eChapters

Abstract

It is evident from the previous studies that, in the crystalline terrain, the Fractures / lineaments act as master conduits for the groundwater movements and also act as favorable loci for groundwater storage. Because of this, the mapping of fracture patterns has become very popular among geoscientists. However, after witnessing failures and the fractures turned out to be water barren at many instances, geoscientists have started concentrating more on understanding the origin and the morphology of the fractures for precise groundwater targeting. In this context, a study has been conducted in parts of Western Ghats in Madurai, Dindigul and Theni districts of Tamil Nadu, South India, using remote sensing and geographic information system (GIS). In the said study, the maxima zones of transmissivity were studied in relation to fractures systems, which are normally reflected as lineaments in satellite images in the area. This study in general indicates that the transmissivity is controlled by the fractures, which are interestingly the active faults of the Quaternary period in the area.

Abstract

The development index and the developmental planning of a Country/Nation mostly depend on its natural resources potential including water resources. The fast emerging Remote Sensing and GIS technology has substantially reduced the problems of water resources management including groundwater. The groundwater is distinctly controlled by western crystallines, central Tertiary sandstone and eastern Quaternary sediments in Pudukkottai district. While the groundwater behavior in crystallines is dominantly controlled by secondary porosity, in Tertiary formations and Quaternary sediments, it is controlled primarily by the primary porosity and by secondary porosities also if these are structurally deformed.

Abstract

Water has become a scarce resource all over the World. Water resources of Earth can be classified as surface water and groundwater in which groundwater is the main source for the drinking, domestic and agriculture. The Pudukkottai district is one of the chronic drought prone areas in Tamil Nadu. But, at the same time, the district is pitted with over 5,400 tanks/water bodies widely distributed throughout in general and clustered more in Vellar delta in particular, as the interlobel depressions have provided basic depressions for the surface water to accumulate. However, these surface water bodies are heavily silted. In Pudukkottai district, there are three divergent aquifer systems, hard rock aquifer system in the western, sedimentary aquifer system constituted by the Tertiary Sandstone (Cuddalore Sandstone) in the central and Quaternary aquifer system constituted by fluvial, fluvio-marine and marine systems in the eastern parts of the district.

Abstract

The paper presents an approach of selecting suitable areas for artificial groundwater recharge structures through remote sensing and integrated terrain analysis by statistical method. The study area “Ayyar basin” is an aquifer system of gneisses and charnockite litho-units in Tiruchirappalli district, Tamil Nadu. The area has witnessed a steady decline in groundwater table. Hence, the scope for artificial groundwater recharge was studied in this area with the help of Tamil Nadu State Council for Science and Technology (TNSCS&T).

Soil acidity is a major constraint for crop production. The production of acid in soils is a natural process, especially in the high rainfall areas. The removal of basic cations especially Ca and Mg, by leaching and erosion results in their replacement by acidic cations, H, Al and Fe on cation exchange sites and in the soil solution, which are in dynamic equilibrium with each other. Soils, that develop from weathered granite are likely to be more acidic than those developed from shale or limestone. Organic matter decay produces H+ in soils, which also contribute to soil acidity. Intensive cropping and use of hybrid & high yielding crop varieties remove large quantities of basic elements essential for their growth i.e. Ca, Mg and K & deplete the soils. Rate of acidification is also accelerated by  faulty fertilizer (especially Nitrogen) management practices.

Soil pH

Danish scientist Sorensen (1909) first used the term pH. The H+ concentration is usually small and is expressed in terms of pH, defined as the logarithm of the reciprocal of the H+ concentration, in moles per litre. The pH scale ranges from 0 to 14, with 7 being neutral. Soil acidity is the concentration of H+ in the soil solution. This is active acidity. Besides, there is a potential acidity, that includes the H+ adsorbed on the colloidal fraction of soil. The pH scale is derived from the dissociation constant of water, Kw:

Soil  is an interface of inorganic and organic componentsof the planet earth, which combines carbon and nitrogen from the atmosphere with different mineral elements of the lithosphere through millions of microorganisms, intercepting energy from the sun and moisture from the hydrosphere and atmosphere. It is a source as well as sink to adsorb, desorb, fix or release mineral elements and gases, decompose organic residues, simultaneously and support the growth of plants. All these natural processes are accompanied by runoff, percolation and evapotranspiration processes of the hydrologic cycle. Thus, soil is a dynamic body that acquires properties in accordance with the forces, which act upon it. Many soil properties emanate from physical, chemical and biologically mediated reactions, where the factors like climate, vegetation, topography and time  influences the processes. Soil reaction is one of the most important chemical characteristics of the soil solution,which has both direct and indirect effects on plant nutrition.

