城市生态韧性时空变化及情景模拟研究——以杭州市为例

Abstract

从韧性的特征角度研究城市生态韧性水平的变化机制，探究城市防范化解生态风险能力的时空差异，以此明确城市分区生态治理的重要任务，是实现韧性城市生态风险防控的有利途径。从抵抗力、适应力和恢复力3个方面构建了城市生态韧性评估模型，并以杭州为例，评估了其1995-2015年城市生态韧性时空变化格局，再者利用空间自相关模型对2015年杭州生态韧性分区管理模式进行了探究。最后，基于FLUS模型模拟了2035年基准和创新创业导向的两种情景下的城市土地利用空间格局，并评估了不同城市发展情景下的生态韧性水平空间分布情况。基于以上研究得到以下结论：（1）1995-2005年，生态韧性低值区域向东北和东南方向扩张，而生态韧性高值水平区域明显减少。2005-2015年，杭州西北部和西部原本存在的中等韧性水平区域也转为低等水平。（2）2015年，城市东北区域呈现低韧性水平-高排污企业密度的集聚分布，说明该区域环境生态风险防范化解能力比较低，需要加大环境监测和生态治理的资金投入，严防重大环境污染事件的发生。（3）创新创业导向的"创新天堂"城市发展情景比基准情景下2035年杭州整体生态韧性水平更高，主要影响因素在于前者的抵抗力水平和适应力水平明显高于基准情景。研究结果为韧性城市生态环境发展提供了理论依据。;Resilience is defined as the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and recovering quickly. Among various methods, the zoning ecological governance provides us with a potentially efficient way to promote resilient city development by enhancing resilience abilities and preventing ecological risks in cities. Recently, resilient city construction has been a hot issue for many areas in China due to the frequent natural disasters and human-induced incidents. However, little is known about how to improve resilience from a zoning ecological governance perspective. It is therefore an effective way to realize the ecological risk prevention and control of resilient city by identifying the key task of urban zoning ecological governance via investigating change mechanism of urban ecologically resilient level in context of resilient characteristics and exploring the spatio-temporal differences of prevention and reconciliation capacity of ecological risks. This paper constructed an urban ecological resilience evaluation model from three perspectives, namely, resistance, adaptability, and restoring force. Then, taking Hangzhou as an example, we evaluated the spatio-temporal changes of urban ecological resilience from 1995 to 2015 and explored Hangzhou ecological resilience zone governance based on the spatial autocorrelation model. Finally, the study applied the FLUS model to evaluate the different spatial patterns of urban land use and spatial distribution of ecological resilience levels under the simulated benchmark scenario and Innovation Paradise scenario in 2035. The results show that (1) from 1995 to 2005, high-value ecological resilience areas decreased significantly, and low-value ecological resilience areas expanded to the northeast and southeast areas; from 2005 to 2015, the medium-value resilience areas in the northwest and west of Hangzhou turned to low-value areas. (2) In 2015, areas with low-value ecological resilience and high-value pollution enterprise density clustered in the northeastern parts, where the ability to prevent the environmental and ecological risks was relatively low. (3) The overall ecological resilience level under the Innovation Paradise scenario with a more compact urban growth mode was higher than that under the baseline scenario with extensive urban expansion. As such, there are some significant practical implications for the ecologically resilient construction of Hangzhou city. Firstly, it is suggested that local governments should strictly control the occupation of wetlands and strengthen the quality and quantity of ecological land, which can promote the balance of spatial difference of ecological resilience. Secondly, since there exists obvious spatial heterogeneity of ecologically resilient levels in Hangzhou, it is important to establish zoning management mode for a successful urban eco-environment governance based on precise grid control and regulation of eco-environmental risks. Thirdly, as to northeastern parts where gathered grids with low-value ecological resilience and high-value pollution enterprise density, it is urgent to transfer the high emission enterprises, accelerate the locally industrial upgrading, and strengthen the local monitoring level of ecological quality, which can reduce the local ecological risk and prevent the risk diffusion. Besides, green landscape development and compact urban development should be encouraged in the future urban planning of Hangzhou city. Finally, it is vital to establish a reasonably ecological compensation system within the city, which can help to re-allocate the resources including labor, technology, and investments among various districts and counties to guarantee the powerfully environmental governance and sustainable ecological protection.