Disaster Management

About the Authors Dr.K.Palanivel, Assistant Professor, Centre for Remote Sensing, Bharathidasan University, Tiruchirappalli has over 16 years of in depth expertise in GIS in Water Resources and further specialized in Spatial Support Systems (SSS) for Natural Resources Management and Natural Disasters Mapping Mitigation and Management. He has published over 29 scientific papers in referred journals, edited volumes and conference proceedings and edited a special volume on Geospatial Technology for Developmental Planning. He is a member in number of academic societies. Dr.J.Saravanavel, Assistant Professor, Centre for Remote Sensing, Bharathidasan University, Tiruchirappalli he has over 15 years’ experience and expertise in the field of Remote Sensing and GIS in Earth System Sciences with special reference in Neo-Active Tectonics and its control over natural resources, environment and natural disasters. He is a specialist in GIS based visualizations and published over 25 scientific papers in journals and books. Dr.S.Gunasekaran, Scientist, Centre for Remote Sensing, Bharathidasan University, Tiruchirappalli has over 14 years of in depth experience in Remote Sensing and GIS in Surface and Groundwater Resources, GIS based 3D modelling and GIS based district level Developmental Planning. He has contributed significantly to both academic and research activities in Centre for Remote Sensing, Bharathidasan University and published over 20 papers.

Disaster

Management

Disaster

Management Editors

K. Palanivel J. Saravanavel S. Gunasekaran

Organized by Revenue Administration, Disaster Management & Mitigation Department, Chennai Irrigation Management Training Institute Thuvakudi, Tiruchirappalli Centre for Remote Sensing Bharathidasan University, Tiruchirappalli

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Published by Sunil Sachdev and printed by Ravi Sachdev at Allied Publishers Pvt. Ltd. (Printing Division), A-104 Mayapuri Phase II, New Delhi-110064

Dr. T.S. Sridhar, I.A.S. Additional Chief Secretary Commissioner of Revenue Administration Disaster Management & Mitigation Department Chepauk, Chennai-600 005

Foreword The State of Tamil Nadu is located in the vulnerable part of the Indian Peninsula and subject to both climate and geological disasters such as cyclone, flood, earthquakes, tsunami and drought. Government of Tamil Nadu has been taking number of significant steps in the field of Disaster Management to tackle disasters effectively and provide immediate relief to the affected people. There has been greater focus on pre disaster preparedness and capacity building of stakeholders involved in Disaster Management. Various capacity building activities are being undertaken out of the13th finance commission funds, and under one such activity funds have been sanctioned to Irrigation Management Training Institute, Thuvakudi, Tiruchirapalli for preparation of Modules on Disaster Preparedness Mitigation and Management and for conducting Training programmes in their Institute. The Institute has come up with a book on Disaster Management authored by faculty from Centre for Remote Sensing, Bharathidasan University, Tiruchirapalli. The book is comprehensive with more scientific data useful for Disaster Management update their knowledge. I congratulate the Irrigation Management Institute, Thuvakudi, Tiruchirappalli, Centre for Remote Sensing, Bharathidasan University, Tiruchirappali and the Authors of the Book Dr.K.Palanivel, Dr.J.Saravanavel and Dr.S.Gunasekaran of Bharathidasan University for taking efforts to bring this comprehensive book on Disaster Management.

Centre for Remote Sensing, Bharathidasan University, Tiruchirappalli-620023

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Preface IMTI

Dr. V.M. Muthukumar

Vice-Chancellor, Bharathidasan University

Message

of Vice-Chancellor Natural Disasters like earthquakes, cyclones, floods, landslides, tsunamis, volcanic eruptions, etc., cause heavy loss of life, property damage, etc., and severely affect the economy in many countries, especially in the developing countries. For instance, The Asian Mega Tsunami that occurred a decade ago shook all the territorial nations in South Asia leaving hundreds of thousands of people and cattle dead and india had to spend an enormous amount of money on its relief and rehabilitation measures. Similarly,the Uttarakhand - Kedarnath episode and the recent Hudhud cyclone that devastated Visakhapattinam coast proved greater insecurity to human lives. Nevertheless, higher technologies like Remote Sensing, GIS (Geographic Information System), GPS (Global Positioning System),etc., have emerged as credible tools in providing possible remedies to the natural disasters. Ever since its inception, the Centre for Remote Sensing of Bharathidasan University has been doing exclusive and excellent researches on natural resources and natural disasters. This book will be a comprehensive source of most useful information on Disaster Management. I congratulate the authors, Dr. K. Palanivel, Dr. J. Saravanavel and Dr. S. Gunasekaran, on their effort in bringing out this book.

17 November 2014

Dr. V.M. Muthukumar Vice-Chancellor

Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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Preface IMTI

Foreword The natural disasters viz., Earthquakes, Landslides, Floods, Tsunamis, etc., have become the recurring disasters all over the world. In the Indian subcontinent, though the disasters like earthquakes, landslides and floods were mostly confined to The Himalayas in the past, now it started spreading to all over the Peninsular India. The major earthquakes of Killari (1993), Jabalpur (1997), Kutch (2001) and the moderate to low order seismicities occurring almost in the entire country; the occurrence of landslides in almost all the mountain regions of the country and floods in parts of Maharashtra and Gujarat, along most of the Bay of Bengal bound rivers and even in the desertic tracts of Rajasthan stand as testimony for the same. The Asian Mega Tsunami 2004 has opened up yet another new chapter in the hierarchy of natural disasters. The recent Kedarnath-Uttarakhand floodlandslide episode which shattered the whole Uttarakhand state and the Asian Mega Tsunami that devastated the coastal states of India a decade back have taught us lessons that despite the invention and the advancement in space and computer based spatial technologies and the studies by many government, quasi-government and academic institutions in disaster mapping, mitigation and management, the country is yet to go a long way to have comprehensive disaster management strategies. The Centre for Remote Sensing, Bharathidasan University, one of the few centres in the country with proven credentials in advanced academics, research and extension in Remote Sensing, GIS, GPS, etc., in the focused areas of Earth System Sciences including the natural disasters, has been researching in the core areas of seismic vulnerability mapping, landslide hazard zonation and mitigation, floods, tsunami, etc., for the past two decades. Distilling the data and the wisdom gathered, the authors Dr. K. Palanivel, Dr. J. Saravanavel and Dr. S. Gunasekaran thought it fit to bring out a comprehensive book on ‘DISASTER MANAGEMENT’. Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Foreword Preface I compliment the authors for their painstaking efforts and I am confident that this will provide the basic stimuli for the beginners and a reference material for all the researchers and the managers in areas of natural disasters.

Dr. S.M. Ramasamy DST Geospatial Chair Professor Centre for Remote Sensing Bharathidasan University, Tiruchirappalli and Former Vice-Chancellor Gandhigram Rural Institute-Deemed University, Dindigul

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Preface IMTI

Er. B. Rajeswari, B.E.

Chief Engineer, PWD & Director, IMTI

Message

of IMTI Director Disasters like earthquakes, cyclones, flood, drought and fire etc., are claiming thousands of lives every year globally. Flood alone destroys 5.00 crores acres of paddy fields in Asia, the value of which is around Rupees one lakh crores. The recent heavy monsoon downpour caused submergence of more than 53000 acres of paddy fields in delta districts of Tamil Nadu. Therefore Disaster mitigation strategies, are felt urgent need of the hour. Irrigation Management Training Institute, Trichy is one of the partner institutes joining hands with the Revenue Administration, Disaster Management and Mitigation Department, Government of Tamil Nadu, in organizing and conducting Disaster Management Training Programmes to the officers of various departments. To facilitate inculcation of knowledge and skills on Disaster Management techniques to the trainees, a wonderful book on ‘DISASTER MANAGEMENT’ has been brought out by this institute. Thanks to the funding agency- the Revenue Administration, Disaster Management and Mitigation Department Government of Tamil Nadu and the Centre for Remote Sensing, Bharathidhasan University, Trichy, Faculty members who offered their intelligence and skills as inputs in making the book. This book is going to be a treasure of knowledge to those who are engaged in the noble cause of public welfare and development. I wish everyone those who involved in disaster management should read this excellent book and update their knowledge, which would help to save thousands of human lives and properties. Place: Tiruchirappalli Date : 05.11.2014 Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023 ix

