Limited intervention https://coastal-management.eu/ en EXAMPLE: Wallasea Island Wild Coast project (UK) https://coastal-management.eu/measure/example-wallasea-island-wild-coast-project-uk <span class="field field--name-title field--type-string field--label-hidden">EXAMPLE: Wallasea Island Wild Coast project (UK)</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="https://coastal-management.eu/user/6" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">nst</span></span> <span class="field field--name-created field--type-created field--label-hidden">Mon, 01/16/2017 - 13:39</span> <div class="field field--name-field-adressed-disks field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/36" hreflang="en">Erosion</a></div> </div> <div class="field field--name-field-type-of-measure field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/60" hreflang="en">Channel, Coastal and Floodplain Works</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/59" hreflang="en">Water flow regulation</a></div> </div> <div class="field field--name-field-type-of-coastal-defence-st field--type-entity-reference field--label-hidden field__item"><a href="https://coastal-management.eu/taxonomy/term/73" hreflang="en">Limited intervention</a></div> <div class="field field--name-field-colour field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/65" hreflang="en">Ecosystem based approach</a></div> </div> <div class="clearfix text-formatted field field--name-field-short-descr field--type-text-long field--label-hidden field__item"><p>The aim of the Wallasea Island Wild Coast project is to recreate a natural intertidal coastal marshland to combat the threat of climate-induced coastal flooding. The recreated mudflats, salt and brackish marshes, saline lagoons, and pastures will provide a range of habitats for coastal birds and other wildlife on the Essex coast.</p></div> <div class="clearfix text-formatted field field--name-field-information-source field--type-text-long field--label-hidden field__item"><p><a href="https://www.rspb.org.uk/our-work/our-positions-and-campaigns/campaigning-for-nature/casework/details.aspx?id=tcm:9-235089">Based on information from the Royal Society for the Protection of Birds (RSPB)</a></p></div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><h4>General description</h4> <p>The project uses a technique known as “<a href="http://coastal-management.eu/measure/managed-realignment">managed realignment</a>” to recreate an intertidal habitat through the breaching of existing seawalls at strategic locations. These breaches, or holes, allow sea water in, and various kinds of ecosystems can be created depending on the height of the land being flooded. The land of the Wallasea Island will be heightened and extended using the clay, chalk, and gravel excavated from new underground rail line connections in central London. In total, nearly 1500 acres of tidal wildlife habitat will be transformed or created new, including approximately 133ha of mudflat, 276ha of salt marsh, 53ha of saline lagoons, 11ha of brackish marsh, 160ha of grassland, and 15ha of rotational arable fields.</p> <p>Historically, Wallasea ‘Island’ comprised as many as five individual salt marsh islands. When seawall defences were added to the area to prevent coastal erosion, the landscape eventually evolved into the shape that can be seen today.</p> <p>Since 2008, the Wallasea Island Wild Coast project has been in partnership with an underground rail line development project called Crossrail. The clay, chalk, and gravel excavated from their tunnelling in central London will be reused to heighten and transform the coastlines of the Wallasea area. The addition of these materials to raise land and extend coastlines is expected to allow approximately 2.1Mm<sup>3</sup> of tidal water to enter the area once the sea walls are breached. This would require around 7.5Mm<sup>3</sup> of imported fill material. The construction schedule to achieve the objectives of the managed realignment plan is determined by the delivery schedule of the materials from the Crossrail project, and is planned between 2016 and 2019.</p></div> <div class="clearfix text-formatted field field--name-field-second-descrip field--type-text-long field--label-hidden field__item"><p>The site is located near one of the world’s most important estuaries and one of Europe’s largest economic regeneration zones: the Thames Gateway. The Crouch and Roach Estuaries bordering Wallasea Island have been recognized, under the European Union Directive on the Conservation of Wild Birds, as a Special Protection Area, a Special Area of Conservation, and a Wetland of International Importance through the Ramsar Convention.</p> <p>In July 2009, the final design of the project received planning approval. Local authorities, yacht clubs, and various organizations were publically consulted and included in developing and designing the project plan.</p> <h4>Innovative Aspects</h4> <p>The Wallasea Island Wild Coast project is a bold initiative to address the alarming amount of coastal change that has happened in this region of Europe. Over the past 400 years, the Essex coast has lost over 91% of its intertidal salt marshes due to accelerating coastal erosion and competition with agriculture for land. The project has set a high standard for 21<sup>st</sup> century conservation and engineering efforts, and is at a scale never before attempted in the UK. It jointly considers ecological and economic factors, for the benefit of future visitors, wildlife, and local community members for decades to come.</p> <p>Perhaps the most innovative aspect of the project is the landmark partnership and collaboration between the project operators, the Royal Society for the Protection of Birds (RSPB), and the underground rail development project Crossrail. By deciding to reuse the excavated materials from London’s new underground connections to achieve the managed realignment objectives of Wallasea Island, the two projects set a global standard for how waste material from large-scale infrastructure projects does not have to be disposed of in a landfill. Instead, excavated soils, clays, and rocks can provide flood protection to coastal communities and refortify coastal ecosystems. Equally, the project cooperation showed that it is possible to transport large amounts of excavation spoil from London to the Essex coast in a safe and reliable way.</p></div> <div class="clearfix text-formatted field field--name-field-key-lessons field--type-text-long field--label-above"> <div class="field__label">Key lessons learnt</div> <div class="field__item"><p>The Wallasea Island Wild Coast project showed that despite the challenges, major land realignment can be undertaken in a sustainable way. The use of excavated materials from the London Crossrail project also illustrated a mutually beneficial solution for both stakeholder groups and is an example of cooperation that leads to smart solutions for the benefit of the environment.