Acoustic sea bed classification of the North Sea – Sediment dynamics in the farshore environments
Measurement and evaluation of bedforms, sediment distributions, and biogenic surface structures are the initial steps to understand the dynamic processes of marine benthic ecosystems. The knowledge of active and dynamic sediment processes (especially net sediment transport) is important for the early detection of large-scale hydrographic changes, and subsequently climate change. For area-wide predictions of seabed sediment characteristics, new approaches and classification methods using the acoustic backscatter appearance of the seafloor, have been developed during the last years. However, the data comparison and application of commercial devices to other study areas are limited. In this regard, acoustic catalogues as well as standardized processing—mosaicking and data blending routines are necessary. Hence, acoustic catalogue, and data processing and measurement routines have been established by the project "WIMO" for the shallow coastal regions of the German North Sea. Similar procedures have been developed for distant and deeper water areas in the “AMIN Project”, and in the comprehensive project entitled "Development of standardized procedures for the area wide mapping of grain size distributions in the economic zone of the German North Sea and Baltic Sea" of the Federal Maritime and Hydrographic Agency (BSH). In May 2016, a guideline for “Seafloor Mapping in German Marine waters Using High-Resolution Sonars” was published by BSH and its partners: AWI, Christian-Albrechts-University Kiel (Institute of Geosciences), the Senckenberg-Institut am Meer Wilhelmshaven (Marine Sedimentology), and the Leibnitz-Institute for Baltic Sea Research Warnemünde (Marine Geology). The products of the area-wide hydroacoustic sediment distribution mapping (including hard substrates) are more detailed and accurate than existing maps (e.g. Figge 1981). They provide valuable information for offshore decision-making (i.e. fisheries management and marine engineering) or for marine detection (i.e. biotope mapping or environmental monitoring). The sediment distribution maps are available on the GeoSeaPortal of the BSH.