Elango Lakshmanan

Anna University, Chennai · Department of Geology

The presence of uranium in groundwater is a cause of concern all over the world. In mineralized regions where elevated concentrations of uranium are possible in groundwater, mining activities can further degrade the water quality. Hence, it is essential to document the baseline uranium concentration in groundwater before the commencement of mining....

Fluoride contamination in drinking water is a serious public health concern across the world, and more than 90 million people in India are affected by health risks associated with fluoride. Though the fatality due to fluoride chronic toxicity is uncommon, the exposure to fluoride at different concentration levels shows various adverse health effect...

Climate change and the increase of agricultural production affects coastal aquifers around the world. Groundwater is the major source of irrigation in most of the coastal parts of India. Seawater intrusion is affecting the area just north of Chennai city as a result of over-extraction of groundwater for agricultural and drinking water supply to Che...

Increasing urbanisation and dependency on groundwater in the coastal regions has increased the vulnerability of the coastal aquifer to seawater intrusion. The objective is to understand the variation in vulnerability to seawater intrusion with response to change in groundwater level in the coastal region of Sankaraparani river basin located in the...

The objective of this study is to assess the impact of climate change induced rainfall, sea level rise, and urbanization on a fragile coastal aquifer. This study was carried out in one such an aquifer located in Southeast India. Downscaled climate projection was carried out using the regional climate model (RCM) with seven ensembles and the best ma...

Assessment of groundwater chemistry of a region is important to determine its usability. The objective of this study is to understand the hydrochemistry and groundwater quality especially with respect to fluoride in the Perambalur District, Tamil Nadu, India where groundwater is used without treatment for drinking and agricultural purposes. Groundw...

Overextraction of groundwater from coastal aquifers results in seawater intrusion causes immense threat to groundwater resources. The objectives of this study are to delineate the coastal regions affected by seawater intrusion along the east coast of India and to estimate the quantum of groundwater resources affected by seawater intrusion. The grou...

Groundwater is vital in Chennai Metropolitan Area, and thus its sustainable management is essential. This study aims to estimate groundwater recharge in the Chennai River basin (CRB) using an empirical method, a rainfall infiltration factor (RIF) method, a geographical information system (GIS)-distributed model, and the water table fluctuation (WTF...

Human civilisation has evolved generally along the banks of rivers in most of the regions around the world. Over the years, the population living along the rives have grown rapidly and several such regions have been highly urbanised. Further, several industries requiring a large amount of water are also located along the rivers. These activities al...

Groundwater depletion is one of the most critical concerns for users and policymakers. Identifying groundwater potential (low to high) helps properly plan the available groundwater resource. This study has used the possibilities of a geographical information system (GIS), remote sensing and, of course, field data to delineate the groundwater potent...

The surface water is a significant feature in the hydrological system and is a vital compound for life growth. Assessment of trace elements in the water bodies is essential since it poses huge threats to aquatic organisms and humans if present in high concentrations. This study was carried out to assess the seasonal changes in the dissolved trace e...

Groundwater recharge estimation is essential for sustainable water management and water supply schemes. In this paper, we review groundwater recharge estimation techniques and identify the appropriate methods by considering India’s hydrological and climatic conditions. Significant components of recharge, factors affecting groundwater recharge, aqui...

A three-dimensional variable-density finite element model was developed to quantify the impact of groundwater over use on submarine groundwater discharge (SGD). The model was applied to the Arani-Korttalaiyar river basin, north of Chennai, India. This region has an upper unconfined and lower semi-confined aquifer extending up to 30 km inland from t...

The present research deals with the Risk assessment of groundwater quality around 15 km radius surrounding SIPCOT industrial estate, Perundurai, Erode district. It is sub-divided into three segments with radius of 5 km each. 79 groundwater samples were collected from domestic and agricultural usage open and bore well points equally distributed (eac...

Uranium naturally occurs in groundwater and its concentration is mostly controlled by the geology of an area. The regular human consumption of groundwater with uranium causes health effects and hence the assessment of radiological and chemical toxicity effects on humans is essential. Hence, the present study was carried out to assess the general hy...

