The first-order scatter analysis is applied to assess the reliability and uncertainties of a 2D sediment transport model of the lower River Salzach. In comparison to other reliability methods (e.g. Monte-Carlo analysis), the scatter analysis has benefits in terms of time requirement since it uses considerably less simulation runs to determine a model’s reliability. In total, eight parameters are investigated including both model and river specific parameters. The results are evaluated against a reference simulation regarding bed elevation changes, bed load transport rates, grain size distribution and total riverbed evolution volume. In general, the results show a large influence of the investigated river specific parameters and transport relevant parameters. Moreover, a spatial evaluation indicates sensitive areas in regions with poor descriptive data as well as in close vicinity to weirs, ramps and lateral inflows. The applied scatter-analysis is found to be applicable to identify sensitive areas and to assess the model reliability.