Assessment of regional vulnerability to seismic hazards in the Beijing–Tianjin–Hebei metropolitan area, China

Regional vulnerability research is helpful in understanding the formation mechanism of regional disaster risk deeply. Owing to the pressure from earthquake disasters occurred frequently in the whole world, the assessment of regional vulnerability to seismic hazards is a focus in current research of seismic disaster risk. This paper presents a nonlinear dynamic model for assessing regional vulnerability to seismic hazards based on maximum flux principle (MFP). Firstly, a vulnerability index system was designed for the urban agglomeration of Beijing, Tianjin and Hebei in China, and the index data were obtained based on the Statistical Yearbook and other materials. The vulnerability indexes constituted a complex system, and the indexes were taken as the components of the complex system. Secondly, based on the information theory and MFP, a dynamic equation that controls the generation and evolution of the complex system was derived theoretically. The regional vulnerability evaluation was realized by conferring reasonable weight to the indexes to make the system become stable. Finally, the self-organizing neural network was used to simulate the mechanism model to implement vulnerability assessment. The assessment results showed that Langfang and Chengde were at high vulnerability level; Qinghuangdao, Cangzhou and Zhangjiakou were at moderate vulnerability level; Baoding, Shijiazhuang, Beijing and Tangshan were at lower vulnerability level; Tianjin was at low vulnerability level. It reveals that the investment in disaster prevention was in an unbalanced situation among all the cities in Beijing–Tianjin–Hebei metropolitan area.