The Enormous Challenge faced by China to Reduce Earthquake Losses

Abstract:

In past six years, several big earthquakes occurred in Chinese continent that have caused enormous economic loss and casualties. These earthquakes include the following: 2008 Mw=7.9 Wenchuan; 2010 Mw=6.9 Yushu; 2013 Mw=6.6 Lushan; and 2013 Mw=5.9 Minxian events. On August 4, 2014 the Mw=6.1 earthquake struck Ludian in Yunnan province. Althought it was a moderate size earthquake, the casualties have reached at least 589 people.

In fact, more than 50% of Chinese cities and more than 70% of large to medium size cities are located in the areas where the seismic intensity may reach Ⅶ or higher. Collapsing buildings are the main cause of Chinese earthquake casualties; the secondary causes are induced geological disasters such as landslide and barrier lakes.

Several enormous challenges must be overcome to reduce hazards from earthquakes and secondary disasters.（1）Much of the infrastructure in China cannot meet the engineering standard for adequate seismic protection. In particular, some buildings are not strong enough to survive the potential strong ground shaking, and some of them did do not keep away from the active fault with a safe distance. It will be very costly to reinforce or rebuild such buildings. (2) There is lack of the rigorous legislation on earthquake disaster protection. (3) It appears that both government and citizen rely too much on earthquake prediction to avoid earthquake casualties. (4) Geologic conditions is very complicate and in need of additional studies, especially in southwest of China. There still lack of detail survey on potential geologic disasters, such as landslides.

Although we still cannot predict earthquakes, it is possible to greatly reduce earthquake hazards. For example, some Chinese scientists have begun studies with the aim of identifying active faults under large cities and to propose higher building standards. It will be a very difficult work to improve the quality and scope of earthquake disaster protection dramatically in the coming years due to the factors mentioned above. Nevertheless, a broadly based program of earthquake hazard reduction in urban areas has begun.