</p></div> </div> <div class="field field--name-field-relevant-case-studies-and- field--type-entity-reference field--label-above"> <div class="field__label">Relevant case studies and examples</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/measure/marsh-vegetation-intertidal-and-coastal-zone" hreflang="en">Marsh vegetation in intertidal and coastal zone</a></div> </div> </div> <div class="field field--name-field-further-readings field--type-link field--label-above"> <div class="field__label">Further Readings</div> <div class="field__items"> <div class="field__item"><a href="http://www.rspb.org.uk/Images/ES_tcm9-290549.pdf">PDF: Documentation about the project</a></div> </div> </div> <div class="field field--name-field-measure-category field--type-entity-reference field--label-above"> <div class="field__label">Measure category</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/76" hreflang="en">Mitigation</a></div> </div> </div> Mon, 16 Jan 2017 12:39:10 +0000 nst 227 at https://coastal-management.eu Marsh vegetation in intertidal and coastal zone https://coastal-management.eu/measure/marsh-vegetation-intertidal-and-coastal-zone <span class="field field--name-title field--type-string field--label-hidden">Marsh vegetation in intertidal and coastal zone</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="https://coastal-management.eu/user/27" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">giacomo.cazzola</span></span> <span class="field field--name-created field--type-created field--label-hidden">Sun, 09/11/2016 - 21:51</span> <div class="field field--name-field-adressed-disks field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/53" hreflang="en">Riverine or slow rise floods</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/35" hreflang="en">Estuarine floods</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/37" hreflang="en">Coastal floods or storm surges</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/36" hreflang="en">Erosion</a></div> </div> <div class="field field--name-field-type-of-measure field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/58" hreflang="en">Natural flood, runoff, catchment management</a></div> </div> <div class="field field--name-field-type-of-coastal-defence-st field--type-entity-reference field--label-hidden field__item"><a href="https://coastal-management.eu/taxonomy/term/73" hreflang="en">Limited intervention</a></div> <div class="field field--name-field-colour field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/65" hreflang="en">Ecosystem based approach</a></div> </div> <div class="clearfix text-formatted field field--name-field-short-descr field--type-text-long field--label-hidden field__item"><p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">Saltmarsh and mudflats are usually located together with mudflats in front of the saltmarsh. Saltmarsh vegetation and saltmarsh creeks help manage floods by dissipating wave and tidal energy.  They are valuable barriers to the risks of flood, as they dissapte wave and tidal energy. Saltmarshes used in combination with other measures can have beneficial outcomes to managing climate change impacts. Even a small width of fronting saltmarsh can significantly reduce the height of sea walls required to achieve the same level of protection and thus also reduce initial construction costs. Having saltmarsh fronting will also significantly reduce maintenance costs due to the reduced exposure to wave and tidal energy.</span></p></div> <div class="clearfix text-formatted field field--name-field-information-source field--type-text-long field--label-hidden field__item"><p><a href="https://www.sepa.org.uk/media/163560/sepa-natural-flood-management-handbook1.pdf">Based on kindly provided information by SEPA's Natural Flood Management Handbook (p. 52ff.)</a></p></div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><h4><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">Where is restoration of saltmarsh appropriate?</span></h4> <p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">Saltmarsh and mudflats are unique habitates comprised of fine grain sediments (silts and clays) that settle out of the water colomn in calm areas or where there is low water speed. Saltmarsh is usually found in estuaries or sheltered areas such as bays or at the head of sea lochs. The overall shape of the estuary or bay determines the location and extent of saltmarsh and mudflat. Development of mature saltmarsh typically takes between 40 to 80 years. However, this will not be possible in all locations, particularly where existing protection structures restrict the establishment of higher zones.</span></p> <p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">Determining whether conditions are good for the development of saltmarsh is difficult. In addition to naturally occurring physical processes, the nutrients determine if conditions are favourable for the establishment of saltmarsh and chemical pollutants can affect whether saltmarsh can colonise mudflat. Therefore, it is generally better to increase the extent or facilitate the relative stability of existing saltmarsh, rather than attempt to establish this habitat in new areas where it has not been present historically.</span></p></div> <div class="clearfix text-formatted field field--name-field-second-descrip field--type-text-long field--label-hidden field__item"><h4><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">Restoring saltmarsh</span></h4> <p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">The size of the saltmarsh habitat is often determined by the tidal range. To increase the size or space for a saltmarsh habitat, it can be extended seawards or re-aligned by moving existing coastal structures inland. </span></p> <p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">According to Forbes et al. (2015), </span><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">sediment can be placed at various levels in the morphological profile:</span></p> <ul> <li><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">a thin layer of sediment can be sprayed over existing habitat to increase existing intertidal elevation; or</span></li> <li><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">sediment can be placed in the intertidal zone to artificially increase the intertidal area; or</span></li> <li><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">sediment can be placed in the sub-tidal zone to reduce erosion from intertidal margins</span></li> </ul> <p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">To encourage sediment to settle and saltmarsh to establish the following techniques can be used:</span></p> <ul> <li><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">Brushwood fascines/groynes: Small wooden posts erected in parallel rows and in-filled with brushwood to create a small fence. Other materials can be used but brushwood has been found to be the most durable. The best orientation is generally at right angles to the foreshore.</span></li> <li><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">Polders: Brushwood fences or fascines are erected that enclose a width of mature marsh with a similar sized seaward extent of mudflat. Ditches are dug to collect deposited sediment, which is then piled onto banks between the ditches.</span></li> </ul> <p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">Saltmarsh can be left to naturally colonise the mudflats. However, unless there are good natural sources of local seeds, planting or sowing will be needed. Planting has generally been shown to be more effective than sowing. </span></p> <p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">The majority of the costs associated with establishing saltmarsh will be the associated costs of re-charge or managed realignment required. If polders are used, the costs of establishing and maintaining these can also be significant. </span></p></div> <div class="field field--name-field-download-factsheet field--type-file field--label-inline clearfix"> <div class="field__label">Download Factsheet</div> <div class="field__item"> <span class="file file--mime-application-pdf file--application-pdf"> <a href="https://coastal-management.eu/sites/default/files/2016-12/SEPA-NFMH-52-54.pdf" type="application/pdf; length=167227">SEPA-NFMH-52-54.pdf</a></span> </div> </div> <div class="field field--name-field-relevant-case-studies-and- field--type-entity-reference field--label-above"> <div class="field__label">Relevant case studies and examples</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/measure/example-wallasea-island-wild-coast-project-uk" hreflang="en">EXAMPLE: Wallasea Island Wild Coast project (UK)</a></div> </div> </div> <div class="clearfix text-formatted field field--name-field-literature-sources field--type-text-long field--label-above"> <div class="field__label">Literature sources</div> <div class="field__item"><h6>Heather Forbes, Kathryn