Abstract:
Geological disasters occur frequently in Xiaojiang fault zone, and most of them are in high areas and covered with vegetation; so it is difficult to effectively investigate, analyze and evaluate the disasters by traditional manual investigation means, and people's life and property safety in the areas is faced with huge security risks. Here, Shaba Village in Dongchuan District was selected as the study area. SBAS-InSAR method was used to process the historical images to obtain regional time series deformation information, and UAV(Unmanned Aerial Vehicle) aerial photogrammetry method was used to obtain the real three-dimensional model of landslide mass, and the UAV arrived at the geological hazards sites for detailed investigation. Multi-scale and long time series of surface deformation monitoring and change characteristics analysis were carried out through the space-air-ground integrated method. The results indicate that ① there may be a number of areas that had already collapsed or were at risk of potential landslides. The terrain of Shaba Village is steep, and the annual deformation rate of landslide mass along the radar line of sight is between ‒4~26 mm/a. ② The ancient collapsed body in the middle of the hillside and its surrounding areas have a sliding risk, since they both are in an uplifting state, the uplift rate of the upper part (11.98 mm/a) is greater than that of the lower(9.89 mm/a), and the annual deformation rate is inconsistent. ③ The macroscopic time series deformation information of mountainous surface can be obtained through the SBAS-InSAR method, which can be used for early identification of geological hazards. Besides, the efficiency of traditional geological disaster investigation can be improved aided by UAV aerial photogrammetry to build a real three-dimensional model. Meanwhile, this method can trace the historical activity law of the deformed area, and provide important data support for disaster assessment.