Study On Extension Of Urban Construction Land-Use Of YiChun City

Urban construction land extension is one of the most remarkable characteristics of urbanization. Besides the centralization of population and economy, the process of urbanization emphasizes on the course of regional space extension in particular. Studying urban construction land extension can not only deepen the understanding of the essence of urbanization, but also provide effective decision basis for the sustainable development of urban.Yichun city, which is located in the northwest of Jiangxi province, is the central city of western Jiangxi region. Based on the previous achievements, this thesis using the inner city and surrounding areas whose range is totally 235.74 square kilometers as the researching zone analyzes the alteration characteristics of urban land-using spatiotemporal extension, studies dynamic mechanism of urban land extension evaluates the surrounding areas of construction land suitably and predicts appropriate direction of urban land extension. There are several main achievements as follows:(1)According to the expending speed, it divides the urban land extension into three stages, that is stable extension stage, slow extension stage and fast extension stage. It also applies area intersection analysis of spatiotemporal analysis module with MAPGIS to get the information that in the process of urban land extension, the main occupied land types of Yichun city are cultivated land and forest land during 1992-2007.Futhermore, it comprehensively uses some modules such as dynamic degree of single land-using type, intensity index of land extension and land alteration to do research into structural characteristics and differentiation regularity of land alteration in the researching zone with the result shows that construction land is the most actively changing land type. During these 15 years, it has increased 1949.13 hectares with 58.57 percent amplitude among which urban land extension is 665.11 hectares, intensity index of land extension in annual average is 0.188, dynamic degree of single land-using type is 2.92 and index of variation degree is 2.07.(2)It extracts urban land range within three periods by TM/ETM Image and makes others get to know the two expending directions (NE-NNE-NEE and SSW-S) of Yichun city's land extension by using 16-orientation equal fan analysis. Moreover, it analyzes the evolution characteristics of urban external shape by compact ratio and fractal dimension to draw a conclusion that the development model of Yichun city's land extension in recent ten years takes filled inside as the major and expending outside as an assistant.(3)It analyzes the driving force of urban land extension in Yichun city by qualitative and quantitative analysis. Within quantitative analysis, it chooses built-up area for years as the dependent variable and the main component value of population, economic output value, people's life and transportation as the independent variable to make a stepwise regression analysis and obtain the expression. Through qualitative analysis, others can get to know that urban land extension of Yichun city is mainly related to some factors, such as geography, economy, population, transportation and policy.(4)With the help of GIS, it makes suitable evaluation to surrounding arrears of Yichun city's built-up area by multi-factor comprehensive evaluation method which shows that the suitable construction land is distributed mainly in the north and east region.(5)It adopts a multi-objective catastrophe model to make a quantitative evaluation on three extension plans including eastern, southward and northward extension. And the result shows that northward extension can be the main direction with eastern extension to be vice-important. For southward extension, the assistant direction may be better.