Study On Urban System In Zhangye Oasis Based On Fractal Theory

Urban system is a congregation constituted by different function,different scope interdependent cities in a relatively integrated area or country. water resource,terrain,traffic,mineral resource have a vital function for city development.oasis town is a crucial ecosystem in northwest endorheic drainage basin,which has a strong function on population,economy and culture in dry area.water resource restricted scale rank, function characteristic, spatial distribution,and ecosystem,urban develop speed and pattern.under the circumstens of global warming and water decrease,we should adopted a reasonable method to perfect urban system. Oasis city is the more centralize and susceptive region in arid area ,the ecology of arid area is very weak,the oasis survive or perish crucial is closely interrelated to the relationship between water and oasis ecology.Fractal thinking effective means to searching natural complexity,urban system distribution have obvious Non-sealing and rival staticfractal characteristic.portion can reflect some similar characteristic as well as unity. Fractal study in favour of geography quantification.this article select zhangye oasis act as study object,to combined town,oasis,water resource and population,industry,natural resources,to analysis urban scope,spatial aggregation and spatial interfunction,in order to probe into urban system optimize channel.Firstly,applied primicy ratio and fratal model to analys urban system scale,figure out scope dimention D=0.350,modulus R2=0.851,which indicated conclution of urban scope inattentive and primicy town in a monopoly position.Secondly,applied fratal model of to analys urban system spatial gather and spatial interaction,figure out spatial gather dimention D=1.224,modulus R2=0.9868,spatial interaction dimention D=1.4868, modulus R2 =0.9196,which indicated conclution of the small towns are the main scale rank,many towns are distributed by railway,highway and nationalhighway,city distribution pointed to water resource and traffic. spatial interaction feeble and town relationship are undertighten.which will bring to a disadvantages on urban accumulate effect,scale effect and so on.It is important for zhangye oasis to establish a reasonable city system to achieve a sustainable development of economy,society and environment.In order to perfect urban system in future we must abide by principally the"T"style in spatial distribution, and the"centre,axes and piece"to integreted style in spatial distribution, and firstly develop the towns with the good basis, continually perfect the traffic network, and what's more, reasonably exploit water resources and protect ecological environment. The purpose is to use fractal thinking to set up urban system and traffic network,to enable human to take advantage of finite geography spaceresources,to set up a reasonable urban layout,to formulate a region development strategy,to adjustment industry arrangement and industrial structure in region,to promote area economic development,to accelerate the development of eonomy,society and ecology in Heihe riwer.