eChapters

8.1 Introduction

The knowledge of statistics and probability is very helpful for correct prediction of hydrological data and correct prediction of hydrological data is useful in giving good performance in all water resources projects. Since hydrological data are highly stochastic varying both in space and time, it is essential to predict them as correct as possible. The hydrologic evens do not depend on physical and chemical laws but depend entirely on nature. They cannot be predicted exactly by using any relationship but can be predicted at different probability levels by fitting suitable probability distribution functions. Application of statistics and probability in the field of hydrology can help to predict the hydrologic events in a better way. In hydrology, objectives of statistics are as follows (Suresh, 2008):

Data mining is a powerful technology which helps in extracting future trends and behaviour from large databases. Thereby it helps decision makers to make knowledge-driven decisions. One common form of real-world data is time series. The suitable models are required to analyze time series data. This chapter provides a short introduction to stochastic system, uncertainty, basic statistics time series analysis and some stochastic models.

6.1 Introduction

Stratigraphy is the branch of geology which deals with the study of rock layers (strata) and layering (stratification) in their chronological order. It is primarily used in the study of sedimentary and layered volcanic rocks in order to interpret geological history and age. The term historical geology is also used as a synonym of stratigraphy but in a wider sense, it deals with the whole sequence of events that make up the history of the earth from its origin and age relations of rock strata, evolution through its life form, and structures. The scope of stratigraphy is very wide; it involves description and classification of layered sedimentary rocks and also of igneous & metamorphic rocks. The study involves correlation between different areas like lithological characters, fossil content, geophysical and geochemical properties including absolute radiometric dating.

6.2 Principles of Stratigraphy

Stratigraphy is based on the following few principles:

6.2.1 Law of superposition

In a sequence of horizontal sedimentary rock layers, the younger layers are on the top and the older layers are at the bottom. To put it another way, in a normal sequence, each bed is younger than the bed beneath it. Geologists today use it as the basis for a bed-by-bed analysis of geological history in a given area. This is important to stratigraphic dating, which assumes that an object cannot be older than the materials of which it is composed. This law known as "Law of Superposition" was first proposed by the scientist Nicolas Steno in the 17th century.

5.1 Introduction

A steam can be defined as a flow channel in to which the surface runoff flowing over the land surfaces and base flow/ground flow flowing below the ground surfaces meet. It receives the total flow from a specified basin. Streamflow representing the runoff phase of the hydrologic cycle is the most important basic data for hydrologic studies. Interestingly, stream flow is the only part of the hydrologic cycle that can be measured accurately. Stream flow is a historical data and like rainfall and runoff, it is a stochastic hydrologic variable. It is also called as discharge or rate of flow. Discharge is defined as the volume of water flowing through a cross section in a unit time.

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:

27. STRIKE AND DIP

Outcrop : A part of the rock formation which crops out or exposed on the surface of the earth is called an outcrop.

The total area over which a particular rock unit occurs at the surface whether visibly exposed or not. The term outcrop is especially used for delination of such an area on a geological map.

Attitude : To study these outcrops their attitude help in better understanding the position of the bed on the ground surface or in field is attitude of a bed can be described with the help of two basic structural elements i.e. strike and dip.

Introduction

Environmental problems have come to the forefront as one of the most important issues in transport policy. For a number of pollutants the road transport sector is one of the most significant contributors to environmental pollution. Vehicular emissions have been identified as one of the major contributors in deteriorating air quality in the urban centers. The problem has further been compounded by the concentration of large number of vehicles and comparatively high motor vehicle/population ratios in these cities. Substantial SPM, RSPM CO₂ and No_x are emitted. The problem of air pollution has assumed serious proportion in some of the major metropolitan cities of India. Therefore, CPCB has 296 monitoring stations all over India covering major cities.

The air pollution situation in most of the cities is still far from satisfactory. In India the major air pollution reason is automotive smoke and smoke from industries. New channels are also publishing pollution levels in selected metropolitan cities. The most polluted city in Asia is Pune. The SPM and RSPM levels are displayed at various squares to create awareness among the masses.

Smaller cities like Nanded, Parbhani and Yavatmal are not covered under National Ambient Air Quality Monitoring (NAAQM) scheme of Central Pollution Control Board (CPCB). The National Ambient Air Quality Standards for suspended particulate matters (SPM) are based on gravimetric measurement. Standards for Respirable suspended particulate matters (RSPM) are also based on gravimetric measurement. The development in terms of number of vehicles and building construction has also reached at the doors of these cities and towns. Nanded city having population of 5.5 lakhs has total number of Auto rickshaws more than 5,000. In the present study, Nanded city has been selected to check particulate matters and gaseous pollutants. Since, the city is one of the important Pilgrimage and commercial centre.

