## 2 Methods
### Pre-Earthquake Phase
#### 2.1.1 Population Distribution
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Age** & **8:00–17:30** & **17:30–22:00** & **22:00–8:00** \\ \hline \multirow{4}{*}{0–14} & \multirow{4}{*}{Educational services} & Accommodation service & \\  & & Commercial service & accommodation service \\  & & Leisure service & \\  & & Accommodation service & \\  & & Hospital service & Accommodation service \\  & & Hospital service & Accommodation service \\  & & Liveilhood service & Leisure service \\
14–60 & & Liveilhood service & Commercial service & Enterprise office \\  & & Enterprise office & Leisure service \\  & & Leisure service & Leisure service \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Different ages on weekdays in the functional area. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Age** & **8:00–17:30** & **17:30–22:00** & **22:00–8:00** \\ \hline \multirow{4}{*}{0–14} & \multirow{4}{*}{Educational services} & Accommodation service & \\  & & Leisure service & \\  & & Accommodation service & \\  & & Hospital service & Accommodation service \\  & & Hospital service & Accommodation service \\  & & Hospital service & Accommodation service \\  & & Hospital service & Accommodation service \\
14–60 & & Tourist attraction & Commercial service & Commercial service \\  & & Leisure service & Leisure service \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Different ages in the rest weekdays in the functional area. 5.1 m. Therefore, the height of ordinary residential floors in this paper is set to 2.7 m, and the floor height of stores is set to 4.8 m. Finally, the area of the top surface of the building multiplied by the height of the floor is obtained. 2. Identification of the building function \(i\)  
As buildings are an important part of cities, the functional classification of urban buildings can provide a favorable basis for the division of urban functional areas, assist government departments in managing and making decisions on the distribution and allocation of urban planning [30; 31; 32], land use [33], resources [34], and population [35], and help promote the sustainable development of urbanization construction [36]. In our study, the results of the determination of building function can effectively improve the accuracy of the indoor population rate, and can be effectively applied to the risk assessment of the seismic people trapped. In this paper, a method of functional classification of buildings based on high-resolution remote sensing imagery is proposed and used. Firstly, the building edge information in the pre-earthquake high-resolution remote sensing images is extracted using deep learning method. Then, the POI data are sorted and classified according to the experimental idea, and finally, the two are fused together to realize the functional judgment and classification of single buildings before a disaster. There are too many types of POI data, and a single functional building often contains multiple POI points. Consider the similarity of multiple functions, it is necessary to delete and merge POI data. In this paper, according to the Classification Standard of Land Use Status (GB/T21010-2017), building functions are divided into 8 categories, including accommodation service, hospital service, livelihood service, enterprise office, commercial service, tourist attraction, educational service, and leisure service. The data classification results are shown in Figure 2.  
Figure 2: POI functional classification.