Sabarathinam Chidambaram | Kuwait Institute for Scientific Research (KISR) (original) (raw)

Papers by Sabarathinam Chidambaram

Environmental Monitoring and Assessment

Hydrological Processes

A reasonable estimation of aquifer recharge can assist in the sustainable management of groundwat... more A reasonable estimation of aquifer recharge can assist in the sustainable management of groundwater resources. The methodology to calculate aquifer recharge presents many challenges due to geological complexity and the existence of different water qualities in the aquifer. The classic chloride mass balance (CMB) method has been used widely for aquifer recharge estimation but the assumptions in the equations neglect other sources of chloride than rainfall; chloride accumulation due to evaporation and the hydraulic properties of the recharged aquifer. This research aims to introduce modifications and derive a new CMB equation that covers the shortcomings in the earlier classic CMB approach. The newly developed approach was verified mathematically to identify the sensitive parameters that affect the results of aquifer recharge. Also, it was verified by independent data and method (groundwater modelling) and showed that it is approaching reality about recharge estimation than the earlie...

Marine Pollution Bulletin, 2022

The dynamics of the coastal aquifers are well-expressed by geochemical and isotopic signatures. C... more The dynamics of the coastal aquifers are well-expressed by geochemical and isotopic signatures. Coastal regions often exhibit complex groundwater recharge pattern due to the influence of depression in the Bay of Bengal, tidal variations on surface waters, saline water intrusion and agricultural return flows. In this research, groundwater recharge processes occurring in coastal Tamil Nadu, South India were evaluated using major ion chemistry and environmental isotopes. A total of 170 groundwater samples were collected from shallow and deep aquifers during both post-monsoon (POM) and pre-monsoon (PRM) seasons. The isotopic results showed a wide variation in the shallow groundwater, suggesting contribution from multiple recharge sources. But, the deeper groundwater recharge is mainly from precipitation. The northern part of the study area showed more depleted isotopic values, which rapidly changed towards south from -6.8 to -4.4‰. Alternatively, central and southern parts exhibited relatively enriched isotopic content with variation from -0.58 to -2.7‰. Groundwater was discerned to be brackish to saline with chloride content, 600-2060 mgL-1 and δ18O ranging from -5.8 to -4.5‰, suggesting influence of the saline water sources. A minor influence of anthropogenic activities was also observed in the deeper groundwater during PRM, which was confirmed by tritium and Cl- trends. The old groundwater with depleted isotopic content infer recharged by distant sources while modern groundwater with enriched isotopes points to the influence of evaporated recharge.

Environment, Development and Sustainability, 2021

Geo-electrical survey was conducted in a highly industrialized area to delineate the freshwater a... more Geo-electrical survey was conducted in a highly industrialized area to delineate the freshwater and saline water aquifers. A total of 30 vertical electrical soundings (VES) were made along the coastal aquifers of Tuticorin, which covers both sedimentary formation and crystalline rocks. By using VES data, GIS was used to create spatial maps for resistivity and thickness at various depths. The results show that Q and H were the dominant curve types in the study area. Q type curves indicate saline water by decreasing resistivity values with respect to depths. In H type curves, low resistivity saline water aquifer was sandwiched between high resistivity topsoil and hard rock at the deeper horizon. The geophysical indicators such as Dar-Zarrouk parameters were calculated using the VES results. The Longitudinal unit conductance (S) values ranged between 0.075 and 7500 S. The transverse unit resistance (T) of the study area varied from 16.06 to 5909.25 Ωm2. The anisotropy (λ) values ranged from 1.00 to 55. Interpretation of data reveals that the saline water intrusion and industrial impact on shallow aquifers were observed in the coastal region of the study area. Few pockets of the freshwater aquifer were also noted in deeper horizons. Since the quality of groundwater was deteriorating, proper management plans will be needed to save this fragile coastal aquifer.