ABSTRACT

Trace Elements were analysed from water samples collected from bore wells from block 2, 5, 14, 26 and 29 at Neyveli Township. Lead Concentration has crossed the limit of ISI standard prescribed for drinking which is 0.100 ppm. Lead concentration in the order of 0.082 ppm at block 5 and 0.11 ppm in block 29 were observed. Cadmium concentration has also crossed the limit of ISI (0.010 ppm) for drinking purpose, which is 0.02 ppm in block 26. Chromium concentration has also crossed the permissible limit of ISI standards (0.05 ppm) for drinking, which is 0.098 ppm in Block 14.

The above elements when compared with ISI standards for drinking water have shown a slight increase in concentration of lead, cadmium & chromium. Concentration of lead in Neyveli basin may be attributed to basement geochemical sources influenced by physical and chemical weathering. High concentration of chromium and cadmium in the aquifer may be due to anthropogenic activity probably from effluents of closed briqueting & carbonization plant, which is due south of block 14.

Abstract

Conventional wisdom holds that variability in rainfall represents a significant variability of agriculture production. But urbanization of the cities on one hand and climate change on theother hand areaffecting the agriculture. Surprisingly, there have been very few analyses exploring the link between rainfall variability and urbanization on agriculture production. Therefore an attempt is made in this paper to know the affect of rainfall variability and urbanisation on the cropping area. For this purposeNDVI analysis is carried out in the catchments of Osmansagar and Himayathsagar Reservoirs by using the medium to high spatial resolution multi spectral data provided by remote sensing satellites, such as Landsat TM, IRS-1C/1D LISS-III and IRS-P6 LISS-III has been used for the years1989, 1994, 1998, 2002 and 2008 for Kharif season, 1975, 1990, 1994, 1998, 2003 and 2008 for rabi season which is collected from NRSC (National Remote Sensing Centre). From this analysis it is found that the increment is more in rabi season compared to kharif season due to the increment of non-monsoon rainfall intensities and ground water withdrawal structures. The increased utilization of the groundwater is causing the reduction of inflows to the reservoirs in the recent years because whatever the rainfall that occurs in the catchment, first utilised for meeting the depleted soil moisture and ground water consequently reducing the surface runoff.

Keywords : Climate change, Urbanisation, Inflows, Cropping area, NDVI

Raster sub-setting is done to select the desired area or bands of the raster image on which the user wants to perform analysis. Raster sub-setting is done in two ways:

Spectral subset: Spectral sub-setting is done to extract few desired bands from the multiband raster image which are required for analysis.

Spatial subset: Spatial sub-setting is done to minimize the area or extent of raster image to the desired area or extent for further analysis.

Raster sub-setting in R is done by functions available in the ‘raster’ package. The following packages are required in this chapter:

Supervised classification is the technique to classify raster image in which prior information about the classes in the form of training sites is provided by the user. Training site represents a homogeneous area in a particular class. The spectral response pattern of training sites is used to classify the raster image.The pixels of raster imagewhich have spectral response pattern similar to that of training sites of a particular class are grouped in that class. As there is some variability in the spectral response pattern of a particular class, therefore, multiple training sites per class are taken for supervised classification. Supervised classification of raster images can be performed by various methods. Conventional methods include maximum likelihood classifier, minimum distance to mean classifier, and parallelepiped classifier. Now a days, machine learning algorithms are also gaining importance in this context. These classifying algorithms are first trained or calibrated using the data of training sites.This trained model is then validated on the independent datasets for accuracy assessment. If the accuracy of the developed model is of acceptable level, then that model is used for the classification of raster data.

In this chapter, we are going to discuss the execution of maximum likelihood classifier and few machine learning techniques for supervised classification of raster image in R software. The training sites used in this exercise are in the form of points shapefile. The raster image is classified into six classesi.e. built- up, fallow soil, riverine sand, salt-affected soil, vegetation, and water. For performing this exercise, first of all,set the working directory and import the required packages.

Abstract

The state of Tamil Nadu has a low easterly gradient slope and there are number of rivers, big and small originate from the west flow towards east south easterly and confluence the Bay of Bengal. These were grouped into seventeen major and minor river basins, the Cauvery being the largest basin and the river is also a near perennial river. These river basins receive rainfall both from the southwest and northeast monsoons. The state has over 40,000 surface water bodies and number of major dams and reservoirs. Even then, since the rainfall of the north east monsoon, the major source of water source to these basins, occurs in short span of few days with high rainfall, neither adequate storage is there to store them nor the recharge possibility is available, thus all leading to flooding and wastage. The 40,000 and odd water bodies are heavily silted and polluted too. The paper provides an over view of all these, basin wise, and in addition, strongly advocates intra state river linkage and improvised irrigation management as the best option to save the state from its water deficiency.

Abstract

Tsunami (2004), that struck the Tamil Nadu coast has left deep marks in the minds of the affected society. The interview conducted in the coastal villages of the tsunami affected Nagapattinam has brought out many salient societal issues like, loss of leadership, widow hood, debt grip, psychological depression etc, which warrant deeper look to bring them out from the syndrome.