Acid soils are found in India in about 93 million hectares ( Table 1) and they occur in the Himalayan region, the great Indo-Gangetic and Brahmaputra plains, peninsular plateau and uplands and the coastal plains including island eco-systems under varying environmental conditions of landscape, geology, climate and vegetation. Conditions which are conducive for the formation of acid soils, such as high rainfall coupled with high temperature encouraging intense weathering and loss of alkali and alkaline earth metals with a simultaneous accumulation of iron and aluminium hydroxy compounds or the formation of free acidic substances in the humid forest foot hill regions, exist in some region or other in almost all the states in India.  A soil with pH less than 7.0 is deemed as an acid soil (Soil Survey Staff,1951). However, for characterization and classification, acid soils may be defined as those having pH less than 5.5 in 1:1 water extract (Soil Survey Staff, 1999).

The north eastern hill region covers a large share of acid soils of India occupying 14.95 m ha which is a major constraint for sustainable crop production. Acid soil limits the availability of calcium and phosphorus in soil, lowers base saturation and reduces microbial activities in soil adversely affecting the crop growth and yield. About 95 % of the soils of this region, except Nagaland (about 70 %) are acidic in reaction. About 84, 77, 76, 60, 57 and 47 per cent soils of Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Sikkim and Tripura, respectively have soil pH below 5.0 and are considered strongly acidic (Panda, 1998). The soils are highly degraded because of heavy rainfall and removal of top soils. Land slides are also contributing towards land degradation. About 16 % of the area is affected by water erosion (www.india stat.com). About 53.8, 28.2, 42.6, 53.9, 89.2, 60, 33 and 59.9 per cent  area are degraded in Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, respectively. Including Assam, north-east constitutes 80 % of the total area under acid soils of the country. The land use pattern of north-east region is presented in table 1 and area, production, yield of foodgrains and fertilizer consumption are presented in Table 2.

Jharkhand state lies between 21º58’2" to 25º8’32" North latitude and 83º19’05"to 87º55’03" East longitude covering an area of about 7.97 m.ha. and accounts for  2.4 per cent of  the total geographical area (TGA) of the country. It is bound on the east by West Bengal, on the west by Chhattisgarh, on the north by Bihar and on the south by Odisha. Reliable information on the location, extent and quality of soil and land resources is the first requirement in planning for the sustainable management of land resources. The components of land i.e., soils, climate, water, nutrient and biota are organised into an eco-system, which provides a variety of services that are essential for the maintenance of the life support system and the productive capacity of the environment.

Acid soils occupy one fourth of the land in India. The formation and distribution of acid soils depend upon several factors like temperature, vegetation, parent material and hydrological conditions etc. For this reason, these soils have low pH, poor base saturation, high sexquioxide content, which affects the transformation and availability of plant nutrients.  Secondary and micronutrient deficiency as well as toxicity are major problems in cultivation of crops in acidic soils. These soils are generally deficient in Ca, Mg and S and adequate in Fe, Mn and Cu. Apart from the secondary nutrients, Zn, B and Mo deficiencies affect crop production. In lowlands, rice crop suffers from toxicity of Fe. Aluminum toxicity, common in highly acidic soils, also pose major problems in crop production. Management of secondary and micronutrients in acid soils for agriculture is a national priority to achieve food sufficiency and sustainability.

