关键词: 城市空间, 扩展特征, 驱动因子, 济南市

Abstract:

Urban spatial expansion is the external mapping of urbanization process, urban external form and spatial structure change. The study of urban spatial expansion, especially the urban spatial expansion in the rapid urbanization stage, can help reveal the characteristics, rules and driving mechanism of urban spatial evolution, and provide theoretical basis for urban planning and construction. Based on Landsat remote sensing image data of Jinan in 1992, 2000, 2010 and 2018, ArcGIS and ENVI image analysis tools were used in this paper.This paper by extracts the built-up area of Jinan city, explores the spatiotemporal change process and characteristics of the spatial expansion of Jinan city from the aspects of expansion speed, intensity, fractal dimension, compactness, and center of gravity transfer. From the aspects of natural location and social economy, factors that may affect urban space expansion are selected, The study analyzes the driving force of the spatial expansion of Jinan by using the geographic weighted logistic regression.The results show that: 1) The urban space expansion in Jinan experienced three stages: ‘medium-strength and low-speed’, ‘high-strength and medium-speed’, and ‘low-strength and high-speed’, The external shape of the city tends to be stable, and the urban shape presents a strip pattern of east-west distribution with poor compactness. 2) Jinan urban space expanded most significantly towards E, NEE and NE in 1992 to 2018. The expansion mode was dominated by extension expansion and internal filling, and the center of gravity of urban spatial distribution shifted significantly to the east. 3) The spatial expansion of Jinan is affected by multiple driving factors, the main driving factors are distance from the built-up area of the city, distance from the main highway, Gross Domestic Product, urbanization rate, population density. The driving mechanism of each main driving factor is different.The closer the area is to the urban built-up area, the higher the radiation degree of urban social and economic activities will be, and the urban space expansion will be more likely to occur. The construction of transportation infrastructure is conducive to increasing the intensity of land development along the routes, accelerating the process of urbanization, accelerating the expansion of urban space, improving the efficiency of resource allocation and driving the development of surrounding areas. To some extent, the economic development of Jinan depends on the input of urban land resources, which have higher land use value and actual output capacity. The agglomeration of population increases the bearing pressure of urban space in Jinan, and urges the city to expand its own space to meet the land demand brought by the increase of population density. 4) Compared with other provincial capitals, Jinan has a relatively small scale of urban space expansion and has not yet formed a multi-center urban space structure. The centrality of the eastern and western urban areas is not obvious, and the central urban area bears great pressure, the effect of ‘northern span’ is not significant. In the future, Jinan needs to build an urban spatial structure of ‘group layout and multi-center support’ on the basis of the existing strip spatial expansion.

Key words: urban space, extended features, driving factor, Jinan City