Change search
Refine search result
1234567 51 - 100 of 2086
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 51.
    Andersson, Lotta
    et al.
    SMHI, Core Services.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Consequences of changed wetness on riverine nitrogen - human impact on retention vs. natural climatic variability2001In: Regional Environmental Change, ISSN 1436-3798, E-ISSN 1436-378X, Vol. 2, no 3, 93-105 p.Article in journal (Refereed)
    Abstract [en]

    The HBV-N model was used for a scenario analysis of changes in nitrogen retention and transport caused by alterations of wetness due to land drainage, lowering of lakes, building of dams and climatic variability in a river basin in south-central Sweden (1885-1994). In general, dams were situated in locations more favourable for retention, compared to the lowered lakes. Rather modest conversions of water bodies only changed nitrogen transport by about 3%. The 180-times-larger increase of (mainly) tile-drained agricultural land had, according to simulations, increased the nitrogen transport by 17%, due to reduced retention. However, compared to human-induced alteration of the landscape N retention, the choice of 10-year periods of climatological data had the overriding effect on the calculated nitrogen transport. Weather-induced variations resulted in a 13% difference in nitrogen retention between various 10-year periods. When the model was driven by climatological data from the driest 10-year period (1905-1914), the estimated average annual load was only half of that obtained with climatological data from the wettest 10-year period (1975-1984).

  • 52.
    Andersson, Lotta
    et al.
    SMHI, Core Services.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Modelling of human and climatic impact on nitrogen load in a Swedish river 1885-19942003In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 497, no 1-3, 63-77 p.Article in journal (Refereed)
    Abstract [en]

    Changes in environmental conditions within a river basin in South Central Sweden (1400 km(2)) and impacts on riverine nitrogen (N) transport were evaluated. A historical database was compiled and the process-based HBV-N model used to estimate flow normalised N loads in 1885, 1905, 1927, 1956, 1976, and 1994, using a standard climatological record (1985-1994). The study shows the value of process-based modelling in environmental impact assessment, by making it possible to assess and integrate the effect of a number of factors, both with regard to human impact and natural climatic variability. Factors taken into account include: the effects of land use, agricultural practices, atmospheric deposition, human dietary intake, use of flush toilets, lowering of lakes, building of dams, and climatic variability. For all years studied, agriculture was the overriding source of N, and changes in riverine N over time mainly reflected changes in land use and agricultural practices. In spite of decreasing N-leaching from agriculture, the net load remained fairly constant between 1885 and 1927, due to reduced N retention. Drainage of agricultural land had a dominating impact on reducing N retention, which increased the N loads, while the effects of the lowering of lake levels and dam building were less pronounced. Household N emission per capita was higher in 1994 than in 1927, as the increased consumption of meat and dairy products alone resulted in a higher increase of the emission than was compensated for with wastewater treatment improvement. In addition, introduction of flush toilets increased the emission from households. In total, the net load in 1976 was twofold higher than that in 1885, 1905 and 1927, due to increased leaching from agriculture, wastewater emission, and atmospheric deposition on lake surfaces. Finally, the impact of climatological variability was assessed, using a 110-yr climatological record. The choice of 10-yr period of climatological data was the factor that had the largest impact on calculated N load.

  • 53.
    Andersson, Lotta
    et al.
    SMHI, Core Services.
    Bonell, M
    Moody, D W
    Special thematic issue: Hydrology for the environment. life and policy (Help) Programme - Foreword2004In: International Journal of Water Resources Development, ISSN 0790-0627, E-ISSN 1360-0648, Vol. 20, no 3, 267-274 p.Article in journal (Other academic)
  • 54.
    Andersson, Lotta
    et al.
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Hellström, Sara-Sofia
    SMHI.
    Kjellström, Erik
    SMHI.
    Losjö, Katarina
    SMHI.
    Rummukainen, Marku
    SMHI.
    Samuelsson, Patrick
    SMHI.
    Wilk, Julie
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Modeling report: Climate change impacts on water resources in the Pungwe drainage basin2006Report (Other (popular science, discussion, etc.))
  • 55.
    Andersson, Lotta
    et al.
    SMHI, Core Services.
    Olsson, Johanna Alkan
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Jonsson, Anna
    Use of participatory scenario modelling as platforms in stakeholder dialogues2008In: Water S.A., ISSN 0378-4738, E-ISSN 1816-7950, Vol. 34, no 4, 439-447 p.Article in journal (Refereed)
    Abstract [en]

    A participatory methodology, based on dialogues between stakeholders and experts has been developed and tested in the drainage area to Kaggebo Bay in the Baltic Sea. This study is focused on the EU Water Framework Directive, with emphasis on reduction of eutrophication. The drainage area is included in the WFD administrative area of the Motala Strom River basin. A similar approach is now applied in a recently initiated project in the Thukela River basin, with focus on impacts of climate change on water resources. The methodology is based on the idea that a catchment model serves as a platform for the establishment of a common view of present conditions and the causes behind these conditions. In the following steps, this is followed by model-assisted agreement on environmental goals (i.e. what do we want the future to look like?) and local agreement on a remedy or mitigation plans in order to reduce environmental impact (e. g. eutrophication); alternatively to adapt to conditions that cannot be determined by local actions (e. g. climate change). By involving stakeholder groups in this model-supported stepwise process, it is ensured that all stakeholder groups involved have a high degree of confidence in the presented model results, and thereby enable various actors involved to share a common view, regarding both present conditions, goals and the way to reach these goals. Although this is a process that is time-(and cost-) consuming, it is hypothesised that the use of this methodology is two-pronged: it increases the willingness to carry out remedies or necessary adaptations to a changing environment, and it increases the level of understanding between the various groups and therefore ameliorates the potential for future conflicts. Compared to traditional use of model results in environmental decision-making, the experts' role is transformed from a one-way communication of final results to assistance in the various steps of the participatory process.

  • 56.
    Andersson, Lotta
    et al.
    SMHI, Core Services.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Pers, Charlotta
    SMHI, Research Department, Hydrology.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Estimating catchment nutrient flow with the HBV-NP model: Sensitivity to input data2005In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 34, no 7, 521-532 p.Article in journal (Refereed)
    Abstract [en]

    The dynamic catchment model HBV-N has been further developed by adding routines for phosphorus transport and is now called the HBV-NP model. The model was shown to satisfactorily simulate nutrient dynamics in the Ronnea catchment (1 900 km(2)). Its sensitivity to input data was tested, and results demonstrated the increased sensitivity to the selection of input data on a subcatchment scale when compared with the catchment scale. Selection of soil and land use databases was found to be critical in some subcatchments but did not have a significant impact on a catchment scale. Although acceptable on a catchment scale, using templates and generalization, with regards to emissions from point sources and rural households, significantly decreased model performance in certain subcatchments when compared with using more detailed local information. A division into 64 subcatchments resulted in similar model performance at the catchment outlet when compared with a lumped approach. Adjusting the imported matrixes of the regional leaching of nitrogen, from agricultural land, against mean subcatchment water percolation did not have a significant impact on the model performance.

  • 57.
    Andersson, Lotta
    et al.
    SMHI, Core Services.
    Wilk, Julie
    Graham, Phil
    SMHI, Research Department, Climate research - Rossby Centre.
    Warburton, Michele
    Design and test of a model-assisted participatory process for the formulation of a local climate adaptation plan2013In: Climate and Development, ISSN 1756-5529, E-ISSN 1756-5537, Vol. 5, no 3, 217-228 p.Article in journal (Refereed)
    Abstract [en]

    This article presents the design and testing of a model-assisted participatory process for the formulation of a local adaptation plan to climate change. The pilot study focused on small-scale and commercial agriculture, water supply, housing, wildlife, livestock and biodiversity in the Thukela River basin, KwaZulu-Natal, South Africa. The methodology was based on stakeholders identifying and ranking the severity of climate-related challenges, and downscaled stakeholder-identified information provided by modellers, with the aim of addressing possible changes of exposure in the future. The methodology enables the integration of model-based information with experience and visions based on local realities. It includes stakeholders' own assessments of their vulnerability to prevailing climate variability and the severity, if specified, of climate-related problems that may occur more often in the future. The methodology made it possible to identify the main issues to focus on in the adaptation plan, including barriers to adaptation. We make recommendations for how to design a model-assisted participatory process, emphasizing the need for transparency, to recognize the interests of the stakeholders, good advance planning, local relevance, involvement of local champions, and adaptation of Information material to each group's previous experience and understanding.

