scholarly journals Confronting vicinity of the surface water and sea shore in a shallow glaciogenic aquifer in southern Finland

2014 ◽  
Vol 11 (7) ◽  
pp. 8651-8695
Author(s):  
S. Luoma ◽  
J. Okkonen ◽  
K. Korkka-Niemi ◽  
N. Hendriksson ◽  
B. Backman

Abstract. The chemical characterization of groundwater in shallow, unconfined, low-lying coastal aquifer in Santala, southern Finland was identified by utilising the integrations of multivariate statistical approaches; principal component analysis (PCA) and hierarchical cluster analysis (HCA), with the stable isotope δ2H and δ18O, hydrogeochemistry and field monitoring data. HCA classified groundwater samples into 6 distinct groups that reveal the factors controlling temporal and spatial variations of groundwater geochemistry such as geology, anthropogenic sources from human activities, climate and surface water. High temporal variation of groundwater chemistry corresponds directly to precipitation. With increase in precipitation, KMnO4 consumption, EC, alkalinity and Ca concentrations also increase in most wells, while Fe, Al, Mn and SO4 are occasionally increased during spring after the snowmelt in specific geologic condition. The continued increase of NO3 and metals concentrations in groundwater indicates the potential contamination risk to aquifer. Stable isotopes of δ18O and δ2H indicate groundwater recharges directly from the meteoric water with insignificant contribution from lake water, and no seawater intrusion into the aquifer. Groundwater geochemistry suggests local seawater intrusion being temporary able to take place in the sulphate reduction zone along the fresh and seawater mixed zone in the low-lying coastal area but contribution of seawater was very low. The influence of lake water can be observed from the increases of KMnO4 consumption in wells nearby the lake.

2015 ◽  
Vol 19 (3) ◽  
pp. 1353-1370 ◽  
Author(s):  
S. Luoma ◽  
J. Okkonen ◽  
K. Korkka-Niemi ◽  
N. Hendriksson ◽  
B. Backman

Abstract. The groundwater in a shallow, unconfined, low-lying coastal aquifer in Santala, southern Finland, was chemically characterised by integrating multivariate statistical approaches, principal component analysis (PCA) and hierarchical cluster analysis (HCA), based on the stable isotopes δ2H and δ18O, hydrogeochemistry and field monitoring data. PCA and HCA yielded similar results and classified groundwater samples into six distinct groups that revealed the factors controlling temporal and spatial variations in the groundwater geochemistry, such as the geology, anthropogenic sources from human activities, climate and surface water. High temporal variation in groundwater chemistry directly corresponded to precipitation. With an increase in precipitation, KMnO4 consumption, EC, alkalinity and Ca concentrations also increased in most wells, while Fe, Al, Mn and SO4 were occasionally increased during spring after the snowmelt under specific geological conditions. The continued increase in NO3 and metal concentrations in groundwater indicates the potential contamination risk to the aquifer. Stable isotopes of δ18O and δ2H indicate groundwater recharge directly from meteoric water, with an insignificant contribution from lake water, and no seawater intrusion into the aquifer. Groundwater geochemistry suggests that local seawater intrusion is temporarily able to take place in the sulfate reduction zone along the freshwater and seawater mixed zone in the low-lying coastal area, but the contribution of seawater was found to be very low. The influence of lake water could be observed from higher levels of KMnO4 consumption in wells near the lake. The integration of PCA and HCA with conventional classification of groundwater types, as well as with the hydrogeochemical data, provided useful tools to identify the vulnerable groundwater areas representing the impacts of both natural and human activities on water quality and the understanding of complex groundwater flow system for the aquifer vulnerability assessment and groundwater management in the future.


Author(s):  
Mehmet Taşan ◽  
Yusuf Demir ◽  
Sevda Taşan

Abstract This study assessed groundwater quality in Alaçam, where irrigations are performed solely with groundwaters and samples were taken from 35 groundwater wells at pre and post irrigation seasons in 2014. Samples were analyzed for 18 water quality parameters. SAR, RSC and %Na values were calculated to examine the suitability of groundwater for irrigation. Hierarchical cluster analysis and principal component analysis were used to assess the groundwater quality parameters. The average EC value of groundwater in the pre-irrigation period was 1.21 dS/m and 1.30 dS/m after irrigation in the study area. It was determined that there were problems in two wells pre-irrigation and one well post-irrigation in terms of RSC, while there was no problem in the wells in terms of SAR. Piper diagram and cluster analysis showed that most groundwaters had CaHCO3 type water characteristics and only 3% was NaCl- as the predominant type. Seawater intrusion was identified as the primary factor influencing groundwater quality. Multivariate statistical analyses to evaluate polluting sources revealed that groundwater quality is affected by seawater intrusion, ion exchange, mineral dissolution and anthropogenic factors. The use of multivariate statistical methods and geographic information systems to manage water resources will be beneficial for both planners and decision-makers.


