eChapters

Abstract

A study on the Subsurface groundwater discharge (SGD) in the coastal Cuddalore region of south east India has been carried out. Measurement of surface water Radon, Water level, Electrical Conductivity (EC) and pH for a total of twenty four hours, by hourly interval the measurement has been calculated and promote correlated with tidal values calculated by WX Tide 32 software. The SGD measurements were made by using a modified seepage meter. The study reveals a match with water level variation and tide with minor variation due to influx of surface water. Saline discharges, fresh groundwater discharges and surface water mixing processes were identified along the coast. Lower SGD (37.24 – 79.16 cm/day) were observed during fresh groundwater discharge.

Abstract

Aquifers are usually composed of permeable layers that can ways a considerable amount of groundwater. Usually, aquifer units are correlated through the concept of lithostratigraphy. For low-permeable aquifers, it is difficult to define the spatial distribution of hydrogeological units, and this study attempts to use geochemical methods to identify the groundwater flow paths in an area of Southeast coast of Tamil Nadu, India. Multiple geochemical analyses, including groundwater chemistry; stable isotopic compositions of d¹⁸O and 8D contents were performed.  Spatial distribution of d¹⁸O, dD, Cl-/HCO-₃ show that northeastern part of the study area seriously affected by seawater intrusion. The highly permeable aquifers at the east coastal region are characterized by high hydraulic conductivity as compared with other regions of the study area. Hydrogeochemical characteristics based on bivariate diagrams of major and minor ions show that changes in the chemical composition of groundwater are mainly controlled by the salinization process followed by cation-exchange reactions.

Abstract

Coastal aquifers are the sources of freshwater which are being over extracted due to increase in population, agriculture and industrial activities. This over exploitation has resulted in decline in groundwater level and intrusion of sea water into the coastal aquifers making it unfit for human utilities. An attempt has been made in the coastal tracts of Pondicherry region using Electrical resistivity imaging. The survey has been attempted in six locations spread thought the study area and the interpretation has been attempted by RES2DINV software. The profile length attempted was between 150 to 300 m with electrode spacings between 5 to 10 m. The apparent resistivity ranges between 0.1 to 1183 & ohm. Sea water intrusion was prominent along the northern parts of the study area and lower resistivity isolated in kirumambakkam has been interpreted as salinity due to the presence of clay minerals. In nallavadu saline intrusion has been identified at shallow depth.

Abstract

Deduction of overindulgence fluoride (F)  from the water has been endeavor by numerous investigators by using different materials both natural and artificial. The objective of this paper was to attempt the fluoride removal by using the locally available natural materials such as red soil, untreated charcoal, local powdered brick, fly-ash from Neyveli (thermal power plant) and mineral serpentine were used, adopting column method. Maximum defluoridation occurs immediately after the experiment has started. The morality of fluoride removed per gram is more in red soil when compared to the other materials. Variation of fluoride removal with time was studied after the erection of the column /unit, the defluoridation setup was then connected to the public water supply from the overhead tank of 50,000L capacity. Higher F removal was noted when flow rate was lesser. An attempt on the regeneration of the fluoride adsorbed soil was also made.

Abstract

A total of 30 groundwater samples were collected in four different seasons (Pre Monsoon, South West Monsoon, North East Monsoon and Post Monsoon) from the coastal aquifers of Kalpakkam region of Tamilnadu. The samples were collected covering the seasonal and lithological variations to infer the influence of natural geochemical processes and anthropogenic sources on the groundwater chemistry. The collected samples were analysed for the parameters like EC, pH and Major ions. The saturation index of silicates and carbonates shows that state of saturation to over saturation, but the sulphate minerals is dominantly under saturated. In the inverse modeling three models are obtained using PHREEQC and the error percentage is noted as 7.45%.

Abstract

The geochemical signature and vulnerability of groundwater of the East Coastal aquifers of  India from Pondicherry to Nagapattinam were determined. The coastal aquifers are fragile and this situation becomes more intense in aquifer systems like that of the Pondicherry to Nagapattinam region. A total of 136 water samples were collected during pre and post monsoon of 2008 and 2009 respectively. Out of which 45 samples for each pre and post monsoon from shallow groundwater and 23 samples for each pre and post monsoon from deeper groundwater.. The samples collected were analysed for major, minor cations and anions. Selected samples were also analysed for stable isotopes (d¹⁸O and dD). The analysed samples were studied for; their utility for different purpose, the nature of the geochemical classification, their variations in ion ratios, extent of sea water intrusion and the percentage of mixing, The study reveals that chief mechanism controlling shallow groundwater is the salts precipitated in the pore spaces during the Pre monsoon were leached and dissolved during the subsequent monsoon apart from sea water intrusion. Southern part of the study area  is more vulnerable than the Northern part of the study area.

