a case-study comparison from Denmark and Argentina
“You can only discover what you have already imagined” (Gastón Bachelard) Quote seen in “Museum of Man and the Sea”, Puerto Madryn, Argentina How much geomorphology and process understanding can we get out of SRTM and Landsat data when it comes to coastal lagoon systems? Holocene sea-level fluctuations shaped the world’s coastlines as we know them today. Sediments and surface morphology tell and conserve a part of these developments on accreting coasts and in marginal marine environments, like lagoons or marshes. Most modern coastal lagoons formed in embayments after the rapid post-glacial sea-level rise stabilized in the mid Holocene and barrier spits and beach ridges started to develop. In the BRIDGES project (2011-2014) we attempt to reconstruct coastal evolution and sea-level history for a Danish site from lagoon sediments and associated beach ridges in an environment of Holocene relative sea-level drop. In Denmark, high-resolution digital elevation models (DEM) are available for this purpose as are orthophotos and maps with an overall high temporal coverage. This allows a fine-tuned GIS-based interpretation of landforms, coastal dynamics and the processes that create them, even before setting foot out of the door. We compare this situation with a similar case from Argentina where our interpretation of the evolution of a mesoscale lagoon system is primarily dependent on readily-available low-resolution geospatial data. We present the results from an SRTM- and Landsat-based mapping of inter- and supratidal environments, barrier systems, cliffs and dune fields, which we complement with an on-site correction and GPS survey data. This allows us to quantify our error and touch upon the potential of these datasets for primary site assessment in geomorphology, lagoonal research, and sea-level studies.
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8th IAG International Conference on Geomorphology, 2013