  • 58.
    Andersson, Lotta
    et al.
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Wilk, Julie
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Graham, Phil
    n/a.
    Warburton, Michele
    n/a.
    Local assessment of vulnerability to climate change impacts on water resources in the Upper Thukela River Basin, South Africa: Recommendations for Adaptation2009Report (Other academic)
    Abstract [en]

    This report originates from a project entitled Participatory Modelling for Assessment of Local Impacts of Climate Variability and Change on Water Resources (PAMO), financed by the Swedish Development Agency and Research Links cooperation (NRF and the Swedish Research Council).

    The project is based on interactions between stakeholders in the Mhlwazini/Bergville area of the Thukela River basin, climate and water researchers from the University of KwaZulu-Natal (Pietermaritzburg Campus) and the Swedish Meteorological and Hydrological Institute (SMHI) during a series of workshops held in 2007-2009. Between the workshops, the researcher’s compiled locally relevant climate change related information, based on requests from the workshop participants, as a basis for this adaptation plan.

    The aim is to provide a local assessment of vulnerability to climate change impacts on water resources and adaptation strategies. The assessment identifies existing climate-water related problems, current adaptation strategies and recommendations for future action based on likelihoods for change and the severity if such changes will occur.

  • 59.
    Andersson, Lotta
    et al.
    SMHI, Core Services.
    Wilk, Julie
    Todd, Martin C.
    Hughes, Denis A.
    Earle, Anton
    Kniveton, Dominic
    Layberry, Russet
    Savenije, Hubert H. G.
    Impact of climate change and development scenarios on flow patterns in the Okavango River2006In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 331, no 1-2, 43-57 p.Article in journal (Refereed)
    Abstract [en]

    This paper lays the foundation for the use of scenario modelling as a tool for integrated water resource management in the Okavango River basin. The Pitman hydrological model is used to assess the impact of various development and climate change scenarios on downstream river flow. The simulated impact on modelled river discharge of increased water use for domestic use, livestock, and informal irrigation (proportional to expected population increase) is very limited. Implementation of all likely potential formal irrigation schemes mentioned in available reports is expected to decrease the annual flow by 2% and the minimum monthly flow by 5%. The maximum possible impact of irrigation on annual average flow is estimated as 8%, with a reduction of minimum monthly flow by 17%. Deforestation of all areas within a 1 km buffer around the rivers is estimated to increase the flow by 6%. However, construction of all potential hydropower reservoirs in the basin may change the monthly mean flow distribution dramatically, although under the assumed operational rules, the impact of the dams is only substantial during wet years. The simulated impacts of climate change are considerable larger that those of the development scenarios (with exception of the high development scenario of hydropower schemes) although the results are sensitive to the choice of GCM and the IPCC SRES greenhouse gas (GHG) emission scenarios. The annual mean water flow predictions for the period 2020-2050 averaged over scenarios from all the four GCMs used in this study are close to the present situation for both the A2 and B2 GHG scenarios. For the 2050-2080 and 2070-2099 periods the all-GCM mean shows a flow decrease of 20% (14%) and 26% (17%), respectively, for the A2 (B2) GHG scenarios. However, the uncertainty in the magnitude of simulated future changes remains high. The simulated effect of climate change on minimum monthly flow is proportionally higher than the impact on the annual mean flow. (c) 2006 Elsevier B.V. All rights reserved.

  • 60.
    Andersson, Pia
    et al.
    SMHI, Core Services.
    Hansson, Martin
    SMHI, Core Services.
    Bjurström, Joel
    Simonsson, Daniel
    Naturtypsbestämning av miljöövervakningsstationer SMHI pelagial miljöövervakning2017Report (Other academic)
    Abstract [en]

    Sampling stations in the national environmental monitoring in the marine environment is not defined when it comes to habitat. This means that the environmental monitoring data collected cannot be properly used in the assessments connected to the Habitats Directive or the Marine Framework Strategy Directive. SwAM has funded and commissioned SMHI to explore the possibilities to in a simple manner classify the habitats for the SMHI monitoring stations. The project was intended to test the equipment and through drop video examine if it is possible, and if so, determine habitats for the open sea stations during the expedition in December, 2016. SMHI has designed a rig and conducted sampling at 11 of 25 monitoring stations. Lighting problems and weather conditions reduced the number of sampled stations. SMHI:s opinion is that the rig, with adjusted light source, is a good tool for visual investigation of the habitats at the monitoring stations in the open sea. However, we have proposed a number of adjustments to the rig to increase the quality of the images and videos and to increase the possibility to carry out further assessments of the material. Most of the images show very fine-grained material like silt / clay. A few species have been recorded and almost no vegetation. Most of the stations did not meet the criteria for the Habitat Directive . At two stations habitat was registered as 1160 Bays and sounds, containing1110 Sandbanks. For HUB Underwater biotopes, AB.H3O Baltic aphotic muddy sediments Characterized by infaunal echinoderms was registered at the station P2 and AB.M4U Baltic aphotic mixed substrate Characterized by no macro community was registered on stations BY5 and BY4. SMHI recommends a review of the collected material together with ArtDatabanken and / or additional expert to ensure the performed assessment, to ensure recommendations and to quality control and define the material to be reported to a data host. SMHI recommend additional visual sampling of the remaining stations, as well as additional sampling on stations where the quality of the image was inadequate, or where ArtDatabanken or a possible additional expert recommend additional sampling. Additional experts may recommend adding sediment sampling to the visual method at some stations. Performing visual sampling of all 25 stations, with one landing per station, will extend the expedition with approximately 11,5-13, hours.

  • 61.
    Andersson, Ramon
    Halmstad University.
    Hållbart jordbruk inom vattenskyddsområde: En studie om Sverige, Danmark, Frankrike och Tyskland2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To guarantee protection of our drinking water, water catchment protections are established. These are divided into three different zones and in the first zone it is most likely that an activity, such as agriculture, will contaminate the water resource. Hence the activities are strongly regulated or banned. The EU communion is working towards a sustained water quality through several directives; Nitrate Directive, Waterframwork directives and Sustainable use of pesticide directive. The main purpose is to regulate the diffuse pollution from agriculture.This thesis is about how Denmark, Germany and France are working towards a sustainable agriculture within water protection areas. Sweden is also discussed but mainly about two different methods applied in Linköpings and Ljungbys municipalties.How the different countries work is mainly the same due to the directives. However, there are some interesting water management methods to observe such as voluntary agreements between water companies and farmers. Moreover, the sustainability perspective is approached in a larger scale where you and I as consumers also contribute via consumer-pays-principle. Therefore, we are, by our demand for water, the problem but also the solution and together we can contribute with good social, economic and ecological conditions for ourselves and the farmer.

  • 62.
    Andin, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Sundin, Madelene
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Jämförelse av Sveriges geologiska undersöknings och Naturvårdsverkets extraktionsmetoder för metaller i morän2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 63.
    Andreasson, Arnold
    et al.
    Arnold Andreasson Konsult AB.
    Strömberg, Patrik
    SMHI, Core Services.
    Prager, Maria
    SMHI, Core Services.
    Nexelius, Nils
    SMHI, Core Services.
    Automatisering av nationellt dataflöde till ICES genom skördning - en förstudie2016Report (Other academic)
    Abstract [sv]

    SMHI är, på uppdrag av Havs- och vattenmyndigheten (HaV), datavärd för svenska marina miljöövervakningsdata. En central del i uppdraget är att årligen rapportera nationellt insamlad data till nternationella Havsforskningsrådet, ICES.

    För biologiska data sker en årlig rapportering av data levererade från föregående års övervakning. Leveranserna sker på ett format definierat av ICES. Leveransernas innehåll valideras av SMHI mot ICES valideringstjänst DATSU via uppladdning till en webbsida. När samtliga fel är rättade skickas leveranserna till ICES via e-post.

    SMHI har fått ett uppdrag från HaV att utreda om det finns en möjlighet att låta ICES skörda data som ersättning för den nuvarande hanteringen med manuella leveranser. ICES har också ett intresse av att utreda om skördning av data är en lämplig metod för framtida inhämtande av data. ICES vill även testa möjligheterna att byta leveransformat till ett nytt XML-baserat format.

