This partial overlap of group membership can be explained by
the strong influence of the groyne fields above the sampling site
by the water quality of the River Saale. The mixing of the Saale into
the Elbe is delayed. As a result, the water of the Elbe at the sampling
site still contains about 30% water of the River Saale
(Weigold and Baborowski, 2009). In contrast to the erosion related
parameters, variables of C1-2 are mainly influenced by the polluted
tributaries Mulde and Saale. The separation of As within the
anthropogenically influenced cluster C1-2 can be explained by its
main source in the catchment area of the River Mulde. In contrast,
the remaining variables are mainly attributed to the catchment
area of the River Saale. This is comparable with the distinction
between group 3 – Saale and group 4 – Mulde of Table 1.