eChapters

ABSTRACT

Mineral exploration is not only highly imaginative and creative but a very costly activity as well. The fast emerging Geomatics technology is a real boon in mineral exploration as it encompasses a whole spectrum of solutions and services which are of great help for exploration geologists. Geological maps which generally form the basic requirement for any kind of natural resources inventory operations currently witness tremendous changes and the same is mainly attributed to the integration of Geomatics technology. Usage of Geomatics has revolutionized the art of mineral exploration as geological maps can be easily integrated with other important details like geomorphology, structure and tectonic pattern, geophysical data etc. This kind of data integration facilitates for the better identification of mineralized zones. In addition, GIS with its powerful analyzing capability provides tools at several stages in the process of mapping for building up a database containing various types of data for quantifying and extracting features related to mineralization. The present paper narrates an overview of mineral exploration using Geomatics technology.

ABSTRACT

We report here the occurrence of chrysoberyl bearing gem pegmatitesof Southern India. The Pan-African Chrysoberyl mineralization is associated with intrusive event of grey pegmatites within granulite facies parametamorphic aluminous khondalites. Lithological and structural controls of chrysoberyl mineralization are discussed. The chrysoberyl occurrences in southern India, southern Madagascar and Sri Lanka provide strong evidence for India-Sri Lanka-Madagascar juxtaposition in the East Gondwana assembly with the Achankovil Shear Zone of Southern India one side extending into Ranotsara Shear Zone in Southern Madagascar and other side into southern tip of Sri Lanka.

ABSTRACT

Sedimentological studies such as textural, heavy mineral and clay mineralogy have been carried out for Warkalli Formations at Varkala, situated in the southern part of Kerala, India. The X-ray diffraction study reveals that kaolinite is the only clay mineral present in all the samples with trace amounts of gibbsite and goethite. The higher amount of kaolinite and gibbsite indicates warm and humid paleoclimatic conditions. The textural analysis shows that the sediments are moderate to poorly sorted, nearly symmetrical to fine skewed and lepto to mesokurtic in nature. A plot of skewness against sorting shows fluvial trend. The major heavy minerals present in the samples are magnetite, ilmenite, rutile, sillimanite, anatase and zircon. It can be inferred from these studies that these sediments would have been deposited in a lagoon by fluvial action. During that time, the source region has experienced tropical humid climate with mean annual precipitation (MAP) above 200 cm and intensive chemical weathering. Heavy mineral assemblage indicates medium to high grade metamorphic source rocks.

ABSTRACT

The Cretaceous formation of Ariyalur area is well known for its lithological and faunal variation. It contains rich assemblages of fossils as well as the occurrence of economic deposits of limestone, gypsum, phosphatic nodules and clays. Representative Uttatur clay samples have been collected and analysed for physical and chemical properties. The physical properties such as fired colour, plasticity, fusing temperature, slaging nature, shrinkage test, bulk density, liquid limit, and plastic limit and Atterberg number etc. of uttatur clays have been determined. The chemical properties of the clays show low in silica and alumina and high iron and lime which make them suitable for low duty refractories and stoneware works.

ABSTRACT

54 foraminiferal species belonging to 29 genera, 23 families, 17 superfamilies and 5 suborders have been identified from Nagaland. Of the total species 16 are planktic and 38 are benthic forms. The age for the Upper Disang Group of Nagaland is assigned as Late Eocene, based on the presence of Late Eocene markers i.e. Globigerinatheka semiinvoluta, Cribrohantkenina inflata, Hantkenina alabamensis and Turborotalia cerroazulensis. As per the present study the Disang succession in Nagaland can be grouped into five biofacies. The Uvigerina dominated biofacies consisting Uvigerina cocoaensis, U. continuosa, U. eocaena, U. glabrans, U. jacksonensis and U. cf. steyeri. In some samples even up to 100 % Uvigerina were present. The localized occurrence of thick “Uvigerinids” in high percentage with pyritized test in this section indicates anoxic conditions, suggestive of possible source rock for oil.

ABSTRACT

Using a hand auger of 2 m length, upper, middle and lower core sediment samples of seventy nine in number have been collected from the Vaippar river, its tributaries and Vaippar beach in order to understand the role of Vaippar river and its tributaries in making up the Vaippar beach placer deposits. The heavies are found to be concentrated abundantly in fine and very fine size grades of all the samples collected from both the environments. The average heavy mineral concentration varies from 3.13 to 17.40 % in river bed while it is 6.19 – 64.82 % in the beach. In river bed, the pattern of concentration of heavies in upper, middle and lower core samples does not show any characteristic uniform pattern and inferred that it is controlled by the grain size of the parent rock, supply of sediments from the source, geomorphological features of the river and hydrological characters of running water. In the beach, the concentration of heavies are effected mainly due to the winnowing action of waves. However, a phenomenal increase in the heavy mineral concentration of beach samples might be due to the supply of sediments from other source besides the Vaippar river.

ABSTRACT

Lineaments are the surficial expression of sub-surface phenomena which are well discerned from low-orbital data, satellite data with its synoptic view and repetitive coverage and help to bring out more information on structural features hither to unknown by conventional geological surveys. Their study paved way to many new concepts on tectonism, mineralization, structural deformity etc. of an area both in regional and local perspective. In the present study, a small area was selected after careful observation, for their importance in mineral deposits. The lineaments are mostly structurally controlled and analysed for their relationship with the base metal deposits of the area. Moreover satellite parameters like spatial resolution, scale etc., and are observed for their changes in their orientation and relationship with the deposit of the study area, Jambughoda of Panchmahal District, Gujarat Satellite data of Landsat MSS and TM are used for the analysis. The results proved that the satellite parameters are important criteria and play a vital role in lineament analysis for mineral investigation.

ABSTRACT

Coastal zones are credited for the important role they play in the economic, industrial and commercial activities of many countries. Starting from the early fifties of the last century, coastal zones have attracted greater attention from the earth scientists owing to the discovery of huge hydrocarbon deposits in the Persian Gulf, Africa and South America. In addition, coastal zones especially those bordering Precambrian Cratons house significant quantities of economically important placer minerals which are being explored and exploited vigorously. In the present paper, sedimentary basins located along the continental margins of Tamil Nadu state, their geology and hydrocarbon potential are discussed. In addition, an attempt has also been made to demonstrate the usefulness of remote sensing techniques in the exploration of this strategic mineral.

