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Humane slaughter is an act of killing the food animals in such a way as to cause the minimum stress or distress to the animal. To achieve this objective animal must be rendered insensible instantaneously and remain insensitive to pain until there is a complete loss of brain responsiveness due to exsanguination. The unconsciousness in animals is induced by stunning procedures which are varying in number. The method of stunning primarily based on species, breed, age, sex, kind and mental state of animals. Stunning is essential to safeguard the feelings and anxieties of animals. It facilitates maximum bleeding from the animals because animal becomes unconscious after stunning. To make animal unconscious before bleeding is not only essential for animal welfare point of view but it is legislation in many countries.

The immune system protects the body from harmful substances by recognizing and responding to antigens. Antigens are the protein molecules which are present on bacteria, virus, fungi or some other microorganisms.Some toxins can also be antigens. These antigens are recognized by immune system. The destruction of antigens by producing antibody is called antibody-mediated immune response. As antibodies are present in the body fluids i.e. humors,this type of response is called humoral immune response.

Humoral immune response is the immune response which is mediated by antibodies.. It is called humoral immune response because antibodies are transferred with the ‘humour’ that is fluid or blood. Antibodies are the proteins produced by B lymphocytes.

It is well known that organic matter plays a unique role in the binding of pesticides in soil, and that this phenomenon is usually the most important cause for interaction of pesticides in the soil environment. Fulvic or humic acids are most commonly associated with the binding interactions. Binding can take place with either the original pesticide or a transformation product, the reaction being induced by abiotic or biotic agents (microbial or plant enzymes). The reactions or processes involved are apparently the same as those responsible for the formation of humic substances, i.e., for the humification process.

The synthesis of humic substances is the least understood and the most intriguing aspect of humus chemistry. Studies on this subject are of enduring and continued research. Several pathways have been identified for the formation of humic substances during the decay of plant and animal remains in soil, the main ones being shown in Fig. 26.1.

6.1. Humus

Fraction of organic matter.

Complex and resistant mixture of brown or dark brown amorphous and colloidal organic substance.

6.2. Humus formation

1. Decomposition: Chemicals in the plant residues are broken down by soil microbes.

Simpler chemicals are metabolized into new compounds in the body tissue of soil microbes.

New compounds are subjected to further modification and synthesis as the microbial tissue is subsequently attacked by other soil microbes.

History of human civilization initiated with the struggle against hunger, it flourishes with the fight against poverty and turns oblivious with absence of voices being raised against these two bio-social lethal. If hunger is a pain, poverty is an agony, then, keeping silent against this carcinoma of civilization is no doubt a crime. Is it that poor people are put to an insurmountable silence by the ruthless hegemonies of political economy, or, they are silent, that’s why they remain poor? Silence has been the lethal enzyme in transforming poverty into hunger, and, offers to a socio- chemical bond, poverty-hunger-silence; the bond that remains non-breakable as on date. Economists lament for poverty, nutritionists regret hunger, but the issues of silence and its cohesion to both hunger and poverty has seldom been scholastically delved into or dealt with. We can hope, a desperation of wishful thinking as it may be, shall drench the researchers who think and feel to explore a missing link between hunger and poverty, the silence or the social anemia of voices.

INTRODUCTION

The concept of hurdle technology has been developed as a new way to realize safe, stable, nutritious and economical foods. It employs combination of different preservation techniques to achieve a multi-target, mild but reliable preservation of foods. The application of hurdle technology in food preservation is increasing rapidly worldwide. Over the years, insight into the hurdle effect has been broadened and the application of hurdle technology has been extended. A better understanding of the occurrence and interaction of food preservative factors (hurdles) in foods is the basis for improvements in food preservation. If the hurdles for the microbes are known, the microbiological stability and safety of this food might be optimized by changing the intensity or quality of these hurdles. Using the proper combination of hurdles, it is possible to improve not only the microbial stability and safety but also the sensory and nutritive quality as well as the economical aspects of food. The hurdle concept is also referred to as food preservation by combined methods, combined process, combination preservation or combination processing techniques. The hurdle effect is of fundamental importance for the preservation of foods. The illustration of hurdle effect was first introduced by Leistner in 1978. Based on the understanding of hurdle effects, the concept of hurdle technology was derived (Leistner 1985).

