Arid climates Flashcards
What constitutes an arid climate?
Generally an area that gets less than 250mm of rainfall per year, anywhere in this zone can be classed as a desert, which can be hot or temperate.
Where are hot deserts?
They occur around 30 degrees North and South of the Equator, max air temps are above 40 degrees
Where are temperate deserts?
Occur at higher latitudes e.g. central asia. Cooler than deserts but still arid and dry.
Why is agriculture so difficult in these climates?
Rain is rare and inconsistent, so hard to capture, especially as it mostly falls during flash flooding which causes soil erosion
Temperature shifts from extreme heat in the day to very cold at night, so hard for plants to have the right growing conditions.
What is the population structure in these areas?
Population is low (2.5 million Sahara) and distribution is clusters of small settlements near water sources.
Where has agriculture ocurred?
Near oases where water can be drawn from to irrigate nearby crops.
- Crops such as cereals can be grown in the shade of taller food plants such as date palms. Which have allowed some people to settle near oases.
- Some nomadic people exist here, due to oases they can migrate with animals who can graze at oases with vegetation - animals eat plants at one place and move.
What are the modern solutions to the challenges of living in arid areas?
Motorised pumps can be used to more easily access groundwater for irrigation. Such as drip irrigation, where water slowly drips onto plants to avoid evaporation loss.
- Economic development is often hindered by the climate, but major cities can develop with enough investment into obtaining water. Such as Las Vegas in the Mojave Desert, using water from Lake Mead; a reservoir created by a huge dam on the Colorado river.
