scholarly journals Groundwater quality variations in Precambrian hard rock aquifers: a case study from Kerala, India

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
P. Nandakumaran ◽  
K. Balakrishnan

Abstract Analytical data of groundwater samples collected from weathered and deep fractured zones in the Precambrian charnockite aquifers in Kerala, India, have been studied to understand their hydrochemical variations and reasons thereof. Concentrations of the majority of the constituents analyzed were found to increase with increasing depth of aquifers, with the exception of nitrate. Studies indicate that various processes such as ion exchange reactions, carbonate weathering and silicate weathering are active in both the aquifers which influence the hydrochemical composition of groundwater in them. The prevailing groundwater quality in the aquifers is dependent on the dominance of each process in relation to others. Principal component analysis of the data suggests that contamination from anthropogenic sources has a major role in determining the hydrochemical characteristics of groundwater in the weathered zone unlike in the case of fractured aquifers where water–rock interaction is the major factor responsible. The study also indicates limited hydraulic connection between the weathered and fractured aquifers at the local scale.

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.


2020 ◽  
pp. 73-89
Author(s):  
Kofoworola Olatunde ◽  
Modupe Sarumi ◽  
Sadiq Abdulsalaam ◽  
Babatunde Bada ◽  
Funmilola Oyebanji

Groundwater forms a very important part of the water supply chain and its quality can be affected by improperly constructed septic tanks used by homeowners in peri-urban locations such as Abeokuta in recent times. Sixty groundwater samples collected from hand-dug wells ≤15m from septic tanks were analysed for physicochemical and bacteriological parameters using standard procedures. Results were integrated with multivariate and hydrogeochemical analyses to assess the effect improperly built septic tanks have on groundwater quality around the Federal University of Agriculture, Abeokuta. The range of values for the measured parameters include: pH (6.26 – 8.66), EC (83 – 1035 μS cm-1), TDS (42 – 621 mg L-1), Mg2+ (2 – 60 mg L-1), NO3- (5.09 – 17 mg L-1), Fe (-.04 – 5.32 mg L-1), BOD (0.1 – 13.2) and E. Coli (ND – 41×10 cfu mL-1). The abundance of major ions are in the order Ca2+˃Mg2+˃K+˃ Na+ and Cl- ˃SO42- >HCO3- >NO3- ˃PO42-. The piper trilinear plot shows that the dominant hydrochemical facies in the study area is the Ca2+–Cl- type. A correlation analysis and a principal component analysis both reflect intrusions from biological wastes such as surrounding septic tanks or municipal waste disposals as well as dissolutions from basal rocks. The possibility of infiltration from sewage into groundwater is confirmed by the number of samples with high BOD, NO3-, and E. coli concentrations. Contamination of groundwater with sewage exposes the populace to acute excreta-related illness. This therefore calls for stringent monitoring and management measures to be put in place by relevant regulatory authorities to safeguard the human health and environment within the study area.


2019 ◽  
Vol 10 (1) ◽  
pp. 22-28
Author(s):  
Sanober Rafi ◽  
Owais Niaz ◽  
Sadaf Naseem ◽  
Umair Majeed ◽  
Humaira Naz

This study is aimed to evaluate the groundwater quality of Gulshan-e-Iqbal and Liaquatabad towns inKarachi. Thirty (n=30) groundwater samples were randomly collected from different locations by electrically pumpedwells at various depths (14-91m). All the water samples were analyzed to determine their suitability for drinkingpurpose based on various physicochemical parameters. Data reveal that high concentration of TDS and hardness havedeteriorated the groundwater quality of study area. The main phenomenon responsible for groundwater pollution is theseawater intrusion due to the proximity of study area to the Arabian sea. Large scale unplanned urbanization, poorwaste management and other anthropogenic activities have also triggered the deterioration of groundwater quality.Study showed that local geology plays vital role in the distribution of major cations and anions. Data suggested thatground water of this study area is highly contaminated by seawater intrusion and considered not fit for drinkingpurpose.


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.


