Impacts of Global Change on the Hydrological Cycle in West and Northwest Africa

Cover......Page 1
Impacts of Global Change on the Hydrological Cycle in West and Northwest Africa......Page 4
9783642129568......Page 5
Foreword......Page 6
Acknowledgements......Page 8
Preface......Page 10
Content......Page 12
Part I Fundamentals and process understanding......Page 19
1 Introduction......Page 22
P. Speth and A. H. Fink......Page 23
Past and present situation......Page 24
Regionalization of climate projections......Page 25
Choice of catchments......Page 26
Options for a sustainable development......Page 27
Outline of the book......Page 28
2 Impacts of Global Change......Page 30
I-2 Impacts of Global Change......Page 31
References......Page 32
Abstract......Page 33
References......Page 39
Abstract......Page 41
References......Page 45
3. Regional geography of West and Northwest Africa: An introduction......Page 48
I-3 Regional geography of West and Northwest Africa: An introduction......Page 49
I-3.1.1 The Ouémé basin (southeastern edge of WAC)......Page 52
I-3.1.2 The Drâa basin (northwestern edge of WAC)......Page 55
I-3.2.1 Geomorphological provinces of Benin......Page 57
I-3.2.2 Geomorphological provinces of Southern Morocco......Page 59
I-3.3 Soils......Page 63
I-3.3.1 Soils of Benin......Page 66
I-3.3.2 Soils in the Drâa valley of Southern Morocco......Page 67
I-3.4.1 Subtropical climate of Northwest Africa......Page 71
I-3.4.2 Tropical climate of West Africa......Page 73
I-3.5 Hydrology......Page 77
I-3.5.1 Ouémé basin......Page 79
I-3.5.2 Drâa basin......Page 80
I-3.6.1 Upper Guinean rain forest......Page 83
I-3.6.3 Azonal vegetation types......Page 84
I-3.6.4 Mediterranean/Sahara transitional zone in Morocco......Page 85
3.7.1 Colonial period......Page 87
I-3.7.2 Postcolonial era......Page 88
I-3.8.1 West and Northwest Africa......Page 91
I-3.8.2 Benin......Page 93
I-3.8.3 Morocco......Page 96
I-3.9 Economy and infrastructure......Page 99
I-3.9.1 Benin......Page 100
I-3.9.2 Morocco......Page 101
I-3.10.1 Crossing the Tropic of Cancer from the Mediterranean coastal lands to tropical Africa......Page 105
I-3.10.2 Benin......Page 107
I-3.10.3 Morocco......Page 108
I-3.10.4 Agricultural systems as concentrators and dilutors of resources......Page 109
I-3.11.1 West Africa......Page 111
I-3.11.2 Northwest Africa......Page 114
I-3.12 References for chapter I-3......Page 115
4 Measurement concepts......Page 122
I-4 Measurement concepts......Page 123
I-4.1.1 Introduction......Page 125
I-4.1.2 Meteorological measurements......Page 127
I-4.1.3 Hydrological measurements......Page 129
References......Page 130
I-4.2.1 Introduction......Page 131
I-4.2.2 Meteorological observations in Benin used for data products......Page 132
I-4.2.3 Data products and monitoring......Page 135
References......Page 138
I-4.3.1 Introduction......Page 139
I-4.3.2 Meteorological measurements at the test sites......Page 141
I-4.3.3 Hydrological and other measurements......Page 147
References......Page 148
5 Atmosphere......Page 150
I-5 Atmosphere......Page 151
I-5.1.1 Introduction......Page 152
I-5.1.2 Air masses, convergence zones, and wind systems......Page 153
Atmospheric circulation and disturbances......Page 154
Rainfall types......Page 156
I-5.1.4 Interannual-to-decadal rainfall variability......Page 159
I-5.1.5 The role of sea surface temperatures in West African rainfall......Page 161
I-5.1.6 The role of greenhouse gases and aerosols in West African rainfall......Page 163
References......Page 164
I-5.2.1 Introduction......Page 167
Climatic observations in Morocco......Page 168
Rainfall bearing weather situations and global climate variability......Page 169
I-5.2.3 Summer precipitation and convective density currents......Page 176
I-5.2.4 Conclusions......Page 178
References......Page 179
6 Continental hydrosphere......Page 182
I-6 Continental hydrosphere......Page 183
References......Page 184
Abstract......Page 185
I-6.1.2 Hydrological processes at the local scale......Page 186
Runoff generation processes......Page 187
Physically based hydrological modeling......Page 190
Large scale pattern of land use and hydrological processes......Page 193
Regional hydrological modeling......Page 195
Calibration and Validation......Page 196
Simulated water balance and spatial pattern......Page 199
I-6.1.4 Soil degradation and soil erosion......Page 202
Soils in the Upper Ouémé catchment and their susceptibility to soil degradation......Page 203
Modeling soil erosion at the regional scale......Page 204
Model calibration......Page 205
Model validation......Page 208
Discussion of model results......Page 210
