发布时间：2013-04-11 13:45:16 来源：杭州朗阁培训中心 编辑：杭州朗阁小编
Desert, about already accounts for 1/4 of the Earth's surface in recent decades in order to increase faster. The expansion of desert conditions in the area not previously desert-like changes called desertification. Presumably, the earth's surface 1/4 is also being used by this trend threat.
The formation of desertification is mainly due to the reduction of the natural vegetation and thus caused due to wind and water due to soil erosion. In some cases, loosening the soil is scraped away, leaving the surface of the stone. In some other cases, good particle is removed, the sandy particles aggregate to form a movable hills or sand.
Even in areas retain the soil surface, vegetation reduction lead to a reduced ability of the soil to absorb water. Raindrops on the loose soil allows the The good texture particles transfer to the tiny soil voids, making the soil almost can not be water infiltration, absorb the sharp decline in the amount of water, the results of water and soil water increased soil erosion rate increased. Makes the vegetation gradually drying caused the soil absorb moisture decreased ability to further reduce soil progressive deterioration circulation.
In some areas, the increase in the desert area trend caused by the dry weather conditions. Continued global warming in the past thousands of years to make the drought worse. If atmospheric pollution caused by global warming continued to increase, this process can also exacerbate.