Ball and Fiona McLay (2015): Natural Flood Management Handbook. Published by Scottish Environment Protection Agency (https://www.sepa.org.uk/media/163560/sepa-natural-flood-management-handbook1.pdf)</h6></div> </div> <div class="field field--name-field-measure-category field--type-entity-reference field--label-above"> <div class="field__label">Measure category</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/76" hreflang="en">Mitigation</a></div> </div> </div> Sun, 11 Sep 2016 19:51:14 +0000 giacomo.cazzola 87 at https://coastal-management.eu Riparian buffers https://coastal-management.eu/measure/riparian-buffers <span class="field field--name-title field--type-string field--label-hidden">Riparian buffers</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="https://coastal-management.eu/user/27" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">giacomo.cazzola</span></span> <span class="field field--name-created field--type-created field--label-hidden">Sun, 09/11/2016 - 21:40</span> <div class="field field--name-field-adressed-disks field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/53" hreflang="en">Riverine or slow rise floods</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/36" hreflang="en">Erosion</a></div> </div> <div class="field field--name-field-type-of-measure field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/58" hreflang="en">Natural flood, runoff, catchment management</a></div> </div> <div class="field field--name-field-type-of-coastal-defence-st field--type-entity-reference field--label-hidden field__item"><a href="https://coastal-management.eu/taxonomy/term/73" hreflang="en">Limited intervention</a></div> <div class="field field--name-field-colour field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/65" hreflang="en">Ecosystem based approach</a></div> </div> <div class="clearfix text-formatted field field--name-field-short-descr field--type-text-long field--label-hidden field__item"><p>Riparian buffers are vegetated, often forested, areas (“strips”) adjacent to streams, rivers, lakes and other waterways protecting aquatic environments from the impacts of surrounding land use (Enanga et al. 2010). Use of riparian buffers to maintain water quality in streams and rivers is considered to be a best forest and conservation management practice in many countries and is mandatory in some areas.</p></div> <div class="clearfix text-formatted field field--name-field-information-source field--type-text-long field--label-hidden field__item"><p><a href="http://web.unep.org/ecosystems/sites/default/files/uploads/resource/file/Green%20infrastructure%20Guide.pdf">Based on kindly provided information by UNEP's "Green Infrastructure Guide for Water Management: Ecosystem-based Management Approaches to Water-related Infrastructure Projects " (UNEP, 2014)</a></p></div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><h4>Benefits</h4> <p>Riparian buffers help to maintain water quality in waterways by protecting streams from non-point source pollution (e.g. from surrounding agricultural activities). Riparian vegetation cover prevents sediments, as well as such pollutants as nitrogen, phosphorus and others from entering water through biological (e.g. nutrient uptake by riparian vegetation) and physical-chemical (e.g. nutrient absorption for phosphorus which binds to clay particles and sediments) processes (Enanga et al. 2010).</p> <p>Vegetation and tree roots also stabilize banks and prevent erosion. During flood events, riparian vegetation slows down runoff by absorbing excess water, reduces peak flow and helps to mitigate potential flood damage downstream (Colgan et al. 2013). Such buffer strips also yield benefits in agricultural areas, both by retaining sediment and nutrients from entering the waterways, thereby preventing water pollution, and maintaining soil productivity on the fields (Schmidt and Batker 2012). Some studies show that riparian buffers can help to reduce the amount of sediment reaching the streams by as much as 80 per cent (Crétaz and Barten 2007).</p> <p>Trees also provide shade and reduce water temperature fluctuations, which is an important factor for the survival of many aquatic species. Shade provided by riparian vegetation also contributes to maintaining water quality, as high levels of light leads to increases in in-stream primary production, and can change the invertebrate species composition (Parkyn 2004). Increases in summer water temperatures can increase anoxia in stratified lakes, elevate the rate of phosphorus releases from lake and slow moving river sediments and cause algal blooms (Whitehead et al. 2009). Together with changes in actual water flows that affect riparian vegetation and water biota, the combined factors can impact on riparian food webs (Covich et al. 1999). A recent study in Denmark found that relatively short stretches (100–500 m) of riparian forest combat the negative effects of heating of stream water (Kristensen et al. 2013).</p></div> <div class="clearfix text-formatted field field--name-field-second-descrip field--type-text-long field--label-hidden field__item"><h4>Co-benefits</h4> <p>Depending on the extent and the type of vegetation in the riparian buffers, they can provide important biodiversity benefits. Vegetation provides biodiversity habitat for many species, that in some cases can be particularly beneficial for agricultural activities via insects and birds that facilitate pollination of the fields. The cover and shade also provide favourable conditions for birds and other animals that can take refuge in the buffer zones, and which use the riparian buffer zones as corridors for movement. This is important for pastoralist communities that often rest animals in riparian areas for watering, grazing and protection. Riparian vegetation, either designed or natural, is sometimes referred to as “shelterbelts” and offer shade and weather protection (due to cooling effects). They also reduce wind velocities, dust (including air pollutants) and erosion (Bird et al. 1992; Bird 1998; Heath et al. 1999).</p> <p>In addition, riparian buffers can offer aesthetic and recreation value to nearby communities (Schmidt and Batker 2012). Drought, however, can weaken the resilience of intact riparian vegetation and larger forest ecosystems to pests and disease (Anderson 2008). The falling leaves and debris in turn provide food for aquatic species (Parkyn 2004). Moreover, water systems containing too many dead leaves and stored organic matter can become hypoxic, with decreased pH and fairly high concentrations of tannin and lignin, making the water toxic to fish and other aquatic species (Gehrke et al. 1993; Bond et al. 2008).</p> <h4>Costs</h4> <p>Costs associated with establishment and conservation of riparian buffer strips include land acquisition and any associated foregone economic opportunity, and when necessary, the planting of buffer zones. Where riparian land is on private property, public investment may need to be made for land acquisition or economic incentives for private landowners to establish riparian buffers.</p></div> <div class="field field--name-field-further-readings field--type-link field--label-above"> <div class="field__label">Further Readings</div> <div class="field__items"> <div class="field__item"><a href="http://climate-adapt.eea.europa.eu/metadata/adaptation-options/establishment-and-restoration-of-riparian-buffer-s">Climat Adapt on riparian buffer</a></div> </div> </div> <div class="clearfix text-formatted field field--name-field-literature-sources field--type-text-long field--label-above"> <div class="field__label">Literature sources</div> <div class="field__item"><h5>Alexander, S. and McInnes, R. (2012). The benefits of wetland restoration. Ramsar Scientific and Technical Briefing Note No. 4. Ramsar Convention Secretariat, Gland, Switzerland.