eChapters

Abstract

The recent tsunami occurred on 26^thDecember 2004, caused great devastation along the east coast of Tamil Nadu, India. As the said tsunami has caused colossal damages, the impact assessment has become essential for tsunami mitigation measures. In this context, the extent of tsunami inundation, loss of lives, property loss and damages to physical and natural resources have been assessed in the tsunami affected area between Ennore and Mahabalipuram along the east coast of Tamil Nadu.

IRS LISS III PAN merged satellite data and IKONOS data were used for mapping the pre-tsunami geomorphology and land cover conditions and IRS-P6 PAN merged satellite data were used to map the post – tsunami terrain conditions including the inundations. From the study it is inferred that wherever buildings and population are denser the loss is more. Hence, vertical expansion may be needed as an alternative or to supplement horizontal expansion. Bio-shield along coastal areas, involving raising of mangrove forests, planting of casurina, salicornia, palms, bamboo and other tree species and halophytes which can grow near the sea will serve as speed-breakers for the up rising waves.

Keywords: Tsunami, Damage Assessment, Mitigation Measures, Chennai region.

Introduction

On 26^th December 2004, the Indian coastline experienced the most devastating tsunami in recorded history. The tsunami was triggered by an earthquake of magnitude Mw 9.3 at 3.316ºN, 95.854°E off the coast of Sumatra in the Indonesian Archipelago at 06:29 hrs making it the most powerful in the world in the last 40 years. In recent years increasing the vulnerability to natural disasters of developing countries is a major reason for concern. The potential loss of human lives and property due to natural hazards is very high in the urban areas of these countries. The Information obtained from conventional tsunami hazard maps does not always provide sufficient data for users .needs. The difficulty in presenting more significant information on tsunami hazard maps in conventional paper format is due to the limited available physical space of that format. Printing more information on such paper maps tends to confuse rather than provide more needed information to users. Furthermore, these kinds of maps provide little opportunity for users to ask for additional information, to determine the relationships between different kinds of information and important quantitative analyses. Furthermore, Tsunami hazards have important temporal attributes. Presenting these attributes on the map; e.g. the sequence of volcanic eruptions in a region or the frequency of tsumani in a particular area during a particular period of time is very difficult.

Abstract

Ennore is an industrial region having many industries on chemicals, fertilizers, refineries etc., discharging their effluents into the Buckingham canal. Present study focuses on the impact of tsunami on water quality of Buckingham Canal segment found to the north of Chennai city, Tamil Nadu, India, in addition to the human interferences. Water samples were collected from surface and near bottom at five locations covering about 20km stretch of the Buckingham Canal during high tide on the spring tide day before (December 2004) and after (January 2005) the mega tsunami. Various water quality parameters measured were pH, Temperature, Salinity, Dissolved Oxygen, Suspended Particulate Matter, Nutrients and Chlorophyll. The maximum depth observed in the canal was 2.5m in December, whereas a shallow depth of less than 0.5m was recorded in January. The water quality analyses confirmed the incursion of saline water (upto 32ppt) into the Canal. Not much variations were observed in Dissolved Oxygen and pH. Because of the organic pollution in the canal, the water was rich in nutrients before tsunami, whereas due to the large quantity of seawater invasion, dilution had occurred after tsunami. High turbidity was observed in January 2005 indicating the tsunami induced disturbance and resuspension of the sediments from sea bed.

Keywords: Tsunami, Ennore, Tamil Nadu, Buckingham Canal.

15.1 Introduction

A tsunami is a series of waves created when a body of water, such as an ocean, is rapidly displaced. Earthquakes, mass movements above or below water, volcanic eruptions and other underwater explosions, landslides, large meteorite impacts and testing with nuclear weapons at sea all have the potential to generate a tsunami. The effects of a tsunami can range from unnoticeable to devastating. The term tsunami comes from the Japanese words meaning harbor (“tsu”,) and wave (“nami”,). The term is created by fishermen who returned to port to find the area surrounding their harbor devastated, although they had not been aware of any wave in the open water. Tsunamis are common throughout Japanese history; approximately 195 events in Japan have been recorded.