Hybrids are produced by crossing two genetically diverse parents variety. Hybrid vigour is at its maximum in the F₁ generation and hence highest emphasis is placed on the F₁ hybrids. Hybrid varieties leads to maximum exploition of heterosis as compared to any other varieties. Beal in 1880 recommended the use of F₁ varietal crosses of maize for commercial cultivation.

Mangelsdorf (1951) has opined that hybrid corn has been the most far-reaching development in applied biology. Hybrid cultivars have contributed enormously to world’s food and feed resources. Although dramatically successful at first in corn, hybrids have spread to several other crops both in cross-pollinated and self-pollinated species. Their use is likely to spread more in time to come. Hybrid varieties are those in which F1 populations are used to produce commercial crop. Parents of F1 may be inbred lines, clones, varieties, or other populations. Hybrid breeding is historically rooted in development of hybrids in corn and therefore most of the issues covered in this section relate to hybrid breeding in maize.

The term hybrid or hybrid variety is used to designate F1 populations that are used for commercial plantings. Such F1 populations are obtained by crossing clones, open-pollinated varieties, and inbred lines that are genetically dissimilar. Historically the first attempts to make practical use of fortunate mating system of maize came late in the nineteenth century by W. J. Beal in Michigan, stimulated by Darwin’s work on inbreeding and outcrossing. Beal suggested use of F1 varietal crosses to exploit heterosis for commercial crop. The hybrid seed was to be produced by detasseling alternate rows. It was George Harrison Shull (1909) who first suggested a pure line method of corn breeding based on inbred lines obtained by continued self-fertilization and the use of F1 hybrids between these inbred lines for the production of commercial crop. His proposal was to make use of single crosses (hybrids between two inbred lines) based on the superior performance of the hybrids in various combinations between the inbred lines.

Hybrid vigour in plants has long been noted, and the first suggestion that it be exploited in vegetables was by Hayes and Jones in 1916. F1 hybrid eggplants were used on commercial scale in Japan before 1925. Demonstration of the value of hybrids in corn in the early 1920’s gave impetus to a few exploratory studies in other crops. Methods of its application to large scale field production of hybrids in vegetable crops were first proposed in 1932 using the self incompatibility system in cabbage and in 1943 using the cytoplasmic genetic male sterility system in onion. Today hybrid varieties are common in several vegetable crops viz., sweet corn, onion, tomato, summer squash, ordinary cabbage, cucumber, watermelon, muskmelon, asparagus, sweet pepper, chilli pepper, spinach, broccoli, Chinese cabbage, eggplant, Brussels sprout, Chinese radish, red beet, celery, bottle gourd, bitter gourd, okra, etc. India figures prominently in commercial exploitation of heterosis in vegetable crops like cabbage, tomato, okra, watermelon, muskmelon, eggplant, bottle gourd, bitter gourd and cucumber.

INTRODUCTION

Information services are keys to the development of agriculture education, research and extension education in India. The services are rendered by the agricultural department, university, college and ICAR institute libraries. In changing scenario the users of libraries access the information themselves from various sources such as computer, internet, television, e-governance, videoconferencing, call centers, mobile phones and other electronic sources from anywhere, at any time as and when required.

