Editing North Sea (section)

=== Coastal management ===
{{further|Afsluitdijk|Delta Works|Flood control in the Netherlands|Thames Barrier|Zuiderzee Works}}
[[File:Afsluitdijk 1031.jpg|thumb|The [[Afsluitdijk]] (Closure-dike) is a major dam in the Netherlands]]

The southern coastal areas were originally [[flood plain]]s and swampy land. In areas especially vulnerable to storm surges, people settled behind elevated levees and on natural areas of high ground such as [[spit (landform)|spits]] and [[geest]]land.<ref name="Wefer"/>{{rp|[302,303]}} As early as 500 BC, people were constructing [[artificial dwelling hill]]s higher than the prevailing flood levels.<ref name="Wefer"/>{{rp|[306,308]}} It was only around the beginning of the [[High Middle Ages]], in 1200 AD, that inhabitants began to connect single ring dikes into a dike line along the entire coast, thereby turning amphibious regions between the land and the sea into permanent solid ground.<ref name="Wefer">{{cite book
|last=Wefer
|first=Gerold
|author2=Wolfgang H. Berger
|author3=K. E. Behre
|author4=Eystein Jansen
|title=Climate Development and History of the North Atlantic Realm: With 16 Tables
|orig-year=2002
|url=https://books.google.com/books?id=NACgnCN_jaEC&pg=PA308
|access-date=4 December 2008
|year=2002
|publisher=Springer
|isbn=978-3-540-43201-2
|pages=308–310
|archive-date=17 April 2023
|archive-url=https://web.archive.org/web/20230417083652/https://books.google.com/books?id=NACgnCN_jaEC&pg=PA308
|url-status=live
}}</ref>

The modern form of the dikes supplemented by overflow and lateral diversion channels, began to appear in the 17th and 18th centuries, built in the Netherlands.<ref>{{cite web
 |last         = Oosthoek
 |first        = K. Jan
 |publisher    = Environmental History Resources
 |title        = History of Dutch river flood defences
 |date         = 2006–2007
 |url          = http://www.eh-resources.org/floods.html
 |access-date  = 24 July 2007
 |archive-date = 26 June 2007
 |archive-url  = https://web.archive.org/web/20070626085020/http://www.eh-resources.org/floods.html
 |url-status   = live
}}</ref> The North Sea Floods of 1953 and 1962 were the impetus for further raising of the dikes as well as the shortening of the coast line so as to present as little surface area as possible to the punishment of the sea and the storms.<ref>{{cite web
|publisher = Compare Infobase Limited
|title =North Sea Protection Works – Seven Modern Wonders of World
|date =2006–2007
|url =http://www.allwondersoftheworld.com/seven-modern-wonders/north-sea-protection-works.html
|access-date = 24 July 2007 |archive-url = https://web.archive.org/web/20070525134637/http://www.allwondersoftheworld.com/seven-modern-wonders/north-sea-protection-works.html <!-- Bot retrieved archive --> |archive-date = 25 May 2007}}</ref> Currently, 27% of the Netherlands is below sea level protected by dikes, dunes, and beach flats.<ref>{{cite web
 |last         = Rosenberg
 |first        = Matt
 |work         = About.com – Geography
 |title        = Dykes of the Netherlands
 |date         = 30 January 2007
 |url          = http://geography.about.com/od/specificplacesofinterest/a/dykes.htm
 |access-date  = 19 July 2007
 |archive-url  = https://web.archive.org/web/20090201074700/http://geography.about.com/od/specificplacesofinterest/a/dykes.htm
 |archive-date = 1 February 2009
 |url-status   = dead
 }}</ref>

[[Coastal management]] today consists of several levels.<ref name="BASF">{{cite web
 |title        = Science around us: Flexible covering protects imperiled dikes – BASF – The Chemical Company – Corporate Website
 |publisher    = BASF
 |url          = http://www.basf.com/group/corporate/en/content/news-and-media-relations/science-around-us/imperiled-dikes/index
 |archive-url  = https://archive.today/20130102043157/http://www.basf.com/group/corporate/en/content/news-and-media-relations/science-around-us/imperiled-dikes/index
 |url-status   = dead
 |archive-date = 2 January 2013
 |access-date  = 16 January 2009
 }}</ref> The dike slope reduces the energy of the incoming sea, so that the dike itself does not receive the full impact.<ref name="BASF"/> Dikes that lie directly on the sea are especially reinforced.<ref name="BASF"/> The dikes have, over the years, been repeatedly raised, sometimes up to {{convert|9|m|ft}} and have been made flatter to better reduce wave erosion.<ref>{{cite web
 |last         = Peters
 |first        = Karsten
 |author2      = Magnus Geduhn
 |author3      = Holger Schüttrumpf
 |author4      = Helmut Temmler
 |title        = Impounded water in Sea Dikes
 |publisher    = ICCE
 |date         = 31 August – 5 September 2008
 |url          = http://icce2008.hamburg.baw.de/downloads/intern/Paper/BookOfAbstracts/0863_Peters.pdf
 |access-date  = 16 January 2009
 |url-status   = dead
 |archive-url  = https://web.archive.org/web/20090205005638/http://icce2008.hamburg.baw.de/downloads/intern/Paper/BookOfAbstracts/0863_Peters.pdf
 |archive-date = 5 February 2009
 }}</ref> Where the dunes are sufficient to protect the land behind them from the sea, these dunes are planted with beach grass (''[[Ammophila arenaria]]'') to protect them from erosion by wind, water, and foot traffic.<ref>{{cite web
 |title        = Dune Grass Planting
 |work         = A guide to managing coastal erosion in beach/dune systems – Summary 2
 |publisher    = [[Scottish Natural Heritage]]
 |year         = 2000
 |url          = http://www.snh.org.uk/publications/on-line/heritagemanagement/erosion/appendix_1.2.shtml
 |access-date   = 2 November 2008
|archive-url  = https://web.archive.org/web/20081212154705/http://www.snh.org.uk/publications/on-line/heritagemanagement/erosion/appendix_1.2.shtml
 |archive-date  = 12 December 2008
|url-status     = dead
}}</ref>