eChapters

Introduction

It is well known that, over 50% of requirement of food for the entire humanity is obtained from just three crops- rice, maize and wheat though 150 crops are commercialized globally. Ethnobotanically, over 7000 plants species are cultivated or harvested from the wild which represent immense agro-biodiversity. Most of these species are under exploited but have the potential for contributing to food security, health (nutritional/medicinal), income generation and environmental services. Examples include little millets which provide calcium and iron and vitamins like niacin and sulphur containing amino acids, having more fiber than rice and wheat. Some other species which have in the recent past contributed to income generation in Indian arid zone include ber, anola, karonda and gonda. Likewise the perennial grasses in this area are not only source of nutritious fodder but also the grains e.g. gramana (Panicum antidotale) are consumed during famine. They have acquired importance being alternative sources of income as also alternate life support system during crisis. They often have neutraceutical, medicinal uses or often multiple uses. Demand for traditional food in large multi-ethnic cities and metros have brought these species into sharp focus, Hence, these are being viewed now as potential candidate for diversification in the cropping system, conservation of bio-diversity, enhancing the limits of green revolution even during climate change and finally as provider of molecules for curing various ailments of men and animals.

Introduction

Low and erratic rainfall, extreme temperatures, long sunshine duration, high wind velocity, high evapotranspiration, low fertility of soil and paucity of water resources characterize hot arid region of India. Despite these hostile conditions, the region supports a large number of human and livestock population. However, the ever increasing human and livestock population and developmental activities exerts enormous pressure on natural resources and posing serious threat to sustainability of the region. In these hostile environmental conditions, several indigenous agroforestry systems are being practiced by farmers of this region (Shankarnarayanan et al. 1987). The agroforestry, which is a dynamic, ecologically based natural resource management practices that, through the integration of trees and other tall woody plants on farms and in the agricultural landscape, diversify production for increased social, economic and environmental benefits (ICRAF 2000). A number of studies have recognized the multiple benefits of agroforestry that include carbon sequestration, reducing forest degradation, biomass production, food security, income diversification, improvement and maintenance of soil biodiversity, provision of wildlife corridors, and a host of other ecological services and social benefits. In the last three decades, agroforestry has been widely promoted in the tropics as a natural resource management strategy that attempts to balance the goals of agricultural development with the conservation of soils, water, local and regional climate

Introduction

Tree growing in hot arid region is basically concerned with the management of trees for conservation and for limited production objectives like wood for fuel, poles and fencing material; leaves for livestock fodder; and pod/seeds for many types use in human diet. The role of trees to conserve the fragile ecosystems of hot arid regions has been well recognized (Mann and Muthana 1984). The trees also provided so many services to mankind, which make them an intricate part of man-livestock-agriculture continuum, the lifeline of hot arid regions (Saxena 1997). 

Introduction

Throughout the arid zones, there is no dearth of problems, but rapidly increasing desertification (some call it land degradation) is a problem of worldwide dimension. Water is a scare commodity in arid zones. Much of rainfall is lost by evapo-transpiration and as a result, ground water recharged only by seepage through soil profile. However, it is a common phenomenon in arid zones of the world that ground water is frequently used at the rate that exceeds recharge. The situation in arid tropics of India, which is spread over an area of 31.7 million ha, is no more different. Considering the role of agriculture in the social and economic progress of developing countries, the vulnerability of agricultural systems to the impacts of climate change has received considerable attention from the scientific community (Fischer et al. 2002; IISD 2003; Kurukulasuriya and Rosenthal 2003). Much of the available literature suggests that the overall impacts of climate change on agriculture especially in the tropics will be highly negative, although in a few areas there may be minor increases in crop yields in the short term (Maddison et al. 2007). Research on agroforestry as an adaptation to climate change and as a buffer against climate variability is in the process of evolving.

Introduction

Agriculture expanded and forest dwindled. That eventually occurred with the expansion of civilization. Clearing of forests, granted in past, continued in modern times. Cutting of forests reached to such an alarming level that thinking of people turned back to create more forests. Sometimes over extraction of forest resources made forests unstable to yield perpetually according to necessity in future for which forests are turned unsupportive for livelihood and people tried for innovative means to enhance forest productivity in future (Nair 1993). Also with time agriculture faced the similar unfortunate condition towards intensive cultivation. So, peoples’ thinking turned back in agriculture how to make it stable and more supportive for livelihood year after year. Culturally human societies are connected both with agriculture and as well as forests from the time immemorial.

Introduction

Climate change is a big phenomena, it is having a huge impact on agriculture from ancient to present time. It has received wide attention and debate as the public concern has increased about unforeseen change in climate. The impact of climate change on Indian agriculture will be significant since more than 60% of Indian population depends on agriculture for their livelihood with the contribution of agriculture to GDP is approximately 20 percent. In recent decades, human induced changes in climate has the focus of scientific and social attention.