The objective of this research is to investigate the best management options for mitigating seawater intrusion through real-time coupling between rainfall–runoff, infiltration, surface water and groundwater system. The amount of runoff and discharge from sub-catchment after rainfall was first simulated by the rainfall–runoff model. This simulated d...

Rivers engage in carbon cycle by transporting the dissolved products of weathering of rocks to the oceans, and this process is sensitive to the global climatic changes. The present study was carried out with an objective of estimating the spatial and temporal variation in carbon consumption due to rock weathering in Cauvery, which is a major non-pe...

The DRASTIC index, used to assess the vulnerability of aquifers to contamination, has been subject to various adjustments to improve its reliability. These adjustments include adding and/or eliminating certain aquifer factors and modifying the factor weights. Nonetheless, there is no consensus about which factors, or their respective weights, are m...

Multi-layered coastal aquifers are complex aquifer systems with two or more aquifers divided by the impermeable or semi permeable layers. The objective is to assess the interaction between the aquifers using geochemical indicators in the urbanised multi-layered coastal aquifer of Sankaraparani river basin, India. Hydrogeologically, the coastal part...

The purpose of this study is to understand the impact of coastal groundwater over-exploitation on the variations in submarine groundwater discharge (SGD) flux rate and seawater exchange flux across the seabed. As a case study, numerical modelling techniques were applied to a complex multi-aquifer system located north of Chennai, India, which has be...

Assessment of rainfall variability and drought is essential to address the existing water crisis and water resources management. This study was carried out to assess the rainfall variability, meteorological drought and relative response of a water supply reservoir located in Chennai Metropolitan, India. Spatial and temporal variation of rainfall an...

Land use/land cover in coastal regions of large cities is affected due to rapid urbanization and industrialization. Chennai, a coastal city of Tamil Nadu, India, has witnessed tremendous changes in land use/land cover over the past two decades. Post-classification correlation change detection method was used to identify the changes over the decade....

Disposal of industrial waste is of great concern because it releases toxic metals resulting into the degradation of environments and consequently causes health effects on humans. The present study was carried out with the objectives of identifying the possible source and migration of contaminants in the surface water and groundwater and the associa...

Spatial and Temporal Variations in Geochemistry of Cauvery River Sediments (Tamilnadu, India): Indicators of Provenance and Weathering

South-West (SW), North-East (NE) and Post-monsoon Cauvery River sediment geochemistry characterizes the intensity of chemical weathering ascribing to the relative mobility of elements during weathering. The negative correlation between Al2O3% and SiO2% signifies that the sediments are enriched with quartz and, Al2O3% vs. TiO2% relationship deduces...

A well-designed environmental monitoring plan is essential for safety of uranium mining and processing operations. Evaluating the possible uncertainties in a numerical model helps in enhancing the model output and also increases the reliability over the model results. For a radionuclide transport model, distribution coefficient is a sensitive param...

The groundwater over pumping induced land subsidence is one of the major geological hazards in the alluvial aquifers. The objective of this study is to assess the rate of land subsidence in Kolkata metropolitan area, India. Land subsidence can be estimated with high precision by Small Baseline Subset (SBAS) analysis. The advantages of this method a...

The deterioration of groundwater quality has become a serious problem for the safe drinking water supply in many parts of the world. Along coastal aquifers, the saline water moves landward due to several reasons even though significant rainfall is available. The objective of the present study is to investigate the impact of a combined recharge stru...

This study integrates the time series of satellite data, i.e. (terrestrial water storage (TWS) extracted from Gravity Recovery and Climate Experiment (GRACE), soil moisture (SM) from Global Land Data Assimilation System (GLDAS), rainfall from Tropical Rainfall Measuring Mission (TRMM)) with in-situ data, i.e. (groundwater (GW) observatory well data...

The origin of groundwater and the processes controlling its chemical composition in complex coastal aquifers is of interest, as about 44% of the world’s population live in coastal areas. Groundwater over-exploitation in the highly urbanized coastal regions has exerted pressure on these aquifers leading to seawater intrusion. This study aimed to ide...

