The causes of desertification in northwest China: why desertification in northwest China?

1. natural factors: the formation of land desertification is actually a complex process, which is the result of the interaction between unreasonable human economic activities and fragile ecological environment. Natural geographical conditions and climate variation create conditions for the formation and development of desertification, but its process is slow, and human activities stimulate and accelerate the process of desertification, which has become the main cause of desertification. Abnormal climatic conditions, especially severe drought conditions, easily lead to vegetation degradation and accelerate wind erosion and desertification. Drought climate conditions largely determine the fragility of the local ecological environment, so drought itself contains the potential threat of desertification; Abnormal climate will unbalance the fragile ecological environment, which is the main natural factor leading to desertification. When the climate is dry, desertification will develop; When the climate becomes humid, desertification will be reversed. Global warming, the increasingly serious drought and semi-arid trend in the northern hemisphere have all led to the intensification of desertification.

2. Climatic factors: The updraft in the equatorial region flows to the poles at high altitude. Due to the influence of the earth's rotation bias, most of the air does not move forward near 30 north and south latitudes, but accumulates in the high altitude and cools down through radiation. The near-surface gas layer keeps high pressure all the year round, which is called "subtropical high pressure area" in meteorology. In addition to the monsoon climate zone on the east coast of Eurasia, this area has a dry climate and few clouds and rains, making it the main desert distribution area.

3. Unreasonable human production activities: population growth and economic development have brought too much pressure on the land. Over-reclamation, overgrazing, deforestation and unreasonable use of water resources have seriously degraded the land, destroyed the forest, and gradually dried up the climate, eventually forming a desert.