Surface waves are formed close to the epicentre and can only travel through the outer part of the Earth’s crust. They are responsible for the majority of the buildings damaged by earthquakes.

Through field investigation and analysis, combining with historical earthquake documents, the causes of landform, rift valley and landslip relic of Xionger mountain is studied.

This composite and hierarchical index focuses on the spatial imbalance of the earthquake disaster risk within a megacity, and gives the relative risk level among the local areas of the city.