Elaboración de un modelo para el análisis de la susceptibilidad a los movimientos de ladera mediante un sistema de información geográfica

Abstract

In this paper a landslide susceptibility model developed by the matrix method in ArcGIS for its application to the Southern basin of the Granada province is presented. The first stage of the analysis corresponds to the development of a landslide inventory database comprising data of spatial distribution and attributes of typology, degree of development, activity, etc. From elevation data a Digital Elevation Model (DEM) is obtained, from which morphological and morphometrical features are derived to Digital Terrain Model (DTM) and are used as determinant factors in the instability analysis (slope angle, attitude, etc.). Beside, other factors independent from the DEM, as lithology, are obtained by direct digitizing with its corresponding attributes on the available maps. The GIS capability permits a combination of slope instability determinant factors with landslide to build a susceptibility matrix of the studied zone. A susceptibility map is then obtained expressing a zonation of terrain units showing how prone to generate new landslide are. Given a susceptibility level, and using different GIS tools, adequate site selection for different structures may be performed or the definition of areas needing more deeper studies to introduce the necessary preventive measures in order for a reduction of the consequences of landslides. The presented model permits an automatic generation of susceptibility maps from landslide inventories or databases updated after each new activating event as new rainfall periods or earthquake occurrence.