eChapters

Introduction

Large scale exploitation of groundwater using modern deep well boring technology and powerful pumps is the order of the day in India and elsewhere. Increase in agriculture area and year around cultivation of water intensive crops, frequently failing monsoons (Fig.5.1) all have led to drying up of surface water and increased dependence on groundwater.

Thus, given the scenario of over exploitation of the available groundwater, it is essential that proper storage and management of available groundwater resources be identified.

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

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

Fresh water, a renewable but not an infinite resource, is becoming increasingly scarce. The amount available for use to the world today is almost the same as it was 4500 years ago but global demand has been increasing exponentially. Since 1950, the renewable supply per person has fallen 58 percent as world population has swelled from 2.5 billion to 6 billion. Moreover, unlike oil and most other strategic resources, fresh water has no substitute in most of its uses. It is essential for growing food, manufacturing goods, and safeguarding human health.

According to a World Policy Forum report, the largest and most combustible imbalance between population and available water supplies will be in Asia, where crop production depends heavily on irrigation. Asia today has roughly 60 percent of the world’s people but only 36 percent of the world’s renewable fresh water. China, India, Iran, and Pakistan are among the countries where a significant share of the irrigated land is now jeopardized by groundwater depletion, scarce river water, a fertility-sapping buildup of salts in the soil, or some combination of these factors. Groundwater depletion alone places 10 to 20 percent of grain production in both China and India at risk.

Introduction

All models are but approximations of reality. When we approximate there is always room for uncertainty. The preference of a particular model over the other is the relative degree of uncertainty acceptable to the objective and budget of the study. With the advent of computers, hosts of modeling software promising a lot to the researcher have arrived on the horizon. It is not in the scope of the book to enumerate all the techniques of hydrogeological modeling. Physical modeling using sand tanks was the earliest attempted modeling technique, about 107 years ago. Most recent and significant modeling technique practiced by many in groundwater potential identification is Geographic Information System (GIS) based modeling. After a brief treatment of physical models, concepts of mathematical models and GIS modeling are elaborated. The modeling techniques have involved mathematics and or software specific instructions. Hence it is recommended that relevant text books for individual techniques be referred. This chapter deals more on modeling concepts.

Introduction

Water is one of the most complex natural resources demanding a comprehensive understanding of its inherent features in occurrence and distribution for an integrated planning aimed at optimum development for agriculture, health, industry, power, etc. 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 within 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.

Abstract

Water is an essential and vital component for our life support system. Drought and floods are the extreme events of rainfall and the vagaries of monsoon and hydrogeological framework in the country are highly variable from place to place. The water resources available in the country are also not uniformly distributed. The changing Landuse pattern and population growth and the resultant water resources development has lead to water stress at many places. In such areas, the extraction of excessive quantities of groundwater has resulted in the drying up of wells, damages of ecosystems, land subsidence, salt-water intrusion and other related problems. Agricultural, urban & industrial wastes are increasingly threatening the groundwater quality, which is likely to become a more serious issue in the coming years. Considering the seriousness of the groundwater contamination, Central Ground Water Board has carried out detailed studies in few hot spots in the state of Tamil Nadu. The issues related to the water resources contamination and the findings of the studies in parts of Tamil Nadu are summarized in this paper.

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

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.

10.1 Introduction

During rain or heavy irrigation, a part of the rainfall or irrigated water moves below the effective root zone of the crop which moves further below and adds to the water table lying above the impermeable bed or hard rock which is called as  ground  water  reservoir. At  times  the  accumulated  surface  water  is  also recharged to the soil reservoir both naturally as well as artificially that add to the underlying ground water reservoir. This groundwater is an important source of water for irrigation as well as domestic uses. It is the most abundant fresh water resource of the earth. Underground water reservoirs contain large stock of fresh water resources. Total quantity of groundwater within 800 m distance below  the  ground  surface  is  more than  30  times  the  total  water  in  all fresh water lakes, more than 60 times the total water in soil and other unsaturated rock materials, more than 300 times the water vapour in the atmosphere and 3000 times the average volume of all rivers and rivulets in the world (Lenka, 2001). But the distribution of groundwater is not uniform.

