Floods in Bangladesh: history, dynamics and rethinking the role of the Himalayas

Floods in Bangladesh: History, dynamics and rethinking the role of the Himalayas......Page 5
Contents......Page 7
Figures......Page 9
Tables......Page 16
Boxes......Page 19
Preface......Page 21
The core institutions (Table P.1)......Page 22
The key institutions for data collection (Table P.2)......Page 25
Partner institutions and resource persons for information exchange (Table P.3)......Page 26
Acknowledgements......Page 32
1.1. The theory of Himalayan degradation: Traditional understanding and emerging doubts......Page 33
1.2. The highlands - and their lowland linkages: Twelve years of research on Himalayan ecology......Page 35
1.3. The lowlands - and their highland linkages: Research on ‘‘Floods in Bangladesh’’......Page 36
1.4. The structure of the book......Page 41
1.5. An important contribution to the International Year of Mountains......Page 42
2.1. Bangladesh: An unusual country profile (see front cover)......Page 43
2.2. Mechanisms of the monsoon circulation......Page 49
2.2.1. The monsoon and its formation......Page 50
2.2.2. The cycle of the Indian summer monsoon......Page 53
2.2.4. Precipitation patterns in the Ganga-Brahmaputra-Meghna basin......Page 54
2.2.5. River discharge patterns in the Ganga-Brahmaputra-Meghna basin......Page 57
2.3.1. The main physiographical units......Page 59
2.3.3. The extent and range of flooding......Page 62
2.3.4. The depth, duration and timing of flooding......Page 66
2.3.5. The causes of flooding......Page 69
3.1. Rainfall......Page 71
3.2. Discharge......Page 77
3.4. Groundwater......Page 81
3.6. Reflection on the data situation......Page 83
4.1. Introduction to the issue......Page 84
4.2.1. A brief look at the longer-term geological history......Page 88
4.2.2. The last 20,000 years......Page 90
4.3.1. Historical floods in the Ganga and Brahmaputra catchments......Page 95
4.3.2. Specific flood events in Bengal in the eighteenth and nineteenth centuries......Page 97
4.4. The twentieth century......Page 101
4.4.1. Floods in Bangladesh, 1890-2004......Page 102
4.4.2. Flood history in the lowlands of the Ganga and Brahmaputra, 1954-1994......Page 110
4.4.3. Rainfall trends in the Ganga-Brahmaputra-Meghna basin in the twentieth century......Page 118
4.4.4. Discharge trends in the Ganga-Brahmaputra-Meghna basin in the twentieth century......Page 123
4.4.5. Increasing vulnerability: The socio-economic dimension......Page 131
4.5. The main findings......Page 138
5.1. Introduction......Page 140
5.2.1. Delimitation of subcatchments (step 1)......Page 144
5.2.2. Definition of inner-annual time periods (step 2)......Page 146
5.2.3. Calculation of areal precipitation and precipitation volume for the 13 subcatchments (step 3)......Page 148
5.2.4. Potential runoff (step 4)......Page 153
5.2.5. The relevance of the potential runoff for Bangladesh (step 5)......Page 169
5.2.6. Gaining experience with the newly introduced variables......Page 175
5.3. Introduction to the case studies......Page 179
5.4. 1906: A ‘‘flood year’’......Page 182
5.5. 1910: A ‘‘flood year’’......Page 186
5.6. 1922: A ‘‘flood year’’......Page 191
5.7. 1955: A ‘‘flood year’’ for Bangladesh......Page 195
5.8. 1974: A ‘‘flood year’’ for Bangladesh......Page 197
5.9. 1987: A ‘‘flood year’’ for Bangladesh......Page 204
5.10. 1988: A ‘‘flood year’’ for Bangladesh......Page 209
5.11. 1998: A ‘‘flood year’’ for Bangladesh......Page 215
5.12. 1923: A ‘‘dry year’’......Page 220
5.13. 1978: A ‘‘dry year’’ for Bangladesh......Page 223
5.14. 1993: An ‘‘average flood year’’ for Bangladesh......Page 227
5.15. The application of remote sensing techniques for the analysis of floods......Page 229
5.15.1. The database......Page 230
5.15.2. Classification of clouds and image-processing......Page 231
5.15.3. The test period 28 July-20 August 1987 (24 days)......Page 233
5.15.4. The test period 1-20 July 1988 (20 days)......Page 236
5.15.5. The test period 20 August-5 September 1988 (17 days)......Page 238
5.15.6. Summary......Page 241
5.16. The 11 case studies: A comparison......Page 242
5.16.1. Mid-August - a critical time for the development of large floods......Page 243
5.16.2. The hydro-meteorological patterns in the Ganga-Brahmaputra-Meghna system: A differentiated picture......Page 245
5.16.4. Synchronization of discharge peaks - a very important trigger for flood generation......Page 248
Notes......Page 253
The 1906 flood situation at a glance......Page 254
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.2, Figure 5.1)......Page 256
Daily rainfall (Figure 5A.3)......Page 261
