Chapter 1: The Coastal Area
1.1 The Coastal profile
| European Coasts - An Introductory Survey Chapter 1: The Coastal Area 1.1 The Coastal profile |
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| 5: Illustration of a sandy beach profile | 6: Sandy beach; Llanes, Spain | 7: Sandy beach at low tide; the ripples which are visible in the sand of the beach are caused by waves at high tide; Sylt, Germany |
Where ocean an land meet, some kind of natural coast forms. The profile of a particular coast depends on the local characteristics of the land (e.g. rock formation), the sediment and on local wave and current characteristics.
Beach profile
If sufficient sediment is available, a beach will develop. The form of a beach depends on wave and current
characteristics as well as on sediment characteristics. In regions where the weather conditions are strongly
dependent on the season, different profiles for summer and winter beach occur.
The reducing water depth near a coast forces incoming waves to break. Often an offshore bar is formed at this breaker line due to the local currents induced by the breaking of the waves. In the case of a shingle or pebble beach, a step is formed at the break point instead of a bar. The steepness of the beach is largely dependent on the grain size of the sediment material. Coarser sediments will result in steeper beaches. At the point of maximum wave uprush, a berm is formed. The geometry of the berms, as well as their number, is related to the size and frequency of the water level changes caused by tide and wind.
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| This page is from the book "European Coasts", produced in the framework of the Erasmus project under EC contract ICP 92-G-2013 and placed on the Internet in the framework of the PIANC-MarCom initiative on Education. |