Macro-Level Assessment of Seismically Induced Landslide Hazard for the State of Sikkim, India Based On GIS Technique

International Symposium on Geohazards and Geomechanics 2015

地球科学;生态环境科学

James, Naveen^1 ; Sitharam, T.G.^2

Department of Civil Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad

500078, India^1

Department of Civil Engineering, Indian Institute of Science, Bangalore

560012, India^2

关键词: Deterministic analysis;    Deterministic seismic hazard analysis;    Digital elevation model;    Horizontal acceleration;    Nonlinear site amplification;    Seismic landslides;    Seismically induced landslide;    Spatial variations;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/26/1/012027/pdf
DOI  :  10.1088/1755-1315/26/1/012027

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

This paper presents a macro-level seismic landslide hazard assessment for the entire state of Sikkim, India, based on the Newmark's methodology. The slope map of Sikkim was derived from ASTER Global Digital Elevation Model (GDEM). Seismic shaking in terms of peak horizontal acceleration (PHA) at bedrock level was estimated from deterministic seismic hazard analysis (DSHA), considering point source model. Peak horizontal acceleration at the surface level for the study area was estimated based on nonlinear site amplification technique, considering B-type NEHRP site class. The PHA at surface was considered to induce driving forces on slopes, thus causing landslides. Knowing the surface level PHA and slope angle, the seismic landslide hazard assessment for each grid point was carried out using Newmark's analysis. The critical static factor of safety required to resist landslide for the PHA (obtained from deterministic analysis) was evaluated and its spatial variation throughout the study area is presented. For any slope in the study area, if the in-situ (available) static factor of safety is greater than the static factor of safety required to resist landslide as predicted in the present study, that slope is considered to be safe.