The Jinghe The Historical Changes And Present

The Jing river is the largest tributary of the Wei river and one of the secondary tributaries of the Yellow River, originating from the Ning Xia Hui Autonomous Region and flowing through Ning Xia, Gansu Province, Shaanxi Province. Its vicissitude and development greatly affect the people in the region it runs through; the same, human activities affect the vicissitude of the Jing river.The vicissitude of the Jing river is mainly reflected in channel, water and water quality, and the changes of other elements such as shipping and lakes are also contained. The channel changes of the Jing river are mainly reflected in the changes of its trail and its rush and erosion to the bank. The water amount of the Jing river shows a decreasing tendency. And the water quality of the Jing river differs in each dynasty because of different environment, but mainly tending to be muddy. There should have been small-scale merchant shipping in the Jing river in historical period, but it is stopped for too many stones and sands in the river which is adverse to the shipping. The Jiaohuo Lake in the debouchure of Jing river gradually reduces from a wide range, and then falls into oblivion in the end.There are many water conservancy projects in the downstream area of the Jing river. The far-reaching Zhengguo Canal is built in the period of Qin state, and its continuous project——Jinghui Canal still plays an important role in the current time. The construction of the water conservancy projects in the downstream land of the Jing river come in succession in successive dynasties, but there's also creative development according to objective environmental changes. The construction of water conservancy projects reflects the development and vicissitude of the Jing river.Natural and anthropogenic factors have caused damages to the Jing river to varying degrees in the history. With the social development, the human beings gradually realize the importance of environmental protection. As an important element of the environmental factors, rivers should be contained in the scope of protection. The government has made orderly programmes for the protection and development of the Jing river.The vicissitude of the Jing river and human activities complement each other. When productivity is low, the vicissitude of the Jing river is mainly influenced by natural factors. With the raise of productivity, the influence of anthropogenic factors becomes the leading element. The vicissitude process of the Jing river reveals the influence of human activities to the changes and development of the relationship between human and nature, and provides us reference on rational use and protection of rivers.