ABSTRACT

Mapping and exploration of iron ore deposits in parts of Salem District is carried out based on the detailed field work and the interpretations of IRS-1C PAN data in the scale of 1:12,500 and aerial photographs (NRSA, Scale 1:4,000). The study results that the major rock types of the study area are banded magnetite quartzite, garnetiferous pyroxene granulite, amphibolite, garnetiferous pyroxenite, charnokite, talc tremolite, actionalite and dunite rocks. The Banded Magnetite Quartzite’s (BMQ) occur as enclaves within the hornblende gneisses at several parts of the study area. Topographically, the rocks constitute small low-lying linear ridges at some places it is found to be closely associated with garnet pyroxene granulites. A remarkable feature about the mode of occurrence of magnetite quartzite is its linear nature and the physical form, which could be described as a “Band”. All the bands possess an ENE-WSW strike and the dip is found to be steep (above 70 degrees) towards north. The rock in the hills of Godumalai, Vellalagundam, and Singipuram are highly deformed and contact with garnetiferous pyroxene granulite and hornblende gneisses. In hand specimen, the magnetite quartzite rock exhibits fine banding. In general no variation in grain size or thickness of banding could be seen megascopically. However, occasional increase in size of magnetite might be possible as seen from the coarser magnetite pebbles strewn in the channels of the area. There are two types of folds observed namely F1 and F2. The axial plane trace of the F1 varies in trend from WNW-ESE to WSW – ENE. The joints are traced in the directions of NNW-SSE to NNE – SSW and WNW – ESE to ENE-WSW. The interpretation of lineaments shows their trend directions of NNE-SSW, NE-SWand NNW-SSE. The above said work has carried out through detailed field work and interpretations using by IRS-1C PAN data in the scale of 1:12,500 and aerial photographs of NRSA, in the scale of 1:4,000 for the study area.

ABSTRACT

In Tamilnadu majority of the people are engaged in agricultural work and they mainly depend upon the water resources. But at present both surface and subsurface water has become deficient because of over exploitation. Since last few years, conventional methods were employed to improve the surface and subsurface water conditions. But these methods provide less accurate result and consume more time. So to improve the conditions modern tools, such as remote sensing and GIS are being used to identify the ground water potential zones in Tamilnadu. It provides accurate resulst and consumes less time.

A project was carried out in Gadilam lower sub basin which falls in the part of Cuddalore District, Tamilnadu. The IRS 1D imagery was collected and interpreted using image processing software and Geo media GIS Software in conjunction with collateral data to prepare Hydro geomorphology, land use, geology and lineament maps Field checks were made and transferred the field data on the base map. By application of overlay analysis of the above thematic maps, using GIS techniques, the recharge zones were identified.

The satellite image mosaic map of Gadilam lower sub basin was generated to identify ground water potential zones. Average monthly rainfall data for the past 50 years were collected. Using Remote sensing and GIS techniques, the thematic maps such as Geology, Geomorphology, Soil, Drainage, Land use, Lineament zones have been generated for this study. Geophysical survey was also conducted in various locations and the aquifer parameters were measured. Details related to land and water resources, cropping pattern, water levels and water qualities from PWD ground water division, land use and well censes data of villages from village Administrative Officer, tank details from PWD were collected and analyzed

After analyzing the various thematic maps, they were finally overlaid. Thus the groundwater potential zones of Gadilam lower sub basin was identified.

ABSTRACT

The geological and geomorphological features could be clearly demarcated in and around Salem area using IRS -IB LISS II satellite data. Geologically,the study area is classified into four major rock types fissile hornblende biotite gneiss, banded magnetite quartzites, peninsular gneiss, charnockites and quartzites. The geomorphological study reveals the buried pediments medium, buried pediments deep, bazada zone, along with lineaments. Intersections of the lineaments are the most prospective zones for further groundwater targeting. Shallow pediments and pediments are the less groundwater prospective zones. But detailed geophysical survey as required to sink new bore well, dug well, dug cum bore wells.

ABSTRACT

The present paper discusses about the Geoelectrical response over Charnockite rocks and Biotite Gneiss rock types of Sankaran kovil and Tenkasi Taluks of Tirunelveli District, Tamilnadu. The study area is adjoined to the Western Ghats which geologically comprises Archean crystalline hard rocks. In this attempt, about 7 Vertical Electrical Soundings (3 in Gneiss and 4 in Charnockite) have been carried out in both terrains. The VES values were interpreted with Schlumberger Sounding Dada Processing and Interpretation Program .The resistivity values varied from 68 m to 808 m with the layer thickness of 10m, 20 m and 29m in the biotite gneiss terrain. Similarly, the resistivity values varied from 48 m to 444 m with the layer thickness of 4m, 6m, 9m,18m & 29m in the charnockite terrain. But the depth to massive rock for both the rock types has been observed below 29m. In this study, a difference in resistivity with high resistivity values in gneissic terrain and lower values in charnockite terrain have been observed. The observed resistivity differences are mainly due to the presence of resisting minerals such as biotite and hornblende. Besides, other factors like weathering and water table also influence the resistivity values. Hence, it is summerised that the geoelectric methods are the best methods to understand the subsurface lithostudies.

ABSTRACT

The exponential growth of population and rapid industrialization, urbanization, deforestation and improper landuse practices have led to depletion and pollution of surface and ground water resources in Tamilnadu, India. In addition, a recurrent monsoonal failure further aggravates the problem of water even for drinking water. Water plays vital role in our day to day life and other developmental activities in the area. Thus, the availability of surface and sub surface water potential governs the processes of planning and development. The surface water resources are inadequate to fill the water demand and productivity through ground water is quite high as compared to surface water. Keeping this in view, the present study is aimed to identify the potential location of potable groundwater exploration in hard rock terrain. Thematic information on geomorphic landforms, Landuse/landcover and lineament details are extracted from remotely sensed data. Geology, Soil class, Drainage network and Slope map of the terrain were prepared using existing maps and collateral data by conventional method. GIS based model was developed and appropriate rank and weightage had been assigned to all categories based on local conditions/variations in each layer according to relative contribution towards the desired output. Since the present study built with logical condition and reasoning rule based approach for groundwater targeting, it has been successfully used and clearly demonstrated the capability of Remote Sensing and GIS techniques in identification of potable ground water potential zones.

