Application of image-free control UAV aerial survey technology in emergency treatment of landslide-debris flow disaster in Lijie north hill，Zhouqu County

In recent years, UAV aerial survey technology has been widely used in the field of geological disaster prevention, especially in the emergency disposal of abrupt geological hazard. Image free UAV aerial survey technology can quickly obtain surveying and mapping data. Compared with traditional aerial survey methods, it greatly saves time cost and labor cost. In this paper, the DJI Phantom 4 RTK UAV is used to acquire and process the image free aerial survey data of landslide and debris flow disaster in Lijie North Hill landslide-debris flow disaster in Zhouqu County, Gansu Province. According to the aerial survey results, the relevant parameters such as landslide morphological characteristics and debris flow gully characteristics are quickly obtained, the signs of landslide deformation are analyzed, and the field survey data are used to evaluate and analyze the accuracy of image free aerial survey.The results show that the deformation signs, morphological characteristics and debris flow gully characteristics of landslide are consistent with the field, and the accuracy of verification points meets the data production specification of low altitude digital aerial photogrammetry (GH/Z 3003—2010). The result data can be used for the analysis of deformation characteristics of disaster body, rapid extraction of geometric parameters, and auxiliary analysis and evaluation of danger and disaster, It has a certain reference significance for the rapid acquisition of UAV mapping data in the emergency disposal of abrupt geological hazard.