## 2 Materials and Methods
### Method
#### 2.3.3 Ecological Resilience Measurement Model
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Land-Use Types** &
\begin{tabular}{c} **Habitat** \\ **Level** \\ \end{tabular} & **Corp** & **Urban** & **Rural** & **Others** & **Unused** \\ \hline Corp & 0.5 & 0 & 0.8 & 0.6 & 0.7 & 0.3 \\ Woodland & 1 & 0.8 & 0.9 & 0.8 & 0.8 & 0.5 \\ Shrub land & 0.9 & 0.7 & 0.8 & 0.7 & 0.7 & 0.4 \\ Sparse woodlands & 0.8 & 0.6 & 0.7 & 0.7 & 0.6 & 0.5 \\ Other woodland & 0.8 & 0.6 & 0.7 & 0.6 & 0.6 & 0.5 \\ High-cover grassland & 0.9 & 0.6 & 0.7 & 0.7 & 0.7 & 0.6 \\ Medium-cover & & & & & & \\ grassland & 0.8 & 0.6 & 0.6 & 0.5 & 0.6 & 0.5 \\ Low-cover grassland & 0.7 & 0.5 & 0.5 & 0.5 & 0.6 & 0.5 \\ Rivers and lakes & 1 & 0.6 & 0.9 & 0.7 & 0.5 & 0.4 \\ Reservoirs and & & & & & & \\ beaches & & & & & & \\ Glaciers and & & & & & & \\ permanent snowfields & & & & & & \\ Urban & 0 & 0 & 0 & 0 & 0 & 0 \\ Rural & 0 & 0 & 0 & 0 & 0 & 0 \\ Others & 0 & 0 & 0 & 0 & 0 & 0 \\ Sand, gobi, and bare & & & & & & \\ ground & & & & & & \\ Saline soil & 0.1 & 0.2 & 0.2 & 0.1 & 0 & 0 \\ Marshall & 0.4 & 0.6 & 0.6 & 0.5 & 0.4 & 0.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Sensitivity of different types of land to threat sources. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Threats** & **Maximum Impact Distance/km** & **Weights** & **Decay** \\ \hline Corp & 6 & 0.6 & linear \\ Urban & 10 & 0.9 & exponential \\ Rural & 8 & 0.7 & exponential \\ Others & 6 & 0.6 & exponential \\ Unused & 4 & 0.4 & exponential \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Weight of threat sources and maximum distance of impact. (2) Landscape pattern index representation--landscape heterogeneity and landscape connectivity. The landscape pattern index can quantitatively express the correlation between landscape patterns and ecological processes and evaluate the structural stability of ecological resilience with respect to landscape heterogeneity (D) and landscape connectivity (C) [47]. Grassland and woodland have the most important ecological functions in arid-zone landscapes, and this study draws on existing research results to incorporate grassland connectivity into the evaluation of the structural stability level of ecological resilience in the UANST. Landscape heterogeneity is composed of two components, the area-weighted mean patch fractal dimension (\(AWMPFD\)) and Shannon's Diversity Index (\(SHDI\)), which are characterized in terms of the complexity of patch shapes and the differences in land-use types in the grid, respectively. The \(AWMPFD\) and the \(SHDI\) are positively proportional to landscape heterogeneity. Based on previous studies, the weights assigned to \(AWMPFD\) and \(SHDI\) in this study were 0.15 and 0.25, respectively [18]. Landscape connectivity is determined by the whole landscape, woodland connectivity, and grassland connectivity, quantified by the indexes of patch fragmentation and patch spreading. The patch fragmentation index (\(LN\)) was negatively correlated with landscape connectivity, and the patch spread index (\(L_{CONTAG}\)) was positively correlated with landscape connectivity. Therefore, connectivity across the landscape was measured using these two indexes. The fragmentation indices (\(FN\) and \(GN\)) and patch aggregation (\(F_{COHESION}\) and \(G_{COHESION}\)) of the woodland and grassland were utilized to characterize the connectivity between the two ecosystems, and the weights were set to 0.1 [18]. The formula for the landscape pattern index (A) is as follows:  
\[ \begin{array}{ll}\text{A}=&0.4\text{D}+0.6\text{C}\\ &=(0.25 SHDI+0.15 AWMPFD)+(0.1 LN+0.1L_{CONTAG}+0.1 FN+0.1F_{COHESION}+0.1 GN\\ &+0.1G_{COHESION})\end{array}