Geograph - photograph every grid square

The River Thame (pronounced "Tame") rises in the northern Chilterns as a combination of several streams to the north of Aylesbury. It meanders for about 40 miles through Buckinghamshire and Oxfordshire, past the town named after it until it meets The Thames at Dorchester on Thames (Oxon). At most times it is a fairly insubstantial river, especially in its more northerly reaches, but after heavy rains it can become far bigger - such as after the prolonged series of downpours experienced from Dec 2013 to Feb 2014; then it bursts its banks and floods the neighbouring land - mostly farmland - in its wide shallow valley.