Fig. 1.

Arno River basin’s land coverage. Data from Copernicus Land Monitoring Service (CLC2018). The map is realized by using QGIS software (v. 3.12). The numbers refer to the location of the sampling stations along the river. The tributary between stations 2 and 3 is the Canale della Chiana; the tributary between stations 7 and 8 is the Ombrone Pistoiese; the tributary between stations 10 and 11 is the Usciana. The map on the left bottom corner shows the location of the coastal stations. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)