Desert Landscapes

Deserts

Dry regions cover 30 percent of Earth’s land surface

Distribution and causes of dry landsTwo climatic types are commonly recognized

Desert or arid

Steppe or semiarid

Arid and Semiarid Regions

Figure 12.15

Rainshadow Desert

Figure 4.21

Wind Processes and Desert Landscapes

The Work of Wind  Overview of Desert Landscapes  

The Work of Wind Eolian Erosion  Eolian Transportation  Eolian Depositional Landforms  Loess Deposits  

The Work of Wind

Figure 12.1

Desert Pavement

Figure 12.2

Yardang

Figure 12.3

Dust Over the Red Sea

Figure 12.4

Sand Transport

Figure 12.5

Sand Transport

Figure 12.5

Sand Ripples

Figure 12.7

Dune Cross Section

Figure 12.9

Major Dune Forms

Figure 12.10

Sand Dunes in the Western United States

Sandy Regions of the World

Figure 12.12

Loess Regions of the World

Figure 12.14

Loess Deposits

Figure 12.13

Overview of Desert Landscapes  Desert Climates  Desert Fluvial Processes  Desert Landscapes  Desertification

Death Valley

Alluvial Fan

Figure 12.17

DifferentialWeathering

Figure 12.18

Cross Bedding

Figure 12.20

Deserts

Role of water in arid climatesMost streambeds are dry most of the timeDesert streams are said to be ephemeral

Carry water only during periods of rainfallDifferent names are used for desert streams

in various region Wash and arroyo (western United States) Wadi (Arabia and North Africa)

DesertsRole of water in arid climates

Ephemeral streamsDifferent names are used for desert streams

in various regions Donga (South America) Nullah (India)

Desert rainfallRain often occurs as heavy showers

DesertsRole of water in arid climates

Desert rainfallBecause desert vegetative cover is sparse,

runoff is largely unhindered and flash floods are common

Poorly integrated drainage systems and streams lack an extensive system of tributaries

Most of the erosion work in a desert is done by running water

A Dry Channel Contains Water Only Following Heavy Rain

Figure 4.22

Basin and Range

Figure 12.21

Colorado River Basin

Figure 1

Inselbergs in So California