Shropshire Routes to Roots

The effect of water on the landscape is all around us, from the river flood plains to the steep sided valleys of the Shropshire hills. Water is responsible for most of the surface of what we see today. Whilst the underlying movement of the Earth slowly creates the overall landscape, water is one of the main agents in sculpting it into the forms we recognise.

There are two main ways in which water erodes the landscape:

• River water contains minerals and salts washed out of rocks higher up stream. These in turn react with the rocks in the lower reaches causing them to slowly dissolve - especially limestones.
• Water is a great carrier of all forms of abrasive materials. The sand, pebbles and boulders it carries continuously attack the stream bed and banks. Over thousands of years this eroding effect cut the steep valleys of the Long Mynd, created the wide flood plains of the Severn and Vyrnwy and gave the rounded tops to the Shropshire hills.

Water in large amounts is a very powerful force. Not only has it the abrasive power, but also its very weight can crush, push aside and flatten even the most resistant of rocks.

Perhaps water is at its most spectacular in the hills where it cascades down steep ravines, creating waterfalls, pools and gullies. It is at this stage that the young river is at its strongest and most abrasive. It is a cutting force and creates valleys.

When a river meanders across a flood plain, it creates larger and larger loops. If a sudden flood arrives it finds the weaknesses in the banks, and apart from spilling over into the surrounding land, it cuts new channels, one of which may become the new course of the river, leaving behind the old river bed as an "ox-bow" lake. That is, a detached piece of water that used to be part of the river.