Introduction

Increasing evidence over the past few decades indicate that significant changes in climate are taking place worldwide and its effects are surreal. Major cause to climate change has been ascribed to the increased levels of greenhouse gases like carbon dioxide (CO₂), methane (CH₄), nitrous oxides (N₂O), chlorofluorocarbons (CFCs) beyond their natural levels due to the uncontrolled human activities such as burning of fossil fuels, increased use of refrigerants, and enhanced agricultural activities. Global average sea level has risen since 1961 at an average rate of 1.8 (1.3 to 2.3) mm/yr and since 1993 at 3.1 (2.4 to 3.8) mm/yr, with contributions from thermal expansion, melting glaciers and ice caps, and polar ice sheets. The climatic changes are resulting in erratic weather patterns and the impacts are already being manifested in many parts of the world and coastal agricultural systems are nearing crisis point. The IPCC has projected that during the 21st century the global surface temperature is likely to rise a further by 1.1 to 2.9 °C as per their lowest estimation model and by 2.4 to 6.4 °C as per their higher estimation model.

Introduction

Natural phenomena such as solar radiation, volcanic activity and ocean circulation influence climate and contribute to its variability. Evidence suggests that climate is now also changing as a result of human activities, such as the emission of greenhouse gases and changing land uses. The fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC, 2007) concluded that the global average mean temperature and the frequency of hot extremes, heat waves, and heavy precipitation will very likely increase in response to increased concentrations of greenhouse gases in the atmosphere.

Society will have to make decisions in the coming years about how to adapt to a changing climate. Climate variability and climate change create risks to all sectors of the economy. Climate is already a prime factor in 9 out of 10 disasters, many of which cost billions of dollars and thousands of lives. Effective preparation for the possible effects of climate change requires the engagement of resource managers, planners, public works officials, local managers, community development specialists, businesses, residents, and property owners. The challenge is to provide these diverse stakeholders with trusted, useful, science-based information so that they in turn can make informed decisions. 

The annual milk production in Tamil Nadu during 2009-10 from crossbred cows, non-descript cows and buffaloes were 42.28,7.89 and 7.61 lakh tones, respectively. Tamil Nadu had 59.83 lakhs crossbred female cows in the year 2007 as against 41.47 lakhs in 2003 with an annual growth rate of 9.59 per cent (Anon, 2010). With the increasing crossbred cattle population and average annual production, better management of the high producers becomes a necessity. Production and health of animals depend mostly on environment in which they live. A satisfactory environment for any farm livestock is the one that ensures not only optimal productivity but also meets the health and behavioral needs of the animals. A satisfactory environment is the one that satisfies the following four criteria: thermal comfort, physical comfort, disease control and behavioral satisfaction. The most important environmental interventions done in recent days are those that have been done in housing and other attempts to ameliorate the thermal environment. The effort of the body to maintain a stable internal environment to challenges from widely variable environments was first described by Claude Bernard (1878) and later referred to as homeostasis (Cannon, 1932). An environment in which stressors are minimized would likely be favorable for efficient production of products derived from domestic farm animals and for helping ensure the well-being of those species.

The arid and semi-arid regions of India are drought prone and the availability vegetation of these regions is more acute during summer when the quality of the pastures becomes vulnerable. Small ruminants in the semi-arid regions need to adopt special physiological function to maintain thermal equilibrium. The reproductive efficiency of different breeds of sheep inhabiting in the semi-arid regions of India is relatively low (Arora and Garg, 1998).The nature of nutritional resources and management problems differs with climate, soil and vegetation, the physical process which governs the animals reproductive performance are the same; the female must reach puberty, show behavioral estrus and shed one or more ova which have then to be fertilized. Dietary nutrition promotes the programming and expression of the metabolic pathways that enable animals to achieve their genetic potential for reproduction. Nutrition has an important impact on the reproductive performance in sheep, but the magnitude of the effect on reproduction may vary with the season (White et al., 1983). Sheep are more prone to neglect compared to cattle and often suffer from lack of feed and fodder. The animals during the grazing are exposed to combined stress (Sejian et al., 2010 ab, and 2011) .This leads to decrease in body weight and loss of reproductive functions. Concurrently, Rhind and Mc Neilly (1986) showed that ewes with low body fat reserves had fewer large ovarian follicles and therefore the potential for subsequent maturation and ovulation declined. 

Introduction

Cycling of plant material is required for any production system for biological activity, humus formation and thereby formation of a dark colored top soil. Incorporation of biomass results in production and proliferation of soil biota. But under annual crops compared to forest, production is much less, the biomass is largely removed, the soil is tilled several times each year. Consequently, less food and moisture are available for earthworms, insects, micro-flora and fauna; and their habitats are repeatedly disturbed or destroyed. Therefore, the primary need of our agricultural activities is to feed soil organisms (bacteria, fungi, earthworms etc.) and to regulate their living conditions while protecting them from chemical and mechanical impacts.

