Original paper
The contribution of geomorphometry to the seabed characterization of tidal inlets (Wadden Sea, Germany)
Mascioli, F.; Bremm, G.; Bruckert, P.; Tants, R.; Dirks, H.; Wurpts, A.
Zeitschrift für Geomorphologie, Supplementary Issues Volume 61 Supplementary Issue 2 (2017), p. 179 - 197
published: Nov 1, 2017
DOI: 10.1127/zfg_suppl/2017/0354
ArtNo. ESP023106102010, Price: 29.00 €
Abstract
The monitoring policies of subtidal marine areas, as regulated by the FFH and MSFD, re- quire stable measures and objective interpretation methods to ensure accurate and repeatable results. The nature of Wadden Sea inlets seabed have been investigated trough the analysis of bathymetrical and backscatter data, collected simultaneously by means of high-resolution multibeam echosounder, in conjunction with validation samples. The datasets allowed a robust approach to characterize substrate and bedforms, using objective and repeatable methods. The geomorphometric approach gives a substantial contribution to extract quantitative information on morphology and bedforms from bathymetry. DEMs of four tidal inlets have been used to calculate morphometric parameters, compare the inlets morphology and provide a classification of slope and profile curvature. Classified morphometric parameters have been applied to a detailed characterization of Otzumer Balje seabed. Very steep slopes and breaks of slope potentially related to substrate variations have been mapped and statistically investigated with respect to their depth distribution and spatial orientation. The computation of multiscale Benthic Position Index identified morphological features and bedforms at broad and fine scales. The geological and geomorphological meaning of morphometric parameters were extracted by means of quantitative comparison with backscatter intensity and samples. Backscatter was processed for radiometric corrections, geometrical corrections and mosaicking, to get intensities representative of the substrate characteristics. Within this integrated approach, it was possible to quantitatively analyse the complex morphology of subtidal areas of the Wadden Sea tidal inlets. At detailed resolution, the integration of bathymetric and backscatter data provided a bedforms and substrate characterization according to the main habitat classification schemes.
Keywords
germany • seabed mapping • swath bathymetrical systems • geomorphometry • wadden sea • tidal inlet • backscatter