EFFECT OF LAND CREATION ON REGIONAL ECOLOGICAL ENVIRONMENT : A CASE STUDY FOR LANZHOU CITY , CHINA

With the accelerating process of urbanization, the contradiction between the shortage of land resources and the expansion of cities has become increasingly prominent. Many cities have expanded the area of development by “cutting mountains and building land”. Taking Lanzhou city of China, a typical valley-type city as the study area, land use change data obtained from remote sensing imagery in 1995, 2000, 2005, 2010, and 2015 were quantified by land use transfer matrix, land use change intensity index, ecosystem service value, and regional eco-environmental quality index method. The study on the characteristics of land use change and its impact on the ecological environment in Lanzhou City shows that the land use change in Lanzhou City during the period of 1990 to 2015 years is mainly reflected by the decrease of cultivated land and grassland, the increase in construction land and unused land area; The quality of eco-environment in Lanzhou City was negative developed from 1990 to 2015. The spatial expansion caused by urbanization had the most profound impact on land use types; the minimum value of eco-environmental index of all counties in Lanzhou City appeared in 2015, and Grassland and Farmland occupied by a large amount of construction land is the main reason for the deterioration of ecological environment quality. Based on the study, we expected to provide reference for the development and construction, and ecological environment protection of similar areas, especially the cities with extremely shortage of land resources such as the typical river-valley cities in the future development.