# A Method for Evaluating the Spatial Layout of Fire Stations in Chemical Industrial Parks
## 2 Methods  
### General Framework  
In this article, the proposed evaluation method for the spatial layout of fire stations in chemical industrial parks is carried out in the following steps:  
(1) Classify the fire risk of the PTBR and determine the corresponding required fire rescue time for each fire risk level. \(\blacksquare\) Establish a set of PTBRs as \(R=\{R_{1}\), \(R_{2}\), \(\ldots\), \(R_{n}\}\), where \(R_{1}\)-\(R_{n}\) represent each PTBR, and n is the total number of PTBRs in the park. \(\blacksquare\) Establish a set of fire risk levels as \(W=\{W_{1}\), \(W_{2}\), \(\ldots\), \(W_{m}\}\), where \(W_{1}\)-\(W_{m}\) are the fire risk levels of PTBRs, and m represents the total number of risk levels. \(\blacksquare\) Establish a set of required fire rescue time standards as \(T=\{T_{1}\), \(T_{2}\), \(\ldots\), \(T_{m}\}\), where \(T_{1}\), \(T_{2}\), \(\ldots\)\(T_{m}\) are the required fire rescue time standards for the fire risk levels \(W_{1}\), \(W_{2}\), \(\ldots\)\(W_{m}\). Traverse the set \(R\) to establish a set of required fire rescue times as \(X=\{X_{1}\), \(X_{2}\), \(\ldots\), \(X_{n}\}\), where \(X_{1}\)-\(X_{n}\) are the required fire rescue times for the corresponding PTBRs. The required fire rescue time for each PTBR should be determined based on its fire risk level. The fire risk assessment technology will be described in the following section. (2) Analyze and build a rescue road network within the chemical industrial park, and estimate the running speed of fire engines in the park. These parameters are used to calculate the estimated fire rescue times from each PTBR to each fire station. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Identification**} & \multirow{2}{*}{**General Location**} & \multirow{2}{*}{**Area, km\({}^{2}\)**} & \multirow{2}{*}{**FS Number**} & \multirow{2}{*}{**FS Coverage Rate**} & \multicolumn{2}{c}{**FS**} \\  & & & & & **Overlap-Coverage** \\  & & & & & **Rate** \\ \hline Park A & North China & 15 & 3 & 94\% & 76\% \\ Park B & Northeast China & 13.02 & 2 & 97\% & 24\% \\ Park C & Southeast China & 6.60 & 4 & 96\% & 82\% \\ Park D & Southwest China & 4.50 & 1 & 98\% & - \\ Park E & Southwest China & 18.57 & 3 & 62\% & 0\% \\ Park F & Southwest China & 4.74 & 1 & 100\% & - \\ Park X & Southwest China & 11.33 & 2 & 92.6\% & 62\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Information on the chemical industrial parks where this method has been implemented. FS stands for fire station. Establish a set of fire stations as \(F=\{F_{1},F_{2},\ldots,F_{\rm{k}}\}\), where \(F_{1}\)-\(F_{\rm{k}}\) represent the fire stations in the chemical industrial park, and k is the total number of fire stations. * Establish the minimum distance path from each PTBR to each fire station as \[P_{ij}=\left[ \begin{array}{cccc}P_{11}&P_{12}&\cdots&P_{1\rm{k}}\\ P_{21}&P_{22}&\cdots&P_{2\rm{k}}\\ &\cdots&\\ P_{\rm{n}1}&P_{\rm{n}2}&\cdots&P_{\rm{nk}}\end{array} \right]\] (1) where \(P_{ij}\) represents the minimum distance path from \(R_{i}\) to \(F_{j}\), and where \(i\) ranges from 1 to n and \(j\) ranges from 1 to k.
* Estimate the fire rescue time from each PTBR to each fire station as \[t_{ij}=P_{ij}/V=\left[ \begin{array}{cccc}t_{11}&t_{12}&\cdots&t_{1\rm{k}}\\ t_{21}&t_{22}&\cdots&t_{2\rm{k}}\\ &\cdots&\\ t_{\rm{n}1}&t_{\rm{n}2}&\cdots&t_{\rm{nk}}\end{array} \right]\] (2) where \(V\) represents the estimated running speed of fire engines in the chemical industrial park, and \(t_{ij}\) represents the estimated fire rescue time from \(R_{i}\) to \(F_{j}\). * Compare the estimated fire rescue time with the required fire rescue time, and calculate the coverage rate and overlap-coverage rate of the fire stations.