sebok, S. Jessen, et al. "Groundwater flow and heterogeneous discharge into a seepage lake: Combined use of physical methods and hydrochemical tracers." Water Resources Research 52, no. 11 (November 2016): 9109–30. http://dx.doi.org/10.1002/2016wr019326.

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AbstractGroundwater discharge into a seepage lake was investigated by combining flux measurements, hydrochemical tracers, geological information, and a telescopic modeling approach using first two‐dimensional (2‐D) regional then 2‐D local flow and flow path models. Discharge measurements and hydrochemical tracers supplement each other. Discharge measurements yield flux estimates but rarely provide information about the origin and flow path of the water. Hydrochemical tracers may reveal the origin and flow path of the water but rarely provide any information about the flux. While aquifer interacting with the lake remained under seemingly steady state conditions across seasons, a high spatial and temporal heterogeneity in the discharge to the lake was observed. The results showed that part of the groundwater flowing from the west passes beneath the lake and discharges at the eastern shore, where groundwater springs and high discharge zones (HDZs) are observed at the lake bottom and at seepage faces adjacent to the lake. In the 2‐D cross section, surface runoff from the seepage faces delivers 64% of the total groundwater inputs to the lake, and a 2 m wide offshore HDZ delivers 13%. Presence of HDZs may control nutrient fluxes to the lake.

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Пичугина, Анна Игоревна, and Дарья Дмитриевна Гончар. "MECHANISM OF HYDROCHEMICAL OXIDATION OF HEAZLEWOODITE IN NITRIC ACID." Вестник Тверского государственного университета. Серия: Химия, no. 4(42) (December 21, 2020): 83–89. http://dx.doi.org/10.26456/vtchem2020.4.9.

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В работе представлена математическая модель гидрохимического окисления хизлевудита в разбавленных растворах азотной кислоты. Дана физико-химическая интерпретация основных кинетических характеристик процесса растворения: константа скорости и эффективная энергия активации. Установлены режимы взаимодействия хизлевудита с азотной кислотой, выявлены вероятные лимитирующие стадии. По наблюдаемым кинетическим закономерностям при моделировании процесса, предложен механизм гидрохимического окисления хизлевудита. The paper presents a mathematical model of the hydrochemical oxidation of heazlewoodite in dilute solutions of nitric acid. A physicochemical interpretation of the main kinetic characteristics of the dissolution process is given: the rate constant and the effective activation energy. The modes of interaction of heazlewoodite with nitric acid have been established, and probable limiting stages have been identified. According to the observed kinetic regularities in modeling the process, a mechanism for the hydrochemical oxidation of heazlewoodite has been proposed.

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Titov, Konstantin V., Alexander Levitski, Pavel K. Konosavski, Andrey V. Tarasov, Yuri T. Ilyin, and Michel A. Buès. "Combined application of surface geoelectrical methods for groundwater flow modeling: A case history." GEOPHYSICS 70, no. 5 (September 2005): H21—H31. http://dx.doi.org/10.1190/1.2076747.

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Electrical methods [electrical profiling and sounding, induced polarization (IP), and self-potential (SP)], combined with geochemical and hydrochemical surveys, were applied to characterize shallow sediments at a site contaminated by oil-related brines. The site is located within the Romashkinskoye oil field (Tatarstan Republic, Russian Federation). Results of geochemical and hydrochemical surveys, as well as those of electrical profiling, revealed no individual haloes of contaminant in the soil and groundwater, which suggests that the entire site is contaminated. Vertical electrical IP soundings (VES-IP) allowed us to obtain the stratigraphic characteristics of the site and to distinguish a shallow aquifer among clayey aquitards. Interpretation of SP data on the basis of forward numerical modeling helped us to develop a groundwater-flow model of the site. To reduce ambiguities, we kept fixed the values of layer resistivity derived from the inverted VES-IP data. Boundary conditions on water head and water flow were based on drilling and sampling data. We varied only the values of hydraulic conductivity to fit the calculated SP values to the measured SP values. We found a strong misfit between the measured and calculated SP values for the one-aquifer model. By inferring a second, deeper-seated aquifer, we computed a two-aquifer model that produced a satisfactory SP fit.

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21

Beretta, Giovanni Pietro, Monica Avanzini, Tomaso Marangoni, Marino Burini, Giacomo Schirò, Jacopo Terrenghi, and Gaetano Vacca. "Groundwater modeling of the withdrawal sustainability of Cannara artesian aquifer (Umbria, Italy)." Acque Sotterranee - Italian Journal of Groundwater 7, no. 3 (September 25, 2018): 47–60. http://dx.doi.org/10.7343/as-2018-333.