Summary......Page 265
The 1910 flood situation at a glance......Page 268
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.6, Figure 5.1)......Page 271
Daily rainfall (Figure 5A.7)......Page 272
Daily water level (Figure 5A.8)......Page 274
Summary......Page 276
The 1922 flood situation at a glance......Page 277
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.10, Figure 5.1)......Page 280
Daily rainfall (Figure 5A.11)......Page 283
Daily water level (Figure 5A.12)......Page 284
Summary......Page 285
The 1955 flood situation at a glance......Page 286
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.14, Figure 5.1)......Page 288
Daily rainfall (Figure 5A.16)......Page 290
Summary......Page 293
The 1974 flood situation at a glance......Page 295
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.19, Figure 5.1)......Page 297
Monthly discharge (Figure 5A.20)......Page 299
Daily rainfall (Figure 5A.21)......Page 301
Daily discharge (Figure 5A.22)......Page 303
Groundwater (Figure 5A.23)......Page 305
Summary......Page 308
The 1987 flood situation at a glance......Page 309
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.25, Figure 5.1)......Page 311
Monthly discharge (Figure 5A.26)......Page 314
Daily rainfall (Figure 5A.27)......Page 316
Daily discharge (Figures 5A.28 and 5A.29)......Page 319
Groundwater (Figure 5A.30)......Page 323
Summary......Page 325
The 1988 flood situation at a glance......Page 326
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.32, Figure 5.1)......Page 329
Monthly discharge (Figure 5A.33)......Page 331
Daily rainfall (Figure 5A.34)......Page 333
Daily discharge (Figures 5A.35 and 5A.36)......Page 337
Tidal effects (Figure 5A.38)......Page 341
Summary......Page 344
The 1998 flood situation at a glance......Page 345
Monthly rainfall (Figure 5A.40, Table 5A.7)......Page 351
Daily rainfall (Figure 5A.41)......Page 353
Daily water level......Page 355
Summary......Page 361
The 1923 drought and flood situation at a glance......Page 362
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.44, Figure 5.1)......Page 363
Daily water level (Figure 5A.46)......Page 365
The 1978 drought and flood situation at a glance......Page 368
Hydrological contributions from the different subcatchments and their relevance (Figure 5A.47, Figure 5.1)......Page 369
Monthly discharge (Figure 5A.48)......Page 371
Daily discharge (Figure 5A.50)......Page 374
The flooding in the Indian Ganga basin......Page 376
Summary......Page 380
The 1993 flood situation......Page 382
Monthly rainfall (Figure 5A.53)......Page 383
Daily rainfall......Page 384
Daily discharge......Page 386
Summary......Page 389
6.1. The data situation......Page 391
6.2. The geological and historical dimension......Page 393
6.3.1. Mass movements......Page 395
6.3.2. Soil erosion......Page 398
6.4.1. Shifting river courses and lateral erosion......Page 406
6.4.2. Sediment load and sedimentation......Page 409
7.1. Introduction: Why should the human dimension be considered in a flood research project?......Page 421
7.2. The fieldwork: How was the human dimension approached in this flood research project?......Page 422
7.3.1. Flood perceptions of the affected rural population......Page 425
7.3.2. Flood perceptions of politicians and engineers......Page 428
7.3.3. Floods in the perception of the international media......Page 429
7.4. Flood events: Adaptation and mitigation strategies of the rural population......Page 431
7.4.2. Agriculture and crops......Page 432
7.4.3. Daily life......Page 434
7.4.4. Transportation......Page 435
7.5.1. Perceptions and experiences......Page 436
7.5.2. Coping strategies......Page 438
7.6.1. Approaches before 1989......Page 442
7.6.2. The Flood Action Plan (FAP), 1989-1995......Page 444
7.6.3. 1995 and beyond......Page 445
7.7. The approach of the rural population to flood control and flood protection......Page 450
8.1. The history of floods in Bangladesh......Page 455
8.2. The dynamics of floods in Bangladesh......Page 456
8.2.1. The regional dimension......Page 457
8.2.3. The process-oriented dimension......Page 458
8.3. Rethinking the role of the Himalayas......Page 459
8.4. Natural disasters and their impacts - A brief comparison......Page 460
8.5. Different perceptions, integrated approaches and common solutions......Page 462
8.6. A short comparison with recent processes in three floodplains of three continents......Page 463
8.7. A brief outlook: Research, development and cooperation......Page 466
8.7.1. Research and cooperation......Page 467
8.7.2. Development and cooperation......Page 468
References......Page 470
Index......Page 492