ABSTRACT

Assessment of groundwater potential has wide importance in the exploration, management and development of groundwater resource. The fact that geologic and topographic factors, such as, geomorphology, lithology, structure, soil and slope control the occurrence and movement of groundwater in a region has been made use of in satellite remote sensing to aid groundwater exploration. In hard rock terrains, due to lack of primary porosity, lineaments have greater importance as those can be zones of secondary porosity trapping groundwater in its pore spaces.

In the present study, an attempt has been made to delineate groundwater potential zones in the hard rock terrain in the Gayatri River basin in Kerala, India, using satellite data. The study area which lies between 10o 26’N and 10o 45’N latitudes and 76o 21’E and 76o 54’E longitudes covering an area of about 1000 square kilometers is a drought-prone area. Landsat 7 ETM image of Gayatri River basin has been interpreted visually in a digital environment using ERDAS Imagine software to create geomorphology and lineament maps. Further, with the help of ancillary data, various thematic layers like, lithology, soil, drainage density, etc. have been created and subsequently updated using information obtained from the satellite data. Slope map of the basin has been created using Shuttle Radar Topographic Mission (SRTM) data. Integration of the thematic layers has been done in Arc/Info GRID GIS environment by giving weights to various thematic layers according to their importance in terms of groundwater occurrence. Finally, groundwater potential map of the basin has been prepared by classifying groundwater potential zones as good, moderate and poor.

ABSTRACT

The upper Agniar and Vellar river basins principally consist of three major rock typesnamely pink granite, gneiss and charnockite. The major geochemical pattern of these igneous rocks when studied indicate that charnockites have a trend of low Mg2+ and high Ca2+ + Na O to high K+ end, whereas the same is vice – versa for hornblende biotite gneiss and also for granite gneiss. The pink granite has an intermediate trend between the charnockite and hornblende biotite gneiss. The value of SiO2 in all the rock types was found to increase with the increase of K2O, Na2O and Al2O3. Further, a decrease in the values of MgO, Fe2O3, TiO2 and CaO was noticed with an increase in SiO2. On the basis of the distribution pattern of these elements, the origin of the igneous suites in the above two basins was inferred.

ABSTRACT

Due to complex hydrogeological conditions it becomes very difficult to prospect the ground water resources especially in drought prone areas where the water table is very deep. The interpretation of geoelectrical sounding curves also becomes ambiguous. A semi empirical method namely theinverse slope method [Shankar Narayan and Ramanujachari, NGRI] is widely used since it is simple to operate without standard curves etc and it gives fairly good results. In some Government organizations like PWD [Ground Water Department] and TWAD Board of Tamilnadu, this inverse slope method is widely used for ground water exploration. Based on this methodology, ample of bore well points have been recommended in complicated hard rock terrains and the success rate is found to be encouraging. The study area, Kavalpatti, of Palani taluk in Dindigul district is a crystalline rock terrain, where geological, hydrogeological and geoelectrical investigations have been carried out to explore the ground water potential zone for agricultural purpose. The bore well drilled to a depth of 32 m has yielded 370 lpm. The interpreted geoelectrical section has been correlated with the litholog of bore well. Some bore well statistics [bore well points recommended based on this method] has been furnished, which reveals that this methodology is encouraging.

ABSTRACT

Over the past four decades groundwater has become a topic of discussion and investigation and as a result the knowledge of understanding groundwater conditions has radically improved. For the past quarter century, remote sensing has played a vital role to target the groundwater resources for the essential survival of horticulture and agriculture crops in drought-prone areas. GIS technology has made a rapid stride for the past one decade to amalgamate the data generated from various space-born platforms and the ground based surveys to facilitate the generation and use of various thematic information for groundwater resources assessment. The present study aims for the demarcation of various groundwater prospective zones in the West Doon Valley and its environs, falling in the SOI toposheet 53 F/15. The role of various parameters namely, Geomorphology, Geology, Lineaments, Drainage, Land Use, Water table and Slope has been integrated for delineating groundwater prospective zones. IRS IC LISS-III geocoded satellite image on 1:50,000 scale was used. Index overlay model has been applied for GIS analysis. The resultant map indicates five prospective zones, such as poor, low, moderate, high and very high groundwater prospective zones in the study area.

ABSTRACT

Airborne geophysical methods are presently used all over the world to support mineral exploration by providing basic geological information to supplement existing geological maps. The popularity of airborne geophysics is due to its lower cost for unit of area surveyed, as compared to all other methods of exploration. South India has been extensively covered by high altitude regional aeromagnetic surveys jointly by GSI and NRSA, low altitude multi-sensor surveys by foreign agencies, viz. M/s. Parsons, U.S.A. (Operation Hard rock Project) and BRGM/CGG, France, on contractual basis for GSI and by GSI (Twin Otter surveys) in selected belts and low altitude aeromagnetic surveys by NGRI in the SW part of the Cuddapah basin and the adjoining crystallines. Integrated studies of geophysical (airborne and ground), geological and remote sensing data have greatly helped not only in augmenting the geological knowledge of the region, but also in identifying several metallic prospects/ deposits. The present paper illustrates several case studies in demonstrating the utility of aerogeophysical data in geological mapping (identifying lithologies, structures and basement characteristics) and locating metallic prospects/ deposits.

ABSTRACT

With the increasing use of ground water for various activities, the fast decline in groundwater takes place. In order to prevent the aquifers from fast depletion, the ground water recharge is necessary. This study attempts to identify the favourable areas for groundwater recharge and suggest suitable recharge structures toaugment the aquifer system of the study area using Remote Sensing and GIS. The various thematic maps such as Geomorphology, Geology and lineaments, Soil, Slope, Land use, Drainage, Runoff, Depth to weathered zone, Groundwater level fluctuation and Water quality are used in the analysis. The favourable areas for groundwater recharge have been categorized into highly favourable, moderately favourable, less favourable and poor. To delineate areas favourable for recharge zone various themes are interpreted. The identification of ground water recharge zones for the study area is useful for improvement of water quality, quantity and better augmentation & management of Groundwater recharge.

