基于景观生态过程分析的城市综合生态风险评价——以两岸典型城市为例

Urban landscape is a kind of complex social-economic-natural ecosystem. Natural and physical elements are its primary components, economic activities and metabolic processes continue and evolve, and human needs drive its succession and evolution. A city does not exist independently and is composed of many subsystems with specific structures and functions. The ideal urban landscape is harmonic, efficient, continuous, and with a reasonable set of structures and relationships. .Ecological risk Assessment is becoming increasingly important because of severe pollution and ecosystem degradation, including air pollution, water pollution, soil loss and degradation, desertification, decrease in forest cover, the greenhouse effect, destruction of the ozone layer, and decrease in species diversity. Various and complex ecological risks occur widely in urban ecosystem. Conventional assessments for single types of ecological risks are not comprehensive enough to evaluate the degree of ecological risk, and are also unsuitable to meet the multiple needs of sustainable urban development and management. .In this research, a framework has been formulated to evaluate urban ecological risks more comprehensively and spatially, and the cities along the eastern coast of mainland China and western coast of Taiwan have been evaluate urban ecological risks based on analysis of urban ecological processes. First, four primary urban ecological risks have been identified, including global change, complex disasters, human activities, and the background of natural environment are considered. The temporal and spatial characteristics analysis of urbanization processes integrated remote sensing remote sensing image data, current status investigation of landuse, and other statistical data from government departments. Quantification change tendency of ecological services and degree of urban ecological risk. Single and comprehensive ecological risk degrees have been calculated. Based on these, spatial strategies of urban ecological planning are proposed that incorporate these assessment results. .Due to the differences in natural background conditions and development orientation, there are also some specific problems existing in the urban development of mainland China and Taiwan. For a long time, urban development in Taiwan has been heavily affected by physical restriction, especially geological and meteorological disaster as well as sea levels rise; in relative terms, cities in mainland China have been beset with more problems from various environmental pollution and degradation. Since sustainable urban development is required to complement the advantages and learn each other’s experience, comparison on urban ecosystem functions among the typical coastal cities could provide policy makers the reference for planning urban development in the future.

城市景观是人类生存与发展的主要载体，也是抵御与适应全球变化风险冲击的主体之一，由于高密度及高强度的人为活动提升了对城市各项风险保障的需求，综合评估城市发展中面临的各项生态风险，成为城市可持续发展需要考虑的目标。有鉴于当前城市主要生态风险源于气候变化、综合灾害、人为活动及资源环境本底特征，本研究拟通过近30年两岸沿海城市遥感影像、土地利用数据及统计数据，分析城市景观生态过程时空动态变化，其中景观生态过程选择以城市化为主轴，并分析其由于城市景观格局演变产生的生态服务功能变化及相应的负面生态环境影响及复合型灾害的危害。其次选择台湾地区及大陆珠三角地区主要城市为典型研究区，比较两岸城市化过程所衍生的城市生态系统服务功能、社会经济现状及环境资源质量差异。进而由人为活动、自然灾害及环境问题三方面构建城市综合生态风险评估框架，探讨典型城市生态风险类型与不同风险间的相互作用关系，尝试提出应对的策略。

城市化是人类文明的基本特征也是当前人类社会最显著的生态过程之一。近年来快速城市化压缩了城市发展的时间历程，加剧了生态环境问题的影响程度，衍生出水土流失、生境破碎、环境污染及生物多样性降低等生态环境问题与风险。.有鉴于此，项目围绕城市地区的生态过程、生态风险、景观格局等议题，选择台湾地区与深圳市为主要研究区，开展基于景观生态过程分析的城市综合生态风险评价研究，期望通过量化两岸城市化过程中社会经济、资源环境与景观格局间的变化趋势与相互作用，探讨城市区域的主要生态风险类型及影响，构建城市综合生态风险评估框架。.研究内容主要分为4个部分：(1) 两岸城市发展背景及格局演变；(2) 城市景观生态过程及其影响机理；(3) 城市生态风险识别及其时空效应；(4) 城市综合生态风险评价。.项目整理、收集了台湾地区及深圳市城市发展过程中社会、经济与资源环境基础数据；由人类活动视角，系统地分析了台湾地区及深圳市城市发展过程对资源环境造成的冲击及相互作用，估算过程中尝试加入城市环境设施的净化功能，可为当前客观评价城市化影响提供一定的参考；项目将城市生态风险归纳为自然灾害、环境污染及人口负荷三种主要类型，综合城市地区社会、经济及自然背景特征，基于时间和空间变化分析，分别构建城市综合生态风险评估框架，对现有的景观生态保障方案进行评估，进而提出城市生态风险防范建议。.通过归纳研究结果，有助于明晰我国沿海地区城市生态风险研究的核心问题：(1) 城市化过程存在的生态风险类型、影响因子及其相互作用；(2) 如何构建基于时间过程与空间格局演变的城市生态风险评估框架。研究成果可为我国城市地区生态风险防范与景观格局优化提供空间分析方法的参考和风险评价理论支撑。