An increasing number of people live and work in coastal areas. The natural environment makes it an attractive place to settle. The coastal areas are also essential for the worlds industries, as they largely depend on the sea transport routes. This results in an expansion of urban and industrial developments along the coast. Consequently, questions will emerge with respect to safety, recreation, urban planning, port design and ecological impacts of human induced changes.

Coastlines are dynamic systems requiring state-of-art models to address coast related questions. This holds especially for ‘soft’ coastlines like beaches which mainly consist of sediments. The existing shoreline position is often the result of a delicate balance between eroding and accreting forces. Changes in position of the shoreline may therefore occur on different temporal scales (months to decades). The driving factors for these changes can be natural or due to human induced measures.

Both natural and human induced changes to coastlines have been studied by Deltares in a wide variety of research and engineering projects. Throughout the years, the coastline model UNIBEST-CL+ has been developed. In applications on coasts world-wide it has proven to be a flexible and easy-to-access tool capable of simulating a large variety of coastal problems. The model is able to handle complex coastline shapes, includes state-of-art sediment transport formula and has a flexible user interface.