Journal of Hydrology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Arabian Journal of Geosciences, 2020

Groundwater is the most important natural resource around the world which needs new and advanced ... more Groundwater is the most important natural resource around the world which needs new and advanced technologies for control and monitoring. This investigation was to check the groundwater potential zones by integrated techniques of geoinformatics and geophysical investigation through a vertical electrical sounding in Rawalakot, Azad Kashmir, Pakistan. The study area being a sedimentary basin, sandstone is the major rock type with good porosity and permeability. Satellite data were used to generate different thematic maps such as slope percent, lineament density, land use/cover, drainage density, geology, roughness index, curvature, topographic wetness index, and rainfall. Subsequently suitable rank and weightage was assinged for final weight overlay analysis to identify the groundwater potential zones. Final potential map was generated with good, moderate, and poor zones. This analysis revealed that 92.60% of the area is categorized to be having good to moderate groundwater potential. Then, an electrical resistivity survey was done by vertical electrical sounding (VES) using Schlumberger electrode configuration, at 32 locations to check the subsurface condition. The predominant curve types were Q type, A type, H type, and K type. The apparent resistivity was calculated at 20-m, 40-m, and 60-m depths. Dar-Zarrouk parameters were calculated to identify the subsurface aquifers and protective capacity rating. Integrating the outcome of GIS and geophysical studies, the region with good groundwater potential was delineated with more accuracy.

Geochemistry, 2019

A study has been carried out in KT (Cretaceous-Tertiary) boundary along the contact zones of hard... more A study has been carried out in KT (Cretaceous-Tertiary) boundary along the contact zones of hard rock, limestone and sedimentary formations to discern the geochemical processes governing the groundwater chemistry. A total of sixty-three groundwater samples were collected from the handpumps covering the entire study area and measured for hydrochemical species. Principal component analysis of the hydrochemical data inferred three major processes governing the geochemistry of the groundwater of the region as leaching, ion exchange and weathering. It was also inferred that there are few samples depicting the mixtures of these processes (what are they mention it) and few samples not representing any of these processes with adequate statistical significance. Hence, in order to know the geochemical behaviour of the samples representing each process, their combinations along with the samples which are not-representative samples of these processes were inferred using various standards plots to get an insight into their geochemical characteristics and affinity. This also inferred the samples representing different processes have a significant signature of geochemical facies. The major ions and the stable isotopes of groundwater were used to understand these processes. The carbonate and sulphate saturation states of these samples were calculated by PHREEQC and compared with major variations with the identified three geochemical processes. The state of saturation of Halite, Anhydrite, Gypsum, Aragonite, Dolomite, Calcite, Talc and Chrysolite were determined in all the samples. Inverse modeling was carried out considering the non-representative samples as initial solution and the samples representing each factor as final solution to understand the phase mole transfer in each process. An attempt was also made in this study to compare the geochemical behaviour of groundwaters from different KT boundaries. The samples representing these processes were plotted on an integrated map representing lithology, lineaments, drainage and elevation to determine their interrelationships. The study groups the samples into anthropogenic or geogenic. The leaching process is controlled by lithology and landuse, ion exchange processes is influenced by lithology and drainage patterns whereas weathering processes were controlled by lithology, drainage and lineaments. Non representation of samples (NRS) were mainly controlled by drainage and lineaments of the region.

Environmental Earth Sciences, 2012

ABSTRACT Fluoride (F−) is an indispensable element for the human’s skeletal and dental health at ... more ABSTRACT Fluoride (F−) is an indispensable element for the human’s skeletal and dental health at prescribed levels and becomes lethal at higher levels. Spatial–temporal variability of F− and its geochemical control/association with other dissolved ions in groundwater in the Dindigul district of Tamilnadu (India) were conducted to describe the geochemical dynamics of F– in response to seasonal variability. High concentrations of fluoride (≥1.5 mg L−1) were observed in the northern region of the district. High levels of F− were observed in non-monsoon periods and low levels in monsoon, because of dilution by precipitation. Bicarbonate was well correlated with F− which explains that both ions were derived from the weathering. While F− has a very weak correlation with silica, this implies that the silicate weathering does not supply F− to the groundwater system. The F− pollution in Dindigul groundwaters is mainly driven by two factors: (1) the geogenic weathering inputs, the geology of this area mainly comprises fluoride bearing minerals (e.g. hornblende biotite gneiss and charnockite); (2) the anthropogenic inputs (agri-fertilizers and tannery waste). Further, F− in the study area is mainly attributed to geogenic sources during pre and postmonsoons and anthropogenic sources in monsoon periods.