ABSTRACT

The disposal of industrial effluents in rivers causes groundwater contamination. It is necessary to assess how these contaminants are likely to migrate in the groundwater system. In the present study, an attempt is made to study the migration of contaminants in the groundwater of Palar River basin in Tamil Nadu. Simulation of the contaminants was carried out by using numerical methods. The finite difference computer code MODFLOW (Modular 3-d finite difference flow) and MT3D (Mass transport 3-d) with Groundwater Modelling System (GMS) as pre and post processor was used to simulate the groundwater flow and transport in this study. The simulation was done in transient state for a time period of one year. It predicted the migration of plume of chlorides in groundwater. The changes in the distance and concentration rate of chlorides are identified for a particular period. Modelling provides a useful basis for contaminant transport studies, as well as in the evaluation of the hydrogeologic parameters relevant in the context of the transport problem.

ABSTRACT

Kadayampatty Panchayat Union is situated in the northern part of Salem district, adjoining the Dharmapuri district of Tamil nadu. It lies between the latitudes 11°45’ -12°N and longitudes 78° -78°15’E in the Toposheet No.58I/1. The study area mainly consists of the rocks of late Precambrian age that are characterised by migmatitic gneisses, Ultramafic rocks and Pyroxenite. In this study an attempt has been made for demarcating groundwater techniques. Resistivity of rock formation varies over a wide range, depending on the material density, porosity, pore size and shape, water content, quality and temperature. In relatively porous, highly jointed and fractured formation the resistivity is controlled more by water content and quality with in the formation then by the rock resistivity. For demarcating groundwater potential zones in the Kadayampatty Panchayat Union water table analysis and ten Vertical Electrical Sounding (VES) followed by Schlumberger electrode configuration were carried out. The maximum depth of investigation was 150mts. The electrode spreads were generally in steps of five meters interval up to 50 mts and 10 mts interval up to 150 mts. VES location were selected with in the study area with respect to their topographic features. Inverslope method proposed by Sankaranarayan (1974) et.al has been used to evaluate the geoelectrical parameters in order to demarcate to potential groundwater zones for new dug well and bore well locations. The lithological interpretation reveals that the presence of a maximum of five geoelectrical formations in the study area viz. Topsoil, weathered zone, fissure and fractured zone, fracture basement and fresh basement. Howevers all five formations do not occur throughout the study area, as the maximum and minimum of geoelectric layers are four and three respectively. Similarly a thin geoelectric layer was observed in some places also. The comparatively high resistivity values with corresponding high values of thickness are indicative of a wide stretch of unweathered and unfractured fresh rock layers. A highly weathered (saturated) basement is indicated by the extremely low resistivity value. The depth to the fresh basement varies.

ABSTRACT

Identification and mapping of fractures/lineaments and hydrogeomorphic units is prerequisite for undertaking ground water exploration and development in any terrain. Remote sensing and GIS techniques have been used for ground water potential mapping in Theni District. The study area has been divided into various geomorphic units based on visual interpretation of LISS III and PAN merged data in false colour composite on 1:50,000 scale. Ground water potential of each of the geomorphic units was assessed and correlated with geology, structure and recharge factors prevailing in the Theni District.

ABSTRACT

Trace Elements were analysed from water samples collected from bore wells from block 2, 5, 14, 26 and 29 at Neyveli Township. Lead Concentration has crossed the limit of ISI standard prescribed for drinking which is 0.100 ppm. Lead concentration in the order of 0.082 ppm at block 5 and 0.11 ppm in block 29 were observed. Cadmium concentration has also crossed the limit of ISI (0.010 ppm) for drinking purpose, which is 0.02 ppm in block 26. Chromium concentration has also crossed the permissible limit of ISI standards (0.05 ppm) for drinking, which is 0.098 ppm in Block 14.

The above elements when compared with ISI standards for drinking water have shown a slight increase in concentration of lead, cadmium & chromium. Concentration of lead in Neyveli basin may be attributed to basement geochemical sources influenced by physical and chemical weathering. High concentration of chromium and cadmium in the aquifer may be due to anthropogenic activity probably from effluents of closed briqueting & carbonization plant, which is due south of block 14.

ABSTRACT

Mecheri Panchayat union lies in the northwestern part of Salem district and adjascent to Dharmapuri district of Tamil Nadu. It lies between the latitudes 11°43’ -12° and longitudes 77° 48’ -78° 03’ of Toposheet No. 58 E/13 of scale 1:50,000 published by survey of India in 1973. Mecheri Panchayat union covers a total area of about 177.6 Sq.Km with a population nearly 1 lakh, live in 150 hamlets. Groundwater is the only replenshable nature resources available to man. The use of groundwater has been growing steadily over the years for domestic, agricultural and industrial purposes. Hydrogeochemical study is a dynamic process undergoing constant change in space and time. In unconfined aquifers, the change likely to be quite rapid and cyclic in nature with respect to the mode of recharge and discharge and related to the nature of host aquifer. In this study an attempt has been made for understanding the chemical quality of groundwater in theunconfined aquifer of Mecheri union. Groundwater samples have been collected from 10 representative dug wells lying in the Mecheri union during December 2004 and analysed by the standard procedures of water analyses. It is essential in determining its usefulness for domestic, industrial and agricultural purposes. Presentation of Geochemical data in the form of graphical charts such as Collin’s bar, Stiff’s polygon diagram, Pie diagram, Piper tri linear diagram, USSL classification and thematical maps were prepared for recognizing various hydrogeochemical types in the Mecheri union. Deleterious effects of fluoride on the human beings are well known. Fluoride are known to be beneficial, when present in concentration ranging from 0.5 ppm to 1.2 ppm. But when it exceeds the limit 1.2 ppm it is found to cause fluorosis. Dental, skeletal and non-skeletal fluorosis may be caused depending upon the concentration of fluorides in drinking water. The main source of drinking water for the majority of people of Mecheri union is groundwater obtained through dug and bore wells. The analysis of groundwater samples showing high (> 1.5 ppm) fluorite content observed in the following villages, viz Mallikundam, Kuttapatti Aranganur, Banapuram, Sathappadi, Mecheri town, Virudasampatti and Amaram.

ABSTRACT

The study narrates the importance of occurrence of groundwater in the crystalline terrain and its yield in different lithologies. In general, yield of well in the crystalline terrain of the study area is low. Average or mean yields for groups of wells in various regions are most commonly between 7 to 20 gpm: The smallest yields are encountered in granulitic terrain and this may be due to fracture closing rapidly with depth. The jointed and weathered geneses yield small but steady supply of water at shallow depth. Chemical quality of the groundwater from this terrain is generally satisfactory for most purposes.

