Calibration of manual measurements of rills using Terrestrial Laser Scanning

• Morphological characteristics of rill surveyed by TLS and by manual were compared.
• Manual measures underestimate the width at the top of the cross sections.
• Manual measures underestimate the length of the rill segments.
• Calibration curves were derived and used to correct manual measurements.

This article reports the results of a field investigation aimed at comparing and verifying the agreement between two methods measuring rill morphological characteristics at the Masse experimental area. At first, the data obtained both with a manual method (profilometer) and with a Terrestrial Laser Scanner (TLS) were compared. The comparison showed that the manual measurements underestimate the width at the top of the cross sections and the length of the rill segments. Calibration curves were derived for these characteristics and were used to correct the manual data. The comparison between the corrected total length and volume and between the morphological characteristics of the measured rills at Masse showed that the power relationships available in the literature are valid also for the silty-clay soil in Masse.