Introduction

In a technology that consistently maintains a fantastic development curve with capabilities doubling up year-to-year, freezing the hardware specification is not easy or very meaningful. GIS (not geography) owes to its genesis and progress to the developments in information technology front. It may be asserted that any and all upgrade in the hardware industry will only add to its own ability to effectively process more and more data and handle more complex routines. The personal computers of today are seen to be adequate to run typical GIS software. A reference hardware specification is discussed here. GIS software development is an involved process but then the software developers have made good use of hardware capabilities available and have released upgrades consistently. Hardware developments are such that they defy a static spcification. However a reference specification as on 2009. An overview of various software packages used in the past as well as present is attempted. ESRI released a new version in 2002 and claimed that their ArcGIS is an “integrated collection of GIS software products for building a complete GIS that enable users to deploy GIS functionality wherever it is needed, in desktops, servers, or custom applications; over the Web; or in the field.” The details are discussed below. While a number of software overviews are available, this text is not aimed at providing a tutorial to any of the software packages nor do the comparisons made are to promote any particular software. Similarly, it is presumed that the reader is familiar with the hardware elements and functionality. Lot of information about the software packages are available on their respective web sites and the reader is exhorted to look for current, additional and in depth information required in the pages. A brief discussion on Liveware or human resource can be found at the end of the chapter.

Abstract

Agroforestry is an ancient practice that farmers have adopted throughout the world. There are innumerable examples of traditional land use practices combining production of trees and agriculture crops on the same piece of land. In India, the organized agroforestry research began in 1979 when a Seminar on Agroforestry was organized at Imphal by the ICAR, New Delhi. As a follow up to this, ICAR launched an All India Co-ordinated Research Project on Agroforestry (AICRPAF) was started in 1983. The diagnostic survey and appraisal revealed that there are enumerable agroforestry practices prevalent in different agro- ecological zones of India occupying sizeable areas. However, spatial technologies like Geographical Information System (GIS), Remote Sensing (RS) and Geographical Positioning System (GPS) have yet to be implemented extensively in this field in India. The spatial technologies have shown great potential in natural resource management through out the world, especially in developed countries in the fields like forest cover mapping, agricultural planning, watershed management, land use planning, etc. In India the agroforestry land use occupy large areas but use of these technologies to estimate area has been initiated in year 2007 with DST sponsored project entitled ‘Spatial and Temporal analysis of agroforestry interventions in North-western India using GIS and Remote Sensing’ The area under agroforestry systems has been estimated/ mapped in two districts viz., Yamunanagar (Haryana) and Saharanpur (Uttar Pradesh), where intensive commercial agroforestry was predominant. Besides, the methodology developed as an out come of this study may be replicated for agroforestry systems existing in other parts of the country.

Keywords: Agroforestry, Geo-spatial, Mapping, Natural Resources, Remote Sensing.

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

The Himalaya is one of the youngest and the richest mountain ecosystems encompassed with a variety of species of both flora and fauna. Varying in climatic conditions coupled with altitudinal gradients and unique topography leads to the formation of different types of forests, which varies from tropical to the temperate and alpine to no timber line zone and snow-clad meadows. The present study aimed to investigate the potential of medicinal plants growing in valleys and mountains of district Doda to cure various ailments of the local inhabitants including animal health care. A total of 113 species belonging to 104 genera and 55 families of angiosperms, gymnosperms and cryptogams (lycophytes and ferns) were recorded and reviewed from published documents used for treatment of different diseases in the regions. Out of the total 113 species, 17 species were of trees, 14 species were shrubs, 78 types of herbaceous plants and 4 species of climbers. Asteraceae, Lamiaceae, Rosaceae, Ranunculaceae, Polygonaceae, Solanaceae, Apiaceae, Pinaceae, Fabaceae and Berberidaceae were recorded as the dominant families of the study area. The data were collected while interacting with local people as they possess rich traditional knowledge regarding the use of different herbal plants and medicine.

A review on historic occurrences of tsunamis in the Indian Ocean and their associated characteristics followed by detailed characterization of genetic causes of recent tsunamiarepresented in this chapter. Althoughsubmarineearthquakes occur very frequently, resultant tsunami and its strength relied on many factors including transformation of energy into the ocean water, area of rupturing of ocean floor, duration of rupturing, accompanying submarine slides, kind of material at focus of earthquakes and type of faulting. The direction of tsunami wave propagation plays the decisive role in deciding sites of impacts. Perfect blend of all these parameters is required to make a submarine earthquake to generate devastating tsunami, which is relatively rare in geological history. This is the reason why although there were as many as 77 tsunamis that occurred in the Indian Ocean region during historic past, the recent one of 26th December 2004 is deadly and rare geological occurrence. However, aftermath effects in terms of volcanic eruptions, coastal high wave activities and change in climatic cycles are recorded since then and require constant scientific vigil.

