Integrated assessment of urban safety of the cities in the mainland of China

City is an important foundation for human development. Natural disasters, whose impact on cities was influenced by disaster risk, urban vulnerability and resistance, have always posed serious threats to human development. It is important to identify the key factors in urban disaster preventing and urban securing to reduce the losses of disasters and ensure the urban safety. However, it is difficult to assess the urban safety comprehensively, as the characteristics of disasters and cities varied a lot, resulting in the limited efficiency of urban disaster prevention and management. As a result, we built an index system to improve the urban safety assessment method. By taking six types of urban disasters (urban flood and waterlogging, drought, low temperature, sandstorm, earthquake, and rockfall, landslide and debris flow disasters) into consideration, based on the open access data and the convenient methods to calculate weights and indices, this evaluation system is of applicability and simplicity, and it can overcome the low efficiency shortcoming of the current assessment methods. The index system was then applied to 596 cities in the mainland of China to validate its effectiveness and accuracy and understand the situation of urban safety of China. The interaction mechanisms among the three characteristics of urban disasters (disaster risk, urban vulnerability and resistance) were analysed qualitatively and quantitatively, and the 'compensate effect' between urban vulnerability and resistance was found. According to the result of the urban safety assessment, the safety situations of most cities in China were not satisfactory, but there was great potential to improve them. Since the major natural disasters and safety degrees varied in different cities, these Chinese mainland cities were classified into six different regions based on our results, and the key points of disaster management in each region were pointed out, in order to help the government to promote Chinese cities' safety.