Mankind and Deserts 3

Foreword ix
Yvette Dewolf

Introduction: Aeolian Dynamics and Processes xiii
Yann Callot

Chapter 1. Aeolian Landforms in Deserts 1
Yann Callot

1.1. Forms and surface states 1

1.2. Ablation forms 2

1.2.1. Desert pavement 2

1.2.2. Coherent rock landforms 5

1.2.3. A mixed ablation shape: hydro-aeolian depressions 15

1.3. Accumulation formations 16

1.3.1. Amorphous accumulations 18

1.3.2. Smaller aeolian formations 21

1.3.3. Sandy accumulations without sharp crests 27

1.3.4. Dunes with sharp crests 28

1.3.5. Combinations of sifs 36

1.3.6. Non-sandy aeolian accumulations 43

1.4. Aeolian systems 47

1.4.1. Initial combinations: arrow, elb and draa 48

1.4.2. Interdune spaces 50

1.4.3. Polygenic formations 52

1.5. Ergs, the most complex aeolian systems 60

1.5.1. Definition 60

1.5.2. The formation of ergs 61

1.5.3. From the stability of forms... to a whole new scale: the Grand Erg Occidental 65

1.6. Conclusion: a new paradigm to explain the organization and orientation of active dunes 70

1.7. Martian dunes, still mobile… 72

1.8. References 75

Chapter 2. Humans and Winds in Deserts 79
Yann Callot

2.1. Traditional societies and the wind 80

2.2. The battle against sand encroachment, or the Barrel of the Danaids: the Zouerate railroads (Mauritania) 83

2.3. The Dust Bowl, the first ecological disaster of the 20th century in a developed country 87

2.4. The western Algerian Green Barrier, or an error in management 91

2.4.1. A “barrier” in an unfavorable physical environment 91

2.4.2. Difficult implementation 93

2.4.3. A basic error in understanding aeolian dynamics 98

2.5. References 105

Chapter 3. Living in Deserts 107
Marc Cote

3.1. Humans and the desert 108

3.1.1. A “desert civilization” 108

3.1.2. There are deserts and then there are deserts 108

3.1.3. The desert, Islam and oil 110

3.1.4. Antagonistic and complementary civilizations 110

3.2. Bedouin civilizations 113

3.2.1. Nomads 113

3.2.2. The power of the group 114

3.2.3. Astonishing knowledge 114

3.2.4. The fundamentals of pastoralism 115

3.2.5. Nomad territories 117

3.2.6. Collective lands 118

3.2.7. Dromedaries and Bactrian camels 120

3.2.8. A large-scale ecological transformation: desertification 122

3.2.9. Social transformation: sedentarization 123

3.2.10. New forms of pastoralism 123

3.2.11. The new faces of group structure 125

3.3. Hydraulic civilization 126

3.3.1. Oasis life 126

3.3.2. The fundamentals of hydraulic civilizations 126

3.3.3. Water territories 127

3.3.4. Cradles of hydraulic civilizations 127

3.3.5. Hydraulic techniques 129

3.3.6. Collective and individual hydraulic systems 132

3.3.7. Modes of sharing a rare resource 134

3.3.8. The diffusion of techniques 134

3.3.9. Hot deserts and cold deserts 137

3.3.10. Today: from small wells to deep drilling 138

3.4. A salt civilization? 140

3.4.1. Societies in quest of salt 140

3.4.2. Salt territories 141

3.4.3. The logistics of salt 142

3.4.4. An important period in the history of the Sahara 143

3.4.5. A salt civilization? 144

3.5. Urban civilizations in the desert 144

3.5.1. Cities 144

3.5.2. The fundamentals of urban life 145

3.5.3. The city and the road 147

3.5.4. Networks of urban centers 148

3.5.5. Capitals under the sun 149

3.5.6. The city and water 150

3.5.7. The city and the desert today 153

3.6. Conclusion 153

3.7. References 154

List of Authors 157

Index 159