|(übersetzt):||Two differently exposed research areas (Graal-Müritz and Tromper Wiek), which are typical for the south-western Baltic Sea coast were investigated in order to assess the recent sediment dynamics and the processes and time scales of the regeneration of aggregate extraction sites. For both field sites, the extension of the upper and lower shoreface was evaluated from hydrodynamical and sedimentological data. Repeated sidecan sonar surveys and sedimentological investigations show a very low variability of sediment distribution patterns and grain size distributions on the lower shoreface of both research areas at seasonal time-scales. The proccesses of re-filling of 3 extraction sites, differing in respect to water depth, extraction method and extracted material were identified. Time scales of regeneration were assessed for those sites. Differences in the velocity of regeneration can be explained by the position of the extraction sites relative to the seaward limit of the shoreface, the character and availability of the potential material for regeneration and the depth of the extraction. The fundamental problem is, that aggregate extraction seaward of the shoreface implies long time spans of regeneration, while extractions on the shoreface can be re-generated quite fast; nevertheless, there is a potential of negative effects on the sediment budget. As a consequence, there is no "ideal" location for marine sediment extraction. The appropriate place for extraction should be a well-balanced compromise allowing relatively fast regeneration together with a minimized impact on the coastal sediment budget. In order to fulfill those requirements detailed knowledge about sediment budgets, availability and dynamics in the considered area is neccessary.
| ; Sandlagerstätte ; Sandabbau ; Erneuerbare Ressourcen ; Sedimentation ; Tromper Wiek ; Graal-Müritz, Baltic Sea, Germany
aggregate extraction, sediment dynamics, hydrodynamics, morphodynamics, shoreface, time scales, sidescan sonar, sedimentology