城市滑坡灾害生态风险不确定性分析及风险管理——以深圳市为例

城市化的快速推进加剧了建设活动强度,强烈改变自然地表,破环原本稳定的地质环境,导致滑坡灾害日益频繁。本研究以深圳市为研究区,基于"危险性-脆弱性-潜在损失"三维评价框架评价深圳市街道尺度滑坡灾害生态风险、运用"三基色"原理可视化风险结构,并采用蒙特卡洛模拟进行不确定性分析,进而提出生态风险管理措施。结果表明:(1)不确定性与街道面积呈显著的负相关关系,随着街道面积增加,生态风险源不确定性减少;(2)以风险源为不确定性主体的生态风险评价中,不确定性由生态风险源不确定性和"源外"因子大小共同主导,"源外"因子大小是生态风险评价不确定的敏感因素;(3)深圳市滑坡灾害生态风险从西到东呈现"低-高-低-高"交错结构,风险结构主要为"高脆弱-高潜在损失"型和"高危险-高潜在损失"型。分析生态风险结构,建立滑坡灾害生态风险管理体系,制定明确风险管理目标,有利于高效地进行生态风险管理。

Uncertainty analysis and risk management of ecological risk of urban landslide disaster: a case of Shenzhen City

The rapid urbanization along with intensive construction activities, strongly changes the natural landform and the stable geological environment, which leads to increasingly frequent landslide disasters. Taking Shenzhen as the research area in this study, the ecological risk of street scale landslide disaster was evaluated based on the three-dimensional evaluation framework "Risk-Vulnerability-Potential loss". The visual risk structure of "three primary colors" was applied while the uncertainty analysis was carried out by Monte Carlo simulation. Then the ecological risk management measures were proposed. The results show that: (1) There was a significant negative correlation between the uncertainty and the evaluation area. As the evaluation area increased, the uncertainty of ecological risk sources decreased. (2) For the ecological risk assessment where risk source is the main uncertainty, the uncertainties are jointly determined by the ecological risk source uncertainty and the value of the extrinsic factor which is the sensitive factor of the ecological risk uncertainties. (3) The ecological risk of landslide disaster in Shenzhen presents a structure of "low-high-low-high" from west to east. The risk structures are mainly of the "high vulnerability-high potential loss" type and the "high risk-high potential loss" type. The analysis of ecological risk structure, the establishment of an ecological risk management system for landslide disaster and the development of clear risk management objectives are conducive for the effective management of ecological risk.