Terrestrial, Atmospheric and Oceanic Sciences (Jan 2020)

Using UAV-SfM to monitor the dynamic evolution of a beach on Penghu Islands

  • Cheng-Hao Lu Shyh-Jeng Chyi

DOI
https://doi.org/10.3319/TAO.2019.09.25.01
Journal volume & issue
Vol. 31, no. 3
pp. 283 – 293

Abstract

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This paper explores the combination of unmanned aerial vehicle (UAV) photogrammetry and an e-GNSS survey to investigate the short-term geomorphic change and dynamic evolution of a beach system in 2015. The RMS values of the ground control points and checkpoints validate that the accuracy of UAV-SfM photogrammetry is suitable for the rapid and frequent acquisition of 3D survey data from a beach environment. We produced four digital surface models (DSMs) to determine the short-term beach topographic response to well-known western Pacific typhoons, the NE monsoon and anthropogenic construction using multitemporal surface analysis. We investigated the magnitude of the erosion caused by intense typhoons; however, the beach-dune system generally recovers through sediment transport processes in winter. Beach monitoring also reveals that the overall sand volume of this beach was reducing in short-term period. Given that the sand budget of Shanshui beach would have been continuing to reduce, this may be a negative warning to this precious tourism resource. The dynamic evolution of this beach may result in the formation of a tombolo. This study demonstrates the feasibility and survey efficiency of UAV-SfM photogrammetry for coastal monitoring, and the technique will contribute to identifying the risk to beach systems and will benefit sustainable coastal management.