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Abstract (sommario):

The Cannara aquifer (Umbria, Italy) has been known for more than a century, and is one of the main drinking water supplies in the Umbria Region. In the beginning it was used for irrigation purposes, since this area was mainly agricultural up to the 1960s. The groundwater—exploited by Umbra Acque S.p.A. (a Company supplying drinking water)—is 150 m under ground level and is contained in a porous confined aquifer, which originally had artesian characteristics. Exploitation of 200–300 l/s with nine wells caused a reduction of piezometric level, maintaining the confined aquifer conditions, except for a very short period during which the aquifer was depressurised by drought, and for increase of emergency withdrawals replacing other water supplies (from springs) for drinking purposes. The occasional presence of iron and ammonium ions confirms the confinement of the groundwater and their hydrochemical facies in a redox environment, while in nearby areas and shallow aquifers anthropogenic contaminants (nitrates and chlorinated solvents) are reported. For the protection of this aquifer of strategic interest (the most important well field in Umbria), all hydrological and hydrochemical data available have been reviewed, and the aquifer recharge studied. Sustainable rates of withdrawal, and groundwater protection areas have been identified using a numerical flow model. Further action for monitoring groundwater of both shallow and artesian aquifers, together with well-revamping, have been proposed.

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22

Siddique, Jamil, Jin Menggui, Munir H. Shah, Asfandyar Shahab, Faisal Rehman, and Umair Rasool. "Integrated Approach to Hydrogeochemical Appraisal and Quality Assessment of Groundwater from Sargodha District, Pakistan." Geofluids 2020 (December 29, 2020): 1–15. http://dx.doi.org/10.1155/2020/6621038.

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Abstract (sommario):

Hydrochemical characteristics and aquifer properties present a better understanding of the mitigation of groundwater pollution, which has become one of the leading environmental concerns and threats to the sustainable ecosystem. Seventy-seven groundwater samples were collected from Sargodha District (Pakistan) and characterized for their physical and chemical properties. The analytical data were processed for the evaluation of the processes that control the groundwater chemistry using various drinking and agricultural indices with statistical and hydrochemical modeling. The predominant hydrochemical type was found to be Ca-HCO3 type, followed by Na-HCO3 and Mg-Ca-Cl types. The present study showed that the main factors controlling the groundwater chemistry were the prevalent rock dominance alongside the weathering of silicates, solubilization of carbonates, and cation exchange processes. Entropy water quality index (EWQI) revealed that 6.51% represented “poor water,” while 7.79% were considered “extremely poor” for drinking purposes. However, USSL classification, Wilcox diagram, and other agricultural indices (RCS, SAR, %Na, MH, PI, and PS) showed that the majority of the samples were classified as suitable for irrigation purpose. However, 16% of the samples for %Na and 24% of the samples for MH were not suitable for agricultural purposes. Overall, the groundwater quality was affected by the anthropogenic stress in the study area.

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23

Wang, Rui, Xiaohan Li, Fenggang Dai, Zhichao Cai, Wenbo He, Lulu Song, and Zhoupan Jiang. "Hydrochemical Response of Karst Groundwater to Rapid Urbanization in Xingtai, North China." Water 15, no. 12 (June 20, 2023): 2304. http://dx.doi.org/10.3390/w15122304.

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Abstract (sommario):

Karst groundwater is the main water source for domestic, industrial, and agricultural needs in Xingtai City, North China. The objective of this study was to comprehensively access changes in the hydrochemical characteristics and evolution of karst groundwater in response to rapid urbanization. Water samples from the late 2010s and the 1970s were compared utilizing statistical analysis, hydrochemical diagrams, and inverse simulation technology. The total dissolved solids (TDS), total hardness (TH), NO3−, and Fe contents were significantly higher in the more recently obtained karst groundwater samples. Further, the dominance of HCO3-Ca-type water decreased, with new types emerging, relative to 1970s karst groundwater. Abnormal TDS, TH, SO42−, NO3−, and Cl− concentrations can be attributed to sewage discharge and fertilizer. Two groundwater discharge areas around the center of Xingtai City and Yangfan Town in the south of the study area were the most significantly affected by human activities. However, inverse modeling indicated that the dissolution of gypsum and halite, as well as cation-exchange processes, occurred in the groundwater paths during both periods. Recent increases in ion concentrations of karst groundwater in the study area have caused carbonate minerals to dissolve, resulting in a further increase of ion concentrations. The hydrochemical response and evolution of karst groundwater requires further study.

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24

Raffensperger, J. P., and G. Garven. "The formation of unconformity-type uranium ore deposits; 2, Coupled hydrochemical modeling." American Journal of Science 295, no. 6 (June 1, 1995): 639–96. http://dx.doi.org/10.2475/ajs.295.6.639.

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25

Wang, Ziqi, Ting Lu, Shengnan Li, Kexin Zhou, Yidong Gu, Bihui Wang, and Yudong Lu. "Hydrochemical Characteristics and Evolution Laws of Groundwater in Huangshui River Basin, Qinghai." Water 17, no. 9 (April 30, 2025): 1349. https://doi.org/10.3390/w17091349.

