Introduction

As Cooke et al. (1993, p. 339) remarked, ‘Mobility is a very striking property of dunes, matched only by their sound-production. Sound and movement ostensibly bring dunes closer to life than anything else in the inorganic world. Movement is inexorable and can be exasperating.’ While this statement was made in the context of desert dunes, coastal dunes have also proved to be a major cause of exasperation, especially where deforestation, rabbit infestation and other factors have caused them to become reactivated. This was a favourite theme of G. P. Marsh in his Man and Nature (1864), and attempts to control errant dunes on mid-latitude shorelines, such as the Culbin Sands of north east Scotland or the Landes in south west France, go back a long way (Kittredge,1948). The migration of dunes can lead to abandonment of settlements (Figure 16.1), the overwhelming of agricultural land, the infilling of canals, and the blocking of railway lines (Figure 16.2), runways, and roads (see, for example, Han et al., 2003; Dong et al., 2004). Although movement is a natural and normal part of dune development, human pressures, such as trampling, burning, and deforestation, can make dunes less stable.

Methods of study

A whole array of methods has been developed to establish dune field activity and the rates of dune migration. Chinese workers (see Chapter 15) have successfully used ancient archival data to identify phases of dune encroachment. Topographic maps are another major source of information.