IB Geography Hot Arid Desert Landforms

Dunes

Dunes

Loose sand transported by saltation, suspension, and surface creep → obstruction → sand accumulates on leeward side

Wadis

Dry gullies/river beds eroded by flash floods

Heavy rainstroms(100-250mm) create torrents on steep slopes

Wadi Rum, Jordan

Deflation

Wind creates blowout

Creates oasis if it erodes below water table

Qattara Depression in Egypt → 122m below sea level

Alluvial Fans

Bottom of desert mountains, streams spread out, deposit transported material

Rock Pedastals

Sedimentary rock → more and less resistant

Wind can only lift sand 1.5m off the ground → mushroom blocks

Mesas and Buttes

Relic hills isolate by water erosion, horizontally bedded sedimentary rock, more resistant cap stone on top

M = wider than tall

B = taller than wide

Desert Erosion

Largely wind, some water

Weathering

Temperature change weathering, chemical weathering (oxidation), mechanical weathering

Deposition

Wind and water