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Abstract (sommario):

Groundwater plays a leading role in ecological environment protection in semi-arid regions. The Huangshui River Basin is located in the Tibetan Plateau and Loess Plateau transition zone of semi-arid areas. Its ecological environment is relatively fragile, and there is an urgent need for systematic study of the basin to develop a groundwater environment and realize the rational and efficient development of water resources. In this study, methodologically, we combined the following: 1. Field sampling (271 groundwater samples across the basin’s hydrogeological units); 2. Comprehensive laboratory analysis of major ions and physicochemical parameters; 3. Multivariate statistical analysis (Pearson correlation, descriptive statistics); 4. Geospatial techniques (ArcGIS kriging interpolation); 5. Hydrochemical modeling (Piper diagrams, Gibbs plots, PHREEQC simulations). Key findings reveal the following: 1. Groundwater is generally weakly alkaline (pH 6.94–8.91) with TDS ranging 155–10,387 mg/L; 2. Clear spatial trends: TDS and major ions (Na+, Ca2+, Mg2+, Cl−, SO42−) increase along flow paths; 3. Water types evolve from Ca-HCO3-dominant (upper reaches) to complex Ca-SO4/Ca-Cl mixtures (lower reaches); 4. Water–rock interactions dominate hydrochemical evolution, with secondary cation exchange effects; 5. PHREEQC modeling identifies dominant carbonate dissolution (mean SIcalcite = −0.32) with localized evaporite influences (SIgypsum up to 0.12). By combining theoretical calculations and experimental results, this study reveals distinct hydrochemical patterns and evolution mechanisms. The groundwater transitions from Ca-HCO3-type in upstream areas to complex Ca-SO4/Cl mixtures downstream, driven primarily by dissolution of gypsum and carbonate minerals. Total dissolved solids increase dramatically along flow paths (155–10,387 mg/L), with Na+ and SO42− showing the strongest correlation to mineralization (r > 0.9). Cation exchange processes and anthropogenic inputs further modify water chemistry in midstream regions. These findings establish a baseline for sustainable groundwater management in this ecologically vulnerable basin.

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26

Mohebbi Tafreshi, Ghazaleh, and Amin Mohebbi Tafreshi. "Statistical approaches and hydrochemical modeling of groundwater in the Golpayegan Plain aquifer, Iran." Modeling Earth Systems and Environment 6, no. 4 (June 6, 2020): 2391–404. http://dx.doi.org/10.1007/s40808-020-00822-w.

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27

Wästeby, Niklas, Alasdair Skelton, Elin Tollefsen, Margareta Andrén, Gabrielle Stockmann, Lillemor Claesson Liljedahl, Erik Sturkell, and Magnus Mörth. "Hydrochemical monitoring, petrological observation, and geochemical modeling of fault healing after an earthquake." Journal of Geophysical Research: Solid Earth 119, no. 7 (July 2014): 5727–40. http://dx.doi.org/10.1002/2013jb010715.

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28

Sha, Jian, Xue Li, and Jingjing Yang. "Estimation of Watershed Hydrochemical Responses to Future Climate Changes Based on CMIP6 Scenarios in the Tianhe River (China)." Sustainability 13, no. 18 (September 9, 2021): 10102. http://dx.doi.org/10.3390/su131810102.

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Abstract (sommario):

The impacts of future climate changes on watershed hydrochemical processes were assessed based on the newest Shared Socioeconomic Pathways (SSP) scenarios in Coupled Model Intercomparison Project Phase 6 (CMIP6) in the Tianhe River in the middle area of China. The monthly spatial downscaled outputs of General Circulation Models (GCMs) were used, and a new Python procedure was developed to batch pick up site-scale climate change information. A combined modeling approach was proposed to estimate the responses of the streamflow and Total Dissolved Nitrogen (TDN) fluxes to four climate change scenarios during four future periods. The Long Ashton Research Station Weather Generator (LARS-WG) was used to generate synthetic daily weather series, which were further used in the Regional Nutrient Management (ReNuMa) model for scenario analyses of watershed hydrochemical process responses. The results showed that there would be 2–3% decreases in annual streamflow by the end of this century for most scenarios except SSP 1-26. More streamflow is expected in the summer months, responding to most climate change scenarios. The annual TDN fluxes would continue to increase in the future under the uncontrolled climate scenarios, with more non-point source contributions during the high-flow periods in the summer. The intensities of the TDN flux increasing under the emission-controlled climate scenarios would be relatively moderate, with a turning point around the 2070s, indicating that positive climate policies could be effective for mitigating the impacts of future climate changes on watershed hydrochemical processes.

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29

Dar’ya Ivanovna, PETROVA. "Technogenic transformation of the underground hydrosphere of Kazan. Lower Kazanian aquifer complex." NEWS of the Ural State Mining University, no. 2 (June 15, 2021): 114–22. http://dx.doi.org/10.21440/2307-2091-2021-2-114-122.

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Abstract (sommario):

Relevance. By the beginning of the XXI century, the growth of cities, population concentration and the revival of industrial production led to an intense technogenic pressure on the underground hydrosphere. In ecological and hydrogeological studies, it becomes necessary to conduct monitoring observations of groundwater based on GIS technologies. Purpose of the work: study of the hydrogeochemical characteristics of underground waters of the aquiferous lower Kazanian carbonate-terrigenous complex to provide Kazan with high-quality drinking water from protected underground sources. Research methodology. Hydrochemical data from geological reports and archival materials for the period from 1960 years to 2019 years were used. Methods of mathematical statistics (basic, cluster and factor analyzes) made it possible to differentiate into natural and man-made components. Geographic information modeling using the “ArcGisMap” package showed the spatial variability of the main components in the waters of the Neogene complex at the turn of the 20th and 21st centuries. Conclusion. The hydrochemical parameters of the aquiferous lower Kazanian complex are assessed as favorable, since practically all the main components do not exceed the MPC values for drinking water.