A tsunami has a much smaller amplitude 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 (Fig. 15.1). Tsunami have been historically referred to as tidal waves because as 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 (Iwan, W.D., 2006).

Abstract

During natural disasters, mostly panic and curiosity lead to greater causalities. But the tsunami is such a disaster which no one have witnessed during their life time nor heard of from their ancestors. On 26, December 2004, tsunami has struck all of a sudden many South Asian coasts including the east coast of Tamil Nadu and Andhra Pradesh causing greater devastation and causalities. This historical event has taught us many lessons and the paper deals with some aspects related to tsunami from the citizen’s view point.

Keywords: Natural calamities, Tsunami mechanisms, Mitigation strategies, Citizen’s perspective.

INTRODUCTION

The tsunami that ravaged the coasts of South India had left tell tale signs that affirm the need for early warning systems as well as well-planned mitigation measures for the benefit of the affected. Over the last 12 months, since the tsunami struck the east coast of India on 26 Dec. 2004, numerous seminars, discussions, programmes and project proposals have been deliberated on various aspects that deserve attention. Government agencies, self-help groups and non-governmental organizations (NGOs) have done commendable post-tsunami work. All sections of the society have responded both emotionally and rationally to the event in an unprecedented manner. In retrospect, to the informed citizen – one who has heard about the event, read about it and discussed it with others, though not have had the ‘experience’ of the natural disaster by himself / herself - what do all these mean ? the tragedy and its aftermath. This paper documents the issues that a citizen would like to ponder over so as to understand the various dimensions of the post-tsunami activities and draw a few lessons that the tragedy had taught us. The major issues pertain to (i) the mechanisms (ii) the coastal vulnerability and the need for assessment (iii) mitigation strategies (iv) media exposition (v) communication networking and (vi) educational facilitation.

The phenomenon we call tsunami is a series of large waves of extremely long wavelength and period usually generated by a violent, impulsive undersea disturbance or activity near the coast or in the ocean. A tsunami is a very long-wavelength wave of water that is generated by sudden displacement of the seafloor or disruption of any body of standing water.  Tsunami are sometimes called “seismic sea waves”, although, as we will see, they can be generated by mechanisms other than earthquakes.  Tsunami have also been called “tidal waves”, but this term should not be used because they are not in any way related to the tides of the Earth.  Because tsunami occur suddenly, often without warning, they are extremely dangerous to coastal communities.

Introduction

Indian arid zone is one of the largest subtropical deserts of the world of which 20% is arid and rest is semi-arid. Hot arid zone is spread over 31.7 million ha area and mainly confined in the states of Rajasthan, Gujarat, Andhra Pradesh, Punjab and Haryana. The major part of hot arid region of the country lies in western Rajasthan (19.62 mha) followed by North-western Gujarat (2.16 mha). It is characterized by high aridity index, extremes of temperature low and variable precipitation, very high wind velocity and dust storm, high soil pH, high infiltration rate, very limited availability of groundwater and saline ground irrigation water (More, 2010). Under such harsh climatic conditions cultivation of vegetable crops in open condition results in very low and poor-quality yield which fetches less return per unit area. By creating the suitable micro-climate for plant growth round the year cultivation of vegetables can be done under adverse climatic conditions. It is possible through protected cultivation which has tremendous scope in peri-urban areas of the country (Singh and Sirohi, 2004). It is the best way to increase the productivity and quality of vegetables, especially cucurbits. India is the second largest producer of vegetables in the world next only to China. Presently India has 178.17 million tonnes of total vegetable production, but the productivity and quality of most of the vegetable crops is very poor (17.40 t/ ha) due to several biotic and abiotic stresses due to open field cultivation. In Rajasthan, the total production of vegetables is very less i.e. only 1.81 million tonnes from an area of 0.17 m ha with a productivity of 10.66 t/ ha.

