Section B - Hot Desert Flashcards
What is the Climate of a Hot Desert?
Daytime temperatures exceed 40 degrees in the day and below 0 degrees at night, with less than 250 mm of rainfall a year.
What is the soil like in a Hot Desert?
Soil is thin, sandy, rocky and grey and is dry and infertile due to lack of organic material, Soil surface is crusty due to lack of rain as hot water is evaporated causing salts to be left behind
Name 3 Camel adaptations to survival in a Hot Desert.
Camels store fat in the hump to break down into food and water. Rarely sweat to conserve fluids. Have large tough lips to eat dry thorny vegetation. Broad flat leathery feed to spread weight and protect from the hot sand. Lose little water through urination and respiration. Have slit-like nostrils and two rows of eyelashes to protect from airborne sand.
Name 3 Prickly Pear Cactus adaptations to survival in a Hot Desert.
Small Leaves- Ensure less water is lost through transpiration due to lower surface area
Tap Roots- are long (7-10 metres) that go deep to access groundwater supplies during droughts
Spines- thinner and thicker than leaves so less water is lost and deters animals from eating plants
Waxy Skin- Leaves have thick waxy skin to reduce water loss by transpiration
Water Storage- some plants are known as succulents store water in stems leaves roots and even fruits
Short Life Cycle- Germinate the following rainfall and die within a short space of time to avoid droughts
What are the interrelationships in a Hot Desert?
Interdependence between the different components (climate, water, soils, plants, animals and people) of the hot desert is essential for life to thrive. The living components that inhabit the hot desert are connected to each other and the physical environment. For example, people are dependent on their animals for milk and food as well as their use as pack animals. Humans are also dependent on water for their survival.
Define Desertification
When deserts are expanding due to soil erosion turning productive land into non-productive land thus degrading it
Name and explain the 6 causes of desertification.
Population growth- increase in population puts greater pressure on the environment for resources such as wood and water
Removal of wood- when land is cleared of trees, the roots no longer hold the soil together so it’s more vulnerable to soil erosion
Overgrazing- Vegetation is grazed by cattle leaving the soil more vulnerable to soil erosion as there are no roots to hold it together
Soil Erosion- soil is more exposed to sun, wind and rain so the soil is often washed off with its nutrient or blown away
Climate Change- Due to desert regions getting drier it increases the risk of drought
Over-cultivation- as the population grows so does farming gets more intensive as more food is required thus causing the land to become infertile.
Name 3 Impacts of Desertification.
In 2014 the UN stated that 20 million people in the Sahel region of Africa faced hunger and required £2 billion in food aid due to desertification
Famines do happen and 250,000 people died in the Sahel drought in 1968-73.
How do Zai Pits help reduce desertification?
restores degraded soil by placing the organic matter in holes to provide nutrients and attract termites which creates holes that allow water to soak in preventing soil erosion. It has edges that trap wind-blow nutrients.
How do Stone contour bands help reduce desertification?
to harvest rainwater and reduce soil erosion stones are precisely placed at the same elevation slowing down the flow of water and preventing minerals from being washed away
How does Tree grafting help reduce desertification?
unwanted stems in the trees are removed as they uptake scarce minerals and water thus wasting them but instead the main stems can increase the fruit production
What are the Benefits of Solution to Desertification?
These solutions have reduced desertification and shown a 40% increase in crop productivity after the first year. This in return causes farmers to share their more effective and efficient methods with other farmers thus further reducing desertification.
Wester Desert Case Study - Location?
The Western Desert extends over 200,000 square kilometres and is located in the southwest of the USA. The Western Desert comprises three deserts, the Sonoran Desert, the Mojave Desert and the Chihuahuan Desert. It extends across several states including California, New Mexico and Arizona.
Wester Desert Case Study - Water Supply?
Precipitation levels in the Western Desert are very low at around 55mm per year, and evaporation rates are high. Stable water supplies are essential for economic development. To meet demand the Hoover Dam was constructed on the Colorado River to provide water for drinking and irrigation.
Wester Desert Case Study - Accessibility?
Access to the Western Desert is limited to major cities such as Chicago and Las Vegas. Major routes such as Route 66 provide links to major urban areas.
