Time series of discharge (Q), dry substance (DS) and loss on
ignition (LOI) of SPM as well as total particle number concentrations
(Ntot) are presented in Fig. 2, left. Thereby, the course of dry
substance, loss on ignition and total particle number concentration
were comparable. Note that the organic content within the SPM
characterized by LOI was very high. Only at the fourth sampling
day the content of LOI within the SPM decreased. The corresponding
cluster analysis (Fig. 2, right) of the sampling days revealed two
major clusters C1 and C2. This reflects the similarities within the
period of sampling. C1 represents the early state of the flood wave
and corresponds to the re-suspension of sediments. C2 reflects the
period of sampling days, if the concentration of SPM reaches the
level below the beginning of the flood until the end of the sampling
campaign. C2 includes the flood crest. Most importantly, the flood
crest was reached long (seven days) after the maximum concentration
of SPM was measured. The SPM concentrations decreased continuously
within C2.6