Hot Deserts Flashcards
Physical characteristics of Hot desert (Lack of water makes them low nutrient ecosystems)
- High average temperatures
- Very low precipitation
- Located at Subtropics
- 30 degrees north and south of the Equator
Interdependence of climate
- Low level of precipitation
- Heat is challenging for plants so only few species survive
Interdependence of water
- Low rainfall means decomposition only works very slowly
- Desert biomass store is small because of lack of water and low supply of nutrients
Interdependence of soil
-Soil store is largest store- there are so few plants taking up nutrients
Adaptations of plants
- Can store water (like agave) - often protected by spines
- Large root networks- either deep to get to groundwater or wide and shallow = absorb as much water as possible when it does rain
- Have seeds that only germinate when it rains - they can live dormant for many years
Adaptations of animals
- Nocturnal = by being active at night animals can avoid high day time temperatures- go underground
- Getting water from food rather than needing to drink
- Big ears radiate heat efficiently
Development opportunities
MINING - the desert has valuable reserves of minerals such as feldspar, phospherite, gypsum and kaolin. These minerals are used to produce a range of things from cement to fertilisers and are therefore valuable. Limestone and marble are also quarried in the area. Limestone is used for building and producing cement, and marble is used in construction.
ENERGY GENERATION - energy is produced in the Thar Desert using solar panels. This energy is used to clean water supplies contaminated with salt (desalination). Wind energy is also used to generate electricity. A wind farm consisting of 75 wind turbines has the capacity to produce 60 megawatts (MW) of electricity.
FARMING - irrigation in the Thar Desert has made commercial arable farming viable. Producing crops such as wheat and cotton has created many jobs and generated income for the local economy.
TOURISM - the Thar Desert National Park attracts many visitors who want to see some of the 120 species found there. Tourists explore the desert with local guides on camels. Tourism is an important source of income and creates many jobs for local people. The multiplier effect of tourism creates many development opportunities.
Development challenges
EXTREME TEMPERATURES - temperatures in the Thar Desert can exceed 50°C in the summer months. It is hard for people to farm, work in mines or as tourist guides during these months as it is simply too hot. This makes development difficult.
WATER SUPPLY - the supply of water to the Thar Desert is precious and limited. With only 120-240 mm of rain falling per year in the desert, water must be used sensibly and sustainably. Without water the development of mining, farming and tourism and therefore the economy would not be possible. Some parts of the desert have experienced over-irrigation, which has caused waterlogging of the ground. Here the excess water has evaporated, leaving a layer of salt on the surface making it difficult to grow crops.
INACCESSIBILITY - the desert covers a huge area of 200,000 sq km. Most of the desert is inaccessible due to the extreme environmental conditions and poor infrastructure. Beyond the city of Jaisalmer, development is limited. This has created a honeypot site for tourists in Jaisalmer but not beyond. Inaccessibility to many parts of the desert has led to greater differences between rich and poor.
Desertification definition
The process by which land is gradually turned into desert.
Desertification causes
- climate change
- population growth
- removal of fuel wood
- overgrazing
- over cultivation
- soil erosion
Soil erosion
- Vegetation is very important in dry lands for binding soil and returning nutrients to soil
- when vegetation cover is reduced topsoil loosens and dries and then vulnerable to erosion by wing and water
- without topsoil the soil is left a mixture of dust sand and stones- no good for plants
Over cultivation
- Can use up all the nutrients in the soil
- without soil nutrients plants can’t grow
- without vegetation soil dries out and is eroded
Removal of fuel wood
- demand for fuelwood from increasing population means that trees and bushes are cut down
- without vegetation to protect it topsoil is eroded by wind and water
Overgrazing
- increasing number of grazing livestock = overgrazing
- vegetation binding soil is eaten and soil is eroded
Increasing population
- more pressure on soil and water resources
