| Landslides are a common natural hazard that can have a major impact on life and property. The conventional geotechnical methods of preparing local and regional landslide-hazard zonation maps can be slow and costly and rely on the analysis of a finite number of locations and then inferring the remaining areas of the region to complete the maps. The application of Geographic Information Systems (GIS) technology combined with remote sensing images and digital elevation models, however, can greatly increase the accuracy of the analysis by allowing the entire region to analyzed. In addition, the application of geostatistical based soil strength data further improves the accuracy of landslide-hazard maps. The objective of this research was to utilize GIS technology combined with remote sensing and digital elevation model data to analysis landslide-hazards triggered by earthquakes. The region analyzed was the upland area adjacent to Huntsville, Alabama, located on the western edge of the Appalachian Valley and Ridge Province in the eastern United States. A standard infinite slope analysis in conjunction of the Newmark Displacement Method of analyzing earthquake-triggered landslides was used as the basis for slope stability. Vector data modeling concepts in conjunction with the applications of raster (grid) algebra functions and GIS-based spatial analysis techniques for geo-hazards mapping and risk assessment in the application of Newmark (1965) displacement analysis in a GIS environment. The method provides a framework to perform localized (i.e. pixel or cell-based) and global (i.e. entire grid) landslide-hazard analysis and risk assessment. Final output results include factor of safety maps, Newmark displacement maps, critical acceleration maps, statistical tables, graphs and charts. All soil data used in the slope stability analysis was based on geostatically based Kriging methods.; The main GIS software package used for the research was ArcView RTM GIS, developed by the Environmental Systems Research Institute (ESRI) Redlands, California. This software was customized to extend its capabilities to perform a GIS-based landslide-hazard and slope stability analysis. The final product of the customization process is an ArcViewRTM GIS Spatial Analyst Extension named LSHAZ by the author. The name LSHAZ was coined from the word Landslide-Hazard. The LSHAZ Extension adds a drop-down menu to the Menu Bar of the ArcViewRTM GIS graphic user interface.; The results of the research provide an analysis of the upland areas of Huntsville, Alabama. While the calibration of the model will need to be improved for a more precise analysis for the development of regional landslide-hazards maps, the general analysis shows the affect of earthquake intensity on the potential for generating landslides in the Huntsville area. A significant finding of this research indicates that the assumption that large seismic events such as the 1811-12 New Madrid fault and the Charleston earthquakes were required to cause the large ancient landslides that are found on the slopes of the City of Huntsville can be caused by smaller intensity earthquakes that have the potential to be generated by smaller fault zones located in Alabama and Tennessee. |
