南昌市中心城区城市建设用地集约利用特征及空间相关性分析

城市化进程不可避免的要占用大量土地资源,当前城市土地集约利用已经成为地理学、土地科学等相关学科研究的热点问题。为了从中观尺度科学分析城市土地集约利用空间分布规律和趋势,以南昌市中心城区为研究对象,在城市建设用地集约利用评价的基础上,运用全域Moran's I和局域Moran's I系数分析建设用地集约度的空间自相关格局(依赖性),揭示建设用地利用集约度的空间局部聚集和局部异常特征。结果表明:建设用地利用集约度全域空间相关性和局域空间相关性指标均显著,从城市边缘到中心区(或副中心)呈现递增的空间形态,其中居住功能区集约度空间相关性最高,教育功能区则最低;各功能区都存在正局域相关,空间分布呈现典型的空间聚集现象。对于高值聚类区应以结构挖潜为主,通过旧城改造和用地置换优化用地布局,低值和高低值聚类区应以管理潜力挖潜为主,通过规划管理和政策引导提高集约度,达到经济社会生态效益相统一的目标,可为南昌市城市建设用地集约利用提供必要的支撑和依据。

ANALYSIS ON THE CHARACTERISTICS AND SPATIAL CORRELATION OF URBAN LAND INTENSIVE USE IN NANCHANG CENTRE AREA

Global urbanization has been accelerating since 1990s. In China, the urbanization level increased to over 50% in 2011. Along with economic growth and urban population explosion, human's disturbance on natural landscape is unprecedented, threatening national policy goals of arable land protection and environmental conservation. Thus, urban land intensive use has become a research hot spot in the field of Geography and Land Sciences. In this paper, based on the results of intensive land use, the spatial correlation of each urban function areas such as commercial, industrial, educational and residential are found out using global and local Moran's I index. The results showed that the area of moderate intensive land use accounts for 75.4% of the total area. The intensive use level decrease along with the distance to urban centre. There exists a high spatial correlation in each function area either in global or regional level. In global level, global Moran's I of each functional areas are greater than 0. It was discovered that residential function area has the strongest spatial correlation while educational function area has a weak correlation. Living functional area is the strongest, with an I value of 0.74 and the highest score of 163.73. They have similar values in the surrounding elements (higher or lower value). The main reason is that living area occupies the dominant position, supporting infrastructure complete, easy to form a neighbourhood effect. The industrial zone ranked second, with an I value of 0.62 and Z value of 8.48. The industrial park, economic and technological development zone, hi tech industrial park have strong correlation with each other. For the commercial district, the I value is 0.52 and the Z value is 7.68. City commercial land and residential land are close to the old city, so they are Gathered easily. In local level, there exists a positive correlation among function areas and presents an spatial aggregation characteristics. The high value of the clustering (HH) is mainly concentrated in the old city center area, with higher intensive degrees. Low value clustering (LL) is mainly distributed in the periphery of the old urban areas, which are comprehensive modern residential with complete infrastructure, but low occupancy rates, and low population density. Commercial and residential areas have high value of clustering, and industrial and educational function areas have low value of clustering. We argue that the areas with high value of intensive degree should adjust the structure of land use through the old city reconstruction and land replacement and the areas with low value of intensive degree should formulate a policy guidance to improve intensive degree. This paper is expected to support the urban intensive land use of case study area both in theoretical and practical means.