## 4 Results and Verification
### InSAR Experimental Results and Field Cross-Validation  
To verify the InSAR results, we conducted a field investigation of the deformed region. Figure 8 shows in situ photographs and the cumulative time-series deformation at corresponding positions. Points b and c in Figure 8 are located in Yejia village, which is sandwiched between two rivers leading to Dianchi Lake. Obvious tensile cracks have occurred in part of the ground and building walls, as shown in Figure 8,c. Point d in Figure 8 is located in a newly built community along Dianchi Lake. While the foundation of the building itself has remained stable, the area has exhibited settlement. Obvious tensile cracks have occurred at the bottom of the building edge in Figure 8. The cumulative displacements in the vertical direction of points b, c and d from February 2018 to May 2021 are shown in Figure 8. The displacement at these three points shows a linear deformation trend.  
In addition, we selected six characteristic points A\({}_{1}\)-A\({}_{6}\) in regions S\({}_{1}\) and S\({}_{2}\), and analyzed the time-series cumulative displacements in the deformed regions. All these  
Figure 8: (**a**) Locations of the field investigation superimposed on the vertical annual mean deformation rate calculated from the ascending dataset. (**b**) Cracks on the ground at position b in Figure 8. (**c**) Cracks on the wall at position c in Figure 8. (**d**) Cracks at the bottom of the building at position c in Figure 8. (**e**) Cumulative displacements of vertical deformation in position b, c and d.  
Figure 7: Annual mean deformation rate diagram in the vertical direction along section line P-P\({}^{\prime}\).  
points are marked with black triangles in Figure 9. Points A\({}_{1}\) to A\({}_{3}\) are located around the Dianchi International Exhibition Center. Among them, A\({}_{1}\) and A\({}_{2}\) are two newly built communities located on the peninsula. The construction of large-scale communities on lakeside sediments has greatly increased ground loads and caused surface subsidence. A\({}_{3}\) is an urban village named Yejia Village, which is sandwiched between two rivers leading to Dianchi Lake. Its subsidence is caused by geological factors and the quality issues related to the self-built houses. Compared with the controllable deformation of new communities A\({}_{1}\) and A\({}_{2}\), the deformation signal of Yejia Village is more dangerous.  
A\({}_{3}\)-A\({}_{6}\) in region S\({}_{2}\) surrounds the large community, Vanke Community. The area is located in the vicinity of Xiaobanqiao, which has historically been subject to severe subsidence. Figure 10 shows the time-series cumulative vertical displacements at points A\({}_{1}\)-A\({}_{6}\) from 2018 to 2021. The vertical annual mean deformation rate is approximately \(-13\) mm/a for the points of A\({}_{1}\)-A\({}_{3}\). The maximum cumulative deformation reached \(-45.36\) mm over three years. The vertical annual mean deformation rate for A\({}_{4}\)-A\({}_{6}\) near the Vanke Community is approximately \(-12.2\) mm/a, with a maximum cumulative displacement of \(-42.72\) mm.  
Figure 9: Zoomed-in view of the deformation rate results in S\({}_{1}\) and S\({}_{2}\). The locations of A\({}_{1}\)–A\({}_{6}\) are marked with black triangles.  
From the time-series results, we find that, overall, the displacements on these points show a linear trend. The displacement on point A\({}_{1}\) exhibits some jitter, probably due to the atmospheric disturbances that are not completely removed. The displacements of points A\({}_{4}\) and A\({}_{5}\) show a gradual slowing trend. Points A\({}_{4}\) and A\({}_{5}\) deformed by approximately 20 mm from February 2018 to May 2019; however, after May 2019, these points took more than 20 months to settle by 20 mm. This is consistent with the deformation characteristics of soft ground consolidation under load after the construction of a large number of high-rise buildings.