Satellite Deformation Imaging of Mountain Excavation for Urbanization in China

The demand for land exploitation to accommodate increasing population in metropolis is escalating worldwide. The unprecedented Mountain Excavation and City Construction project in the hilly-gully Loess Plateau of China is a crustal surgery to seek the balance between urbanization and sustainability in the forerunner Yanan city. A total of 33 hilltops have been cut and dozens of gullies have been filled to create the flat terrain. Here we rely on multi-source remote sensing data, e.g., Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) obtained in 2000, TanDEM-X DEM obtained in 2015, optical Landsat and Copernicus Sentinel-2 images, and two overlapping ascending tracks of Copernicus Sentinel-1 Synthetic Aperture Radar (SAR) satellite imagery, to characterize the contemporary anthropogenic modification of the loess landscape. The topography has been reshaped with 80-m elevation changes and 1.28108-m3 mass transfer by 2015. The subsidence rates at up to ~70 mm/yr during 2014-2020 are proportional to the amount of the filling mass, which is expected to reach stabilization by 2030 according to our statistical analysis. Our numerical model gives out stress perturbation by hundreds of kPa in the shallow crust. This study demonstrates the capabilities of remote sensing in characterizing the human-nature interactions from the space.