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30

Sasamoto, Hiroshi, Mikazu Yui, and Randolph C. Arthur. "Hydrochemical characteristics and groundwater evolution modeling in sedimentary rocks of the Tono mine, Japan." Physics and Chemistry of the Earth, Parts A/B/C 29, no. 1 (January 2004): 43–54. http://dx.doi.org/10.1016/j.pce.2003.11.003.

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31

Chen, Kouping, and Jiu Jimmy Jiao. "Modeling freshening time and hydrochemical evolution of groundwater in coastal aquifers of Shenzhen, China." Environmental Earth Sciences 71, no. 5 (November 27, 2013): 2409–18. http://dx.doi.org/10.1007/s12665-013-2641-3.

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32

Bulavina, Aleksandra. "Modeling of water pollution in the basins of Arctic rivers." E3S Web of Conferences 390 (2023): 04009. http://dx.doi.org/10.1051/e3sconf/202339004009.

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Abstract (sommario):

The goal hereof is mainly to model water pollution in the Arctic rivers on the basis of known natural and anthropogenic data on the drainage basins. The quality of water in rivers depends on the amount of pollutants entering the drainage basin and on the latter’s ability to convert such substances. This paper investigates merging these two components into a single integral model by finding a balanced system of inputs. After reviewing the literature and theorizing on the concept, the model was tested on the river systems of the European part of the Russian Arctic. The experiments proved the integral river pollution model to be objective. The resulting integral indices show the extent of anthropogenic impacts on river waters. The use of integral indices in conjunction with hydrochemical ones gives insight into how far anthropogenic sources of chemicals affect the composition of river waters.

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33

Glok Galli, M., D. E. Martínez, and E. E. Kruse. "The carbon budget of a large catchment in the Argentine Pampa plain through hydrochemical modeling." Science of The Total Environment 493 (September 2014): 649–55. http://dx.doi.org/10.1016/j.scitotenv.2014.06.032.

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34

Olofinlade, W. S., S. O. Daramola, and O. F. Olabode. "Hydrochemical and statistical modeling of groundwater quality in two constrasting geological terrains of southwestern Nigeria." Modeling Earth Systems and Environment 4, no. 4 (June 15, 2018): 1405–21. http://dx.doi.org/10.1007/s40808-018-0486-1.

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35

Varotsos, Costas A., Vladimir F. Krapivin, Ferdenant A. Mkrtchyan, and Yong Xue. "Optical Spectral Tools for Diagnosing Water Media Quality: A Case Study on the Angara/Yenisey River System in the Siberian Region." Land 10, no. 4 (March 27, 2021): 342. http://dx.doi.org/10.3390/land10040342.

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Abstract (sommario):

This paper presents the results of spectral optical measurements of hydrochemical characteristics in the Angara/Yenisei river system (AYRS) extending from Lake Baikal to the estuary of the Yenisei River. For the first time, such large-scale observations were made as part of a joint American-Russian expedition in July and August of 1995, when concentrations of radionuclides, heavy metals, and oil hydrocarbons were assessed. The results of this study were obtained as part of the Russian hydrochemical expedition in July and August, 2019. For in situ measurements and sampling at 14 sampling sites, three optical spectral instruments and appropriate software were used, including big data processing algorithms and an AYRS simulation model. The results show that the water quality in AYRS has improved slightly due to the reasonably reduced anthropogenic industrial impact. Chemical concentrations in water have been found to vary along the Angara River depending on the location of the dams. The results of in situ measurements and modeling evaluations are given. To overcome the uncertainties in the data caused by the large monitoring area, it is recommended to use the combined AYRS simulation model and the universal 8-channel spectrophotometer installed on a fixed platform for continuous monitoring.

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36

El Chaal, Rachid, Khalid Hamdane, and Moulay Othman Aboutafail. "Application of Multidimensional Statistical Methods to the Hydrochemical Study with R Software." Mathematical Modelling of Engineering Problems 9, no. 6 (December 31, 2022): 1669–78. http://dx.doi.org/10.18280/mmep.090628.

