城市可持续规划中的生态敏感区避让分析——以丽江市为例

为促进城市可持续发展,在科学合理规划城市空间格局的基础上,应突出强调保护原有特色生态环境要素,保育生态系统服务功能和原住民人居环境。作为世界文化遗产,丽江城市面貌在过去数十年发生了深刻变化,城市用地显著扩张,同时严峻的环境问题对城市可持续发展提出挑战。以丽江市为例,选取对其发展影响深远的水系元素、噪声环境因子和森林火灾3个关键生态敏感因子,提出通过分析这类生态敏感区在城市规划过程中的避让方法、程度,区划城市规划基本空间格局,以避免城市未来因生态环境问题突出而制约其发展的规划用地思路。结果表明,丽江城区周边湖泊水系、古城内部及周边原住民人口密集区都是保障城市可持续发展的生态保护重点地区,在城市用地规划中必须予以避让;该区域面积为147.2 km2,占研究区面积的11.1%。同时,明确给出了规划用地的具体空间控制范围和相应的避让原则。

Avoidance analysis in urban sustainable planning based on ecologically sensitive areas in Lijiang City, Yunnan Province, China

Urbanization is profoundly changing the sustainability of cities. On the one hand, the economy and society are developing rapidly, accompanied by an intense growth in the urban population that has exceeded growth in the rural population. On the other hand, urbanization is associated with a dramatic change in land use. The urban ecosystem and the surrounding natural ecosystem have been undergoing profound changes, some of which may undermine the foundations of the sustainable development of cities. The scientific and rational planning of urban spatial patterns is crucial in fostering the sustainability of cities. In planning procedures, emphasis should be placed on the maintenance of indigenous special eco-environmental elements, ecosystem services and the human settlement of indigenous persons, which are important to the sustainability of cities. As a famous tourist city and a world heritage site, Lijiang City has experienced a dramatic urban expansion during the last few decades. Meanwhile, it is facing many related environmental problems, including the degradation of riverine ecosystem services, noise pollution in the Old Town of Lijiang City, and forest fires at the wild-urban interface. All of these issues threaten the sustainability of Lijiang City. To maintain its sustainable development, this paper proposed an improved land planning methodology based on ecological sensitivity analysis. This would aim to prevent the city from future environmental problems, which would limit its development. By avoiding such environmental issues, an urban spatial pattern that aimed to ensure the sustainable development of the city could be developed. By analyzing the environmental problems of the city, the authors focused on three ecologically sensitive factors: namely, the water system, noise pollution and forest fires. Water is the soul of Lijiang City, and it is a distinctive ecological element. The condition of the water system is important to the integrity of ecosystem services and the normal operation of the city. With the development of tourism, the noise pollution in the Old Town of Lijiang City is becoming serious. It is closely allied to people''s wellbeing and a harmonious society. Urban expansion increases the area of the wild-urban interface, which may increase the risk of forest fires. This is related to the security of the city. So, all three factors are essential to the sustainability of Lijiang City. By considering the potential damage each factor may cause, this paper assigned a corresponding importance to each of the factors. The authors then zoned the ecologically sensitive areas and analyzed how-and to what extent-to avoid these areas in land planning. The results indicated that the most important areas for ecological protection and sustainable development were the lakes and rivers around the Lijiang basin, and the areas with high population density around, or in, the Old Town of Lijiang City. Thus the authors concluded that these regions must be avoided in urban planning strategy. The area of these regions was 147.2 km², which accounted for 11.1% of the study area. Meanwhile, 48.3% of the study area was of low sensitivity and mainly located in the northeast of the study area, surrounding the Lijiang basin and Yulong Snow Mountain. In addition, other limited areas for urban planning land were also identified and principles of avoidance were proposed accordingly.