scholarly journals A strategy to address the task of seismic micro-zoning in landslide-prone areas

2013 ◽  
Vol 35 ◽  
pp. 23-35 ◽  
Author(s):  
G. Vessia ◽  
M. Parise ◽  
G. Tromba

Abstract. As concerns landslide prevention and mitigation policies at the urban scale, the ability of Geographical Information Systems (GIS) to combine multi-layered information with high precision enables technicians and researchers to devote efforts in managing multiple hazards, such as seismically induced instability in urbanized areas. As a matter of fact, many villages in the Italian Apennines, placed near high-energy seismic sources, are characterized by active sliding that are seasonally remobilized by rainfall. GIS tools can be useful whether accurate Digital Elevation Models (DEM) are available and detailed mechanical and hydraulic characterization of superficial deposits over significant portion of the urban territory is undertaken. Moreover, the classic methods for estimating the seismic-induced permanent displacements within natural slopes are drawn from the generalization of Newmark's method. Such method can be applied to planar sliding mechanism that can be considered still valid wherever shallow landslides are generated by an earthquake. The failure mechanism depends on the mechanical properties of the superficial deposits. In this paper, the town of Castelfranci (Campania, southern Italy) has been studied. This small town, hosting two thousand inhabitants, suffers from the seasonal reactivation of landslides in clayey soil deposits due to rainfall. Furthermore, the site is seismically classified by means of the peak ground acceleration (PGA) equal to 0.246 g with respect to a 475 yr return period. Several studies on the evolution of slopes have been undertaken at Castelfranci and maps have been drawn at the urban scale not taking into any account the seismic hazard. This paper shows possible seismically induced hazard scenarios within the Castelfranci municipal territory aimed at microzonation of level 2, by estimating the slope permanent displacements comparable to those caused by the strongest historical seismic event that hit this area: the 1980 Irpinia earthquake. To this aim, geotechnical characterization of local soils collected over the last 25 yr by local technicians have been used to predict possible permanent displacements by means of Newmark's sliding block approach. Two simplified relationships relating peak ground acceleration and Arias intensity to permanent displacements have been used and compared. Although similar results are drawn, the two analyses point out the most hazardous sectors of the Castelfranci urban area.

2015 ◽  
Vol 31 (3) ◽  
pp. 1813-1837 ◽  
Author(s):  
Jing Zhu ◽  
Davene Daley ◽  
Laurie G. Baise ◽  
Eric M. Thompson ◽  
David J. Wald ◽  
...  

We describe an approach to model liquefaction extent that focuses on identifying broadly available geospatial variables (e.g., derived from digital elevation models) and earthquake-specific parameters (e.g., peak ground acceleration, PGA). A key step is database development: We focus on the 1995 Kobe and 2010–2011 Christchurch earthquakes because the presence/absence of liquefaction has been mapped so that the database is unbiased with respect to the areal extent of liquefaction. We derive two liquefaction models with explanatory variables that include PGA, shear-wave velocity, compound topographic index, and a newly defined normalized distance parameter (distance to coast divided by the sum of distance to coast and distance to the basin inland edge). To check the portability/reliability of these models, we apply them to the 2010 Haiti earthquake. We conclude that these models provide first-order approximations of the extent of liquefaction, appropriate for use in rapid response, loss estimation, and simulations.


2020 ◽  
Vol 11 (2) ◽  
pp. 1-25
Author(s):  
Shiv Shankar Kumar ◽  
Pradeep Acharya ◽  
Pradeep Kumar Dammala ◽  
Murali Krishna Adapa

This chapter presents the seismic vulnerability of Kathmandu City (Nepal), based on Nepal 2015 earthquake, in terms of the ground response and liquefaction potential. The spatially well-distributed 10-boreholes and ground motions of Mw 7.8 Nepal 2015 earthquake recorded at five different stations were adopted for the analysis. The range of peak ground acceleration and peak spectral acceleration were in the order of 0.21g-0.42g and 0.74g-1.50g, respectively. Liquefaction potential of the sites were computed using both semi-empirical approach and liquefaction potential index (LPI). LPI shows that the 6 sites out of 10 sites are at high risk of liquefaction.


Author(s):  
D. Al-Dogom ◽  
K. Schuckma ◽  
R. Al-Ruzouq

<p><strong>Abstract.</strong> Assessing and analyzing the spatial distribution of earthquake events aids in identifying the presence of clustering and reveals hot and cold spots across the study area. Combining the spatial analysis of earthquake events with other geographical and geophysical parameters leads to more understanding of the vulnerability of critical infrastructure and the demographics of the affected population. This study will use Geographical Information Systems (GIS) to examine the spatiotemporal occurrence of earthquake events throughout the Arabian plate and their effect on the United Arab Emirates (UAE). Spatial pattern analysis techniques, including Moran I and Getis–Ord Gi*, were applied to 115 years of earthquakes (1900&amp;ndash;2015) that have occurred throughout the Arabian plate. The directional distribution (standard deviational ellipse) of earthquake magnitudes was analyzed to determine the spatial characteristics and the directional tendency of the earthquakes throughout the Arabian plate. Afterword, geophysical parameters of UAE, specifically Peak Ground Acceleration (PGA), fault line distance, slope, soil type, and geology were ranked, weighted based on its contribution and combined using an Analytic Hierarchy Process (AHP) to identify and locate seismic hazard zones. The resulted Seismic Hazard Zonation Map (SHZM) was classified to five hazard zones ranging from very high to very low. It has been found that Fujairah city sited in the “very High” zone, Sharjah and Dubai cities located from “High” to moderate zones while Abu Dhabi city stands relatively far from seismic hot spots and major faults and placed in the low seismic hazard zone. The results of this study could help improve urban planning and emergency mitigation strategies in UAE.</p>