Preface IMTI

Preface Natural Disasters have become the growing epidemic all over the world. Until 20th century, our Indian subcontinent faced few disasters like Earthquakes and Landslides mostly confined to the active Himalayan mountain belt and adjacent foot hills and Floods or Drought occurred rarely in some plains. But, recently, these disasters have started recurring all over the country. For example, the recent earthquakes in Kutch and Madhya Pradesh caused greater casualty is one such signal that the whole Indian Peninsula is prone for seismicity. The seismicity of moderate to low intensities is regularly occurring in parts of Gujarat, Madhya Pradesh, Kerala, Pondicherry and Tamil Nadu too. The cracks that are developed in the buildings and the collapse of the wells in the coastal belts of Kerala, visibly felt ground shaking in parts of Madras and Pondicherry region during earthquakes and also in other parts of Indian subcontinent, indicate that the seismicity of whole India need to be studied in detail. Similarly, the Landslides and Debris flows confined to the Himalayan Mountains for many centuries because of the active tectonic movements, have subsequently crippling the Western Ghats of Maharashtra and Kerala and the junction point of Western Ghats and Eastern Ghats, namely the Nilgiri Mountains. Now almost all the mountain belts of India facing the onslaughts of Landslides and it is greatly attributed to the haphazard developments going on in these mountain belts. Likewise, the floods were synonymous with Himalayan originated rivers. But, now even the Thar Desert of Rajasthan is getting flooded and the recent floods in Mumbai, Rajasthan, Kosi river basin of Uttar Pradesh and Bihar, and Jammu & Kashmir floods showed that the flood phenomena also started crippling the whole country. It is true even with Tamil Nadu state that whenever excessive rainfall occurs in Karnataka, the Cauvery basin gets flood. Again the rain fed rivers like Vaigai and Tamraparani gets flooded once in five years causing substantial devastations. Again the Tsunami, which was heard only by our ancestors and seen in Tamil/Hindi Literature, though the Makran 1945 event was a bigger Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Preface disaster, has now opened a new chapter in the Tsunami vulnerability of the 5,000 km long east coast of India. The drought and the cyclones are the regular visitors in the Indian Sub-Continent. Under this backdrop, if the state of Tamil Nadu is reviewed, then it has also emerged as a multi hazard prone province in India. But duly realising this, the Government of Tamil Nadu under Tamil Nadu State Disaster Management Agency (TNSDMA), has initiated a number of programmes. One such activity is conducting of various training programmes in order to train the man power in understanding various disasters, prepare them to manage and mitigate the disaster with better understanding and act accordingly. In this connection, the Irrigation Management Training Institute (IMTI), Thuvakkudi located in Tiruchirappalli was assigned the work of conducting training programmes on Disaster Management, various awareness programmes, etc., by the TNSDMA. To prepare a very detailed document pinpointing the natural causes and effects of various disasters, particularly to use as a training manual, the Centre for Remote Sensing (CERS), Bharathidasan University (BARD) was assigned the task of writing a comprehensive book on Disaster management by the IMTI, as our Centre is one of the leading centres in India, carrying out various Research and Development studies related to different disasters in addition to various academic and research works. This book on “DISASTER MANAGEMENT” is designed with more attention to simply brief the important concepts and the natural geosystem processes involved in natural disasters. This book will definitely provide a comprehensive view to its readers about various disasters, their origin, natural and anthropogenic parameters that are inducing them and the site specific management/mitigation plans. The authors acknowledges the Tamil Nadu State Disaster Management Agency, Government of Tamil Nadu, Chennai and Er. B. Rajeswari, Director, Irrigation Management Training Institute (IMTI), Thuvakkudi, Tiruchirappalli for allotting this work to our Centre and extending all the supports to bring out this book successfully. Sincere thanks to Er. K. Manuraj, Superintending Engineer and Er. P. Jegan, Assistant Engineer, IMTI, Tiruchirappalli for their support. DST Geospatial Chair xii


Preface IMTI Professor Dr. S.M. Ramasamy, the founder of this Centre for Remote Sensing and the former Vice Chancellor of Gandhigram Rural University, Dindigul is gratefully acknowledged for his untiring and ever blooming fatherly support. Professor Dr. V.M. Muthukumar, Vice Chancellor, Bharathidasan University, Tiruchirappalli is gratefully acknowledged by the authors for the constant supports and for providing Foreword to this book. The authors are unanimously thanking and acknowledging the Emeritus Professor, the formerly Professor and Head of Centre for Remote Sensing, Dr. C.J. Kumanan for his outstanding brotherly guidance and support extended in all possible ways to bring out this book in a good shape and to complete this work successfully. The ungrudging support provided by our Head of the Centre for Remote Sensing, Dr. D. Ramesh, Associate Professor is thankfully acknowledged. Mrs. D. Gayathri, Scientist who has assisted in developing SDSS (Spatial Decision Support System) in GIS for both Natural Resources and Disasters, need to be specially acknowledged. Finally the authors also acknowledge Mr. N. Ramalingam and Mr. D. Madhavan, Research Scholars and the other Staff of Centre for Remote Sensing for their valuable support in all possible ways. Last but not least, though the studies that have been frequently referred in the book were the author’s works, these have been carried out under the guidance and leadership of Prof. S.M. Ramasamy through his various research programmes and projects. So the authors convey their special acknowledgments to Prof. S.M. Ramasamy for having consented to distill those ideas in this book. November, 2014 Tiruchirappalli, India

Palanivel K. Saravanavel J. Gunasekaran S.


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Preface IMTI

Contents Message of Vice-Chancellor ............................................................................. v Foreword .......................................................................................................... vii Message of IMTI Director ................................................................................ ix Preface .......................................................................................................... xi Chapter–I: Introduction ................................................................................ 1 How this Book is Organized? ........................................................................... 5 Chapter–II: Earth System Processes and Chains ....................................... 7 of Disaster Occurrences 2.1 Earth System Processes ............................................................................. 7 2.1.1 Plate Tectonics – Earth’s ever ending processes ............................. 10 2.1.2 Geomorphic Agents and their Processes ......................................... 15 2.1.3 Earth’s Atmospheric and Oceanic Circulations .............................. 16 2.1.4 Changes in Sun’s output Radiation and Solar Flares ...................... 19 2.1.5 Self rotation, Orbital Revolution around Sun and Universe ........... 19 2.2 Chains of Disaster Occurrences . ............................................................... 20 Chapter–III: Classification of Disasters ....................................................... 22 3.1 3.2

Disaster Classification Based on Time Duration to Occur ........................ 23 3.1.1 Rapid Occurring Disasters .............................................................. 23 3.1.2 Slow Occurring Disasters . .............................................................. 24 Disaster Classification Based on Inducing Parameters . ............................ 24 3.2.1 Natural Disasters ............................................................................. 26 3.2.2 Natural Disasters Induced by Human Interventions ....................... 33 3.2.3 Exclusive Human-made Disasters . ................................................. 35

Chapter–IV: Disaster Vulnerable Area Mapping, Mitigation, ................. 36 Damage Assessment and Management— Application of Geomatics Technology 4.1 Earthquake ................................................................................................. 37 4.2 Landslide ................................................................................................... 45 4.2.1 Geomatics Based Models on Landslide Hazard Zonation .............. 45 4.2.2 Landslide Mitigation ....................................................................... 49 4.3 Cyclone ...................................................................................................... 49 4.4 Flood .......................................................................................................... 54 4.4.1 Application of Geomatics Technology in Mapping ........................ 55 Flood Vulnerable Zones Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Contents Preface 4.4.2 Identification of Causative Parameters and Flood Mitigation.......... 64 4.4.3 Feasibility of Flood Water Harvesting............................................. 67 4.5 Soil Erosion ............................................................................................... 69 4.5.1 Mapping of Soil Erosion Areas using Geomatics Technology ....... 69 4.5.2 Geomatics Based Detection of Causative Parameters .................... 71 of Soil Erosion and Mitigation 4.6 Tsunami ..................................................................................................... 76 4.7 Drought ...................................................................................................... 80 Chapter–V: Disaster Information System .................................................... 83 5.1 Requirement for Disaster Information System .......................................... 83 5.2 Designing of Disaster Information System ............................................... 86 5.2.1 Information Retrieval .................................................................... 86 5.2.2 Layer Wrapping ............................................................................. 91 5.2.3 Zooming . ....................................................................................... 91 5.2.4 Other Map Handling Tools . .......................................................... 91 5.2.5 Data Listing ................................................................................... 91 5.2.6 Distance Measurement .................................................................. 92 5.2.7 Data Updation . .............................................................................. 92 5.2.8 User Defined Query Based Map Display ...................................... 92 5.2.9 Display of User Defined Feature Label ......................................... 92 5.2.10 Hierarchy of Data .......................................................................... 93 5.2.11 Co-Ordinate Information ............................................................... 93 5.2.12 Display of Attribute Table Field names and Help Note ................ 93 5.2.13 Special Credentials of SDSS ......................................................... 93 5.3 Provision of Links with Relevant Agencies/Departments . ....................... 94 Chapter–VI: Pre-, During- and Post-Disaster ........................................... 95 Events and Do’s and Don’ts 6.1 6.2 6.3 6.4 6.5