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Abstract (sommario):

Conducting extensive, time-consuming analysis campaigns is a typical technique to better understand and manage surface water quality. These usually generate a substantial amount of data that is challenging to comprehend. Principal component analysis may be advantageous for such a project (PCA). From the perspective of such an application, eight physico-chemical parameters are important: Sodium (Na+), Bicarbonate (HCO3-), Magnesium (Mg2+), Total Alkalinity (as CaCO3), Chlorides (Cl-), Potassium (K+), Calcium (Ca2+), Sulfates (SO42-), coming from the analysis of 100 water samples collected between February 2014 and December 2015 on 25 stations distributed on Inaouen catchment areas, were analyzed. The principal component analysis applied to the data showed that the variables could be grouped into two principal components. The interpretation of the results using these tools allowed us to understand that the parameters responsible for water quality are related to component Dim1 (HCO3-, CaCO3, K+, Cl-, Na+ and SO42-) and component Dim2 to the processes associated to (Ca2+ and Mg2+) for the physicochemical parameters, the Dim1 factorial design accounts for 67.80% of the variance; it is expressed towards its positive pole by HCO3-, CaCO3, K+, Cl-, Na+ and SO42-, which present good correlations between them. However, the Dim2 factorial plane represents only 17.60%, defined by the Ca2+ and Mg2+ ions towards its positive pole. The Dim1XDim2 plane's typological structure reveals the individualization of three different groupings based on their hydrochemical quality. A feasible reduction in the number of dimensions without a major loss of information was discovered by the PCA. This tool is a good choice from the standpoint of developing management tools.

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37

Moran-Ramirez, Janete, and Jose Alfredo Ramos-Leal. "The VISHMOD Methodology with Hydrochemical Modeling in Intermountain (Karstic) Aquifers: Case of the Sierra Madre Oriental, Mexico." Journal of Geography and Geology 6, no. 2 (May 7, 2014): 132. http://dx.doi.org/10.5539/jgg.v6n2p132.

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Abstract (sommario):

Hydrogeochemistry can be studied qualitatively using graphics such as scatter plots and Piper, Durov, and Schoeller diagrams, among others, and quantitatively by applying mass balance mixing models. The VISHMOD methodology (Virtual Samples in Hydrochemical Modeling) combines these two forms of hydrogeochemical characterizations. It is performed by applying hydrogeochemical modeling to virtual samples. This method makes standardization and control possible in order to demonstrate the extent to which a model is able to reproduce field measurements. Therefore, hydrogeochemical models of hydrogeological systems must be calibrated. This methodology was applied to carbonate and homogeneous media in the Sierra Madre Oriental in Mexico. Using the VISHMOD methodology in this region resulted in the classification of the water type as calcium bicarbonate (Ca-HCO3), representing a ternary mixture in which 45.5% was associated with local flow, 38.5% to intermediate flow and 16.5% to water-rock interaction. The main mineral phases were saturated calcite and sub-saturated dolomite, both from limestone contained in the Tamaulipas Formation.

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38

Peiyue, Li, Qian Hui, and Wu Jianhua. "Hydrochemical Formation Mechanisms and Quality Assessment of Groundwater with Improved TOPSIS Method in Pengyang County Northwest China." E-Journal of Chemistry 8, no. 3 (2011): 1164–73. http://dx.doi.org/10.1155/2011/251918.

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Abstract (sommario):

Inverse geochemical modeling was used in this paper to quantitatively study the formation mechanisms of groundwater in Pengyang County, China. An improved TOPSIS method based on entropy weight was used to perform groundwater quality assessment in this area. The assessment results show that the groundwater in the study area is fit for human consumption and the high concentrations of some elements can be attributed to the strong water-rock interactions. The inverse geochemical modeling reveals that the dominant reactions in different parts of the study area are different. In the south part of the study area, the precipitation of sodium montmorillonite, calcite and the dissolution of gypsum, fluorite, halite, albite and dolomite as well as CO2dissolution and cation exchange are the major water-rock interactions, while in the north part, the leading reactions are the precipitation of gypsum, dolomite, sodium montmorillonite, fluorite, the dissolution of calcite and albite and the CO2emission and cation exchange are also important. All these reactions are influenced by the initial aquatic environment and hydrodynamic conditions of the flow path.

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39

Bergström, S., B. Carlsson, G. Sandberg, and L. Maxe. "Integrated Modelling of Runoff, Alkalinity, and pH on a Daily Basis." Hydrology Research 16, no. 2 (April 1, 1985): 89–104. http://dx.doi.org/10.2166/nh.1985.0008.

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Abstract (sommario):

Based on the experience from runoff and groundwater recharge simulation a model system has been developed for terrestrial, hydrochemical, and hydrological simulations. The system emphasizes the role of temporary or long term storage in the aquifers of a basin and, separately, accounts for each rainfall or snowmelt event from its entrance into the ground until mixing in the river system. The model is primarily intended for simulation of natural short term variations in alkalinity and pH in running waters. The hydrochemical processes are modelled in a semi-empirical way without assumption of complete hydrochemichal mass-balance. In the paper a brief hydrochemical background is given, and a model with two alternative hydrochemical sub-structures is described. Examples of daily simulations of runoff alkalinity and pH from three different basins are given.

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40

Pinault, J. L., V. Plagnes, L. Aquilina, and M. Bakalowicz. "Inverse modeling of the hydrological and the hydrochemical behavior of hydrosystems: Characterization of Karst System Functioning." Water Resources Research 37, no. 8 (August 2001): 2191–204. http://dx.doi.org/10.1029/2001wr900018.

