Abstract:
On December 18, 2023, a
MS6.2 earthquake occurred in Jishishan County, Linxia Hui Autonomous Prefecture, Gansu Province, causing significant casualties, buildings collapsed and geological disasters. Based on the spatiotemporal distribution characteristics of historical earthquakes in Gansu Province, this paper analyzes the disaster characteristics of the Jishishan earthquake by comparing with other similar magnitude earthquake disasters in the region. Combined with field investigation data, the influencing factors of the earthquake disaster are analyzed from multiple perspectives. The results show that the Jishishan earthquake disaster area belongs to the earthquake disaster-prone area, and is currently in a relatively active period of regional earthquakes. Compared with the historical earthquake disasters of similar magnitude, the disaster loss caused by the earthquake is greater. The thrust seismogenic structure, shallow epicenter and the site amplification effect of loess deposition are the main factors that increase the destructive force of the earthquake. The civil or brick-wood housing structure with low seismic performance is the main cause of severe damage and collapse of buildings in the disaster area. The earthquake occurred in the early morning of the night, when the people were basically in a sleep state, which greatly shortened the people's emergency evacuation and response time, aggravating casualties. The low temperature, plateau cold, steep slope and other harsh environmental conditions not only reduce the survival probability of the buried people, but also greatly compress the golden rescue time and increase the difficulty of rescue. The high proportion of vulnerable groups such as the elderly and children, and their weak disaster awareness and disaster response ability further aggravate the regional casualties. Finally, the paper puts forward some suggestions on earthquake disaster prevention, reduction and relief in the region.