Agricultural trends are changing everyday with the development of new research techniques and technologies and in support of this a heterogeneous knowledge is available in the form of various electronic sources. To make the best of emerging technologies in agriculture, it is vital that agricultural students, scientists, research scholars, academicians, extension workers, agriculturalists receive continuous information on education, research, extension work, training and to the cultivators on topics such as pesticide management, use of better seeds, irrigation and use etc. for the development of farm and farming. With the introduction of new technology that affects both their processes and products, libraries become more and more hybrid organizations. Hybrid libraries are mixes of traditional print material like books and magazines, as well as electronic based material such as downloadable audio books, electronic journals, e-books, etc. Because of this shift, libraries face many challenges, the most important of which is the competition for scarce resources. In this competition libraries have to change the allocation of resources from the more traditional processes like circulation to more value added processes like direct self-services to their patrons. The FAO is also a source of knowledge and information, providing behind the scenes assistance to help people help themselves.

Floral Biology and Crossing

Pearl millet spikelets bear 2 types of florets, one being bisexual and the other staminate. A singIe pistil with 2 feathery and 3  anthers is enclosed between the lemma and palea. The unisexual staminate florets are sessile and borne below the bisexual flowers. These have 3 anthers and lack the female organs. Pearl millet is a highly protogynous species and thus  highly cross pollinated.
 
The time of panicle exertion from boot leaf varies in inbreds and hybrids. Bhatnagar and Kumar (1960) observed that spike takes 6 days to emerge from the sheath with the maximum emergence on the fourth or fifth day. The stylar branches protrude first from the florets at the tip of the head and gradually proceed downwards. Most of the stylar branches on the earheads emerge by the third day. There exists a great variation in the time taken for the complete emergence of the styles in the hybrids than in the inbred lines (Tewari et al.,1971). Anthesis in pearl millet is completed in two phases. The first involves the bisexual florets while the second involves staminate florets. It has been generally observed that the anthers in the sessile male florets emerge 2-3 days after the anthers have emerged in the bisexual florets. Thus most heads continue to shed pollen for 4-6 days.The largest number of anthers emerged between 8 PM and 2 AM. Environmental factors like temperature and humidity have significant role in the anther emergence.

Hybrid Rice

People’s Republic of China announced the successful development and use of F1 rice hybrids in the late 1970s. The first hybrid rice combinations were put into commercial production in China in 1976. Since then commercial exploitation of hybrid rice attracted the attention of researchers around the world. It is accepted that about 20% yield advantage of hybrid rice would be usually required to meet the extra cost of seed production and the future rice demands of a growing world population. Realizing the prospects of hybrid rice, IRRI intensified research on this and organized an ‘International Symposium on Hybrid Rice’ on 6-10 October 1986 at the Hunan Hybrid Rice Research Centre, Changsha, China where Prof. Yuan Longping and his co-workers had made their names in development of hybrid rice. The proceedings were brought out in form of a book entitled ‘Hybrid Rice’ in 1988 by International Rice Research Institute, Philippines. This book documents the information exchanged, and presents for the first time, in English, much of the Chinese literature on hybrid rice.

Squashes and pumpkins are vegetable crops of the genus Cucurbita. They are grown in temperate, subtropical and tropical regions of the world. These crops are common elements in home gardening and subsistence agro-ecosystems in most countries and are produced on commercial scale in some countries. The economic botany, genetics and evolutionary history of Cucurbita has been reviewed by Whitaker and Davis (1962) and Whitaker (1974).

India is the second-largest producer of vegetables in the world (FAO, 2021). Its diverse soil and climate condition provides ample opportunity to grow a variety of crops (be it tropical, semi-temperate, or temperate type). Vegetables form a significant part of the total agricultural production of the country. India grows vegetables in an area of 10.86 mha with annual production of 200 million tonnes (NHB, 2021). Vegetables alone contribute 66.97 % of the total horticultural production (341.63 million tonnes). During 2021-22, India exported vegetables worth Rs. 5,745.54 crore. The growth in vegetable production is largely due to an increase in productivity of average productivity is 18.18 tonnes per hectare, The increase in productivity has led to improved per caput availability of over 250g.