Environmental Earth Sciences, 2013

ABSTRACT Groundwater from 47 wells were analyzed on the basis of hydrochemical parameters like pH... more ABSTRACT Groundwater from 47 wells were analyzed on the basis of hydrochemical parameters like pH, electric conductivity, total dissolved solids, Ca2+, Mg2+, Na+, K+, Cl−, CO32−, HCO3−, NO3−, PO43− and F− in the Cauvery delta of Vedaraniyam coast. Further, water quality index (WQI), sodium percentage (Na %), sodium absorption ratio, residual sodium carbonate, permeability index and Kelley’s ratio were evaluated to understand the suitability of water for drinking and irrigation purposes. The result shows significant difference in the quality of water along the coastal stretch. The order of dominance of major ions is as follows: Na+ ≥ Mg2+ ≥ Ca2+ ≥ K+ and Cl− ≥ HCO3− ≥ CO32− ≥ PO43− ≥ F−. Na/Cl, Cl/HCO3 ratio and Revelle index confirmed that 60–70 % of the samples were affected by saline water intrusion. WQI showed that 36 % of the samples were good for drinking and the remaining were poor and unsuitable for drinking purpose. The degradation of groundwater quality was found to be mainly due to over-exploitation, brackish aquaculture practice, fertilizer input from agriculture and also due to domestic sewage.

Journal of the Geological Society of India, 2011

The groundwater quality detoriation due to various geochemical processes like saline water intrus... more The groundwater quality detoriation due to various geochemical processes like saline water intrusion, evaporation and interaction of groundwater with brines is a serious problem in coastal environments. Understanding the geochemical evolution is important for sustainable development of water resources. A detailed investigation was carried out to evaluate the geochemical processes regulating groundwater quality in Cuddalore district of Tamilnadu, India. The area is entirely underlined by sedimentary formations, which include sandstone, clay, alluvium, and small patches of laterite soils of tertiary and quaternary age. Groundwater samples were collected from the study area and analyzed for major ions. The electrical conductivity (EC) value ranged from 962 to 11,824 μS/cm, with a mean of 2802 μS/cm. The hydrogeochemical evolution of groundwater in the study area starts from Mg-HCO 3 type to Na-Cl type indicating the cation exchange reaction along with seawater intrusion. The Br/Cl ratio indicates the evaporation source for the ion. The Na/Cl ratios indicate groundwater is probably controlled by water-rock interaction, most likely by derived from the weathering of calcium-magnesium silicates. The plot of (Ca+Mg) versus HCO 3 suggests ions derived from sediment weathering. The plot of Na+K over Cl reflects silicate weathering along with precipitation. Gibbs plot indicates the dominant control of rock weathering. Factor analysis indicates dominance of salt water intrusion, cation-exchange and anthropogenic phenomenon in the study.

Environmental Monitoring and Assessment, 2009

Natural hazards cause great damage to humankind and the surrounding ecosystem. They can cast cert... more Natural hazards cause great damage to humankind and the surrounding ecosystem. They can cast certain indelible changes on the natural system. One such tsunami event occurred on 26 December 2004 and caused serious damage to the environment, including deterioration of groundwater quality. This study addresses the groundwater quality variation before and after the tsunami from Pumpuhar to Portnova in Tamil Nadu coast using geochemical methods. As a part of a separate Ph.D. study on the salinity of groundwater from Pondicherry to Velankanni, water quality of this region was studied with the collection of samples during November 2004, which indicated that shallow aquifers were not contaminated by sea water in certain locations. These locations were targeted for post-tsunami sample collection during the months of January, March and August 2005 from shallow aquifers. Significant physical mixing (confirmed with mixing models) within the aquifer occurred during January 2005, followed by precipitation of salts in March and complete leaching and dissolution of these salts in the post-monsoon season of August. As a result, maximum impact of tsunami water was observed in August after the onset of monsoon. Tsunami water inundated inland water bodies and topographic lows where it remained stagnant, especially in the near-shore regions. Maximum tsunami inundation occurred along the fluvial distributary channels, and it was accelerated by topography to a certain extent where the southern part of the study area has a gentler bathymetry than the north.