2021 ◽  
pp. 56-77
Author(s):  
Thyego Silva ◽  
Mariucha Lima ◽  
Teresa Leitão ◽  
Tiago Martins ◽  
Mateus Albuquerque

A hydrochemical study was conducted on the Quaternary Aquifer, in Recife, Brazil. Groundwater samples were collected in March–April 2015, at the beginning of the rainy season. Conventional graphics, ionic ratios, saturation indices, GIS mapping, and geostatistical and multivariate statistical analyses were used to water quality assessment and to characterize the main hydrochemical processes controlling groundwater’s chemistry. Q-mode hierarchical cluster analysis separated the samples into three clusters and five sub-clusters according to their hydrochemical similarities and facies. Principal Component Analysis (PCA) was employed to the studied groundwater samples where a three-factor model explains 80% of the total variation within the dataset. The PCA results revealed the influence of seawater intrusion, water-rock interaction, and nitrate contamination. The physico-chemical parameters of ~30% groundwaters exceed the World Health Organization (WHO) guidelines for drinking water quality. Nitrate was found at a concentration >10 mg NO3−/L in ~21% of the wells and exceeded WHO reference values in one. The integrated approach indicates the occurrence of the main major hydrogeochemical processes occurring in the shallow marine to alluvial aquifer as follow: 1) progressive freshening of remaining paleo-seawater accompanying cation exchange on fine sediments, 2) water-rock interaction (i.e., dissolution of silicates), and 3) point and diffuse wastewater contamination, and sulfate dissolution. This study successfully highlights the use of classical geochemical methods, GIS techniques, and multivariate statistical analyses (hierarchical cluster and principal component analyses) as complementary tools to understand hydrogeochemical processes and their influence on groundwater quality status to management actions, which could be used in similar alluvial coastal aquifers.


Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 789 ◽  
Author(s):  
Aboubacar Modibo Sidibé ◽  
Xueyu Lin ◽  
Sidi Koné

In the Sahel region in Africa, and in most arid regions, groundwater is the crucial source for water supply since surface water is scarce. This study aimed to understand a complex geochemical mechanism controlling the mineralization process in the Taoudeni Basin. A thousand randomly distributed groundwater samples acquired from different aquifers were used for this research. The results show that the majority of the samples observed are of the Ca2+-Mg2+-HCO3− and Na+-HCO3− types depending on the different aquifers. Mg2+ and Ca2+ may react with HCO3− precipitating as calcite and dolomite. The Na+-HCO3− groundwater type is mainly derived from the ion exchange process. This type indicates a paleo-marine depositional environment or that it passes through paleo-marine channels. Calcium of the standard Ca2+-HCO3− groundwater type exchanges with the sodium. Groundwater is characterized by the water-rock interactions that indicate the chemical alteration of the rock-forming minerals influencing its quality by a dissolution. The δ2H and δ18O stable isotopes designate the evaporation importance in the basin and recharge with recent rain. The bicarbonate-type presence in groundwater suggests that it is young and fresh water. Multivariate statistical methods, notably Principal Component Analysis and Hierarchical Cluster Analysis, confirm affinities among the aquifers and identify three main clusters grouped into two water types. Cluster 1 consists of Infra-Cambrian and Quaternary aquifers, whereas cluster2 includes the Precambrian basement and Permian-Triassic aquifers.


2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Abdulqadir Abubakar Usman ◽  
Murtala Abubakar Gada ◽  
Aminu Muhammad Bayawa ◽  
Ibrahim Mustapha Dankani ◽  
Saadu Umar Wali

This study examined the hydrochemistry of surface water along the River-Rima floodplain area. Five sampling locations were purposively selected, and, in each point, three samples were taken from surface water (river). The sampling was repeated after 20 days. Thus, a total of 30 samples were collected. Water samples obtained were subjected to laboratory tests. Results revealed that BOD, TDS, Mg2+, and Fe3+ are above the World Health Organization (WHO) and Standard Organization of Nigeria (SON) reference guidelines for drinking water quality. Isolates detected from the coliform bacteriological analysis include Enterobacter aerogene, Escherichia coli, and Citrobacter freundii with most of the samples showing coliform bacteria growth above the SON standard for drinking water. Hence, the water in the River-Rima floodplain of the Wamakko area is of low quality and unsafe for drinking. Results of principal component analysis (PCA) revealed external influences such as pollutant wash off and rock weathering as controls on hydrochemistry of surface water. There is some indication of anthropogenic inputs (Cl-, NO3-, and PO42-) based on hierarchical cluster analysis. Elements including Cl-, NO3-, and PO42- are increasingly added into surface water from human activities, mainly agriculture, and municipal sewage.


2020 ◽  
Vol 69 (4) ◽  
pp. 398-414 ◽  
Author(s):  
Vasant Wagh ◽  
Shrikant Mukate ◽  
Aniket Muley ◽  
Ajaykumar Kadam ◽  
Dipak Panaskar ◽  
...  