    SMHI föreslår en lösning där SMHI:s tjänst för maskin-maskin-kommunikation, SHARKdata, används. SHARKdata kommer att utökas för att kunna generera exportpaket i enlighet med ICES nya XML-baserade format. ICES har även kompletterat sin valideringstjänst DATSU med ett gränssnitt för maskin-maskinkommunikation så att man med automatik kan anropa DATSU och validera exportpaket. En prototyp har utvecklats för att visa hur SHARKdata kan användas för denna typ av hantering med skördning. I prototypen ingår även konvertering till en inledande testversion av XML-formatet för datatypen Zoobenthos.

    Det fortsatta projektet efter denna förstudie planeras som ett samarbete mellan SMHI och ICES. SMHI utvecklar fortlöpande SHARKdata i takt med att ICES släpper specifikationer på format för nya datatyper, parallellt med att data rapporteras på nuvarande sätt. Detta arbete beräknas pågå under 2016 och 2017, med varierande intensitet. Efter denna test- och utvecklingsperiod antas ICES släppa en ny version av sitt rapporteringformat och då kan SMHI gå över till det nya rapporteringssättet.

  • 64. Andrejev, Oleg
    et al.
    Soomere, Tarmo
    Sokolov, Alexander
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Myrberg, Kai
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    The role of the spatial resolution of a three-dimensional hydrodynamic model for marine transport risk assessment2011In: Oceanologia, ISSN 0078-3234, Vol. 53, no 1, 309-334 p.Article in journal (Refereed)
    Abstract [en]

    The paper addresses the sensitivity of a novel method for quantifying the environmental risks associated with the current-driven transport of adverse impacts released from offshore sources (e.g. ship traffic) with respect to the spatial resolution of the underlying hydrodynamic model. The risk is evaluated as the probability of particles released in different sea areas hitting the coast and in terms of the time after which the hit occurs (particle age) on the basis of a statistical analysis of large sets of 10-day long Lagrangian trajectories calculated for 1987-1991 for the Gulf of Finland, the Baltic Sea. The relevant 21) maps are calculated using the OAAS model with spatial resolutions of 2, 1 and 0.5 nautical miles (nm) and with identical initial, boundary and forcing conditions from the Rossby Centre 3D hydrodynamic model (RCO, Swedish Meteorological and Hydrological Institute). The spatially averaged values of the probability and particle age display hardly any dependence on the resolution. They both reach almost identical stationary levels (0.67-0.69 and ca 5.3 days respectively) after a few years of simulations. Also, the spatial distributions of the relevant fields are qualitatively similar for all resolutions. In contrast, the optimum locations for fairways depend substantially on the resolution, whereas the results for the 2 nm model differ considerably from those obtained using finer-resolution models. It is concluded that eddy-permitting models with a grid step exceeding half the local baroclinic Rossby radius are suitable for a quick check of whether or not any potential gain from this method is feasible, whereas higher-resolution simulations with eddy-resolving models are necessary for detailed planning. The asymptotic values of the average probability and particle age are suggested as an indicator of the potential gain from the method in question and also as a new measure of the vulnerability of the nearshore of water bodies to offshore traffic accidents.

  • 65.
    André, Karin
    et al.
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Simonsson, Louise
    Linköping University, The Tema Institute, Centre for Climate Science and Policy Research . Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Identification of regional stakeholders for adaptation to climate change:  2009In:  , 2009Conference paper (Other academic)
    Abstract [en]

    To improve decisions and awareness considering climate change it is argued that stakeholder interaction and dialogue is essential. Engaging stakeholders in research on adaptation thus requires analysis of stakeholder landscape and identification of relevant actors at different levels in society. The term 'stakeholder' is broad and researchers and practitioners might have both interrelated and contrasting views on who is at stake, the need for adaptation and climate risks.

    The aim of this paper is to analyse the stakeholder landscape in a Swedish region, as part of increasing the understanding of the adaptation process. The stakeholder analysis has been initiated by the research teams through stakeholder mapping and complemented by local and regional actors' notions of who is, or should be, involved and active stakeholders in adaptation to climate change. The results indicate the importance of careful stakeholder analysis for sustainable adaptation. The actors' expert knowledge of the regions deepens the picture, show important links and gaps between different actors and illuminate unclear relationships and responsibilities as well as identify those actors who have important roles to play.

  • 66.
    Andréasson, Johan
    et al.
    SMHI, Professional Services.
    Bergström, Sten
    SMHI, Research Department, Hydrology.
    Carlsson, Bengt
    SMHI, Research Department, Hydrology.
    Graham, Phil
    SMHI, Research Department, Climate research - Rossby Centre.
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Hydrological change - Climate change impact simulations for Sweden2004In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 33, no 4-5, 228-234 p.Article in journal (Refereed)
    Abstract [en]

    Climate change resulting from the enhanced greenhouse effect is expected to give rise to changes in hydrological systems. This hydrological change, as with the change in climate variables, will vary regionally around the globe. Impact studies at local and regional scales are needed to assess how different regions will be affected. This study focuses on assessment of hydrological impacts of climate change over a wide range of Swedish basins. Different methods of transferring the signal of climate change from climate models to hydrological models were used. Several hydrological model simulations using regional climate model scenarios from Swedish Regional Climate Modelling Programme (SWECLIM) are presented. A principal conclusion is that subregional impacts to river flow vary considerably according to whether a basin is in northern or southern Sweden. Furthermore, projected hydrological change is just as dependent on the choice of the global climate model used for regional climate model boundary conditions as the choice of anthropogenic emissions scenario.

  • 67.
    Andrén, Hanna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences.
    Tillförlitligheten hos översvämningskartering: Utbredningsjämförelse med översvämningen i Hallsberg 20152016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
  • 68.
    Angirekula, Ravi Kumar
    Linköping University, The Tema Institute, Department of Water and Environmental Studies.
    Low-Cost treatment methods for purification of Phenolic compounds suitable for ASEAN Agro/forest Industrial Wastewater2006Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    Rapid industrialization of South East Asian countries is causing severe industrial wastewater pollution. Large number of agro/forest industries such as agro-chemicals, rubber, oil palm, pulp and paper and wood preserving industries are contributing major role in industrial pollution. These industries discharging huge amounts of organic pollutants like phenolic compounds into the environment. Phenolic compounds showing significant negative impacts on water resources, aquatic life and human health. The growing problems of industrial wastewater pollution are exacerbated for many developing countries which cannot afford to construct or operate conventional wastewater treatment facilities. It has thus become imperative to develop and popularize low-cost and energy-saving technologies for wastewater treatment. Lack of treatment facilities, feeble environmental legislations and less financial resources of agro-forest industries are might be the some of causes for present situation of industrial pollution. This paper analyzed different low cost treatment methods such as stabilization ponds, constructed treatment wetlands, bioadsorbents and adsorption process on activated carbons prepared from low cost agro/forest based waste byproducts to purify the phenolic compounds present in the agro/forest industrial wastewaters. And also it analyzed the suitability of treatment methods for the circumstances and conditions of agro/forest based industries of ASEAN countries. Based on different factors such as suitability of any kind of physical, chemical and biological conditions, low cost, availability of raw material and availability land adsorption process on low cost activated carbons seem to be most promising treatment method for purification of phenols in ASEAN agro/forest industrial wastewaters.

