عنوان مقاله [English]
Landslide can be defined as mass movement of steep slopes affected by the force of gravity, which causes numerous life and property damages in the mountainous, high-rainfall and earthquake-prone regions each year. Diagnosis of the time and amount of sliding mass deformation is essential to understand the physical causes of landslide occurrence and to warning announcements for potential hazards. In this research, the relationship between displacements of the Tavan landslide in the north east of Qazvin Province and land use factor was evaluated. A network of 20 fixed points was created on various land uses inside and outside of the sliding mass to monitor the amount of displacement. The displacements of each point were measured using dual frequency GPS for 5 periods. The results of monitoring during 511 days showed that total horizontal displacement of moving points in five monitored periods was 1876 mm, with a mean monthly movement rate of 110 mm. The total vertical displacement of the moving points in the same periods was 898 mm, with a mean monthly movement rate of 53 mm. The results showed that there was a good relationship between the land use and the amount of mass displacement. Northwestern parts of the sliding mass, with the orchard land use, exprienced much greater displacements than those placed on the pasture. From the total measurements of the points with orchard land use, 70% had horizontal displacement and 40% had vertical displacement, while these percentages were reduced to 20 for pasture land use. Therefore, considering the location of the Tavan village in the vicinity and downstream of orchards region, limiting the development of orchard land use in the upstream, and conversion of irrigation system from flooding to pressurized can largely prevent the risk of subsequent landslides.