Drainage & Geology:

The Stour flows across a variety of rock types. In the upper part of the drainage basin it flows mainly over clays. The river then flows over chalk where it is fed by two important tributaries, the River Allen and the Winterbourne. A number of chalk springs contribute to the river's flow in this section. In the lower part of the basin the Stour flows across sands and gravel's.
This geology causes the river to experience large variations in its flow between summer and winter.

These rock types give rise to a variety of different land uses. Dairy farming is important throughout the drainage basin but arable farming has been increasing in importance over the last ten years. The large urban areas of Poole, Bournemouth and Christchurch put ever-increasing pressure on the valley of the Stour and its river.

Link to Drainage & Geology Tasks