  • 69. Archfield, Stacey A.
    et al.
    Clark, Martyn
    Arheimer, Berit
    Hay, Lauren E.
    McMillan, Hilary
    Kiang, Julie E.
    Seibert, J.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Hakala, Kirsti
    Bock, Andrew
    Wagener, Thorsten
    Farmer, William H.
    Andreassian, Vazken
    Attinger, Sabine
    Viglione, Alberto
    Knight, Rodney
    Markstrom, Steven
    Over, Thomas
    Accelerating advances in continental domain hydrologic modeling2015In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 51, no 12, 10078-10091 p.Article in journal (Refereed)
    Abstract [en]

    In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

  • 70. Archfield, Stacey A.
    et al.
    Clark, Martyn
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Hay, Lauren E.
    McMillan, Hilary
    Kiang, Julie E.
    Seibert, Jan
    Hakala, Kirsti
    Bock, Andrew
    Wagener, Thorsten
    Farmer, William H.
    Andreassian, Vazken
    Attinger, Sabine
    Viglione, Alberto
    Knight, Rodney
    Markstrom, Steven
    Over, Thomas
    Accelerating advances in continental domain hydrologic modeling2015In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 51, no 12, 10078-10091 p.Article in journal (Refereed)
    Abstract [en]

    In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

  • 71.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Andersson, Lotta
    SMHI, Core Services.
    Alkan-Olsson, J.
    Jonsson, A.
    Using catchment models to establish measure plans according to the Water Framework Directive2007In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 56, no 1, 21-28 p.Article in journal (Refereed)
    Abstract [en]

    A participatory modelling process (DEMO) has been developed and applied in a 350 km(2) catchment in southern Sweden. The overall goal is to improve the dialogues between experts and local stakeholders by using numerical models as a platform for discussions. The study is focused on reducing nutrient load and on the development of a locally established measure plan, which is requested by the European Water Framework Directive. The HBV-NP model was chosen as it can calculate effects and costs for different allocations of several combined measures in a catchment. This paper shows the impact of including local data in the modelling process vs. using more general data. It was found that modelled diffuse nutrient pollution was highly modified when including local know-how, soft information and more detailed field investigations. Leaching from arable land was found to be 35% higher using more detailed information on for instance, agricultural practices, crop and soil distribution. Moreover, the stakeholders' acceptance of model results and reliance on experts was increased by applying the participatory process and involving stakeholders in the modelling procedure.

  • 72.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Andersson, Lotta
    SMHI, Core Services.
    Larsson, M
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Pers, Charlotta
    SMHI, Research Department, Hydrology.
    Modelling diffuse nutrient flow in eutrophication control scenarios2004In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 49, no 3, 37-45 p.Article in journal (Refereed)
    Abstract [en]

    The Swedish Water Management Research Programme (VASTRA) focuses on the development and demonstration of tools for more efficient eutrophication control when implementing the EU water framework directive in Sweden. During the first half of the programme, models for nitrogen flow were developed, and at present, similar models for phosphorus are under construction (e.g. HBV-P). The programme is interdisciplinary, and scientists are collaborating in actor-games and focus group evaluations including scenario analysis. The scenarios modelled in VASTRA phase 1, show that (i) changed agricultural practices can be the most effective and-least expensive way to reduce nitrogen transport from land to, the sea; (ii) constructed agricultural wetlands may only have small impact on riverine nitrogen transport in some regions, due to natural hydrometeorological dynamics; (iii) removing planktivorous fish may be an efficient way of reducing the algal concentrations in lakes without the undesired side-effect of increased nutrient load to the down-stream river system. In VASTRA phase 11, one of the highlights will be interdisciplinary scenario-modelling of different measure strategies in a pilot catchment of southern Sweden (Ronne a).

  • 73.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Andreasson, Johan
    SMHI, Professional Services.
    Fogelberg, S
    Johnsson, H
    Pers, Charlotta
    SMHI, Research Department, Hydrology.
    Persson, K
    Climate change impact on water quality: Model results from southern Sweden2005In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 34, no 7, 559-566 p.Article in journal (Refereed)
    Abstract [en]

    Starting from six regional climate change scenarios, nitrogen leaching from arable-soil, water discharge, and nitrogen retention was modeled in the Ronnea catchment. Additionally, biological response was modeled in the eutrophic Lake Ringsjon. The results are compared with similar studies on other catchments. All scenarios gave similar impact on water quality but varied in quantities. However, one scenario resulted in a different transport pattern due to less-pronounced seasonal variations in the hydrology. On average, the study shows that, in a future climate, we might expect: i) increased concentrations of nitrogen in the arable root zone (+50%) and in the river (+13%); ii) increased annual load of nitrogen from land to sea (+22%) due to more pronounced winter high flow; moreover, remote areas in the catchment may start to contribute to the outlet load; iii) radical changes in lake biochemistry with increased concentrations of total phosphorus (+50%), total nitrogen (+20%), and planktonic algae such as cyanobacteria (+80%).

  • 74.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Brandt, Maja
    SMHI, Research Department, Hydrology.
    Modelling nitrogen transport and retention in the catchments of southern Sweden1998In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 27, no 6, 471-480 p.Article in journal (Refereed)
    Abstract [en]

    The Baltic Sea is suffering from eutrophication and attempts are being made to reduce nutrient loads. This article focuses on nitrogen transport from southern Sweden (145 000 km(2)), and presents a model approach (HBV-N) that has been used in the national decision-making process for best management practices. Calculations of nitrogen leaching, retention in the freshwater system, net transport to the sea, and source apportionment are presented for the period 1985-1994. Input data were handled in GIS, including results from SOIL-N and MATCH. Daily simulations were made in 3725 subbasins with calibration against measured time series at 722 sites. Diffuse source pollution was normally retained by 10-25% before entering the river network. Lakes normally reduced nitrogen transport by 30-40 kg ha(-1) yr(-1) of lake area. On average, 45% of the annual gross load was reduced during transport, but temporal and spatial variations were great. 75 000 tonnes N yr(-1) reached the sea.

  • 75.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Brandt, Maja
    SMHI, Research Department, Hydrology.
    Watershed modelling of nonpoint nitrogen losses from arable land to the Swedish coast in 1985 and 19942000In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 14, no 4, 389-404 p.Article in journal (Refereed)
    Abstract [en]

    Eutrophication problems in the Baltic Sea have drawn attention to the contribution of nutrients from surrounding countries. By using the HBV-N model in southern Sweden (145 000 km(2)) daily nitrogen leaching, reduction in rivers and lakes, net transport to the sea and source apportionment have been calculated in 3725 subbasins for the period 1985-1994, with calibration at 722 sites against measured time series. On average, 48% of the nonpoint losses from agriculture were reduced during the transport towards the sea, which left about 33 500 tonnes in annual mean net transport. This represents 45% of the total land-based load. Land cover and emissions for the years of 1985 and 1994 were used in two separate simulations of the 10-year period. The normalized gross leakage from arable land in 1985 was estimated to 29 kg N ha(-1) year(-1), which corresponds to 15 kg N ha(-1) year(-1) in net leakage to the sea. In 1994 these transports were reduced by 20 and 15%, and thereby the total load on the sea was decreased by 7%. This is still far from the Swedish goal of 50% reduction. The article presents the spatial variation of nitrogen leakage and retention within the southern half of Sweden, and emphasizes the importance of allocating measures where down-stream retention is low in order to achieve efficiency with respect to the sea. It is shown that the model approach may be used in the decision making process for best management practices in watersheds. (C) 2000 Elsevier Science B.V. All rights reserved.

  • 76.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Dahne, Joel
    SMHI, Professional Services.
    Donnelly, Chantal
    SMHI, Research Department, Hydrology.
    Climate Change Impact on Riverine Nutrient Load and Land-Based Remedial Measures of the Baltic Sea Action Plan2012In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, no 6, 600-612 p.Article in journal (Refereed)
    Abstract [en]

    To reduce eutrophication of the Baltic Sea, all nine surrounding countries have agreed upon reduction targets in the HELCOM Baltic Sea Action Plan (BSAP). Yet, monitoring sites and model concepts for decision support are few. To provide one more tool for analysis of water and nutrient fluxes in the Baltic Sea basin, the HYPE model has been applied to the region (called Balt-HYPE). It was used here for experimenting with land-based remedial measures and future climate projections to quantify the impacts of these on water and nutrient loads to the sea. The results suggest that there is a possibility to reach the BSAP nutrient reduction targets by 2100, and that climate change may both aggravate and help in some aspects. Uncertainties in the model results are large, mainly due to the spread of the climate model projections, but also due to the hydrological model.

