Examples are given to illustrate the unreasonable behavior of human beings in transforming landforms.

Unreasonable use of land, predatory development and construction, indiscriminate cutting, indiscriminate stacking and indiscriminate excavation; Others indirectly destroy topsoil and vegetation, such as deliberately or conniving at livestock and poultry. In recent years, raising birds (mainly chickens and ducks) in mountainous areas is in the ascendant, which has seriously damaged water and soil resources./kloc-soil resources all over the world have been seriously damaged since the 9th century. Soil erosion, soil salinization, desertification, impoverishment, flood and drought disasters caused by natural ecological imbalance. , make the cultivated land degradation, loss of production capacity. At present, there are about 654.38+0.5 billion hectares of cultivated land in the world. Due to soil erosion and soil degradation, 5 million to 7 million hectares are lost every year.

One of the important reasons for the decline of the ancient Roman Empire and the Babylonian Kingdom of Cuba is that soil erosion leads to the deterioration of the ecological environment and the poverty of the people; The Greeks and Asians Minor destroyed forests for land reclamation, causing serious soil erosion and turning dense forests into uninhabited wasteland.

In addition to soil erosion, there is also land desertification. Human factors include excessive reclamation, grazing and logging, and unreasonable use of water resources. For example, before the Tang Dynasty, the Mu Us sandy land in Yulin and Jingbian areas in northern Shaanxi was a place with abundant aquatic plants. Later, the climate became drier, and there were more and more records of quicksand since the Song Dynasty. During Chenghua period in the early Ming Dynasty (1970s), in order to prevent nomads from plundering south, the Central Plains Dynasty built the Great Wall in this area, immigrated to the garrison, and reclaimed land on a large scale, which aggravated desertification. /kloc-Since the 8th century, under the name of "immigrant frontier", the Qing government has cultivated seeds by immigrants, which eventually destroyed the grasslands in areas dozens of kilometers wide outside the Great Wall, forming a scene of quicksand everywhere.

That's all.