</h5> <h5>Anderson, J. ed. (2008). Climate change-induced water stress and its impact on natural and managed ecosystems. Study for the European Parliament’s Temporary Committee on Climate Change. Available from http://www.europarl.europa.eu/activities/committees/studies/download.do?file=19073.</h5> <h5>Bird, P.R. (1998). Tree windbreaks and shelter benefits to pastures in temperate grazing systems, Agroforestry Systems, vol. 41, 35-54.</h5> <h5>Bird, P.R., Bicknell, D., Bulman, P.A., Burke, S.J.A., Leys, J.F., Parker, J.N., van der Sommen, F.J. and Voller, P. (1992). The role of shelter in Australia for protecting soils, plants and livestock, Agroforestry Systems, vol. 18, pp. 59-86.</h5> <h5>Bond, N. R., Lake, P. S. and Arthington, A. H. (2008). The impacts of drought on freshwater ecosystems: an Australian perspective.  Hydrobiologia, vol. 600, pp. 3-16.</h5> <h5>Colgan, C.S., Yakovleff, D. and Merrill, S.B. (2013). An Assessment of the Economics of Natural and Built Infrastructure for Water Resources in Maine. (May).</h5> <h5>Covich, A.P., Palmer, M.A. and Crowl, T.A. (1999). The role of benthic invertebrate species in freshwater ecosystem, BioScience, vol. 49, pp. 119-127.</h5> <h5>De la Crétaz, A. and Barten, P. K. (2007). Land Use Effects on Streamflow and Water Quality in the Northeastern United States. CRC Press.</h5> <h5>Echavarria, M. (2002). Financing Watershed Conservation: The FONAG Water fund in Quito, Ecuador. In Selling Forest Environmental Services: Market-based Mechanisms for Conservation and Development, Pagiola, S., Bishop, J. and Landell-Mills, N., eds. London: Earthscan Publications.</h5> <h5>Enanga E.M., Shivoga W.A., Maina-Gichaba C., Creed I.F. (2010). Observing Changes in Riparian Buffer Strip Soil Properties Related to Land Use Activities in the River Njoro Watershed, Kenya, Water Air Soil Pollution, vol. 218, pp. 587–601.</h5> <h5>EPA (2012). United States Environmental Protection Agency, River Corridor and Wetland Restoration. Available from http://water.epa.gov/type/wetlands/restore/index.cfm.</h5> <h5>Forslund, A. et al. (2009). Securing Water for Ecosystems and Human Well-being: The Importance of Environmental Flows. Swedish Water House Report 24. SIWI. Available from http://www.unepdhi.org/~/media/Microsite_UNEPDHI/Publications/documents/unep_DHI/Environmental%20Flows%20Report%2024%20-low-res.ashx.</h5> <h5>Gehrke, P.C., Revell, M.B. and Philbey, A.W. (1993). Effects of river red gum, Eucalyptus camaldulensis, litter on golden perch, Macquaria ambigua, Journal of Fish Biology, vol. 43, pp. 265–279.</h5> <h5>Harding, J. S.,Claassen, K. and Evers, N. (2006). Can forest fragments reset physical and waterquality conditions in agricultural catchments and act as refugia for forest stream invertebrates?, Hydrobiologia, vol. 568, pp. 391-402.</h5> <h5>Heath, B.A., Maughan, J.A., Morrison, A.A., Eastwood, I.W., Drew, I.B. and Lofkin, M. (1999). The influence of wooded shelterbelts on the deposition of copper, lead and zinc at Shakerley Mere, Cheshire, England. The Science of the Total environment, vol. 235, No. 1-3, pp. 415-417. (September).</h5> <h5>Nilsson, C. and Renöfält, B.M. (2008). Linking flow regime and water quality in rivers: a challenge to adaptive catchment management, Ecology and Society, vol. 13, No. 2, p. 18.</h5> <h5>Russi, D., ten Brink, P., Farmer, A., Badura, T., Coates, D., Förster, J., Kumar, R. and Davidson, N. (2013). The Economics of Ecosystems and Biodiversity for Water and Wetlands. IEEP, London and Brussels; Ramsar Secretariat, Gland, Switzerland.</h5> <h5>Silva, J. P., Toland, J., Jones, W., Eldridge, J., Hudson, T., O’Hara, E. and Thévignot, C. (2010). LIFE building up Europe’s green infrastructure. Addressing connectivity and enhancing ecosystem functions, European Union.</h5> <h5>Schmidt, R. and Batker, D. (2012). Nature’s Value in the McKenzie Watershed: A Rapid Ecosystem Service Valuation, Earth Economics. (May).</h5> <h5>Parkyn S. (2004). Review of Riparian Buffer Zone Effectiveness, MAF Technical Paper No: 2004/05. (September).</h5> <h5>Whitehead, P.G., Wilby, R.L., Batterbee, R.W., Kernan, M. and Wade, A.J. (2009). A review of the potential impacts of climate change on surface water quality. Hydrological Sciences, vol. 54, No. 1, pp. 101-123.</h5></div> </div> <div class="field field--name-field-measure-category field--type-entity-reference field--label-above"> <div class="field__label">Measure category</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/76" hreflang="en">Mitigation</a></div> </div> </div> Sun, 11 Sep 2016 19:40:18 +0000 giacomo.cazzola 86 at https://coastal-management.eu Sea Dikes https://coastal-management.eu/measure/sea-dikes <span class="field field--name-title field--type-string field--label-hidden">Sea Dikes</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="https://coastal-management.eu/user/27" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">giacomo.cazzola</span></span> <span class="field field--name-created field--type-created field--label-hidden">Thu, 09/08/2016 - 16:28</span> <div class="field field--name-field-adressed-disks field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/35" hreflang="en">Estuarine floods</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/37" hreflang="en">Coastal floods or storm surges</a></div> </div> <div class="field field--name-field-type-of-measure field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/60" hreflang="en">Channel, Coastal and Floodplain Works</a></div> </div> <div class="field field--name-field-type-of-coastal-defence-st field--type-entity-reference field--label-hidden field__item"><a href="https://coastal-management.eu/taxonomy/term/73" hreflang="en">Limited intervention</a></div> <div class="field field--name-field-colour field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/67" hreflang="en">Grey infrastructure</a></div> </div> <div class="clearfix text-formatted field field--name-field-short-descr field--type-text-long field--label-hidden field__item"><p><span lang="EN-US" xml:lang="EN-US" xml:lang="EN-US">A sea dike is a manmade structure designed to protect low-lying areas from flooding from the sea or ocean. They typically are designed with several components including a sand core, a watertight outer protective layer, toe protection and a drainage channel. Sea dikes are intended to withstand and resist water and wave action. They are widely used in countries with low lying geographies such as Vietnam, Bangladesh, Thailand, the Netherlands and parts of the United States.</span></p></div> <div class="clearfix text-formatted field field--name-field-information-source field--type-text-long field--label-hidden field__item"><p>Based on kindly provided information by the <a href="http://www.climatetechwiki.org/content/sea-dikes">ClimateTechWiki </a> and the TNA Guidebook on '<a href="http://www.unep.org/pdf/TNAhandbook_CoastalErosionFlooding.pdf">Technologies for Climate Change Adaptation'</a> by Matthew M. Linham & Robert J. Nicholls</p></div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>The construction of a dike has three functional parts – a submerged base, the middle area that experiences constant loading from waves, the upward middle zone that can experience wave pressure during storms and finally the above area or ‘dike crest’ that mainly absolves wave run-up. A number of zones can be distinguished on the seaward slope of a sea dike. </p> <h4>Advantages of the technology</h4> <p>Dikes are hard measures that provide a high-degree of protection against flooding. Compared to other hard measures that require civil engineering, they are comparatively less expense. Dikes provide a high degree of protection against flooding in low-lying coastal areas. </p> <p>Dikes designed with a slope are more effective than vertical dikes. The sloped dike forces the wave to break when the water becomes shallow, and therefore reduces the energy of the wave. Dissipation of wave energy or wave loadings reduces the damage that the wave could cause in relation to erosion of the shoreline. </p> <p>When compared to vertical structures, dikes also have reduced toe scour.  