Comparing High Accuracy t-LiDAR and UAV-SfM Derived Point Clouds for Geomorphological Change Detection

ISPRS International Journal of Geo-Information, vol. 10, pp. 367

Abstract

Analysis of two small semi-mountainous catchments in central Evia island, Greece, highlights the advantages of Unmanned Aerial Vehicle (UAV) and Terrestrial Laser Scanning (TLS) based change detection methods. We use point clouds derived by both methods in two sites (S1 & S2), to analyse the effects of a recent wildfire on soil erosion. Results indicate that topsoil’s movements in the order of a few centimetres, occurring within a few months, can be estimated. Erosion at S2 is precisely delineated by both methods, yielding a mean value of 1.5 cm within four months. At S1, UAV-derived point clouds’ comparison quantifies annual soil erosion more accurately, showing a maximum annual erosion rate of 48 cm. UAV-derived point clouds appear to be more accurate for channel erosion display and measurement, while the slope wash is more precisely estimated using TLS. Analysis of Point Cloud time series is a reliable and fast process for soil erosion assessment, especially in rapidly changing environments with difficult access for direct measurement methods. This study will contribute to proper georesource management by defining the best-suited methodology for soil erosion assessment after a wildfire in Mediterranean environments.

Authors 6

1. Simoni Alexiou corresponding

   Agricultural University of Athens

   Affiliation as printed

   Laboratory of Mineralogy-Geology, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75, Iera Odos str., 11855 Athens, Greece

2. Georgios Deligiannakis

   Agricultural University of Athens

   Affiliation as printed

   Laboratory of Mineralogy-Geology, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75, Iera Odos str., 11855 Athens, Greece

3. Aggelos Pallikarakis

   Agricultural University of Athens

   Affiliation as printed

   Laboratory of Mineralogy-Geology, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75, Iera Odos str., 11855 Athens, Greece

4. Ioannis D. Papanikolaou

   Agricultural University of Athens

   Affiliation as printed

   Laboratory of Mineralogy-Geology, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75, Iera Odos str., 11855 Athens, Greece

5. Emmanouil Psomiadis

   Agricultural University of Athens

   Affiliation as printed

   Laboratory of Mineralogy-Geology, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75, Iera Odos str., 11855 Athens, Greece

6. Klaus R. Reicherter Aachen Institute of Neotectonics and Natural Hazards

   RWTH Aachen University

   Affiliation as printed

   Institute of Neotectonics and Natural Hazards, RWTH Aachen University, 52062 Aachen, Germany