Where our rivers run
The geological history of Scotland has shaped our river landscapes. Seen from above, on satellite images, Scotland has a watershed that runs down from the north of Scotland, close to the west coast. From here we have short steeper rivers descending the mountains of the west coast, and longer and larger rivers draining the eastern side of this watershed.
This current drainage pattern with short steep rivers to the west and longer rivers flowing east, first originated late in the Palaeogene geological period (65-23 million years ago). Volcanic activity, in the Palaeogene, associated with the opening of the north Atlantic also resulted in large volumes of molten rock cooling underground in a process known as underplating. This caused rapid uplift of many parts the Highlands by as much as 1 km. In general areas to the west, nearest the centre of the volcanic activity, were elevated higher than those tote east. This resulted in a broad overall pattern of land raised highest in the west and sloping away gently to the east.
Since the end of the Palaeogene, erosion by rivers, wind and also glaciers during the Ice Age, have cut steep west-flowing watercourses into the uplifted western sea-board. Water and ice flowing east, in contrast, have continued to descend down the shallower gradients towards the North Sea.