the River Thames is situated in the UK in central London
The distance from the Thames Barrier to the source of the River Thames is about 215 miles (346 kilometers). The source of the River Thames is located in the Cotswolds region in Gloucestershire, England.
London Bridge is about 150 miles downstream from the source of the river Thames.
From the mouth of the Thames at the North Sea to Teddington Lock in West London.
As far as I am familiar, there is no Argus River in Spain. If, perhaps, you meant the Tagus River (Río Tajo in Spanish), the river has its source and most of its length in Spain, but its mouth is in Portugal.
The river Thames is tidal as far upstream as Teddington Lock which is in a suburb of West London.
The Thames does not end in Oxford. It carries on meandering westward as far as Cricklade, near Cirencester.
From the estuary up as far as Teddington Lock, ie the tidal part of the Thames, it is governed by the Port of London Authority. From Teddington Lock to its source, the Environment Agency is responsible.
Tides as far up river as Teddington Lock and heavy rainfall in the rest of the river.
no, the river nile is the longest in the world
68 miles, as far as Teddington
The Thames has fresh water from its source in the Cotswolds, as nearly all rivers have fresh water from their sources.
It allowed ships to reach far inland