Soils become acidic due to natural  and artificial (anthropogenic) reasons. The natural reasons include their origin from acidic parent materials namely granite, rhyolite, pegmatite and dacite etc. and areas under high rainfall  (rainfall  exceeding evapotranspiration) removing  basic cations through leaching and erosion particularly in coarse textured soils with undulated, hilly and sloping topography. Under natural condition, accumulation of organic matter and its decomposition also releases organic acids into the soil system, turning soils  acidic. The anthropogenic factors    responsible for turning soils  acidic,  are (i) removal of basic cations through crop cultivation, (ii) continuous use of acid forming fertilizers and (iii) acid rain in industrial areas.

Introduction
Remote sensing is the art and science of recording, measuring, and analyzing information about a phenomenon from a distance. Humans with the aid of their eyes, noses, and ears are constantly seeing, smelling, and hearing things from a distance as they move through an environment. Thus, humans are naturally designed to be remote sensors. In order to study large areas of the Earth’s surface geographers use devices known as remote sensors. These sensors are mounted on platforms such as helicopters, planes, and satellites that make it possible for the sensors to observe the Earth from above.

Definition
Remote sensing can be defined as any process whereby information is gathered about an object, area or phenomenon without being in contact with it. Our eyes are an excellent example of a remote sensing device. We are able to gather information about our surroundings by gauging the amount and nature of the reflectance of visible light energy from some external source (such as the sun or a light bulb) as it reflects off objects in our field of view. Contrast this with a thermometer, which must be in contact with the phenomenon it measures, and thus is not a remote sensing device.

Introduction

Although both maps and aerial photos present a “bird’s-eye” view of the earth, aerial photographs are NOT maps. Maps are orthogonal representations of the earth’s surface, meaning that they are directionally and geometrically accurate (at least within the limitations imposed by projecting a 3-dimensional object onto 2 dimensions). Aerial photos, on the other hand, display a high degree of radial distortion. That is, the topography is distorted, and until corrections are made for the distortion, measurements made from a photograph are not accurate. Nevertheless, aerial photographs are a powerful tool for studying the earth’s environment. 

Because most GISs can correct for radial distortion, aerial photographs are an excellent data source for many types of projects, especially those that require spatial data from the same location at periodic intervals over a length of time. Typical applications include land use surveys and habitat analysis. 

This unit discusses benefits of aerial photography, applications, the different types of photography, and the integration of aerial photographs into GISs.

Digital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing. It allows a much wider range of algorithms to be applied to the input data and can avoid problems such as the buildup of noise and signal distortion during processing. Since images are defined over two dimensions (perhaps more) digital image processing may be modeled in the form of multidimensional systems. Introduction to image processing 
Image processing is a method to convert an image into digital form and perform some operations on it, in order to get an enhanced image or to extract some useful information from it. It is a type of signal dispensation in which input is image, like video frame or photograph and output may be image or characteristics associated with that image. Usually image processing system includes treating images as two dimensional signals while applying already set signal processing methods to them.
Image processing is a method to perform some operations on an image, in order to get an enhanced image or to extract some useful information from it. It is a type of signal processing in which input is an image and output may be image or characteristics/features associated with that image. Now-a-days, image processing is among rapidly growing technologies. It forms core research area within engineering and computer science disciplines too.

Introduction

The Global Positioning System (GPS) is a space-based navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. The system provides critical capabilities to military, civil, and commercial users around the world. The United States government created the system, maintains it, and makes it freely accessible to anyone with a GPS receiver. The US began the GPS project in 1973 to overcome the limitations of previous navigation systems, integrating ideas from several predecessors, including a number of classified engineering design studies from the 1960s. The U.S. Department of Defense (DoD) developed the system, which originally used 24 satellites. It became fully operational in 1995. Roger L. Easton, Ivan A. Getting and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it.
 
Advances in technology and new demands on the existing system have now led to efforts to modernize the GPS and implement the next generation of GPS Block IIIA satellites and Next Generation Operational Control System (OCX). Announcements from Vice President Al Gore and the White House in 1998 initiated these changes. In 2000, the U.S. Congress authorized the modernization effort, GPS III. In addition to GPS, other systems are in use or under development. The Russian Global Navigation Satellite System (GLONASS) was developed contem-poraneously with GPS, but suffered from incomplete coverage of the globe until the mid-2000s. There are also the planned European Union Galileo positioning system, China’s BeiDou Navigation Satellite System, the Japanese Quasi-Zenith Satellite System, and India’s Indian Regional Navigation Satellite System.