2018 ◽  
Vol 37 (1) ◽  
pp. 39-48
Author(s):  
Fatha Chelih ◽  
Chemseddine Fehdi ◽  
Shuhaib Khan

AbstractMorphostructural, hydrogeological and hydrochemical approaches were applied to Hammamet plain and its surrounding mountains in the eastern part of Algeria to characterize the groundwater system and its potential for exploitation. The Essen and Troubia Mountains form the natural boundaries of Hammamet plain. The objective of this study is to utilize remote sensing techniques combined with structural analysis, hydrogeology and hydrogeochemistry to identify the potential fracture zones for groundwater in the strongly fractured and karstified deep aquifers. The delineated zones of potential groundwater resources are verified by detailed hydrogeological field surveys.From a hydrogeological point of view, these two mountains, constitute a unit limited by faults oriented ENE-WSW, NNW-SSE and NNE-SSW. Specifically, fractures of the latter two directions influence the compartmentalization and the hydrogeological functioning of this unit. According to the degree of fracturing and/or karstification, two basic types of aquiferous behaviour have been distinguished: fissured aquifer (Essen Mountain and Troubia Mountain), and porous aquifer (Hammamet plain).The study of the hydrochemical characteristics of groundwater samples shows that the majority of samples are mainly of HCO3− and Ca2+ water type. The ionic speciation and mineral dissolution/precipitation was calculated with the PHREEQC software. The chemical composition of the water is influenced by the dissolution and/or precipitation processes during the water–rock interaction and by the cationic exchange reactions between groundwater and alluvial sediments. The high content of CO2 in the water samples suggests that they circulate in a geochemical open system. The isotopic analysis of some groundwater samples shows a similarity with the meteoric waters, which reflect their short residence time and a low evaporation of the infiltrated water.


2017 ◽  
Author(s):  
Dasapta Erwin Irawan

This project was originated from my PhD research project (2005-2009), which has been uploaded for sometime at Figshare.---The Mount Ciremai is a 3072 masl situated in the south of Cirebon. It constitutes of spring zones along its foot slopes with nearly 200 groundwater springs, discharging 10 L/s to 800 L/s of water. The spring zone is fed by volcanic aquifer system, which lie over clay-sand layers which contains large masses of intercalated evaporites. Due to these conditions, the hydrochemical composition of the volcanic springs is relatively variable. In this study a hydrogeochemical characterization of the aquifer is undertaken to identify the aquifer system and the shifting of pysico-chemical properties, based on 140 samples collected from the volcanic springs. The identification was performed by studying hydrographs, the temporal evolution of physico-chemical parameters, and by means of multivariate statistical analyses with ifteen (15) hydrochemical parameters were considered (pH, EC., TDS., Twater, Tair, elevation, lithology, aquifer medium, Ca, Mg, Na, K, HCO3, Cl, SO4). Principal Component Analysis (PCA) and Cluster Analysis (CA) were applied in order to examine the importance of each parameter, investigate correlations among them, and separate them into groups. CA recognizes two clusters. Cluster 1 consists of mesothermal and hypothermal waters which are circulating in the volcanic aquifer system. This cluster is divided in to Cluster 1a which consists of 131 springs, with Ca-HCO3 from plagioclase rocks and Cluster 2b constitutes 3 springs with Mg-HCO3 ferromagnesian rocks. These samples are closely related with meteoric water. Cluster 2 consists of two springs circulating in the volcanic rock aquifer system. Both springs are hyperthermal, with high Na-K-Cl and TDS/DHL contents from volcanic activities. PCA identifies the neutral parameters on Quadrant I and IV which consists of mesothermal and hypothermal groundwater samples located on higher altitude. Neutral parameters change to dominant pH, Mg, Ca, HCO3 in Quadrant III. The three quadrants are controlled by volcanic rock aquifer system with relatively fast circulation in fractured aquifers. The prevailing parameters alter to dominant TDS/EC, Na, K, Cl, and SO4 in Quadrant II which contains volcanic – hyperthermal groundwater samples. Along the direction of flow, hydrochemical trends are seen as the groundwater type changes from neutral type to Ca-HCO3, Mg-HCO3; then to Na-K-Cl derived from the mixture between cold waters and thermal water. Cibulan spring shows different pattern of groundwater and surface temperature graphs. It indicates closed aquifer system, un-associated with surface environment. More similar curve pattern is shown at Telaga Remis spring. It indicates that the groundwater flows in open aquifer system, associated with surface environment. Gradual curve indicates the control of porous aquifer system, while the sharp one indicates the role of fractured aquifers. The estimated time residence of groundwater is within 3-7 months period. The calculation of spring’s recharge area from the charts are 3725 km2 with 8.2x109 m3/year of recharge for Cibulan, 6188 km2 with 14.5x109 m3/year of recharge for Telaga Remis.The application of PCA and CA of hydrochemical and hydrodynamic data can be used to extract the conceptual model of hydrochemical evolution of volcanic waters. Moreover, the use of both approaches allows better establishment of volcanic aquifer characterization. Key word: volcanic aquifer system, physical and chemical properties, cluster analysis, principal component analysisTotal words: 500


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.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3589
Author(s):  
Javed Iqbal ◽  
Chunli Su ◽  
Abdur Rashid ◽  
Nan Yang ◽  
Muhammad Yousuf Jat Baloch ◽  
...  

