| 1. |
- Almström, Björn, et al.
(författare)
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Experiences of nature-based solutions for mitigating ship-induced erosion in confined coastal waters
- 2022
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Ingår i: Ecological Engineering. - : Elsevier BV. - 0925-8574. ; 180
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Tidskriftsartikel (refereegranskat)abstract
- Hydrodynamic forces from ships operating in sheltered, confined fairways can result in increased wave impact and sediment transport leading to loss of land and habitats. Nature-based solutions (NBS) offer the potential to mitigate ship-induced erosion and increase biodiversity and ecosystem services. The aim of this study is to evaluate the performance of NBS in a sheltered, confined fairway located in a cold, temperate region. The case study presents the results of a 2.5-year study of the morphologic response at two sites where NBS was implemented to mitigate bluff erosion and at one site where NBS was implemented to mitigate the retreat of a reed belt. Moreover, a qualitative assessment was made of the vegetation development at the sites. The results showed that fine sediments with planted vegetation could not withstand the hydrodynamic forces induced by the ships. However, by adding sills as stabilizing structures, the forces were sufficiently attenuated for the vegetation to establish. The vegetation, which reduced the ship-generated waves and currents, was especially important during high water-level events when the energy dissipation by the sill decreased. Moreover, a small-scale nourishment was successfully applied to mitigate bluff erosion without negatively affecting sediment supply to an adjacent sandy beach. This study demonstrates that NBS can be implemented to retain erodible sediment and favour vegetation growth in fairways experiencing primary and secondary waves produced by large, ocean-going ships.
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| 2. |
- Almström, Björn, et al.
(författare)
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Protecting intra-coastal fairways from ship waves using living shorelines techniques : A full scale experiment
- 2023
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Ingår i: Coastal Sediments 2023. - : WORLD SCIENTIFIC. - 9789811279898 ; , s. 2008-2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This study evaluates the effectiveness of applying living shoreline techniques for protecting reed belts and eroding bluffs in an intra-coastal fairway with intense traffic by ocean-going vessels. The re-establishment of the reed belt can be explained by the dissipation of the hydrodynamic forces by the sill structure. There is a negative relationship between vegetation growth and wave exposure due to washout from the rhizome layer and destabilization of the reed belt fringe by excessive wave forces. A stabilizing structure in front of vegetation may reduce the washout of seeds and promote the establishment and survival of sprouts. The stabilization of the bluff can be explained by that the protective measure reducing waves attacking the bluff base. Waves attacking the bluff base are one of the dominant processes for bluff erosion. In this study, the wave forces were reduced by the sill and the vegetation on the foreshore, in combination with elevated the bluff base due to the foreshore. After reinforcing the sills in September 2019 there has been no need for maintenance of the protective measures. The results after a four-year study period indicate reed growth can be promoted by installing a sill parallel to the shore and that eroding bluffs can be stabilized by creating a vegetated foreshore in front of the bluff combined with a shore parallel sill. This study showcases the potential of using living shoreline techniques in fairways exposed to intense ship traffic from larger vessels to promote reed growth and reduce bluff erosion.
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| 3. |
- Andersson-Sköld, Yvonne, 1957-, et al.
(författare)
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Ramverk för att prioritera och bedöma nyttan av klimatanpassningsåtgärder
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Klimatförändringarna är idag påtagliga och även om vi snabbt får ner utsläppen av växthusgaser kommer fler, mer omfattande och mer kostsamma klimatrelaterade händelser att inträffa alltmer ofta. Kostnaderna inom den svenska transportsektorn för klimatrelaterade händelser som skadar gator, vägar, spår-/järnväg, med flera sårbara delar av infrastrukturen är stora redan idag och förväntas öka. Översvämningar, bränder och skador till följd av väderrelaterade händelser på anläggningar resulterar bland annat i minskad framkomlighet och en ökad risk för olyckor. För att upprätthålla transportsystemets funktion är det därför viktigt att vi vidtar riskreducerande åtgärder för att minska sannolikheten och omfattningen av negativa konsekvenser av både dagens klimat- och väderrelaterade händelser men framför allt för att hantera framtida klimatrelaterade händelser. Det är nödvändigt att säkerställa transportsystemets funktion vid extrema väderhändelser, och under perioder av långvarig nederbörd, långvariga värmeböljor och förändrade nederbördsmönster. Det gäller också att redan idag möjliggöra anpassningsåtgärder för att hantera långsiktiga förändringar som höjd havsvattennivå och grundvattennivåer, som påverkar infrastrukturens framkomlighet och livslängd.I denna rapport presenteras sammanfattande resultat och en sammanfattning av hur ett ramverk för att utvärdera klimatrelaterade effektsamband har använts. Med effektsamband avses att identifiera, bedöma och värdera klimatrelaterade risker och riskreducerande åtgärder. I denna rapport är fokus på att identifiera, bedöma och utvärdera effektiviteten av klimatrelaterade åtgärder. Resultatet av det framtagna ramverket kan användas för att analysera riskreducerande åtgärders effekter, det vill säga för att bedöma om det är relevant att genomföra en åtgärd, när i tiden den bör genomföras samt för att bedöma vilken åtgärd som är mest relevant att genomföra. De risker som beaktas genom fallstudier innefattar brandrisk, olycksrisk på gator och vägar på grund av nollgenomgångar eller värme, översvämning, erosion och skred och påverkan på vägkonstruktionen (spårbildning, bärighet och utmattning), solkurvor och risker vid kraftiga vindar. Testerna har innefattat faro- och riskidentifiering, riskanalys, identifiering och utvärdering av möjliga åtgärder. Exempel på fallstudier är Gävleregnet 2021, ett skyfall i Kungsbacka kommun 2019, erosionsrelaterade förändringar under lång tid vid Österdalälven och beräkningar av påverkan av temperatur, fuktighet och förändringar i tjälförändringsmönster på vägkonstruktionen vid E10 vid Svappavaara. I en av de fallstudier som sammanfattas i rapporten redovisas även en monetär värdering och känslighetsanalys. Ramverket har också legat till grund för en diskussion avseende klimatrelaterade risker kopplade till elförsörjning.
