## 2 Materials and Methods
### Data Source  
PLES dataset in this study was from 1:100,000 scale land use database of China Academy of Sciences ([[http://www.resdc.cn/](http://www.resdc.cn/)]([http://www.resdc.cn/](http://www.resdc.cn/)), accessed on 1 September 2021) [30; 31; 32; 33]. The dataset was conducted by Resources and Environment Research Center, Institute of Geography, Chinese Academy of Sciences. It was based on Landsat long-time series remote-sensing images as the main data source and generated through human-computer interaction visual remote-sensing interpretation. Land use types include 6 primary types (cultivated land, forest land, grassland, water area, residential land and unused land) and 25 secondary types. Through verification and analysis of a large number of samples, the comprehensive assessment accuracy of first level in China reached over 94.3%, which met the mapping accuracy requirements of 1:100,000 scale users [34]. This data has been widely  
Figure 1: Research area of Beijing-Tianjin-Hebei region.  
used in the study of land use, which has advantages in time span and data consistency and can be used for land-use changes in long time series.  
Besides this, endowment factors include three types: natural characteristics, location characteristics and facility characteristics. Natural features included elevation, topographic relief and the distance to water. Elevation and relief intensity index were measured by Digital Elevation Model (DEM, GDEM_V2_30 m), which was obtained from geospatial data cloud ([[http://www.gscloud.cn/](http://www.gscloud.cn/)]([http://www.gscloud.cn/](http://www.gscloud.cn/)), accessed on 3 September 2021). Water surface includes level 1, 3, 4 and 5 rivers and lakes, which was obtained from National Catalogue Service for Geographic Information ([[https://www.webmap.cn/](https://www.webmap.cn/)]([https://www.webmap.cn/](https://www.webmap.cn/)), accessed on 1 September 2021), 1:250,000 National basic Geographic database. Location characteristics include three indexes: distance to the nearest subdistrict, city and capital. Original data was the border shapefile of towns and subdistricts, which was obtained from the Data Center for Resources and Environmental Sciences, China Academy of Sciences ([[https://www.resdc.cn/](https://www.resdc.cn/)]([https://www.resdc.cn/](https://www.resdc.cn/)), accessed on 1 September 2021). Rural areas and urban areas can be clearly distinguished by unit types. Three location indexes represented the urban attractiveness from low to high. Facility characteristics were described by the distance to interchanges and roads. The distribution of interchanges and roads were acquired from TiandiMap ([[https://www.tianditu.gov.cn/](https://www.tianditu.gov.cn/)]([https://www.tianditu.gov.cn/](https://www.tianditu.gov.cn/)), accessed on 5 September 2021) and AMap open platform ([[https://lbs.amap.com/](https://lbs.amap.com/)]([https://lbs.amap.com/](https://lbs.amap.com/)), accessed on 5 September 2021). All distance indices were manipulated through the path distance tool in ArcGIS 10.3 ([[https://www.esri.com/en-us/arcgis/products/arcgis-desktop](https://www.esri.com/en-us/arcgis/products/arcgis-desktop)]([https://www.esri.com/en-us/arcgis/products/arcgis-desktop](https://www.esri.com/en-us/arcgis/products/arcgis-desktop)), accessed on 30 June 2021).