Abstract The integration of pollution index of groundwater (PIG), multivariate statistical techniques including correlation matrix (CM), principal component analysis (PCA), cluster analysis (CA) and various ionic plots was applied to elucidate the influence of natural and anthropogenic inputs on groundwater chemistry and quality of the Kadava river basin. A total of 80 groundwater samples were collected and analysed for major ions during pre- and post-monsoon seasons of 2012. Analytical results inferred that Ca, Mg, Cl, SO4 and NO3 surpass the desirable limit (DL) and permissible limit (PL) of Bureau of Indian Standards (BIS) and the World Health Organization (WHO) in both the seasons. The elevated content of total dissolved solids (TDS), Cl, SO4, Mg, Na and NO3 is influenced by precipitation and agricultural dominance. PIG results inferred that 52.5 and 35%, 30 and 37.5%, 12.5 and 20%, 2.5 and 5% groundwater samples fall in insignificant, low, moderate and high pollution category (PC) in pre- and post-monsoon seasons, respectively. PC 1 confirms salinity controlled process due to high inputs of TDS, Ca, Mg, Na, Cl and SO4. Also, PC 2 suggests alkalinity influence by pH, CO3, HCO3 and F content. PIG and statistical techniques help to interpret the water quality data in an easier way.


Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1542
Author(s):  
Kyungsun Shin ◽  
Dong-Chan Koh ◽  
Hyejung Jung ◽  
Jeonghoon Lee

The effect of seawater on the groundwater in archipelago of South Korea where it has rarely been investigated was analyzed by examining the hydrogeochemical characteristics. A total of 74 groundwater samples were classified by water quality type and Cl−/HCO3− molar ratio. First, 36 samples of the Ca–Cl type and 32 samples of the Na–Cl type (accounting for 91.9% of the total) were considered to have been influenced by seawater. When the samples had been classified based on the Cl−/HCO3− molar ratio, the samples with a Cl−/HCO3− molar ratio of 2.8 or higher (indicating that seawater had highly influenced the groundwater) accounted for 40 out of 74 samples. This confirms that the groundwater in the study area had been affected by seawater. When quantitatively determining the influence of seawater on the groundwater, the seawater mixing ratios using either Cl or Br ion were found to be almost the same. In the case of Cl ion, the mixing ratio was in the range of 0–10.4% (average of 1.0%), while when using Br ion, the mixing ratio was in the range of 0–7.6% (average of 0.6%). From a principal component analysis, it can be seen that the influence of seawater occupied the first component of 54.1% and it is evident that the samples with a large mixing ratio of seawater were from regions where seawater has a large influence. The ion-exchange reaction was proceeded by calculating the ionic delta value to indicate the seawater intrusion and cation exchange, and specific trends of the ions participating in the geochemical reaction related to the seawater mixing ratio are reported herein. It was found that the ionic delta value of each ion had a mixing ratio and specific tendency according to the change in mixing ratio before the constant value of the seawater mixing ratio saturated with Na2+. Our results show that it can be possible to grasp the contribution of the geochemical reactions of each ion to the seawater mixing ratio.


2017 ◽  
Vol 15 (4) ◽  
pp. 644-657 ◽  
Author(s):  
M. F. El-Shahat ◽  
M. A. Sadek ◽  
W. M. Salem ◽  
A. A. Embaby ◽  
F. A. Mohamed

The northwestern coast of Sinai is home to many economic activities and development programs, thus evaluation of the potentiality and vulnerability of water resources is important. The present work has been conducted on the groundwater resources of this area for describing the major features of groundwater quality and the principal factors that control salinity evolution. The major ionic content of 39 groundwater samples collected from the Quaternary aquifer shows high coefficients of variation reflecting asymmetry of aquifer recharge. The groundwater samples have been classified into four clusters (using hierarchical cluster analysis), these match the variety of total dissolvable solids, water types and ionic orders. The principal component analysis combined the ionic parameters of the studied groundwater samples into two principal components. The first represents about 56% of the whole sample variance reflecting a salinization due to evaporation, leaching, dissolution of marine salts and/or seawater intrusion. The second represents about 15.8% reflecting dilution with rain water and the El-Salam Canal. Most groundwater samples were not suitable for human consumption and about 41% are suitable for irrigation. However, all groundwater samples are suitable for cattle, about 69% and 15% are suitable for horses and poultry, respectively.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jonathan Andrade ◽  
Cristina Guimarães Pereira ◽  
Thamiris Ranquine ◽  
Cosme Antonio Azarias ◽  
Maria José Valenzuela Bell ◽  
...  

The ripening changes over time of special cheeses (Pecorino, ewes’ ripe, and Gouda) made with ewes’ milk were evaluated using FTIR/ATR spectroscopy during approximately one year. The midinfrared FTIR/ATR analyses were carried out in different ripening times between the cheese varieties and processed by means of multivariate statistical approaches. Overall, during the maturation, we observed a downward trend of the absorbance intensity of the amide group peaks (1700 to 1500 cm−1), which is linked to the breakdown of peptide bonds. Similar behavior was obtained for the lipidic region (3000 to 2800 cm−1 and 1765 to 1730 cm−1). Hierarchical cluster analysis and principal component analysis allowed the evaluation of the physicochemical changes of the cheeses. The proteolysis occurs in a fast pace during the first trimester of the ripening process, and the lipids are converted to smaller species as the times goes by. Our results indicate that infrared spectroscopy can be a useful tool in determining optimal temporal parameters in stages involving the development, production, and even a possible estimation of shelf life of cheeses.


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