Simple scaling analysis of active channel patterns in Fiumara environment

A simple scaling analysiswas performed on experimental data relative to a riverbed reach of the Allaro Fiumara, afluvial environment typical of Southern Italy. For this purpose, a simplified geometrical approach was followed todetermine the spatial distribution of the number of active channels for the river stretch considered. In particular,the section lines crossing the braided network skeleton with distance ranging from 5 to 200m were considered.Firstly, a probabilistic analysis of the experimental data was carried out by using a truncated Poisson distributionto characterize the examined river morphologically. Afterward, a scaling analysis was performed to investigatethe existence of a possible multimodal behaviour of the number of active channels and to identify the correspondingcutoff values. For this second approach by the so-called standard coarse graining analysis, we defineda power law usable to give the probability distribution of the active channels number with varying spatial partition(distance between consecutive sections). In this way, verifying the existence of a bimodal scaling behaviourwas possible. Moreover, the cutoff limits that characterize the bimodal behaviour of the active channels werefound for all the partition distances from 5 to 100 m, while the corresponding shape and scale parameterswere also determined. A comparison of the results obtained by the statistical approach and the scaling analysiswas carried out. The variability of the characteristic parameters of the Poisson and power type laws with scalewas also investigated.