Document Type : Research Article
Ferdowsi University of Mashhad
Faculty of Letters and Humanities, Ferdowsi University of Mashhad
Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
Faculty of Letters and Humanities, Ferdowsi University of Mashhad, Mashhad, Iran
University of Bojnord, Bojnord, Iran
old Landslides are one of the factors of failure of slopes and the occurrence of new landslides in the world. These landslides, with their reactivation, make a great hazard to human life, infrastructures and residential structures in urban and rural areas. In this study, estimated reactivation of Hossein Abad village old landslide in North Semnan province between 2018 and 2020 using Sentinel-1 SAR data and radar interferometry (PSI).Then spatial-temporal behaviour of reactivation old landslide were analyzed using field observations, building vulnerability assessment (BVA) and spatial relationship of their damage with landslide geomorphology. The results of the PSI interferometry technique shows that the average LOS displacement of the ascending and descending tracks was -12 to 19 mm/year and -22 to 16 mm/year, respectively.This landslide started its movement in the summer of 2018, and during the period of heavy rain, in the main body and the foot of the landslide experienced the greatest vertical subsidence, with a more than − 35 mm cumulative displacemen.Also the observations of the crack pattern and the buildings vulnerability assessment confirmed the results of radar interferometry (PSI) and more than 70 percent of the buildings destroyed in the main body and at the foot of the slide ,due to the uplift and subsidence of the soil. Also, less damage has been done to the buildings in the toe of the landslide and side borders. This shows the increase of changes inside the main mass of the old landslide and its reactivation as a rotational landslide in the rainy period of 2019.