Issues of conservation have assumed great importance in view of widespread resource degradation and the need to reduce production costs, increase profitability and make agriculture more competitive. The growing concerns for sustainable agriculture have been seen as a positive response to limits of both low-input, traditional agriculture and intensive modern agriculture relying on high levels of inputs for crop production. Sustainable agriculture relies on practices that help to maintain ecological equilibrium and encourage natural regenerative processes such as nitrogen fixation, nutrient cycling, soil regeneration, and protection of natural enemies of pest and diseases as well as the targeted use of inputs. Agricultural systems relying on such approaches are not only able to support high productivity, but also preserve biodiversity and safeguard the environment. Thus, Conservation agriculture has come up as a new paradigm to achieve goal of sustained agricultural production. It is a major step toward transition to sustainable agriculture. 

Introduction

The basic principle of conservation agriculture is to minimize soil disturbance in order to stabilize the soil structure, increase the fertility and balance the eco-system. Applied together, conservation agriculture practices – no tillage, permanent soil cover, use of crop cover and crop rotation, residue management- have complementary positive outcomes; no tillage maintains soil structure and biological activity; a permanent soil cover protects the soil surface from erosion and creates a stable and favourable micro-climate; cover crops and residue management provides organic matter, reduce soil erosion and improves soil fertility. Management of the soil water balance should be considered as a positive for cover crops and improvement of soil water infiltration, reduction in soil water evaporation, and decreasing water extraction from the soil would impact subsequent plant growth.

Conservation agriculture (CA) refers to a set of agricultural practices involving three basic principles of proven scientific soundness. These include continuous minimum mechanical soil disturbance; permanent organic soil cover with crop residues or cover crops; and diversified, efficient, economically viable, appropriate spatial and temporal crop sequences providing opportunities for saving on inputs (labor, fuel, machinery etc.), improving resource use efficiency (water, nutrient, energy etc.) and mitigating GHGs emission with climate change adaptation. Recently research efforts have been made to refine the crop management technologies which are more resource efficient, improve production and income, and reduce GHGs emission compared to the conventional practices. Resource conserving technologies (RCTs) are increasingly being adopted by farmers in the rice-wheat belt of the Indo-Gangetic Plains because of advantages of saving on labor, water, fuel and cost along with timeliness in operations particularly early planting of wheat.

Introduction

Rice is grown 43.7 m ha land in India. It is cultivated in 39.51 m ha under kharif and 4.26 m ha under rabi season. As a whole, rice production in India was 104.32 m t (2011-12) with an average productivity of around 2.6 t ha-1. Majority of rice grown in India in the eastern part of the country comprises the states of West Bengal, Orissa, Chattisgarh, Assam, Bihar and Jharkhand. Maximum area under rice in eastern India in West Bengal (5.94 m ha) with a production of 15.04 mt. Productivity was maximum in West Bengal followed by Jharkhand, Assam, Bihar, Orissa and Chattisgarh (DOSE, MOA, GOA, 2011). There is a plenty of scope to increase the productivity of these region with proper policies and technological interventions. Rice area in eastern region (23.4 m ha) would be divided in different ecologies, namely, irrigated (23.2%), rainfed upland (17.9%), rainfed lowland (43.1%) and flood prone areas (25.1%).

Conservation agriculture (CA) has benefits to farmers in overcoming labor shortages associated with other tillage practices. With the introduction mechanized CA practices, farmers are able to finalize planting earlier, and can even free the equipment for service hire to neighbors. These CA equipment can reduce the delays in planting and also benefit neighbors who can hire this equipment and be able to plant within the first planting window, commonly associated with better yield gains. Smallholder farmers can also form groups to mobilize resources for equipment purchase to overcome the equipment cost problem. Local production of CA equipment for the smallholder agricultural sector has been almost non-existent prior to 2005.

Increasing consciousness about environmental and coupled health hazards with agrochemical usage in farming and resultant consumers’ preference to safe and chemical-free food are the major factors that lead to the interest in eco-friendly forms of farming in the world. Organic agriculture is one such broad spectrum of production methods in consonance with conservation agriculture that are supportive of the environment and is now practiced in not less than 130 countries to the tune of 30.4 mha in 0.7 million organic farms. In India, about 1.02 mha area is reported to be under organic farming (certified area and area under conversion) with nearly 0.5 lakh certified organic farms. It is believed that adoption of ecologically sustainable farming practices can provide twin benefits of reversing the declining trends in crop productivity and protecting the environment. The demand for organic food is showing an increasing trend with an average growth rate of 20-25% per annum.

Introduction

With the advent of agricultural intensification, soil quality has been the important concern for the scientists, environmentalists and the planners at the global level. Research efforts have been made at the experimental fields, research laboratories and few specific locations, in order to establish the yardsticks, standards and critical values of soil parameters to ascertain the quality of the soil. The primary aim is the management of soil resources as per the need and their rejuvenation through best practices in hand. The idea, as it was aimed at, has now percolated down to the minds of end users-the farmers. The state and Central governments have been sensitized and are attaching great priority to the soil health. In states like Tamil Nadu, Gujarat, Goa, Uttar Pradesh crores of farmers are given “Soil Health Cards”. Central Govt. has the plan to issue these cards to all farmers in the country, detailing the deficiencies in soil and the amount of fertilizer needed.

