Our Changing Physical Landscape

The physical landscape we see today is the outcome of a combination of developments, some of which stretch back hundreds, even thousands, of millions of years. Four major sets of events and processes have been particularly influential. These are:

(1) the mountain building and other changes associated, over hundreds of millions of years, with global-level plate tectonics.
 
(2) denudation (i.e. erosion) and weathering processes, both those operating at the present time and those which have operated, with stunning long-term effect, over tens of millions of years. These processes have helped to alter both coastal and terrestrial landscapes.
 
(3) the impact of a series of Ice Ages, involving several glaciations and de-glaciations, within the last million years. These Ice Ages subsequently carved out the lakes, rivers and coastal marine environments which define the Irish physical landscape.
 
(4) humans have altered the physical landscape to a significant extent, primarily through farming and settlement patterns.
 
Glaciation and deglaciation have undoubtedly wrought the most far-reaching changes to the physical landscape during recent geological time. But there have been many further modifications since the arrival of humans some nine thousand years ago. Increasingly the physical landscape is being overlaid by a cultural landscape and a built environment that is the work of humans.

Many of these changes have taken place over thousands of years as lands have been colonised for farming and other forms of settlement. Most of the once widespread woods, among them those in the Glen of Aherlow and in the celebrated Kilcash in Co. Tipperary, have been cut down; wetlands have been drained; and large parts of the island have been enclosed by hedges and stone walls.
The Beara Peninsula, West Cork.
Courtesy of Carsten Clasohm.

Settlements have been created: isolated farms, villages and more substantial towns and cities. In this way, over a very long period a cultural landscape has evolved which carries the marks of many generations of settlers. Where they have built in stone or more recently in brick or concrete they have left an especially prominent imprint on the landscape.
During the twentieth century, the pace of landscape change accelerated greatly. One of the most dramatic expressions of this has been the draining and stripping of many of our lowland bogs. The activities of Bord na Mona, formed in 1946, were an economic lifeline to many midlands communities and provided an important supply of fuel and power for some decades. They have also changed the midlands landscape forever, replacing the great spongy soaking raised bogs with a brown flat stripped turfscape that has in places now been further modified by forestry.
New patterns of farming have also produced changes to the physical landscape. On some uplands, such changes include the fencing in of common land, and overgrazing and consequent erosion of hillsides as a result of higher stocking rates.

The abandonment of many small farms, and the provision of state-inspired incentives for forestry, has brought a huge increase (from around 450,000ha in 1980 to over 800,000ha in the early 2000s) in the area under woodland, with far-reaching effects on the appearance of the countryside. More subtly, the appearance of livestock has changed as new breeds have become popular: so black and white Friesians now seem universal across dairying regions like the Golden Vale between Limerick and Waterford.

Many other demands of development have contributed to producing a more prominent economic landscape. The building boom of recent decades has been dependent on a steady supply of rock, gravel and sand, and these have come from greatly enlarged quarries and from a relentless exploitation of the sands and gravels so abundantly deposited during the Ice Age. Many of the eskers and moraines of the midlands are now scarred, or in places totally removed, while limestone and other quarries may now be highly visible, if at present also highly essential, scars.

In parallel with the demands for construction are demands for disposal. The physical landscape is further modified by the waste disposal requirements of a throwaway-oriented, well-off, society. Landfill sites now overflow. In the north Dublin area of Fingal, for example, much of a once prominent local landmark, the 300 - million year old limestone mud-mound of Feltrim Hill, has been removed by quarrying, while a new hill has been created by the huge mound of now grassed-over landfill at Balleally near Rush.

Yet another requirement of modern Ireland is a large supply of energy, something that cannot yet be produced without a landscape impact. The once-prominent cooling towers of the peat-fired power stations of midland Ireland are now in old age and are being reduced to rubble. But as they disappear, prominent new expressions of our energy appetite are evident in the wind farms

Large cities impose particular demands on the surrounding countryside. Apart from its needs for building materials, waste disposal and recreation, city dwellers need space for water supply and communications - with its various ancillary sites, Dublin airport occupies some 700 hectares, while Dublin port covers some 230 hectares. The main built-up area of Dublin city now extends across 300 sq. km, and has changed the area around Dublin Bay forever.

Similar changes are in train around all our larger centres. For example, the built-up area of Galway City occupied less then 10 sq km around 1950 whereas today it encompasses at least 40 sq. km.