Mankind and Deserts 1: Deserts, Aridity, Exploration and Conquests

The wild beauty of deserts has always been a source of fascination the world over. Mankind and Deserts 1 – the first of three volumes – describes their location and geographic variety. There are both hot and cold deserts, those at high altitude or those at sea level, differing in climate but sharing the scarcity of water, extreme temperatures and often violent winds. According to paleoclimate evidence, however, deserts have not always been as arid as they are today. Deserts were a source of inspiration for many spiritual leaders, among them, Moses, Jesus and Muhammad; as well as conquerors, from Alexander the Great to Genghis Khan. Some avoided these deserts, or crossed them as fast as they could. Others adapted to them and developed vibrant civilizations and cities. From ancient, almost mythical, exploration to modern scientific studies, deserts have come to be better known yet still hold great appeal. This book traces the history of their knowledge while providing a basis for understanding their features and the tools needed for their protection, in an ever-changing world.

Table of Contents:
Foreword ix Yvette Dewolf Chapter 1. Introduction: The Concept of a Desert 1 Fernand Joly 1.1. All about a word 1 1.2. Arriving at a definition 2 1.2.1. What is a desert? 2 1.2.2. Conceptual deserts: deserts that have been experienced 4 1.3. The world of deserts 5 1.4. Deserts of the world 7 1.5. To know more 9 Chapter 2. Conquering Deserts 11 Fernand Joly 2.1. Prehistoric times 11 2.2. The dawn of history 13 2.2.1. The Near and Middle East – Sahara 14 2.2.2. Central and East Asia 17 2.2.3. America 19 2.2.4. Southern Africa – Australia 21 2.3. Knowledge of deserts in prehistory 22 2.4. Antiquity 23 2.4.1. The Near East – Sahara 23 2.4.2. The Middle East 24 2.5. Deserts known to Antiquity 26 2.6. Deserts as corridors of migration 28 2.7. Deserts: the birthplace of religions 29 2.7.1. Polytheistic religions 30 2.7.2. Buddhism 31 2.7.3. Judaism 32 2.7.4. Christianity 33 2.7.5. Islam 36 2.8. Deserts and empires in the Middle Ages 38 2.8.1. The Arabs 38 2.8.2. The Turks 41 2.8.3. The Mongols 44 2.9. Deserts known at the end of the Middle Ages 46 2.9.1. Travelers and merchants 48 2.9.2. Medieval geography of deserts 52 2.10. To be continued … 60 2.11. References 62 Chapter 3. Aridity 65 Fernand Joly 3.1. Where we examine semantics 65 3.2. Causes of aridity 67 3.2.1. Meteorological causes 67 3.2.2. Geographic causes 75 3.2.3. Human causes 84 3.3. Climatic factors and the numerical expression of aridity 86 3.3.1. Precipitation 87 3.3.2. Temperatures 95 3.3.3. Evaporation 99 3.3.4. Aridity indices 103 3.4. Nuances in aridity 109 3.4.1. Phytogeographic criteria 110 3.4.2. Hydrological criteria 110 3.4.3. Geomorphological criteria 111 3.4.4. Soil use criteria 111 3.4.5. Sub-desert aridity 111 3.4.6. Desert aridity 112 3.4.7. Hyper-aridity 114 3.4.8. Conclusion 115 3.5. Variations in climatic aridity over time 116 3.5.1. Variations on a geological scale 116 3.5.2. Climatic changes in the Quaternary period 123 3.5.3. Variations on a historic scale – droughts 133 3.6. Unusual phenomena caused by or promoted by aridity 140 3.7. Aridity and drought 144 3.8. References 145 List of Authors 151 Index 153

About the Author :
Fernand Joly (1917–2010) studied the Sahara at the Institut Scientifique Chérifien (Institut Scientifique de Rabat) in Morocco. He then entered the CNRS and Paris VII University, where he developed geomorphology and guidelines for cartography, pioneering digital data treatment. He is the author of Glossaire de géomorphologie. Guilhem Bourrié, a member of the Académie d�Agriculture de France, is a pedologist and geochemist. He has worked on water quality in soils in Brittany, Provence, Algeria, Brazil, Chile and Mexico.