2006 ◽  
Vol 22 (2) ◽  
pp. 491-509 ◽  
Author(s):  
Jaewook Park ◽  
Nobuoto Nojima ◽  
Dorothy A. Reed

The performance of an urban electric utility distribution system was evaluated for the February 2001 Nisqually earthquake. The restoration rate of the lifeline following the event was determined; the distribution of outage durations was estimated; and correlations between lifeline damage and instrumental Modified Mercalli intensity, peak ground velocity, and peak ground acceleration values were ascertained using a GIS (geographical information systems) approach. Using a logit regression analysis, a fragility curve was developed for the lifeline in a manner similar to O'Rourke's formulation of water-line performance (O'Rourke et. al. 2000). Extrapolation of the model to the Seattle Fault earthquake scenario was made to demonstrate its feasibility for prediction.


2019 ◽  
Vol 2019 ◽  
pp. 1-26 ◽  
Author(s):  
Ivan Banović ◽  
Jure Radnić ◽  
Nikola Grgić

Using a shake-table, the effects of several stone pebble layer parameters (the layer thickness, the fraction of pebbles, the pebble compaction, the pebble moisture, the vertical contact stress below the foundation, and the effect of repeated excitations) on layer aseismic efficiency were investigated. For each considered parameter, a model of a rigid building on an aseismic layer was exposed to four different accelerograms, with three levels of peak ground acceleration (PGA), while all other layer parameters were kept constant. For each test, the characteristic displacements and accelerations were measured. Based on the test results, the main conclusions regarding the effect of the considered parameters on the effectiveness of the adopted aseismic layer are given.


2013 ◽  
Vol 1 (5) ◽  
pp. 4511-4538 ◽  
Author(s):  
M. Panahi ◽  
F. Rezaie ◽  
S. A. Meshkani

Abstract. The objective of the study was to evaluate the seismic vulnerability of school buildings in Tehran city based on analytical hierarchical process (AHP) and geographical information systems (GIS). Therefore, to this end, the peak ground acceleration, slope and soil liquefaction layers were used for preparation geotechnical map. Also, the construction materials of structures, year of construction, their quality and seismic resonance coefficient layers were defined as major affecting factors in structural vulnerability of schools. Then, the AHP method was applied to assess the priority rank and weight of criteria (layers) and alternatives (classes) of each criterion through pair wise comparison in all levels. Finally, geotechnical and structural spatial layers were overlaid to prepare the seismic vulnerability map of school buildings in Tehran city. The results indicated that only in 72 schools (about 3%) out of 2125 schools in the study area, the destruction rate is very high and therefore their reconstruction should be considered.


2012 ◽  
Vol 32 (5) ◽  
pp. 932-943 ◽  
Author(s):  
Hugo A. S. Guedes ◽  
Demetrius D. da Silva

The aim of this study was to compare the hydrographically conditioned digital elevation models (HCDEMs) generated from data of VNIR (Visible Near Infrared) sensor of ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), of SRTM (Shuttle Radar Topography Mission) and topographical maps from IBGE in a scale of 1:50,000, processed in the Geographical Information System (GIS), aiming the morphometric characterization of watersheds. It was taken as basis the Sub-basin of São Bartolomeu River, obtaining morphometric characteristics from HCDEMs. Root Mean Square Error (RMSE) and cross validation were the statistics indexes used to evaluate the quality of HCDEMs. The percentage differences in the morphometric parameters obtained from these three different data sets were less than 10%, except for the mean slope (21%). In general, it was observed a good agreement between HCDEMs generated from remote sensing data and IBGE maps. The result of HCDEM ASTER was slightly higher than that from HCDEM SRTM. The HCDEM ASTER was more accurate than the HCDEM SRTM in basins with high altitudes and rugged terrain, by presenting frequency altimetry nearest to HCDEM IBGE, considered standard in this study.


2006 ◽  
Vol 61 (3) ◽  
pp. 181-190 ◽  
Author(s):  
N. J. Schneevoigt ◽  
L. Schrott

Abstract. Although the global importance of high mountains is increasingly being recognised, their geomorphic process System has not been completely understood as yet. While Systems theory and geographical information Systems (GIS) approaches have been long-serving in alpine geomorphology, the implementation of remote sensing (RS) tools is still rare. However, objeet-oriented image analysis lends itself to alpine applications, as it unites the benefits of RS and GIS. The Systems approach and the object-oriented classification of an ASTER satellite scene with digital elevation information are parallelized in the Reintal (Bavarian Alps). In a hierarchical, multiscale data segmentation and Classification, alpine landforms can be detected with high accuracy. Hence, RS techniques represent a valuable tool for high mountain geomorphology.


Author(s):  
José Francisco Zelasco ◽  
Gaspar Porta ◽  
José Luis Fernandez Ausinaga

A typical way to build surface numerical models or Digital Elevation Models (DEMs) for Geographical Information Systems (GIS) is by processing the stereo images obtained from, for example, aerial photography or SPOT satellite data. These GIS can perform many computations involving their geographic databases. The quality control of a geographic database, and in particular the topological and geometric integrity, are, therefore, important topics (Guptill & Morrison, 1995; Harvey, 1997; Laurini & Milleret-Raffort, 1993; Ubeda & Servigne, 1996). The geometric quality control of the stored DEM is what we are concerned with here. “Quality” means the geometric precision measured in terms of the difference between a DEM and a reference DEM (R-DEM). We assume the R-DEM is a faithful model of the actual surface. Its point density may be greater than the DEM point density.


Sign in / Sign up

Export Citation Format

Share Document