Dunes - Dynamics, Morphology, History

Informationen zum Autor Andrew Warren is Emeritus Professor of Geography, University College London where he has taught since 1964. He previously worked as soil surveyor in Pakistan with Hunting Technical Services limited, and in 2000, he was awarded the King Carl XVI Gustaf's Professorship in Environmental Science at the Royal Swedish Academy of Sciences, University of Lund. Klappentext Dunes is the first book in over a decade to incorporate the latest research in this active and fast-developing field. It discusses the shapes, sizes, patterns, distribution, history and care of wind-blown dunes, and covers all aspects of dunes, terrestrial and in the Solar System.* The only book to cover all dunes, terrestrial and in the Solar System, in deserts, on coasts, and in the past* Represents the most current update on the research of dunes for over a decade* Incorporates the latest research to come out of China where the field is most rapidly expanding* Discusses the most recent range of skills and technology now focused on the study of dunes* Brings up-to-date a rapidly expanding field Zusammenfassung Dunes is the first book in over a decade to incorporate the latest research in this active and fast-developing field. It discusses the shapes, sizes, patterns, distribution, history and care of wind-blown dunes, and covers all aspects of dunes, terrestrial and in the Solar System. Inhaltsverzeichnis List of Figures xi Acknowledgements xv Introduction 1 Part One 0.3 mm; 100,000 m2; >10 years) 208 Constraints 208 Complexity 208 Uncertainty 210 Environmental change 210 Sustainability 211 Coastal dunes 211 Stabilised inland dunes 212 References 213 Index 214

Sommario

List of Figures xi
 
Acknowledgements xv
 
Introduction 1
 
Part One
 
1 Wind and Sand 7
 
Wind versus Bed 7
 
The Law of the Wall 8
 
Improving the wind/bed model 9
 
Lift-Off 12
 
Holding down by gravity 12
 
Holding down by cohesion 12
 
Raising by lift 13
 
Raising by drag 13
 
Raising by bombardment 14
 
Thresholds 14
 
Grain size 16
 
The slope of the bed 17
 
The dynamics of water content 17
 
Crusts 19
 
Pellets 20
 
Sand in Motion 20
 
Saltation 20
 
Streamers and other medium-scale patterns of saltating sand 22
 
Reptation 22
 
Creep 23
 
Other near-surface activity 23
 
Suspension 24
 
The vertical distribution of load and grain size 24
 
The saturation length 24
 
The fetch effect 26
 
The response of a loose bed to erosion by the wind 27
 
The Transport Rate 27
 
Shapes, densities and mixtures of size 29
 
Hard surfaces 30
 
Rough surfaces 30
 
Moisture, temperature and humidity 31
 
Rain 31
 
References 31
 
2 Ripples 32
 
Subtypes 35
 
Models 36
 
Flow response 36
 
Gravity wave 36
 
Saltation length 37
 
Shadow zone 37
 
Mathematical 37
 
Pattern 38
 
3 The Form and Behaviour of Free Dunes 39
 
Definitions 39
 
Early Stages 39
 
Start 39
 
Minimum size 40
 
The Profile of a Fully Grown Dune 41
 
Toe 41
 
Windward slope (or 'stoss slope') 43
 
Crest 45
 
Lee slope 46
 
Movement 53
 
Turnover time, bulk transport 56
 
Size 56
 
Flow-hierarchy models 57
 
Grain-size models 57
 
The time/supply model 58
 
References 58
 
Part Two 1000 to 10,000 m2; 100 to 1000 years 59
 
4 Pattern in Free Dunes 61
 
Definitions 61
 
Wind-Directional Regimes 62
 
Global winds 62
 
Local wind systems 62
 
The Classification of Wind-Directional Regimes 65
 
Wind-Directional Regimes and Dune Pattern 66
 
Transverse Dunes 66
 
Two-dimensional pattern: vertical and downwind 67
 
Two-dimensional pattern: horizontal and transverse to the wind 68
 
Self-organisation 69
 
Barchans 71
 
Quasi-transverse patterns 75
 
Linear Dunes 80
 
Introduction 80
 
Models of formation 82
 
Sand Sheets 88
 
Dunes with Distinctive Sand 90
 
Gravel dunes 90
 
Zibars 91
 
Clay dunes 92
 
Lunettes 92
 
Gypsum dunes 93
 
Diatomite sands 93
 
Volcanic sands 93
 
Snow and ice dunes 94
 
Niveo-aeolian deposits 94
 
References 94
 
5 Forced Dunes 96
 
Dunes Built around Bluff Obstacles 96
 
Climbing and echo dunes 96
 
Flanking and lee dunes 97
 
Cliff-top and falling dunes 99
 
Dunes on Gently Sloping Terrain 99
 
Reference 99
 
6 Dunes and Plants 100
 
Wind, Sand and Plants 100
 
Rigid objects 100
 
Spatial pattern 101
 
Porosity 102
 
Flexibility 102
 
Plants as living things 103
 
The broader time/space framework 104
 
Dunes among Plants 104
 
Nebkhas 104
 
Blowouts 107
 
Parabolic dunes 109
 
References 111
 
7 Coastal Dunes 112
 

Relazione

"This is a terrific read for both specialists and nonspecialists. Summing Up: Highly recommended. Upper-division undergraduates through professionals/practitioners." ( Choice , 1 February 2014)

Dettagli sul prodotto

• Autori: Andrew Warren, Andrew (University College London Warren
• Editore: Wiley, John and Sons Ltd
• Lingue: Inglese
• Formato: Copertina rigida
• Pubblicazione: 10.05.2013
• EAN: 9781444339697
• ISBN: 978-1-4443-3969-7
• Pagine: 236
• Serie: RGS-IBG Book Series
• Categorie: Scienze naturali, medicina, informatica, tecnica > Geoscienze > Geografia; Geomorphologie, Geowissenschaften, Geographie, Geography, Düne, Earth Sciences, Physical geography, Geomorphology, Physiogeographie