HR satellite imaging and borehole monitoring of landslides in Daunia, Italy

Abstract

We examine the instability of slopes in a catchment traversed by a 11 km long mid-slope road, characterized by the widespread presence of clay materials with poor geotechnical properties. High Resolution (HR) multispectral satellite imagery is used to provide focus on the landslides affecting the road and on their close association with poorly drained sites (wet areas, concentration of roadway runoff). The origin of many wet areas mapped from the satellite imagery is linked to the seasonally persistent high groundwater levels revealed through the piezometer monitoring. The remotely sensed data integrated with the in situ controls and subsurface monitoring show that the slopes traversed by the road are poorly drained and marginally stable. Thus even relatively moderate rainfall events (e.g. several tens of mm of rain in few days) can lead to landslide re-activations, which typically occur in the second half of fall and winter periods characterized by higher groundwater levels. © Springer-Verlag Berlin Heidelberg 2013.