Improved production technology is an integral part of hybrid seed production technology, which is a very high venture practice. This is because like several factors (climate, availability of parental lines and technical labour etc), success of hybrid seed production also depends on the success of crop management in the hybrid seed production field

A hybrid is the first generation progeny of a cross between two genetically different identical inbred lines. The individual lines are known as inbreds.  Ineffective cross-pollination is a major constraint in a commercial production of hybrid seeds in many crop species. In such crops manual pollination is the way to produce hybrid seeds. Eg. Cotton. In the case of rice it is highly self-pollinated crop and cross-pollination is a big problem. The increased vigour, uniformity and yield of F1 hybrid have been exploited in most crops where the pollination system allows for convenient and economic cross hybridization.  This system is called breeding tool in exploiting the hybrid vigour.

The term heterosis from Greek means hetero different, osis-condition was coined by skull (1914).

Heterosis or hybrid vigour, refers to the increase or decrease in vigour of off spring (hybrid) over parents. Usually, theses two terms are used synonymous.   But hybrid vigour refers to increased vigour; Heterosis both increased and decreased vigour.

Superiority of the hybrid as hybrid vigour and the mechanism by which this superiority is developed is heterosis (Rangaswamy, 1998).

Hybrid Seed Production Technology At a Glance

3.1. Natural cross-pollination

Breeding procedures in any plant species of economic importance are guided by its reproductive system particularly, pollination mechanism. In the cereal crops such as maize, pearl millet etc., where cross-pollination is facilitated by wind, the breeders have developed schemes for commercial exploitation of dominance and epistatic genetic variation through hybrid and population breeding. In contrast in self-pollinated crops, the efforts are always made to exploit additive genetic variation primarily through pedigree and mass selection.
 
In pulses, self-pollination is a rule and pigeonpea is no exception. However under field conditions, occurrence of hybrid plants in the populations is not uncommon; and it happens due to some degree of natural out-crossing that took place in the preceding generation. This type of partial natural out-crossing in pigeonpea is affected by a variety of insects (Fig 10) which forage on its large flowers to collect the nectar. These minor incidences of out-crossing are the primary source of varietal deterioration. Recently, the pigeonpea breeders converted this constraint into an opportunity for genetic enhancement of yield through exploitation of hybrid vigor and developing commercial hybrids.

Heterosis

The superiority of F₁ hybrid over both its parents in terms of yield or some other characters or heterosis is increased vigours, growth, yield or function of a hybrid over the parents, resulting from crossing of genetically diverse organisms. The term heterosis was first coined by Shull in 1914. Generally heterosis manifested as an increase in vigour, size, growth, yield or some other characteristics. But in some cases, hybrid may be inferior to the weaker parent this is also regarded as heterosis.

1. TECHNIQUES OF HYBRID SEED PRODUCTION

1.1. Field crops

Table 1: Techniques of hybrid seed production in field crops

Hybrids are released for commercial cultivation either by the Central or State Varieties Release Committee. The release of a hybrid for commercial cultivation is based on conclusive demonstration of its superiority over the best existing hybrids (included as check in evaluation trials) in yielding ability or in some other features of economic importance, e.g. abiotic and biotic stresses etc. Due to above reason, hybrids are extensively evaluated for their performance, resistance to diseases and insects, and quality in multilocational trials. The multilocational trials are conducted under All India Coordinated Vegetable Improvement Projects, which play a key role in testing, identification and release of new hybrids. Before release of hybrids, three activities and operations are involved. These are:

India has emerged as the second largest producer of vegetables 176.17 mt after China 573.93 mt in the world and is gradually striding towards achieving food and nutritional security at national level. The average productivity of vegetable crops is 17.6 t/ha (NHB, 2015) which is comparatively lower than the productivity of China (23.4t/ha), Spain (39.3t/ha) and USA (32.5t/ha). The lower productivity could be attributed to limited use of quality seeds, inefficient production management, impact of biotic stress and climatic factors during crop production. Among the limiting factors limited availability of quality seed is one of the important factors. Since, the performance of other inputs is also depend on the quality of seed. At present the seed replacement rate among vegetable crops is around 25%, whereas highest in cabbage (>90%) followed by tomato, capsicum, bitter gourd, muskmelon, bottle gourd etc.The use of hybrid seed is in increasing due to higher productivity, tolerance to biotic and a biotic stresses and better market value than the open pollinated varieties but the higher price of the hybrid and their availability is still a constraint in adopting the use of hybrid seeds among small and marginal farmers.