Environment, Development and Sustainability, 2013

The groundwater occurs in hard rock aquifers, which is more predominant in India. It is more comm... more The groundwater occurs in hard rock aquifers, which is more predominant in India. It is more common in the southern peninsula especially Tamil Nadu. Madurai district is located in the central part of Tamil Nadu, underlain predominantly by crystalline formations and alluvium along the river course. The study area being a hard rock terrain, the groundwater is stored in cracks, fissures, joints, etc., and hence the quantity is lesser. The frequent failure of monsoon also aggravates the scarcity of this commodity. In this scenario, the quality and hydrogeochemistry of the available quantum of water plays a significant role for the determination of its utility and in tracing out the hydrogeochemical evaluation. Fifty-four groundwater samples were collected representing the entire study area. The samples collected were representative covering all the major litho units of the study area (charnockite-21, fissile hornblende biotite gneiss-21, granite-4, quartzite-3, and 5 samples from flood plain alluvium). The samples collected were analyzed for major ions and were classified for different purposes like drinking, domestic, and agriculture, with

Arabian Journal of Geosciences, 2011

A hydrogeochemical investigation was conducted in a coastal region of Cuddalore district to ident... more A hydrogeochemical investigation was conducted in a coastal region of Cuddalore district to identify the influence of saltwater intrusion and suitability of groundwater for domestic and agricultural purposes. The geology of the study area comprises of sandstone, clay, alluvium, and laterite soils of Tertiary and Quaternary age. A total of 18 groundwater samples were analyzed for 14 different water quality

Arabian Journal of Geosciences, 2010

Abstract The accurate information through water quality analysis, scientific study on F− distribu... more Abstract The accurate information through water quality analysis, scientific study on F− distribution in ground-water and geochemical knowledge with spatial informa-tion on geology and climate are necessary to understand the source/cause, type and level of F− contamination. The ...

Arabian Journal of Geosciences, 2013

A study was carried out in the Madurai district of Tamil Nadu, India to identify the hydrogeochem... more A study was carried out in the Madurai district of Tamil Nadu, India to identify the hydrogeochemical processes using factor analysis as a predictive tool. It also focuses on characterizing the samples of these factors with respect to standard geochemical plots. In order to obtain a synoptic view of the statistics and the geochemical processes, a total of 53 groundwater samples are collected representing the entire district. The major ions were analyzed; the order of ion dominance are Ca 2+ >Na + >Mg 2+ >K + =Cl − >HCO − 3 >H 4 SiO − 4 > NO − 3 >SO 2− 4 >P 3− 4. The samples are classified according to three factors. Factor 1 shows strong positive loadings of Cl − , Ca 2+ , Mg 2+ , and NO − 3 with 36.98 % of the total variance (TV); factor 2 accounts for 13.72 % of TV with high loadings of Na + , K + , and HCO − 3 ; and factor 3 shows strong positive loadings of PO 3− 4 and SO 2− 4 with TV of 13.1 %. In the Piper plot, few samples fall in the mix region as evidenced by the mixing proportion of two samples using AQUACHEM software. The results suggest that different hydrogeochemical processes, like weathering, ion exchange processes, and anthropogenic activities (like sewage infiltration and agriculture), has predominant impact in the study area. Thus, the study highlights the factor analysis technique as a predictive and effective tool for groundwater evolution.

The ground water in a particular coastal aquifer is to be described, evaluated and explained prim... more The ground water in a particular coastal aquifer is to be described, evaluated and explained primarily by application of principles of aquatic chemistry to hydrogeological systems to understand the migration of solutes using field data. The origin of salinity is not only due to seawater intrusion but there are other possible sources. There is a lot of human pressure on the coast line due to urbanization, industrialisation, aquacultural and agricultural activities. Apart from these factors, salinity increase in the coastal aquifers, sea level changes, changes in coastal configurations due to mining activities and impact of the natural calamities like floods, tsunami and earth quake also add to the magnitude of the problem. This study aims to bring out the Land use/land cover pattern of study area were studied using IRS P6 LISS III data and correlate with the water level, Electrical conductivity of ground water and rainfall variations. Two data products were selected during May 2000 and august 2009 to study the land use pattern variations. The land use/land cover patterns were visually interpreted and digitized using ERDAS IMAGINE, MapInfo and Arc GIS software. The study reveals that the agricultural area has increased by 172sq.km and settlements by 28.5 sq. km there is a decrease in water bodies and others (includes waste land).

