2.3 Data sources
The data of land use type in 2017 was 10-m resolution and got fromhttp://data.ess.tsinghua.edu.cn/, which was 72.76% in overall accuracy (Gong et al., 2019). The land use types were classified into cropland, forest, grassland, shrubland, wetland, water body, tundra, impervious area, bare land, and snow/ice (Gong et al., 2019).
The position data about road, place and waterway were got form Openstreetmap (https://www.openstreetmap.org/). In this website, the roads were classified into trunk road, primary road, secondary road, tertiary road, residential road, cycleway, footway and so on (http://wiki.openstreetmap.org/wiki/Key:highway). The places were classified into country, province, county, town, village and so on (https://wiki.openstreetmap.org/wiki/Key:place). The waterway were classified into river, stream, drain, ditch and so on (https://wiki.openstreetmap.org/wiki/Key:waterway).