Ash gourd (syn:wax gourd, winter melon, white gourd, white pumpkin, ash pumpkin, Chinese preserving melon and hairy melon) is a vegetable belonging to family Cucurbitaceae and genus Benincasa with only one cultivated species, Benincasa hispida (Thunb.) Cogn. (2n=2x=24). Ash gourd is an important vegetable especially in the Indo-China region, which is also the major producer of ash gourd (Rubatzky and Yamaguchi, 1997), but it is also a potential crop of tropical Africa and America (Sirohiet al., 2005).

Hybridisation

Hybridisation occurs when two species cross to form a new species. If they are named before their hybrid nature has become apparent, the names would become invalid as soon as the hybridity of the specimen has been established.

Hybridism can be of three types:

1. Sympatric Hybridisation

When individuals in two regions overlap in an otherwise well-defined species, they are called sympatric hybridisation. This is common in bird of paradise and humming birds. This hybridisation is listed as cross of two parental species.

14.1 Introduction

The mating or crossing of genetically dissimilar individuals is called hybridization. Hybridization results in recombination that in turn widens the spectrum of variation among individuals. So, the reason for genetic diversity in progenies of crosses is the formation of new combinations of genes. This newly created variability is then channelized into development of better cultivars.

The importance of pure line selection as a method of breeding started decreasing when plant breeders felt that the genetic variability existing in the land races of self-pollinated crops had been almost completely exploited and there was little chance for further improvement in these crops by using pure line breeding. Therefore, no option was left for plant breeders except to cross diverse individuals and combine together desirable characters in a single genotype from two or more parents. The planned hybridization which could avoid self-pollination and chance cross-pollination, soon became the main feature of almost all plant breeding programmes.

The mating or crossing between two genetically dissimilar plants or lines is known as hybridization. In other words, hybridization is an artificial controlled pollination in which pollen grains of desired male parent is transferred on the stigma of the desired female parent.

Objectives of Hybridization

To create genetic variability, which is pre-requisite for crop improvement programme.

To transfer one or more characters into single plant.

To know the inheritance of the characters.

To estimate the general combining ability of the parents and specific combining ability of the crosses.

To exploit and utilize the hybrid vigour.

To produce hybrid/synthetic varieties.

The genus Hydrangea is the best-known member of family Hydrangeaceae tribe Hydrangeae from the Asterid order Cornales. With more than two centuries of horticultural trade, Hydrangea cultivars are among the most popular ornamental shrubs worldwide (McClintock, 1957 and Kardos et al., 2009). Hydrangea (Hortensia) is a very popular ornamental plant for gardens. Hydrangeas occur most often on partly shaded but open slopes, rock edges, cliffs, roadside banks, edges of woods, or in moist open woods. Usually, restricted to the more moist, protected slopes. Recently it is commercialized for the production of cut flowers (Sacco et al., 2012). In India is widely grown in hilly areas.

The genus Hydrangea is the best-known member of family Hydrangeaceae tribe Hydrangeae from the Asterid order Cornales. With more than two centuries of horticultural trade, Hydrangea cultivars are among the most popular ornamental shrubs worldwide (McClintock, 1957 and Kardos et al., 2009). Hydrangea (Hortensia) is a very popular ornamental plant for gardens. Hydrangeas occur most often on partly shaded but open slopes, rock edges, cliffs, roadside banks, edges of woods, or in moist open woods. Usually, restricted to the more moist, protected slopes. Recently it is commercialized for the production of cut flowers (Sacco et al., 2012). In India is widely grown in hilly areas.

