“…Additional information about flow paths combined with the contribution of different ages to streamflow allows direct correlation of, for instance, water chemistry with a specific flow path, which can thus explain variations in water chemistry throughout the year (Benettin et al, 2013;Hrachowitz et al, 2016). The effect of flow paths contributing to streams has already been included in some TTs studies using particle tracking approaches (Basu et al, 2012;de Rooij et al, 2013;Gusyev et al, 2014;Modica et al, 1997;Molénat & Gascuel-Odoux, 2002;Visser et al, 2009); however, these studies focused on stationary or summer/winter TTDs. To date, particle tracking approaches have not been used to characterize dynamic TTDs for real catchments.…”