Catchment News

Book review: Karst of Ireland – Landscape, Hydrology, Methods

David Drew, the author of this book, has over 45 years of applied research and practical work on karst in Ireland. Karst is a landscape with distinctive hydrology and landforms that arise when the underlying rock is soluble. The vast majority of karst landforms are found on carbonate rocks, such as limestones. Karst landscapes may have sinkholes, caves, enclosed depressions, disappearing streams, springs and sinkholes. The following is an extract from the introduction to the book, written by Donal Daly:

Whether you are a hydrogeologist, hydrologist, environmental scientist, catchment scientist, environmental or infrastructural engineer, planner, public health specialist, ecologist, environmental regulator or member of the public with an interest and concern for the natural environment, an understanding of the characteristics of the limestones – the predominant bedrock in Ireland – particularly those that have a significant degree of solutional features, is essential for the wise use, protection and management of the natural capital that these limestones in the Irish landscape provide. Can I justify this claim? The overriding reason is that knowing and understanding the characteristics of our natural environment is the foundation of successful environmental management. So, what are the specific reason for having a proper understanding of limestones, particularly karstified limestones and karst groundwater? Look at the evidence:

• Limestones underlie 40% of the land surface of Ireland and 45% of the Republic of Ireland, with half of this area having a significant degree of karstification.
• Karstification dictates the landscape in many areas. In upland areas, such.as the Burren, Bricklieve Mountains and Cuilcagh Mountains, karstification has provided distinctive and beautiful landscapes, that are the main basis for local tourism. In certain lowland karstified areas, such as mid Galway, mid Clare and parts of Mayo and Roscommon, an unusually dry landscape with free draining soils, a low density of streams and many stone walls, springs, sinking streams ad dolines (collapse features) are present.
• Approximately 30% of Ireland’s drinking water comes from groundwater; most of which is sourced from our limestone aquifers.
• In many areas, karst groundwater is vulnerable to pollution, particularly by microbial pathogens, and therefore can pose a health hazard for those drinking untreated water.
• The presence of one of Ireland’s unique and valuable ecosystems – turloughs – is due to karstification.

However, while there are good reasons for understanding the karst physical environment, it is perhaps the most difficult possible environment to understand, as I know after almost 40 years trying as a groundwater and catchment scientist. Why is this?

While limestones are the framework for a large proportion of the Irish landscape, it is the role of water that makes karstified areas distinctive and also difficult to characterise and to deal with. Over millions of years, it has produced landscapes of dominantly solutional origin, with bare rock sculpted by karren (small (mm-cm) solution channels), and with sinking streams, dry valleys and caves. Beneath the surface, water flow is concentrated into underground streams and conduits before issuing at large springs. In somewhat less karstified areas, water flow is in both conduits and rock fractures. The issue is that, unlike with surface water systems, we cannot ‘see’ what is happening underground and this makes conceptualisation difficult. This then poses a challenge to the hydrogeologist either looking for a water supply or developing protection measures, particularly as ‘standard’ hydrogeological investigations will usually be ineffective. It also poses a challenge to the regulator of developments in karst areas. Both must be able to conceptualise the underground effectively – the so called ‘cook book’ approach will not work.

In this book ‘Karst of Ireland: Landscape Hydrogeology Methods’ we now have a publication than can be the ‘bible’ for water scientists and engineers, particularly hydrogeologists, who will work in karst areas in the future in Ireland and abroad. Karst, karstic processes, landforms and hydrogeology are explained. Each karst region in the country is described – this information is essential reading for those undertaking development or environmental protection functions in these areas. And, importantly, the specific investigation methods needed for karst areas are described. This is a practical book for both specialists and non-specialists. All chapters contain excellent photos and illustrations to enable the ‘mental image’ of karstified areas that is needed for effective environmental management.

Without the karst applied research and practical work of David Drew for over 45 years in Ireland, this book would not be possible. The book is a fabulous legacy of one of Ireland’s foremost hydrogeologists. However, we must make it an ongoing legacy by making sure that it influences relevant decision-making in a way that benefits Irish people now and in the future. I ask that you read, learn (every time I read it, I learn more), use and enjoy.

Donal Daly

Learn more:

Karst of Ireland costs €20, and is available in hardback from the Geological Survey of Ireland online shop.

www.gsi.ie/en-ie/publications/Pages/Karst-of-Ireland-Landscape- Hydrogeology-Methods.aspx