Introduction

In general economic model, technological change in agriculture is expected to cause the commodity supply curve to shift down and out against a stationary demand curve, giving rise to an increase in quantity produced and consumed, and at a relatively lower price. Agricultural economists have used supply and demand models of commodity markets to represent agricultural research impacts, beginning with Schultz (1953) and Griliches (1958), with important subsequent contributions by Duncan and Tisdell (1971), Akino and Hayami (1975), among others. Such a model is explicitly used in many studies. However, low crop productivity, food insecurity, hunger and malnutrition; inadequate farming knowledge and skills, implements and inputs are characteristic of smallholder agriculture in developing countries including India. Many researchers argue that conservation agriculture can guarantee higher crop productivity, food security, improved net income of the farmers and environmental protection, better than the traditional systems of cultivation practices.

Soil and nutrients are important factors for sustainable crop production in agriculture. Water erosion contributes more than 60% to the area under soil degradation in India. Soil erosion has been a serious threat to sustainable agriculture. However, soil and water conservation measures plays important role in improving the productivity of natural resources. India presently supports 17% of the global population with a geographical area of 329 Mha on merely 2.5% world’s land area and 4% fresh water resources. The net cultivable area in the country is about 140Mha is remaining constant or even squeezing from the pressures of urbanization, industrialization, infrastructure development and to house the ever increasing population. The loss of productive soil is another concern. The loss of fertile top soil by water erosion is estimated to be about 5334 Mt per year with it nearly 8.4 million tonnes (mt) of nutrients was estimated in eroded soil still holds true about in i.e. 2.5 mt nitrogen, 3.3 mt phosphorus and 2.6 mt potassium per hectare is lost due to ill soil and water management practices (Dhruvanarayana and Ram Babu, 1983).

El Nino is the name given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru. When this warming occurs the usual upwelling of cold, nutrient rich deep ocean water is significantly reduced. El Nino normally occurs around Christmas and lasts usually for a few weeks to a few months. Sometimes an extremely warm event can develop that lasts for much longer time periods. In the 1990s, strong El Ninos developed in 1991 and lasted until 1995, and from fall 1997 to spring 1998.

Water is indispensable for our life. About 2/3 of earth is covered with water. No organism can survive without water. So keeping water free from any pollutant is very important. Water is said to be  “polluted” when it is hanged in its quality and composition directly or indirectly by man’s activity so that it becomes less suitable for drinking, domestic, agricultural or any other purpose. Polluted water transmits a large number of diseases in man. They are cholera, typhoid, dysentery, jaundice and other bacterial or viral diseases.  Water becomes polluted by the presence or addition on inorganic or organic substances or biological agents. Soil erosion, leaching of minerals from rocks, decaying of organic matter are natural sources of water pollution. There has been an alarming increase in the degradation of water quality in the recent past in the large cities and industrial areas.

Water pollution can be studied under the following heads—  (i) medium in which it occurs (surface water, ground water); (ii) habitat (lakes, estuaries and open seas); and (iii) type of pollutants (bacterial, metallic, thermal and radioactive).

For the hundreds of thousands of years that we lived on earth,there were few rapid changes in the atmosphere. It is only in recent times, particularly since the Industrial Revolution, that our activities on earth began to modify our environment in a significant manner.  Industrial pollution has affected the water we drink, the air we breathe, and in general,the biosphere itself.Now noise has joined the bandwagon of pollutants.

Noise certainly comes within the scope of definition of a pollutant that “..... any undesirable change in the physical, chemical or biological characteristics of our air, land and water that may or will harmfully affect human life or that of any other desirable species or industrial process, living conditions or cultural assets, or that may or will waste or deteriorate our raw material resources.”

Abstract

The arid Kachchh district, located at the western most part of the Gujarat State in India, is known for its large extent of area under wetland habitat, which is represented by numerous seasonal water bodies and coastal habitats. Vast stretch of grasslands also available in the northern border of the district, the Banni (23⁰ 19’ to 23⁰ 52’ N; 68⁰ 56’ to 70⁰ 32’ E), which encompasses an area of 2,617 km². There are many depressions in Banni, locally known as Dhandh (shallow lakes). During monsoon, rainwater gets collected in these depressions and form shallow lakes. About 34 smaller and bigger size Dhandhs are present in the Banni. Banni communities are highly dependent on the Dhandhs for various purposes. Due to the erratic rainfall in arid Kachchh, Maldharis is highly unstable for livestock in search of fodder and water during drought years. During the normal rainfall years, livestock from neighboring talukas of Kachhh and even from other districts depends on this grassland and Dhandhs. During last decade, the Banni grasslands have seen serious environmental changes due to the invasion of an exotic plant Prosopis juliflora and increasing the salinity are the major issues of Dhandh degradation. Thus, the Banni is gradually losing its capacity to sustain human and livestock population.

Main objectives of the present paper is to examine the local perceptions of wetland and grassland change, socio-economic status, and factors that cause degradation of the wetland and vegetation resources in the Banni grassland.

