The Earth’s surface is covered by 71% water and 29% land. Also, there is one-third of the desert area that’s included in the 29% of the land. The definition of desert refers to sandy decertified land, which is the terrain covered by quicksand and dunes. Therefore, rain is scarce, plants are scarce, and the air is dry in the desert which is not a suitable environment for human survival. Generally, people think that the desert is uninhabited, but there are many animals hidden in the desert, such as ostriches, rattlesnakes, cobras, lizards, scorpions, and jerking mice. They all have the physiological characteristics of drought tolerance and do not need to drink water. They can obtain water directly from the plant and rely on special metabolic methods to obtain the required water. Due to the large temperature difference between day and night in the desert, many animals are nocturnal. There are many famous deserts in the world, such as the Sahara Desert, Arabian Desert, Libyan Desert, and Australian Desert. Among them, the Sahara Desert is the largest in the world which formed about 2.5 million years ago. It is located in northern Africa, south of the Atlas Mountains and the Mediterranean Sea. Although the climatic conditions are harsh and unsuitable for human survival in the Sahara Desert, there are abundant mine resources in the desert, such as oil, natural gas, uranium, and iron. However, since 1920, the area of the Sahara Desert has increased by 10%.
With the continuous abuse of the earth’s resources by humans, and the occupation of land by the rapid increase in population, land resources are depleted, and desertification has appeared in arid and semi-arid areas. The definition of desertification is that the combined effects of human factors and natural factors (such as overgrazing, destruction of vegetation, drought, and lack of rainfall, etc.), have resulted in the destruction of the surface environment and land degradation in arid and semi-arid sandy regions. Fertile land affected by desertification will lose nutrients. After the land is barren, the soil layer is thin and the vegetation and crops cannot survive, which affects people’s lives.
Due to the influence of climate change and desertification, in the 1970s, the farmland and pastures on the southern edge of the Sahara Desert gradually became desertified, which caused famine and displaced people. According to UNEP (United Nations Environment Programme), land desertification has affected 36 million square kilometers of land. It is estimated that the lives of 250 million people were affected by desertification; until 2045, desertification will cause 135 million people to be displaced.
“Desertification.” Desertification: 1. What Is Desertification?, www.greenfacts.org/en/desertification/l-2/1-define-desertification.htm.
Rain-Fed Croplands. www.britannica.com/science/desertification/Rain-fed-croplands.
“荒漠化.” 到百科首页, baike.baidu.com/item/%E8%8D%92%E6%BC%A0%E5%8C%96/313632?fr=aladdin.