# The Spatial Optimization of Emergency Shelters Based on an Urban-Scale Evacuation Simulation
## 5 Results
### Spatial Optimization of Emergency Shelters  
Table 5 presents detailed information regarding the spatial optimization of short-term fixed shelters, including the number of remaining non-evacuated people that were allocated to each route and the time spent evacuating, as well as the effective shelter area that should be provided by each target plot. The statistics show that the average time that was spent on allocating the non-evacuated people for all routes was approximately 15.9 min, and the average number of non-evacuated people that were allocated to a route was approximately 1047. When the 757 target plots had received all the remaining non-evacuated people from the nearby incompletely evacuated demand points, the average time that had passed was approximately 23.4 min. This long duration was caused by the large number of people remaining at some points. The average number of people that were allocated to the target plots was approximately 4537, and most of the plots should provide an effective shelter area of more than 5000 m\({}^{2}\). The calculation of the model for the spatial optimization of the temporary shelters reveals that the average time that was spent on all the routes \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Evacuation Scene** & **Statistics** & **Haizhu** & **Liwan** & **Tianhe** & **Yuexiu** \\ \hline \multirow{3}{*}{Emergency sheltering} & N1 & 953,138 & 321,330 & 897,862 & 947,163 \\  & N2 & 818 & 956 & 2206 & 2223 \\ \cline{1-1}  & N3 & 26,372 & 17,045 & 31,848 & 31,661 \\ \cline{1-1}  & N1 & 1,112,254 & 359,612 & 586,861 & 930,511 \\ \cline{1-1}  & N2 & 955 & 1070 & 1442 & 2184 \\ \cline{1-1}  & N3 & 31,320 & 17,321 & 28,023 & 31,757 \\ \hline \hline \end{tabular} Notes: N1 is the total number of non-evacuated people; N2 is the average number of non-evacuated people at the demand points; N3 is the maximum number of non-evacuated people among the demand points.  
\end{table} 
Table 4: Non-evacuated people at the demand points of different evacuation scenes. Figure 6: The distribution of non-evacuated people in the context of short-term fixed sheltering. was approximately 13.5 min, and the average number of non-evacuated people that were allocated to the routes was approximately 1307. When the 772 target plots had received all the remaining non-evacuated people from the nearby incomplete evacuation demand points, the average time that had passed was approximately 22.2 min. The average number of people that were allocated to the target plots was approximately 4130, and most of the plots should provide an effective shelter area of more than 4000 m\({}^{2}\). When comparing the effective area of the short-term fixed shelters with the effective area of the temporary shelters that the plot should provide, the maximum of the two is the effective shelter area that the plot should ultimately provide. The distribution and scale of the spatial optimization of the emergency shelters on the target plots are shown in Figure 7, from which it is evident that each district should considerably increase the scale of shelters. The numbers of target plots that should be added for newly available shelter resources in Haizhu, Yuexiu, Liwa, and Tianhe are, respectively, 406, 164, 141, and 136, with effective shelter areas of 2,621,100, 2,175,300, 812,100, and 1,344,600 m\({}^{2}\), respectively. Moreover, the average newly added effective shelter areas of the plots for Haizhu, Yuexiu, Liwa, and Tianhe were found to be 6456, 13,264, 5759, and 9886 m\({}^{2}\), respectively. Based on the newly added effective shelter area of the target plot, and combined with the supply and demand status of the short-term fixed shelters and temporary shelters after the evacuation simulation, the spatial optimization target for the shelters on each plot was divided into two types, namely fixed and temporary shelters (Table 6). A total of 487 short-term fixed shelters and 360 temporary shelters were newly added.