The Sand Engine Arjen Luijendijk Coastal Engineer / Researcher Paradigm shift in Delta Infrastructure • From: Building in Nature • Via: Building of Nature • To: Building with Nature • Eastern Scheldt storm • Maasvlakte 2 Rotterdam • Sand Engine surge barrier (1986) port extension (2008) (2011) The heart of the matter Building with Nature, a design process that : • Integrates nature and development goals • Uses natural processes • Creates added value for nature and society Building with Nature solutions soft solutions hard solutions Temperate Pilot Sand Motor IJsselmeer ES: oyster reefs Eastern Scheldt Delfland Coast foreshore nourishment as shore protection Underwater garden Tropical Coastal protection BwN design Singapore Coastal protection Singapore Sea grass Labrador Park Mangroves ‘rich levee’ focus on focus on ecosystem infrastructure functioning development Sand Engine Delfland NL Coastline Holland Coast • Decrease of natural sediment supply owing to - Sea level rise - Human interventions • Consequence: Structural erosion • Solution: Nourishments Beach nourishment Shoreline retreat Egmond (1679 – 1996) Anticipating Climate Change effects Dynamic preservation of the 1990 coastline Sand volumes: • Since 1990: 6 mln m3/yr • Since 2001: 12 mln m3/yr Prospect future since 2008: 40Tendency-85 mln m towards3/yr !! larger-scale nourishments Uncertainties on environmental effects Need for space (nature & recreation) Challenge for Province Shortage on natural recreation areas How can ambitions by realised? Challenge for the Ministry of Public Works • Traditional nourishments sinceLet’s 1970’s try a pilot that combines the wishes of different stakeholders • Shoreface nourishments since 1990’s • Now experimenting with the Sand Engine! Pilot Sand Motor Total budget 70 Meuro Realisation 2011 ~ 20 Mm3 . Reduce frequency, upscaling of volumes . Surplus of sand, distribution by tide, wind and waves Evolution 2011 - 2017 Large volume scale, emerged, concentrated at one location combination of functions (safety, recreation, nature, & knowledge development), walkable (no island), dynamic OctoberJanuary 2011 2012 JulySeptember 2011 March 2011 March2012 February 2014 2016 1 juli 2013 photos: Rijkswaterstaat; Joop van Houdt Services of the Sand Motor Extensive monitoringExtensive campaign… LS SURF BEACH Challenge the future 14 Evolution morphology Section A July 2011 B A July 2015 Section B Source: Shore Monitoring Source: Rutten et al, in press. Earth Surface Processes and Landforms. Challenge the future 15 Ecological monitoring Macrobenthos: Fish Birds Sea mammals Vegetation Insects Challenge the future 16 Recreation and Nature go hand-in-hand Challenge the future 17 Interdisciplinary research on Complex Landscape Evolution • Coastal Safety • Marine ecology • Governance • Dune formation • Terrestrial ecology • Hydrology and geochemistry Some interdisciplinary findings after 5 years • Tidal currents increase the area of sediment sorting around a sandy intervention; this influences habitat areas and fish. • The elevation, fresh water lens, and governance are important factors for growth of vegetation and dunes on emerged sandy developments. • Bed composition of the dredged material influences dune formation. • Explaining behaviour of a BwN pilot demands simultaneous, multi-disciplinary measurements. WIP: Integrated morphodynamic model for the dry beach and subaerial • Intertidal area is resolved by Delft3D and AeoLiS model • Deposition of dune lake and lagoon is now incorporated in the morphological simulation. Arjen Luijendijk, Bas Hoonhout, Rufus Velhorst and Sierd de Vries, Coastal Dynamics, 2017 Examples of other Dutch nourishments Planned for 2018: Pilot experiment in Constructed in 2015: Petten sea defence Amelander Inlet 30 mln m3 + maintenance requirement About 8 – 10 mln m3 Located near Petten Located at outer delta Is the ZM concept transferable to other locations? S-Sweden UK Jamaica Da Nang Lima Durban Yes, first ZM replicator in the UK Bacton Gas Terminal, Norfolk The Sand Engine Arjen Luijendijk Coastal Engineer / Researcher Extra slides Understanding its behaviour Forcing type: Waves WindTide Waves Waves from NW from SW Dynamic zone Cliff formation ~200,000 m3/yr Understanding its behaviour Forcing type:Waves Wind Tide Vegetation development Governance! Erosion of intertidal area Municipality Municipality Westland The Hague Dune growth rate (m3/m/yr) 25 10 Alongshore distance Understanding its behaviour Forcing type:Waves Wind Tide Sediment is transported to deeper water Tidal currents Goal: Identify the processes governing the first year evolution Modelling the evolution of the ZM First year volume changes Brute-force hindcast for 1 year Model application Wind Waves Vertical tides Surge levels Horizontal tide (currents) Morphological modelling Morphological modelling ? Morphological modelling Decadal prediction with calibrated model .