Long-Term Displacement Monitoring of Slow Earthflows by Inclinometers and GPS, and Wide Area Surveillance by COSMO-SkyMed Data

Roberto Vassallo,Jacopo De Rosa,Piera Gambino,Stefano Calcaterra,Nicola D’Agostino,Caterina Di Maio

doi:10.3390/geosciences10050171

Abstract

With reference to two slow earthflows in structurally complex clayey formations of the Italian southern Apennines, this paper shows the results of a long-term displacement monitoring using integrated systems of inclinometers and GPS, and their comparison with PSInSAR data. A fixed-in-place and traversal inclinometer system, first installed in 2004, recorded both the shear displacements along the slip bands, and the internal deformations of the landslide masses. A GPS network of permanent stations and benchmarks, installed in 2006–2007 in 23 strategic points of the slope, allowed for the temporal continuity of displacement monitoring. The two long series of data allowed to evaluate the factor scaling of the PSInSAR COSMO-SkyMed data, although the component of the displacement vector along the line of sight (LOS) was small. PSInSAR data allowed for the monitoring extension to houses and rigid structures that acted as reflectors. The joint data analysis allowed for the comprehension of the main features of the landslides’ kinematics.

Highlights

Earthflows in structurally complex clayey formations [1] are widely diffused in the ItalianApennines
The widespread diffusion of earthflows in clayey and flysch sequences has been reported for some areas of the southern Apennines by Revellino et al [3] and Pellegrino et al [4] who, in an area of 70 km2, recognized 484 landslides, 95% of which were of the earthflow type
Withthis the aim of enriching technical database on very slow earthflows, and analyzing their kinematics, paper presents the some experimental results on the displacements of two clayey kinematics, this paper presents the displacements of two clayey landslides landslides occurring in the Costasome della experimental

Summary

Introduction

Earthflows are the second most common type of landslides in wide hill and mountain areas of the northern Apennines, where they prevalently occur in argillaceous lithologies [2]. The widespread diffusion of earthflows in clayey and flysch sequences has been reported for some areas of the southern Apennines by Revellino et al [3] and Pellegrino et al [4] who, in an area of 70 km , recognized 484 landslides, 95% of which were of the earthflow type. The aim of studies such as that presented in this paper is to identify the main landslide mechanisms, which can give an indication of triggering factors and possible effective mitigation measures. To this aim, the monitoring of displacements plays a fundamental role. Comprehensive and long monitoring can be achieved by combining different methods: airborne LIDAR and aerial photographs [14,15], radar interferometric

Methods

Results

Conclusion