This is because the wave downrush is directed away from the base of the structure. This is beneficial for structural stability and helps to reduce the risk of undermining.</p> <h4>Disadvantages of the technology</h4> <p>As a hard measure, dikes are usually a big construction undertaking and require large columes of building materials including sand, clay and asphalt. While they are comparatively less costly than some other hard measures, the undertaking of such extensive construction is still expensive and require continual maintenance costs.</p> <p>Sloped dikes described above are particularly important for dissipating wave energy, but they also require more land on which to be constructed. This increases their cost and the overall intrusion of a built structure on a natural environment. Moreover, the construction of dikes often prevents the areas from being used for other activities such as tourism creating conflicts of interest and competition for land. One option is to extend dikes seaward, rather than landward, however this significantly increases the costs.</p> <p>Permanent structures involving significant construction have a direct impact on the natural dynamic processes of a coastline. They can create new problems related to natural responses to sea level changes, beach and dune interaction and sediment input from coastal erosion. Interfering and preventing natural coastline dynamics can create problems for the area in question as well as the adjacent ecosystems.</p> <h4>Financial requirements and costs</h4> <p>In a country comparative study by Hillen et al. (2010), the costs of building a dike are compared. As may be expected, the costs in some developing countries are significantly less than in the United States and the Netherlands. Moreover, there are considerable discrepancies in costs dependent on whether the dike is built in an urban or rural area. In the United States, the cost of dikes are estimated to range significantly from US.09 to 29.2 million per metre rise in height per km in length. In Vietnam, dike construction costs were shown to vary from US$0.9 to 1.6 million per metre rise in height, per km length (Hillen et al., 2010). </p> <p>Other variables that determine cost are summarized by Hillen et al (2010).</p> <ul> <li>Land availability and cost.  As shown in Figure 4.13, dike construction needs significant land input.  Accurate cost studies often draw a distinction between rural and urban construction costs to reflect differential land values</li> <li>Selected dike design and in-built margin for safety.  This can affect the volume of the structure and the required materials</li> <li>Anticipated wave loadings; higher wave loadings require more robust and expensive structures.  Wave loading is affected by wave breaker types, cleanness of the breaking wave, seabed shape and individual storm characteristics such as storm duration, wind strength and storm orientation in relation to the structure</li> <li>Single or multi stage construction; aggregate costs are lower for single stage construction</li> <li>Proximity to and availability of raw construction materials</li> <li>Availability and cost of human resources including expertise</li> </ul> <h4>Institutional and organisational requirements </h4> <p>Dikes vary in scale and design. Construction of sea dikes is possible at a local scale, however, in such cases it is important that the science and technology behind the decision to construct a dike is sound. In some cases, poor dike design brings about lower levels of protection and wasted funds. Dikes that are built ‘ad hoc’ dike designs often pay less attention to planning, water heights, wave heights and do not accurately meet the needs of an actual extreme event mainly because information about the type and scale of the event are difficult to predict. Dikes built ad-hoc generally provide less protection.</p> <p>Extreme caution should be exercised if ad-hoc, community implementation of sea dikes goes ahead.  Because dikes are often designed to protect extensive areas of low-lying land, catastrophic failure caused by poor design is likely to be associated with a threat to the lives of significant numbers of people.</p> <p>The most effective dikes are those designed in accordance with good quality, long-term environmental data, such as wave height and extreme sea level information.</p></div> <div class="clearfix text-formatted field field--name-field-second-descrip field--type-text-long field--label-hidden field__item"><h4>Barriers to implementation </h4> <p>A major barrier to dike construction is that building requires significant coastal land. The use of coastal land for dikes raises several problems that include conflicts of interest between users, especially since dikes usually reduce accessibility and use by communities of the shore. They also require land which may be desired for other purposes or privately owned.</p> <p>One of the main barriers to the building of an effective dike which accounts for local conditions is the availability of long-term datasets. Collecting such data can be expensive especially as an up-front cost, however careful planning typically makes dikes more effective. </p> <h4>Opportunities for implementation </h4> <p>Dikes have become essential to areas below sea level that have high value coastal land that cannot be surrendered to the sea (i.e. urban developments (e.g. Amsterdam)). In such cases, dikes designed correctly are extremely effective in providing high levels of protection against coastal flooding. This can enable significant development to take place behind them, even if land is low-lying.  This is demonstrated by Schiphol Airport, Amsterdam, in the Netherlands – the area is enclosed by dikes but lies 4.5 m below sea level (Pilarczyk, 2000). </p> <p>Dikes are a tried-and-tested method of coastal protection.  Although specialised dikes, designed with local conditions in mind pose the most effective defences, it is also possible to implement more generic or lower quality designs at a lower cost. </p> <p>Dikes can also be constructed to compliment other erosion and flood protection works such as beach nourishment and managed realignment. This has the potential to address the negative impacts associated with the technology and also means the benefits associated with each technology can be realised.</p></div> <div class="field field--name-field-relevant-case-studies-and- field--type-entity-reference field--label-above"> <div class="field__label">Relevant case studies and examples</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/measure/example-public-participation-dyke-construction-timmendorfer-strand-ger" hreflang="en">EXAMPLE: Public participation in dyke construction, Timmendorfer Strand (GER)</a></div> </div> </div> <div class="clearfix text-formatted field field--name-field-literature-sources field--type-text-long field--label-above"> <div class="field__label">Literature sources</div> <div class="field__item"><h5><em>Main source: </em> Matthew M. Linham & Robert J. Nicholls (2010):<em> </em>TNA Guidebook on '<a href="http://www.unep.org/pdf/TNAhandbook_CoastalErosionFlooding.pdf">Technologies for Climate Change Adaptation'</a> UNEP , 166p.</h5> <h6>Hillen, M.M., Jonkman, S.N., Kanning, W., Kok, M., Geldenhuys, M., Vrijling, J.K. and Stive, M.J.F. (2010) <a href="http://repository.tudelft.nl/islandora/object/uuid:604825d4-f218-40fc-b3b5-5f4280b2338d?collection=research">Coastal Defence Cost Estimates</a>. Case Study of the Netherlands, New Orleans and Vietnam. The Netherlands: TU Delft.</h6> <h6>Pilarczyk, K.W. (2000) Design of dikes and revetments – Dutch practice in Herbich, J.B. (ed.).  Handbook of Coastal Engineering.  New York: McGraw-Hill, Chapter 3.