Groundwater quality and its suitability for drinking and irrigation uses were assessed and multivariate statistical analysis were applied to understand the chemical characteristics of groundwater in the upper part of Luvuvhu sub-catchment in Limpopo, South Africa. The groundwater samples collected during August 2015 (n = 41) and November 2016 (n =...

Identification of groundwater recharge zones in an area is important to properly utilize and safeguard the groundwater resources. The objective of this study is to delineate the groundwater potential zones in the Chinnar River basin of Perambalur district, southern India, using remote sensing and GIS methods. Toposheets and satellite imageries were...

The collapse of a submerged granular pile under the action of the gravity force is investigated by means of a depth averaged model (hereinafter DAM). The granular pile is a mixture of solid particles and ambient liquid, totally covered by a layer of ambient liquid. The DAM is obtained by depth-averaging the mass and momentum equations of the mixtur...

Increasing water demand and climate change poses a great challenge in managing water resources availability. Reservoir operation during heavy rainfall events in an urbanized region is crucial in terms of decision making. The objective of this study is to assess the significance of reservoir operation during extreme rainfall events on flood mitigati...

Seawater intrusion and submarine groundwater discharge are the contrary processes which plays important role in management of groundwater in coastal regions. A study was carried out to identify the seawater intrusion and submarine groundwater discharge zones along the coast of South Chennai. Groundwater samples and porewater samples were collected...

Remote sensing, geophysical, geological and hydrogeological methods were used to characterise the aquifer of a proposed uranium mining and tailings pond area in India. Examination of lithologs show uranium occurrence at the Eparchaean unconformity at a depth of about 50 to 60 m below the surface. Resistivity studies showed four distinct zones- top...

The hydrogeology of India represents one of the diverse systems in the world. The hydrologically distinct Himalayan highlands and its foreland basins with deposits of indo-Ganga Brahmaputra system gradually merges with the cratonic provinces of central and south India, fluvioaeolian deposits of west and the basaltic province of the Deccan plateau....

Extreme rainfall events in an urban area pose various challenges to the water resource managers in terms of flood mitigation, inundation, water conservation and harvesting for drinking water supply. The objective of this study is to apply the box-model approach to evaluate reservoir operation during extreme rainfall events. A large water supply res...

Intrusion of seawater into the coastal aquifers is a major concern as it affects the quality of groundwater. The objective of this study is to delineate the extent of seawater intrusion in the Indian coast based on previous studies and estimate the area as well as locations of seawater intrusion and submarine groundwater discharge based on the grou...

Uranium is a long lived radioactive element which is naturally present in minute concentrations in igneous, sedimentary and metamorphic rocks. These rocks when subjected to weathering results in the formation of soil which also has traces of uranium. Distribution coefficient (Kd) is a crucial parameter in environmental assessment which is used to p...

The origin and salinization of groundwater in multi layered coastal aquifer of Sankaraparani river basin, India was studied using isotopes and geochemical signatures. Groundwater in this region occurs in shallow unconfined and deep confined aquifers. The shallow aquifer comprises of Quaternary Alluvium whereas the deeper aquifer comprises of Tertia...

The present study focuses on the exploration of groundwater potential zones in Vellore district, Tamil Nadu, India based on geospatial technologies. Various thematic layers such as landuse/ land cover, soil texture, slope, geology, geomorphology, drainage and lineament density, rainfall, transmissivity, permeability and specific capacity were deriv...

The publisher regrets that the original version of this article contained errors. Figures 7 to 10 were shown in the wrong version, thus corrected figures are shown in this article. The original article has been corrected.

The chapter discusses the power of GIS as a tool to develop solutions for groundwater resource problems and presents applications of GIS and geostatistical techniques in various field such as science, engineering, planning, and resource management. The modern applications of GIS and statistical approaches can be used to study issues in groundwater...