Introduction

A geographic information system or geographical information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present all types of spatial or geographical data. The acronym GIS is sometimes used for geographic information science (GIScience) to refer to the academic discipline that studies geographic information systems and is a large domain within the broader academic discipline of geoinformatics. What goes beyond a GIS is a spatial data infrastructure, a concept that has no such restrictive boundaries. In a general sense, the term describes any information system that integrates stores, edits, analyzes, shares, and displays geographic information. GIS applications are tools that allow users to create interactive queries (user-created searches), analyze spatial information, edit data in maps, and present the results of all these operations. Geographic information science is the science underlying geographic concepts, applications, and systems.

GIS is a broad term that can refer to a number of different technologies, processes, and methods. It is attached to many operations and has many applications related to engineering, planning, management, transport/logistics, insurance, telecommunications, and business. For that reason, GIS and location intelligence applications can be the foundation for many location-enabled services that rely on analysis and visualization. GIS can relate unrelated information by using location as the key index variable. Locations or extents in the Earth space–time may be recorded as dates/times of occurrence, and x, y, and z coordinates representing, longitude, latitude, and elevation, respectively. All Earth-based spatial–temporal location and extent references should, ideally, be relatable to one another and ultimately to a “real” physical location or extent. This key characteristic of GIS has begun to open new avenues of scientific inquiry.

Applications of Remote Sensing

The era of satellite remote sensing was open in the 1960s when cameras and electronic sensors were mounted on spacecraft. Nowadays there is a big assortment of satellite systems actively recording information about the Earth. A wide variety of imagery is available from satellites. Both active and passive sensors, operating from the microwave to the ultraviolet regions of the electromagnetic spectrum collect a large amount of information about the earth’s surface every day. Each of the systems vary in terms of their spatial, spectral, radiometic and temporal resolution. Those characteristics play an important role in defining which applications the sensor is best suited for. The main benefits of satellite remote sensing are the following:

Introduction

Accumulation of excess soluble salts in the root zone of soils resulting in partial or complete loss of soil productivity is a worldwide phenomenon. The problems of soil salinity are widespread in the arid and semi-arid areas but salt-affected soils also occur extensively in the sub-humid and humid climates particularly in the coastal regions where the ingress of sea water through estuaries and rivers and through ground water movement causes large scale soil and water salinisation. Soil salinity is also a serious problem in areas where ground waters of high salt content are the only source of water available for irrigation. By far the most serious problems of salinity are being faced in the irrigated, arid and semi-arid regions of the world. Our ability to manage salt-affected soils and waters both in the irrigated and in the unirrigated regions will constitute a major effort in meeting potential food requirements. The magnitude of the problem can be appreciated from the following.

Expression of genetic potential for growth and yield of a crop variety is directly dependent upon the environment comprising both climate (weather) and soil components. As discussed in the preceding chapter, the term ‘salt-affected soils’ encompasses a broad group of adverse but distinct soil conditions, namely, saline, alkali (sodic) and acid soils with further variations such as coastal and inland locations as well as arid and water-logged situations (Swaminathan 1977; Bresler et al. 1982). Factors limiting growth and yield of crop plants in various categories of problem soils are different and specific. Likewise, adaptive strategies evolved by plants to cope with the prevailing edaphic stresses, such as salt stress, also vary a great deal as indicated in Table 1. It is not unexpected therefore, that even varieties within a crop often show notable differences regarding tolerance to adverse soil conditions (Epstein et al. 1980; Devine 1982; Shannon 1984; Sayed 1985). Hence, it is essential that the breeder must understand the inherent charaderistics of the problem soil with which he is concerned and should also simultaneously appreciate that basically it is the sensitivity of crop variety, rather than the soil parameters per se, that essentially determines the occurrence as well as the magnitude of actual soil problem (Rana 1977). Since the degree of tolerance (adaptation) of crop varieties to different kinds of salt affected soils is genetically controlled, it is axiomatic that it can be improved through genetic manipulations by adopting suitable breeding procedures.