hot deserts keywords

abrasion

where material carried by moving wind or water hits exposed rock surfaces, thus wearing them away. Often referred to as a sandblasting or sandpapering effect.

aeolian

relating to the action of the wind

arid

the climate of an area that receives less than 250mm of rain per year

aridity index

the ration between potential evapotranspiration and precipitation

chemical weathering

the processes leading to the decomposition or breaking down of rocks due to chemical reactions. This most often requires the presence of water and/or exposure to the air.

continentality

the impact of increasing distance from the coast on the climate of an area

deflation

where wind removes dry, unconsolidated sand, silt and clay particles from the surface and transports them away

deposition

occurs when the velocity of the wind decreases until it can no longer transport the grains it is carrying

desert

an arid environment recieving very low levels of rainfall

desertification

the persistent degradation of dryland ecosystems by human activities and climate change

endoreic streams

where rivers occupy drainage basins that are closed and do not flow

ephemeral streams

streams that flow intermittently in hot desert areas following thunderstorms

erosion

the wearing away of Earth’s surface by the mechanical action of processes of glaciers, wind, rivers, marine waves and wind

exfoliation

a process of mechanical weathering that results in the breaking, splitting or peeling-off of the outer rock layers. Also commonly known as 'onion skin weathering.

exogenous streams

Rivers that originate external to the desert in adjacent highlands and more humid environments, flow from outside of the desert and pass through it.

insolation

the incoming solar radiation that reaches the Earths surface

mass movement

the movement of material downhill under the influence of gravity, but may also be assisted by rainfall

saltation

a process where sand-sized particles are transported by bouncing and hopping along the surface

sediment

any naturally occurring material that has been broken down by the processes of weathering and erosion and then has been transported and subsequently deposited by the action of ice, wind or water

sediment budget

the balance between the input and output of sediment in hot deserts

semi-arid

the climate of an area that receives between 250 and 500mm of rain per year

surface creep

where saltating particles return to the surface and hit larger particles that are too heavy to hop: they slowly creep, slide or roll along the surface from a combination of the push of the saltating grain and the movement of the wind

suspension

transportation by the wind where the smallest particles are held in the air

thermal fracture

the weathering of rock resulting from its rapid and repeated heating and cooling

transpotation

the processes that move material from the site where erosion took place to the site of depositionw

water balance

the relationship between the annual precipitation received and the amount of water lost to PET

weathering

the breakdown and/or decay of rock at or near the Earth's surface creating regolith that remains in situ until it is moved by later erosional processes. Weathering can be mechanical, biological/organic or chemical.