ABSTRACT

The estimation of the water requirement of crop is one of the basic needs for crop planning on the farm and for the planning of any irrigation project. Water requirements of crops include the losses due to Evapotranspiration (ET) plus the losses during the application of irrigation water (unavailable losses) and the quantity of water required for special operations such as transplanting and leaching of excess salts for crop growth. It is therefore necessary to estimate the ET and Crop Water Requirement (CWR) for the efficient use of water and increased crop production. In the present study, meteorological data were collected and the crop ET (ETc) and the CWR were estimated using FAO Penmann – Monteith method for the cropping pattern of the Buthangudy canal command area situated at a distance of 2Km from the popular village Sethiathope, Cuddalore district, of Tamil Nadu, India, which is located in between the Kumbhakonam – Chennai NH – 45 main road. The methodology combines the capability of GIS and CWR to produce maps showing spatial distribution of water resources over large areas.

ABSTRACT

An integrated geological, hydrogeological and geophysical analyses have been made to delineate groundwater potential zones in the Omalur Panchayat Union, Salem district, Tamilnadu. Sarabanga river is a major stream originating from western slope of Shevaroy hills. The tributaries are essentially consequent types. They are ephemeral in nature and the flow is restricted to the monsoon seasons. The flows of the streams are controlled by lineaments. Low drainage density, stream frequency and low relief indicate relatively high recharges and low runoff. The main lithological units are unclassified gneiss, grantite, charnockite, younger ultramafic rocks and recent alluvium. Ten vertical electrical soundings (VES) were carried out using Schlumberger electrode configuration. The maximum depth of investigation was 150meters when the electrode spread was generally in steps of 5 meters interval up to 50 meters and 10 meter intervals up to 150 meters. The field data were interpreted with the help of inverse slope method. Inverse slope field graphs reveal that in most of the locations, the aquifer consistsof five layers and third and fourth layersare normally weathered and highly fractured layers. These layers have attained a thickness range from 10 to 60 meters at the Tholasampatti, Sikkampatti, Pagalpatti and Sakkaraichettipatti. Correlation between the result of the VES data and the well lithology will be very useful in evolving ground water potential zones. Bore wells, dug wells in this area are normally sinking type wells. It will receive water only from the weathered, fissured and fractured zones which act as a favorable layers zones for tapping groundwater.

ABSTRACT

Ground water is an important source of water supply throughout the world for irrigation, industries, municipalities and rural homes and the dependence of an Indian village is on its water source only. The quality of water is as important as its quality. The quality required of a groundwater supply depends on its purpose such as drinking or agricultural or industries. To establish quality criteria, measures of chemical, physical, biological constituents must be specified as well as standard methods for reporting and comparing results of water analysis .For that a case study is to be made. Cuddalore district is a rapidly growing urbanized industrial area and lies at the east coast of Tamil Nadu in India. It mainly depends on the ground water. Water quality data for the observation wells from the year 1989 to 1999 were collected and spatial distribution of the groundwater quality is analysed using geographic information system. The important factors such as pH, Chloride shows higher level and generally occur in the central belt of the study area which is rich in mineral wealth. Compared to the eastern half the western half shows better quality of water. From the analysis, 80% of the study area is suitable for agricultural purpose and 75% of the study area is suitable for domestic and drinking purpose.

ABSTRACT

The chemical characteristics of the groundwater in and around the Valapadi taluk of Salem district have been studied to evaluate the suitability of water for domestic and irrigation uses. Twenty three groundwater samples representing the shallow and deep aquifer of the area were collected and analyzed for pH, TDS, Ca, Mg, Na, K, HCO3, CO3, SO4 and Cl. It is observed that the quality of the groundwater is suitable for domestic use with some exception. The observed high quantity of Cl, SO4 and Mg at some places require immediate attention and detailed study. The value of EC and SAR indicate good to medium q of water for irrigation.

ABSTRACT

Hydrogeochemistry of a region is a reflection of hydrodynamic process, composition of lithology and physical constraints. The water chemistry is the resultant of all biogeochemical processes and reactions, which have acted on water from the moment it has condensed in atmosphere till the time it is discharged. A case study has been carried out in a varied lithological terrain with Archean, Alluvium and Tertiary rocks to unravel the hydrogeochemical process. A geochemical model relays the distribution of mineral species in the groundwater. Geochemical modeling WATEQ4F has been carried out for pre-monsoon and monsoon period of various litho units in Gadilam river basin, Tamilnadu to find out the disequilibrium indices of carbonate (calcite, dolomite, magnesite and aragonite) and sulfate minerals (anhydrite and gypsum). The result of the model reveals that carbonate minerals show the over saturation state in monsoon period and the Sulfate minerals exhibit under saturation state in both the seasons.

ABSTRACT

Microalgae in general and Cyanobacteria in particular are considered to be ideal biotechnological tools for their importance in the production of food, feed, fuel, fertilizers, fine chemicals and pharmaceuticals and their role in pollution abatement. So far, only 20 strains of microalgae have been cultivated for industrial purposes. To make use of more such organisms, it is essential to first identify their biodiversity in the naturally occurring populations and establish their germplasm for further characterization. With this in view, a detailed survey was made to study the biodiversity of Cyanobacteria in the Veeranam lake soil microflora in the Cuddalore district of Tamil Nadu. Influence of physico-chemical parameters habitat preferences of these soil microalgae, and their light and Electron microscopic features have been documented. The selected species of Cyanophyceae were subjected to energy dispersive spectroscopic analysis (EDS). They were found to accumulate different elements such as Zn, P, Mg, Ca, Mn, S and N. Thus these observations would determine the chemical dialogue between the cell structures and role of the elements. Further, it gives the clue about the soil microflora growth requirements.

ABSTRACT

The sources of fluoride in groundwater are minerals like fluorite, apatite, mica, amphiboles,cryolite and fluor.spar. The undue concentration of fluoride greater than 1 mg/l has befallen a major toxicological and geoenvironmental issue in India. Excess of fluoride in groundwater causes skeletal and dental fluorisis. The study area forms part of Salem district with records of endemic fluorisis. To decipher process and chemistry of fluoride, a total of 46 groundwater samples were collected from major litho units of the study area (Peninsular gneiss and Charnockite) and analyzed for fluoride using standard procedures for two seasons viz. pre and post monsoon. In pre-monsoon, maximum and minimum fluoride in Peninsular gneiss and charnockite were ranging from 2.85 to 0.4 mg/l and 4.02 to 0.37 mg/l respectively. The coresspnding figures in post monsoon ranges from 2.84 to 0.32 mg/l and 1.91to 0.37 mg/l respectively. Higher concentration was noted in charnockite folowed by peninsular gneiss in pre monsoon and the effect of dilution was well noted in post monsoon season. Statistical analysis undercovers the relationship of fluoride minerals with other ions. Modeling results represent the leaching of fluoride minerals and their variation along with seasons.