</h6></div> </div> <div class="field field--name-field-measure-category field--type-entity-reference field--label-above"> <div class="field__label">Measure category</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/75" hreflang="en">Prevention</a></div> </div> </div> Thu, 08 Sep 2016 14:28:15 +0000 giacomo.cazzola 76 at https://coastal-management.eu Rivers dredging https://coastal-management.eu/measure/rivers-dredging <span class="field field--name-title field--type-string field--label-hidden">Rivers dredging</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="https://coastal-management.eu/user/27" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">giacomo.cazzola</span></span> <span class="field field--name-created field--type-created field--label-hidden">Thu, 09/08/2016 - 15:17</span> <div class="field field--name-field-adressed-disks field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/53" hreflang="en">Riverine or slow rise floods</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/35" hreflang="en">Estuarine floods</a></div> </div> <div class="field field--name-field-type-of-measure field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/60" hreflang="en">Channel, Coastal and Floodplain Works</a></div> </div> <div class="field field--name-field-type-of-coastal-defence-st field--type-entity-reference field--label-hidden field__item"><a href="https://coastal-management.eu/taxonomy/term/73" hreflang="en">Limited intervention</a></div> <div class="field field--name-field-colour field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/66" hreflang="en">Combined approach (grey + green)</a></div> </div> <div class="clearfix text-formatted field field--name-field-short-descr field--type-text-long field--label-hidden field__item"><p>Dredging is the general term used for the excavation of material below water level either as a maintenance activity or as part of channel enlargement works. The main purpose of dredging is either to maintain the navigation depth or the flood capacity, or sometimes both.</p></div> <div class="clearfix text-formatted field field--name-field-information-source field--type-text-long field--label-hidden field__item"><p>Based on "<a href="http://repository.tudelft.nl/islandora/object/uuid:b10ee43e-def9-4e02-8571-a495bbe1d361?collection=research#">A T Pepper, C E Rickard (2009): 8 Works in the river channel. 36p. In: UK Environmental Agency (2009): Fluvial Design Guide </a>(Contains public sector information licensed under the Open Government Licence v3.0.)"</p></div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Dredging is an expensive operation and can have severe environmental drawbacks. The expense is not only in the dredging operation itself but also the disposal of the dredged material, which may be contaminated and require disposal to a licensed landfill, with associated transportation costs. Dredging should therefore be avoided wherever possible, especially since it is almost never a ‘one off’ operation.</p> <p>Environmental damage can be reduced by carrying out the dredging in the appropriate season, for example to avoid polluting fish spawning grounds with fine sediment disturbed by the dredging process. Avoidance of the summer season when boating and other river-based activities are at their peak is also advisable, but this may leave a narrow window for the dredging operations when other restrictions are taken into account.</p> <p>The environmental impacts can also be minimised by choosing the right plant and equipment for the dredging. Mechanical removal of material from the bed (for example, using a dragline or a grab) is likely to create the most disturbance and hence sediment pollution, although measures can be taken to reduce this impact.</p> <p>The sediment derived from the dredging can be re-used for DRR measures. How this can be achieved, can be read <a href="http://deltaproof.stowa.nl/Publicaties/deltafact/The_beneficial_re_use_of_dredged_material?subject="><strong>here</strong></a>.</p></div> <div class="field field--name-field-further-readings field--type-link field--label-above"> <div class="field__label">Further Readings</div> <div class="field__items"> <div class="field__item"><a href="http://deltaproof.stowa.nl/Publicaties/deltafact/The_beneficial_re_use_of_dredged_material?subject=9">The beneficial re-use of dredged material</a></div> </div> </div> <div class="field field--name-field-scale field--type-entity-reference field--label-above"> <div class="field__label">Scale</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/70" hreflang="en">Local</a></div> </div> </div> <div class="field field--name-field-measure-category field--type-entity-reference field--label-above"> <div class="field__label">Measure category</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/75" hreflang="en">Prevention</a></div> </div> </div> Thu, 08 Sep 2016 13:17:52 +0000 giacomo.cazzola 70 at https://coastal-management.eu Drainage system management https://coastal-management.eu/measure/drainage-system-management <span class="field field--name-title field--type-string field--label-hidden">Drainage system management</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="https://coastal-management.eu/user/27" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">giacomo.cazzola</span></span> <span class="field field--name-created field--type-created field--label-hidden">Tue, 09/06/2016 - 16:39</span> <div class="field field--name-field-adressed-disks field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/54" hreflang="en">Urban floods</a></div> </div> <div class="field field--name-field-type-of-measure field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/57" hreflang="en">Reduction</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/61" hreflang="en">Surface Water Management</a></div> </div> <div class="field field--name-field-type-of-coastal-defence-st field--type-entity-reference field--label-hidden field__item"><a href="https://coastal-management.eu/taxonomy/term/73" hreflang="en">Limited intervention</a></div> <div class="field field--name-field-colour field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/67" hreflang="en">Grey infrastructure</a></div> </div> <div class="clearfix text-formatted field field--name-field-short-descr field--type-text-long field--label-hidden field__item"><p>Urban drainage systems need to be able to deal with both wastewater and stormwater whilst minimizing problems to human life and the environment, including flooding. Urbanization has a significant effect on the impact of drainage flows on the environment: for example, where rain falls on impermeable artificial surfaces and is drained by a system of pipes, it passes much more rapidly to the receiving water body than it would have done when the catchment was in a natural state. This causes a more rapid build-up of flows and higher peaks, increasing the risk of flooding (and pollution) in the receiving water. Many urban drainage systems simply move a local flooding problem to another location and may increase the problem. In many developed counties there is a move away from piped systems, towards more natural systems for draining stormwater.</p></div> <div class="clearfix text-formatted field field--name-field-information-source field--type-text-long field--label-hidden field__item"><p>Based on: <a href="https://openknowledge.worldbank.org/handle/10986/2241"><em>Jha, Abhas K., Robin Bloch, and Jessica Lamond. Cities and Flooding: A Guide to Integrated Urban Flood Risk Management for the 21st Century. World Bank Publications, 2012.</em></a></p></div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Where the drainage system of an urban area is piped, by a ‘sewer system’, there are two approaches in use: ‘combined’ or ‘separate’.