Nearshore Sandbar Classification of Sabaudia (Italy) with LiDAR Data: The FHyL Approach

Abstract

An application of the FHyL (field spectral libraries, airborne hyperspectral images and topographic LiDAR) method is presented. It is aimed to map and classify bedforms in submerged beach systems and has been applied to Sabaudia coast (Tirrenyan Sea, Central Italy). The FHyl method allows the integration of geomorphological observations into detailed maps by the multisensory data fusion process from hyperspectral, LiDAR, and in-situ radiometric data. The analysis of the sandy beach classification provides an identification of the variable bedforms by using LiDAR bathymetric Digital Surface Model (DSM) and Bathymetric Position Index (BPI) along the coastal stretch. The nearshore sand bars classification and analysis of the bed form parameters (e.g., depth, slope and convexity/concavity properties) provide excellent results in very shallow waters zones. Thanks to well-established LiDAR and spectroscopic techniques developed under the FHyL approach, remote sensing has the potential to deliver significant quantitative products in coastal areas. The developed method has become the standard for the systematic definition of the operational coastal airborne dataset that must be provided by coastal operational services as input to national downstream services. The methodology is also driving the harmonization procedure of coastal morphological dataset definition at the national scale and results have been used by the authorities to adopt a novel beach management technique.

Exploring the Dunes: The Correlations between Vegetation Cover Pattern and Morphology for Sediment Retention Assessment Using Airborne Multisensor Acquisition

“…Sediment transport from north to south determines increasing size of the dunes, and such morphological evidence has also been investigated in the submerged beach of the same area, where nearshore sandy bars have been recognized and classified [66], suggesting further relations to be explored.…”

“…Figure 14. (top) 3D topographic LiDAR visualization of the beach-dune system from north to south and (down) corresponding details of the analyses provided by plotting on the DSM profiles the cover typologies (submerged beach profiles are also shown to give a better view of the system [66]).…”

“…Moving south, these vegetation formations are characterized by the presence of pioneer juniper, which represents the transition between herbaceous phytocoenoses and those of the Mediterranean coastal vegetation of consolidated dunes. (top) 3D topographic LiDAR visualization of the beach-dune system from north to south and (down) corresponding details of the analyses provided by plotting on the DSM profiles the cover typologies (submerged beach profiles are also shown to give a better view of the system [66]).…”

A Novel GIS-Based Approach for Automated Detection of Nearshore Sandbar Morphological Characteristics in Optical Satellite Imagery

“…The study suggests a new approach based on the Relative Bathymetric Position Index (RBPI) and a combination of data processing and filtering operations designed specifically for the purpose. The Bathymetric Position Index has been widely used with bathymetric datasets for various coastal and marine applications [94][95][96][97][98][99][100][101][102][103], including sandbar extraction in the bathymetric LiDAR dataset [26], but the idea of using this metric in remote sensing images without derived bathymetry to our knowledge has never been explored before. This article illustrates that with a newly designed methodology, RBPI is suitable to discriminate nearshore morphology in non-bathymetric remote sensing images.…”

“…The use of passively sensed aerial photography for sandbar research enabled studies in larger spatial extents and hardly accessible regions [9,22] but a sparse temporal frequency. Recently, active airborne LiDAR sensors have been employed in sandbar morphology and dynamics studies [23][24][25][26], but resource-intensive data collection and processing limit the applicability of this technique either in temporal frequency or spatial extent.…”