: Deserts are open systems- generally in dynamic equilibrium Inputs: Water enters the system through infrequent rainstorms. Sediment can be carried into a desert system by wind or water. Energy: Insolation = the solar radiation that reaches the Earth Insolation is...
A Level>Notes>Physical geography>Hot desert systems and landscapes
Deserts- Distribution and Characteristics
Aridity Index: Water balance = relationship between mean annual precipitaion (P) and potential evapotranspiration (PET). If P>PET = water surplus, vice versa = water deficit. In deserts, P<PET (water deficit). The size of the deficit (difference between P and...
Processes in Hot Deserts
Mechanical weathering: Rock is physically broken into smaller pieces in situ. Thermal fracture: Extreme temperatures in deserts (0-50OC desert air can't block sunlight or trap heat) During the day (when it's hot) rock expand and at night (when it's cold) they...
Landforms in Hot Deserts
FLUVIAL EROSION NAME DESCRIPTION DIAGRAM EXAMPLE Pediments Pediments are desert plains - gently sloping areas of rock (usually covered in a thin layer of debris). They're formed by the erosion of rock by sediment carried in sheet floods or small streams. ...
Hot Desert Environment- Case Study
Introduction: Northern Africa across tropic of Cancer 6km2 across 10 countries Characteristics: Climate: Air circulation causing little moisture over tropics & high pressure of descending air Rainfall: Less than 100mm annual rainfall - mainly via...
Desertification
The degradation of land in arid areas by which fertile land becomes desert like 75 billion tonnes of soil eroded annually Human Causes: Overgrazing Reduces vegetation > soil erosion (due to lack of plant roots) Trampling by animals > compressed &...
Desertification in Yatenga, Burkino Faso, Sahel Region of Sub Saharan Africa- Case Study
Introduction: Desert margins are most vulnerable to desertification E.g Sahel Region of Sub Saharan Africa Causes: 80% of Burkino Faso live on water fed agriculture leading to over cultivation Irregular rainfall: 200-600mmpa with several droughts Fragile aridsols-...