Earthquake ................................................................................................. 95 Landslide ................................................................................................... 99 Cyclone ...................................................................................................... 99 Flood .......................................................................................................... 102 Tsunami...................................................................................................... 105

Chapter–VII: Summary.................................................................................. 114 References . ...................................................................................................... 116

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Introduction IMTI CHAPTER – I

Introduction

D

isaster—the word used by the French, Greek, Italian and other ancestors is giving a meaning that, whenever the alignment of stars in bad position, a bad event will happen (pejorative prefix δυσ- [dis-] “bad”+ αστήρ [aster] “star”). From the societal point of view, an extreme event within the Earth’s system that results in death, injury to humans and damage or loss of valuable goods is called as a ‘Disaster’. Scientifically, behind every natural disaster that occurred on the Earth’s surface, at least a single, or a multiple Geological phenomenon or Earth System processes are there in an active, continuous, systematic and in a cyclic manner. These natural phenomenon or processes vulnerable to human and other living being, their property as well as environment are known as ‘Geohazards’. Whenever a society is facing a huge loss or damage to the life and/or the human’s property and/or damage to its environment due to geohazards, then that event is called as a ‘natural disaster’. Hence, all the geohazards cannot become disasters because only few hazardous events are causing disasters. For example, lightening and thundering hitting a vacant land, huge landslides or glacial avalanches in a non-habited interior mountain belts, heavy flood amidst a forest are all geohazards but these are not turned to disasters till there is no such destruction to the human’s life or his property. But, it is very clear from the Geological facts and findings that, all the natural disasters are the results of the continuous, ongoing and cyclic Earth System Processes that are happening from the birth of our mother Earth, i.e., for the past 4.5 billion years. Now-a-days, our human community have started facing disasters very frequently. This is because of our own intervention with the nature improperly through the various developmental activities and implement haphazardly without understanding such natural Earth System Processes. For any sort of disaster management activities that includes, disaster Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Introduction vulnerable zonation or hazardous area mapping, disaster prediction and mitigation, or monitoring such events during disaster or assessing the damages caused after a disaster, it would be very opt, if we understand the Earth System Processes and then plan or involve in such activities. On such proper planning, during these disastrous natural events, our disaster management goals would be achieved rightly in-time and safe guard both our life and property definitely. It is great to know from the science point of view that all the geohazards, though they are destructive, resulted due to various natural cyclic Earth System Processes, geohazards are also constructive. Whenever our interferences with such natural processes are more and more brutal and selfish without understanding the nature, then they become destructive to us. For example, Volcanic is Eruption classified as one of the geohazards vulnerable to become disasters if we live close to them. But, the past several such volcanic eruptions only have played a major role in the primitive formation of this lively atmosphere with all sort of gases and made the land surface as fertile with the volcanic ash for the plants kingdom to bloom rapidly and further with other inorganic mineral deposits and hot springs-geothermal energy resources. Similarly, due to the several past hazardous flooding events, not only the fertile palaeo floodplains and deltas were formed which are highly favorable for our present day agricultural activities, but also the high potential groundwater aquifers (rock / soil formations that can hold exploitable groundwater) were formed, which were naturally recharged and discharged for several thousands of years, and thus holding huge quantum of safe potable water. We are blessed with land, water, mineral and several other natural resources important for our life. These natural resources are developed due to the several Earth System Processes which would be of highly disastrous previously, but they were all can be considered as good disasters for the evolution of human community. We can appreciate the truth of this statement, when we come to know about the extinction of dinosaurs during Cretaceous period due to several natural reasons. Now the people 2


Introduction IMTI started understanding the ill effects of the increased rate of population and the resulted unscrupulous exploitation and pollution of natural resources without understanding the natural geological processes. Due to the developing human community and the increased water requirement, the groundwater resources have been tapped rapidly and unscrupulously thus declining the groundwater table. Further, the catchments of these potential aquifers are also concealed or obstructed by his various developmental activities through concrete or impervious pavements in towns and cities, as building basements or roads. Thus the regular natural recharge happened so far in such area during monsoon is reduced or nullified.As a result, the groundwater table has gone down to a very deeper level in developing areas, which have initiated several ‘induced natural disasters’ such as crack developing in mega buildings and heavy structures (Dams, Tunnels), land subsidence, desertification, groundwater quality deterioration, etc. The land subsidence reported in Kolkata city (Chatterjee et al 2006) is due to the imbalanced hydrostatic pressure below the ground having recent sediments, attributed to the fast decline of groundwater table. Further, this may induce other sequences of natural disasters such as earthquakes, sea water intrusion and drought too. Moreover, improper disposal of both industrial and domestic wastes into the potential river and land systems carelessly without treating them have resulted the area prone for health hazard and disaster because of the aggressive surface water and groundwater pollution. Similarly, the Plate Tectonism, one of the major primary causative factors for the major disastrous events, is the important rock recycling processes through the movements of continental and oceanic plates at different rates and scales. Due to Plate Tectonics, new lithospheric plate is evolved slowly in one side as a constructive component, and land deformation, collision and subduction are caused in the other side as destructive component. Proper understanding of these Earth System Processes lead us not only to act conservatively while exploiting and utilizing potential resources and to preserve them for future use sustainably, but also to understand the areas vulnerable to different disasters and their inducing parameters. Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Introduction Using the available land, water and other earth born resources, we expand our urban limit very fast with latest technological innovations in all facets of our civilization, by culling trees and converting agricultural lands as multi-story residential areas, laying road networks and develop other infrastructures. Combination of these human interventions have led to minimize the oxygen input and also increased the release of carbon dioxide to the atmosphere. This in turn increased the temperature and climatic imbalance of the area. Thus, the imbalanced climate lead to frequent rain storms, floods and subsequent drought conditions. Hence, urbanization should be properly done to safeguard the living environment which involves some of the important activities, such as, 1) site suitability evaluation before any built up land development, 2) ensure intensive afforestation and enhance waste lands for agriculture as alternate activities for deforestation and conversion of agricultural lands 3) check for the provision of proper and sufficient drainages and sewers, 4) ensure installation and proper functioning of waste water treatment plants, 5) provisions for safe disposal of residues and hazardous wastes, 6) plans for treated water reuse and proper handling of degradable and non-degradable waste potentially, 7) installation and monitoring of rooftoprainwater harvesting structures, etc. Through these activities, it is highly possible for us to safeguard the environment and prevent the induced climatic disasters and to assure a secured life. The unprecedented and ever increase of population have created a heavy demand for both renewable as well as non-renewable resources and led to over exploitation of all such natural resources. Hence, in addition to the ‘induced natural disasters’ discussed in the previous page, we are under the threat of facing several other disasters such as, soil slump, soil erosion, quicksand and unexpected in the quarries and open cast mine workings, induced earthquake due to improper underground mine workings, mine collapse, etc. Hence, it is high time to act properly for the welfare of humanbeing primarily by understanding these ever ending Earth System Processes in general and the local morphodynamic and tectonic processes in particular and then by preparing proper integrated plans, so as to utilize the resources sustainably in a conservative fashion and mitigate the disaster effects. 4


Introduction IMTI Proper integrated planning involves an integrated approach from every point of view that combines different datasets from variety of sources, including preliminary/primary satelliteimage processing, satellite image interpretation and mapping which will bring inducing parameter details so as to understand the Earth System Processes, monitor the situation continuously, coupling the collateral data available from the Government, Quasi-Government and Non-Government Organizations, developing predictive, preventive and process models, and by generating user and planner friendly Spatial Decision Support Systems, all using the advanced techniques available now-a-days called ‘Geomatics technology’ in short or ‘Geoinformatics technology’, also known as ‘Geospatial technology’. The Geographic Information System (GIS) is an important component of the Geomatics technology, which is an ultimate platform and boon in collecting, generating digital spatial and non-spatial databases, providing linkage between these two important digital databases, developing models by incorporating several online spatial and non-spatial inputs, analyzing them and preparing pragmatic action plan maps that are most useful for the planners and decision makers for quick and easy decision making during crisis period. Aerial Remote Sensing, Digital Photogrammetry and Global Positioning System (GPS) are the other important and versatile tools available in Geomatics Technology. This book on ‘Disaster Management’ is planned to provide the base to its readers on certain important concepts of Geosystem / Earth System Processes, the human intervention in combination with natural processes that are causing disasters and the application of Geomatics technology in understanding these processes in detail so as to make pragmatic action plans for disaster forewarning, mitigation, management, damage assessment and rehabilitation activities.