Abstract

Three seepage tests were carried out for an earth canal at Rawakeeb Research Station (RRS)-west of Omdurman and an average seepage rate of 3.4 m/day was obtained. This value suggests that irrigation canal at RRS should be lined. In addition to that preliminary economic evaluation showed that canal lining is imperative in RRS. A concrete slab form was well designed for lining of RRS canal. Precasting technique and construction technique provided the required water tightness. Economic evaluation was done for RRS canal to investigate the extent of occurrence of supposed advantages, and to estimate costs and benefits and rate of return to lining. The capital expenditure (C), net present worth (NPW) and benefit/cost ratio were found to be 2600.4, 1961.9 and 1.3 respectively which offers a good indicator to adopt the technique.

Since the last decade discussion regarding ecology is being heard. A campaign with a great planning has launched by holding seminar conferences and meets. The ecological problem became a matter of tremendous panic and anxiety. Not only in India but also in entire world this problem is being discussed through all school, colleges and universities on international scale all over world, since it became universal issue now a days. The word ecology was not known to the people 20 years ago, never the less it became familiar even among the villages today. The people in villages are making thorough study of the subject. The experts of ecology from all over the world have been surprised to learn the exhaustive study of the same done by the Indian scholars. We have instituted a separate ministry to look after the environmental problems. The activities injurious to environment are prohibited. An act is there to restrict antienvironmental deeds what made scientists all over the world to take this matter so seriously. Does it mean that the very existence of mankind has been jeopardized by it Let us see what our ancient literature say about the ecology and pollution.

Introduction

Natural Disasters are inevitable, and Indian subcontinent is prone to all type of Natural Disaster either it is flood, drought, cyclone, earthquakes, tsunami or forest fires etc. Disasters can be classified in several ways. A possible sub-division of disaster is: (i) Natural Disasters; (ii) Human made disasters; (iii) Human induced disasters. Another sub-division is related to the main controlling factors leading to a disaster. These may be meteorological, geomorphological/geological, ecological, technological, global environmental and extra terrestrial. Another useful distinction that can be made between disasters is regarding their duration of impact and the time of forewarning. Some disaster strikes within a short period with devastating outcomes; others have a slow onset period with equally or more serious repercussions. According to the available statistics 60% of the total area of Indian subcontinent is venerable to seismic activity of varying intensities, 16% of the country’s total area is drought prone. In India 68% of total sown area of the country is drought prone. Coastal areas of India is exposed to tropical cyclones, tsunami in recent years and among all the disaster occur in the country, River floods are the most frequent and often the most devastating.

Introduction

A disaster is the result of an immediate situation or the result of a long, set process, which disrupts normal human life in its established social, traditional and economic system. This is due to the destruction of environment which is caused by extraordinary natural destructive phenomena or human-induced hazards resulting in human hardship and suffering beyond recovery unless external aid is brought in.

INTRODUCTION

In spite of technological developments for the last few decades, Indian agriculture is still rain dependent. Extreme weather events such as drought in 2002, cold wave during 2002-03, heat wave in the year 2003, increased temperatures during rabi 2003-04 and 2004-05, deficit rainfall in many parts of the country during 2004 and excess rains in 2005 (100cm in Mumbai, floods in MP, Gujarat, Orissa, AP, Tamilnadu and Karnataka) could affect the food grain production considerably. The spatial and temporal changes in important weather parameters such as rainfall, temperature, wind, cloud cover, humidity, etc. would influence crop yields by affecting farmers’ decision in selection of cultivar, use of inputs, crop management practices, etc. These decisions significantly influence the aggregate agricultural output, which , in succession has an impact on the economy of the country as a whole. Thus, the timely and accurate weather based agro -advisories is the need of the hour for sustainable agricultural production.

Further, the quality of utility of agro-advisories can be improved through value addition to the agromet information including forecast and demonstration of economic benefits accrued due to the following of the advisories. Thus making farmers to adapt weather-based advisories for (i) Increasing the quality and quantity of produce, (ii) Efficient utilization of resources, (iii) Minimizing losses due to adverse weather, (iv) Effective utilization of favourable weather events, and (v) Reducing cost of cultivation to enhance profits.

Detailed information on tectonic evolutionary history of the Bay of Bengal is presented followed by elucidation of these characteristics towards tsunamigenesis in this chapter. The Andaman-Nicobar Island Arc (ANIA) is situated on a 1000 km long plate margin and represents a key region in the developing oceanic crustal area of Bay of Bengal. Frequent earthquakes including the tsunamigenic earthquake of 26th December 2004 off the coast of Sunda take place in this region. The subduction of Indian plate under Myanmar-Thailand plate drives formation of chain of Andaman-Nicobar group of Islands. These oceanic crust formation, subduction and arc formation are all seismigenic and generate shallow focus earthquakes in the Bay of Bengal. It is also observed that the seismicity is decreasing as the bathymetry increases towards SW of the Bay of Bengal. Thus, in long term, the slow accumulation of stress as tectonic plates converge may result in many more earthquakes in this region. After a dormancy of over 100 years, the Barren Island volcano renewed its activity following recent earthquakes. The seismic activity along the Andaman-Nicobar trench is continuing with earthquakes of magnitude varying from 4.8 to 7.2 Richter scale. All these observations suggest resurgent and intense tectonic and volcanic activities due to which allied hazards such as tsunami may take place in future.