Keywords: Tsunami (2004), Social issues, Nagapattinam, India

INTRODUCTION

The damages caused by tsunami (2004) along the coastlines of most of the South Asian countries are indelible not only from the minds of the coastal population but also from the heart of the entire humanity. The worst affected in the disaster are the fishing community. Many of their mechanized and un-mechanized boats and catamarans were converted to useless debris and garbages by the heartless tsunami. When their settlements themselves were swallowed even with out chewing, nothing to talk about their fishing nets which were just blown off by the ferocious tsunami. In addition, the infrastructure facilities like roads, communication systems, water and power supply were also incalculably damaged. Next to fishermen community, the affected souls were the farmers whose cultivable lands were turned into marine wet lands with swimming and tossing fishes. The Indian subcontinent was facing such onslaughts of various natural disasters periodically but our morale always stood by our side prohibiting us declaring them as national calamities for getting international aids. Specifically in this case, the central and state governments, NGOs and Voluntary Organizations have risen phenomenally to help the affected who were in need. Despite best efforts taken to provide relief and rehabilitation to the affected people, the tsunami has seedled some societal issues / syndrome, which may take long years to settle; it may not settle too. The paper discusses some of such issues gulled out through the interview conducted amongst various cross sections of the affected community.

ABSTRACT

The exponential growth of population and rapid industrialization, urbanization, deforestation and improper landuse practices have led to depletion and pollution of surface and ground water resources in Tamilnadu, India. In addition, a recurrent monsoonal failure further aggravates the problem of water even for drinking water. Water plays vital role in our day to day life and other developmental activities in the area. Thus, the availability of surface and sub surface water potential governs the processes of planning and development. The surface water resources are inadequate to fill the water demand and productivity through ground water is quite high as compared to surface water. Keeping this in view, the present study is aimed to identify the potential location of potable groundwater exploration in hard rock terrain. Thematic information on geomorphic landforms, Landuse/landcover and lineament details are extracted from remotely sensed data. Geology, Soil class, Drainage network and Slope map of the terrain were prepared using existing maps and collateral data by conventional method. GIS based model was developed and appropriate rank and weightage had been assigned to all categories based on local conditions/variations in each layer according to relative contribution towards the desired output. Since the present study built with logical condition and reasoning rule based approach for groundwater targeting, it has been successfully used and clearly demonstrated the capability of Remote Sensing and GIS techniques in identification of potable ground water potential zones.

Abstract

The tectonic and the geomorphic features observed along the west coast of the area between Mangalore and Cape Comorin show that the NNW-SSE trending west coast has been carved out by the Western Ghats orogeny and the related NNW-SSE trending release fractures. The sinuosity of the otherwise straight coast line is due to Quaternary cymatogenic arching caused by the thrust related to the northerly movement of the Indian plate. The coast line has further attained peaks, projections and serrations due to the ENE-WSW trending series of Precambrian extension fractures which were reactivated gaining the northeasterly directed forces from the rising Carlsberg ridge. Overall, the west coast is being tectonically evolved even today due to the rise of Carlsberg ridge and the Indian plate movement.

Abstract

The analysis of IRS - 1A satellite imagery has indicated the existence of two NE - SW trending sub parallel faults along which the coast is undergoing land subsidence as revealed by the concavity in the shore line, preferential migration of the river systems and the drainage congestion, absence of beach ridges, occurrence of off shore shoal etc. The study has further indicated chains of tectonically induced environmental problems such as ground water logging, coastal zone flooding, storm surges, harbour sedimentation etc.

33. GEOTECTONICS

Introduction

Geotectonics is the branch of geology which deals with the structure and movements of the earth’s crust. It includes the study of large-scale features like mountain chains, mid-oceanic ridge and oceanic trenches. Investigation regarding the form, pattern and genesis of these, and other tectonic units have enabled geo-scientists to ascertain the important characteristics of earth’s crust and reconstructs its evolution and geological history.

33. GEOTECTONICS

Introduction

Geotectonics is the branch of geology which deals with the structure and movements of the earth’s crust. It includes the study of large-scale features like mountain chains, mid-oceanic ridge and oceanic trenches. Investigation regarding the form, pattern and genesis of these, and other tectonic units have enabled geo-scientists to ascertain the important characteristics of earth’s crust and reconstructs its evolution and geological history.

Abstract

The present study has revealed that the NE-SW and WNW-ESE trending sinistral faults are very active along the Tamil Nadu coast and the same have caused considerable slope modifications along the Coleroon and Karungalar rivers which are well-manifested in the land, water and mudflat distribution pattern. Similarly, the progradation of the land in Vedaranniam nose is due to the rise of Pattukottai-Mannargudi area and the time transgressive modifications of the Vedaranniam backwater indicates the opening up of the N-S trending Pleistocene-Holocene faults.

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.