Leonardo: A satellite based methodology for landslide susceptibility mapping incorporating geotechnical slope stability parameters

Landslides are not only a major geomorphic agent, but can result in large economic losses to society. It is therefore important from both a process and application perspective to map areas that are likely affected by sliding. However, conventional geotechnical slope stability methods require extensive data collection, which may not always be feasible. Three questions related to this issue are addressed in this study: (1) Is it possible to use remotely sensed data to derive reasonable values for critical parameters that are required by the slope stability models? (2) Can satellite images effectively replace air photos as the primary data source? (3) Can generic geotechnical slope stability procedures be applied unchanged for susceptibility mapping or are adjustments based on local environmental conditions necessary?; To investigate these questions a well documented landslide susceptible portion of the Santa Monica Mountains of California was studied using multiple imaging and analytic techniques. The results indicate the following: (1) Geotechnical parameters can be estimated through remotely sensed data, but the effect of a local factor, in this case, fire, complicates the estimation because fire effects can alter the traditional associations between soils and vegetation. (2) Maps based on satellite images are similar to maps produced by air photos, suggesting that with respect to landslide susceptibility maps, satellite images can replace air photos. (3) While demonstrating the utility of the basic structure of the infinite slope method for landslide susceptibility mapping, the study also points to the necessity for an additional parameter, in this case, root anchoring, indicating the need for model flexibility to allow for the incorporation of locally significant variables.; This study has resulted in the development of a new methodology to evaluate landslide susceptibility, termed Leonardo. The approach incorporates satellite based imagery and local variable adjustment to allow geotechnical slope stability parameters to be determined and landslide susceptibility maps to be produced. The approach was applied to a landslide prone area of the Santa Monica Mountains with encouraging results.; More research involving the application of this approach is needed in other physical environments.