INTRODUCTION

The evolving Earth, depending on its heat flow pattern in the mantle throughout geological time, had passed through stages, which are diagnosed through characteristic geodynamic signatures. This chapter focuses on a very active region in the crust, namely, the Andaman-Nicobar Island Arc (ANIA) to recognize such signatures and decipher relative safety of surrounding regions including east coast of India. As similar active arc systems such as Sunda Arc & Japan Arc generate volcanic, seismic and tsunami hazards, understanding the ANIA would be of help assess safety of surrounding regions. Abundant geoscientific literature exists on the northern part of the Indian plate, which is undergoing compressive stress since collision between the Indian and Eurasian plates about 55-45my. However, the behavior of remaining part of the Indian plate underneath the Indian Ocean is still sparcely studied. Owing to these reasons, this chapter attempts to fill the gap in our understanding as well as to assess the implications of renewed phases of geohazard occurrences including that of catastrophic earthquake and tsunami of 26^th December 2004.

This chapter introduces the readers about volcanoes and associated features and hazards. Volcanic disasters are like any other geohazards in causing dangerous impacts. However, volcanic explosions are preceded by many surficial expressions that can be detected through satellite imageries, thermal sensors, change in magnetic and gravity anomalies, disappearances of vegetation, sudden appearances of anomalous water vapor, thermal springs and abnormal behavior of animals. Hence, unlike other geohazards, volcanic hazards could be forecast with fairly accurate time limits that may allow evacuation and precautionary safety measures. While avoidance is the best mitigation measure, proper land use planning, provision of scientifically designed damming and diversion methods could save lives and infrastructure from lava flows. Though, atmospheric contamination by volcanic gases, ash cloud and pyroclastic materials could not be thwarted and controlled and thus they could cause havoc.

INTRODUCTION

The term “Volcano” is derived from the name of Roman mythical God of fire “Vulcan”. A volcano is an opening of different shapes, through which, molten rock and gas get ejected either violently or simply flow over earth’s surface. The molten rock and gaseous materials are drawn from deep inside of crust or mantle of the Earth. Repeated ejection of molten materials through vent, fissures or plate margins forms volcanic mountains on earth’s continental or submarine regions.

Volcanism is a threat not only to the lives and infrastructure, but it also drastically alters landscape, impacts atmospheric quality and renders forests, cities and villages and cultivation lands useless. In addition, volcanic eruptions are capable of causing changes in global atmospheric cycles. For example, the eruptions of El Chicho’n in Mexico in 1982, Laki volcano in Iceland and Asama Volcano in Japan in the year 1783 and Krakatau volcano of Japan in the year 1883 have all impacted global climate and atmorpheric dynamics.

This chapter explains how natural disasters are major catastrophic events, which are often aggravated by human intervention, resulting in adverse conditions affecting both natural resources and human habitats. Though drought is as disastrous as any other geohazard, it differs from other geohazards such that it is a ‘creeping phenomenon’, making its onset and end difficult to determine. Only a continuous monitoring of critical parameters ranging from crop failure to joblessness and shifting population, etc, could indicate drought in an area. In this chapter, we demonstrate a GIS based drought forecasting and monitoring model taking Gubbi Taluk of Karnataka as a case study. The approach includes creation of a spatial database of 17 critical parameters and their integration in GIS environment by developing a suitable rating and ranking scheme for the generation of drought severity map. The results have shown that drought could be monitored with the studied parameters and if suitable remedial measures are implemented, their effectiveness could also be monitored with this GIS model.

INTRODUCTION

India is a large country in terms of geographical area, exhibiting greater agro-climatic variation. The country is susceptible to several natural disasters, which are a major constraint to developmental activities. 

reach out their fingers it is gone” - Chinese Philosopher Lao Tzu Tao Te Ching. True to his verses, geohazards are phenomena regulated by the law of natureand it is beyond the human intellect to understand thoroughly and capability to conquer. This is the lesson learnt by us from so many incidences that geohazards cause greatest havoc wherein natural processes are going on and are inhabited by humans. Greed for natural resources and population pressures on the earth’s resources are the causes of many a catastrophic event. Examples in this regard are galore including, damning river courses and location of urban centers along rivers and coasts – flooding, cyclonic storms, tsunami hazards; alteration and deforestation hill slopes for agricultural and construction activities – landslides; unscrupulous utilization of ground water resources – drought, etc. This chapter is an attempt to draw the attention of human communityasa whole toturn towards learning to live with the nature without alterning the natural processes to get rid of impacts of geohazards as a best ever mitigation measure. In other words, this chapter attempts to emphasize the need to change our attitude to escape from natural hazards instead of attempting to tinker around natural processes only to get battered at the end.

INTRODUCTION

Oxford English dictionary states that the word ‘disaster’ is derived from the 16^th century French word ‘disastre’, which is a combination of two terms namely, ‘Des’ meaning bad or evil and ‘astre’ means star. Thus “desastre” signifies a ‘bad star’ or ‘evil star’. Disaster, therefore, implies loss or damage occurring due to some unfavorable star. However, in terms of modern knowledge, the word ‘disaster’ denotes any odd event, whether natural or man made, which can bring about sudden and great miseries to humanity in the form of loss of life or/ and property.

