Integral Urban Spatial Forecast Of Dunhuang City Based On SLEUTH Model

Dunhuang is a county-level city in Gansu,Jiuquan Province,located in the west end of the Hexi Corridor,located in Gansu,Qinghai,Xinjiang three provinces(districts)interchange.where the average slope of the region is low,suitable for urban development needs.On September 7,2013,Chinese President Xi Jinping presented the concept of "Silk Road Economic Belt" at the University of Nazarbayev,Kazakhstan.Dunhuang City as an important node of the Silk Road economic zone and has a special position of the first hub of the ancient Silk Road.Dunhuang is not only a city of agricultural development,but also the world's historical and cultural city and the world's tourist city.With the economic development of Dunhuang City,the population growth,the rate of urban space expansion will accelerate.Based on the previous research,this paper uses the SLEUTH model to simulate the urban spatial expansion of Dunhuang City in the historical period,so as to predict the future spatial expansion of Dunhuang City.This paper first collected Landsat TM / ETM + remote sensing images from Dunhuang City in 1990,1996,2006 and 2015,and Dunhuang City Planning.The GIS method is used to delineate the urbanization layer and the traffic road layer,extract the Dunhuang slope layer and shadow layer.By simulating the urban spatial expansion of Dunhuang City from 1990 to 2015,the five different coefficient values??needed to obtain the SLEUTH model are obtained.Finally,based on the actual situation and combined with the results of predecessors,we set up four different exclusion layer.Different exclusion layers correspond to different prediction schemes.Under the free extengding forecasting scheme,the urban spatial expansion process of Dunhuang presents a disordered trend along the development of traffic roads at all levels,which is huge in the surrounding natural environment,occupying a large area of ??urban surrounding farmland,green space system,At the same time,it also has great damage to the natural landscape of Dunhuang,which is not conducive to the reasonable,orderly and healthy development of Dunhuang;under free extengding,through the green space,ecosystem and farmland Set a higher gray scale,so that the probability of urbanization can be reduced.Which will play a protective role in theprocess of spatial expansion of Dunhuang City,and protect the ecological environment of the city.Under the plan of cultivated land protection,when set the exclusion layer,the farmland system can limit the development of the city to the maximum extent,so as to reduce the proportion of the urban development to the farmland.Under the guidance of planning and development programs,The local government ecology,farmland protection awareness has been strengthened,but for the local development of the actual needs,on the basis of comprehensive consideration,the green farmland have been Take up.The forecast results indicate that the future development of Dunhuang City should be mainly guided by planning and guidance,supplemented by environment-friendly,cultivated land protection program.On this basis,the paper explores the driving forces of urban spatial expansion in Dunhuang,and finds that the most fundamental driving force for the expansion is the rapid development of economy and the increase of population.