ABSTRACT

The occurrence of fluoride more than permissible limit has been observed in ground water near Danishpet, Rajammannar Colony, Vayapurikombai, Melkombai, Umbilikampatty, Andikottai HC in Kadyampatty area, Salem district. Fluoride reaches to a maximum of 2.8 mg/l. Fluoride concentrations in ground water in various areas are as follows: Danishpet(2.0mg/l), Rajammannar Colony (2.8mg/l), Vayapurikombai (2.4 mg/l), Melkombai (2.4mg/l), Umbilikampatty (2.2 mg/l), and Andikottai HC (2 mg/l).. Granite gneiss and associated secondary vein filling minerals may be the source of high fluoride in ground water. The high concentration of Fluoride in ground water has led to human health hazard in the form of dental and skeletal deformation in the parts of Danishpet, Rajammar Colony, Vayapurikombai, Melkombai, Umbilikampatti and Andikottai HC villages.

ABSTRACT

A watershed is a topographically delineated area that is drained by a stream system, i.e. the total land area above some point on a stream or river that drains past that point. The watershed is a hydrologic unit that often is used as a physical – biological unit and a social – economic political unit for the planning and management of natural resources. Remote Sensing (RS) and Geographic Information System (GIS) techniques can be used effectively to generate the land use/land cover for evaluating the changes in an area. Conventional methods of runoff measurements are not easy for inaccessible terrain of Tamilnadu. Remote sensing technology can augment the conventional method to a great extent in rainfall-runoff studies. In this study, SCS Curve Number technique modified for Indian condition has been used for generation of CN for an ungauged watershed. A sub watershed of Manimuktha watershed is considered as study area. The daily rainfall data of Virudhachalam rain gauge station is collected and used to predict the daily runoff from the watershed using GIS based Soil Conservation Service -Curve Number (SCS – CN) method (USDA, 1972). Monthly and annual runoff values are obtained from the daily runoff values of the watershed. Base map, Soil map and Land use map of the study area are prepared by using Remote Sensing data and Survey of India (SOI) toposheets. PC Arc/Info GIS software is used for analysis.

ABSTRACT

The use of Geographic information system to locate groundwater possible zone in Valapadi taluk of Salem was carried out using remote sensing and geophysical studies. The remote sensing methods involved in the visual interpretation of the satellite images for hydrogeomorphological and hydro structures favourable for groundwater. The geophysical method involved vertical electrical soundings to predict the sub-surface variation and to locate the water domain. Three geoelectric layers were delineated from the interpretation of vertical electrical sounding data and the map of the above results predict the depth extent of groundwater zone. The spatial distribution of the above results was identified through GIS.

ABSTRACT

The present paper highlights the implication of geochemical strategic tools to choose suitable site selection on the coastal region. Geochemical tools and geomorphological survey have been also deployed to identify the suitable site. The geomorphology of the site A reveals enough fresh water accumulation was found and the two elevated crest and the adjacent trough (low land) with surrounding areas further support the fact. The water quality of this site exposes very good quality (< 200ppm TDS) and the dissolved major anions (HCO3, SO4, Cl) and cations (Ca, Mg, Na, K) concentration are well within drinking water standards. The soil samples are of medium to coarse sand nature showing high porosity (40 to 50%) with mica flakes acting as less permeable in nature. The water quality shows very good in nature and similar to Site A. The soil characters additionally proved good in porosity and permeability (SAR 1.5 to 2.1).

ABSTRACT

The coastal zone is environmentally sensitive and economically valuable, which has great attention from researchers especially from geoscientists. Coastal zone has great threat from pollution and natural calamities like cyclones, flood and tsunami. Natural calamity is a frequent phenomenon over coast. Therefore, it is very essential to monitor the changes over coastal ecosystem and geomorphic features like beach, shoreline and sand dunes. In this case, one of the basic requirements in managing and monitoring these features is the topographic data. The recently emerged technique of Airborne Altimetric LiDAR provides accurate topographic data. It is in preparatory stage in India. By this technique, we can collect the data at high speed when disaster happens. This paper attempts to provide a general overview of the role of LiDAR in coastal management.

ABSTRACT

In order to assess the baseline environmental status in the PTK mines the comprehensive primary data collection / survey programme was undertaken during the period i.e. from April 2003 to June 2003. The environmental monitoring for ambient air quality, water quality, soil quality, noise levels, dust fall, traffic density, meteorology of the study area, etc was carried out. Detailed satellite image interpretation was carried out and thematic maps of the study area were prepared by visual interpretation using tone, texture variations from IRS –IC LISS-III – False Color Composite geo coded images. Digital image processing techniques (supervised classification) were used to classify land use, geology, geomorphology, and drainage pattern/ watersheds and soil cover of the study area. Detailed flora and fauna study was carried out in the study area comprising of core and buffer zones for identification of existing species. The description of baseline environment in the study area is given below.

INTRODUCTION

Remote Sensing is an indigenous tool for the Environmental Impact Assessment study. It plays vital role in preparing various thematic maps for understanding the changes that have taken place in an area before and after the establishment activities. In this study we have utilized the capability of the remote sensing techniques in understanding the mining environment. Our study area is in and around the Dalmiapuram Cement Industry in the central part of Tamil Nadu state and it covers part of Trichy and Perambalur districts. It falls between 11₀ 02’ 42’’and 1₀ 03’ 08’’E and 79₀ 09’ 39’’and 79₀ 10’ 30’’N.Dalmiapuram Cement Industry is located in the Kovandakurichi village of Pullambadi block, Trichy district. The mines for cement manufacturing are Perianagalur (PNR), Periathirukonam (PTK), Kallakudi (KLK), Kovandakurichi (KVK) and A&K Mines.