INTRODUCTION

Tsunami is defined as a sea wave of local or distant origin that results from large-scale seafloor displacement associated with major earthquake or submarine slide or submarine volcanic explosion. Many a times it is incorrectly described as tidal wave or seismic sea wave, as both of these terms mislead in regard to its mechanism of generation. In Tamil Sangam literature, tsunami is cited as “Azhipperalai”. In South America, it is termed as “Maremoto”. Other names for tsunami include “Flutwellen”, “Vloedgolven” “raz de mare” “Vagues Sismique” and Kai e’e. Prevalence of specific terms for tsunami in many such regions and languages itself stands testimony to the fact that tsunami is known to ancient human populations and that tsunami occurred frequently the historics past.

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

Overall geological histories of the Quaternary deltas of all over the world have been studied considerably, to understand the evolution, eustatic – isostatic changes, land – ocean interactive phenomenon, resources, environment etc. But tectonic signatures of these deltas have been less studied, though these have significance in understanding the natural resources, environment and evaluation of natural disasters. In this context, as the state of Tamil Nadu is a low easterly gradient plain, all the easterly flowing rivers have developed well evolved geomorphic features related to youthful, mature and old stages. Such old stages of the rivers are marked by the spectacular development of deltas. These deltas of Tamil Nadu have been studied in detail for understanding the tectonics with the help of visibly seen tectonic and geomorphic features in satellite based remote sensing and ground based data sets. The study has revealed that the upper age limit / ages of these deltas are probably of Middle to Late Holocene and the various tectonic and geomorphic anomalies observed in these deltas obviously indicate the tectonic processes/ phenomena that prevailed during Middle Holocene - till date. The Proto Cauvery delta of Chennai region is witnessing ongoing NE–SW sinistral, NW–SE dextral and E–W vertical tectonic activities. The streams in Ponnaiyar delta are showing persistent southerly migration due to the probable ongoing land subsidence along NE–SW faults in the southern part of the delta. The Cauvery river which has originally developed a broad bird-foot shaped – arcuate delta, has undergone a phase of anticlockwise rotational migration and stabilized in the northern rim of the delta as Coleroon river during 2300–750 Y.B.P. due to the ongoing tectonic emergence in the south of the delta almost since the last 6000 years or so. The Vellar river, in deltaic regime, shows northerly migration due to E–W grabening in the northern part of the delta. Vaigai and Manimuttar rivers are again migrating northerly in their deltaic regions due to the probable land arching to the south of their present day flow. Thus, the paper discusses the post deltaic / Middle -Late Holocene geological processes of Tamil Nadu deltas which are predominated by tectonic activities.

Abstract

Ethnobotany as an academic discipline surfaced in the 19^th century. Traditional medicine is used globally and is of rapidly growing economic importance. In developing countries, traditional medicine is often the only accessible and affordable treatment available. The chapter deals with importance of plants in the life of people, value of collecting the plant samples and adding knowledge to plants based on their economic potential and issues related to ethnopharmacology.

Keywords: Ethobotany, Ethnopharmacology, Drug discovery, Research ethics.

Population Growth
Around 1810, it took all of human history for the population to reach one billion. This quadrupled to 2 billion people in just 120 years (1930). Then, in 45 years, 4 billion (1975). From 4.4 billion in 1980 to 5.8 billion in 1997 and 7 billion now, the world’s population has increased. It is predicted that in less than 40 years, that number will double again to 11 billion. This indicates that more people than ever before are joining the group every day.
The United Nations Population Fund (UNPF) predicts that by 2025, there will be 10 billion people on Earth, and by the next century, there will be 14 billion.
Birth rates have decreased along with mortality rates, although death rates have decreased more quickly. In most affluent countries, there are approximately 1.6 births for every death, but in less developed countries, the ratio is closer to 3.3 births for every death. Every twelve years, a billion more people live on the planet.
Reasons Behind the Quick Population Growth
• A rise in the distribution and production of food.
• Gains in the field of public health
• medical technology, as well as improvements in education and living standards in many poor countries.