北京市环城绿化隔离带生态规划

Ecological planning on greenbelt surrounding mega city, Beijing

研究运用生态规划方法、地理信息技术和遥感数据,在分析北京城市发展所面临的城市布局与生态环境问题,以及在规划范围内土地利用与生态环境功能的基础上,探讨了北京绿化隔离带的功能,提出了北京绿化隔离带的总体结构,景观格局与生态规划控制指标。研究表明:规划区内城镇建设用地已达4 0 .2 % ,现有土地景观布局零乱,各类开发建设活动十分活跃,扩张趋势明显,要保证足够的土地资源以发展绿化控制带的难度很大。绿化隔离带土地潜力和适宜性的评价结果揭示,如果能够严格控制城镇建设用地的进一步扩张,充分利用各类适宜性土地发展绿地,如林地、裸地、水体、耕地,重新规划分散的乡村居民点,释放一定的建设用地,则估计有6 5 .8%的潜力土地可发展为绿地。根据北京城市发展对近郊生态功能的要求以及规划区土地利用现状,北京绿化隔离带的总体结构应是楔型环城绿化隔离带,即沿交通干线贯穿绿带,中-小型生活社区与小城镇分布在绿化隔离带之中。绿化隔离带的景观生态格局应是以森林为基质、河流道路为廊道。

Regarding the importance of greenbelt functions for urban development, this article analyzes the necessity for developing greenbelt surrounding the mega city, Beijing. Due to more serious urban problems caused by fast urbanization, the major services or functions that can be fulfilled through greenbelt implementation are analyzed. They are: (1) to control urban unlimited sprawl and reactivate the Separate Centralized-Functional Group developing pattern. (2) to optimize urban landscape pattern and set up the large scale green linkage between urban center and far suburb. (3) to improve urban environment and strengthen ecological functions. (4) to limit industry development and evacuate urban central population. (5) to provide recreational sites for urban residents. Land suitability for green space development was studied based on the existing land cover/use distributed pattern. TM image was supported to extract the update land cover/use information. The research result showed various urban built-up areas occupied about 40.2% of the total planning area. Moreover, various human dominant activities were dense and urban expansion tendency was very clear within the belt zone. This makes it difficult to plan and implement a real and efficient greenbelt. If strict measures are taken to limit urban uncontrolled sprawl, make the best use of suitable land resource (forest, bare space, water body, and cultivated lands), centralize separate villages and release as much as possible lands to develop green spaces, at least 65.8% lands might have great potential to develop into green space. Therefore, the local governments and related urban planning departments need to establish sound land developing policies and efficient planning methods or steps, in order to guarantee the large-scale greenbelt plan coming into being. Based on greenbelt planning goals and the existing land cover/use development situation, the wedge-shaped pattern is conceptualized as the general suitable greenbelt structure. Separate distributed large green wedges, which would be filled with various green elements, would formulate the greenbelt' skeleton. Other non-green land patches, satellite towns, residential sites and industry, could insert within or between green wedges. “Green” corridors, transportation routes and rivers, would set the wide network to link the wedges and patches.