The decreased ability of water to transmit light which is caused by suspended particulate matter ranging in size from colloidal to coarse dispersions is refers as turbidity.
Principle
Turbidity is measured by its effect on the transmission of light, which is termed as Turbidimetry or by its effect on the scattering of light, which is termed as Nephelometry. Turbidimeter can be used for sample with moderate turbidity and Nephelometer for samples with low Turbidity. Higher the intensity of scattered light higher the turbidity.
1 mg SiO2/L = 1 unit of turbidity

In this chapter, an attempt is made to emphasize the fact that while no country in the World is safe from geohazards, a proper understanding on their causes, ways to mitigate them and surviving techniques would help reduce the life and property loss. Each geohazard has its own characteristic way of potential impact and hence classifying vulnerability of different regions and creating awareness on potential impact is essential. In addition to providing basic information on geohazards, this chapter presents a conceptual model on hazard mitigation, rescue and relief operations.

INTRODUCTION

Every year, thousands of people are killed by volcanic eruptions, earthquakes, landslides and floods. These natural causes damage human settlements and infrastructures (GOI, 2004) inflicting life and economic loss. As human population increases, habitation on hazardous and or vulnerable land becomes more common and the risks posed by these hazards increase. The need to observe their behavior, understand them better and mitigate their effects become ever more urgent (IGOS, 2003). Decades of research may have contributed towards betterment of our understanding on the processes of geohazard formation but still a long way has to be covered to develop better mitigation procedures.

Abstract

The UAE Space Reconnaissance Center (SRC) is accounted as a major national and regional source of up-to-date geospatial data, with direct reception of IKONOS, IRS and KOMPSAT satellite imagery as well as access to some other satellite and aerial imagery resources; an activity which covers the whole Middle East region. The main concern in monitoring the environment of UAE and surrounding countries is the desertification process, the monitoring of which requires careful watching of the sand movement and some other relevant features.

This paper throws light on the role of various types of satellite images in monitoring desertification, by utilization of IKONOS, IRS Pan and Landsat TM images covering part of Liwa and Alain areas, representing the two main dune regimes; Liwa and Manadir, which constitutes the northeastern edge of the Empty Quarter sand sea.

The availability of high resolution images makes it possible to detect the yearly or even seasonal sand movements, being controlled by the prevailing wind conditions and distance from the main sand source. The results clarify that movements of up to 25m was encountered at some small sand dunes and about 10m for larger sand dunes, towards the SSE and SSW in Liwa area. In Rimah area a movement of up to 30m was noticed at a small sand dune towards the ENE and about 12m shift in the hinge of a larger sand dune towards the NW. Temporary or permanent ? movement of thin sand sheets can reach 100’s of meters, was easily detected on Landsat images; ~ 25km NE of Alain city. The 5m panchromatic images, on the other hand, helped in tracing sand movements measured in few 10’s of meters, and interpretability of such images was enhanced by merging them with Landsat imagery.

Abstract

Dissolved Organic Carbon (DOC) consisting of water soluble organic molecules and by products of organic decomposition and chemical degradation processes, constitutes a critical link in carbon and nutrient cycles. The quality, or chemical and physical character, of DOC affects the degree to which it is transformed by biological and chemical processes. The significance of DOC was studied in layered coastal aquifers of the Pondicherry region during four different seasons. Pondicherry region has varied geological set up ranging from Cretaceous to Recent formations. A total of 52 groundwater samples were collected from various aquifers like Alluvium, Tertiary(Upper Cuddalore, Lower Cuddalore) and Cretaceous for two different seasons of pre- monsoon(PRM), and post-monsoon (POM). The samples were analyzed for major ions and DOC. The range of DOC in the study area is 0-14 mg/l. Very high DOC concentrations were measured during PRM in the samples from Alluvium and Lower Cuddalore Formation. The samples of these formations were compared with pH, Ionic strength, log pCO₂ and carbonate minerals concentration. The alluvial aquifer shows that pH governed dissolution along the coastal tracts and in Upper Cuddalore formation it’s based on interaction between aquifer matrix and groundwater.

