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| Titel |
Study of geomorphological changes by high quality DEMs, obtained from
UAVs-Structure from Motion in highest continental cliffs of Europe: A
Capelada (Galicia, Spain) |
| VerfasserIn |
Efrén Muñoz Narciso, Horacio García, Chema Sierra Pernas, Augusto Pérez-Alberti |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250137842
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| Publikation (Nr.) |
 EGU/EGU2017-692.pdf |
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| Zusammenfassung |
| This study analyses the geomorphological evolution of a highly dynamic coastal
environment, one of the higher cliffs in Continental Europe (A Capelada, NW Spain), using
Structure from Motion-Multi View Stereoscan techniques (hereafter referred to as
SfM-MVS). Comparing orthoimages from the last 10 years we observed several
topographical changes in one specific valley (Teixidelo). Interestingly, these changes were
caused by 2 different processes: (i) heavy coastal erosion and (ii) slow complex
landslides, working in opposite directions. The main challenge was obtaining high
quality topographical data for quantifying the changes during the last few years
using low cost-high quality techniques in remote areas. Unmanned Aerial Vehicle
platforms (drones, hereafter referred to as UAVs) and SFM-MVS offer ultrahigh-density
topographical data. Furthermore, the use of drones and SfM-MVS close range images
requires new applications in geomorphology for understanding the workflow and
limitations.
In this paper we present the 2 main results: (i) a centimeter spatial resolution DEM from
august 2016 was obtained using a @DJI Phantom 3 advanced model drone. The pictures were
processed in Agisoft PhotoScan Pro 1.2.6 version by SfM-MVS techniques, generating a
high-density point cloud (i.e. ∼2000 points/m2) with 3mm of RMSE (i.e. the point cloud was
georeferenced in a geographical coordinates system using ∼40 Ground Control Points
obtained from differential RTK-GPS and a Total Station network) and (ii) a DEM of
Differences, which compares official freely available 2010 LiDAR data (i.e. ∼2 points/m2)
with a 2016 DEM derived by UAVs-SfM, where we have observed meter-scale
elevation changes (i.e. sediment and erosion processes). During this time, 75% of the
sediment has been mobilized. The novel UAVs and SfM-MVS techniques prove to
be great for advancing the study of geomorphological processes in remote areas. |
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