Quantitative Analysis of Coupling between Urbanization and Ecological Environment in Gansu Province

Through setting up index system of urbanization synthetical index and eco-environment synthetical index and using the coordinative degree model,quantitative analysis on the evolution trend of coupling between urbanization and eco-environment in Gansu province from 1990 to 2006.The results showed that: urbanization index and eco-environment index increasing linearly,the coordinated development index between urbanization and eco-environment fluctuated from 1990 to 2006,but the index showed a liner upward trend.From the curve of urbanization synthetical index and eco-environment synthetical index.It showed that urbanization lagged behind the development of the eco-environment before 2003,it leads to the coupling co-ordination has been mainly in low-level between urbanization and eco-environment.When the urbanization development reached a certain stage,the eco-environment will be improved,and the coupling relations between them can be gradually strengthened.