Early landslide detection based on D-InSAR technique at the Wudongde hydropower reservoir

Differential interferometric synthetic aperture radar (D-InSAR) is an effective technique for geological disaster prevention. In this study, an early landslide detection method based on the D-InSAR technique is proposed. First, SAR data are used to monitor landslide deformation in the Wudongde hydropower reservoir. Then, the ground surface deformation is derived by using the D-InSAR technique, which includes both soil and non-soil deformations. To remove the non-soil deformation, the vertical deformation filter method and slope deformation filter method for extracting soil deformations are established, and the error of D-InSAR results is analyzed. By using two methods, Permanent Scatterers InSAR and Corner Reflectors InSAR, the errors caused by the atmospheric delay are estimated quantitatively. Additionally, the relationship between the landslide deformation and the temporal-spatial change of the SAR data is analyzed, and used to identify landslides. Finally, through the proposed early landslide detection method, the Jinpingzi landslide in the Wudongde area is investigated to validate the proposed method, and the other unknown landslides in this area are also detected, which demonstrates the feasibility of the proposed method. The outcome of this study provides a workable technique for early detection of landslides in valley reservoir areas.