7.1 Introduction

The earth's crust is made up of igneous, sedimentary and metamorphic rocks. Each variety of rocks exhibit some columnar joints in Igneous rock, characteristic structures like bedding in sedimentary rocks and fabrics like schistosity and gneissosity in metamorphic rocks.

As a result of tectonic activities in nature, rocks may suffer deformation, rupture, dislocation of beds (Fault) or other planar structures.. The whole study of such deformation is known as structural Geology. It has been observed that sedimentary rocks are most suitable for studying structures, because these rocks are deposited in quiet environment, and initially the beds arranged in horizontal position. As a result of stress due to kinematic movements/tectonism, the horizontal beds tend to deviate from their horizontal disposition to dipping position or get folded or faulted. Thus the rock develops various kinds of structures. There are following structures present in sedimentary rocks:

Abstract

Visualisation of geological process raises special issues for scientists and animators. The degree of physical movement of a rising arch or along a fault line may be very small compared to the normal terrain variation. Over a long time period the major changes in the environment may come from the more substantial surface manifestations of changing draining regimes. In Tamil Nadu State in South-Eastern India there are continuing tectonic movements arising from the collision of the subcontinent with the greater Asian land mass. Over comparatively recent times (7000 years) these movements have had a major impact on drainage and other hydrological outcomes. The Cauvery River in particular has migrated several hundred kilometers over this period. A mosaic was made from recent satellite imagery and then manipulated to create surface textures for dates between -7000 years and +1000 years. Changes in the terrain surface, such as rising arch structures and descending grabens, have been modelled and animated. The combination of terrain movement and surface change provides a visual history of the period.

Introduction

The continued northward movement (5±6 mm per year) of the subcontinental land mass of India induces substantial tectonic pressures all over India. In the southeast, primarily within Tamil Nadu, there is significant differential movement, both vertical and horizontal, of portions of the existing land mass. This is producing a number of effects:

Abstract

Indian Peninsular shield has been thought as tectonically inert and aseismic for many years by the Geoscientists. But, subsequent to the disastrous earthquakes in Killari, Jabalpur and Kutch, studies have been initiated in multiple directions on various aspects of seismicities. The present study is aimed at bringing out a possible picture on the seismic vulnerability of parts of Westernghats of Tamil Nadu using various tectano geomorphic anomalies like unifrequency lineaments and different levels of dissection of plateaus, denudational geomorphic anomalies like anomalous talus materials and fluvial geomorphic anomalies like radial drainages, compressed meanders, eyed drainages and wider flood plains interpreted from the raw and digitally processed Landsat TM and IRS P6 LISS-III satellite datasets. The subsequent generation of individual GIS layers on these anomalies and their integration revealed that the N-S faults are tectonically active and the NE-SW and NNE-SSW faults are active faults. Many earthquake epicenters were also found to fall along these lineaments / faults.

Introduction

The Indian peninsular shield, exposing the Archaeozoie - Proterozoic piles of rocks, is known for its tectonic inertness and the related land stability. Owing to such shield area character, the geoscientists were also having strong convictions for a long time that seismically the area is safe.

Abstract

Geological conditions in the Tertiary mountainous areas of the western and eastern hill ranges of Manipur often cause landslide movements. These repeatedly occur mostly in old landslide regions during rainy seasons on a large scale, causing considerable economic loss and injuries and deaths of humans. In order to improve such landslide hazard assessment of the region for effective mitigation, Electrical resistivity surveys were conducted using Schlumberger array technique on the very unstable and problematic frontal part of the Kotland landslide, NH-37, Manipur along three profiles. Electrical resistivities aided the characterization and quantification of the subsurface rock units, structure and tectonic conditions of the Landslided area which can contribute for the better planning of mitigation strategies. The results lead to the elucidation of depth of the different litho-units and the geometry of failure surface. The probable failure surface was observed between 10 and 22m depth, characterised by low resistivity (< 150 Ωm) and geometry of the sliding surface was rotational. In addition, a fault was also inferred in the resistivity pseudosection model and hence the area may be highly vulnerable to landslides.

