1. School of Architecture and Urban Planning, Beijing University of Civil Engineering and Architecture, Zhanlanguan Road 1, Xicheng District, Beijing 100044, China
2. School of Geomatics and Urban Spatial Information, Beijing University of Civil Engineering and Architecture, Beijing 102616, China
3. Key Laboratory of Urban Spatial Information, Ministry of Natural Resources, Beijing University of Civil Engineering and Architecture, Beijing 102616, China
4. School of Landscape Architecture, Beijing Forestry University, Beijing 100083, China