How this Book is Organized? This comprehensive reading material prepared for the Junior and Middle Level Officers/Civil Engineers of Public Works Department of Tamil Nadu is organized with seven chapters covering most of the aspects of disasters Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Introduction and their management. After the brief introduction in this 1st chapter, the ever ending important Geosystem processes and the disaster chains are discussed briefly in the 2nd chapter. The two major types of disaster classifications are dealt in the 3rd chapter. A variety of applications of Geomatics technology for disaster management are discussed in the 4th chapter. The ultimate aim of preparation of Disaster Information System for the planners for quick and easy execution of strategic plans during crisis period is briefed in the 5th Chapter. The Do’s and Don’ts prescribed by theGovernment and research organizations for the common civilians related to important disaster events are given in the 6th Chapter. The 7th Chapter summarizes the points that are discussed in the previous chapters and ended with certain remarkable references for the readers so as to enhance their knowledge through further readings. The details regarding the method of satellite image interpretation, digital database generation, data analysis, modeling and information system development are discussed in this book in order to facilitate the readers to understand the advancing and highly useful nature of Geomatics technology in disaster management activities.

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Earth System Processes and Chains of Disaster Occurrences IMTI CHAPTER – II

Earth System Processes and Chains of Disaster Occurrences 2.1 Earth System Processes

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isaster events can be mitigated or, even fully prevented or, forewarned through 4 steps. They are: 1) understanding the roots and causes, 2) determining such vulnerable zones, 3) pragmatic, and precise planning for implementation, and 4) preparedness activities. If the people involved are known/aware about the Earth System Processes, it is quite simple to go through all these 4 steps in order to mitigate/manage with the natural disasters. It is very interesting and important for the map makers, planners, decision makers, implementers and monitoring engineers to know about the birth and the activities of our Mother Earth. In this chapter, let us see how our Mother Earth has born and its regular, natural dynamic and cyclic processes briefly. According to the Nebular Hypothesis, a huge, hot gaseous rotating nebula consisting of clouds of spiraling dust (Figure 2.1a), consisting of Hydrogen, Helium and heavier elements ejected by supernova—a giant explosion, started cooling and contraction due to energy lost by radiation and the shockwave produced by the nearby supernova. Contraction has led to the gravity development. Because of cooling and contraction, the nebula started rotating faster and faster in order to conserve angular momentum (Figure 2.1b). As a result, a centrally bulged Sun was developed surrounded by the disc of nebula (Figure 2.1c). But at the boundary region of the nebula, due to rapid rotation, the centrifugal force becomes equal to the gravitational force and led to the formation of a strip of outer orbiting portion of nebula. Similarly, different orbital strips of nebula were formed due to cooling and continuous contraction of inner portions (Figure 2.1c). Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Earth System Processes and Chains of Disaster Occurrences In the course of time, these strips were accumulated due to collision and condensed further into spherical planets (Figure 2.1d). This way, all the planets were formed around the sun (Figure 2.1e).

Fig. 2.1 a, b, c, d & e: Shows the Formation of Solar System

Since our Earth is nearer to the Sun, cooling and the condensation process took a little longer time than the other outer planets. As a result, the Silica, Aluminium, Magnesium, Iron and Nicol materials within the Earth had enough time to separate and settle themselves based on their specific gravity into three spherical inner layers of the Earth. This process of separation of materials in to three different layers is referred as ‘differentiation process’. The three layers thus formed during the development of our inner Earth are namely, Core, Mantle and Crust (Figure 2.2). The core, located at the center of our Earth at a depth of 2900 to 6378 km from the surface, under very high pressure (3180 kilobars) and temperature (5430°C) conditions, is made up of two sub-layers, i.e., Inner Core and Outer Cores. The Inner Core is in solid form made up of Nickel and Iron (NiFe). Due to the very high pressure of the Inner Core, the melting point of ‘NiFe’ is dramatically increased greater than its normal melting point. Thus, the Inner Core is in solid form, though it is under very high temperature, greater than the normal melting of Iron and Nickel. The Outer Core, which is surrounding the Inner Core, is in liquid form with similar composition (NiFe). 8


Earth System Processes and Chains of Disaster Occurrences IMTI The Mantle, surrounding the Core, located at a depth of 100 km from the Earth’s surface and extends up to a depth of 2900 km, is composed of Iron and Magnesium (FeMa) in plastic or semi-solid/semi-liquid condition due to the high temperature (3000°C) and pressure (1400 kilobars) conditions. But, the pressure at Mantle becomes lesser than half times as that of the Core. The Mantle can be further divided into two namely, Lower Mantle and Upper Mantle based on the recognizable density variations studied through the recorded seismic waves, propagated within the Earth because of the strong earlier Earthquakes. Above mantle, a very thin layer as a shell, like that of an egg, had formed on the surface of the Earth, called the Crust (Figure 2.2). It is classified into two kinds based on the chemical constituents and physical characters attained during its formation. They are: 1) Continental crust – made up of Silica and Aluminium (SiAl), 2) Oceanic Crust – made up of Silica and Magnesium (SiMa). The Crustal plate/Lithosphere, a spherical, upper most layer, extending up to a maximum depth of 100 km from the Earth’s surface includes a little upper most portion of the Upper Mantle and the entire Crust (consist of Continental and Oceanic Plates).

Fig. 2.2: Inner Layers of the Earth Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Earth System Processes and Chains of Disaster Occurrences Asthenosphere is located approximately 100 to 350 km beneath the Crust, in the Upper Mantle. This is a low velocity zone for the travel of seismic wave, wherein the mobile basaltic magma is generated and volcanic chambers are located.

2.1.1 Plate Tectonics – Earth’s ever ending processes Due to the very high temperature of the Core and very low temperature of the Crust, ‘convection cells’ are formed inside the Earth (Figure 2.3). As a result, over the surface of the Crust, three types of margins/boundaries have been developed. They are: 1) Divergent, 2) Convergent and 3) Transform margins (Figure 2.4).

Fig. 2.3: Convection Cells below the earth and Their Effects on the Surface

Different combinations of Continental and Oceanic crusts forming boundary margins over the surface of the Earth and plate tectonic movements over asthenosphere are clearly shown in Figure 2.4. The divergent and convergent margins are controlled by the convection cells below them. At the divergent margin, two adjacent convection currents are coming up from the deep hot core to the cool crustal surface, wherein, magma comes out and concealed and thus a new oceanic crustal strip is formed (Figure 2.4). The long and linear vent formed at the middle portion, where magma comes out slowly as lava and cooled rapidly due 10


Earth System Processes and Chains of Disaster Occurrences IMTI to the ocean water above it and thus acquiring little higher elevation than the surroundings as a ridge is known as Mid-oceanic Ridge (Figure 2.3). As a complement and consequence, the other two adjacent convection cells located on either side moves towards each other and sink into the Lower Mantle. These convection cells moves the crustal plates towards each other. At one stage, the two crustal plates collide. This margin where in, the collision of crustal plates is taking place is called as ‘convergent margin’.