  • 77.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Dahne, Joel
    SMHI, Professional Services.
    Donnelly, Chantal
    SMHI, Research Department, Hydrology.
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Strömqvist, Johan
    SMHI, Research Department, Hydrology.
    Water and nutrient simulations using the HYPE model for Sweden vs. the Baltic Sea basin - influence of input-data quality and scale2012In: HYDROLOGY RESEARCH, ISSN 1998-9563, Vol. 43, no 4, 315-329 p.Article in journal (Refereed)
    Abstract [en]

    Water resource management is often based on numerical models, and large-scale models are sometimes used for international strategic agreements. Sometimes the modelled area entails several political entities and river basins. To avoid methodological bias in results, methods and databases should be homogenous across political and geophysical boundaries, but this may involve fewer details and more assumptions. This paper quantifies the uncertainty when the same model code is applied using two different input datasets; a more detailed one for the country of Sweden (S-HYPE) and a more general one for the entire Baltic Sea basin (Balt-HYPE). Results from the two model applications were compared for the Swedish landmass and for two specific Swedish river basins. The results show that both model applications may be useful in providing spatial information of water and nutrients at various scales. For water discharge, most relative errors are <10% for S-HYPE and <25% for Balt-HYPE. Both applications reproduced the most mean concentration for nitrogen within 25% of the observed mean values, but phosphorus showed a larger scatter. Differences in model set-up were reflected in the simulation of both spatial and temporal dynamics. The most sensitive data were precipitation/temperature, agriculture and model parameter values.

  • 78.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Donnelly, Chantal
    SMHI, Research Department, Hydrology.
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Regulation of snow-fed rivers affects flow regimes more than climate change2017In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, 62Article in journal (Refereed)
  • 79.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Lidén, R.
    SMHI.
    Nitrogen and phosphorus concentrations from agricultural catchments - influence of spatial and temporal variables2000In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 227, no 1-4, 140-159 p.Article in journal (Refereed)
    Abstract [en]

    The eutrophication problem has drawn attention to nutrient leaching from arable land in southern Sweden, and further understanding of spatial and temporal variability is needed in order to develop decision-making tools. Thus, the influence of spatial and temporal variables was analysed statistically using empirical time series of different nutrient species from 35 well-documented catchments (2-35 km(2)), which have been monitored for an average of 5 years. In the spatial analysis several significant correlations between winter median concentrations and catchment characteristics were found. The strongest correlation was found between inorganic nitrogen and land use, while concentrations of different phosphorus species were highly correlated to soil texture. Multiple linear regression models gave satisfactory results for prediction of median winter concentrations in unmeasured catchments, especially for inorganic nitrogen and phosphate. In the analysis of temporal variability within catchments, internal variables from a dynamic hydrological model (HBV) were linked to concentration fluxes. It was found that phosphorus and inorganic nitrogen concentrations were elevated during flow increase at low-Bow conditions, while they were diluted as the wetness in the catchment increased. During unmonitored periods regression models were successful in predicting temporal variability of total phosphorus, phosphate and inorganic nitrogen, while organic nitrogen and particulate phosphorus could not be predicted with this approach. Dividing the data into different flow categories did not improve the prediction of nutrient concentration dynamics. The results and literature review presented, confirm parts of the present HBV-W model approach and will be useful for further development of nutrient routines linked to dynamic hydrological models. (C) 2000 Elsevier Science B.V. All rights reserved.

  • 80.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Climate impact on floods: changes in high flows in Sweden in the past and the future (1911-2100)2015In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 19, no 2, 771-784 p.Article in journal (Refereed)
    Abstract [en]

    There is an ongoing discussion whether floods occur more frequently today than in the past, and whether they will increase in number and magnitude in the future. To explore this issue in Sweden, we merged observed time series for the past century from 69 gauging sites throughout the country (450 000 km(2)) with high-resolution dynamic model projections of the upcoming century. The results show that the changes in annual maximum daily flows in Sweden oscillate between dry and wet periods but exhibit no significant trend over the past 100 years. Temperature was found to be the strongest climate driver of changes in river high flows, which are related primarily to snowmelt in Sweden. Annual daily high flows may decrease by on average -1% per decade in the future, mainly due to lower peaks from snowmelt in the spring (-2% per decade) as a result of higher temperatures and a shorter snow season. In contrast, autumn flows may increase by + 3% per decade due to more intense rainfall. This indicates a shift in floodgenerating processes in the future, with greater influence of rain-fed floods. Changes in climate may have a more significant impact on some specific rivers than on the average for the whole country. Our results suggest that the temporal pattern in future daily high flow in some catchments will shift in time, with spring floods in the northern-central part of Sweden occurring about 1 month earlier than today. High flows in the southern part of the country may become more frequent. Moreover, the current boundary between snow-driven floods in northern-central Sweden and rain-driven floods in the south may move toward higher latitudes due to less snow accumulation in the south and at low altitudes. The findings also indicate a tendency in observations toward the modeled projections for timing of daily high flows over the last 25 years. Uncertainties related to both the observed data and the complex model chain of climate impact assessments in hydrology are discussed.

  • 81.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    A systematic review of sensitivities in the Swedish flood-forecasting system2011In: Atmospheric research, ISSN 0169-8095, E-ISSN 1873-2895, Vol. 100, no 2-3, 275-284 p.Article, review/survey (Refereed)
    Abstract [en]

    Since the early 1970s operational flood forecasts in Sweden have been based on the hydrological HBV model. However, the model is only one component in a chain of processes for production of hydrological forecasts. During the last 35 years there has been considerable work on improving different parts of the forecast procedure and results from specific studies have been reported frequently. Yet, the results have not been compared in any overall assessment of potential for improvements. Therefore we formulated and applied a method for translating results from different studies to a common criterion of error reduction. The aim was to quantify potential improvements in a systems perspective and to identify in which part of the production chain efforts would result in significantly better forecasts. The most sensitive (> 20% error reduction) components were identified for three different operational-forecast types. From the analyses of historical efforts to minimise the errors in the Swedish flood-forecasting system, it was concluded that 1) general runoff simulations and predictions could be significantly improved by model structure and calibration, model equations (e.g. evapotranspiration expression), and new precipitation input using radar data as a complement to station gauges; 2) annual spring-flood forecasts could be significantly improved by better seasonal meteorological forecast, fresh re-calibration of the hydrological model based on long time-series, and data assimilation of snow-pack measurements using georadar or gamma-ray technique; 3) short-term (2 days) forecasts could be significantly improved by up-dating using an auto-regressive method for discharge, and by ensembles of meteorological forecasts using the median at occasions when the deterministic forecast is out of the ensemble range. The study emphasises the importance of continuously evaluating the entire production chain to search for potential improvements of hydrological forecasts in the operational environment. (C) 2010 Elsevier B.V. All rights reserved.

  • 82.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Lowgren, M
    Pers, Charlotta
    SMHI, Research Department, Hydrology.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Integrated catchment modeling for nutrient reduction: Scenarios showing impacts, potential, and cost of measures2005In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 34, no 7, 513-520 p.Article in journal (Refereed)
    Abstract [en]

    A hydrological-based model (HBV-NP) was applied to a catchment (1900 km(2)) in the southern part of Sweden. Careful characterization of the present load situation and the potential for improved treatment or reduced soil leaching were analyzed. Several scenarios were modeled to find strategies to reach the Swedish environmental goals of reducing anthropogenic nitrogen load by 30% and phosphorus load by 20%. It was stated that the goals could be reached by different approaches that would affect different polluters and social sectors. However, no single measure was enough by itself. Instead, a combination of measures was necessary to achieve the goals. The nitrogen goal was the most difficult to attain. In order to be cost-effective, these measures should be applied to areas contributing the most to the net loading of the sea. This strategy could reduce the costs by 70%-80% when compared with implementing the measures in the entire catchment. Integrated catchment models may thus be helpful tools for reducing costs in environmental control programs.

  • 83.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Nilsson, Johanna
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Experimenting with Coupled Hydro-Ecological Models to Explore Measure Plans and Water Quality Goals in a Semi-Enclosed Swedish Bay2015In: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 7, no 7, 3906-3924 p.Article in journal (Refereed)
    Abstract [en]

    Measure plans are currently being developed for the Water Framework Directive (WFD) by European water authorities. In Sweden, such plans include measures for good ecological status in the coastal ecosystem. However, the effect of suggested measures is not yet known. We therefore experimented with different nutrient reduction measures on land and in the sea, using a model system of two coupled dynamic models for a semi-enclosed bay and its catchment. The science question was whether it is worthwhile to implement measures in the local catchment area to reach local environmental goals, or if the status of the Bay is more governed by the water exchange with the Sea. The results indicate that by combining several measures in the catchment, the nutrient load can be reduced by 15%-20%. To reach the same effect on nutrient concentrations in the Bay, the concentrations of the sea must be reduced by 80%. Hence, in this case, local measures have a stronger impact on coastal water quality. The experiment also show that the present targets for good ecological status set up by the Swedish water authorities may be unrealistic for this Bay. Finally, we discuss when and how to use hydro-ecological models for societal needs.

