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CONTENTS
TITLE PAGE ... i
APPROVAL OF THE VIVA-VOCE BOARD ... ii
CERTIFICATE ... iii
ACKNOWLEDGEMENTS... iv
LIST OF SYMBOLS AND ABBREVIATIONS ...v
ABSTRACT... vii
DECLARATION ... viii
CHAPTER 1 ...1
1.1 INTRODUCTION ...1
1.2 BACKGROUND OF THE STUDY ...1
1.3 OBJECTIVES AND SCOPE OF WORK ...4
1.4 CONTRIBUTION OF THE THESIS ...5
1.5 STRUCTURE OF THE THESIS...7
CHAPTER 2 ...9
2.1 INTRODUCTION ...9
2.2 HYDRODYNAMIC MODELING...9
2.2.1 River Hydraulics ...9
2.2.2 Hydrodynamic Modeling with HEC-RAS Software ...10
2.2.3 Hydrodynamic Modeling with Other Software ...12
2.3 FLOOD FREQUENCY ANALYSIS ...14
2.4 FLOOD HAZARD ASSESSMENT...19
CHAPTER 3 ...23
3.1 INTRODUCTION ...23
3.2 DIGITAL ELEVATION MODEL ...23
3.3 HYDRODYNAMIC MODEL...24
3.4 FLOOD FREQUENCY ANALYSIS ...27
3.4.1 L- Moments...28
3.4.2 Probability Weighted Moments and Their Estimators...28
3.4.3 Screening of the Data with Discordancy Measure...31
3.4.4 Identification of Homogeneous Regions using Heterogeneity Measure .32 3.4.5 Choice of Regional Frequency Distribution ...34
3.4.5.1 L-moment Ratio Diagram...36
3.4.5.2 Goodness-of-fit Measure ...36
3.5 FLOODPLAIN MAPPING AND DAMAGE ASSESSMENT...38
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3.5.1 Flood Inundation Map...38
3.5.2 Flood Hazard Map ...38
3.6 LAND USE AND LAND COVER CLASSIFICATION ...39
3.7 THEMATIC CLASSIFICATION ...40
3.8 CLASSIFICATION ERROR MATRIX...41
3.9 EVALUATING CLASSIFICATION ERROR MATRIX...41
CHAPTER 4 ...43
4.1 INTRODUCTION ...43
4.2 DESCRIPTION OF THE STUDY AREA ...44
4.2.1 Administrative Blocks of the Study Area ...45
4.3 DIGITAL ELEVATION MODEL (DEM) OF THE STUDY AREA...46
4.3.1 Development of DEM and Ortho-Image from CARTOSAT-1 Data...47
4.3.2 Development of Elevation Contour from DEM...50
CHAPTER 5 ...55
5.1 INTRODUCTION ...55
5.2 HYDRODYNAMIC MODELING OF THE SUBERNAREKHA RIVER 55 5.2.1 Development of Channel Network in GIS Platform...56
5.2.2 Extraction of River Cross Sections from DEM ...57
5.2.3 Adjustment of Hydrodynamic Model Parameters ...60
5.2.4 Boundary Conditions of the Model...62
5.2.5 Setting of Simulation Parameters...63
5.3 DISCHARGE AND WATER LEVEL DATA FROM 1985 TO 2005 ...63
5.4 CALIBRATION AND VALIDATION OF THE MODEL...73
5.5 HYDRODYNAMIC MODEL OF THE FLOOD AFFECTED YEAR 1985 74 5.5.1 Results of Water Level and Discharge...74
5.5.2 Performance of the Hydrodynamic Model ...78
5.6 HYDRODYNAMIC MODEL OF THE FLOOD AFFECTED YEAR 1988 78 5.6.1 Results of Water Level and Discharge...78
5.6.2 Performance of the Hydrodynamic Model ...81
5.7 HYDRODYNAMIC MODEL OF THE FLOOD AFFECTED YEAR 1997 82 5.7.1 Results of Water Level and Discharge...82
5.7.2 Performance of the Hydrodynamic Model ...86
CHAPTER 6 ...87
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6.1 INTRODUCTION ...87
6.2 SCREENING OF THE DATA USING DISCORDANCY MEASURE...87
6.3 IDENTIFICATION OF HOMOGENEOUS REGIONS BY HETEROGENEITY TEST...89
6.4 CHOICE OF REGIONAL FREQUENCY DISTRIBUTION ...90
6.4.1 L-moment Ratio Diagram...91
6.4.2 Goodness-of-fit Measure ...92
6.5 COMPOSITE MODEL FOR REGIONAL FREQUENCY DISTRIBUTION 95 6.5.1 Development of Composite Model using Neural Networks...95
6.5.2 Simulation Study for Evaluating Composite Model Performance ...98
6.6 REGIONAL FLOOD FREQUENCY RELATIONSHIP ...100
CHAPTER 7 ...105
7.1 INTRODUCTION ...105
7.2 LAND USE AND LAND COVER CLASSIFICATION ...105
7.2.1 Thematic Classification ...105
7.3 ESTIMATION OF WATER LEVELS FROM RASTER DATA ...108
7.4 FLOOD INUNDATION MAPPING AND DAMAGE ASSESSMENT ..109
7.4.1 Flood Inundation Mapping and Damage Assessment due to Flood Affected Year 1985...109
7.4.2 Flood Inundation Mapping and Damage Assessment due to Flood Affected Year 1988...110
7.4.3 Flood Inundation Mapping and Damage Assessment due to Flood Affected Year 1997...111
7.5 FLOOD HAZARD ASSESSMENT OF DIFFERENT RETURN PERIODS 112 7.5.1 Bump Function for Estimating Flood Peak for the Years 1985 to 2005115 7.5.2 Classification of Hydrographs ...118
7.5.3 Flood Hazard Mapping and Assessment for 10 Years Return Period ..123
7.5.4 Flood Hazard Mapping and Assessment for 25 Years Return Period ...129
7.5.5 Flood Hazard Mapping and Assessment for 50 Years Return Period ...132
7.5.6 Flood Hazard Mapping and Assessment for 100 Years Return Period .135 7.6 COMPARISON OF FLOOD HAZARDS BETWEEN RETURN PERIODS 137 CHAPTER 8 ...139
8.1 INTRODUCTION ...139
8.2 SUMMARY...139
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8.3 OBSERVATIONS AND CONCLUSIONS ...141
8.3.1 Observations ...141
8.3.2 Conclusions...144
8.4 RECOMMENDATIONS AND LIMITATIONS ...144
8.5 SCOPE FOR FUTURE RESEARCH...145
REFERENCES ...147
Appendix - A...155
Appendix - B...157
Appendix – C ...162
Appendix - D...167
