A deformation analysis of a dynamic estuary using two-weekly MBES surveying

A method is introduced and tested to analyze changes in depth and subaqueous dune parameter values in the complex topography of a multichannel estuary system. Periodic bedforms as represented by multibeam echo sounding (MBES) data are first separated from the raw topography in a filtering procedure. Then dune parameter class maps are determined from the bedform component of the data. These division in classes enables a segmentation of the area in regions of similar morphological behavior. The method is demonstrated on a time series of 17 two-weekly MBES data sets representing the estuary floor near Walsoorden in the Western Scheldt estuary. Two areas are analyzed in detail: a sand dump and its direct neighborhood and a more stable area, selected by the segmentation procedure.