Analysis of coastal change : erosion and accretion along the Suffolk coast
The thesis is concerned with the rates of erosion and sedimentation along the Suffolk Coast. It includes a short outline of the historical coastal change that has occurred along the Suffolk Coast, including the erosion of Dunwich. The geology of the Suffolk Coast is described, as is its influence on the geomorphology of the cliffs and beaches of the region. The influence of man-made structures and sea defences on the area is also examined.
Environment Agency shoreline monitoring data are analysed to determine cross sectional areas and volumes of beaches and cliffs. This analysis allows the calculation of end-point (1992-2000) and year by year sedimentation and erosion rates for each shoreline monitoring point. Digitised historic Ordnance Survey 1:10560 maps are analysed using ArcView (Ordnance Survey, 1883-2000) and historic rates of coastal change at each monitoring point are extracted. Historic map data shoreline monitoring data are combined to allow direct comparison of long-term rates of change with short-term rates. Differential Global Positioning System (DGPS) surveys of Benacre Ness are used to monitor the growth, change and movement of the Ness over a period of 5 years (1995-2000). These data are combined with analysis of aerial photographic data, enabling the calculation of long and short-term rates of northward migration of Benacre Ness.
The results reveal considerable temporal and spatial variation in the rates of change. Overall erosion rates are increasing and coastal erosion in the north of Suffolk is greater than the south. Comparison of long-term and short-term data sets reveals significant increases in local erosion rates and a general increase in the rates of erosion over the past century. Future predictions of erosion and accretion rates through the use of empirical models indicate that erosion is likely to continue to be the dominant trend along the Suffolk Coast.