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| 4. |
- Dahlberg, Anna-Karin, et al.
(författare)
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Dispersal of persistent organic pollutants from fiber-contaminated sediments : biotic and abiotic pathways
- 2021
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Ingår i: Journal of Soils and Sediments. - : Springer Science and Business Media LLC. - 1439-0108 .- 1614-7480. ; 21:4, s. 1852-1865
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Tidskriftsartikel (refereegranskat)abstract
- PurposeNumerous sites contaminated with fiber emissions from pulp and paper industries are found in coastal areas of the Baltic Sea, but there is limited knowledge about the magnitude of dispersal of persistent organic pollutants (POPs) from these anthropogenic, organic-rich sediments called fiberbanks. The aim of this study was to quantify and compare different POP dispersal pathways from such fiberbanks. Dispersal mechanisms studied included abiotic and biotic routes (dissolved in water, particle-bound, and bioaccumulation).Materials and methodsContaminated fibrous sediments located in Ångermanälven River estuary in north-eastern Sweden were studied in sediment types representing different fiber content (i.e., fiberbanks, fiber-rich sediments, and less fiber impacted sediments). Sediment-to-water fluxes of dissolved contaminants (polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and dichlorodiphenyltrichloroethane (DDT)) were measured in situ using benthic flux chambers. Particle resuspension was measured by sampling bottom water, before and after disturbing the sediment surface. Benthic biota was collected to determine the body burden of contaminants and to determine biota-pore water accumulation factors (BAFPW) and biota-sediment accumulation factors (BSAFs). In addition, concentrations of dissolved POPs in the water column were measured in field using passive samplers. Instrumental analysis was performed using gas chromatography coupled to a triple quadrupole mass spectrometer (GC-MS/MS).Results and discussionThe flux of dissolved Σ20PCBs was approximately two times higher from one of the investigated fiberbanks (3.4 ng m− 2 day− 1) compared to the other. The average particle burden of PCBs was also higher at this fiberbank after artificial disturbance (15 ng g−1 particle), which indicates that larger amounts of contaminants are likely to disperse via particle resuspension from this site compared to the other fiberbank (4.8 ng g− 1 particle). The difference might be associated with a layer of recently settled minerogenic material that covers one of the fiberbanks, which probably functions as a protective barrier. The lack of benthic biota implies that contaminant release by bioturbation is negligible in the studied fiberbanks. However, benthic biota from fiber-rich sediment showed bioaccumulation and biomagnification of contaminants.ConclusionsThe importance of diffusive flux from fiberbanks under undisturbed conditions became apparent when the different dispersal pathways were quantified. However, no dispersal pathway could be judged as irrelevant, since even under undisturbed conditions, advective particle transport was significant. Additionally, the uptake by biota and trophic transfer can be considerable. Quantification of dispersal routes and understanding of the relative importance of various pathways is critical for proper risk assessment and management of contaminated sediments.
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| 5. |
- Göransson, Gunnel, et al.
(författare)
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Opportunities for planned retreat and flexible land use in Sweden : Local, regional and national governance perspectives
- 2023
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Ingår i: Climate Risk Management. - : Elsevier. - 2212-0963. ; 41
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Tidskriftsartikel (refereegranskat)abstract
- As the sea level rises and the frequency of intense rains increase, so does the need for climate adaptation. Planning for a successive development of society away from current and future flood prone areas to give room for water is not seen as an alternative in Sweden today, although it could be a strategy that creates long-term security. In this study, we investigated Swedish public authorities' perceptions of planned retreat and flexible land use. This was done through an online survey and interviews directed to officials directly involved in climate adaptation work, at municipalities, County Administration Boards (CABs), Regions, national authorities (NAs), and industry organizations (IOs). The responses were analyzed through the lens of a windows of opportunity approach. The study indicates that the extent to which climate scenarios are used and how far into the future the planning horizon extends in the practical work, varies between governance level which also have impact on the perspectives on planned retreat. The openness for planned retreat and flexible strategies seemed to differ slightly between governance levels in an ascending scale from regions, IOs / NAs, municipalities, to CABs. The survey has generated insights from a large number of respondents at different governance levels sharing their perceptions of retreat and adaptation in Sweden as a main contribution of this work.Difficulties to deal with uncertainties in climate scenarios and considering long-term perspectives were identified as some reasons that close the window for planned retreat. Enabling a flexible use of the land that will gradually become more exposed to flooding and sea level rise could be an intermediate step towards retreat. This would be a way to reframe a closed window of opportunity and begin the process of turning it into something transformative. It could be where the short- and long-term planning meet and a way to reframe our way of thinking about how we live and reside in dynamic waterfront areas, and perhaps lead to a more transformative, safe, and sustainable society for future generations.