Abstract

A study on colloids in groundwater and its relationship with the geochemical parameters is reasonably essential because of its facilitating nature to transport radionuclides in groundwater. Colloid sampling has been carried out in the coastal aquifers of southeast coast of India. Two different bore wells were selected based on the distance from the coast to collect groundwater samples. On the basis of the result achieved from this study, a reliable representation is emerging. The values of pH and EC are governed by the different size fraction of colloids. In this study, the relation between different size fractions of groundwater colloids and its pH, TDS and EC were carried out. These parameters were analyzed in the lab and its influence with four fractions of colloid like 1.2, 0.8, 0.45 and 0.22 µm have been discovered by smooth scatter plot. The accumulation of particles weighting by normal weighing instrument. There is an higher accumulation of particles found in Kalpakkam than Anupuram in all the size fractions. For separation of particles high frequency pressure was used by ultrasonic cleaner had been carried out. This method is very simple and more reasonable than any other methods.

Abstract

The development and management of fresh groundwater resources in coastal aquifers are seriously constrained by the impact of seawater intrusion. The coastal aquifers are fragile and this situation becomes more intense like that of the coastal Cuddalore region. The geochemical signature of groundwater of Cuddalore coast was studied for Pre Monsoon, Southwest, North east and Post Monsoon seasons by collecting total of 64 groundwater samples in each season. The collected samples from were analysed for physical parameters, such as electrical conductivity (EC), pH and major ion concentrations, such as Ca, Mg, Na, K, Cl, HCO₃, PO₄ and SO₄. Interpretation of analytical data shows the predominance of  Na–Cl type   in PRM and Ca- Mg-Cl type  is the dominant facies during POM. The Chaddas evaluation diagram shows that the hydrogeochemical evaluation plot for PRM samples fall in  Na-Cl type. The ratios of Na/Cl and Cl/HCO₃ is also enumerated the fact that the most of the samples from PRM and few samples from other seasons also indicates dominance of salt water intrusion.

Rainfall in India, is a phenomenon that is not just a meteorological event but the very lifeline of the subcontinent, profoundly shaping its landscapes, agriculture, and, most importantly for our study, its diverse aquatic ecosystems and the fisheries they support. India experiences a unique and dominant rainfall regime driven primarily by the monsoon, a seasonal reversal of wind patterns. The arrival, intensity, duration, and spatial distribution of this rainfall have farreaching consequences for the availability of freshwater, the health of rivers, lakes, and wetlands, and the productivity of coastal and marine environments. For aspiring fisheries professionals in India, a thorough understanding of the patterns and vagaries of Indian rainfall is indispensable.
Consider the sheer diversity of aquatic habitats across India, from the snowfed rivers of the Himalayas to the monsoonal wetlands of the Gangetic plains, the brackish backwaters of Kerala, and the vast coastline. The characteristics and productivity of each of these systems are intricately linked to the patterns of rainfall they receive. The monsoon replenishes rivers and groundwater, sustains agricultural practices that can impact water quality, influences the nutrient flow into coastal waters, and can even trigger crucial life cycle events for many aquatic species (Fig. 7.1).

Unsupervised classification is the technique of classification of raster data in which no prior information is provided by the user. Raster data is classified based on their spectral characteristics such that the pixels having similar spectral properties in the multispectral feature space are grouped together in one class. Unsupervised classification is mainly performed by clustering algorithms. The purpose of these algorithms is to minimize within cluster variability and maximize between clusters variability. The user must interpret and label the classes after performing unsupervised classification. This method of classification requires minimum data which makes it easy and quick, but user has toput efforts in identification of the classes. This method could be useful when user doesn’t have any prior knowledge about the study area. This method removes subjectivity and enables us to get the unique classes which might be unrecognized by the user. K-means is the most commonly used method for performing unsupervised classification. In this chapter, we have discussed K- means, CLARA and unsupervised random forest method for classification of raster data in R.

