Integration of LiDAR and cropmark remote sensing for the study of fluvial and anthropogenic landforms in the Brenta-Bacchiglione alluvial plain (NE Italy)

The geomorphological study of alluvial plains takes great advantage from the integration of detailed altimetry with high-resolution images, especially in the lower-relief sectors, like those in the distal plain of the Brenta and Bacchiglione rivers near the city of Padua (mean slope 1-0.8\u2030). The LiDAR data which were specifically acquired for this research (Riegl LMS-Q560, mean density 7 points/m2, overall area 123 km2), were classified and interpolated in order to map fluvial and anthropogenic landforms. The acquisition was carried out in a moment of minimal vegetation luxuriance (March 2011), in order to minimize ground cover. The DEM (z accuracy <5-10 cm) was processed and analyzed in integration with high resolution oblique and vertical, multispectral (VIS + IR) and panchromatic aerial images. These latter were acquired during the summer crop season, with the aim of maximizing the detection of vegetation response to different soils, sediments and landforms (cropmarks). A detailed field survey was conducted with soil observation, hand augerings and description of stratigraphic sections in pits, in order to validate the remote sensing interpretations. The detailed topography allowed the identification and mapping of low rise interfluves and scarps (