Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

Surface topography can significantly affect earthquake ground motions, as suggested by many examples of unexpected damage suffered by buildings located on the top of hills, on ridges or along slopes. European and Italian seismic codes suggest topographic aggravation factors in the 1 – 1.4 range to be applied to seismic actions, depending not only on simple morphologic parameters (average slope angle, width and height of the relief) but also on the type of relief (isolated cliff or ridge) and on the location of the site relative to the relief. Furthermore, strongly irregular topographies should be dealt with by a specific study. To provide a practical tool for the identification of critical topographic sites, analyses of high resolution digital elevation models (DEM), with the support of Geographic Information Systems (GIS), are presented in this paper. Simple GIS functions are used to classify critical ranges of inclination, while the identification of valleys and ridges requires more complex procedures. A comparison of different methods for their identification is presented in this work, aiming at finding the most suitable ones for seismic microzonation analyses. Once the critical conditions are synthesized into GIS layers, their proximity to inhabited centres or strategic structures are checked. The resulting maps can be used for topography-related seismic risk assessment at large scale. We present two examples of application of this procedure, with particular attention to the small historical centres located on the Apennine mountains in Central and Southern Italy.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Fifth Conference

Publisher

Missouri University of Science and Technology

Publication Date

5-24-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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May 24th, 12:00 AM May 29th, 12:00 AM

GIS-Based Identification of Topographic Sites in Italy with Significant Ground Motion Amplification Effects

San Diego, California

Surface topography can significantly affect earthquake ground motions, as suggested by many examples of unexpected damage suffered by buildings located on the top of hills, on ridges or along slopes. European and Italian seismic codes suggest topographic aggravation factors in the 1 – 1.4 range to be applied to seismic actions, depending not only on simple morphologic parameters (average slope angle, width and height of the relief) but also on the type of relief (isolated cliff or ridge) and on the location of the site relative to the relief. Furthermore, strongly irregular topographies should be dealt with by a specific study. To provide a practical tool for the identification of critical topographic sites, analyses of high resolution digital elevation models (DEM), with the support of Geographic Information Systems (GIS), are presented in this paper. Simple GIS functions are used to classify critical ranges of inclination, while the identification of valleys and ridges requires more complex procedures. A comparison of different methods for their identification is presented in this work, aiming at finding the most suitable ones for seismic microzonation analyses. Once the critical conditions are synthesized into GIS layers, their proximity to inhabited centres or strategic structures are checked. The resulting maps can be used for topography-related seismic risk assessment at large scale. We present two examples of application of this procedure, with particular attention to the small historical centres located on the Apennine mountains in Central and Southern Italy.