One of the most important themes in our study of rivers is the historical dimension.
Here I founda map on the net of the valley of Spercheios, in Das hellenische Thessalien by Friedrich Stählin (1924). I know nothing of Friedrich Stählin (1874-1936) but I thank him for his contribution (also thanks to: http://commons.wikimedia.org/wiki/File:The_valley_of_spercheios.jpg). Many interesting hydromorphological aspects are evident and "measurable" in this map (marshland extent, meander form, distributaries in the delta, transitional water bodies in delta, delta coastline form, key tributaries etc). The main distributary has changed, this older river mouth is very near Thermophyles (today there is a different "old river channel" and a new spillway channel - totally different situation).
Below is a gravure from 1877 (from delcampe.net) showing the the "Defile of Thermopyles" with the extensive delta marshes of the Sperchios (there are none there today!!!). This is an important image for vegetation ecologists since the vast flooded reed beds are shown clearly (the reed bed swamps are tree-less and lentic areas of open water are evident).