References......Page 212
Abstract......Page 215
I-6.2.1 Introduction......Page 216
I-6.2.2 Seasonal predictions of snowmelt in the High Atlas mountains for reservoir management......Page 218
Snow-related processes at the local scale......Page 219
Simulation of snow dynamics at the local scale......Page 220
Remote sensing of snow......Page 222
From the local to the regional scale......Page 224
Hydrological processes at the local scale......Page 227
Quantification of hydrological processes at the regional scale......Page 229
Simulation of water fluxes: model development......Page 232
Model setup......Page 235
Model validation......Page 237
Model results......Page 239
Discussion......Page 240
I-6.2.4 Sub-surface flow in the Middle Drâa basin......Page 241
Aquifer setting......Page 242
Concept of the regional aquifer system......Page 244
Model concept and parameterization......Page 245
Model results......Page 246
I-6.2.5 Soil salinity: Measurements, processes, and simulations......Page 248
I-6.2.6 Soil erosion by water: Processes and simulations......Page 254
I-6.2.7 Conclusions......Page 264
References......Page 266
7 Biosphere......Page 272
I-7 Biosphere......Page 273
Abstract......Page 274
I-7.1.2 Characterizing vegetation cover in Benin using NDVI calculations from remote sensing data......Page 275
Fire regime in Benin......Page 277
Bush fire drivers......Page 279
I-7.1.4 Assessing natural vegetation and land use distribution in Central Benin......Page 282
Data and methods......Page 283
Satellite image classification......Page 285
I-7.1.5 Changing land use: Hot spots of current land use andland cover changes......Page 286
I-7.1.6 Conclusions......Page 288
References......Page 289
I-7.2.1 Introduction......Page 291
I-7.2.3 Plant diversity along gradients......Page 292
I-7.2.4 Resilience of arid and semi-arid ecosystems......Page 294
I-7.2.5 Rehabilitation pace......Page 296
I-7.2.6 Conclusions......Page 297
References......Page 298
8 Anthroposphere......Page 300
I-8 Anthroposphere......Page 301
I-8.1 The societal framework of water management and strategies of livelihood security......Page 302
Abstract......Page 303
The polygynous family......Page 304
Households and residential units......Page 305
I-8.1.1.3 Income and the impact of occultism......Page 307
I-8.1.1.4 Livelihood strategies and land use......Page 308
The risk of cotton production......Page 310
Gift exchange as a risk-minimizing strategy......Page 311
Strategies of Beninese water users to satisfy water demand......Page 312
Limitations and constraints of an optimal water supply in Benin......Page 318
I-8.1.1.7 Conclusions......Page 319
References......Page 320
I-8.1.2.1 Introduction......Page 322
I-8.1.2.2 Ethnic, social, and cultural background......Page 323
Urbanization......Page 324
Labor migration......Page 326
Traditional and state institutions – parallel structures and conflicting decisions......Page 328
I-8.1.2.5 Conclusions......Page 329
References......Page 331
I-8.2 Economics of agriculture and water use......Page 332
I-8.2.1.1 Introduction......Page 333
I-8.2.1.2 Land use, agriculture, and food security......Page 334
I-8.2.1.3 Simulation of cropland use trends in Benin......Page 337
I-8.2.1.4 The role of livestock husbandry in the water cycle......Page 341
I-8.2.1.5 Conclusions......Page 344
References......Page 345
I-8.2.2.1 Introduction......Page 346
I-8.2.2.2 The importance of water use for economic development in Morocco......Page 347
I-8.2.2.3 Traditional water management in the Drâa oases......Page 348
I-8.2.2.4 The push for modernization......Page 349
I-8.2.2.5 The resilience of traditional water institutions......Page 350
I-8.2.2.6 Agricultural production and available water resources......Page 351
I-8.2.2.7 The hydro-economic simulation model MIVAD......Page 353
I-8.2.2.8 Conclusions......Page 356
References (I-8.2.2)......Page 358
9 Summary......Page 360
The Ouémé catchment......Page 361
The Drâa catchment......Page 362
Database......Page 363
Process understanding and modeling approaches......Page 364
Part II Future projections and decision support......Page 367
1 Introduction: The IMPETUS method......Page 370
II-1 Introduction: The IMPETUS method......Page 371
Problem clusters and models......Page 373
Scenarios (for details see chap. II-3)......Page 374
Stakeholder dialogue and capacity building......Page 375
2 The IMPETUS Spatial Decision Support Systems......Page 378
II-2.1 Introduction......Page 379
II-2.2 Spatial Decision Support Systems......Page 380
Information Systems (IS)......Page 381
Compilation of requirements......Page 382
Organizational aspect......Page 383
