1995年以来中国中部城市不透水面增长变化监测及其增长模式研究——以南昌市为例

Reach on Chinese Central City Impervious Surface Area Growth Pattern in Recent 20 Years: Take Nanchang as a Case

以典型样地基准化法结合约束性线性光谱分解法对南昌市主城区1995年以来不透水面增长格局演变及其模式进行研究。结果表明:研究区不透水面格局呈"较散-集中-扩散"发展的总体规律,主导模式从"以轴线延伸式"向"以卫星填充式、零星飞地式增长"进行转变;格局变化与经济社会发展阶段演变、便捷技术及材料的广泛使用,地区土地政策、城市规划、城建投资等因素有关;制定理性的城市规划、重点关注郊区用地过快增长、推广使用绿色透水建材、透水的施工技术等可减缓研究区过快增长的不透水率。

Impervious surface Area（ISA） is an artificial surface as the specific components, mainly by the hard road, parking lot, a square and a roof and other buildings composition in the city. Because isolation of surface water infiltration into the soil, impervious surface can cut the urban surface and subsurface hydrological connection. It is regarded as important elements on process of urban hydrological cycle, thermal cycling, local climate and biodiversity changes, has become an important indicator of urbanization healthy and quality of the city growth. So it increasingly becomes a hot research issues in geography, ecology, urban planning, environmental science and remote sensing information in recent years in China. But the long-term monitoring and longitudinal comparison of impervious surface is a challenging work. Based on the exited correlation between typical samples＇ impervious rate, an innovation research method that we called it Reference model of Typical Samples（RTM） was constructed and used to do comparison of impervious surface in historical yearin this article. Besides, the paper examines the impervious surface area growth pattern in recent 20 years in Nanchang main urban areawas applying of Constraint Linear Spectral Unmixing Method（CLSUM）. This study shows that the overall development shows the impervious surface area percentage（ISP） increases obviously in Nanchang main urban area in recent 20 years with the percentage of annual increase on 0.09% and the area of annual increase on 32 hatches. The growth pattern shows＂decentralized-concentration-diffusion＂expanding mode in study area, with the transition of impervious surface high-growth area from urban centers to urban fringe district. The preexisting dominant＂road extending＂developing mode is gradually transformed into＂Satellite filling＂mode and＂Sporadic enclave＂mode, with its contribution of ISP from 23% in 1995 to 11% in 2014 and at the same time Satellite Sporadic enclavemode contribution to study area ISP from 63% to 71%. From the macro view, the impervious surface pattern evolution was affected by the development of social economy and the spreading of convenient engineering technology and materials. On the micro level, this kind of surface changing is also impacted by land policy, urban planning and the investment of urban construction, et al. The present study found that the excessive growth of impervious surface can be effectively reduced by： 1） Rationally planning city expansion; 2） Paying more attention to the excessive growth of construction land in suburban areas; 3） Promoting the use of green permeable building materials; 4） Developing the new construction technology used for improving permeability. The before-and-after comparison of the impervious surface pattern can be unified into a bench mark by joint applying of RTM and CLSUM, with elimination of certain errors. So the reference model of typical samples lays an analyzing foundation for the long-term monitoring and comparing of urban impervious surface changing.