Fig. 2.4: A Portion of the Earth’s Crust and Upper Most Mantle in 3D View, Showing Convergent, Divergent and Transform Boundaries

As a result of collisions of plates, Trenches, Folded or Volcanic Mountain chains and Island Arcs are formed on the other side (Figure 2.4). The Himalayan Mountains are developed as a result of continentalcontinental convergence, due to the collision of Eurasian and Indian plates. The Andaman and Nicobar islands are the Island Arcs, developed due to the same collision of Indian-Australian Oceanic and Eurasian Oceanic plates (Figure 2.5). Other than these convergent and divergent activities, transform margins are also formed at places, where the plates are slipped each other horizontally. The rate of movement of continental and oceanic plates is determined by the convection cells below the crust and the dimension and rigidity of the plates (Figure 2.5). Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Earth System Processes and Chains of Disaster Occurrences

Fig. 2.5: Three Different Boundaries on the Earth’s Surface

Because of the movement of these plates, stress accumulation followed by the generation of seismic waves due to sudden release of pressure happens through breaking and sliding of plates. Thus several geohazards are induced naturally and hence there is a great possibility for the occurrence of disasters to the living community and the infrastructure developed by humans on these crustal plates, in the form of Earthquakes, Tsunami, Landslides, Rock falls, etc. Along or nearer to the plate margins, as a result of collision or divergence of plates, several volcanic activities are going on and recorded. These margins located with chains of volcanoes are known as ‘Ring of fire’ (Figure 2.6). The scientific study of movements and collision of lithospheric/ crustal plates over the asthenosphere as a result of underlying internal convection cells is known as ‘Plate Tectonism’. Hence, in total, the crustal plate is undergoing a natural, rock recycling process either through Plate Tectonism or Petrological Cycle process is kept on continuing from the origin of the Earth. Thus, the geologists have started studying the crustal plate movements (known as ‘Continental Drift’) and deformations with 12


Earth System Processes and Chains of Disaster Occurrences IMTI

Fig. 2.6: Locations of Volcanic Activity (Yellow dots) Along Plate Margins as Ring - ‘Ring of Fire’

specific lights on such locations, dimensions and stress release timings and the related seismo-tectonic/geomorphic changes and the resultant effects. As mentioned, due to the plate tectonic movements, the crustal plates are crippled under compression or expansion pressure/stress conditions. Due to continuous accumulation of stress condition because of continentalcontinental collision, the crustal plates may undergo lots of deformations, such as mountain building, fractures development and faulting. During sudden deformation in the form of faulting, seismic waves will generate and propagate with high velocities by shaking the crustal rock mass, is known as ‘earthquake’. The earthquake waves shall destroy the features and infrastructures that are available on its path of travel and cause major disaster. During the stress accumulation within crustal plates due to collision of continents, like a plastic the crust will try to adjust the stress/pressure exerted in the form of local swelling up and deepening down slowly as a crawling worm. If one area is getting uplifted continuously, then, a mountain range may get developed. This is known as Mountain Building Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Earth System Processes and Chains of Disaster Occurrences Processes. For example, the Himalayas, which is still under compression by plate tectonic forces and thus it gains elevation with a minimum of 6mm to a maximum of 12 mm per year. Further, the entire Indian Plate experiences the whirling or arching and deepening activities (Figure 2.7), perpendicular to the direction of its movement; i.e. along East-West (Ramasamy and Balaji 1995).

Fig. 2.7: Whirling Effects in Indian Plate (Source: Ramasamy and Balaji, 1995)

Similarly, different types of fractures/lineaments are formed on the crustal surface where plate tectonism is active. Further, the areas where 14


Earth System Processes and Chains of Disaster Occurrences IMTI upliftment takes place, then groundwater level declination and soil erosion will be induced more. Along the deeps or subsiding areas, a lot of deposition of eroded materials will take place. Similar such geohazards such as, sea water intrusion, groundwater pollution and change in the direction of polluted plume as well as groundwater movement, declining of sea level, etc., are also expected forever in different parts of our Earth surface due to natural plate tectonic movements and thus, disasters are resulted as a consequence, naturally. The natural vertical adjustments of continental crusts based on their thickness and density, happened during or after the deformation of crustal plate due to plate tectonic effects, is studied scientifically as ‘Isostasy’. Thus, a variety of geomorphic landforms are developed and classified based on their elevations and the agents.

2.1.2 Geomorphic Agents and their Processes The major and significant agents of geomorphological processes that may cause vulnerability to disaster are: Glacier (ice), Tectonism (plate movements), Denudation (weathering), Aeolian (air), Fluvial (water), Coastal and Marine and their simple or multiple combination is also effectively acting upon and shaping up the Earth’s Crust. These geomorphic agents are still active and thus inducing several disasters on their way of developing different landforms. Hence, apart from the resources that are developed through geomorphological processes, it is also highly important to understand about the geomorphic landforms and their vulnerability to various disasters. For example, in thickly glaciated areas, glacial avalanches (sudden fall of big ice blocks), snow-melt runoff and Lahar (thick slurry-watery clay soil which can move very fast along hill slopes and engulfing villages and infrastructures within short period) and crevices (big cracks amidst the glacier due to slope variation), are the most disastrous features. A Block Mountain developed due to tectonic geomorphic process has fault scarps along fault plane and escarpment slopes. These areas are highly vulnerable for severe soil erosion, landslides, rock falls, rock slumps, etc. Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Earth System Processes and Chains of Disaster Occurrences Similarly, due to denudational processes, different vulnerable slope features are developed and thus disasters such as soil erosion, landslides, rock falls and rock slumps may occur. The Aeolian geomorphic landforms are causing high vulnerability through sand dunes (cause quick sands, engulf the habitations and potential agricultural lands), high speed sand storms and desertification of an area. Flooding, water stagnation, water pollution, formation of quick sand, whirl pool and erosion are some of the consequences of fluvial geomorphic processes. Through the coastal geomorphic processes, again, quick sands, coastal erosion, wavy whirl pool, severe cyclonic storms and flooding are the disasters that could occur obviously. The combined action of different above geomorphic agents along with the Earth’s self-revolution, axis inclination and orbital motion around sun will play very dangerously in setting the local climates and changing the speed of geomorphic processes rapidly. To say simply, many disasters are resulted one after the other as a sequence. The same is dealt as ‘Disaster chains’ latter in this chapter.

2.1.3 Earth’s Atmospheric and Oceanic Circulations Apart from the various Plate Tectonic movements and Geomorphological processes, the Atmospheric and Oceanic Circulations are considered as the major deciding parameters for the existing local climatic variations and thus the resultant climate related disasters due to Cyclone, Hurricane, Typhoon, etc., and ocean accidents and destructions or sinking of passenger ships and cargo ships. Similar to the deep subsurface ‘Convection Cells’ which have caused Plate Tectonic movements on the Earth’s Crust, there are three types of cells (Hadley, Ferrell and Polar cells, Figure 2.8) circulating on the Earth’s Atmosphere in order to balance the heat variation due to latitude effect. The area falling between the Tropics (Cancer and Capricorn) and along the Equator is heated up highly during summer solstice because of the direct hitting Solar Radiations. On the contrary, the Polar Regions will receive only very feeble heat energy from the high oblique Solar Radiations. 16


Earth System Processes and Chains of Disaster Occurrences IMTI The reason is the heat energy lost by reflection, scattering, absorption and refraction of Solar Radiations during the oblique penetration of Solar Radiations through atmosphere makes a long journey to the rays to reach Polar Regions. The local extreme variations in the atmospheric circulations resulted into disastrous climates with cyclones, typhoons and hurricanes. Similar effects and accidents are resulted due to oceanic circulations too.

Fig. 2.8: An Idealised View of Three Large Circulation Cells in the Earth’s Atmosphere

In Figure 2.9, the space photograph taken by an Astronaut from International Space Station (ISS) is showing the Space Shuttle Endeavour seen at the back drop of the boundary between the Earth’s Stratosphere and Mesosphere. Orange colour layer just above the surface of the Earth is the troposphere, where all of the weather and clouds which we typically watch and experience are generated and contained. Above this orange coloured layer is the whitish Stratosphere and then further above is the bluish Mesosphere. At the right side of the photograph is a drawing representing the space above the Earth’s surface. This gives an idea on the height details and different portions of atmosphere and the various Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Earth System Processes and Chains of Disaster Occurrences natural (Meteors, Aurora) as well as human activities (Aeroplane, Weather Balloon, Space station) happening above the Earth.

Fig. 2.9: Space Shuttle Endeavour Appears to Straddle the Stratosphere and Mesosphere

In Figure 2.10, the Meteoritic light streak is seen in Mesosphere at the near center. On its right, a cyclonic spiraling cloud with an eye at its center parallel to the Earth’s surface is clearly visible. Refracted Moon light made the upper layers of Atmosphere highly visible with orange colour at the top right corner, left of ISS solar panel is also clearly visible in this space photograph taken by an ISS Astronaut (Source: NASA Science News website).

Fig. 2.10: Meteoritic Light Streak in Mesosphere at the Near Center and Refracted Moon Light Due to Atmosphere at the Top Right Corner Left of International Space Station

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Earth System Processes and Chains of Disaster Occurrences IMTI

2.1.4 Changes in Sun’s output Radiation and Solar Flares There is a possibility of changes in intensity and duration of incoming solar radiation due to a Variety of geometrical relationships between the Earth and the Sun, Earth’s rotation and spatial differences in the Earth’s atmospheric transparency. Due to the changes in intensity and duration of incoming solar radiation in to the Earth’s surface, there will be a prominent climatic disorders and this may result climatic disasters.