Societal aspect......Page 384
Scientific aspect......Page 385
II-2.3 The Scientific Model Integration pipeLine Engine Framework......Page 386
Structure of the SMILE framework......Page 387
GUI: Graphical User Interface......Page 388
Configuration XML......Page 389
II-2.4.1 Spatial Decision Support System PEDRO......Page 390
Application......Page 391
Results......Page 394
II-2.4.2 IWEGS......Page 395
Application......Page 396
Application......Page 399
Discussion......Page 402
Application......Page 403
II-2.5 Conclusions......Page 406
References......Page 408
3 Scenarios......Page 412
II-3 Scenarios......Page 413
II-3.1.1 General definition of scenarios......Page 414
II-3.1.2 Definition of alternative scenarios and sub-regions within IMPETUS......Page 415
II-3.1.3 Intervention scenarios......Page 416
References......Page 417
II-3.2.1 Introduction......Page 419
II-3.2.2 The hierarchy of dynamical models......Page 420
II-3.2.3 Construction of alternative climate scenarios......Page 421
II-3.2.4 Characteristic tables and storylines for Benin and Morocco......Page 422
Storyline for scenario (a) in Benin: Climate model projections......Page 423
Storyline for scenario (b) in Benin: Process understanding......Page 424
Storyline for scenario (c) in Benin: Persistence of recently observed trends (business as usual)......Page 425
Storyline for scenario (a) in Morocco: Displacement of the NAO......Page 426
Storyline for scenario (c) in Morocco: Trend extrapolation......Page 427
II-3.2.5 Dynamical downscaling, model bias correction, and the Weather Generator (WEGE): An example for Benin......Page 428
Post-processing of climate model data......Page 429
II-3.2.6 The statistical downscaling approach used in the High Atlas region......Page 433
Identification of Circulation Weather Types (CWTs)......Page 436
II-3.2.8 Summary of the model-based methods of regionalization of climate information for climate scenarios......Page 440
References......Page 441
II-3.3.1 Introduction......Page 443
Storyline for socio-economic scenario B1: Economic growth and consolidationof decentralization......Page 446
Storyline for socio-economic scenario B2: Economic stagnation and institutional insecurity......Page 448
Storyline for socio-economic scenario B3: Business as usual......Page 450
II-3.3.3 IMPETUS socio-economic scenarios for Morocco......Page 451
Storyline for socio-economic scenario M1: Marginalization - non-support of the Drâa region......Page 452
Storyline for socio-economic scenario M2: Rural development in the Drâa region through regional funds......Page 454
Storyline for socio-economic scenario M3: Business as usual......Page 456
References......Page 458
The demographic dimension of environmental change......Page 459
Population projections......Page 460
Methodological approach......Page 461
Conclusions......Page 464
References......Page 465
4 Impacts of Global Change in Benin......Page 468
II-4 Impacts of Global Change in Benin......Page 469
II-4.1.1 Introduction......Page 471
Adaptation of cropping systems......Page 473
Changes in fallow management......Page 474
The productive potential of bas-fonds......Page 476
Conclusions......Page 477
Crop productivity in traditional cropping systems......Page 479
Effects of Climate Change on crop productivity......Page 483
II-4.1.4 Economic scenarios for food markets and land use......Page 486
II-4.1.5 Consequences of deforestation for livestock management......Page 488
II-4.1.6. Increased use of mineral fertilizer: Higher food security?......Page 490
Fertilizer policy in Benin......Page 491
Endogenizing the use of fertilizer in BenIMPACT......Page 493
Scenario design......Page 495
Selected results......Page 496
II-4.1.7 Conclusions......Page 499
References......Page 500
Abstract......Page 501
II-4.2.2 Scenarios of land use change and Climate Change: Impact on hydrology and water availability......Page 502
Land use scenarios......Page 503
Climate scenarios......Page 506
II-4.2.3 Soil erosion by water in the Upper Ouémé catchment considering land use change and Climate Change......Page 511
Results of scenario analysis......Page 512
Applying WEAP to the Ouémé catchment......Page 515
Water demand scenarios......Page 516
Balancing water demand and supply – WEAP modeling results......Page 518
Water supply security of the Ouémé-Bonou catchment: Interpretation of the WEAP modeling results......Page 520
II-4.2.5 Spatial Decision Support Systems for water-related issues: BenHydro and BenEau......Page 522
II-4.2.6 Conclusions......Page 525
References......Page 526
Abstract......Page 529
II-4.3.1 Introduction......Page 530
II-4.3.2 Concepts in land system research......Page 532
