The floodplain, a great landscape

Published on 13 April 2017 - Updated 16 November 2018

The history and interpretation of a river landscape is always a work in progress.

A river’s floodplain is the area it occupies or once occupied at its highest water level. Geographer Louis-Marie Coyaud is here to give us a presentation of the Loire’s floodplain, starting with the geological time scale.
“The original floodplain, I mean at the period we can really speak of the Loire as a wild river, stretched from one hillside to the other; that’s to say, from northern to southern hillside – a river that could be 2, 3, 4 or more kilometres wide.”
Rivers shape landscapes by sculpting their physical geography.
“We have what you might call a geological remnant of the earlier period – the shape of the valley itself. It’s a simple enough layout, a large U-shaped valley with a bump in the middle topped with houses and farms. The low areas to the north and south are the Loire’s former branches, one still occupied by the river and the other by the Cher, with a higher area between the two that was once a series of islands, where the city of Tours came to be built; people settled upstream and downstream alike – Saint-Pierre-des-Corps, La Riche, and all the little municipalities lying alongside the river, they’re beside it because it’s higher there than further away.”
As natural areas became inhabited areas.
“All humanised landscapes are cultural landscapes. We were responsible for exploiting the environment’s potential, the great valley I’ve just spoken of – it’s a geological inheritance. A second stratum is the landscape bequeathed by the peasant-farming era, when the land was worked as economic outlets demanded.
And then comes a contemporary period, during which a number of assets are downgraded, such as the use of low areas as grassland, as we now use very little fodder compared with bygone days, and then there are the areas you can’t build on because flood risks are too high. So we’ve got a whole set of three combinations, periods, combining to create ever more complex landscapes.”