## 2 Materials and Methods
### Urban Green Space Information Evaluation Index System  
#### 2.4.1 Analysis and Calculation Methods of Urban Green Zone Information  
The study area encompasses a significant number of parks, and the spatial distribution patterns of these parks vary between the inner (2 nd Ring Road) and the outer rings. In this study, park green space information was analyzed from three aspects, namely, basic quantity characteristics, green space landscape pattern, and service capacity. 1. The analysis of the characteristics of the basic quantity of urban green zones included the green coverage rate, the irrigation coverage rate, and the ratio of blue to green space, which characterizes the situation of the basic quantity of urban green zones. The corresponding equations are as follows: \[\text{Green coverage}(\%)=\frac{\text{Vertical projection area of all vegetation within the park}\Big{(}\text{hm}^{2}\Big{)}}{\text{Park area}\Big{(}\text{hm}^{2}\Big{)}}\] \[\text{Percentage of irrigation cover}(\%)=\frac{\text{Vertical projection of irrigation in the park}\Big{(}\text{hm}^{2}\Big{)}}{\text{Vertical projection area of all vegetation within the park}\Big{(}\text{hm}^{2}\Big{)}}\] \[\text{Percentage of blue - green space}(\%)=\frac{\text{Total area of green space and water within the park}\Big{(}\text{hm}^{2}\Big{)}}{\text{Park area}\Big{(}\text{hm}^{2}\Big{)}}\] 2. The Fragstats software was employed to compute three indices pertaining to landscape fragmentation, landscape aggregation, and landscape diversity, (see Table 2 for further details). The Fragstats 4.2.1 software is a spatial pattern analysis program used to quantify landscape structure and mainly applied to calculate multiple landscape pattern indices of classified map patterns [25; 46; 47]. Data analysis and processing are implemented through a graphical user interface or a command line. Collectively, these indicators illustrate the configuration and distribution of urban green landscape patches. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Evaluation Indicators** & **Equation** & **Reference** \\ \hline UA & \(\text{UA}=\frac{\text{TP}}{\text{TP}+\text{FP}}\) \\ PA & \(\text{PA}=\frac{\text{TP}+\text{TN}}{\text{TP}+\text{TN}}\) \\ OA & \(\text{OA}=\frac{\sum\limits_{i=1}^{\text{N}}\text{X}_{ii}}{\text{N}}\) \\ Kappa & \(\text{K}=\frac{\text{N}\sum\limits_{i=1}^{\text{N}}\text{X}_{ii}-\text{N}_{ii} \cdot\text{X}_{ii}}{\text{N}^{2}-\sum\limits_{i=1}^{\text{N}}\left(\text{X}_{ ii}\cdot\text{X}_{ii}\right)}{\text{N}^{2}-\sum\limits_{i=1}^{\text{N}}\left(\text{X}_{ ii}\cdot\text{X}_{ii}\right)}\) \\ \hline \hline \end{tabular} Note: N is the composite of the number of categories (total number of pixels); n is the category. \(\text{X}_{ii}\) denotes the diagonal element of the confusion matrix, i.e., the number of pixels for category i; \(\text{X}_{ii}\) represents the aggregate of the column values within the category; and \(\text{X}_{ii}\) denotes the total of the row values within the same category.  
\end{table} 
Table 1: Index calculation equations. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Landscape Index Name** & **Unit** & **Index Meaning** & **Equation** & **Reference** \\ \hline \multirow{4}{*}{Landscape fragmentation} & \multirow{4}{*}{Plaque density, PD fragmentation mean} & With increasing value, the fragmentation of landscape patches increases, & PD = \(\frac{\text{NP}}{\text{N}}\) & [25] \\  & & & Characterizes the degree of landscape fragmentation. & AREA\_MN = \(\frac{\text{SD}}{\text{N}}\) & \\  & Connectivity index, COHESION & \% & Characterizes the degree of patches in the landscape. & COHESION = \\  & & & Characterizes the degree of & \(\left[1-\frac{\text{TP}_{1}\text{TP}_{1}\text{TP}_{1}\text{TP}_
3. In this study, the service capacity of urban green zones within the Fifth Ring Road area of Beijing was examined, focusing on the coverage rate of the service radius of these green spaces and their accessibility [1; 48; 49; 50].