The litho units are Limestone beds containing various proportions of bioclastic and siliciclastic materials. They show wackstone to rudstone fabric and have clasts of re-deposited bound stones. Deposition in a periodically restricted shallow marine setting was indicated by lithological and faunal information. Lower contact is an unconformity surface associated with marine flooding and the upper contact is non-depositional and erosional with overlying biostormal member.

ABSTRACT

The present work relates to geological and commercial aspects of pyroxene syenite (Green Onyx) occuring in and around Sivamalai of Periyar District in Tamil Nadu. The alkaline complex of Sivamalai comprises syenites-, nepheline syenite and their variants. Pyroxene syenite is possibly the oldest within the syenite complex occurring as minor massifs, elongated linear bodies, -arcuate islands and enclaves within feldspar syenite are observed in the hillocks North East of Sivamalai, namely Chennimalai and its southern extensions. On the commercial point of view, the pyroxene syenite in the study area occupies nearly 30 square -kilometres area and can be categorised as Kalleri Block, Neykkarampalayam Block and Sivamalai Block. The observed petrographic and petrochemical characters of the alkaline rocks of the study area favours magmatic origin for these rocks. A detailed geological study and random market survey of individual syenite bodies proved the true worthiness of the material Green-Onyx as a dimensional stone with substantial resources and market potential.

ABSTRACT

Granite in the present day context is popularly known as the principal raw material in construction industry and also known for its value addition product as Dimension Stone in the global market. India is in pride possession of much sought granite varieties of the world. No doubt the demand for such granite varieties is quite high both for local and export markets but in reality the failure rate of granite quarries is also high, The technical reasons attributed for such failures being lack of application of proper scientific skill both in selection and mining ofgranite deposits. The past experience in the fieldof granite exploitation has thought us a lesson for application of geological knowledge in selection of right deposits and in adopting the right techniques. The selection criteria for construction purpose and for export market though looks simple, is more complicated in the case of dimension stone granite deposits, the reasons being the requirement of thorough knowledge in petrography,structure,geotechnical characters of the deposit. Considering the importance of the scientific knowledge, the present paper focuses on the various parameters for valuation of granite deposits. In other words, it emphasizes on arriving at a logical conclusion by applying the scientific knowledge in successful exploitation of the much valued granite deposits.

The paper deals with the historical perspective of the tsunamis, much widely discussed Kumari Kandam and Lemuria continent and the palaeo-time series changes on the past continents and oceans, disastrous tsunamis since 16^th century and archeological evidences indicating shore line changes along Tamil Nadu coast.

Keywords: Ancient tsunamis in history, Kumari Kandam and Lemuria, Past shore line changes.

INTRODUCTION

A tsunami is a natural phenomenon consisting of a series of waves generated when water in a lake or the sea is rapidly displaced on a massive scale. Earthquakes, landslides, volcanic eruptions and large meteorite impacts all have the potential to generate a tsunami. The effects of a tsunami can range from unnoticeable phenomenon to large scale devastation.

The term “tsunami” is derived from the Japanese language meaning harbour (“tsu”) and wave (“nami”). The term was coined by fishermen who returned to port to find the area surrounding the harbour devastated, although they had not been aware of any wave on the high seas. A tsunami is not a sub-surface event in the deep ocean; it simply has a much smaller amplitude (wave heights) offshore, and a very long wavelength (often hundreds of kilometers long), which is why they generally pass unnoticed at sea, forming only a passing “hump” in the ocean.

Tsunamis were historically referred to as tidal waves because when they approach land they take on the characteristics of a violent onrushing tide rather than the sort of cresting waves that are formed by wind action upon the ocean (with which people are more familiar). However, since they are not actually related to tides the term is considered misleading and its usage is discouraged by oceanographers.

Abstract

There are two distinct types of oscillations in global oceans, separated in their frequencies by the period of the pendulum day. One species is the gravity waves and the other is the rotational waves, associated with earth’s rotation. Both these species can be found in tidal records around islands as well as near coastlines. These two types of modes are usually found in the tsunami records on tide gauges. The tide gauge records as well as visual descriptions of the water levels during and after the occurrence of a tsunami clearly show the presence of these oscillations. During the tsunami of 26th December 2004 in the Indian Ocean, media reports suggested high water levels persisted around the Andaman and Nicobar Islands for several days. These persistent high water levels can be explained by invoking the existence of trapped and partially leaky modes on the shelves surrounding these islands.

Keywords: Oscillations in global waves, Tsunami (2004), Andaman and Nicobar islands.

Abstract

An unprecedented tsunami hit the Andaman and Nicobar Islands and the coasts of Andhra Pradesh, Tamil Nadu, Pondicherry and Kerala on the 26^th of December 2004. The loss of life and property, though wide spread in all these areas, was very severe in thickly populated low lying coasts, such as Nagapattinam in Tamil Nadu. Survey of India, in association with the Department of Science and Technology, Govt. of India, New Delhi has taken-up the task of carrying out post-tsunami Mapping of the entire east coast of Tamil Nadu using Digital aerial stereo images acquired immediately after the tsunami. The project aims to generate ortho-rectified photographs on 1: 8000 scale, which are to be used for preparing damage assessment maps of the affected coastal areas. This paper discusses various issues related to Control Surveying, Digital Photogrammetry and Large Scale feature extraction that are involved in the mapping process in general and its credibility for tsunami damage assessment in particular.

Keywords: Tsunami, Digital Photogrammetry, Tsunami damage assessment in India.

Abstract

The major subduction of the Indian plate and the related high magnitude earthquake (>9M) occurred in Sumatra region, triggered a major tsunami on 26, Dec 2004 which caused massive disasters in many coastal regions of South Asian countries including India, killing tens of thousands of life and causing property loss of several million rupees. Duly realizing the credentials of Geospatial / Geomatics technology and the expertise of NRDMS, an all India coordinated programme was conceived by NRDMS on tsunami disaster assessment and got it executed through six specialized institutions working on geomatics technology in the country. In the programme, the tsunami disaster in terms of natural, physical and human resources were assessed using geomatics technology and village wise digital databases were generated which will form a potential baseline information in coastal area.

Keywords: Indian Ocean Tsunami 2004, DST Initiatives, Disaster Assessment, Mitigation.