ORIGIN AND DISTRIBUTION

The species of genus Hydrangea L. grow naturally in temperate areas of Eastern Asia, including some Pacific islands adjacent to Eastern Asia (Philippines, Taiwan, etc.), in temperate Northeastern America, in subtropical Middle and South America (McClintock, 1957). Throughout the eastern United States, ranging from the middle Atlantic States southward through the Southern Appalachians, and westward into the Ozarks and lower Midwest, numerous populations of shrubs with large, ovate, opposite leaves and compound cymes of small white flowers are en-countered. These are the wild hydrangeas.

SPECIES

Hydrangea is a genus of about 75 species of flowering plants native to southern and eastern Asia and North and South America. Most are shrubs 1-3 tall, but some are small trees and others lianas (Sacco et al., 2012). Species differ qualitatively in flavonoid constituents.

Three types of water movement within the soil are recognized. They are

1. Saturated flow
2. Unsaturated flow
3. Water vapour movement

Saturated flow

This occurs when the soil pores are completely filled with water. This water moves at water potentials larger than 33 kPa. Saturated flow is water flow caused by gravity’s pull. It begins with infiltration, which is water movement into soil when rain or irrigation water is on the soil surface. When the soil profile is wetted, the movement of more water flowing through the wetted soil is termed percolation.

Hydraulic conductivity can be expressed mathematically as

Hydraulic pumps are the devices utilized to transfer pressure energy to liquids at the expense of electrical energy. The electrical energy is transferred to a motor which converts it into mechanical work and a pump is coupled to the shaft. The pump converts the mechanical energy to hydraulic or potential energy. 

Hydraulic turbines is a device which transforms the hydraulic energy or potential energy existing with the working medium to mechanical energy. The working medium is normally water which run the hydraulic turbine. The hydraulic energy is available with water by virtue of its height or altitude. The water which flow through the mountains is stored by constructing a dam or reservoir.

In drip irrigation water is distributed throughout the field from a system of pressurized pipelines. The pressure must be sufficient to overcome the frictional losses and elevation differences. The system also deserves discharge from all the emitters and the emitters must dissipate the pressure difference between the inlet to emitters and atmospheric pressure.

The flow through the drip pipes may be laminar or turbulent or a combination of both. The laminar flow is characterized by the layers of cylindrical tubes of which the maximum velocity is at the center about double of the average velocity. The turbulent flows having pulsatory cross current velocities and maximum velocity is about only 1.25 time of the average velocity. Turbulent f lows loss more energy than laminar flow due to development of the cross current velocity.

Reynolds Number

The criterion for distinguishing the flow from laminar to turbulent was developed by Osborne Reynolds (1842-1900) and was named as Reynolds number; Re . The Reynolds number in circular pipes flowing full is expressed as

11.1. Hydraulic system

It is a mechanism in a tractor to raise, hold or lower the mounted or semi-mounted equipment by hydraulic means. All the present day tractors are equipped with a hydraulic control system for operating three point hitches. Some of the tractors are fitted with a hydraulic brake system and a few others are fitted with a hydraulic steering system. Tipping trailers, front mounted loaders or dozers are examples of multi use of hydraulics.

11.2. Principle

The working principle of a hydraulic system is based on Pascal’s law (Fig 11.1.) This law states that the pressure applied to an enclosed fluid is transmitted equally in all directions. A small force acting on a small area can produce higher force on a surface of larger area.

14.1 Introduction

Hydro-electric power is electricity produced by the movement of fresh water from rivers and lakes. Gravity causes water to flow downwards and this downward motion of water contains kinetic energy, that can be converted into mechanical energy, and then from mechanical energy into electrical energy in hydro-electric power stations. (“Hydro” comes from the Greek word hydra, meaning water). At a good site hydro-electricity can generate very cost-effective electricity.

