YANG Yong-chun, ZENG Zun-gu
Lanzhou is a typical valley-basin city in the northwestern China. This paper analyses the status quo's feature and organized model of internal structure and outer morphology of Lanzhou, and nodal region and homogenous area of urban district of Lanzhou. The factors affecting the forming and development of urban area structure of Lanzhou are discussed in the paper. Urban area structure of Lanzhou manifests dispersing and zonal multi-center spatial structure. Both of the homogenous degree and agglomerating degree of Lanzhou's urban district's functional area are very low. The average homogenous degree of inner and outer industrial area in Lanzhou's urban district are all below 1.07,and the average agglomerating degree of it are all below 0.27. The agglomerating degree of Lanzhou is below 0.03, which proves the belt feature of Lanzhou. The nodal region structure of Lanzhou's urban district still theoretically complies with Hexagon Structure Modal although the rank system of it isn't perfect because of the effect of natural conditions, especially landform.Lanzhou's unique natural condition and industrial development have played a great role on the development of its internal structure and outer morphology. Urban area structure of Lanzhou manifests dispersing and zonal multi-center spatial structure. The circle structure of urban area structure of Lanzhou from inner to outer place can be outlined as belted core parts, inner suburban district producing vegetables, melon and fruit in valley belt of the Huanghe(Yellow) River and the Huangshui River, outer sector satellite towns, outer agricultural area in the valley and others that concretely shows CBD commercial and serving center, fringe belt of urban center, inner and outer industrial area, satellite towns and agricultural suburbs. Fringe belt of urban center has the integrated function consisting of commercial function, social function, cultural function, administrative function, medical function, insurance function, financial function, and light industrial function. Inner industrial area includes Donggang, Yantan, Yanchangbu, Qilihe and Anning. The outer industrial area has Xigu, Liancheng-Haishiwan and Hekou-Dongchuan. There are cultivated land, lawn and tree land between the inner industrial area and outer industrial area. The satellite towns of Lanzhou have Yongdeng County town, Gaolan County town and Yuzhong County town. Now Lanzhou is one of the cities to be heaviest polluted in China because of its industry system whose key industry is oil and chemistry industry and limited polluted degree that urban air and water system in valley-basin can bear. Moreover, because the quantity of suitably urban land is limited urban reserve land will be lacked after twenty or thirty years according to the speed of consuming urban empty land. At the certain stage they are key problems to be solved in urban development that urban area structure should be rationally planned and the direction of its development should be carefully determined and satellite towns should be prudently selected after the sort of cities reach the certain higher stage. It is so important that urban area structure should be strategically adjusted, and independent districts should be rapidly established and satellite towns should be perfected in the process of valley-basin City's construction. In future, belted urban agglomeration would maybe appear in the upper reaches of the Huanghe River.
