## 3 Results  
### Deformation Law Analysis of the Deep Exaxation Channel Slope Based on TerraSAR-X Data  
To comprehensively examine the surface deformation patterns across the entire channel slope area in the study region, we conducted a relevant investigation utilizing SBAS-InSAR technology and 11-view high-resolution TerraSAR-X uplink data. The deformation outcomes, pertaining to the rail lifting baseline and channel slope, are presented in Figures 6 and 7, respectively. Figure 6: TerraSAR-X data track baseline. According to processing results of the TerraSAR-X data (Figure 7), the surface deformation characteristics of the deep-dug expansive-soil channel section in the middle route of the South-North Water-Diversion Project could be classified into two main types: uplift and settlement. The uplift deformation area was mainly located in the middle and downstream of the channel in the study area and the settlement deformation area in the middle and upstream of the channel in this section. Notably, the uplift deformation area was not only larger in scope than the settlement area but also more serious in the degree of deformation. Furthermore, the uplift deformation was more severe on the right bank of the channel than on the left bank. The spatial distribution of the deformation could be classified into four distinct regions (as shown in Figure 7). There was almost no deformation of the channel slopes within the range of region A, with an annual deformation rate of \(-5\) mm/y to \(+5\) mm/y. In area B, the channel slopes were mainly subsided, with an annual settlement rate ranging from \(-15\) mm/y to \(+5\) mm/y. In the range of area C, the channel slope deformation was dominated by an uplift. The maximum uplift deformation of the channel slope accumulated more than \(19\) mm per year; in fact, in the range of the region, the uplift deformation caused serious damage to the channel slope (Figure 8). Consequently, based on these findings, channel management personnel have undertaken necessary reinforcement measures in the severely deformed areas. Additionally, a GNSS monitoring station has been installed at a representative deformation point to enable the real-time monitoring of surface deformation, facilitating a scientific assessment of the channel slope's safety. In region D, the channel slope deformation was also predominantly uplifted, with a maximum uplift deformation of approximately \(12\) mm per year. However, compared to region C, the lifting deformation in this area was relatively minor. Through on-site investigations, no evidence of damage to the channel slope was observed. To further reveal the temporal deformation characteristics of the channel slope, we randomly selected two points, P1 and P2, in the severe uplift deformation region C and a point, P3, in the settlement region B. Taking these three points as examples, relevant temporal deformation values were extracted to carry out research, as shown in Figure 9. The timeseries deformation values of the three monitoring points revealed a certain periodicity  
Figure 7: Treatment results of the channel slope deformation based on the TerraSAR-X data: (**A**) no deformation zone; (**B**) slight subsidence zone; (**C**) severely uplifted deformation zone; (**D**) slightly uplifted deformation zone. in both the uplift deformation and settlement deformation processes. All three points experienced a deformation pattern of \"lifting\(\rightarrow\)settling\(\rightarrow\)lifting\" during the time period, as shown in Table 2. Since P1 and P2 are both in zone C, where severe uplift and deformation occurred, their deformation rules were basically the same. From 10 June 2020, both points have sustained uplift and deformation, and they reached the maximum value on 29 August 2020. Subsequently, the uplift and deformation fell back somewhat and stopped falling on 28 October 2020 and then occurred again. From this trend, the re-uplifting deformation value may exceed the previous peak value.