基于生态适应性循环三维框架的城市景观生态风险评价

本研究以城市社会—生态系统为风险评价对象,引入生态适应性循环三维框架,将景观生态风险评价指标从单一的景观指数层面扩展至“潜力—连通度—恢复力”三维准则,并以深圳市为研究区,基于有序加权平均（OWA）算法对评价结果进行情景设置。研究结果显示,评价中干扰指标主要影响风险评价结果属性值域,而风险空间格局则受暴露指标制约;深圳全市景观生态风险整体呈现“西高东低”的分布格局,城市新建成区风险最高,大鹏半岛风险最低,羊台山与笔架山公园则是城区内部的相对风险低值区;基于OWA方法设置情景偏好,绘制“忽视”、“正常”及“重视”三种风险情景下的城市景观生态风险图。本研究基于生态适应性循环理念集成社会—生态系统时空动态干扰与暴露指标表征城市景观生态风险,并通过OWA方法变换主观偏好、降低评价不确定性,可以满足不同发展思路下的城市开发布局需求,从而为城市景观发展空间权衡提供决策支持。

Urban landscape ecological risk assessment based on the 3D framework of adaptive cycle

As the city social-ecological system was regarded as the risk assessment target, a 3D framework of ecological adaptive cycle was built, which extended the landscape ecological risk assessment indicators to the potential-connectedness-resilience 3D criteria from the former landscape index level. Emphasis was placed on the principle of static spatial pattern with interactive dynamic trend from a geographical spatial analysis view. It was believed that the 3D framework could describe the pattern-process interaction with specific landscape elements much more clearly. Taking Shenzhen city as a study area, this study adopted the 3D framework of ecological adaptive cycle in building a landscape ecological risk assessment index system with the help of GIS spatial analysis method. Different scenarios were established based on the ordered weighted averaging (OWA) algorithm in the risk assessment. The results show that among the three scenarios, the concrete value of landscape ecological risk showed a similar distribution trend that the Dapeng Peninsula had the lowest landscape ecological risk in Shenzhen city; Yangtai Mountain and Bijiashan Park showed relatively low risks in the city area, even though the risks in each scenario were specifically different. This indicated that the choice of the specific threshold in "development" or "protection" largely depended on the city development strategy created by decision makers under current cognition. The emphasis of scenario tradeoff was extracting the risk and uncertainty interval rather than an optimal value. The development or protection methods through each of the specific planning objectives would be the ultimate goal of the ecological risk assessment at a regional scale. The evaluation in this study improved the landscape ecological risk assessment indices and methods based on the adaptive cycle concept, which reflected the spatiotemporal dynamics and exposure disturbed by human interference. Furthermore, the preference transform in OWA method reduced the uncertainty caused by the subjective risk assessment, which could improve the theoretical basis as well as maneuverability in urban planning. This study not only extended the landscape ecological risk assessment to spatial-temporal integration perspective, but also made a significant improvement in ecological risk assessment of landscape indicator system. Therefore, the results of this study could offer a powerful quantitative support for landscape development and protective measures effectively, such as city construction and demarcation of ecological control line.