Accuracy evaluation of structure from motion (SfM) photogrammetry on the measurement of typical gullies in the Loess Plateau
CHEN Xinyi1,2, SHI Yangzi1,2, YANG Yang1,2*, HUANG Tingting3, LIU Yingna1, ZHANG Guanghui1,2
(1 State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; 2 School of Geography, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China;3 Monitoring Center of Soil and Water Conservation, Ministry of Water Resources, Beijing 100053, China)
Abstract:
The structure from motion (SfM) photogrammetry was used to measure seven typical gullies in the Liudaogou catchment located in the Loess Plateau, and the accuracy in quantifying gully and gully erosion was evaluated via comparing the results to those acquired with the laser scanning (LS) and realtime kinematic (RTK) GPS. The DEM measured with SfM photogrammetry for each gully were similar with those obtained using LS and RTK GPS, and the average elevation differences ranged from -0.162 to 0.436 m when subtracting the former from the latter. SfM photogrammetry exhibited high precisions in quantifying the length, surface width, perimeter and area of each gully, and the corresponding relative errors barely exceeded ±7%. In contrast, the measurement errors of SfM photogrammetry were relatively greater for gully depth and volume, which ranged from -37.4% to 18.0%. Regarding gully erosion monitoring, both the spatial distribution of soil erosion and gully morphological parameter changes obtained by SfM photogrammetry were similar with those by RTK GPS. These results demonstrate that SfM photogrammetry can serve as a highprecision method for gully and gully erosion monitoring in the Loess Plateau.
KeyWords:
gully; gully erosion; structure from motion (SfM) photogrammetry; laser scanning; realtime kinematic (RTK) GPS; the Loess Plateau