Sustainability

Sustainable management of water resources is a daunting challenge, especially with respect to mic... more Sustainable management of water resources is a daunting challenge, especially with respect to microbes. This study primarily focused on the development of a novel application for the removal of specific bacterial groups in different water types using a green synthetic nano Cur-Zn(II) complex. The results of UV and FT-IR spectroscopic techniques suggested the formation of a chelation complex. Proton NMR showed that the main enolic proton peak with a chemical shift of 16.45 nm identified in curcumin was missed, indicating the contribution of carbonyl oxygen of enol in the formation of the complex. The crystalline nature of the complex and Wurtzite structure of annealed products was inferred from the XRD analysis data. SEM results confirmed the complex’s morphology as spherical and clustered with a rough surface, having an average particle size of 68.2 nm. In addition, the complex was observed to be stable up to 300 °C without any decomposition from STA. Being acidic in nature with a p...

Environmental Science and Pollution Research, 2022

The study aims to determine the impact of global meteorological parameters on SARS-COV-2, includi... more The study aims to determine the impact of global meteorological parameters on SARS-COV-2, including population density and initiation of lockdown in twelve different countries. The daily trend of these parameters and COVID-19 variables from February 15th to April 25th, 2020, were considered. Asian countries show an increasing trend between infection rate and population density. A direct relationship between the time-lapse of the first infected case and the period of suspension of movement controls the transmissivity of COVID-19 in Asian countries. The increase in temperature has led to an increase in COVID-19 spread, while the decrease in humidity is consistent with the trend in daily deaths during the peak of the pandemic in European countries. Countries with 65°F temperature and 5 mm rainfall have a negative impact on COVID-19 spread. Lower oxygen availability in the atmosphere, fine droplets of submicron size together with infectious aerosols, and low wind speed have contributed to the increase in total cases and mortality in Germany and France. The onset of the D614G mutation and subsequent changes to D614 before March, later G614 in mid-March, and S943P, A831V, D839/Y/N/E in April were observed in Asian and European countries. The results of the correlation and factor analysis show that the COVID-19 cases and the climatic factors are significantly correlated with each other. The optimum meteorological conditions for the prevalence of G614 were identified. It was observed that the complex interaction of global meteorological factors and changes in the mutational form of CoV-2 phase I influenced the daily mortality rate along with other comorbid factors. The results of this study could help the public and policymakers to create awareness of the COVID-19 pandemic.

Journal of Earth System Science, 2019

Sustainable groundwater management of an extreme climatic region is very important from both soci... more Sustainable groundwater management of an extreme climatic region is very important from both social and economic point of view. This study attempts to delineate the groundwater potential zones of Sonepur district, Odisha, which falls under an extreme climatic region, using remote sensing, geographical information system and Saaty's analytical hierarchy process (AHP). Different ancillary data, multiple data sets obtained from LANDSAT 8 OLI and ASTER Level-1T were used in conjunction with Cartosat-1 imagery to study the detailed physical attributes of the study area and to prepare the groundwater prospect map using a weighted overlay method in ArcGIS 10.4 software. The AHP technique was used for determining the weights of each layer. From the groundwater prospect map, it was found that 52% of the area belongs to the moderate groundwater prospect zone followed by good to very good, very good to excellent (32%) and poor (16%) groundwater prospect zones. Statistical analysis of the number of existing wells in each of these water potential zones and their water level was used to verify the accuracy of the water potentiality estimated in this study. The groundwater potentiality map prepared as a part of this study would serve as an important tool for identifying suitable zones for rainwater harvesting and also for managing groundwater abstraction for a safe and sustainable water supply.