Qin And Han Dynasties Irrational Human Development The Importance Of Factors Leading To The Northwest Of Ecological Environment Changes

When it comes to the ecological environment changes of the Northwest China, someone usually uses the environment decision to be as the main reason. I think that this is incorrect. Because history already proves that pretty mountain and stream has ever being in the Northwest China. There also have a lot of proofs that unreasonable development of human broke the pretty mountain and stream, caused such as the soil erosion, desertification and other changes.The dry weather of the Northwest China is a background factor of ecological environment change, we shouldn't neglect it. What we wants to do is with the research method of the environment history to analyze and prove that the unreasonable development of mankind is a decisive factor to cause ecological environment changes of Northwest China. All these should be under the bad nature environment in northwest at the same time.Take history period of Qin and Han dynasties as an example, we emphasize the research of two ecological problem: desertification and soil erosion.The typical model examples of desertification are Hexi hallway and Loulan. The Hexi hallway is a natural ranch where some minority nation live . The emperor Liuche exploited hallway in large-scale. They chopped down forest, opened river and dug carnal as one's pleases and emigrated many people into oasis in flimsy ecosystem to farm. All these unreasonable developments led to the destroying of forest and plant. The oasis also was abandoned finally, and was annexed by the desert. Loulan is also an oasis with flimsy ecosystem. Although dry, it was a prosperous courier station in the Silk Road for being rich water. With the farmland being built by Han in its surroundings and its upper stream regions, the river in Loulan lost much water. A lot of farms were abandoned and turn into desert . Thischanges the destiny of the Loulan. After Han dynasty, Loulan came down in his way with each passing day until it was forgot by us.The typical model example of the soil erosion are the yellow river, the Jing river and the Wei river .The yellow river deluge frequently in the Western Han dynasty , but in the Eastern Han dynasty Wangjing cures river .Since then there was a long period of peaceful flow .This variety of flooding and peaceful flow agreed with the moment when the boundary between agriculture and pasturage moved .Wangjing did a good job. What was the reason of the yellow river deluge? we discover the serious soil erosion caused by the change form pasturage to agriculture is the chief criminal. It is same to the Jing river and the Wei river. The Wei river area was exploited by mankind, but the river of Jing was not. So the Jing river is pure and the Wei river is muddy in the Spring and Autumn period. There are many people lived in the Jing river area in Qin and Han dynasties,and opposite to the Wei river area ,the ecosystem of the Jing river was much flimsy. So the Jing river is muddy than the Wei riverWe can make a conclusion that the unreasonable development is the deciding factor of the ecological environment changes of Northwest China in Qin and Han dynasties through upper analyses. But when we research the following history period , we find the conclusion also right. This conclusion must be a caution to big exploitation in the west part of our country.