Hot Deserts Summary Sheet

1. location hot deserts are found on the west coasts of continents north and south of the Equator i.e.:-
(i) Atacama ............................South America
(ii) Namib - Kalahari .............Southern Africa
(iii) Great Australian ..............Australia
(iv) Nevada - Arizona ............North America
(v) Sahara ..............................Northern Africa
(vi) Arabian ...........................Middle East
(vii) Thar ...............................Indian Sub - Continent

2. climate hot and dry all year round (less than 250 mm of precipitation). Some hot desert areas have a 'wet' season e.g. South West U.S.A. (see graph below).

 

3. vegetation

Plants have adapted to this very hot + dry environment in a number of ways:-
A thick waxy skin can reflect some of the heat and reduce loss of moisture. Other plants have thorns instead of leaves for the same reason.
Some plants can store water in bulbs in their roots.
Cactus plants can store water in their tissues and protect itself from animals or birds wishing to use this water by spikes, needles or poisons.
Some plants (e.g. date palms) have roots which go down deep into the soil to reach groundwater whilst others (e.g. cactus) have very long shallow root systems to collect whatever rain ralls over a fairly large area. Such plants often 'fire' their seed pods several metres from the parent plant so that their root systems will not compete for rainfall.
Desert flowers or shrubs (e.g. rose of Jericho) can lie dormant in the drought conditions for many years and bloom in short periods when there is rainfall in order to release their seeds.
Tumbleweed pulls up its roots and allows itself to be blown into 'wetter' desert areas.

4. peoples' use of the environment

traditional farming oasis agriculture with irrigation (e.g. dates)
nomadic herdsmen (cattle + goats)
modern farming irrigation is used to produce cotton and
mineral exploitation (particularly oil)
tourism e.g Eliat in Israel, Las Vegas in Nevada
retirement settlements the hot dry climate is seen as desirable by many retirees
military activity weapons testing + military training

5. peoples' abuse of the environment

overgrazing as nomadic herdsmen become more settled or their population increases. Overgrazing on the Desert fringes is leading to an expansion of desert areas.
overuse of irrigation can lead to salinisation of the soil, where natural salts from below the ground are brought to the surface in solution and deposited there as the water evaporates. This happens where an excess of water is used and this layer of salt ruins the soil for future use e.g. Arizona + California.
danger of pollution from oil leaks from pipelines + wells. There is also a danger to these installations from terrorism as these are Prime economic targets. This can lead to wars.
tourism uses valuable scarse water resources e.g. Las Vegas takes vast amounts of water from the Colorado River and pumps an enormous volume of underground water to supply swimming pools, fountains and golf courses.
tourism can also damage local customs and traditions in developing countries i.e. local people see and desire the Western Lifestyles they see e.g. televisions, expensive trainers + designer clothes.
retirement settlements also consume vast amounts of water for domestic + leisure use. Industrial towns are also rapidly developing in deserts and these pollute the air with their vehicular + industrial; fumes e.g. Phoenix.

 

 

 

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