  • 84.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Pers, Charlotta
    SMHI, Research Department, Hydrology.
    Lessons learned? Effects of nutrient reductions from constructing wetlands in 1996–2006 across Sweden2016In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, 1-11 p.Article in journal (Refereed)
  • 85.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Torstensson, G
    Wittgren, Hans Bertil
    SMHI, Research Department.
    Landscape planning to reduce coastal eutrophication: agricultural practices and constructed wetlands2004In: Landscape and Urban Planning, ISSN 0169-2046, E-ISSN 1872-6062, Vol. 67, no 1-4, 205-215 p.Article in journal (Refereed)
    Abstract [en]

    Southern Sweden suffers from coastal eutrophication and one reason is the high nitrogen load through rivers. The major part of this load originates from diffuse land-based sources, e.g. arable soil leaching. Effective reduction of load from such sources demand careful landscape analysis, combined with changed behaviour of the stakeholders. This study describes a chain of methods to achieve trustworthy management plans that are based on numerical modelling and stakeholders participation and acceptance. The effect of some measures was unexpected when modelling their impact on the catchment scale. Management scenarios to reduce riverine nitrogen load were constructed in an actor game (i.e. role-play) for the Genevadsan catchment in southern Sweden. The game included stakeholders for implementation of a loading standard for maximum nitrogen transport at the river mouth. Scenarios were defined after negotiation among involved actors and included changes in agricultural practices, improved wastewater treatment, and establishment of wetlands. Numerical models were used to calculate the nitrogen reduction for different measures in each scenario. An index model (STANK) calculated the root zone leaching of nitrogen from crops at four type farms. This generated input to a catchment scale model (HBV-N) and farm economics. The economic impact of different sets of remedial measures was evaluated for each type farm and then extrapolated to the catchment. The results from scenario modelling show that possible changes in agricultural practices (such as tuning, timing of fertilisation and ploughing, changed crop cultivation) could reduce the nitrogen load to the sea by some 30%, while wetland construction only reduced the original load by some 5%. In the most cost-effective scenario agricultural practices could reduce the riverine load by 86 t per year at a cost of 1.0 million SEK, while constructed wetlands only reduced the load by 14 t per year at a cost of 1.7 million SEK. Thus, changed agricultural practices can be the most effective and less expensive way to reduce nitrogen transport from land to the sea, while constructed wetlands with realistic allocations and sizes may only have small impact on riverine nitrogen transport from land to sea. The overall experience is that actor games and numerical modelling are useful tools in landscape planning for analysing stakeholders' behaviour and the impact of measures to reduce coastal eutrophication. (C) 2003 Elsevier Science B.V. All rights reserved.

  • 86.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Wittgren, H B
    Modelling nitrogen removal in potential wetlands at the catchment scale2002In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 19, no 1, 63-80 p.Article in journal (Refereed)
    Abstract [en]

    The reduction of nitrogen fluxes from land to sea is an important task in areas with estuarine or marine eutrophication. Wetland creation has been proposed as one method to reduce nitrogen from streams draining agricultural areas. In this study, a scenario of nitrogen removal in created wetlands was evaluated by mathematical modelling of nitrogen fluxes in a catchment (224 km(2)) in southern Sweden. The scenario was based on topographically realistic siting of 40 potential wetlands with a total area of 0.92 km(2) (0.4% of the catchment area). Nitrogen removal in the wetlands was described with a simple and robust first-order model, which was modified and evaluated against data from eight monitored surface-flow wetlands. However, the modifications gave no substantial support for changing the basic model. For catchment-scale modelling this wetland model was incorporated into a dynamic process-based catchment model (HBV-N). The catchment was then divided to several coupled subbasins, so that the wetland influence on nitrogen load could be estimated separately for each potential wetland. The modelling showed that the 40 potential wetlands would reduce the nitrogen transport to the coast with approximately 6%. Specific removal rates ranged between 57 and 466 kg ha(-1) yr(-1) for the different wetlands, depending on residence time (size and hydraulic loading) and nitrogen concentration in inflow. Due to temperature dependence and seasonal variation in water discharge, significant decrease in nitrogen concentrations mainly occurred during summer periods with low loading. The study illustrates that catchment modelling is a useful method for analysing wetland creation plans, and that wetland creation must cover fairly large areas and be combined with other measures in order to achieve substantial reduction of nitrogen fluxes to coastal waters. Further monitoring of existing wetlands will improve the removal expression and decrease uncertainty. For instance, at present it could not be deducted whether wetlands with low average residence times ( < 2 days) have net removal or net resuspension on an annual basis. (C) 2002 Elsevier Science B.V. All rights reserved.

  • 87.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Wittgren, Hans Bertil
    SMHI, Research Department.
    MODELING THE EFFECTS OF WETLANDS ON REGIONAL NITROGEN TRANSPORT1994In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 23, no 6, 378-386 p.Article in journal (Refereed)
    Abstract [en]

    Created wetlands have been suggested as a method to reduce nitrogen transport to the Baltic Sea. This paper presents a dynamic conceptual model for simulation of the hypothetical effect of wetlands on nitrogen export to the coastal zone. The study was performed in the Soder-kopingsan drainage basin (882 km(2)) in southeastern Sweden, discharging into the Baltic Sea. An empirically based routine for wetland retention was calibrated separately and incorporated in the model. Scenarios with different location and size of wetlands were analyzed. It was estimated that conversion of 1% (8.8 km(2)) of this basin into wetlands would reduce the nitrogen transport by 10-16% and that more than 5% (45 km(2)) conversion to wetlands is required to reduce the transport by 50%. It was concluded that creation of wetlands should be considered, primarily, downstream from major lakes, in coastal areas, and where the summer load is a significant portion of the annual load. Some further conclusions from the study were that: i) the net reduction of nitrogen transport per unit area of wetland decreases with increasing total area of wetlands in a drainage basin; ii) the wetland retention efficiency obtained in studies of individual wetlands can not be extrapolated in a linear fashion to estimate the net reduction of nitrogen transport at the mouth of a whole drainage basin; iii) the seasonal hydrological and hydrochemical dynamics are of fundamental importance for wetland retention efficiency, which complicates comparison and extrapolation of results from one region to another.

  • 88. Arnbjerg-Nielsen, K.
    et al.
    Willems, P.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Beecham, S.
    Pathirana, A.
    Gregersen, I. Bulow
    Madsen, H.
    Nguyen, V. -T-V
    Impacts of climate change on rainfall extremes and urban drainage systems: a review2013In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 68, no 1, 16-28 p.Article, review/survey (Refereed)
    Abstract [en]

    A review is made of current methods for assessing future changes in urban rainfall extremes and their effects on urban drainage systems, due to anthropogenic-induced climate change. The review concludes that in spite of significant advances there are still many limitations in our understanding of how to describe precipitation patterns in a changing climate in order to design and operate urban drainage infrastructure. Climate change may well be the driver that ensures that changes in urban drainage paradigms are identified and suitable solutions implemented. Design and optimization of urban drainage infrastructure considering climate change impacts and co-optimizing these with other objectives will become ever more important to keep our cities habitable into the future.

  • 89.
    Arneborg, Lars
    et al.
    SMHI, Research Department, Oceanography.
    Jansson, Par
    Staalstrom, Andre
    Broström, Göran
    Tidal Energy Loss, Internal Tide Radiation, and Local Dissipation for Two-Layer Tidal Flow over a Sill2017In: Journal of Physical Oceanography, ISSN 0022-3670, E-ISSN 1520-0485, Vol. 47, no 7, 1521-1538 p.Article in journal (Refereed)
  • 90.
    Arnesten, Emilie
    Kristianstad University, School of Education and Environment.
    Hydroarkeologi på Västgötaslätten: en kartstudie av sambandet mellan fornlämningar och förhistorisk hydrologi.2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor thesis investigates hydroarchelogy through several studies of maps, ancient remains and their relationship to the hydrology of the prehistoric landscape in a selected area in Sweden where a prehistoric hydrological situation has been recreated. The focus of this thesis is remains which are located over 1 000 meters from a body of water today, but which have water within 1 000 meters on historical maps.

