Spatial correlation between land subsidence and urbanization in Beijing, China

The large-scale construction of buildings, extensive road and rail networks, and increased traffic flow associated with urbanization has the potential to cause land subsidence. Land subsidence caused by urbanization is an increasingly significant problem in Beijing, China; therefore, it is important to investigate the relationship between urbanization and land subsidence. Landsat TM images covering the Beijing plain were used to acquire spatial changes information of built-up areas by calculating an index-based built-up index (IBI). We used ENVISAT Advanced Synthetic Aperture Radar data acquired from 2003 to 2009 and persistent scatterers for SAR interferometry (PSI) technology to estimate land subsidence. Geographic information systems spatial analysis method was used to identify the relationship between the settlement rate and the IBI value for three different sampling units. The result showed that it was a positive correlation between construction density and land subsidence; for land subsidence, the effect from the combination of high-density building clusters and extensive transportation networks was more significant than the presence of buildings alone. However, there may be a delay between the completion of building construction and the development of land subsidence.