1. Introduction

Dunes are an important feature of Scotland’s coastline. They range in character from the pocket beaches and machair systems of the wet and wind-swept north-west coasts (Plate 1), to the long, broad belts of dunes on the east and south-west coasts that are so favoured for golf links (Plate 2). The distribution of dunes around the Scottish coast is illustrated in Figure 1.

Figure 1 Location of major Scottish dune systems

Figure 1: Location of major Scottish dune systems

Dune systems are usually fronted by sand beaches, more rarely by beaches of gravel and sand. Many of the major dune areas were originally formed several thousand of years ago from sand produced by the action of glaciers and delivered to the coast by rivers in the last Ice Age. As sea level rose to approximately its present level the sand was driven onshore and formed into dunes by onshore winds. Continual modification by waves, tides and winds has produced the situation found today. Under natural conditions dunes undergo periods of growth and erosion with each process contributing to their dynamic evolution. It is only when the coastal area becomes developed for recreation, housing, transport, industry or military facilities that these natural processes are perceived as problems needing to be managed.

From the perspective of coastal management dunes protect low lying coastal areas from flooding and also act as a buffer against erosion: they form a reservoir of sand, replenished when beach levels are high and released to nourish the foreshore during storm erosion. They are also areas of considerable scientific, conservation, landscape and recreational value. Because of these attributes they are important to a wide range of human activities, and their management is seen as an important objective in planning and usage of the coastal zone. Unfortunately, there has been a long history of poor management of coastal dunes, with unnecessary, expensive and unattractive engineering works having been undertaken that have often caused more problems than they have solved. Present day dune management in Scotland is undertaken by various groups, including local land owners, golf clubs, the Unitary Councils, Scottish Natural Heritage and the Ranger Service.

This Guide summarises the natural processes that build and erode dunes and discusses the impacts of human activities. The Guide then describes methods for the management of marine erosion, with an emphasis on methods that cause minimum disruption to natural dune evolution while still providing acceptable protection to the assets at risk. There is an underlying assumption that natural erosion of dunes is not a problem in itself, and that erosion normally only needs to be controlled to protect human assets at risk. Both the long-term and short-term perspectives on processes and management are considered. References are provided to complementary publications that describe the prevention and repair of erosion caused by wind action and people.

Scottish Natural Heritage (SNH) commissioned this Guide to assist in the practical management of marine erosion along dunes and beaches. It is written for use by all organisations and individuals involved in the practical management of coastal dune systems in Scotland, including Local Authorities, coastal consultants, the Ranger Service, landowners and golf course managers.

The Guide is not intended to provide an in depth view of coastal processes, as this subject is covered in numerous texts (see for example the Beach Management Manual, CIRIA, 1996). Nor is it intended to cover the well documented methods for the prevention or repair of damage to dunes caused by wind action, recreation or grazing (see for example the Sand Dunes Handbook, BTCV, 1996). However the Guide does recognise that management of marine erosion of dunes will often need to be carried out in combination with protection or repair of damage from other causes.

In preparing this Guide the authors visited a number of dune systems around Scotland, observing different erosion control schemes and discussing the surrounding issues with landowners, engineers, Rangers, SNH staff and recreational users of the shoreline. The authors have also reviewed UK and international literature on dune erosion and management.

The text starts with a brief description of the interactions between dunes, beaches and the sea, considering both the long-term evolution of coastal dunes in Scotland and the shorter-term changes. The many attributes of dunes, and the different perspectives that people have of them are discussed. These attributes need to be considered before undertaking any management operations, particularly if sustainable and environmentally acceptable solutions are to be devised. The responsibilities and powers of various authorities that may be involved in coastal protection or dune management schemes in Scotland are briefly summarised. Discussion then moves on to erosion management from a strategic perspective. Finally an overview is presented of the various management approaches available and a guide provided on the selection of the most appropriate methods for a given site.

The References and Bibliography include a wide range of entries that are intended to provide useful further reading. Included are regional references to the Scottish coast, guidance for dune management operations and useful background reading on coastal processes. A glossary of terms and abbreviations is included.

The remainder of the Guide is given over to Appendices, comprising:

  1. A set of stand alone summaries that describe potential erosion management approaches with sufficient information to assess applicability to specific sites and to get small projects underway. The summaries concentrate on those approaches that are low cost and will have limited impact on the environment, coastal recreation and the landscape. Major coast protection schemes are not covered in any detail as it is assumed that they would be designed by competent engineers with the support of specialists; in these cases the summaries only provide sufficient information to assist readers in assessing proposed schemes at the planning stage and to help identify elements of good practice that these schemes should embrace.
  2. A discussion of methods for monitoring coastal erosion and change in dune systems, using either low cost observational techniques or specialist techniques and measurements. Protocols and proformas are included for low cost techniques.