Los movimientos de ladera en el sector de Colmenar (Málaga)

Abstract

The field zone is located at the north side of Riogordo and Colmenar (Málaga), in the boundary between the Inner and Outer Zones of the Betic Cordilleras, where a high structural complexity is observed. The annual rainfall amounts 600 to 800 mm. A continuous and diffuse drainage occurs along the lower boundaries of the limestone formations on the underlying impervious marly formations. The middle slope angle of the area is inclined to very inclined (21 to 50%) and the lithologies cropping out in the area show very variable strengths (limestone, sandstone, silexite, breccia, clay, silt and marl). In this context a great number of mass wasting movements are recorded in the study area, mainly flows, slides and rockfalls, with deposits attaining about the 11% of the whole surface. The bigger flows and landslides have been analysed and, acording to Brunsden's classification (1973), most of these movements are more or less stabilized flows. Creeping processes are observed in gently inclined slopes on marls and clays. The preparatory factors are related to the water flow from the aquifers, the strengths of the differents lithologies, the tectonic complexity and the slope angle. The triggering factor is the rainfalls.