Abstract

The Nilgiri Mountains of South India is one of the Landslide prone hill ranges in India. The landslides, in general, are due to the independent, interdependent and the combined effects of natural earth system processes, triggering phenomenon and anthropogenic activities. So the scientists, technocrats and the academicians from all over the world have started studying the landslides using various techniques and advanced tools in mapping the morphology, preparing the vulnerability maps and carve out mitigation strategies. But the discrimination of active slides is a difficult task and also needs continuous monitoring and further a time consuming process too. So, in this context, an attempt has been made to study the signatures of active sliding in one of old slides namely the “LINGASLIDE” in which frequent minor sliding events are often reported. In the study, Total station based large scale topographic survey was carried out in LINGASLIDE and from the same 50 cm topographic contours were generated. From such large scale contours, Digital elevation Model (DEM) was generated and from the DEM, shaded relief map was generated.Uutilizing both the contours and shaded relief maps, small slides were mapped in the LINGASLIDE from the well exhibited subsidiary crowns, toes and the traverse cracks. Resistivity tomography surveys were also carried out along two longitudinal profiles and one traverse profile to identify the subsurface geology, the slip surface and the zones of moisture accumulations, if any. The subsidiary crowns, toes, the conjugate fracture systems and the resistivity tomography showed that the LINGASLIDE is active and the sliding is going on towards easterly because of the easterly compression,resulted from the higher slopes caused by the settlements raised over Lingaslide and the obstruction provided by the retaining walls at the toes in the east. Such compressive forces are clear from the NW-SE and NE-SW fractures seen in Lingaslide and the sliding is clear from the cracks seen and monitored in the buildings constructed over Lingaslide.

ABSTRACT

The multi-sensor airborne geophysical survey was carried out over Nalgonda district, Andhra Pradesh, during the field season 2002-03, with an objective to locate potential areas for mineral exploration. The area comprises older metamorphic rocks of Peninsular Gneissic Complex of Archaeanage represented by gneisses, granite, amphibolite and banded magnetite quartzite. Leucocratic intrusive granite, extending over a length of about 40 km around Suryapet in NNW-SSE direction exhibits intense fracturing. Two sets of vertical to sub-vertical fractures have been noted in granite. Yellow stains observed in granite near fracture planes reveal the presence of secondary radioactive mineral encrustation. The ground magnetic and spectrometric observations indicated that the uranium mineralization is confined to these fractures in granite. Petrographic, ore-microscopic and scanning electron microscopic studies revealed evidences of metamict alteration surrounding monazite/apatite inclusions within biotite, and magnetite grains in granite. These studies also indicated evidences of discrete grains of uraninite / coffenite / pitchblende (containing Thand Ce). Chemical analysis of the rock samples (by NAA) collected from anomalous zone reveal high uranium concentration of the order of 1200 ppm, marked by high values of total Rare Earth Element concentration (800 ppm).

The leucogranites are characterized by high LREE and a negative Eu anomaly suggesting plagioclase fractionation. An ultramafic enclave near village Kutubsahipur shows highest concentration of both uranium (1240 ppm) and REE (890 ppm) analyzed by BARC and NAA Lab, GSI.

ABSTRACT

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

ABSTRACT

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

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

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

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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

Abstract

The damages caused by the tsunami surge of 26, December 2004 could not be recuperated. There is no second opinion for the above statement as attested by the consequences of tsunami surge on the coastal landforms, human lives, properties, biological assets, etc., The attempt made to evaluate the damages caused by the tsunami surge along the study area divulges various factors regarding the response of the coastal environment to this weird phenomenon. Kanyakumari district witnessed the tidal inundation of 50 – 450 m, the least along Colachel and the maximum in Kanyakumari and Muttom coasts. Run-up elevations were seen even up to 6 m in Manakudi and Colachel coasts. In major parts, the beaches of the study area had endured lofty erosion of beach sediments. High occurrence of Casualty was reported in the Coasts of Colachel, Kotilpadu, Manakudi and Azhikkal. Similarly, loss of man-made structures were also observed to be high along the Coast of Manakudi, Colachel, Kotilpadu, Azhikkal and Muttom. Costly articles like boats, fishing nets, etc., were also damaged in Kanyakumari, Pallam, Muttom, Kadiapatanam, Kesavanputhenthurai and Colachel. The quality of water has also been found to be affected with high level of pH and TDS in the coasts of Manakudi and Colachel. Such Colossal damages in the area is attributed to its geo-position exactly at the receiving point of the diverted tsunami surge by Sri Lanka. Bathymetry also seems to have played a crucial role in determining the intensity and angle of the seismic wave propagation in the area.

Keywords: Tsunami, India, Damages in Kanyakumari, Evaluation, Map, GIS.

Abstract

The Car Nicobar Island is one of the several islands in Indian Ocean which was severally damaged by the Great tsunami on 26 December 2004. The great tsunami event caused massive devastation, in the form of loss of life and property in south and south East Asia. The objectives of the study are to assess the changes in the coastal features of the Car Nicobar Island using various indicators such as the tsunami height, run- up elevation, water flow direction, erosion, sand deposition and coastal subsidence. Andaman &Nicobar Islands are the summit of the submarine mountain range lying along the great tectonic suture zone extending from Eastern Himalaya to Sumatra and Lesser Sunda via Myanmar border and Arakan hills. The IRS P-6 satellite data has been found to be very useful in the present tsunami assessment studies. The digital analysis of the satellite data was done using the image processing software (ERDAS IMAGINE 8.4) and DTM to quantify the tsunami height (15 m), run up elevation (2-19 m), inundation (295-1203 m) and coastal responses. The settlements and coconut plantations have been severely damaged in the island, which were assessed using GIS analysis of the pre and post-tsunami satellite data.

Keywords: Tsunami, Wave Height, Run-up Elevation, Inundation, Coastal Responses, Remote Sensing, GIS.