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41

Duan, Rui, Liang Chang, Xiaofan Gu, Xiaodeng Li, Xiangzhi You, Qunhui Zhang, and Qian Wang. "The Hydrogeochemical Processes of Groundwater in the Bieletan Area, the Western Potash Production Region in China." Water 16, no. 13 (June 27, 2024): 1833. http://dx.doi.org/10.3390/w16131833.

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Abstract (sommario):

The hydrogeochemical research of groundwater in the Bieletan area, China’s largest potash producing zone, used a variety of methods, including multivariate analysis, saturation index, and hydrogeochemical modeling. Water samples were collected and analyzed for physicochemical parameters, along with soluble ions from soil cores. The results showed that total dissolved solids (TDS) of groundwater exceeded 300 g/L, with the main hydrochemical characteristics being Cl-Mg type and Cl-Na type. Groundwater is recharged by lake water and canal water, with evaporation being the main factor affecting water chemistry. Hydrogeochemical modeling analyzed the processes occurring from these two different recharge sources: mineral precipitation mainly occurred with lake water recharge, while mineral dissolution mainly occurred with canal water recharge. Regarding potash dissolution, canal water and lake water recharge resulted in 8.860 mmol/L of polyhalite dissolution and 0.278 mmol/L of carnallite dissolution, respectively. This study highlights the complex hydrogeochemical processes controlling groundwater in the potash-rich Bieletan area, providing insights for water resource management and potash mining.

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42

Kayukova, E. P., and E. A. Filimonova. "Quality of fresh groundwater of the Crimean Mountains (the Bodrak River Basin)." Moscow University Bulletin. Series 4. Geology, no. 1 (December 15, 2022): 79–88. http://dx.doi.org/10.33623/0579-9406-2022-1-79-88.

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Abstract (sommario):

The quality of fresh groundwater in the foothills of the Crimea, including that used for the water supply of the Crimean base of St. Petersburg State University and the Crimean educational and scientific center of Lomonosov Moscow State University, is considered. The results of longterm monitoring of the chemical composition of fresh water used for drinking purposes are presented and priority pollutants are identified. Hydrochemical modeling was carried out to calculate transport forms of chemical elements and subsequent assessment of their toxicity. The study area is located in the area of active water exchange, so in the groundwater most of the chemical elements are contained in concentrations below the level of biologically significant.

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43

Delsman, J. R., K. R. M. Hu-a-ng, P. C. Vos, P. G. B. de Louw, G. H. P. Oude Essink, P. J. Stuyfzand, and M. F. P. Bierkens. "Paleo-modeling of coastal saltwater intrusion during the Holocene: an application to the Netherlands." Hydrology and Earth System Sciences 18, no. 10 (October 2, 2014): 3891–905. http://dx.doi.org/10.5194/hess-18-3891-2014.

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Abstract (sommario):

Abstract. Coastal groundwater reserves often reflect a complex evolution of marine transgressions and regressions, and are only rarely in equilibrium with current boundary conditions. Understanding and managing the present-day distribution and future development of these reserves and their hydrochemical characteristics therefore requires insight into their complex evolution history. In this paper, we construct a paleo-hydrogeological model, together with groundwater age and origin calculations, to simulate, study and evaluate the evolution of groundwater salinity in the coastal area of the Netherlands throughout the last 8.5 kyr of the Holocene. While intended as a conceptual tool, confidence in our model results is warranted by a good correspondence with a hydrochemical characterization of groundwater origin. Throughout the modeled period, coastal groundwater distribution never reached equilibrium with contemporaneous boundary conditions. This result highlights the importance of historically changing boundary conditions in shaping the present-day distribution of groundwater and its chemical composition. As such, it acts as a warning against the common use of a steady-state situation given present-day boundary conditions to initialize groundwater transport modeling in complex coastal aquifers or, more general, against explaining existing groundwater composition patterns from the currently existing flow situation. The importance of historical boundary conditions not only holds true for the effects of the large-scale marine transgression around 5 kyr BC that thoroughly reworked groundwater composition, but also for the more local effects of a temporary gaining river system still recognizable today. Model results further attest to the impact of groundwater density differences on coastal groundwater flow on millennial timescales and highlight their importance in shaping today's groundwater salinity distribution. We found free convection to drive large-scale fingered infiltration of seawater to depths of 200 m within decades after a marine transgression, displacing the originally present groundwater upwards. Subsequent infiltration of fresh meteoric water was, in contrast, hampered by the existing density gradient. We observed discontinuous aquitards to exert a significant control on infiltration patterns and the resulting evolution of groundwater salinity. Finally, adding to a long-term scientific debate on the origins of groundwater salinity in Dutch coastal aquifers, our modeling results suggest a more significant role of pre-Holocene groundwater in the present-day groundwater salinity distribution in the Netherlands than previously recognized. Though conceptual, comprehensively modeling the Holocene evolution of groundwater salinity, age and origin offered a unique view on the complex processes shaping groundwater in coastal aquifers over millennial timescales.

