Model studies of transport of sedimentary material in the western Baltic

Modelling of wave climate and sediment transport patterns at a tideless embayed beach, Pirita Beach, Estonia

“…A number of uncertainties are connected with inadequate knowledge of the properties of (spatial distribution of) bottom sediments and bathymetry (e.g. Kuhrts et al 2004). Also, the properties of forcing factors are usually known only approximately.…”

On the morphological long-term development of dumped material in a low-energetic environment close to the German Baltic coast

“…This site was selected because it was free of anthropogenic use and similar to official disposal sites with respect to water depth, hydrodynamical conditions, sediment type and relative distance to areas with other type of coastal utilisation. The water depths ranged from 18 to 19 m. One-year model results including events with significant storm events underline the sheltered character of the study area: flows in the lowest model layer (0-1.5m above bed) were typically between 1 and 4 cm s -1 with no priority direction (T. Seifert, personal communication), bed shear stresses generated by currents never exceeded the critical threshold for bed erosion and those generated by waves only in cases of severe storms (Kuhrts et al 2004). Natural bed sediments of the site consisted of consolidated, well-sorted, very fine sand with a medium grain-size between 110 and 120 µm.…”

“…The aim of this specific study was to estimate typical time-scales for the disappearance of the dumping mounds, to quantify the amount of material that was dispersed over time, and in this way to gather background information for an assessment of the dumping practice of the local harbour authorities. The 5 sheltered position of the dumping site (Kuhrts et al 2004, Harff et al 2005 suggested that the morphological changes should be small. To yield unambiguous information about mass balances, surface deformations, changes in surface roughness and magnitude and direction of bed sediment transport, data precision of the overall mapping system was given specific consideration.…”

“…Continuous observations of flow speeds and suspended sediment concentrations carried out at the dumping sites 1.3 m above the bed between October and December 2001 indicate that flow speeds that erode and resuspend fine sand never occurred during that period (Leipe and Bahlo 2003). As current and wave observations were not carried out, further indications on the distribution of bed shear stresses at the dumping site were drawn from numerical model computations on a 1 nautical mile grid of currents and waves from December 1992 to November 1993 (Kuhrts et al 2004, Harff et al 2005. This period was selected as it contained a longer period of significant storms and yielded flow speed and wave height distributions that were statistically comparable to a 3 nautical mile grid computation conducted for the survey period between August 2001 and October 2004 (Harff et al 2005).…”

Characteristics of suspended sediment material transport in the Ishikari Bay in snowmelt season

“…The third class of suspended sediment transport models is the quasi threedimensional models in which an asymptotic solution is introduced in advection-diffusion equation for SSM [9,10]. Suspended sediment transport in coastal areas is a three-dimensional phenomenon, that is why some three-dimensional suspended sediment transport models have been developed [11,12,13,14]. This type of models can fully describe three-dimensional distribution of sediment concentration; however, they require more computational effort than other classes.…”