eChapters

Introduction

Groundwater investigation has a long history. In the past a waterman in the village would walk around the investigation area with a Y shaped wooden fork and identify the location for digging the wells. Certain trees and organic landforms like termite mounds were considered as indicators. The native intelligence of local topography should have played a role in identifying potential location. Successful or otherwise the method can be said to lack scientific objectivity. The optimal groundwater surveying method is no doubt drilling. This method ensures that all necessary information is being brought up from the geological formations. However, in order to obtain a desired degree of information from the subsurface of an area, drilling alone is normally not a feasible alternative.

There are a number of efficient and inexpensive geophysical surveying methods available to the hydrogeologist. It is worth noting at this point that these are, without exception, indirect methods. This implies that no method measures directly what we are actually looking for. With geophysical surveys, the target features are therefore invariably associated features. This implies that unless we understand the water context of these features, our geophysical surveys will be less than meaningful.

Objective methods of investigating groundwater are discussed in this chapter.

Introduction

The science of hydrogeology is defined as hydrology with emphasis on geology. This chapter is to refresh your geology knowledge. The key words are highlighted to assist a quick review.

The Crust and its Composition

The thin outermost layer of the earth is called the crust and ranges in thickness from about 8 km under the oceans to about 25 km on land. It extends under both oceans and continents, and forms the source for all the soils, vegetation, and gases in the atmosphere.

The crust is primarily composed of two elements: silicon and oxygen which account for 75% of the earth’s crust. Note that these are the two elements found in quartz (e.g., sand), which suggests this is the most common of all minerals.

Introduction

Water preceded all forms of life on earth and is believed to be the very origin of all organic life forms. For ages water was forming oceans, separating landmasses and shaping the terrain. It further influenced the emerging atmosphere of the young planet. The first organism formed and began to evolve in the primeval oceans. Mankind entered into the scene several million years later. The history is rather too long and infinitely complex. Variety of models with different degrees of certitude and consensus attempt to cogently explain what could have happened. But in spite of all the differences on the course of evolution, there is a universal consensus that water played a decisive role in the changes.

Across the globe, mankind managed to establish different civilizations with dissimilar cultural and material advancements much later. But then invariably all civilizations considered water holy and water bodies were sacred places. Holy wells, springs, rivers, cenotaphs were held in awe all through human history. The mysterious properties of water are studied from time immemorial. And water indeed is a strange compound! Availability of water for consumption and agriculture has determined the zenith and nadir of surviving and extinct civilizations.

Ancient Indian temples as part of design, have a prominent sacred well or a pond with an associated purana/myth narrating the mystical properties of the theertha / waterbody. It is still is a living tradition. In the west wishing wells survive from remote antiquity.

5.1    Population Growth
    
5.2    Exponential Growth
    
5.3    Population Explosions
    
5.4    Over Population
    
5.5     The Causes of Rapid Population Growth
    
5.6    Ways and Means to Solve Over Population
    
5.7    Environment and Health
    
5.8    Family Welfare Programme
    
5.9    Human Rights
    
5.10    Child Welfare
    
5.11    Women Welfare

4.1    Urban Issues
    
4.2    Environmental Ethics - Issues and Possible Solutions
    
4.3    Water Conservation
    4.3.1 Rainwater Harvesting
    
4.4    Greenhouse Gases and their Sources
    4.4.1 Climate Change
    4.4.2 Global Warming
    4.4.3 The Greenhouse Effect
    4.4.4 Consequences of the Greenhouse Effect
    4.4.5 Acid Rain, 176
    
4.5    Ozone Layer Depletion
    
4.6    Nuclear Accidents
    
4.7    Waste Reclamation
    
4.8    Consumerism and Waste
    
4.9    Forest (Conservation) Act 1980
    
4.10    Wildlife Protection Act
    
4.11    The Air  (Prevention and Control of Pollution) Act 1981
    
4.12    Water (Prevention and Control of Pollution) Act 1974
    4.13    The Environment (Protection) Act, 1986
    4.14    Environmental  Laws

3.1    Air Pollution
    3.1.1 Classification of Air Pollutants
    3.1.2  Properties of Air Pollutants
    3.1.3  Health Effects
    3.1.4 Particulate Pollution Control Equipments
    3.1.5 Gaseous Pollution Control Equipments
    
3.2    Water Pollution
    3.2.1 Causes of Pollution
    3.2.2 Origin of Wastewater
    3.2.3 Waste Water Composition
    3.2.4 Types of Water Pollutants
    3.2.5 Basic Processes of Water Treatment
    