</p> <p>The older parts of many cities (New York being an example) are drained using the combined system, whereby wastewater and stormwater are mixed and are carried together. The system takes the combined flow to the point of discharge into the natural water system, commonly via a wastewater treatment plant that discharges treated effluent. During heavy rainfall events, the stormwater flow will greatly dominate the wastewater flow in terms of volume, but it is hardly ever viable to provide sufficient capacity throughout the system for stormwater resulting from heavy rainfall, as the system would operate at a small fraction of its capacity during dry weather. Instead, structures are included in the system to permit overflow to a nearby watercourse. During significant rainfall events a significant volume of the flow is likely to overflow, rather than to continue to the wastewater treatment plant. As the overflowed water is generally a dilute mixture of wastewater and stormwater, these structures are designed hydraulically to prevent larger, visually offensive solids from being discharged to the river. However, the inescapable fact is that combined sewer overflows inevitably cause some pollution (Butler and Davies 2011).</p> <p>In the urban areas served by a combined system, capacity is similarly exceeded by extreme stormwater flows. Under these circumstances, the ‘surcharging’ of the system may cause flooding of the urban surface and, as the flood water will include wastewater, there are associated pollution and health implications.</p> <p>In a separate system, wastewater and stormwater are drained by separate pipes, often constructed in parallel. Wastewater is carried to the wastewater treatment plant, whereas stormwater is usually discharged direct to the nearest watercourse. The problem of combined sewer overflows is thereby avoided, but there are still challenges: stormwater discharge is usually untreated, and this may cause pollution. Stormwater may enter the wastewater pipe  either through mistaken or unauthorized connections; there may also be infiltration of groundwater at pipe imperfections. Because of the relative proportions of wastewater and stormwater during heavy rainfall, these additional inputs may significantly reduce the capacity of the pipe for the wastewater it was designed to carry.</p> <p>In urban areas without conventional piped sewer systems, disposal of excreta and wastewater is likely to be localized, though in some cases simplified (shallow and small diameter) pipes are used. Stormwater is most likely to be carried by open drains, typically unlined channels along the side of the street. Better constructed channels may be lined with stone or concrete, and may be integrated into the urban landscape. Open drains are far cheaper to construct than stormwater sewers, and although they can easily become blocked by debris or refuse from the surface, such blockages are more easily monitored and removed than in piped systems.</p> <p>Maintenance is vital, not only to remove obvious obstructions, but also cleaning out deposited sediment, and then disposing of the material so that it does not go back into the drain. In heavy rain, the capacity of an open urban drainage channel may quickly be exceeded; in a well planned system, overflow should be to a specified ‘<a href="http://coastal-management.eu/types-flood-storage">major system</a>’ such as a road which can act as a drainage channel.</p> <p>Where there is no adequate system for disposal of wastewater, there is a high likelihood that open drains will be contaminated by foul sewage. This could come from contributions from areas without sewers, or from discharge from simplified sewerage which does not lead to an adequate treatment facility. Open drains may also be misused for the disposal of domestic solid waste. Where the quality of stormwater carried in open drains is an issue for these reasons, there may be limited opportunities for using semi-natural systems of urban drainage that rely on the storage or infiltration of stormwater because of public health issues.</p></div> <div class="clearfix text-formatted field field--name-field-literature-sources field--type-text-long field--label-above"> <div class="field__label">Literature sources</div> <div class="field__item"><p>Butler D. and Davies J.W. 2011 Urban Drainage, 3rd edition. UK: Spon Press.</p></div> </div> <div class="field field--name-field-scale field--type-entity-reference field--label-above"> <div class="field__label">Scale</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/71" hreflang="en">Individual - private</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/70" hreflang="en">Local</a></div> </div> </div> <div class="field field--name-field-measure-category field--type-entity-reference field--label-above"> <div class="field__label">Measure category</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/76" hreflang="en">Mitigation</a></div> </div> </div> Tue, 06 Sep 2016 14:39:06 +0000 giacomo.cazzola 63 at https://coastal-management.eu Exposed elements elevation https://coastal-management.eu/measure/exposed-elements-elevation <span class="field field--name-title field--type-string field--label-hidden">Exposed elements elevation</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="https://coastal-management.eu/user/27" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">giacomo.cazzola</span></span> <span class="field field--name-created field--type-created field--label-hidden">Tue, 09/06/2016 - 11:53</span> <div class="field field--name-field-adressed-disks field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/53" hreflang="en">Riverine or slow rise floods</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/52" hreflang="en">Flash floods</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/35" hreflang="en">Estuarine floods</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/37" hreflang="en">Coastal floods or storm surges</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/54" hreflang="en">Urban floods</a></div> </div> <div class="field field--name-field-type-of-measure field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/56" hreflang="en">Removal or relocation</a></div> </div> <div class="field field--name-field-type-of-coastal-defence-st field--type-entity-reference field--label-hidden field__item"><a href="https://coastal-management.eu/taxonomy/term/73" hreflang="en">Limited intervention</a></div> <div class="field field--name-field-colour field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/67" hreflang="en">Grey infrastructure</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/68" hreflang="en">Non-structural measure</a></div> </div> <div class="clearfix text-formatted field field--name-field-short-descr field--type-text-long field--label-hidden field__item"><p>'Elevation of buildings' and ' Land raising' are two separated measures with the aim to elevate exposed elements.</p></div> <div class="clearfix text-formatted field field--name-field-information-source field--type-text-long field--label-hidden field__item"><p><a href="http://coastal-management.eu/measure/wet-proofing-sealable-buildings">Based on kindly provided information on the Flood Management Tools Series by the Associated Programme on Flood Management</a></p></div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><h3>Elevation of building</h3> <p>In order to protect an existing building from flooding, elevation of the building is one retrofitting method. The two major types of elevating living spaces above the expected flood level are:</p> <p>1) lifting up a building on a new or extended foundation; and (2) extending a building upward by elevating the existing floor or adding a new upper story utilizing an existing foundation (FEMA, 2009). The first method separates the building from its foundation, raises it on a hydraulic jack, and constructs a new or extended foundation below it. The new and extended foundation can be continuous walls, or separate piers, posts, columns or piles and can be exposed to flooding. The second method removes the roof, extends the building walls, and constructs a raised floor. The abandoned lower area can then be used for parking, building access or storage.