2.1.5 Self rotation, Orbital Revolution around Sun and Universe Variations in the Earth’s orbital characteristics, such as, changes in the Earth’s tilt, variations in the timing of aphelion and perihelion and Changes to the shape of the Earth’s orbital path are the major reasons for a variety of geometrical relationships between the Earth and the Sun (SunEarth Geometry). These changes in geometrical relationships between the Earth and the Sun makes considerable effect on the intensity and duration of increasing/decreasing changes in solar radiation, in turn it affects the normal climate and becomes one of the important reasons for climate change and related disasters. Moreover, several records on palaeoclimatic changes and palaeo disasters are available on the Earth. Palaeoclimatic research studies are showing the Polar Reversals (Polar Wandering), change in the inclination of Earth’s Axis, change in the shape of the Earth’s and Sun’s orbits causing the change in Perigee and Apogee. Further, it is also identified that the Earth’s axis itself rotates and makes precession (slow movement of the axis of a spinning body around another axis). This precession of Earth’s axis takes 26,000 years. It is also predicted that the Earth’s axis of rotation will line-up with Fig. 2.11: Precession of Earth’s Axis— the star Vega after 12,000 years A Climate Influencing Parameter Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Earth System Processes and Chains of Disaster Occurrences from now (Figure 2.11). These facts are mainly influencing the Earth’s climate and accounted for the climatic disasters and other related disasters.

2.2 Chains of Disaster Occurrences Two or more disasters may occur one after the other continuously as a sequence with or without limited time interval, due to any of the Earth’s dynamic and cyclic natural processes initially. This is known as a ‘Disaster Chain’. For example, it is opt to understand, a major disaster chain occurs in our country during every monsoon accelerated due to heavy rain storm and then flooding, followed by spreading of epidemic diseases such as cholera, diarrhea, etc., which is further worsened by water logging, quick sands and the related accidents. A landslide induced by an earthquake during May 2008, had arrested the normal flow of the perennial river named Tangjiashan river of China. The materials dumped through landslide across this river had acted as a big earthen dam. This had resulted in to the formation of Quake Lake in the upstream of the landslide location. Water level of the quake lake had raised to 738.71m on 6th June 2008 and identified that the bursting point of temporary earthen dam was reached. This had threatened more than

Fig. 2.12: Temporal Satellite Images Showing the Formation of Quake Lake

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Earth System Processes and Chains of Disaster Occurrences IMTI 2,50,000 people living in its downstream. More than 600 armed police and soldiers had dug a 475 m-channel to divert the water. Similarly, more than 30 such unstable quake lakes formed during that period. If the quake lake bursts, then the water gets mixed with the debris and flow very turbulently along the slopes as Lahar which can bury the villages on its way rapidly. Similar such event was identified along Pareechu lake in the Tibet region, during April-August 2004 by SAC, Ahmedabad & HPRSAC, India and the information regarding its breeching time (26th June 2005) and the possibilities of making strategic plans through satellite image analysis using GIS (Figures 2.12 and 2.13) were informed to the relevant organizations by ISRO research team (NRSC-2006).

Fig. 2.13: GIS based 3D Model of the Quake Lake

In the same way, Earthquake damages followed by explosion and fire accidents due breakage in domestic gas supply/distribution pipes, flooding due to diversion of rivers or bursting of major reservoir dams are the other examples for disaster chains. Many of the disasters may induce further follow up disasters one after the other and thus make the bad situations very worst in some areas. Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Classification of Disasters CHAPTER – III

Classification of Disasters

M

ost of the disasters occurring on the Earth are resulted due to its natural, dynamic, cyclic and reviving processes. One of the major Earth’s natural dynamic processes, briefed in the previous chapter, is plate tectonics. Other noticeable natural processes are the physical and chemical disintegration, weathering and mass wasting of rocks. After weathering, the dislodged rock materials will be naturally carried down t o the low lying areas through the processes such as, erosion, transportation and deposition by several agents such as wind, glacier, water and ocean waves and currents. These natural processes are useful for the formation of many basic non-renewable resources for the living beings, such as fertile soil, aquifers, hydrocarbon reservoirs, etc. The heavy mineral placers, such as Ilmenite, Garnet, Gold, Diamonds, etc., were also formed as a result. But, during these natural processes, the natural disasters such as landslides, earthquakes, flood, lahar, snow avalanche, etc., will occur too. Hence, the disasters occurring due to ongoing natural processes are named as Natural Disasters. On the other side, the developmental activities of the human being through improper intervention with nature have also increased the degree of occurrence of natural disasters in many folds. They can be classified as Human Induced Natural Disasters. This chapter gives an idea of how the disasters can be classified so as to understand the roots/causes which would be more useful for deciding precise mitigation and management measures. The two important parameters that could be considered for the classification of disasters are: 1. Time gap for the occurrence, and 2. Inducing parameters for the occurrence.

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Classification of Disasters IMTI

3.1 Disaster Classification Based on Time Duration to Occur The natural disasters can be easily grouped based on the time duration for the disaster to occur into two simple classes, they are: 1) Rapid Occurring Disasters and 2) Slow Occurring Disasters.

3.1.1 Rapid Occurring Disasters The disasters that could occur within a short period because of which the area will be destroyed within no time (short period, i.e., few minutes) are classified as ‘Rapid Occurring Disasters’. Some of the Rapid Occurring Disasters are: Earthquake, Landslides, Glacial Avalanche, Volcanic eruption, Asteroid Impact, Tsunami, Dust Storm, etc. In these examples, though some of the disasters will destroy an area within few seconds, they can be predicted early based on their velocity (speed and direction) and nature of origin. Similar such disaster prediction capabilities are developed by several researchers around the World for almost all disasters. In order to manage with these Rapid Occurring Disasters, the planners should have a preplanned setup with well trained-officials/volunteers and the informedpeople about all these plans in advance. Now-a-days, many advanced mapping techniques on disaster vulnerable zones are developed using the latest emerging tools available with Geospatial technology. Natural Hazard Vulnerability maps for all these Rapid Occurring Disasters for the entire country and the mitigation and/or management measures should have been prepared well in advance. It should be followed by adequate and prior training to the relevant people/officials involved. Further, with the help of the Rapid Occurring Natural Hazard Vulnerability maps, the Government can implement the prevention plans suggested for different places. For example: • Geo-textiling and Nailing of debris/rock hang or its removal along hill slopes to avoid landslides, • Neglecting permissions for heavy constructions along sensitive areas which may induce further disasters, • Preventing over exploitation of groundwater and continuous monitoring of hydrostatic pressure imbalance developed through Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Classification of Disasters the subsurface voids because of fast decline of groundwater table, which can induce land subsidence and further seismicity or sea water intrusion into potable aquifers located below coastal cities and towns and making them saline, • Concrete grouting of active fault planes running along disaster prone and sensitive areas and • Identifying safe and alternate places for further future developments, etc. Further, necessary provisions should be made for continuous monitoring of the installed structures and their working conditions so that the Rapid Occurring Natural Disasters can be mitigated easily.

3.1.2 Slow Occurring Disasters The disasters that could take some time to occur can be named under the category ‘Slow Occurring Disasters’. For example, Soil erosion, Drought, Desertification, Coastal Erosion, Ozone Depletion, Coral Reef Decline, Imbalanced Green House Effect, etc., can be considered as ‘Slow Occurring Disasters’. In these examples, though the nature of destruction is different for each disaster, their effect may be recognized over a period of time. However, the soil erosion or drought disasters will occur very slowly and steadily, it is easy to predict early before their occurrence in terms of target areas and nature of destructions that may happen as a result. Thus, it is very important to prepare disaster specific vulnerability maps with inducing parameters based mitigation plans. The mitigation plans might have been implemented properly, the relevant mitigation structures should have been maintained periodically and assure these disasters are prevented/minimized.

