The mass balance of suspended solids in a shallow lake was modelled as the net result of resuspension and settling. Four different formulations for the flux of resuspension were used. Two equations were based on the conception of wave induced resuspension, the other two used the flow field induced shear stress as the driving force for resuspension. Parameter estimations based on experimental time series of wind velocity and SS concentration produced lower least square values with the models based on flow induced resuspension. The model parameter representing settling was in reasonable accordance with the settling velocity obtained from sediment traps. The spread in results can be explained by a lack of homogeneity and horizontal transport.

A habitat suitability analysis for littoral mussel beds in the Dutch Wadden Sea was carried out. The analysis was based on the presence of mussel beds in the years [1960][1961][1962][1963][1964][1965][1966][1967][1968][1969][1970], and a number of environmental characteristics: wave action, flow velocity, median grain size, emersion times and distance to a gully border. The habitat model describes mussel bed appearance quantitatively. It predicts the distribution of mussel beds quite well, as well as the distribution of spatfall in the years 1994 and 1996. From the analysis we found that wave action (maximum orbital velocity) was the main structuring factor. A low orbital velocity was preferred. Neither very low, nor maximum flow velocities were favourable for mussel beds. Very coarse sands or silty environments were not preferred. Sites close to the low water line showed lower mussel bed appearance; when emersion time was above 50%, hardly any mussel beds could be found. The habitat suitability analysis and the construction of a habitat suitability map was performed in the framework of the discussions on a further or reduced exploitation of the tidal flats in the Dutch Wadden Sea by cockle and mussel fishery activities.

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