Coastal sensitivity to environmental change: a view from the beach

The coastal environment is home to a range of landforms and landscapes that include those at either end of the sensitivity scale. The soft coastal landscapes of beaches, sand dunes, and mudflats represent fast-responding and mobile geomorphic systems that are highly sensitive to environmental change. On the other hand, coastal landscapes in areas of hard rock and inherited Quaternary deposits represent relatively slow-responding systems that are, in the main, thought to be relatively insensitive to change. This paper focuses upon both groups of systems and demonstrates not only how soft coasts respond to environmental stimuli over a variety of time scales but also how this inheritance shapes subsequent development. Using mainly Scottish soft coast examples, the changes associated with sensitive coastal landscapes are assessed in terms of the past timing and magnitude of changes in both sea level and sediment economy. Declining abundance of coastal sediment has initiated a process of internal re-organisation that, because of an inherent sensitivity to sea level change and low thresholds for the forcing of change, fundamentally restricts future management options. The paper also attempts to show that hard rock coasts are also responsive to particular types of event on short time scales and examples are discussed that modify the accepted view of hard rock insensitivity to environmental change.