快速空间扩张下西安市边缘区社会脆弱性多尺度评估

Multi-scale assessment of social vulnerability to rapid urban expansion in urban fringe:A case study of Xi'an

社会脆弱性评估是解析社会脆弱性要素关系、量化社会脆弱性程度、识别脆弱空间单元或社会群体的重要途径,是实现社会脆弱性精准治理的重要依据。本文从外部扰动、内在结构、构成维度、尺度层级4个方面阐释了社会脆弱性概念内涵,并建立起社会脆弱性评估框架(SVAF),明确了社会脆弱性评价流程、评价目标、评价要素和数据方法,提出从暴露度、敏感性和适应能力3个维度构建社会脆弱性评价指标体系。在此基础上,以西安城市边缘区为例,视快速空间扩张为城市边缘区社会系统的主要扰动因子,开展多尺度社会脆弱性评价,得出街道、社区和农户3个尺度上的社会脆弱性空间(类型)分异结果。街道尺度上,低社会脆弱性街道占主体(48%),且多邻近市中心;社区尺度上,居住开发型社区社会脆弱性最高,教育功能型最低;农户尺度上,社会脆弱性以中等为主(52.7%),高社会脆弱性农户(17.5%)少于低社会脆弱性农户(29.9%)。随着街道—社区—农户尺度的下降,社会脆弱性指数的低值化集中趋势愈发显著,在农户—社区尺度之间,社会脆弱性指数等级对应关系相对明显,而其他两个尺度间并不显著。本研究可在社会脆弱性评价流程、评价指标体系、数据方法组织以及多尺度评价等方面为社会脆弱性评估理论研究与实践应用提供有益的探索。

Social vulnerability assessment is an important approach to analyzing the elements of vulnerability, quantifying degree of social vulnerability, and identifying vulnerable spatial units or social groups. Meanwhile, related policies addressing targeted management of social vulnerability are necessary. Therefore, we analyzed the concept and connotations of social vulnerability in four aspects, i.e., disturbance, structure, dimension and scale. We established a framework for social vulnerability assessment that defines the evaluation process, objective,elements, data and method. Based on this framework, we developed a common evaluation index system of social vulnerability according to the three dimensions of exposure, sensitivity and adaptive capacity. Finally, the social vulnerability assessment framework was applied to the case of the urban fringe of Xi＇an, which has undergone rapid urban expansion. Using a mix of qualitative and quantitative analyses, we combined data from a statistical yearbook, inperson interviews and household surveys and evaluated multi-scale social vulnerability. The spatial differentiation and types of social vulnerability were displayed according to three scales,i.e., Jiedao, communities and land-lost peasant households. The proportion of Jiedao with a low social vulnerability index was 48%. The social vulnerability index of communities requisitioned by housing estate was the highest, and the social vulnerability index was the lowest in the area of educational function. More than half of the land-lost households lay in the middle range of the social vulnerability index, with fewer households having a high index than those having a low index. With the decline of the scale from Jiedao to household, the low value distribution of the social vulnerability index changed from decentralization to centralization.Meanwhile, we found a significant correspondence at the level of the social vulnerability index between household and community, but not for other levels. Our research highlights the social vulnerability assessment framework involved in the evaluation process, index system, data organization, method and multi-scale assessment. These conclusions could be further explored for theoretical research and practical application of social vulnerability assessment.