The Study On Land Use Patterns Based On Gravity Modelin Urban Economic Circle Of Lanzhou-baiyin Area

Attributing to the economy regionalization and urbanization, the convergency level of economy has been continuously increasing, and regional economic integration has become the main trend globally in foreseeable future. The pattern of regional economy development would be clustering development, combining joint of economic belt and industrial belt, importance of central city is becoming more obviously, thus city and city-group based economic circle becomes main stream. Rapid urbanization leads more dependence on land utilization, meanwhile rareness of land makes urbanization unsustainable. Especially in the process of urbanization, cities takes cultivated land, this draws people’s attention on optimization of land utilization, from aspect of economics, sociology and ecology.This paper study the land use pattern of Lanzhou and Baiyin economic circle by using the gravity model, and the result of the study indicate that:(1) The Lanzhou’s gravity value is 0.833, with the absolute advantage, and the Baiyin’s is 0.008. Thus it is not need to consider the two central cities which means the “double gravity” is not exist. In terms of the districts and counties, chengguan district’s gravity value is 0.908 which is the biggest value, and its gravity value is far bigger than the anning district’s value which is located in the second. So is the qilihe district and xigu district, the third one and the forth one. That means the gap between the baiyin district, with the value of 0.080, and the xigu district is so large. Besides the gravity value of the last area, jigntai country, is just 0.037. It show that the greater the the strength of gravity, and the shorter the distance, the stronger the gravity. From the perspective of the distribution of index it is in conformity with the trend of urban development, some areas of development potential is bigger(such as: anning district, silver area), but ome areas should change its development mode or adjust structure(such as huining, jingtai county).(2) According to the breaking point location and spatial location, the space function of lanzhou and Baiyin economic circle can be divided into three areas which are strong area, medium area and weak area: strong gravitational area, namely the breaking point location < 0.20, contains 4 districts of lanzhou city which are chengguan district, qilihe district, xigu district, anning district; medium gravity area, 0.20 < breaking point position<0.70, including 3 districts and 3 counties: baiyin district, honggu district, pingchuan district, yongdeng county, gaolan county and yuzhong county; Weak gravity area, 0.70 < breaking point position. The influence of Lanzhou is weak to these areas, including huining, jingyuan, jingtai county.(3) In view of the different gravity field and the present situation of land use, someone puts forward the corresponding land use patterns, Namely to establish the central city with the resource-efficient environmentally friendly mode, to establish the science and technology industry aggregation mode with the anning district as the center, to establish the industrial base model with gaolan country as the center, to established agriculture and ecological tourism mode with yuzhong country as the center, to establish the three-dimensional traffic patterns which can connect the small area. Land, as a kind of limited resources, how to reasonable distribution will influence the effect of the construction of the whole economic circle. And an important problem is how to divide its by the ratio between the land for construction and ecological environment.(4) According to the existing land use pattern of lanzhou and Baiyin economic circle, this paper put forward the corresponding suggestions on the development of the future: Perfecting the market mechanism, breaking the regional segmentation. Building a regional industrial cluster innovation supporting system. Speeding up the development of supportive services in the economic circle. Strengthening infrastructure construction, establishing a network system of collaborative industry division of labor. Because of the land use of economic circle is in a dynamic process, the size of the impact strength is also changing, so we should take continuous tracking and attention.