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| 6. |
- Göransson, Gunnel, et al.
(författare)
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Reträtt som en långsiktig klimatanpassningsstrategi: Utmaningar och möjligheter för Sverige : [Retreat as a long-term climate adaptation strategy: Challenges and opportunities for Sweden]
- 2024
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Ingår i: Vatten. - : Föreningen Vatten. - 0042-2886. ; 80:2, s. 69-81
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Med stigande havsnivå och mer omfattande regn blir klimatanpassning allt viktigare för Sverige men möjligheten flytta tillgångar ut ur högriskområden i situationer där traditionella lösningar inte längre är samhällsekonomiskt försvarbara förbises till stor del. Reträtt som klimatanpassningsstrategi till översvämningar handlar om att återskapa plats för vattnet när lösningen inte längre ligger i att stänga ute eller inne vattnet. Denna artikel sammanfattar ett forskningsprojekt som undersökte utmaningarna med reträtt i Sverige utifrån (i) territoriella utmaningar i fyra kommuner och ett län, (ii) invånarnas oro över klimatförändring och syn på anpassning, samt utifrån (iii) lokala, regionala och nationella myndigheters och organisationers perspektiv på planerad reträtt. Resultaten visar att även om många strandområden i Sverige ännu inte är kraftigt påverkade av effekterna av klimatförändringen, är det viktigt att börja planera långsiktigt nu för att undvika mer drastiska åtgärder i framtiden. Utmaningarna med planerad reträtt i Sverige är främst kopplade till kortsiktig ekonomi och tänkande, medan möjligheterna ligger i ett mer långsiktigt perspektiv. Lösningar för en reträttstrategi handlar inte specifikt om tekniska åtgärder utan om att forma och implementera transformativa visioner för samhällena med hänsyn till deras territoriella förutsättningar. En förståelse för det platsspecifika förutsättningarna underlättar i kommunikationen med allmänheten och även om det råder en omognad i att överväga alternativa anpassningsstrategier ses inte reträtt som omöjligt. Däremellan kan flexibla strategier för markanvändning i översvämningshotade områden vara en möjlighet för att hantera osäkerheter och som samtidigt kan skapa positiva värden på vägen.
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| 7. |
- Löfroth, Hjördis, et al.
(författare)
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Challenges in slope stability assessment of contaminated fibrous sediments along the northern Baltic coast of Sweden
- 2021
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Ingår i: Engineering Geology. - : Elsevier BV. - 0013-7952 .- 1872-6917. ; 289
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Tidskriftsartikel (refereegranskat)abstract
- In several locations along Sweden's northern Baltic coast there are deposits of contaminated fibrous sediments that are known as fiberbanks. Historically, these anthropogenic fiberbanks and associated contaminants were formed outside pulp and paper factories because of unregulated waste discharges. Some of the fiberbanks are located on seafloor slopes that are unstable and may fail, which could result in large amounts of fiber and contaminant dispersion. Hydroacoustic surveys have revealed that some parts of the fiberbanks have been dispersed to a wider area by submarine landslides. However, the unusual nature of these cellulose-rich sediments makes it difficult to apply conventional techniques for assessing submarine slope stability. Therefore, a combination of investigation techniques and interpretation methods was tested to assess the stability and triggering mechanisms for submarine slope failure identified in fiberbanks from the Ångermanälven river estuary on the Baltic sea coast. The integration of bathymetric data, sediment lithology and geotechnical characteristics from in-situ and laboratory measurements, enabled the characterisation of underlying natural sediments and the fiberbanks at two sites. Despite low densities, which indicate that the fiberbank material is near the buoyancy level, the fiberbank deposits seem to be relatively stable. Our results indicate the underlying natural sediments are also stable and would require an external triggering mechanism to generate the observed slope failures. We suggest that pore water pressure, potentially related to groundwater table fluctuations, may be an important trigger for submarine landslides in the study area.Management of fiberbanks and associated fiber-rich sediments, which are numerous along Sweden's north east coast, requires that sites are risk assessed and prioritized for remediation. To do so, under water slope stability should be considered as a possible dispersion pathway and therefore needs to be investigated. The study illustrates the value of using a combination of geophysical and geotechnical field and laboratory methods, together with empirical relationships, to assess relevant input parameters for slope stability calculations for this type of sediment.
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