3.2 Disaster Classification Based on Inducing Parameters The natural destruction part of dynamic and cyclic geosystem processes lead to various kinds of natural disasters like Earthquakes, Volcanoes, Landslides, Tsunamis, Floods, Land subsidence, torrential rainfall, drought, forest fire, etc. 24


Classification of Disasters IMTI For the past two decades, the human intervention into the Earth ‘s natural processes increased very rigorously and simply neglecting the demolition of non-renewable natural resources through such interventions. Some of the intervening and nature’s destruction activities of humans are: culling of trees for several constructions, over exploitation of groundwater, polluting potential lands, river systems, groundwater aquifers and oceans, etc. As a result, we have been facing a lot of series of natural disasters induced because of such anthropogenic interventions, such as: • Landslides, land slips and rock falls along ghat road sections due to toe removal, • Rigorous soil erosion in deforested area, • Anonymous flooding in cities/towns with ill planned drainages, • Desertification and land subsidence in areas of pollution and over exploitation of groundwater, etc. On the other side, because of the only human error, some of the disasters are occurring such as Stampede, Pollutions, Accidents, etc. Hence, the disasters can also be broadly classified into three classes, based on the inducing parameters. They are: 1. Disasters Induced by Natural Processes called ‘Natural Disasters’, 2. Induced Natural Disasters by human interventions, and 3. Exclusive Human-made Disasters. This particular unit on disaster classification is also providing all the basic information about the different inducing parameters for their occurrence. The transitions between natural and anthropogenic based disasters were dealt by CeesVan Westen 2000 is shown in the Table 1.


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IMTI Classification of Disasters Table 1: Classification of Disaster in a Gradual Scale between Purely Natural and Purely Human-Made Natural

Some Human Influence

Mixed Natural/ Human Influence

Earthquake

Flood

Landslides

Tsunami

Dust storm

Volcanic eruption

Drought

Land Subsidence

Snow storm/ avalanche Glacial lake outburst Lightning Windstorm Thunderstorm Hailstorm Tornado Cyclone/Hurricane Asteroid impact Aurora borealis

Soil Erosion Desertification Coal fires Coastal erosion Greenhouse effect Sea level rise

Some Natural Influence

Human

Crop disease Armed conflict Land mines Insect infestation Forest fire Mangrove decline Coral reef decline Acid rain Ozone depletion

Major (air-. Sea-, land-) traffic accidents Nuclear/chemical accidents Oil spill Water/soil/air pollution Groundwater pollution Electrical power breakdown Pesticides

3.2.1 Natural Disasters 3.2.1.1 Volcanic Eruption Our country had faced a silent volcanic eruption- a natural hazard, during the end of Cretaceous period, i.e. 67-66 million years ago, which might have been the reason for the extinction of dinosaurs in India. Moreover, this eruption had contributed to a climate change to an average reduction of 2 degree Celsius. Recently, the one and the only volcano in Barren Island of Andaman and Nicobar islands had erupted from September 2010 till January 2011. But, since the island itself is barren, without any habitations, this volcanic eruption event was not categorized as Natural disaster. On the contrary, the Sinabung volcano had erupted recently on February 6, 2014. The pyroclastic flows – i.e., the hot lava flow-had swallowed the fertile plantation area in the down slopes covering 10 sq.km and engulfed 15 residents of the village Sukameriah. The natural-color satellite image 26


Classification of Disasters IMTI acquired by Advanced Land Imager (ALI) on the Earth Observing-1 (EO-1) satellite showed the ash plume coming out of volcanic vent and flow deposits appears as light gray long patch with streaks, seen on the southeastern slope of Sinabung’s summit (Figure 3.1). Even now, the remaining more than 30,000 residents of the nearby villages are threatened daily by this volcano. Volcanic eruptions are one of the resultant activities of ongoing natural Plate Tectonic processes of our Earth. The melting of subducted crustal plates, formation of new oceanic crust along Mid-oceanic ridges below the thick column of sea water, movement of crustal plates over the hot spot areas (upcoming convection cells) on the Earth’s surface are some of the types of Plate Tectonic movements causing such volcanoes.

Fig. 3.1: Natural Colour ALI Data of EO-1 Satellite showing Sinabung’s Volcanic Eruption and Pyroclastic Flow over Irrigated and Inhabited Areas (Image Source: http://earthobservatory.nasa.gov/IOTD/view.php?id=83080)

3.2.1.2 Earthquake Similar to the volcanic eruptions induced by the natural Plate Tectonic activities that are still going on the Earth’s surface, the Earthquakes are also resulted mostly due to the same reason. The Plate Tectonic movements over an area keeps accumulating pressure exerted over the Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Classification of Disasters crustal plate till the tolerance limits of rocks and then brakes along a fault plane and releases the accumulated pressure suddenly and thus the three types of seismic waves called ‘Primary, Secondary and Love waves’ are propagated in all directions (Figure 3.2).

Fig. 3.2: Propagation Patterns of Different Seismic Waves Source: www.geo.mtu.edu/UPSeis/waves.html

The areas will be worst affected by total collapse of buildings, where the intensity of these wave traverses are very high and the resultant disaster is known as Earthquake. Besides crustal plate breaks, certain other natural activities such as, volcanic explosion, huge rock fall or landslide, land subsidence, debris avalanche and snow avalanche, have also generated earthquake waves and the same have been recorded during their traverse with various intensities in several places. The location at which the seismic waves started propagating from the deep subsurface is known as Focus. The surface spot just above the Focus is known as Epicentre (Figures 3.3 a and b). 28



Figs. 3.3: (a) Aerial Photo showing San Andreas Fault and (b ) Block diagram showing break of crust and displacement along fault plane resulting into fast propagating Earthquake waves from origin point at the subsurface called ‘focus’ and the point directly above at the surface called ‘epicenter’.

From this epicenter point, the distances, the degree of damages to the habitations and the time taken to travel by different seismic waves are calculated and the power dissipation of seismic waves over distance will be estimated for different intensities of earthquakes for different places. Using this information, preparatory plans are drawn to mitigate future Earthquakes. Hence, most of the earthquakes are induced by the natural processes only. But, rarely earthquakes have also recorded due to massive constructions on weak zones, where lineaments and fault planes are weaker. This is being separately discussed in the subsequent paragraphs under the title “Natural Disasters Induced by Human Interventions”. 3.2.1.3 Landslide The Landslides are resulted due to variety of natural slope failure processes such as, weathering, soil erosion, rainfall, high speed winds, earthquake or minor tremor, lack of vegetal cover along hill slopes and hydrostatic imbalance within the hill slopes. Overall, the rainfall, cyclic and regular geomorphic processes and their agents which include mountain building processes can cause landslides naturally. Several types of landslides and related terminologies based on the type, speed and direction of sliding materials involved, are: soil creep, land/soil slip, translational slip, rock/ debris slump, rock/debris fall, etc. (Figures 3.4 a, b, c and d). Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Classification of Disasters

Fig. 3.4: Field Photographs Taken in Thirumala and Ooty Hill Slopes showing Different Types of Landslides: (a) Rock Fall, (b) Translational Slide, (c) Rockslide, (d) Landslip

3.2.1.4 Cyclone “Cyclone” is a derivative of the Greek word “Cyclos”; that means ‘coils of a snake’. Cyclone is one among the major climatic disaster caused due to the low pressure development over the Ocean surface naturally. The low pressure formed due to warming up of ocean water over tropics and subsequent hot moisture air formed close to the surface will start moving up due to its light density. As a result, low pressure surface is formed in that surface area. In order to equalize the pressure, little high dense air from the surrounding will move towards the low pressure area and again they get warmed up and raises above. During their raise, since there is very low temperature prevails at high altitudes, the hot moisture air gets cooled and condensed to form cloud and then at certain heights moved laterally either in anti-clock wise direction over the northern hemisphere or clockwise over the southern hemisphere because of the Coriolis effect (due to Earth’s self-rotation). This movement forms an eye at the center (Figures 3.5 a and b). Whenever it gains a rapid circulation then it is known as Cyclone. 30



Fig. 3.5: (a) Coriolis Effect (b) Satellite Image of Cyclone in Northern Hemisphere of Earth

3.2.1.5 Flood The natural rainstorm, heavy rain and cyclonic cloud burst brings huge quantum of surface water as flood and destroys the low lying area by washing out all the resources and properties all along its flow path and by inundation. Different types of floods classified based on the type of occurrence are: Flashflood, Dam failure flood, Overland flood, Coastal zone flood, Estuarine flood, Cloud burst flood, Snow melt flood and Lehar (Torrential mud flow), Single event flood, Multiple event flood and Seasonal flood. The satellite sensors designed in both visible, infrared and microwave bands to capture the flooded Earth’s surface brings all the details useful for mapping flood vulnerable areas, damage assessment and flood inducing parameters. The flood inundated areas appears with blue colour in False Colour Composite (FCC) image of Wide Field Scanner (WiFS) instrument fitted in Indian Remote sensing Satellite (IRS) is shown in Figures 3.6 a and b.

