FN Archimer Export Format
PT J
TI Assessing the relationship between macro-faunal burrowing activity and mudflat geomorphology from UAV-based Structure-from-Motion photogrammetry
BT 
AF Brunier, Guillaume
   Michaud, Emma
   Fleury, Jules
   Anthony, Edward J.
   Morvan, Sylvain
   Gardel, Antoine
AS 1:1;2:1;3:2;4:2,3;5:3;6:3;
FF 1:;2:;3:;4:;5:;6:;
C1 CNRS, Univ Brest, IRD, Ifremer, LEMAR, F-29280 Plouzane, France
   UM 34 CEREGE, Aix Marseille University, CNRS, IRD, INRA, Collège de France, Aix-en-Provence, France
   Laboratoire Ecologie, Evolution et Interactions des Systèmes Amazoniens (LEEISA), CNRS, Univ Guyane, Ifremer, 275 route de Montabo, 97334 Cayenne, French Guiana
C2 CNRS, FRANCE
   UNIV AIX MARSEILLE, FRANCE
   CNRS, FRANCE
UM LEMAR
   LEEISA
IN WOS Cotutelle UMR
   copubli-france
   copubli-univ-france
IF 10.164
TC 19
UR https://archimer.ifremer.fr/doc/00611/72281/87075.pdf
LA English
DT Article
DE ;Mudflat biogeomorphology;SfM photogrammetry;Crab burrows;Biofilm;Bioturbation;Amazon-influenced coast
AB Characterisation of the ecosystem functioning of mudflats requires insight on the morphology and facies of these coastal features, but also on biological processes that influence mudflat geomorphology, such as crab bioturbation and the formation of benthic biofilms, as well as their heterogeneity at cm or less scales. Insight into this fine scale of ecosystem functioning is also important as far as minimizing errors in upscaling are concerned. The realisation of high-resolution ground surveys of these mudflats without perturbing their surface is a real challenge. Here, we address this challenge using UAV-supported photogrammetry based on the Structure-from-Motion (SfM) workflow. We produced a Digital Surface Model (DSM) and an orthophotograph at 1 cm and 0.5 cm pixel resolutions, respectively, of a mudflat in French Guiana, and mapped and classed into different size ranges intricate morphological features, including crab burrow apertures, tidal drainage creeks and depressions. We also determined subtle facies and elevation changes and slopes, and the footprint of different degrees of benthic biofilm development. The results generated at this scale of photogrammetric analysis also enabled us to relate macrofaunal crab burrowing activity to various parameters, including mudflat elevation, spatial distribution and sizes of creeks and depressions, benthic biofilm distribution, and flooding duration. SfM photogrammetry offers interesting new perspectives in fine-scale characterisation of the geomorphology, benthic activity and degree of biofilm development of dynamic muddy intertidal environments that are generally difficult of access. The main shortcomings highlighted in this study are a drift of accuracy of the DSM outside areas of ground control points and the deployment of which perturb the mudflat morphology and biology, the water-logged or very wet surfaces which generate reconstruction artefacts through the sun glint effect, and the time-consuming task of manual interpretation of extraction of features such as crab burrow apertures. On-going developments in UAV positioning integrating RTK/PPK GPS solutions for image-georeferencing and precise orientation with high-quality inertial measurement units will limit the difficulties inherent to ground control points, while conduction of surveys during homogeneous cloudy conditions could reduce the sun-glint effect. Manual extraction of image features could be automated in the future through the use of deep-learning algorithms. 
PY 2020
PD MAY
SO Remote Sensing Of Environment
SN 0034-4257
PU Elsevier BV
VL 241
UT 000523958600004
DI 10.1016/j.rse.2020.111717
ID 72281
ER

EF