Hydro-climatology is defined as the investigation of the impact of climate upon the waters of the earth. This topic includes hydrometeorology, the water processes of evaporation (surface and near surface), rainfall-runoff, and groundwater studies (Langbein, 1967; Wendland, 1998). Hydroclimatology provides a systematic foundation to assess how the climate system causes spatiotemporal changes in the hydrologic cycle with respect to global or local aspects. Variations in the relationship between the hydrologic cycle and the climate system underlie droughts, floods, and future impacts of global warming on available water resources. Both land and satellite based data and computer programming and modelling contribute to our knowledge of the spatiotemporal changes of physical processes shared by the hydrologic cycle and the climate system (Shelton, 2009).

Abstract

The Mesozoic sediments contribute around 54% of the oil and 44% of the gas reserves of the world (Bois et al. 1982). Indian Mesozoic basins occupy an area of about 400 x 103 sq. km and are characterized as frontier basins under category II - IV. These basins are mostly overlain by the Deccan Traps of Late Cretaceous age and are least explored. Deccan Syneclise is one of the largest Mesozoic basins in India, covering an area of ~ 273 x 103 sq. km. Geophysical studies have inferred hidden sub-trappean Mesozoic sediments with thickness up to 2.5 km. It is considered that requisite heat generation due to Deccan Trap volcanism soon after the Cretaceous sedimentation may have acted as a catalyst in hydrocarbon generation. Surface geochemical prospecting surveys along with carbon isotopic studies have been used to assess hydrocarbon generation potential of this part of the basin. The area adjoining Nandurbar beneath Narmada-Tapti region of Deccan Syneclise was selected for geochemical studies where geophysical studies have shown considerable sediment thickness. Surface geochemical studies indicate the generation of light gaseous hydrocarbons, C1 and SC2+ in the range of 3 to 1187 ppb and 1 to 1449 ppb, respectively. The carbon isotopic signatures of selected soil gas samples dC13 CH4 in the range of - 24 to -39.4‰ PDB) suggest thermogenic origin

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

In Gadilam river basin, groundwater is found in both hard rock and sedimentary terrain and is the most important source of rural/urban drinking water supply. Gadilam river basin has gained its importance due to the presence of Neyveli Lignite open cast mine (NLC), group of industrial estate (SIPCOT), extensive depressurization of Cuddalore aquifer and boreholes of New Veeranam Scheme (NVS) in the downstream of the basin. A total of 178 water samples were collected in four different seasons at various lithologies. The collected samples were analyzed for various physico-chemical parameters using standard procedures. Geochemical indicators of groundwater were used to identify the chemical processes that control hydrogeochemsitry. Interpretation of hydrogeochemical data suggests that leaching of ions followed by weathering and anthropogenic impact controls the chemistry of the groundwater. Isotopic study reveals that recharge from meteoric source in sedimentary terrain and rock water interaction with significant evaporation prevails in hard rock region. This thorough understanding helps us to make judicial usage and to maintain the quality of this commodity.

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

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 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.

Introduction

Water is among the most precious gifts of nature to mankind. Most of the ancient towns of the world grew on the banks of the river, and some of the ancient civilizations are known by the names of rivers. Rivers have always been important sources of drinking water and the means of sustaining human, animal and plant life. Whenever one is dealing with water resources development and utilization, it has to be kept in mind that not only quantity of water but also quality of water is very important. The well being and development of our society is dependent on the availability of water. An increase in groundwater development and utilization for industries and urban water supply has created improper disposal of liquid waste. Defective well constructions, sewage and waste disposal in man made lakes with in the city, open quarries with water and failure to seal the abandoned wells in city area have provided possible openings for downward movement of polluted water into subsurface formations without undergoing the process of natural filtration.

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.

Common groundwater investigations include necessary considerations of the system’s influx sources, flow regime, discharge points and geomorphological characteristics of the area. Often, hydrogeomorphological mapping of an area is required as to determine these characteristics. The primary data can be acquired from the survey of India toposheet map and the satellite images. The secondary data set includes the satellite imageries, the preparation of digital elevation model (DEM) and digitized precipitation maps.