Fig. 3.6: IRS WIFS FCC Satellite Images of Parts of Coastal Odisha State showing (a) Crop Lands and Settlements before Cyclone and (b) Same Area Flooded after Cyclone Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Classification of Disasters 3.2.1.6 Soil Erosion Though soil erosion is a slow occurring natural disaster, the destructive impacts over a period of time have been highly recognized. The disastrous effects of soil erosion in terms of, (1) fertility loss and loss of soil itself in huge quantum, (2) land and forest degradation, (3) surface temperature increase and desertification, (4) reservoir siltation and pollution, (5) loss of storage capacity of reservoirs, (6) damages to the turbine blades of hydro-electric power dam by the eroded soil, (7) severely affecting the agricultural lands and settlement areas where wind activity is dominant by heaping up the eroded sand as dune and encroachment of sand dune. All these soil erosion derived destructions are noticed in many areas within Tamil Nadu. The Geoinfomatics technology is highly useful to map (1) areas of active soil erosion, (2) vulnerable areas of soil erosion and (3) inducing parameters of soil erosion. The erosion prone barren hill slopes and foot hills of parts of Western Ghats and the silted reservoirs and tanks seen clearly through the IRS 1A LISS-II satellite FCC images are shown in Figures 3.7 (a, b, c and d).

Fig. 3.7: (a), (b), (c) and (d) IRS 1A satellite FCC images of parts of Western Ghats and Vaigai River delta areas showing severe soil erosion along hill slopes and foot hills and siltation in reservoirs and lakes.

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Classification of Disasters IMTI 3.2.1.7 Tsunami One of the major threatening natural disasters along coastal areas is tsunami, the giant sea waves. Tsunami is caused due to several natural processes such as, submarine earthquakes due to plate tectonic movements, coastal landslides, submarine landslides, submarine volcanic explosions and snow avalanches along coast. But indirectly, the sudden temperature increase in the climate by developmental activities of human being can cause snow melting and glacial avalanche along vulnerable coast and may lead to tsunami.

3.2.2 Natural Disasters Induced by Human Interventions 3.2.2.1 Induced Earth Quake Reservoir induced seismicity and earthquakes, land subsidence based earthquakes, tremors and earthquakes due to improper heavy constructions in soft soil areas are known to us through media now-a-days. In vulnerable areas to seismicity, if the human development activities are made improperly without understanding the existing terrain conditions, then earthquakes will be induced. A best known example is the reservoir induced earthquake by Koyna dam located in Maharashtra state, which has been constructed over sensitive criss-crossing fault planes and lineaments. 3.2.2.2 Induced Landslide The sensitive toe removal along hill slopes in order to lay ghat roads have led to several landslides. For example, Marappalam landslide, uphill Ghat road side landslides all along Tirumala hills, and also along Ooty, Kodaikkanal and Himalayan ghat road sections have become regular disaster events, due to the improper human interventions with nature. 3.2.2.3 Induced Flood Inadequate and improper drainage networks and poor maintenance of river bunds, sewers and canal networks, tanks, and reservoirs from siltation, choking and defunct, improper storage and discharge of reservoir water, encroachment and blocking of tanks and lakes by agricultural activities Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Classification of Disasters and constructions may lead to breeched bunds and induced floods. The temporal Radar SAT data shown in Figure 3.8 clearly depicts the movement of flood water breeched out from a lake bund in the upstream side and inundated areas and period of inundation by flood water in Nepal.

Fig. 3.8: Temporal Radar SAT Data showing Lake Breaching at Shivganj Inundated Midhepura and Other Downstream Areas in Nepal

3.2.2.4 Induced Soil Erosion By nature, soil erosion will happen only in barren elevated areas as a weathering and transportation processes. But, the human intervention with nature such as deforestation along hill sides, slopes and also in plains, human made/induced forest fire, various unjustified infrastructure developmental activities and improper landuse are inducing soil erosion intensely. 3.2.2.5 Induced Drought Naturally, drought may happen in areas where high solar radiation is received, such as tropics, where there is a heavy draining of groundwater through leaky aquifers resulting into deeper groundwater levels, areas of tectonic emergence leading to deeper water level conditions, etc. But, due to the improper and unlimited exploitation of groundwater and blockage 34


Classification of Disasters IMTI of natural recharge of groundwater aquifers, atmospheric pollution by human developmental activities and intervening nature and the resultant increase in local area temperature can also cause drought.

3.2.3 Exclusive Human-made Disasters 3.2.3.1 Environmental Pollution Inappropriate disposal of both domestic and industrial wastes by human into potential lands and river systems led to severe pollution and permanent destruction of air, soil, surface water, groundwater and other important resources. Hence, it is high time to understand and stop our brutal activities which have led to environmental pollution. 3.2.3.2 Nuclear Accidents, Missile/Armed Attacks Terrorist attack or defense activities or war forces will handle missiles and arms for demolition. Further, certain accidents due to human error such as nuclear accidents will result countless disasters to the humans and the environment. 3.2.3.3 Stampedes Inappropriate access/entry and exit routes capable of handling the crowd and unexpected fear due to some accidents amongst a crowd may lead to stampede. In India, stampedes are mostly occurring during religious gatherings. In order to prevent stampede, it necessary to monitor and spot put the areas where pressure is building up in a dense moving crowd. For example, at Sabarimala temple area in Kerala, the areas such as dead ends, narrow roads, areas with -poor infrastructure facility, -no light, -no drinking water and -insufficient police force in crowding areas are identified as hazardous zones for the occurrence of human stampede. So, it is very important to consider all such situations and areas warranting primary attention need to be identified and proper prevention measures should be adopted at the earliest before such religious functions. It is also important to establish real time information and communication between emergency departments in preventing human stampede. Centre for Remote Sensing Bharathidasan University, Tiruchirappalli–620 023

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IMTI Disaster Vulnerable Area Mapping, Mitigation... CHAPTER – IV

Disaster Vulnerable Area Mapping, Mitigation, Damage Assessment and Management—Application of Geomatics Technology

D

isaster management involves several aspects comprising of disaster vulnerable area mapping, proper understanding of type and degree of causative parameters involved, mitigation or prevention planning, assessing damages caused by the disaster and rehabilitation. It is important to determine the disaster inducing parameters based on natural processes and anthropogenic interventions. Recent researchers have attempted to delineate the ratio of combination of these two types of inducing parameters and thus higher accuracy, suitability and pragmatism could be achieved in planning for mitigation or even it is also possible to eradicate the vulnerability of an area from disasters. Having a variety of terrain combinations with 3 major types of climates, India is also prone for several natural disasters such as, earthquakes, landslides, cyclones, tsunamis, floods, etc. Geomatics technology comprising Aerial and Satellite Remote Sensing, Digital Image Processing, Digital Cartography, GIS and GPS, has emerged as a powerful tool in various earth resources surveys, ecosystems/environmental appraisals and also natural disaster zonation mapping, mitigation and management. While, the aircraft based B/W panchromatic pictures have their own credentials in displaying the Earth system features in their physiographic perspectives 3 dimensionally, the satellite based Remote Sensing has attention deserving credentials owing to their synoptivity, multi spectral photo captivity and repetitive imaging capabilities of the terrestrial surface. 36


Disaster Vulnerable Area Mapping, Mitigation... IMTI Besides the other virtues, the repetitive coverage of the satellites has special advantages in assessing the natural disasters. The image processing techniques are specially empowered with preferential display of various Earth surface features. While GPS can offer precise help in geo positioning, the digital cartography can pictorially bring out spatial maps on various aspects of Earth surface features including the disasters. The GIS is vested with a lot of credentials owing to their capabilities of: • Storing huge volume of geospatial data on various themes. • Preferential display of thematic maps. • Displaying the data as charts, histograms, tables, contours, etc. • Displaying the map data as Digital elevation models, shaded relief out puts, line site maps, visibility maps, etc. • Various statistical options like addition, subtraction, multiplication, division, etc. • Corridoring, buffering, networking, spatial decision support system, etc. Owing to such advanced virtues, the geomatics technology, has gained unparallel position in various disaster vulnerability mapping, risk analysis, mitigation, management, etc. (Ramasamy et al.., 2004) This chapter is dealt about the application of Geomatics technology for making disaster management plans during crisis through the newer methodologies derived out of research studies conducted in nationally reputed institutions and published in leading journals.

4.1 Earthquake The previous records on earthquakes form as one of the important database for delineating susceptible zones for seismicities, i.e., low magnitude tremors (