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44

Kirvel, Ivan, Vitalii Martyniuk, Ivan Kovalchuk, Ion Andronache, Vasyl Korbutiak, and Ivan Zubkovych. "A Cartographic Landscape Analysis of the Geo-Ecological Condition of the Natural Reserve Object—Lake Doshne (Volyn Polissya, Ukraine)." Limnological Review 24, no. 3 (September 18, 2024): 385–405. http://dx.doi.org/10.3390/limnolrev24030023.

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Abstract (sommario):

The cartographic landscape analysis of Lake Doshne employs geographic landscape methods, GIS cartographic modeling, and geo-ecological analysis. This study includes hydrochemical analysis of the lake’s water mass, focusing on saline blocks, tropho-saprobiological indicators, and specific toxic action indicators. Three geological sections of anthropogenic and pre-Quaternary complexes, along with a geological–lithological transverse profile of the lake basin, were developed. Additionally, a geographical landscape model of the lake’s natural aquatic complex was presented, distinguishing littoral–sublittoral and profundal aquatic sub-tracts and five types of aquafacies with landscape metric assessments. This approach enables a comprehensive analysis and the creation of cartographic models that can serve as a basis for lake cadastre and optimization of the ecological and landscape conditions in local territories.

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45

Zhuo, Linyang, Xun Zhou, Changpei Zou, Yanqiu Wu, Guangbin Tao, Ruirui Cheng, Yixuan Wang, and Jingru Ma. "Hydrochemical Characteristics and Association of Hot Springs on Small-Scale Faults in Southern Yunnan–Tibet Geothermal Zone." Water 17, no. 10 (May 14, 2025): 1481. https://doi.org/10.3390/w17101481.

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Abstract (sommario):

Hydrogeochemical characteristics and temperature variations in fault-controlled, deep-circulation thermal springs elucidate water–rock interaction dynamics and hydrothermal circulation depths, providing critical insights into fault permeability and stress accumulation. To investigate the coexistence of high-temperature and medium-low-temperature thermal springs on small-scale faults and their distinct circulation mechanisms, hydrochemical and isotopic analyses were conducted on 13 water samples (9 proximal on the Xiangbaihe Fault) in western Yunnan. The hot springs along the Xiangbaihe Fault are predominantly classified as the Na-HCO3 type, derived from carbonate and aluminosilicate hydrolysis. δ2H and δ18O confirmed a meteoric origin, with recharge elevations spanning 2465–3286 m (Gaoligong Mountain). Inverse hydrochemical modeling demonstrated progressive mineral transfer and water–rock interactions along the fault’s east–west axis. Conservative elements (Cl, Li) suggested a shared geothermal fluid source or reservoir affiliation. BLZ reservoir temperatures (194–221 °C) were classified as a high-temperature system, whereas others (58–150 °C) represented medium-low-temperature systems. Although each thermal spring represents a distinct geothermal system, reservoir interconnectivity is inferred. Notably, despite uniform lithology, variations in spring temperature and elemental composition are attributed to a subsurface magma chamber beneath BLZ, heterogeneous fault geometries, differential reservoir temperatures, and variable cold-water mixing ratios. This study establishes a framework for understanding groundwater circulation in small-scale fault-associated geothermal systems, with implications for tectonic activity monitoring and geothermal resource assessment.

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46

Pinault, J. L., H. Pauwels, and C. Cann. "Inverse modeling of the hydrological and the hydrochemical behavior of hydrosystems: Application to nitrate transport and denitrification." Water Resources Research 37, no. 8 (August 2001): 2179–90. http://dx.doi.org/10.1029/2001wr900017.

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Fashchevskaya, T. B., Yu G. Motovilov , and K. V. Kortunova. "Modeling the Genetic Components of the Water and Chemical Runoff of Heavy Metals in the Basin of the Nizhnekamskoe Reservoir." Водные ресурсы 50, no. 4 (July 1, 2023): 492–508. http://dx.doi.org/10.31857/s0321059623040077.

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Abstract (sommario):

A semi-distributed physical-mathematical model ECOMAG-HM is used to simulate the genetic structure of water and chemical runoff of copper, zinc, and manganese in a large river basin of the Nizhnekamsk Reservoir. The model was tested against long-term data of hydrological and hydrochemical monitoring of water bodies. The contributions of the surface, soil, and subsoil components of the water and chemical runoff of metals are estimated for different segments of river network. It was found that, in the major portion of the catchment, river pollution by metals is mostly due to their diffuse washout from the soil layer. The effect of the genetic structure of water and chemical runoff on the year-to-year and seasonal variations of metal concentrations in the river network is demonstrated.

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Gkiougkis, Ioannis, Christos Pouliaris, Fotios-Konstantinos Pliakas, Ioannis Diamantis, and Andreas Kallioras. "Conceptual and Mathematical Modeling of a Coastal Aquifer in Eastern Delta of R. Nestos (N. Greece)." Hydrology 8, no. 1 (January 29, 2021): 23. http://dx.doi.org/10.3390/hydrology8010023.

