Ingeniería Civil 198/2021 | 31Cartografía de la susceptibilidad a los movimientos de ladera en la cuenca media del río Beiro, Granada

• Autores: Isabel Bandera Viñolo, Jorge David Jiménez Perálvarez
• Localización: Ingeniería civil, ISSN 0213-8468, Nº 198, 2021, págs. 31-44
• Idioma: español
• Títulos paralelos:
  • Landslide-Susceptibility Mapping in the Beiro River Middle Basin, Granada, Spain
• Texto completo no disponible (Saber más ...)
• Resumen
  • español

    En el presente trabajo se evaluó la susceptibilidad del terreno a generar movimientos de ladera mediante un análisis estadístico bivariante entre la frecuencia de ocurrencia espacial de los movimientos de ladera y los factores que los condicionan. Se elaboró un inventario que puso de manifiesto que al menos el 10,5 % de la zona esta afectada por movimientos y que estos tienen lugar principalmente en los conglomerados y arenas de la formación Alhambra a alturas inferiores a 800 m cuando la pendiente está comprendida entre 10 y 25º. Para el análisis de la susceptibilidad se consideró la litología del terreno, la pendiente, la elevación y la orientación de las laderas como factores que más contribuyen a la inestabilidad. La susceptibilidad general de la zona a los movimientos de ladera es predominantemente baja a modera, sin embargo, la zona presenta un 25,9 % de su superficie con una susceptibilidad alta o muy alta (P ≥ 25 %). La precisión del mapa de susceptibilidad obtenido se validó mediante el grado de ajuste registrando una precisión relativa del 87 %

  • English

    Landslide-susceptibility was assessed in the river Beiro middle basin, close to Granada, by means of a bivariate statistical method based on cross-tabulation between stability determining factors and landslides. The assessment of landslide susceptibility was based on the spatial probability of landslide occurrence. With this aim, a database of 70 landslides consisting of 29 slides, 26 debris flows and 15 falls was developed. Landslide inventory showed that, at least, 10.5 % of the study zone is covered by landslides, and these mainly occur in the conglomerate and sands of Alhambra formation, at elevations lower than 800 meters, in slopes between 10 and 25 degrees, and south-western slopes. The mentioned features are found close to channel-slope where elevation is lower and slope higher due to river over-excavation. Inventoried landslides are mainly shallow slides whose rupture zone fit to the surface between weathered and not-weathered soil. In any case, deep-seated slides were also to be recognized. Lithology, slope angle and slope aspect were taken in consideration as determinant factors for landslide susceptibility. The results reveal that landslide susceptibility in the area is mainly low to moderate, since 74.1 % of zone show landslide likelihood lower than 15 %. Nevertheless, 16.2 % and 9.7 % of the area show high and very high landslide susceptibility, respectively, intersecting with urbanized districts where detailed studies and preventive plans would be justified to avoid damage, for example, in extraordinary rainfall periods. Quality of the landslide susceptibility map drawn to predict landslides was validated by means of the degree-of-fit method. It was found that the association between the landslide susceptibility classes and landslides reached a relative precision of 87 % for the zones of high and very high susceptibility.