3.3    Land
    
3.4    Marine Pollution
    3.4.1 Sources and Effects of Marine Pollution Toxics
    3.4.2 Control Measures
    
3.5    Noise
    3.5.1 Effects of Noise
    3.5.2 Major Noise Sources
    3.5.3 Noise Control Measures
    
3.6    Thermal Pollution
    3.6.1 Effects of Thermal Pollution
    
3.7     Nuclear Hazards
    3.7.1 Nuclear Weapons
    3.7.2 Types of Nuclear Bursts
    3.7.3 Nuclear Injuries
    3.7.4 Residual Radiation
    
3.8    Nuclear Waste and their Treatment
    
3.9    Solid Waste Management
    3.9.1 Role of Human in Prevention of Pollution
    
3.10    Disaster Management
    3.10.1 Floods
    3.10.2 Earthquake
    3.10.3 Cyclone
    3.10.4 Landslides

2.1    Ecosystem
    2.1.1 Major Components of Ecosystems
    2.1.2 Energy and Matter Flow in Ecosystems
    2.1.3 Various Types of Ecosystems
    
2.2    Biodiversity
    2.2.1 Genetic Diversity
    2.2.2 Species Diversity
    2.2.3 Ecosystem Biodiversity
    2.2.4 Values of Biodiversity
    2.2.5 Threats of Biodiversity
    2.2.6 Endangered and Endemica Species of India
    2.2.7 Biodiversity Conservation

1.1     Forest Resources
    
1.2     Uses of Forest
    
1.3     Deforestation and its Effects
    
1.4     Water Resources
        
    1.4.1 Water Conflicts
    1.4.2 Dams Conflicts
    
1.5    Drought
    1.5.1 Regions of Drought in the World
    1.5.2 Effects of Drought
    
1.6     Flood
    
1.7    Environmental Effects of Mineral Resources
    
1.8    Food Rseources
    1.8.1 Technological Improvements in Food Production
    1.8.2 Environmental Issues Related to Increased Production
    
1.9    Overgrazing and its Effects
    
1.10    Impacts of Intensive Farming on Soil and Water Resources
    
1.11    Effects of Agricultural Chemicals on the Environment
    
1.12    Energy Sources
    
1.13    Waterlogging
    
1.14    Land Resources
    
1.15    Land Degradation
    
1.16    Soil Erosion
    1.16.1 Types of Erosion
    
1.17     Desertification
    1.17.1 Causes of Desertification
    1.17.2 Effects of Desertification
    
1.18    Conservation of Natural Resources
    1.18.1 Conflicts
    1.18.2 Challenges and Methods

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

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.

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.

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

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.

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.

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).

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 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

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 groundwater targeting in hard rock aquifer systems is complex, because of the heterogeneity of the aquifer systems. The ground water mobility and stability in such aquifer systems varies because of the lithology, folded structures, fracture density, geomorphology, slope etc., These occur in various permutations and combinations and control the overall water holding and conducting capacity in different parts of the aquifer systems. Hence, one needs to analyse all the data so as to understand and bring out precise spatial models on the groundwater probability in hard rock aquifer systems. In the present study, the authors have carried out GIS based appraisals to understand the relation between the lithology and groundwater movement in hard rock aquifer systems of parts of Central Tamil Nadu covering 1300 sq.km. In the said study, GIS images were generated on the maxima zones of various aquifer parameters such as water level, width of aquifer depletion, transmissivity, permeability, specific capacity, storage co-efficient, optimum yield and recovery rate. These were overlaid with the lithology GIS image. Such an analysis has shown that, in general, the fissile hornblende biotite gneiss appears to have some control over the groundwater systems.

Abstract

The groundwater behaviour in hard rock aquifer systems has always remained enigmatic owing to the heterogeneity of the aquifer systems. This is the reason why there are a lot of failures in groundwater targeting and management in hard rock aquifer systems even after the employment of many modern technologies. For precise groundwater targeting in hard rock aquifer systems various parameters like lithology, the type and the degree of structural deformation, the degree of weathering, geomorphology, etc., will have to be analysed which involves spatial analysis of voluminous data. In the sphere of spatial modelling, GIS plays an important role. Hence, a newer study has been carried out in parts of Madurai, Dindigul and Theni districts, Tamil Nadu, to identify the groundwater provinces and their functions using GIS. In the said study, GIS images were generated on the groundwater targets through GIS integration of transmissivity, permeability, storage co-efficient and water level. Such GIS image showing groundwater maxima was overlaid with GIS image of fracture maxima, subsurface geology maxima and the geomorphology maxima and thus by various GIS based spatial manipulations, aquifers controlled by structure, geomorphology, subsurface geology, and combinations of the above various variables were brought out. This has provided potential method for precise targeting of groundwater.