Abstract
　Three dimensional displacement vectors of tracking points selected on the ground objects in a landsliding area are useful for analysis of the landslide behavior. To obtain these vectors based on a coordinate system common to whole area of the landslide, effective and safe techniques of surveying applicable to various types of ground movement are proposed. Taking three samples of different types of landslides that have occurred in Nagano prefecture, adopted surveying techniques by the total-station and the aerial-photogrammetry are reported. With the consideration of errors caused by surveying, this paper discusses the characteristics of ground movement, the discrimination of sliding blocks and the presumption of shape of underground slide surface, which are important factors for analysis of landslide mechanism.

【キーワード】：地すべり，測量，三次元地表変位ベクトル
Key words : landslide, field surveying, three dimensional ground displacement vector

*信州大学工学部社会開発工学科
Department of Architecture and Civil Engineering, Faculty of Engineering, Shinshu University