Abstract

In semiarid climates, a significant component of recharge to basin aquifers occurs along the mountain front. In this scenario Mountain Front Recharge study has been carried along the foothills of Courtallam ,Tamil Nadu. A total of 53 groundwater samples were collected along the foothills and measured for major cations and anions using standard procedure. Saturation index (SI) of carbonate minerals like Aragonite,Magnesite, Calcite and Dolomite,LogpCO₂ and Ionic strength obtained from WATEQ4F output. pH plays a significant role in the saturation index of the minerals. Most of the Carbonate minerals shows undersaturation  with the pH range 7.5. Positive relationship between SI and HCO₃ is noticed. A sharp increase of pCO₂ values towards the foothills region suggests that the groundwater has been recharged by, acquiring longer flow path during its infiltration into deeper level near foot hill region. The SI of these carbonate minerals was spatially distributed to identify the areas of higher SI and also it is compared with the water level fluctuation to understand the recharge process along the foothill region as well as riparian zone.

Abstract

Quality of water is affected by natural and man induced contamination to groundwater system. Area chosen for study has gained its own importance due to the location of two lignite mines and a Thermal power plant in operation. Extensive large scale pumping of water is done for lignite mining. The mine drainage and drainage from thermal power plant along with agricultural return flow from lignite charged waters increases the severity of problem. In order to achieve a panacea for the above-mentioned situation, the study has incorporated and integrated in all related factors to get a meaningful interpretation for groundwater quality and quantity management in and around Neyveli area. The frequent failure of monsoon has added to the existing problem of over exploitation. To attain a panacea for water chemistry groundwater samples were collected for four different seasons. Higher EC and TDS values are observed in Southeast and Southwest part of the study area. In Southwest monsoon and Summer seasons HCO₃Cl dominates the anions, with few representations for SO₄. In Northeast monsoon and Post monsoon season Na + K – Ca + Mg is the dominant. Thermodynamic, studies reveal that groundwater of the region are stable with Kaolinite stability field in all the silicate systems. Bicarbonates derived from silicate mineral weathering are noted in the NW, Northern and in the mining region. These regions are located in the NW and NE part of the study area. Comparison of water quality to standards shows that the water can be used for drinking and for irrigation purposes except in few locations.

Abstract

Radon being the radioactive daughter product of Uranium; the interrelationship between U and Rn has been established in the present study. It is found that Radon coexist with Uranium in the region. A total of 61 samples were collected spatially from hand pumps and bore wells of the study area. Major ions such as Ca²⁺, Mg²⁺, Na⁺, K⁺, F^-, Cl^-, HCO^3-, NO^3-, H₄SiO₄,PO₄- and SO₄^2- and U, Rn were analysed. The lithological influence of U and Radon occurrence is also highlighted. Hard rocks especially Granites are the source for both U and Rn in the study area whereas the lack of correlation exist between U and Rn in sedimentary terrain can be attributed to difference in flow conditions and chemical properties of these elements. 

Key words: Radon, Uranium, Granite, Ground water, Source.
 

Common name    :    English- Common Cocklebur
        Hindi- Chhota dhatura/Ghagra
        Odia- Mendhaguli

Family    :    Asteraceae

Habit & Distribution
The plant is a herb (Fig. 90 a), found in cultivated lands, coastal dunes, water resources, roadsides, waste places and field edges. It is distributed throughout India.

General Characters
The plant has large and broad leaves, light and bright green in colour in an alternate pattern with irregular lobes. Stem turns maroon to black when mature, with hairy appearance. The flowers are white or green, numerous and covered with hooked bristles. The fruit is obovoid, 1.5-2.5 cm long and covered with hooked spines of 2-4 mm long. The plant flowers and bears fruits during August-September.

Common name    :    English- Rangoon creeper
        Hindi- Madhumalti
        Odia- Madhumalati

Family    :    Combretaceae
 
Habit & Distribution
It is a climbing shrub (Fig. 89 a), cultivated widely in gardens and distributed throughout India.

General Characters
The plant is a twining climber blooming profusely throughout summer and can reach up to 70 feet in tropical climate. The leaves are elliptic-oblong and 7-15 cm long. Flowers are scented, pink-white to reddish-white in colour and grow in pendent racemes with a very fast rate. The plant flowers and bears fruits in most parts of the year.

Common name    :    English- Burr Bush
        Hindi- Chikti
        Odia- Badya chana pata/tatatatia

Family    :    Tiliaceae

Habit & Distribution
The plant is a herb (Fig. 88 a), fairly common weed, distributed throughout tropical and subtropical India.

General Characters
It is an erect woody herb, grows up to 30-90 cm. leaves are simple, alternate, broadly ovate to sub orbicular. Flowers are yellow, small and clustered on leaf axils. Fruit is a subglobose and about 3-4 mm in diameter, covered with 75-100 hooked spines of 1.0 to 1.5 mm long. The plant flowers and bears fruits during July-January.

Common name    :    English- Coat buttons
        Hindi- Khal-Muriya
        Odia- Bisalya karani

Family    :    Asteraceae
 
Habit & Distribution
The plant is a herb (Fig. 87 a), usually found in dry locations, especially sandy and rocky sites like roadsides, railways, dunes and waste places. It is widely distributed throughout India.
 