     

    Ancient remains are generally situated relatively close to the present bodies of water and among the studied remains the dominating types are graves and tools. The majority of the remains date back to the prehistory and between the 18th century and today the land use surrounding the remains has consisted of an increasing part of open field. The water has changed both by natural and antropogen causes and the major antropogen changes started around 1800. The studied area probably has a totally different hydrological appearance today compared to during the prehistory.

  • 91.
    Arnlund, Jonathan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Utredning av reningsfunktionen hos Kungsängens dagvattendamm: en studie med flödesproportionell provtagning2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Stormwater is the name for rainwater and snowmelt runoff from impervious surfaces in the urban environment. This water often carries large amounts of pollutants such as heavy metals, nutrients, and oil-related substances, which can cause great damage if they reach the receiving waters. To clean the storm water and thus reduce the pollution load, more and more open storm water systems are being built, such as wetlands and ponds. Studies have shown that these systems have high pollutant removal efficiency and are cost effective. Knowledge of how these systems work and how they best are evaluated is limited.

    “Kungsängsdammen” near Uppsala is a newly constructed stormwater facility that is designed to clean and retard stormwater from the industrial and commercial area Boländerna. This thesis aims to investigate the purification function of the facility. Flow proportional sampling was carried out at the inlet and outlet for 8 weeks. Substances that were analyzed were nutrients P and N, suspended solids, heavy metals As, Cd, Co, Cr, Cu, Mo, Ni, Pb, V, Zn and petroleum hydrocarbons. On some occasions, the petroleum-related organic parameters PAHs, octyl and nonylphenols and tributyltin were analyzed. Flow proportional sampling is recommended to determine the efficiency of a stormwater pond, but the problem is that it takes much time and considerable resources. In addition to this method, additional measurements were carried out with sediment traps, and a calculation of pollution load at the inlet with the program StormTac.

    The flow proportional sampling showed that the “Kungsängsdammen” pond-, functions well as a treatment facility for pollutions. Suspended solids, nutrients and heavy metals are separated effectively and the outlet concentrations for these substances were below proposed guideline values. This is observed, despite the fact that zinc, copper, nitrogen and suspended solids had intake concentrations above the guideline values. Flow calculations showed that the bypass flow is important when estimating the pollutant removal efficiency. For organic compounds, tributyltin was measured at concentrations above the Environmental Quality Standards (EQS) for surface water both at the inlet and outlet. The inlet concentrations that were calculated in StormTac were consistent with the results of the flow proportional sampling for heavy metals and nutrients. Moreover, the investigation of sediments showed that sedimentation occurs mainly in the ditch before the pond and at the inlet to the pond. The ditch is in need of cleansing, because of the risk of sediment being washed away during high flows.

    The flow proportional sampling showed that the “Kungsängsdammen” pond-, functions wellas a treatment facility for pollutions. Suspended solids, nutrients and heavy metals are separated effectively and the outlet concentrations for these substances were below proposedguideline values. This is observed, despite the fact that zinc, copper, nitrogen and suspended solids had intake concentrations above the guideline values. Flow calculations showed that the bypass flow is important when estimating the pollutant removal efficiency. For organiccompounds, tributyltin was measured at concentrations above the Environmental Quality Standards (EQS) for surface water both at the inlet and outlet. The inlet concentrations that were calculated in StormTac were consistent with the results of the flow proportional sampling for heavy metals and nutrients. Moreover, the investigation of sediments showedthat sedimentation occurs mainly in the ditch before the pond and at the inlet to the pond. The ditch is in need of cleansing, because of the risk of sediment being washed away during high flows.

  • 92.
    Arnold, Eve
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    ECORD Teachers Workshop: Exploring the Ocean Floor with the Integrated Ocean Drilling Program2007In: European Geosciences Union, 2007Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    The Earth’s oceans are important regions of research exploration because they play key roles in driving the Earth’s climate, are very geologically active and preserve sedimentary and rock records that provide a detailed climate and tectonic history of the Earth over the last 200 million years. The Integrated Ocean Drilling Program (IODP) is the only international research program that provides scientists from all over the world with long, continuous sediment and rock records to study the Earth’s history in these very important regions. The European Consortium for Ocean Research Drilling (ECORD) is the European branch of IODP, which also includes scientists from the USA, Japan, the People’s Republic of China and South Korea.

    The goal of the ECORD workshop is to provide teachers with information and material that can be used to enhance science classes for school students and to illustrate the excitement found in ocean research drilling.

    Scientific talks designed specifically for school teachers by leading IODP scientists will highlight selected ocean drilling research topics important for humanity such as natural resources (gas hydrates), natural hazards (earthquakes, volcanic activity, undersea landslides and tsunamis) and natural climate variation (growth and decline of ice sheets and sea level change).

    The ECORD teacher’s workshop will also provide teachers with background speeches that introduce the highly specialized IODP research ships that drill sediment and rock cores for scientific studies, as well as an introduction to the international IODP websites where teachers and students can obtain scientific results, real-time information about current research cruises, and learning materials for use in their classrooms.

  • 93.
    Arnold, Karin von
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Forests and Greenhouse gases. Fluxes of CO2, CH4 and N2O from drained forests on organic soils2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    One of the largest environmental threats believed to be facing us today is global warming due to the accumulation of green house gases (GHG). The concentrations of GHG in the atmosphere are a result of the net strength of different sinks and sources. Forests, in this context, are of particular interest because of their dual role as both sinks and sources. Most forests are net sinks for CO2 but others, such as drained forests, may be significant sources of both CO2 and N20. Consequently, it is essential to understand the fluxes of GHG between drained forests and the atmosphere in order to obtain accurate estimates of national GHG budgets.

    The findings reported in this thesis and the accompanying papers are based on dark chamber flux measurements of soil GHG fluxes and modelled annual net primary productions in five drained forest sites and two undrained sites situated on organic soil.

    Temporal variations in forest floor CO2, release could be explained, to a large extent, by differencies in temperature and groundwater level. The within-site spatial variation in soil GHG fluxes could only be explained to a very small extent by distance to tree stems. Much of the among-site variations in soil CO2 and CH4 release could be caused by differences in the mean annual groundwater table, while N20 emissions were strongly correlated to the carbon-to-nitrogen ratio of soil organic matter. Most poorly drained forested areas are probably net sinks for GHG as the CO2 uptake by trees more than compensates for the soil GHG emissions. However, the total drained forested area in Sweden was estimated to be a net source of GHG. The CO2 release from decomposition of soil organic matter stored before drainage was estimated to be substantial. Corresponding to 15% of the CO2 release from the consumption of fossil fuels.

  • 94. Aronica, Giuseppe T.
    et al.
    Apel, Heiko
    Di Baldassarre, Giuliano
    UNESCO-IHE Institute for Water Education, Delft, the Netherlands.
    Schumann, Guy J-P.
    HP - Special Issue on Flood Risk and Uncertainty2013In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 27, no 9, 1291- p.Article in journal (Refereed)
  • 95.
    Aronsson, Johanna
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Användning av tredimensionell geologisk modellering i hydrogeologiska utredningar: En fallstudie inför anläggandet av ett akviferlager i Brunkebergsåsen i Stockholm2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Akviferlager är en form av geoenergi där solenergi lagrad i grundvattnet används för att värma och kyla byggnader. Inför anläggandet av ett akviferlager är det viktigt med grundläggande geologiska och hydrogeologiska utredningar för att säkerställa funktion och kapacitet hos akviferlagret, samt minimera eventuell miljöpåverkan. I denna studie utvecklas en tredimensionell geologisk modell för att öka kunskapen om rullstensåsens geologiska uppbyggnad samt bedöma hur geologin kan komma att påverka det planerade akviferlagret. För att undersöka vilken påverkan manuella justeringar och tolkningar av geologin har, togs två geologiska modeller fram för jämförelse. Utifrån de geologiska modellerna uppskattades effektiv hydraulisk konduktivitet för åsen, d.v.s. sammanlagd konduktivitet för hela akviferens mäktighet, samt transporttid mellan akviferlagrets brunnspoler. Studien visar att akviferen består av sammanhängande jordlager med hög hydraulisk konduktivitet. Beroende på tolkningar och justeringar i modelleringsprocessen visar de två olika modellerna på skillnader vad gäller jordlagrens utbredning och mäktighet. Detta medför skillnader i effektiv hydraulisk konduktivitet mellan modellerna, vilket resulterar i relativt stora skillnader vad gäller transporttider mellan brunnspolerna. Tredimensionella geologiska modeller bedöms bidra till förbättrade hydrogeologiska utredningar då det är ett enkelt och effektivt sätt att bygga upp ett områdes geologi för översikt, tolkning och vidare studier i form av exempelvis grundvattenmodellering.