Groundwater storage augmented by Managed Aquifer Recharge methods in a region will help to manage water supply when there is insufficient availability surface water. The present study was carried out to use the stable isotopes of oxygen and hydrogen to study the interaction between the surface and groundwater at Managed Aquifer Recharge (Check dam)...

A polydisperse shallow mixture consisting of Np solid phases (Np ≥ 1) and one fluid phase (the ambient fluid) is a reliable model for several industrial and environmental flows, as e.g. landslides, avalanches, debris flows and fluidized beds. The description and prediction of these flows is of primary importance, mainly with respect to the mitigati...

Virtual water (VW) is defined as the water required in the production of goods. The objective of the study is to quantify the temporal variation in the virtual water trade in India from the year 2006–2016 through popular food and livestock products. Water management issues need to consider the VW trade since food production consumes large amount of...

Ground water is the major source of drinking water in India. Over exploitation of this water resource has exacerbated the situation of providing good quality water, due to the presence of major ions, minor ions, trace elements and radioactive elements. A study has carried out in Vellore, a city in the Northern part of the Tamilnadu, to understand t...

Exploring the status of groundwater in terms of its potentiality is of serious concern, owing to its vital use for domestic, agricultural, and industrial requirements all over the world. The aim of this paper is to assess the groundwater potentiality in Rasipuram taluk, Tamil Nadu, India by combining the geospatial techniques like geographical info...

Groundwater recharge is affected by the entrapment of air in the unsaturated zone. During the infiltration process, air phase moves ahead of the wetting front and confined air mass resists wetting front propagation. This study aims at assessing the feasibility of improving groundwater recharge by providing ventilation in the unsaturated zone throug...

The interaction between surface water and groundwater is a complex process and is considered as an important component for controlling the mining activities. The objective of this study is to understand the interaction between surface water and groundwater around a proposed uranium mining site by geochemical modelling. Surface water and groundwater...

A rise in sea level is the most important threat to the coastal aquifers in which the intensity of threat also depends on the local hydrogeological settings. The present study seeks to identify the impacts of sea level rise and tidal effects on the shallow and complex aquifer located south of Chennai, India. The aquifer geometry is isolated dune su...

Groundwater is a major source of providing water which is intensively exploited for domestic, industrial, and agricultural purposes in many places of the world. In India, groundwater is getting contaminated due to geogenic and anthropogenic sources. There are increasingly widespread indicators of degradation in the quality and quantity of groundwat...

The objective of this study is to develop a Fluoride Index for mitigation of geogenic contamination by Managed Aquifer Recharge (FIMAR). This index was tested by applying to the Pambar river basin in southern India. About 40% of the study area had fluoride >1.5 mg/L, contributed from the dissolution of fluorite, fluorapatite, biotite and hornblende...

This study investigates the contamination of groundwater by chromium and fluoride around leather tanning industries. Major ions, chromium, δ⁵³Cr/δ⁵²Cr and fluoride were analyzed by advanced analytical methods. High degree of variation was observed in the concentration of chloride in groundwater, which ranged between 205 and 3310 mg/L, around 56% of...

Proper and efficient management of coastal groundwater resources is very essential and is an integral part of coastal zone management. The coastal groundwater resources are threatened due to overexploitation. Researchers are curious to understand the location of the boundary between freshwater and seawater in the aquifers. This chapter explains the...

Abstraction of groundwater resources is increasing over the years to meet its ever increasing demand for industrial, agricultural and domestic purposes throughout the world. The scenario is even worse in the east flowing rivers of the Western Ghats, where the demand of water is high under changing climatic conditions. Such situation may affect the...

Multi layered coastal aquifers are complex aquifer system since the interaction between aquifers plays a major role in controlling the chemistry of groundwater. The objective is to understand the interaction between multi aquifers in an urbanised coastal region of Sankaraparani river basin, India using geochemical indicators. Hydrogeologically, the...

Monitoring of groundwater quality is essential in rural regions of developing nations, as most of the population depends on groundwater for various purposes. This study was carried out with the objective of assessing the groundwater quality to evaluate the suitability of water for drinking and irrigational purposes in northern Karnataka, India. Gro...