General Characters
The plant is a perennial herb that stands about 30-60 cm in height and has slightly hairy stem. The leaves are ovate or lanceolate with toothed edges. Flowers are small, creamy or white in colour having 5 petals that are notched in the outer edges. The centre of the flower is yellow. The plant flowers and bears fruits all the year round.

Common name    :    English- False white teak
        Hindi- Pindar
        Odia- Jandakhai

Family    :    Euphorbiaceae
 
Habit & Distribution 
The plant is a tree (Fig. 86 a), commonly found along riverbanks, evergreen and semi-evergreen forests. It is distributed throughout India.

General Characters
It is a large deciduous tree, growing up to 10-20 m tall, with a smooth grey bark. The leaves are oppositely arranged ovate, 7-17 cm long and are heart- shaped at the base and have tapering tips. Leaf-stalks are 3-7 cm long. Flowers are small and greenish. Male flowers are borne in 7-19 cm long racemes and are carried on slender stalks. Female flowers are borne singly on long stalks. Fruit is round, with 2-4 compartments, 2-4 cm in diameter, smooth or hairy, exocarp thick and fleshy. The plant flowers and bears fruits during December-March.

Common name    :    English- Indian Tinospora
        Hindi- Gulbel
        Odia- Gulochi

Family    :    Menispermaceae
 
Habit & Distribution
It is a shrub/climber (Fig. 85 a), frequently found in forests and widely distributed throught tropical India.

General Characters
The plant is a climber, with stems about 5 cm diameters with light grey and papery bark. The leaves are about 7.5-14 cm long, broadly ovate or orbicular, deeply heart shaped at the base. Flowers are racemes which are 7-14 cm in long, greenish yellow in colour and arranged in 3+3 sepals in 2 layers, the outer one are small, the inner one are large. Fruits are red, globose to subglobose with 6-8 mm across. The plant flowers during August-December and bears fruits during March-May.

Common name    :    English- Teak
        Hindi- Sagun
        Odia- Sagwan 

Family    :    Verbenaceae

Habit & Distribution 
The plant is a tree (Fig. 84 a), naturally confined to south-western part of Orissa, also widely planted all over the state. The plant commonly distributed in central India to Orissa, also widely planted.

General Characters
It is a large deciduous and very popular timber tree. Leaves of the tree are large, opposite with 30-60 cm long and 15-30 cm broad. The flowers appear in large numbers in lax clusters at the end of branches with white colour. The fruit is about 15 mm across, spongy and enclosed in persistent calyx. The plant flowers during July-August and bears fruit during December-April. 

Common name    :    English- Tamarind
        Hindi- Imli 
        Odia- Tentuli

Family    :    Fabaceae

Habit & Distribution 
The plant is a large tree (Fig. 83 a), fairly common, planted or self sown. It is widely distributed throughout India, also cultivated and self-sown.

General Characters
It is a large tree which grows up to 30-50 m height with spreading crown up to 12 m in diameter. The leaves are up to 5 cm long and composed of numerous small leaflets. Leaflets are 10-20 pairs, small and close. The flowers are about 1 cm across, pale yellow with purple or red veins. Fruits are brown, short haired, sausage like, contain an acidic pulp that surrounds the seeds, extremely sour. The plant flowers during April-June and bears fruits during December-March.

Common name    :    English- Marigold
        Hindi- Genda 
        Odia- Gendu

Family    :    Asteraceae

Habit & Distribution
It is a herb (Fig. 82 a) commonly cultivated in gardens. It is a very popular flowering plant commonly found in India and other countries.

General Characters
The plant is a very popular aromatic annual herb with 50-100 cm in height. The leaves are pinnately divided, in to oblong or lanceolate. Flowers are yellow, orange in colour, and large head with 3-5 inches across. The plant flowers mainly during cold season.

Common name    :    English- Tropical soda apple
        Odia- Denga bheji/Bheji baigana

Family    :    Solanaceae

Habit & Distribution
It is a perennial shrub (Fig. 81 a), is commonly found in grassland, thickets and disturbed places such as roadsides and river banks.

General Characters
The plant is an erect perennial shrub, reaches up to 50-150 cm high with shortly pubescent stems and branches with recurved prickles up to 5 mm long. The leaves are broadly ovate up to 20 cm long and 15 cm wide, generally dark green in colour, and glossy above. The flowers are white, 1.5 cm across arranged in clusters. The fruit is a globose berry, mottled green when young and yellow at maturity, with 2-3 cm across. The plant flowers and bears fruits throughout the year.

Common name    :    English- Sugarcane
        Hindi- Ganna
        Odia- Akho

Family    :    Poaceae

Habit & Distribution 
It is a tall herb (Fig. 80 a), widely cultivated in Odisha and also throughout the hotter parts of India.

General Characters
The plant is a giant grass. The stem is erect, jointed, 3-5 m tall, 2-3 cm thick with plenty of juice. Leaves are elongate, rigid, mostly 4-6 cm wide, with a very thick midrib. The flowers are white, appear in plume like panicles, 20-60 cm long. The plant flowers and bears fruits during November-January.