The epicentre of the first earthquake was about15km away from Yiliang County, and the epicentre of the second earthquake was about 5km away from the county, which was closer to the densely populated areas, causing greater damage. According to the focal depth, earthquakes can be divided into shallow earthquakes, moderate earthquakes and deep earthquakes. The focal depth is within 60 kilometers, which is called shallow earthquakes. Among them, the focal depth is less than 30 kilometers, which has the greatest impact on human beings. The focal point of this continuous earthquake is only 10 km to 14 km, so it is extremely destructive.
2. The housing quality is poor.
Yiliang County, the epicenter of the earthquake, is located in Wumeng Mountain at the junction of Yunnan, Guizhou and Sichuan provinces. The level of economic development is relatively low, the local people live in poverty, and the seismic performance of houses is generally weak. Some houses are supported by beams, so the bearing capacity is not good, and the building structure itself does not have seismic capacity. After the earthquake, tens of thousands of houses in the county collapsed and were damaged, but the number of collapsed houses in Weining County, Guizhou Province, which is also near the epicenter, is far less than that in yiliang county.
This mountain is high and steep.
Yiliang county has a narrow terrain from east to west, wide from north to south and oblique from north to south. Most areas are cut into eroded mountains by rivers, which has caused objective factors that are prone to secondary disasters. Most of the disaster areas are mountainous terrain, with high mountains and steep slopes and large altitude difference. The highest peak is 2800 meters, the lowest is near 1000 meters, and the drop exceeds 1000 meters. In addition, there are steep mountains and falling rocks. After the earthquake, the mountains on both sides of some roads in Yiliang County near the epicenter collapsed, and rolling stones slipped off the mountains, causing serious traffic jams, which led to the rescue team having to March on foot and slowed down the rescue process.
4. High population density
The average population per square kilometer in Yunnan Province is 1 17, while the population per square kilometer in the earthquake area reaches 205, and the population density in the disaster area is nearly twice that of the whole province. Earthquakes occur in different time periods, which will also lead to huge differences in the number of casualties. For example, at noon when the earthquake occurred, it decided that the occupancy rate of local residents was at a high level, which was a time period prone to casualties.
The emergency response was launched at the first time, and all parties actively participated in disaster relief.
Emergency response was launched immediately after the earthquakes in Yunnan, Zhaotong and Yiliang counties, and departments such as armed police, fire protection, health and electric power actively participated in disaster relief work. The Seismological Bureau of China also launched an emergency response, and sent an on-site emergency team to assist local governments in earthquake relief work. The earthquake site emergency team consists of about 80 people from the earthquake departments at the national, provincial, municipal and county levels, and quickly carries out aftershock monitoring, trend judgment, disaster investigation and loss assessment in the disaster area.
The Yunnan Disaster Reduction Committee has started the first-level emergency response to disaster relief and decided to carry out emergency donation activities to the earthquake-stricken areas in the province. The donation account is: Yunnan Disaster Relief Donation Receiving Office, and the account opening behavior is: Kunming Baiyun Road Sub-branch of Yunnan Agricultural Bank.
The biggest danger to the road leading to Luozehe Town, the hardest hit area of Yiliang earthquake in Yunnan, is the flying stones that may roll down at any time. Of the 80 victims who have been announced, 62 are from this town, and most of the victims were hit by flying stones. On the afternoon of the 8 th, the reporter also experienced this dangerous road on foot.
There are still aftershocks in the area, causing stones of different sizes to roll down from time to time on the mountain. When passing through some particularly dangerous rolling stone sections, be sure to be close to the river and carefully observe the stones on the mountain. Pedestrians must run at a speed of 100 meters when it is certain that there is no big stone rolling down, but they should be prevented from rushing over. Even so, some people were injured by stones.
When we arrived in Luozehe Town, the hardest hit area, most houses in the street had cracked, broken glass could be seen everywhere, and most restaurants and shops had closed. A policeman at the scene told reporters that many victims had been safely transferred to yiliang county.
A public security policeman who participated in the duty introduced that Luozehe Town and the cement plant were the two most severely affected areas. Many houses collapsed and many casualties were injured by rolling stones on the mountain.