Groundwater is a critical water supply for safe drinking water, agriculture, and industry worldwide. In the Khanewal district of Punjab, Pakistan, groundwater has severely deteriorated during the last few decades due to environmental changes and anthropogenic activities. Therefore, 68 groundwater samples were collected and analyzed for their main ions and trace elements to investigate the suitability of groundwater sources for drinking and agricultural purposes. Principal component analysis (PCA) and cluster analysis (CA) were employed to determine the major factors influencing groundwater quality. To assess the groundwater’s appropriateness for drinking and irrigation, drinking and agricultural indices were used. The pH of the groundwater samples ranged from 6.9 to 9.2, indicating that the aquifers were slightly acidic to alkaline. The major cations were distributed as follows: Na+ > Ca2+ > Mg2+ > K+. Meanwhile, the anions are distributed as follows: HCO3− > SO42− > Cl− > F−. The main hydrochemical facies were identified as a mixed type; however, a mixed magnesium, calcium, and chloride pattern was observed. The reverse ion exchange process helps in exchanging Na+ with Ca2+ and Mg2+ ions in the groundwater system. Rock weathering processes, such as the dissolution of calcite, dolomite, and gypsum minerals, dominated the groundwater hydrochemistry. According to the Weight Arithmetic Water Quality Index (WAWQI), 50% of the water samples were unsafe for drinking. The Wilcox diagram, USSL diagram, and some other agricultural indices resulted in around 32% of the groundwater samples being unsuitable for irrigation purposes. The Khanewal’s groundwater quality was vulnerable due to geology and the influence of anthropogenic activities. For groundwater sustainability in Khanewal, management strategies and policies are required.


2019 ◽  
Vol 98 ◽  
pp. 01047
Author(s):  
Fahad Souid ◽  
Peter Birkle ◽  
Fred Worrall

A total of 79 groundwater samples from the Upper Silurian-Lower Devonian Tawil and Triassic Jilh aquifers in NW Saudi Arabia were analysed for hydrochemical and strontium isotopic composition. A sequential extraction and 87Sr/86Sr analysis were conducted on 32 cutting samples from the groundwater host rocks and the underlying shale bed. The chemical composition of the groundwater was distinct from that of the host rock lithologies in terms of elemental abundance (i.e., Na+ was dominant in the groundwater and K and Ca were the main constituents of the aquifer units). Principal component analysis (PCA) of water samples showed a positive loading of Na+ and negative loadings of Ca2+ and SO42-. The replacement of gypsiferous waters by Na+-rich waters is suggested by this ion exchange. The shale rock samples showed Na to be the dominant chemical constituent. 87Sr/86Sr ratios of the groundwater (0.707673-0.711577) and host rock samples (0.707930-0.712477) suggest that groundwater inherits the Sr signature of the rock from the exchangeable, carbonate, and the oxides phase, reflecting reducing conditions in Tawil aquifer. The elevated groundwater 87Sr/86Sr ratios were found in deeper sections of the aquifers, which coincided with the radiogenic 87Sr/86Sr of the deeper aquifer lithologies and the underlying shale bed.


Author(s):  
Sanober Rafi ◽  
Owais Niaz ◽  
Sadaf Naseem ◽  
Umair Majeed ◽  
Humaira Naz

This study is aimed to evaluate the groundwater quality of Gulshan-e-Iqbal and Liaquatabad towns inKarachi. Thirty (n=30) groundwater samples were randomly collected from different locations by electrically pumpedwells at various depths (14-91m). All the water samples were analyzed to determine their suitability for drinkingpurpose based on various physicochemical parameters. Data reveal that high concentration of TDS and hardness havedeteriorated the groundwater quality of study area. The main phenomenon responsible for groundwater pollution is theseawater intrusion due to the proximity of study area to the Arabian sea. Large scale unplanned urbanization, poorwaste management and other anthropogenic activities have also triggered the deterioration of groundwater quality.Study showed that local geology plays vital role in the distribution of major cations and anions. Data suggested thatground water of this study area is highly contaminated by seawater intrusion and considered not fit for drinkingpurpose.


Sign in / Sign up

Export Citation Format

Share Document