Vegetable crops stand as pillars of global food security and human health, providing essential vitamins, minerals, and dietary fiber crucial for well-being. Their diverse forms, flavors, and nutritional profiles contribute significantly to balanced diets worldwide. However, the successful cultivation of these vital crops is intricately linked to the surrounding atmospheric environment. This
book, “Agroclimatology of Vegetable Crops: Classification and Cultivation” endeavors to explore and elucidate this critical relationship, providing a comprehensive understanding of how climate and weather influence the growth, development, yield, and quality of a wide array of vegetable crops. The interaction between vegetables and their climate is a dynamic and multifaceted one. From the moment a seed germinates to the final harvest, every stage of a vegetable plant’s lifecycle is profoundly impacted by factors such as temperature, precipitation, solar radiation, humidity, and wind. Understanding these influences is no longer merely academic; in an era marked by increasing climate variability and the urgent need for sustainable agricultural practices, it has become a fundamental necessity for ensuring consistent and reliable vegetable production (Fig. 1.1).
Within these pages, readers will find detailed analyses of
• Fundamental Climatic Parameters and Their Impact: A thorough examination of how temperature regimes, rainfall patterns, solar radiation intensity and duration, humidity levels, and wind patterns affect key physiological processes in vegetable plants, such as photosynthesis, respiration, transpiration, and nutrient uptake.

This book, “Meteorology and Geography” is designed to equip aspiring fisheries professionals with a foundational understanding of the atmospheric and terrestrial processes that profoundly influence aquatic ecosystems and, consequently, the distribution, abundance, and health of fish and other commercially important species. For too long, the study of fisheries has sometimes been perceived as largely focused on the biology and ecology within the water itself. While these aspects are undeniably vital, the reality is that aquatic environments are not isolated entities. They are inextricably linked to the atmosphere above and the land surrounding them. The weather patterns we experience daily – from sunshine and rainfall to storms and temperature fluctuations – directly impact the physical and chemical characteristics of our oceans, lakes, and rivers. Similarly, the geographical landscape, including topography, soil composition, and coastal features, plays a critical role in shaping these aquatic habitats. Consider for a moment the seemingly simple act of rain. Rainfall over land influences river discharge, bringing nutrients and sediments into freshwater and coastal systems. Changes in salinity, turbidity, and nutrient levels can dramatically alter the suitability of these waters for different fish species. Strong winds can drive ocean currents, upwelling events that bring nutrientrich deep waters to the surface, and the dispersal of fish larvae. Extreme weather events like cyclones and floods can cause devastating impacts on both wild and aquaculture-based fisheries. Furthermore, the broader geographical context dictates the regional climate, influencing long-term patterns of water temperature, precipitation, and wind. These climatic conditions, in turn, determine the types of aquatic ecosystems that can thrive in a particular area and the species that inhabit them.5 Understanding these geographical controls is essential for predicting the potential and limitations of fisheries in different regions.

Nanotechnology has emerged as a revolutionary force in the food industry, providing innovative solutions to improve food quality, safety, and usefulness. Researchers have devised novel ways to numerous issues in food production and preservation by harnessing nanoparticles' unique traits, such as their high surface area-to-volume ratio and customizable physicochemical characteristics. Nanotechnology-enabled food additives provide a wide range of benefits, including improved texture, taste, color, and nutritional value, as well as increased shelf life and microbiological safety. Furthermore, nanoparticles are effective transporters for bioactive chemicals, allowing for targeted and regulated release within the food matrix.

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.

The relentless march of urbanization, coupled with the growing uncertainties of a changing climate, casts a long shadow over the water security of our cities. Unlike their rural counterparts, urban areas face a distinct and often amplified set of challenges when drought strikes. The intricate web of municipal water supply, the concentrated demands of industry and commerce, and the sheer density of population render urban centers particularly vulnerable to the cascading impacts of water scarcity. When the taps run dry or restrictions tighten, the repercussions extend far beyond parched lawns and wilted gardens, impacting public health, economic stability, and the very fabric of urban life This chapter serves as an entry point into the critical field of urban drought management. We will delve into the unique characteristics that distinguish urban droughts from their rural counterparts, highlighting the interconnectedness of water systems and the amplified socioeconomic consequences within city limits. We will explore the increasing frequency and intensity of these events, driven by both natural climate variability and