Analysis On The Change Of Urban Construction Land Of Yanji City

Land as the carrier of people's life and production is an essential physical basis for social and economic development. The change land use structure is a result of synthetic interaction between nature and human, and is also an outcome of human-land system coupling. As for the land use structure changes, which is triggered by urbanization , the change of construction land is the most manifest.The rapid development of social economy will definitely promote the need for construction land. Experts believe that the reasonable value for the coefficient of elasticity in the urban construction land in China is 1.12. But due to the RS data, coefficient of elasticity in the metropolis of china is as high as 2.29. How to control the reasonable scale, and intensively use land is indispensable task to research in the urbanization of China.The data source of dissertation were the statistics data of Yanji construction land from 1996 to 2007 and the second land investigation data,. The dissertation took the method of georelational and statistics, and analyzed deeply the spatial pattern and proportional relation of construction land in Yanji in 2007, the change of construction land from 1996to2007, the increase source of construction land, and the factors of construction land social-economic benefit.The result showed construction land in Yanji increased 960.1hm2 in 12 years, the coefficient of elasticity of construction land is above 1.12,still reasonable. The increased value of construction land came from rural lands, especially from the cultivated lands. The construction land use of these increased value varied obviously. Industry use was dominant between 1996 and 2003, whereas communication use was dominant between 2004 and 2007. The tendency showed the support of land equiped the industry development and urban sprawl. The increase of construction land promote the increase of GDP. The construction land scale of 5000 hm2 is a key point for GDP change rate.The dissertation analysed the driving power of construction land increase to explore the support for the control of urbanization and scale reasonably. It is beneficial to the sustainable development for urban construction in China.