The identification of vulnerable people and places to flood is crucial for effective disaster risk management. Here, we combine flood hazard and social vulnerability index to capture the potential risk of flood. In this paper, Nanjing was taken as the case study to explore the spatial pattern of social vulnerability towards flood at the community scale by developing an index system. Based on the flood risk results of ArcSWAT, the risk of flood disaster in Nanjing was evaluated. The results show the following. (1) Social vulnerability exhibits a central–peripheral pattern in general, which means that the social vulnerability degree is high in the central city and decreases gradually to the suburbs. (2) The susceptibility to flood disaster has a similar circle-layer pattern that is the highest in the urban centre, lower in the exurban areas, and the lowest in the suburb areas. (3) By using the GIS-based zoning approach, communities are classified into four types by comprehensively considering their flood susceptibility and social vulnerability. The spatial pattern is explained, and policy recommendation for reducing flood risk is provided for each type of community. The research has important reference significance for identifying the spatial pattern of social vulnerability to flood and then formulating targeted adaptation countermeasures.

With the acceleration of global climate change and urbanization, many large and medium-sized cities in China have been frequently subjected to heavy rains and floods. Thus, the question of how to reduce the impact of floods and achieve rapid recovery has attracted much attention. We use the urban community as the basic unit to examine the living environment, internal facilities, and surrounding environment characteristics of six different types of communities in the Jianye District of Nanjing City. First, we use factor analysis and the binary logistic regression model to analyze pre-disaster preparation, disaster response, and post-disaster recovery. Second, we analyze the resilience of the community at different stages. Then, we explore the influencing factors of the built environment on the resilience of the community. Results show that the built-up environmental factors, such as topography, riverfront, building coverage ratio, green space rate, and land use diversity, have a significant impact on community resilience. Finally, we proposed several suggestions for improving the flood resilience of Nanjing City.

China is vulnerable to climate change. Developing the ability to assess social vulnerability and inequality amid climate change will be imperative to ensure that adjustment policies can be developed for various groups and build resilient livelihoods in China. This paper examines social vulnerability and inequality through a joint analysis of urban agglomerations. Based on a conceptual framework of social vulnerability from a network perspective, the social vulnerability index of individual cities is quantified with a projection pursuit cluster model, the social vulnerability index of cities in urban networks is calculated with the Baidu Index, and an inequality analysis is measured by the Theil index. We pilot this study in three urban agglomerations: the Jing-Jin-Ji region, the Yangtze River Delta region, and the Pearl River Delta. Our results show the following: (1) The indicator of “GDP” with the weight value reaching 0.42 has the most influence on social vulnerability. Three indicators, which are fully described herein—“Children”, “Illiterate”, and “Higher education graduated”—contribute much to social vulnerability index with values between 0.3 and 0.4. These three indicators should receive more attention in integrated risk management. (2) In the Jing-Jin-Ji region, the Theil indexes of two indicators, “Ethnic minorities” and “Green”, exceed 0.65 and have the most influence on inequality. In the Yangtze River Delta, three indicators of “Poor”, “GDP”, and “Green” contribute much to inequality. In the Pearl River Delta, the inequalities of “Green”, “Houses with no tap water” and “Higher education graduated” are high. These indicators give advance warning of potential problems, so adjustment is recommended for reducing inequality. (3) Though the connectivity structure of the Yangtze River Delta is more complicated and stronger than that of the other two agglomerations, its inequality of connectivity is higher than the others. (4) Connectivity is key for reducing social vulnerability, on the one hand, but can result in more inequality of social vulnerability, on the other hand. Therefore, it’s crucial for government to attach more significance and provide more support to cities with a higher social vulnerability index.

Social capital plays a crucial role in enhancing community resilience during flood disasters. This study investigates the influence of social capital on community resilience in Nanjing, China. Social capital is composed of five aspects: cohesion, collective efficacy, sense of belonging, trust and reciprocity and informal social control. Factor analysis and multiple regression analysis are employed to analyze the dimensions of social capital and its impact on community resilience. Our results demonstrate that social cohesion and collective efficacy are the most representative factors of social capital. Reformed housing communities typically have higher cohesion than those in commercial and affordable housing. Affordable housing communities in flood-prone areas have higher collective efficacy but lower trust and reciprocity. Commercial housing communities have higher informal social control but have great internal differences in collective efficacy. We strongly urge government decision makers to enhance flood resilience by fostering social capital within local communities.