Model tests of the vertical ground deformation measurement of landslide based on multiple UAV images and its application

Abstract

The safety of people and property in mountainous regions can be affected by landslides, and measurement of vertical ground formation is a vital component of landslide monitoring and forecasting. Over the past few years, UAV images have gained increasing popularity in the landslide monitoring; however, studies on the measurement accuracy of UAV image-based landslide surface deformation monitoring are relatively limited. In this study, a series of outdoor model tests are conducted to investigate the measurement accuracy of the digital difference-based software of CloudCompare, Global Mapper, and PolyWorks in UAV image-based vertical ground deformation measurement. The results indicate that when the resolution of the input UAV image is better than 3.0 cm/pixel, all the selected software can recognize the ground deformation zones with vertical ground deformation larger than 5.0 cm; under different vertical ground deformation scenarios, the vertical ground deformation measurement obtained with Global Mapper tends to be more accurate, and the medium error of the measurement ranges from 1.5 cm to 4.0 cm. Neither the medium error of measurement nor the standard deviation of measurement error is greatly affected by the magnitude of vertical ground deformation. The statistical analysis of measurement error suggests that the measurement errors of the selected software all follow normal distributions; then, based on the statistics of the measurement errors, the 95% confidence intervals of the vertical ground deformations obtained from the selected software could be obtained. Furthermore, Global Mapper software is applied to identify and measure the vertical deformation of the Dangchuan landslides in Heifangtai, and the results indicate that this software can accurately identify the landslide deformation area and locate the related ranges.

Keywords

• landslide
• vertical ground deformation
• uav images
• model test
• digital difference