Definitions and some methodological aspects......Page 533
Causes and explanations......Page 535
Modeling approaches......Page 536
Remote sensing data......Page 537
Classification of land use and land cover of the Upper Ouémé catchment......Page 538
Parameterization......Page 539
Model results......Page 540
Definition of scenarios and parameters for LUMIS......Page 543
(B1) Economic growth scenario......Page 544
(B2) Economic stagnation scenario......Page 545
(B5) Intervention scenario......Page 546
II-4.3.6 Conclusions......Page 547
References......Page 548
II-4.4.1 Introduction......Page 553
II-4.4.2 Land tenure in the context of national policies......Page 554
II-4.4.3 Water management in times of decentralization......Page 558
II-4.4.4 LISUOC (Livelihood Security in the Upper Ouémé Catchment): An information system for the decentralized communities......Page 561
Module 2: Water management and institutional change......Page 562
II-4.4.5 Conclusions......Page 563
References......Page 564
II-4.5.1 Introduction......Page 567
Malaria modeling......Page 568
Present-day malaria simulations......Page 569
Malaria projections (2001-2050)......Page 570
Water quality monitoring......Page 572
Viral and bacteriological water quality in drinking water sources......Page 574
Information system SIQeau......Page 576
II-4.5.4 Conclusions......Page 577
References......Page 578
5 Impacts of Global Change in Southern Morocco......Page 580
II-5 Impacts of Global Change in Southern Morocco......Page 581
Abstract......Page 583
II-5.1.2 Crop management in oasis agriculture in the Drâa basin......Page 584
Crop management in the desert oases of the Drâa valley......Page 585
Agricultural production in the mountain oases......Page 588
Climate Change scenarios using the MIVAD modeling approach......Page 589
Impact of Climate Change on modeling results......Page 590
II 5.1.4 Pastoralists’ resource management and livelihood securityin the Drâa region......Page 595
Material and Methods......Page 596
Results......Page 597
Traditional and modern management strategies......Page 598
Coping with drought......Page 599
Modern range management strategies: Implications for livelihood security, and resilience......Page 600
Background and Methods......Page 601
Results......Page 602
II 5.1.6 Conclusions......Page 606
References......Page 607
II-5.2.1 Introduction......Page 609
II-5.2.2 Seasonal snowmelt runoff forecast for the management of the Mansour Eddahbi Reservoir......Page 610
Results of scenario modeling with PRO-RES......Page 612
II-5.2.3 Global change effects on hydrological processes in the Upper Drâa catchment......Page 614
Scenario results......Page 615
Hydraa: A Spatial Decision Support System for water-related issues......Page 618
The IWEGS SDSS......Page 619
Climatic scenarios......Page 620
Socio-economic scenarios......Page 621
Results of climatic scenarios......Page 622
Results of the socio-economic scenarios......Page 624
II-5.2.5 Conclusions......Page 626
References......Page 627
II-5.3.1 Introduction......Page 629
II-5.3.2 Too much rain: The case of severe rainfall events......Page 630
The effects of severe rainfall: Floods and erosion......Page 631
Mitigating floods and erosion: The effects of pastoral land management......Page 634
The combined impact of climate and land use change on soil erosion......Page 636
II-5.3.3 Too little rain: The case of meteorological drought......Page 638
Effects of meteorological drought: Natural resource scarcity......Page 639
Mitigating drought: The role of ecological buffers......Page 640
Searching fodder resource reliability......Page 642
Investments into the ecological buffer of the vegetation......Page 644
Functional connections among drought, flood, and erosion......Page 645
II-5.3.4 Agricultural strategies to cope with unpredictable water resources......Page 646
How to mitigate extreme events in the Drâa catchment?......Page 647
References......Page 648
II-5.4.1 International and national migration......Page 651
Migration on a local scale......Page 653
Labor migrant destinations......Page 654
Remittances from national and international migration......Page 656
Pastoral management systems – the practice of transhumance......Page 657
The importance of local knowledge for decision-making processes......Page 659
II-5.4.3 Conclusions......Page 662
References......Page 663
6 Summary and conclusions......Page 666
Summary of some results for Benin......Page 667
Society......Page 668
Livelihood security and society......Page 669
Hydrology......Page 670
Conclusions......Page 671
Authors......Page 673
Acronyms......Page 678
Index......Page 685