Assessment of External Spatial Vulnerability of Mountain Cities under Climate Change：Zhao Tong Case Study, China

The assessment of spatial distribution of urban vulnerability enhances resilience planning. Vulnerability is closely related to resilience. The opposite of vulnerability is resilience, and the stronger the vulnerability is, the weaker the resilience is. As a description of the current situation of urban resilience capacity, the spatial evaluation results of urban vulnerability can provide an important scientific basis for urban disaster prevention and resilient city planning. However, many existing vulnerability assessments are not enough to support resilient planning under the impact of climate change. This paper discusses mountain cities of vulnerability in terms of analysis of human and environmental systems from application of the driver-pressure-state-impact-response (DPSIR) framework. Take Zhaotong, a typical mountainous city in southwest China, as an example. Firstly, defining the main types of natural disasters in the study area, including earthquakes, landslides and floods. Secondly, the method system of natural disaster assessment is constructed. Several indicators are taken into account, such as physical(related to the characteristics of buildings and terrain) and social indicators (related to population and economic income), as well as the accessibility from/to emergency services/hospitals. Indicators were processed by standardization, processed and correlated using the principal components analysis (PCA) and integrated within a Rough Analytical Hierarchy Process. Through the calculation, we can get the zoning of different levels of urban vulnerability. The results showed that the contradiction between human and land in the study area is more prominent, and the vulnerability of an urban center is higher than that of other regions, and the vulnerability of a central region is higher than that of northern and southern regions. Secondly, Zhaotong, as a typical highland mountainous city, is more vulnerable to high disaster risk areas in the urban fringe affected by climate change than other areas, while the areas with high population density and economic activity density have higher vulnerability. Finally, the corresponding elastic planning intervention is applied to the urban spatial units with different vulnerability characteristics. The DPSIR model was used to determine a management strategy to reduce the vulnerability of urban in response to drivers, pressures, states and impacts indicated by modelling. This research provides some implications for disaster mitigation and risk reduction strategies as well. Fund Item: Supported by the National Natural Science Foundation of China No.:51978050\The Science and Technology Program of Ministry of Housing and Urban-rural Development of the People's Republic of China No.: 2020-k-194