Deserts and Desert Environments

1. Introduction: Defining the Desert System.

1.1. Defining the Desert System.

1.2. Evolution of Deserts.

1.3. Indices of Aridity.

1.4. Desert Surfaces.

1.5. Tectonically Stable and Unstable Deserts.

1.6. Deserts of the Past.

1.7. Changing Human Perspectives on Deserts.

2. Deserts of the World.

2.1. Introduction: the Extent of Global Aridity.

2.2. Global Deserts.

3. The Climatic Framework.

3.1. Introduction: Classification of Deserts by Temperature.

3.2. Weather Data.

3.3. Atmospheric Controls: Surface Boundary Layer.

3.4. Temporal and Spatial Variability of Climatic Influences.

4. The Hydrologic Framework.

4.1. Introduction.

4.2. The Water Balance in Deserts.

4.3. Water Budgets.

4.4. Surface Runoff and Floods.

4.5. The Chemical Quality of Surface and Soil Water.

4.6. Water Resources.

4.7. Case Study: the Waters of the Tigris-Euphrates Basin and the Impact of Modern Water Management.

5. Lake Systems: Past and Present.

5.1. Introduction to Desert Lakes.

5.2. Types of Lake.

5.3. Lakes of the Global Arid Environment.

6. Weathering Processes and Hillslope Systems.

6.1. Introduction.

6.2. Weathering.

6.3. Weathering Forms.

6.4. Duricrusts.

6.5. Desert Varnish.

6.6. Hillslope Processes.

6.7. Composite Surfaces (Pediments).

7. Desert Soils and Geomorphic Surfaces.

7.1. Introduction.

7.2. The Nature of Soils in Arid and Semiarid Regions.

7.3. Soil Description and Classification.

7.4. Soil Characteristics of Arid Regions.

7.5. Inorganic and Biological Soil Crusts.

7.6. Spatial Heterogeneity in Soil Properties and the Ecohydrology of Patterned Vegetation Zones.

7.7. Surface Volume Changes.

7.8. Surface Types: Hamada and Stone Pavements.

8. Water as a Geomorphic Agent.

8.1. Introduction.

8.2. Groundwater Sapping in Slope and Valley Development.

8.3. Piping Processes in Channel and Slope Evolution.

8.4. Fluvial Processes.

8.5. Fluvial Landforms.

9. Aeolian Processes.

9.1. Introduction.

9.2. Near-surface Flow.

9.3. Wind Processes.

9.4. Landforms of Accumulation: Sand Sheets, Zibar, and Sand Stringers.

9.5. Landforms of Accumulation: Dunes.

9.6. Ripples.

10. Landforms of Aeolian Erosion and Desert Dust.

10.1. Introduction.

10.2. Deflation Features: Desert Depressions and Pans.

10.3. Ventifacts.

10.4. Yardangs and Ridge and Swale Systems.

10.5. Desert Dust.

11. Plant communities and their Geomorphic Impacts.

11.1. Introduction: Characteristics of Desert Ecosystems.

11.2. Adaptations to Desert Conditions.

11.3. Plant Communities and Ecotones.

11.4. Succession in Desert Plant Communities.

11.5. Dune Communities.

11.6. Vegetation Type and Density and Relationship to Geomorphic Processes.

12. Animal Communities.

12.1. Introduction: Environmental Requirements.

12.2. Effects on Geomorphic Processes.

12.3. Hydrologic Impacts.

12.4. Effects of the Geomorphic Activity of Animals on Plant Communities.

13. Desertification and the Human Dimension.

13.1. Desertification: Introduction and Terminology.

13.2. Climate Change and Desertification.

13.3. Anthropogenic Causes of Desertification.

13.4. Water Resources: a Rural and Urban Problem.

13.5. Case Study: the Aral Sea.

13.6. Discussion.

Index