The first step in the procedure of hydrogeomorphological mapping is to calculate the watershed/basin area, which serves as a mask to define the area of interest. The watershed/basin calculation relies on the digital elevation data and assumes that topographic aspect (dip direction of the cell surface) completely controls the extent to which surface flow emanating from each point in the study area can reach the low point in the valley. The calculation of the potential annual recharge of the aquifer combines techniques described above with data for recharge areas, DEM aspect, and precipitation. First, the catchment area of the recharge zones must be calculated in a process similar to the watershed analysis, returning the area associated with the catchment coded as “1”. A simple multiplication overlay with the precipitation data and the catchment areas yields a result giving the amount of precipitation for each catchment cell. Before using the precipitation data, we converted it to meters so as to keep units consistent. The precipitation amounts within the catchment area (i.e. each cell value) are to be summed, yielding the amount of water available for influx into the groundwater system. Finally precipitation per year data can be acquired.

Identifying surface areas of groundwater discharge is based on the observation that such areas provide a relatively constant source of moisture, which is readily exploited by vegetation in semi-arid region. Thus areas with year-round green vegetation are assumed to be indicators of discharge. The relative amount of vegetation in a scene can be estimated by calculating a vegetation index (Reddy et al, 1989 and Tucker 1979).

The world is head98ing towards a water crisis. Africa and West Asia are likely to be worst affected by water scarcity, but with increasing population, water may fall short even in the other parts of the world. According to the recent UN report, the supply of clean and fresh water is depleting at such an alarming rate in some regions, that within 30 years, about two third of population will suffer moderate to severe water stress.

In hydrogeomorphological context of social environment the water is an essential natural resource for sustaining life. The available water resources are under tremendous pressure due to increased demands. The time is not far when water, which is the free gift of nature, will become a scare commodity. Therefore, conservation and preservation of water resources are urgently required to be done at priority basis. Water management has always been practiced in our communities since ancient times. But such practices have faded away during the past few decades mainly due to lack awareness. Hydrogeologists feel that the water harvesting practices must be urgently implemented to overcome the problem of water crises. In India the Ministry of water Resources is endeavouring to make rainwater harvesting a part of every day life in villages and cities as a people’s movement. Hydrogeomorphological aspect of social environment include (a) Social - Cultural -Administrative Consideration (b) Education and Training in Hydrogeology for Professionals and Technicians (c) Education for Farmers and Women (d) Education for Masses. These are described as below:

The beginning of the 20^th century was heralded by methodological revolution in geomorphological studies brought in by Davis (1899). His classical model of geographical cycle defined by him ‘ as a period of time during which and uplifted landmass undergoes its transformation by the process of land sculpture ending into a low featureless plain (peneplain)’ dominated the geomorphological investigations all over the world throughout 1^st half of the 20^th century.

The statistical techniques by Horton (1932 and 1945) brought quantitative revolution in the field of geomorphology when he presented quantitative analysis of morphometric characteristics of fluvially originated drainage basin. Post 1950 geomorphology has undergone vast change in the methods and approaches to the study of landforms, conceptual framework, paradigm and thrust areas of study. The most outstanding contribution to the advancement of geomorphological knowledge in this period is the adoption of quantitative approach based on deductive scientific method to the study of landforms and processes at short spatial and temporal scales (Strahler, 1956 and Schumm, 1956).

Several attempts have been made in the world in past to classify large territories and landforms into morpho-units. Valuable contributions pertaining to landform analysis have been summarized below: Joerg (1914) subdivided North America into natural regions, Fenneman (1914) established physiographic boundaries and gave physiographic divisions of the United States, whereas Anderson (1941) gave physiographic divisions of Columbia plateau. Howard and Spock (1940) and Weaver (1965) presented the excellent ways of classification of the landforms while Wood and Snell (1960) applied the quantitative systems for the classification of the landforms. However, Linton (1951) and Hammond (1954 and 1965) gave techniques for mapping delineating small scale and large-scale landforms.