Desertification - 1 Flashcards
Define land cover.
Provide examples of land cover.
The natural state of the biophysical environment developed over time, as a result of the interconnection between climate, soils, landforms, flora and fauna and human activity.
Examples of land cover include biomes such as forest, grassland, tundra and wetlands, as well as land covered by ice and water.
State how land cover can change through climate change.
Through climate change, the Earth changed significantly from the last glacial maximum to present-day. 21,000 to 17,000 years ago, global temperatures were approximately 4C cooler, sea levels were approximately 100m lower, whilst 30% of the Earths land cover was made up from ice. Since then, temperatures have risen, sea levels has risen, ice cover has decreased, whilst forest cover has increased significantly.
State how land cover can change through geophysical changes.
Volcanic activity produces outflows of lava, ash, and rock that can cover surrounding land cover. A combination of hot ash, lava fragments, and gasses can be explosively ejected from a volcano, these are known as pyroclastic flows. Pyroclastic flows can travel long distances, destroying land cover in its path. However, lava and ash can create very fertile soil, as they are rich in minerals. This can aid in the regrowth/growth of forest cover.
Define desertification.
Provide general examples of what may provoke desertification.
The process of land in dryland regions becoming more arid and desert-like.
Human activities, loss of vegetation cover, a variable climate and drought.
Describe natural processes and human activities that contribute to desertification in China.
The long history of unsustainable intensive logging practices has led to increased wind speeds and soil erosion. e.g During the 1980s the government removed a plant called ‘sea buckthron’, this played a vital role in holding the soil together.
Climate change is contributing to declining rainfall and falling watertables.
The expansion of cropland into drylands has decreased the watertable, creating highly erodible soils.
China’s windy climate makes the land’s soils susceptible to wind erosion.
The boom pollution rate in China has rendered much of the soil unusable.
