长江中游大城市不透水面增长模式及其驱动因素

Study on a model of water surface growth and its driving factors in large cities along the middle reaches of the Yangtze River

以1995、2003、2010、2015年4期遥感影像数据为基础,对武汉、长沙、南昌为例的长江中游城市20年不透水面增长及驱动因素进行研究。结果表明,三城市不透水面增长显著,接近预警水平,格局呈突围扩张的基本态势;现阶段武汉不透水面主要为城郊面源"零星"增长模式贡献较大;长沙、南昌则主要来源于新城"线式"延伸及其内部"面式"填充模式;道路投资、区划政策、城市规划控制、固定资产投资、房产投资、人口增长、透水技术等是影响三城市不透水增长的主要因素,但各因素影响敏感度在三城市中又有差异;三城市可从强化城乡规划的管理措施、控制过热的房地投资经济政策措施、平衡区域人口格局的社会政策措施以及推广透水材料和技术的科技措施等方面来缓解不透水率的增长。

Based on remote sensing image data for 1995, 2003, 2010, and 2015, the different growth patterns of impervious surfaces in China＇s cities of Wuhan, Changsha, and Nanchang over the past 20 years were studied using classical linear spectral analysis VIS model, ArcGIS hotspot analysis, and least squares linear modeling. The results show that The impervious surface areas （ISAs） of the three cities increased obviously, showing a regular pattern of expansion. The impervious surface rate of Wuhan, Changsha and Nanchang in the greenbelt surrounding area has reached 8.9%, 7.9%, and 7.4% respectively, which are close to the internationally recognized early warning level of 10%-20%. The three cities＇ ISA growth from the old city to the surrounding area gradually spread, which the city of Wuhan has broken through the greenbelt by ＂sporadic＂ increasing and the cities of Changsha and Nanchang are from the ＂point ＋ line＂ to ＂surface＂ ISA growth pattern transition stage, also presents the breakthrough greenbelt trending. Because of the influence of city development stage and historical conditions, impervious surface growth in Wuhan arises mainly from the sporadic growth of suburban areas. Expansion in Changsha and Nanchang is mainly due to ＂axis ＋ block filling＂ extension growth of newly developed areas. Road investment, zoning policy, urban planning control, fixed assets investment, real estate investment, population growth, and water penetration technology are the main factors that affect the impervious growth of the three cities, but the sensitivity of each factor differs among the cities. For Wuhan, the priority policy for reducing the ISA rate is to control the out greenbelt space, which can be strengthened via a rural construction planning permission system. Secondly, applying advanced technology to the greening transformation of the old city, reducing the density of real estate construction and infrastructure investment, optimizing the population density distribution, and balancing the city population with the city ecology can also alleviate the ISA growth trend. For Changsha and Nanchang, the primary method to controlling ISA increasing is to control the undeveloped areas in the inner greenbelt zone. The guiding principles of ＂precise controlling new area＂, ＂preventive controlling the suburbs＂, and ＂enhanced controlling the old area＂ should be applied to avoid expanding the ISA pattern. On the other hand, it is important to improve ISA by including smart urban and rural planning, increasing the rate of green space planning, balancing the population of districts, advocating the profit priority construction of urban infrastructure, and accelerating the use of advanced permeable materials and construction technologies.