Long-term morphological variations of a sandbank system

Long-term variations in nearshore coastal morphology can be an important influence in shaping the strategy for management of coastal regions. The design of sea defences, ports and harbours are reliant on adequate understanding of the long-term evolution of coastal morphology. Statistical techniques, known as eigenfunction or empirical orthogonal function (EOF) methods, have been applied to a series of historical bathymetric surveys of a nearshore sandbank system covering a period of almost 150 years. The sandbanks cover an area measuring approximately 30 × 10 km and lie several kilometres offshore from Great Yarmouth which is situated on the east coast of the United Kingdom. This paper presents the results of a statistical analysis of the data. The results provide quantitative support for the presence of quasi-periodic variations in the sandbank morphology of periods that are germane to coastal planning.