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In this paper, the development of the conceptual and groundwater flow model for the coastal aquifer system of the alluvial plain of River Nestos (N. Greece), that suffers from seawater intrusion due to over-pumping for irrigation, is analyzed. The study area is a typical semi-arid hydrogeologic environment, composed of a multi-layer granular aquifers that covers the eastern coastal delta system of R. Nestos. This study demonstrates the results of a series of field measurements (such as geophysical surveys, hydrochemical and isotopical measurements, hydro-meteorological data, land use, irrigation schemes) that were conducted during the period 2009 to 2014. The synthesis of the above resulted in the development of the conceptual model for this aquifer system, that formed the basis for the application of the mathematical model for simulating groundwater flow. The mathematical modeling was achieved using the finite difference method after the application of the USGS code MODFLOW-2005.

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Мкртчян, Ф. А., В. Ю. Солдатов та М. А. Мкртчян. "О МЕТОДАХ РЕШЕНИЯ ОБРАТНЫХ ЗАДАЧ В СПЕКТРОФОТОМЕТРИИ И СПЕКТРОЭЛЛИПСОМЕТРИИ". Проблемы окружающей среды и природных ресурсов, № 3 (1 березня 2024): 159–74. https://doi.org/10.36535/0235-5019-2024-03-4.

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Изложены результаты исследований по оценке возможностей применения сенсоров оптического и микроволнового диапазонов для диагностики состояния гидрофизических и гидрохимических систем различного пространственного масштаба. Разработан макет информационно-моделирующей системы для гидрохимических исследований (ИМСГИ), включающей сенсоры оптического и микроволнового диапазонов и обладающей функциями диагностики и адаптивной идентификации жидкостей. Система основана на формировании базы спектральных эталонов жидких растворов, получаемых с помощью многоканального спектрофотометра или спектроэллипсометра, и используемых для адаптивного распознавания спектральных образов. Процесс обучения и последующее распознавание реализуются в соответствии с определенным набором методик, алгоритмов и процедур сбора, анализа, сортировки и обработки данных измерений. Совокупность всех этих средств составляет структуру информационномоделирующей системы, ориентированной на оперативную диагностику состояния водных объектов в условиях многоканальных потоков информации от датчиков контактного и дистанционного действия и с применением высокоэффективных информационных технологий для решения задач классификации и идентификации водных объектов. Results of the investigations are stated in connection with the assessment of capabilities to use the sensors of optical and microwave ranges for the diagnostics of hydrophysical and hydrochemical systems having various spatial scales. Structure of information-modeling system for hydrochemical investigations (IMSHI) is synthesized. IMSHI consists the sensors of optical and microwave ranges and it realizes functions for the diagnostics and adaptive identification of the liquids. The system is based on the base formation of spectral standards for the liquid solutions delivered by means of multi-channel spectrophotometer or spectroellipsometer and used for adaptive recognition of spectral images. Education process and following recognition are realized in accordance with the certain series of the methods, algorithms and procedures for accumulation, analysis, sorting and observation data processing. Assembly of all tools forms the information-modeling system oriented on the operative diagnostics of the state of the water objects when multi-channel information is delivered by the on-site and remote sensors and high-performance information technologies are used for the solution of the tasks related to the classification and identification of the water objects.

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Ahmed, Nurudeen Onomhoale, Mohammed Bashir Suleiman, Finjite Dorathy Olali, Mojisola Mary Ogunkoya, Fayose Olalekan Oluwatobi, and Deborah Ifesinachi Elom Nwuzor. "Ionic Geospatialization and Hydrochemical Characterization of Water Resources around Selected Petroleum Producing Areas in South-Southern Nigeria." Journal of Applied Geospatial Information 8, no. 1 (June 11, 2024): 19–40. http://dx.doi.org/10.30871/jagi.v8i1.7406.

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Water resources play a crucial role in sustaining life and various socio-economic activities, especially in regions like South-Southern Nigeria, where petroleum production activities are prevalent. This study focuses on understanding the hydrochemical characteristics and geospatial distribution of major ions in water around selected petroleum-producing areas, notably within the Obigbo Local Government Area (L.G.A) of Rivers State. A total of 41 water samples, comprising 34 rain and 7 surface waters, were collected, and analyzed employing hydrochemical modeling techniques, including the Piper Trilinear plot, Durov, and Schoeller diagram, to characterize the ionic composition of surface water and rainwater. The analysis revealed a relatively uniform pattern of major ions, including Ca, Mg, Na, K, HCO3, Cl, SO4, and NO3, across the study area, with higher concentrations observed along the river channel, in the Northern regions. Rainwater samples exhibited lower concentrations, with discernible variations, especially in areas adjacent to petroleum activities. The dominance of Ca + Mg as cations and Cl as anions was consistent in both river water and rainwater samples. Durov diagram depicted a simple dissolution or mixing line in river water, while rainwater samples exhibited a notable presence of calcium and sulphate. The Schoeller diagram indicated a calcium chloride water type, with rainwater showing heightened calcium and sulphate concentrations. Geospatial analysis highlighted consistent ion concentration levels throughout the study area, suggesting environmental stability. Despite concerns about increased sulfate near petroleum facilities, all measured ion concentrations in both river and rainwater samples adhered to WHO standards, indicating satisfactory water quality.

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