Geometric Analysis of Geodetic Data for Investigation of 3D Landslide Deformations

The theoretical basis of geodetic data geometric analysis for the purpose of investigating the three-dimensional deformations of landslides is presented. A major source of empirical information on the landslide dynamics is the set of results from multiple geodetic measurements. For this purpose, a combined angular-linear and leveling network of triangles that do not overlap has been constructed in the study area. Two of the main lines of the network coincide with the lines of Bulgaria's national leveling network classes I and II. Deformation calculations have been made on the assumption of the quasi-homogeneous character of the landmasses. The deformation parameters are represented by the elements of the middle tensor of homogeneous media deformation. The spatial deformations are determined using the method of mean strain tensors for homogenous media. A data model has been developed and turned into a computer software program. The system was applied in the geodetic investigation of a landslide near the Orsoja village in the region of the Danube River, Northwest Bulgaria.