## 3 Results
### Basic Descriptive Endowment Characteristics of PLES Types  
The PLES pattern of the study area changed a little in the past decades. The current PLES distribution and endowment characteristics were combined for further analysis. Table 2 shows the mean value and standard deviation of the indicators of each type.  
There is a great difference among PLES types. From the natural factor index, LS occupies the position with a lower elevation and less fluctuation, while ES is relatively distributed in the region with a higher elevation and steep terrain, and PS is between them. Compared with the STD of elevation and relief intensity of the other types, the values of LS are all small, indicating that LS has more stringent requirements on terrain and a smaller  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{6}{c}{**Natural Factors**} & \multicolumn{3}{c}{**Location Factors**} & \multicolumn{3}{c}{**Facility Factors**} \\ \hline  & **EL (m)** & **RI (m)** & **DW (m)** & **DS (m)** & **DCI (m)** & **DCA (m)** & **DI (m)** & **DR (m)** \\  & **MEAN** & **MEAN** & **MEAN** & **MEAN** & **MEAN** & **MEAN** & **MEAN** & **MEAN** \\ PS & 327 & 22 & 1021 & 20,713 & 45,431 & 109,863 & 11,181 & 386 \\ LS & 130 & 13 & 974 & 14,842 & 32,827 & 85,977 & 8095 & 207 \\ ES & 834 & 99 & 1113 & 34,862 & 66,259 & 132,104 & 18,505 & 698 \\ \hline  & **STD** & **STD** & **STD** & **STD** & **STD** & **STD** & **STD** \\ PS & 493 & 26 & 1291 & 18,690 & 30,532 & 62,463 & 9825 & 340 \\ LS & 278 & 14 & 1108 & 15,246 & 24,603 & 59,160 & 6728 & 218 \\ ES & 483 & 56 & 997 & 22,520 & 35,934 & 64,910 & 14,052 & 577 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Mean value and STD of factors of PLES (EL—elevation; RI— relief intensity; DW—distance to water; DS—distance to subdistricts; DCI—distance to cities; DCA—distance to capitals; DI—distance to interchanges; DR—distance to roads).  
Figure 4: Area of PLES from 1980 to 2018.  
suitable range than PS and ES. The distance from water has little difference among them. After their differences were magnified, we found that the average distance to water in ES is the biggest and the STD is the smallest. Considering that ecological space includes rivers and lakes, it further shows that PS and LS had a strong demand for water. The location factor results show consistency in all indicators, and indexes of LS are smaller than PS and ES. It can be considered that the LS in rural areas was inherited from the urban spatial hierarchy. Additionally, the gap among PLES types shown in the distance to the capital is bigger than in the distance to subdistricts. A higher level of urban area has more attraction to rural LS. PS and ES are distributed around the LS patches, which made ES have a maximum distance to the urban area at every level. The facility factor indexes results show that the expressway is an important factor to change spatiotemporal distance, as it connects large cities, towns and the wide rural space. Interchanges are also the spatial trigger of rural development. The distance to roads is similar. It is noteworthy that LS is closer to the area with convenient facilities, and the preference level of LS and ES for facility indicators is very different. We guessed that by considering the elevation and relief intensity index results of ES, there is a bigger cost for building interchanges and roads in ecological areas. It also contributed to the distance from ES to the infrastructure elements.