## 3 Results
### Suspected Active Controlled Landslides  
Table 3 shows the suspected active landslides with engineering remedial work, their highest InSAR displacement rate at the slope direction, the deformation scale, and implemented type of engineering remedial works. The next step of the proposed methodology aimed at identifying potentially instable slopes or the failure of engineering remedial work and confirmed the activity level of this suspected \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Number** & **Percentage** & **Area (km\({}^{2}\))** & **Percentage of Area** \\ \hline Controlled landslides confirmed active & 2 & 0.65 & 0.09 & 0.28 \\ Controlled landslides suspected to be active & 9 & 2.90 & 1.83 & 5.69 \\ Controlled landslides that are inactive & 47 & 15.16 & 8.76 & 27.24 \\ Uncontrolled landslides that are active & 41 & 13.23 & 3.71 & 11.53 \\ Uncontrolled landslide that are inactive & 211 & 68.06 & 17.77 & 55.26 \\ All landslides & 310 & 100 & 32.16 & 100 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Result of the deformation inspection based on the proposed procedure. cases. Through our field investigations, nine of them (No.1 and No.4-No.11) were considered as very slow deforming, and no signs of persistent deformation were detected on the landslide body or buildings on it. In addition, their engineering remedial structures were all intact and well-functioning, despite that some of them were deeply planted into the ground and hard to check. Figure 6 shows the displacement rate map and deformation features of the Ertunping landslide, such as building cracks at the middle part of the sliding body, and bank collapse at the front edge. The landslide showed no obvious signs of continuous overall deformation, and deformation features, such as pre-existing building cracks, also showed no developing tendency. The implemented engineering structures, including anchors on the trailing, anti-slide piles, and retaining wall on the front edge, all maintained fixed positions and functioned well. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**No.** & **Landslide Name** & **Max Vslope** **(mm/yr)** & **Sliding** & **Situation of Monitoring** & **Engineering Remedial** **Work** \\ \hline
1 & Ertunping landslide & 17.29 & Local & InSAR & 1,2,3 \\ \hline
2 & Dazhou landslide & 15.80 & Local & Ground/InSAR & 1,2 \\ \hline
3 & Kangliapuo landslide & 17.88 & Local & InSAR & 1,2 \\ \hline
4 & Dadiping landslide & 28.71 & Local & InSAR & 1,2 \\ \hline
5 & Xiaoshipan rockfall & 35.00 & Local & InSAR & 1,2,3 \\
6 & Yuanjiadeng landslide & 15.84 & Local & InSAR & 1,2 \\
7 & Qingcaobei landslide & 19.60 & Local & InSAR & 1,2 \\
8 & Hufuqiao landslide & 24.13 & Local & InSAR & 1,2 \\
9 & Sangshuerzu landslide & 12.16 & Local & InSAR & 1,2 \\
10 & Shanentian landslide & 22.66 & Local & Ground/InSAR & 1,2,3 \\
11 & Heping Square landslide & 19.33 & Local & Ground/InSAR & 1,2,3,4 \\ \hline \hline \end{tabular}  
* In this table, engineering remedial work was classified as: 1. Drainage; 2. Retaining structures; 3. Internal slope reinforcement; and 4. Modification of slope geometry [34].  
\end{table} 
Table 3: The maximum slope displacement velocity of controlled landslides acquired by PSInSAR (PSI interferometric synthetic aperture radar) time-series analysis. Figure 6: (**a**) PSInSAR deformation rate map of the Ertunping landslide. (**b**) Crack observed in a nearby house at site P1. (**c**) Shear crack at the front edge of the Ertunping landslide. (**d**) Retaining wall at the landslide front edge. (**e**) Anchors at the landslide trailing edge. (**f**) Anti-slide piles at the landslide front edge. The Dadiping landslide lies on the bank of a tributary of the Yangtze River. Many risk elements exist on the landslide body, including an elevated highway and many buildings, which significantly increases the load on the Dadiping landslide. Both the InSAR displacement rate map and time-series of local PSs showed an obvious local deformation trend (Figure 7).