</p> <p>The height of elevation is determined by the expected flood level, that is, the lowest floor of the living space must be above the flood level, including freeboard. As with a <a href="http://coastal-management.eu/measure/wet-proofing-sealable-buildings">wetproofing </a>measure, the foundation of the elevated building must be able to withstand hydrostatic pressure, hydrodynamic pressure, debris impact, and erosion by flooding. Design experts should be consulted for these elevation projects to evaluate whether the existing foundations can support an increased load to the building. If the project site is subject to high winds, earthquakes, or other hazards, such horizontal and vertical forces must be also considered. More detailed elevation techniques are explained in “Homeowner’s Guide to Retrofitting” (FEMA, 2009).</p> <p>In response to Hurricane Katrina, FEMA evaluated building damage from the hurricane and provided recommendations on building structures in “Summary Report on Building Performance - Hurricane Katrina 2005” (FEMA, 2006). The assessment found that the buildings that survived the hurricane event have some elements in common, such as high first floor elevations, a well. embedded deep pile foundation, and structurally connected foundation and building frame.</p></div> <div class="clearfix text-formatted field field--name-field-second-descrip field--type-text-long field--label-hidden field__item"><h3>Land raising</h3> <p>In the United States, National Flood Insurance Program (NFIP) regulations only allow landfill, encroachment, and other developments within a floodway if they are proven through standard hydrologic and hydraulic analyses not to increase flood levels in the community during the base flood discharge (FEMA, 1993). New developments and significant improvements are, in general, required to not cause negative impacts, not only to increasing flood heights, but also in creating additional threats to public safety, inducing extra public expenditure, creating nuisances, or conflicting with existing local regulations.</p> <p>Land raising (or placement of fill) requires an understanding of local site conditions, soil characteristics, methods of placing and compacting the land, etc. (FEMA, 2001). The permeability of soils affects water infiltration on the site, which in turn influences the safety of the foundations or basement structure. The higher the lowest floor of building is elevated in comparison with the expected flood level, the safer the building becomes. If the elevation of the building is not high enough compared to the expected flood level or if it includes a basement below the flood level, additional measures of dryproofing and elevating the building should also be considered.</p> <p>In order to combat hydrostatic force and buoyancy force, appropriate buffer zones   around a building should be installed with a setback distance from the edge of the flood hazard area. The fill soil should be homogeneous and of a low permeability. A drainage system installed around the building foundations with a sump pump can lower the level of seepage and make the structure safer. FEMA provides the method of calculating such seepage flow.</p> <p>Raising houses, tube wells, and latrines above the expected flood level is an effective flood mitigation measure in developing countries. In India, there are examples of raised platforms in flood shelters constructed for local people and their cattle (WMO, 2005). In rural Bangladesh, homestead plinths of local people were raised to reduce vulnerability to flood disaster (Practical Action Bangladesh, 2010). In order to reduce water-borne diseases, especially during periods of inundation, tube-well platforms were raised above the highest ever recorded flood level with freeboard.</p> <p>Major sanitation problems in flood.prone areas of developing countries are surface water contamination and difficult access to latrines during floods (Kazi and Rahman, 1999). Because overflow of a pit latrine poses serious health and environmental risks, the top of the latrine    is extended above the expected flood level to avoid flood water intrusion into the pit which would expand its volume. One effective measure of preventing groundwater contamination by latrines is to surround the pit latrine with a sand filter and make the bottom of the pit impermeable. These measures are very simple and easily implemented by local people; however raising awareness about sanitary conditions and motivating people is the key to success of these projects.</p></div> <div class="field field--name-field-relevant-case-studies-and- field--type-entity-reference field--label-above"> <div class="field__label">Relevant case studies and examples</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/measure/example-concept-flood-proof-mooring-marina-ger" hreflang="en">EXAMPLE: Concept of „flood proof mooring“ in a Marina (GER)</a></div> <div class="field__item"><a href="https://coastal-management.eu/measure/example-floating-roads-hedel-nl" hreflang="en">EXAMPLE: Floating roads, Hedel (NL)</a></div> </div> </div> <div class="field field--name-field-further-readings field--type-link field--label-above"> <div class="field__label">Further Readings</div> <div class="field__items"> <div class="field__item"><a href="http://climate-adapt.eea.europa.eu/metadata/adaptation-options/floating-or-elevated-roads">ClimateAdapt on floating and elevated roads</a></div> </div> </div> <div class="clearfix text-formatted field field--name-field-literature-sources field--type-text-long field--label-above"> <div class="field__label">Literature sources</div> <div class="field__item"><h5>FEMA (Federal Emergency Management Agency), 1993b: Non-Residential Floodproofing - Requirements and Certification for Buildings Located in Special Flood Hazard Areas in accordance with the  National Flood Insurance Program. FIA.TB.3. www.fema.gov/library/viewRecord.do?id=1716</h5> <h5>FEMA (Federal Emergency Management Agency), 2001: Ensuring That Structures Built on Fill In or Near Special Flood Hazard Areas Are Reasonably Safe From Flooding in accordance with the National Flood Insurance Program. FIA.TB.10. www.fema.gov/library/viewRecord.do?id=1723</h5> <h5>FEMA (Federal Emergency Management Agency), 2006: Summary Report on Building Performance - Hurricane Katrina 2005. FEMA 548. www.fema.gov/library/viewRecord.do?id=1455</h5> <h5>FEMA (Federal Emergency Management Agency), 2009: Homeowner’s Guide to Retrofitting - Six Ways to Protect Your Home From Flooding. FEMA P.312, Second Edition. www.fema.gov/library/viewRecord.do?id=1420</h5> <h5>Kazi, N.M. and M. Rahman, 1999: Sanitation strategies for flood-prone areas. 25th WEDC Conference Integrated Developement for Water Supply and Sanitation , Addis Ababa. www.perusan.org/sysnet/publico/biblioteca/experiencias/saneamientozonasinundables/Flood%20latrine%20Brief%20Bangladesh.pdf</h5> <h5>Practical Action Bangladesh, 2010: Elements of disaster resilience: lessons from Bangladesh. Mainstreaming Livelihood-Centred Approaches to Disaster Management Project. practicalaction.org/disaster.management.bangladesh</h5> <h5>WMO (World Meteorological Organization), 2005: Manual on Community Approach to Flood Management in India. Associated Programme on Flood Management. www.apfm.info/pdf/pilot_projects/manual_india.pdf</h5></div> </div> <div class="field field--name-field-scale field--type-entity-reference field--label-above"> <div class="field__label">Scale</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/71" hreflang="en">Individual - private</a></div> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/70" hreflang="en">Local</a></div> </div> </div> <div class="field field--name-field-measure-category field--type-entity-reference field--label-above"> <div class="field__label">Measure category</div> <div class="field__items"> <div class="field__item"><a href="https://coastal-management.eu/taxonomy/term/76" hreflang="en">Mitigation</a></div> </div> </div> Tue, 06 Sep 2016 09:53:01 +0000 giacomo.cazzola 61 at https://coastal-management.eu