Abstract
In this study, we present the results of an analysis of Terrestrial Laser Scanning ( TLS) datasets, referred to multi-temporal (2013-2015) acquisition, aimed at evaluating volumetric changes and average retreat rates of the Coroglio tuff cliff, located in the western sector of Naples (Italy) in the Campi Flegrei caldera. The multi-temporal analysis was carried out in two steps: firstly, we developed a preliminary 3D Cloud-to-Cloud comparative analysis of point clouds obtained by TLS data processing, providing a view on geomorphological evolution; secondly, we obtained quantitative information by analyzing in GIS processing the differences between multi-temporal Digital Elevation Models. Finally, a morphometric analysis was carried out in order to evaluate retreat both retreat and failure rates. Four types of landslides (rock fall, debris fall, earth flow, and soil slip) have been accurately mapped in the different sectors of the cliff. The morphological analysis shows that several morphological variations have been recognized in different areas of the cliff with a maximum retreat of 8 m at the foot of the cliff due to the erosive action of the sea on poorly lithified deposits. We estimated that the average linear retreat rate related to the Coroglio cliff between 2013-2015, was equal to 0.07 m/yr; the linear retreat rate is higher (0.34 m/yr) at the base of the cliff, directly beaten by the sea waves. The results of the statistical analysis of the relationship between volume and area calculated for rock falls are consistent with the results of previous studies. Geo-structural analysis confirms that some discontinuity sets strongly control the failure kinematisms.
Highlights
Sea cliff retreat is a discontinuous process in space and time that is dominated by areal erosion processes and mass movements, which are a relevant source of natural hazard [Redweik et al 2009]
The quantification of retreat rates related to 1 and 10 year periods due to rapid erosion processes occurring along soft rock coastlines has been carried out by using airborne Light Detection and Ranging (LiDAR) technology [Young and Ashford 2006, Earlie et al 2013, 2014]
We present the results of an analysis of Terrestrial Laser Scanning (TLS) datasets, referred to multi-temporal (2013-2015) acquisition, aimed at evaluating volumetric changes and average retreat rates of the Coroglio tuff cliff, located in the western area of Naples (Posillipo hill) (Figure 1)
Summary
Sea cliff retreat is a discontinuous process in space and time that is dominated by areal erosion processes and mass movements, which are a relevant source of natural hazard [Redweik et al 2009]. In this study Terrestrial Laser Scanning (TLS) technology is used to estimate cliff volume changes and to determine linear retreat rates of sea-cliff in a specific type of soft rock, such as volcanic tuff. We present the results of an analysis of TLS datasets, referred to multi-temporal (2013-2015) acquisition, aimed at evaluating volumetric changes and average retreat rates of the Coroglio tuff cliff, located in the western area of Naples (Posillipo hill) (Figure 1). The TLS multi-temporal surveys allowed us to observe significant morphological changes in different sectors of the cliff, related to different kinds of instability phenomena. It was performed a comparison between 3D point clouds using the algorithm cloud-tocloud within CloudCompare software (CCs) [GirardeauMontaut 2015]. By considering the geological context, it was created a frontal representation of the cliff (vertical mapping), where orthophoto, geology layer and DEM data were overlayered to identify and characterize landslide and erosion processes and quantify the volumes involved in last years
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