Abstract

A very strong shallow focus submarine earthquake (of magnitude 9.0) occurred off the west coast of Sumatra Island due to the movement of Indian Plate and Burma Plate on 26th December 2004 at 06:18:53 IST. A vast area around its epicentre was rocked including Andaman and Nicobar Islands and parts of the eastern and western coasts of the Indian mainland. This earthquake had generated a global tsunami, which had also pounced on the Andaman and Nicobar Islands and the coasts of Andhra Pradesh, Tamil Nadu and Kerala and caused severe damage to the coastal population and infrastructure. Considering the devastation of this tsunamigenic earthquake, the Department of Science & Technology, Govt. of India has launched a coordinated programme for imparting S & T inputs with futuristic approach to support rehabilitation programme in the affected areas on a sustainable manner. The main objective of the programme is to generate geospatial databases on damages and risk zonation using pre and post-tsunami remote sensing (RS) data along with collateral attribute data in GIS platform. This paper speaks on the damage assessment (both natural / physical resources and human resources) caused by the earthquake and tsunami covering parts of Andaman Islands along with strategies for risk management and constraints and alternatives for micro level planning.

Keywords: Tsunamigenic earthquake, Damage Assessment, Remote Sensing and GIS, Andaman - Nicobar.

Abstract

A large tsunami triggered due to a massive earthquake of 9.3M in the offshore of Sumatra on 26^th December 2004 created havoc in several countries of the Indian Ocean. The deadly tsunami waves lashed the towns adjoining the coastline of several countries including Indonesia, Thailand, Malaysia, India and Sri Lanka causing more than 1,50,000 deaths. The earthquake occurred along the plate boundary is marked by a subduction zone between the Indian plate and the Burmese micro plate. In Andhra Pradesh, six coastal Districts were affected and amongst them four south coastal districts experienced maximum damage. In the present study, Tuppalapalem (vagarru revenue village) of Vakadu mandal, Nellore District was selected as a case study for discussion in the article. The objective of the study was to make an inventory of the damages to the natural and physical resources, by preparing pre and post-tsunami maps on geomorphology, land use / land cover, tsunami inundation and finally the tsunami risk zonation map on 1:8,000 scale. In this process, water and soil samples of the affected regions were also collected and chemical analysis was carried out. The data on damages were collected using a specially formulated data sheet. High resolution IKONOS data of January 2000 and IRS data of January 2005 were used for the generation of respectively the pre and post-tsunami geomorphology and land use / land cover maps. Ground truth data were also incorporated in these thematic maps.

The study has revealed that the water in all the bore wells became brackish after tsunami. About 80 country boats, 40 fibre boats and nets were lost with an estimated loss of about one crore. The tidal waters damaged the bunds of the aqua-farms and deposited the transported sediments in them. The extensive casuarina plantations, were reduced by the onslaught of tsunami and the casuarina trees became brown due to their contact with tidal waters. From amongst the various geomorphic units mapped in the study area, the beach, spits, shoals, creeks, swales, palaeo creeks were inundated by tsunami where as beach ridges, dune complexes and stabilized sand dunes were not affected and hence inferred as barriers. Geomorphology, land use / land cover and the tsunami inundation maps, tsunami risk zonation map were prepared showing very high, high and moderate zones of tsunami risks. It is recommended to take up casuarina plantations extensively along the coast as a biowall, which will also provide employment to the local people. The shallow aquifers of the coastal environment were contaminated by the tidal waves. Hence, drinking water should be supplied through protected water supply schemes. As a part of the community development, proper awareness must be created through training and appraisal to the fisherman community to face such natural disasters. The coastal regulation zone act, which prohibits any construction activity within 500m of the high tide line, should be strictly enforced. Keeping in view of the experience, a holistic tsunami protection plan is needed to safe guard the Indian coasts.

Abstract

The recent tsunami occurred on 26^thDecember 2004, caused great devastation along the east coast of Tamil Nadu, India. As the said tsunami has caused colossal damages, the impact assessment has become essential for tsunami mitigation measures. In this context, the extent of tsunami inundation, loss of lives, property loss and damages to physical and natural resources have been assessed in the tsunami affected area between Ennore and Mahabalipuram along the east coast of Tamil Nadu.

IRS LISS III PAN merged satellite data and IKONOS data were used for mapping the pre-tsunami geomorphology and land cover conditions and IRS-P6 PAN merged satellite data were used to map the post – tsunami terrain conditions including the inundations. From the study it is inferred that wherever buildings and population are denser the loss is more. Hence, vertical expansion may be needed as an alternative or to supplement horizontal expansion. Bio-shield along coastal areas, involving raising of mangrove forests, planting of casurina, salicornia, palms, bamboo and other tree species and halophytes which can grow near the sea will serve as speed-breakers for the up rising waves.

Keywords: Tsunami, Damage Assessment, Mitigation Measures, Chennai region.

Abstract

The tsunami has struck many coastal countries of South Asia on 26 December 2004 and caused greater devastation along Andaman - Nicobar and Indian coasts. In India, Tamil Nadu coast is worst affected in Kanyakumari, Nagapattinam and Cuddalore districts. Subsequently, damage assessment, in respect of natural and physical resources, was done using Remote Sensing and GIS in parts of Cuddalore and Pondicherry coasts. The structural damages were studied village wise and categorized as maximum, moderate and least affected areas. As far as the natural resources are concerned, the changes in geomorphology, land use/ land cover, soil and water have been studied. On the basis of the same, the risk maps were also generated in GIS environment.

Keywords: Tsunami, Damage Assessment, Remote Sensing, GIS, Cuddalore, Pondicherry

Abstract

Geomatics (Remote Sensing and GIS) based tsunami damage assessment was carried out for Nagapattinam coast as a part of All India Coordinated Programme of NRDMS, Department of Science and Technology, New Delhi. The paper discusses the methodology and the inferences made for Nagapattinam region, Sirkali block and north Poigainallur panchayat village, holistically for the former and as case studies for the latter two. The regional studies show that the coastal geomorphology has played a significant role in tutoring the tsunami inundation and the damages with beach, dunes, tidal flats, backwaters and rivers / streams facilitating the inundation of tsunami. The studies in Sirkali block show the similar role of geomorphology, but the damage assessment carried out for Water bodies, soil and ground water show appreciable damage to Aquifer in the form of saltwater mixing / intrusion due to tsunami. Detailed geospatial data bases were generated village wise too. On the basis of the studies, possible remedial strategies were also suggested.

Keywords: Remote Sensing, GIS, Tsunami 2004, Damage Assessment, Tsunami mitigation, Nagapattinam.