土地沙漠化英文介绍 desertification.doc

Desertification is a type of land degradation in which a relatively dry land region es increasingly arid, typically losing its bodies of water as well as vegetation and wildlife. It is caused by a variety of factors, such as climate change and human activities. Desertification is a significant global ecological and environmental problem.
Let’s begin with the areas affected by the desertification
Drylands occupy approximately 40–41% of Earth’s land area and are home to more than 2 billion has been estimated that some 10–20% of drylands are already degraded, the total area affected by desertification being between 6 and 12 million square kilometres, and that a billion people are under threat from further desertification. The Sahara is currently expanding south at a rate of up to 48 kilometers per year.
But how is the ing into being? Here are some Causes.
Desertification is caused by two main categories of factors: natural factors and, more importantly, human natural factors causing desertification include the following:
1. The climate has a major influence through rainfall, solar radiation and wind, which affect the rates of physical and mechanical erosion as well as chemical and biological degradation of soil.
relief of a land affects the rate of soil erosion by water.
textile, structure, and chemical and biological status of soil are