  • 96.
    Aronsson, Johanna
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Saltvattenpåverkan i enskilda brunnar i kustnära områden: En undersökning av grundvattenförhållandena och riskerna för saltvattenpåverkan i S:t Annas skärgård, Östergötland2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Coastal areas are popular for housing, both for permanent living and holiday houses. At the same time, thin sediments and small storage capacity in the bedrock makes the ground water resources limited. The limited ground water resources combined with too large withdrawals of ground water makes salt water intrusion a problem in many coastal areas. This study examine the risk of salt water intrusion in drinking water supplying wells on the island Södra Finnö in S:t Anna archipelago, Östergötland, Sweden. A calculation of the relation between ground water recharge and withdrawal is obtained to analyze the ground water balance in the area. To investigate the thickness of the freshwater in the aquifer, the Ghyben-Herzberg principle is used, based on measurements of ground water levels in the area. The study also includes a GIS-analyze to investigate the risk of salt water intrusion for specific wells, and water samples analyzed for conductivity and sodium. The results show a positive ground water balance, which indicate the area is not to be seen as a risk area for salt water intrusion. However, the GIS-analyze and the water samples shows that some specific wells are in risk of, or has already been effected from, salt water intrusion. 

  • 97.
    Ashkriz, Elnaz
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Regional Sources of Precipitation in the Ethiopian Highlands2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this essay is to investigate the origin of the large amount of precipitation that is present in the northern Ethiopian Highlands. With Moisture transport into the Ethiopian Highlands by Ellen Viste and Asgeir Sorteberg as a base, this essays intents to compare the same data but by focusing on a much smaller time scale. This frame was chosen to see if the data would deviate (i.e. a small and specific time scale versus a large and general time scale). Whilst the investigation by Viste and Sorteberg focuses on the two most rain rich months, July and August during 1998-2008, this essay focuses on only July during 2008.

                          To investigate where the precipitation originates from, this essay has analyzed different meteorological parameters such as horizontal and vertical winds at different altitudes and the moisture content of these winds.

                          This essay has like Viste’s and Sorteberg’s paper used ERA-Interim data as a basis. However the course of action has differed. This essay has made conclusions by visually drawing conclusions by studying the data images while Viste and Asgeir have drawn their conclusions by backtracking the wind to its origin.

                          This investigations results showed that great amounts of moisture were transported into the highlands from the south-west, and to some extent also from the north. While the moisture transport from the south-west was large due to the level of moist in the air, these winds where fairly small and at low altitudes. The winds from the north were visible at higher altitudes and were stronger, however they carried much less water vapor. However, exactly how much each of these winds actually contributed to producing rain is more difficult to say.

                          The results from Viste and Asgeir (2011) showed that the amount of moist that was transported into the highlands were about 46 percent more from the north compared to from the south. The contribution to moisture release within the area was however almost equally great from north and south.

                          Both investigations thus showed that the largest amount of moist was transported from the south and north. What this study did however not address was how large amount of the entire moist that had contributed to rain.

                          One anomaly of large amounts of precipitation was registered on the 20th of July 2008. This study looked closer into this which showed that large winds were registered this date as well as an upwind cell. One can presume that these winds carried large amounts of moisture, which previous results has shown, and that this might be an explanation to the large amount of precipitation that was measured on the 20th of July.

  • 98.
    Ask, Jenny
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Karlsson, Jan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Jansson, Mats
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Net ecosystem production in clear-water and brown-water lakes2012In: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 26, GB1017- p.Article in journal (Refereed)
    Abstract [en]

    We studied 15 lakes in northern Sweden with respect to primary production and respiration in benthic and pelagic habitats. The lakes were characterized by different concentrations of colored dissolved organic carbon (DOC) of terrestrial origin, forming a gradient ranging from clear-water to brown-water lakes. Primary production decreased and respiration increased on a whole-lake scale along the gradient of increasing DOC. Thus, the lakes became more net heterotrophic, i.e., had lower net ecosystem production (NEP = gross primary production - community respiration), with increasing terrestrial DOC and this change coincided with increasing partial pressure of carbon dioxide (pCO(2)) in the surface waters. The single most important process for the increasing net heterotrophy along the DOC gradient was pelagic respiration of terrestrial organic carbon. In spite of high metabolic activity in the benthic habitat, benthic primary production and benthic respiration decreased simultaneously with increasing DOC, showing that the benthic habitat was in metabolic balance throughout the gradient. Therefore, the net heterotrophic states of the lakes depended on the terrestrial DOC export to lakes and the concomitant respiration of terrestrial organic carbon in the pelagic habitat.

  • 99. ASKNE, J
    et al.
    LEPPARANTA, M
    Thompson, Thomas
    SMHI.
    THE BOTHNIAN EXPERIMENT IN PREPARATION FOR ERS-1, 1988 (BEPERS-88) - AN OVERVIEW1992In: International Journal of Remote Sensing, ISSN 0143-1161, E-ISSN 1366-5901, Vol. 13, no 13, 2377-2398 p.Article in journal (Refereed)
    Abstract [en]

    BEPERS-88 was an extensive field campaign on the use of Synthetic Aperture Radar (SAR) in sea ice remote sensing in the Baltic Sea. This experiment was performed in order to study the possibilities of using the ERS-1 satellite SAR (and radar altimeter) in connection with the brackish ice in the Baltic Sea. The Canada Centre for Remote Sensing CV-580 C/X-band SAR was flown and an extensive validation programme was carried out. The data have been used for SAR image analysis, backscatter investigations, geophysical validation of SAR over sea ice, and evaluation of the potentials of SAR in operational ice information services. The results indicate that SAR can be used to discriminate between ice and open water, classify ice types into three categories, quantify ice ridging intensity, and determine the ice drift. As an operational tool SAR is expected to be an excellent complement to NOAA imagery and ground truth.

  • 100.
    Attermeyer, Katrin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany.
    Grossart, Hans-Peter
    Leibniz-Institute of Freshwater Ecology and InlandFisheries, Experimental Limnology, Germany; Institute for Biochemistry and Biology, Potsdam University, Germany.
    Flury, Sabine
    Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany; Faculty of Science, University of Geneva, Switzerland.
    Premke, Katrin
    Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Germany; Leibniz Centre for Agricultural Landscape Research (ZALF), Institute for Landscape Biogeochemistry, Germany.
    Bacterial processes and biogeochemical changes in the water body of kettle holes: mainly driven by autochthonous organic matter?2017In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055Article in journal (Refereed)
    Abstract [en]

    Kettle holes are small inland waters formed from glacially-created depressions often situated in agricultural landscapes. Due to their high perimeter-to-area ratio facilitating a high aquatic-terrestrial coupling, kettle holes can accumulate high concentrations of organic carbon and nutrients, fueling microbial activities and turnover rates. Thus, they represent hotspots of carbon turnover in the landscape, but their bacterial activities and controlling factors have not been well investigated. Therefore, we aimed to assess the relative importance of various environmental factors on bacterial and biogeochemical processes in the water column of kettle holes and to disentangle their variations. In the water body of ten kettle holes in north-eastern Germany, we measured several physico-chemical and biological parameters such as carbon quantity and quality, as well as bacterial protein production (BP) and community respiration (CR) in spring, early summer and autumn 2014. Particulate organic matter served as an indicator of autochthonous production and represented an important parameter to explain variations in BP and CR. This notion is supported by qualitative absorbance indices of dissolved molecules in water samples and C:N ratios of the sediments, which demonstrate high fractions of autochthonous organic matter (OM) in the studied kettle holes. In contrast, dissolved chemical parameters were less important for bacterial activities although they revealed strong differences throughout the growing season. Pelagic bacterial activities and dynamics might thus be regulated by autochthonous OM in kettle holes implying a control of important biogeochemical processes by internal primary production rather than facilitated exchange with the terrestrial surrounding due to a high perimeter-to-area ratio.

1234567 51 - 100 of 2086
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf