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  • 101.
    Amvrosiadi, Nino
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    The value of experimental data and modelling for exploration of hydrological functioning: The case of a till hillslope2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Successfully modeling one system response (e.g. hydrograph or solute transport) sometimes gives the false sense of well-characterizing the modeled system. This is partly because of the well-known equifinality issue; during the calibration process multiple parameter combinations can produce similarly good results. One step forward towards a better-defined system is using measured (at relevant scale) values for the model parameters, as well as using multiple conditions to constrain the model.

    But when not enough, or relevant, field measurements are available, virtual experiments (VE’s) can be used as a supplementary method to model calibration. The advantage of VE’s over model calibration is that they can also be used to explore assumptions both on the system hydrological processes, and on the model structure.

    One goal of this study was to utilize both field measurements and models for better characterization of the S-transect hillslope, located in Västrabäcken catchment, Northern Sweden. This included (a) characteristics in space: system vertical boundaries, hydraulic parameters, pore water velocity distribution, spatial correlation of flowpaths, soil water retention properties; (b) characteristic of system’s dynamic behavior: storage – discharge relationship, transit time distribution, turnover time; and (c) outputs’ sensitivity to external forcing, and to small scale structure assumptions. The second goal was to comment on the value of field measurements and virtual experiments for extracting information about the studied system.

    An intensely monitored study hillslope was chosen for this work. Although the hillslope has already been the subject of multiple field and modelling studies, there are still open questions regarding the characteristics listed above. The models used were the Vertical Equilibrium Model (VEM), and the Multiple Interacting Pathways (MIPs) model.

    It was found that the hillslope was well connected; from the near-stream areas up to the water divide the storage – discharge relationship could be described as an exponential function. Also, the dynamic storage (which controls the hydrograph dynamics) was much smaller comparing to the total hillslope storage. The unsaturated soil storage was found to be more sensitive to water table positions than vertical flux magnitude. The dynamic condition of external forcing (precipitation and evapotranspiration) affected the transit time distribution (TTD) shape. And, opposite to expectations, TTD was not sensitive to micro-scale structural assumptions tested here.

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  • 102.
    Amvrosiadi, Nino
    Uppsala University, Sweden.
    The value of experimental data and modelling for exploration of hydrological functioning: The case of a till hillslope2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Successfully modeling one system response (e.g. hydrograph or solute transport) sometimes gives the false sense of well-characterizing the modeled system. This is partly because of the well-known equifinality issue; during the calibration process multiple parameter combinations can produce similarly good results. One step forward towards a better-defined system is using measured (at relevant scale) values for the model parameters, as well as using multiple conditions to constrain the model. But when not enough, or relevant, field measurements are available, virtual experiments (VE’s) can be used as a supplementary method to model calibration. The advantage of VE’s over model calibration is that they can also be used to explore assumptions both on the system hydrological processes, and on the model structure. One goal of this study was to utilize both field measurements and models for better characterization of the S-transect hillslope, located in Västrabäcken catchment, Northern Sweden. This included (a) characteristics in space: system vertical boundaries, hydraulic parameters, pore water velocity distribution, spatial correlation of flowpaths, soil water retention properties; (b) characteristic of system’s dynamic behavior: storage – discharge relationship, transit time distribution, turnover time; and (c) outputs’ sensitivity to external forcing, and to small scale structure assumptions. The second goal was to comment on the value of field measurements and virtual experiments for extracting information about the studied system. An intensely monitored study hillslope was chosen for this work. Although the hillslope has already been the subject of multiple field and modelling studies, there are still open questions regarding the characteristics listed above. The models used were the Vertical Equilibrium Model (VEM), and the Multiple Interacting Pathways (MIPs) model. It was found that the hillslope was well connected; from the near-stream areas up to the water divide the storage – discharge relationship could be described as an exponential function. Also, the dynamic storage (which controls the hydrograph dynamics) was much smaller comparing to the total hillslope storage. The unsaturated soil storage was found to be more sensitive to water table positions than vertical flux magnitude. The dynamic condition of external forcing (precipitation and evapotranspiration) affected the transit time distribution (TTD) shape. And, opposite to expectations, TTD was not sensitive to micro-scale structural assumptions tested here.

  • 103.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Beven, Keith
    Bishop, Kevin
    Laudon, Hjalmar
    Seibert, Jan
    Value of virtual experiments for a hillslope scale system understandingManuscript (preprint) (Other academic)
  • 104.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Beven, Keith
    Bishop, Kevin
    Seibert, Jan
    Water age dependence on vertical flux assumptionsManuscript (preprint) (Other academic)
  • 105.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Sweden.
    Bishop, K.
    Seibert, J.
    Soil moisture storage estimation based on steady vertical fluxes under equilibrium2017In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 553, p. 798-804Article in journal (Refereed)
    Abstract [en]

    Soil moisture is an important variable for hillslope and catchment hydrology. There are various computational methods to estimate soil moisture and their complexity varies greatly: from one box with vertically constant volumetric soil water content to fully saturated-unsaturated coupled physically-based models. Different complexity levels are applicable depending on the simulation scale, computational time limitations, input data and knowledge about the parameters. The Vertical Equilibrium Model (VEM) is a simple approach to estimate the catchment-wide soil water storage at a daily time-scale on the basis of water table level observations, soil properties and an assumption of hydrological equilibrium without vertical fluxes above the water table. In this study VEM was extended by considering vertical fluxes, which allows conditions with evaporation and infiltration to be represented. The aim was to test the hypothesis that the simulated volumetric soil water content significantly depends on vertical fluxes. The water content difference between the no-flux, equilibrium approach and the new constant-flux approach greatly depended on the soil textural class, ranging between ∼1% for silty clay and ∼44% for sand at an evapotranspiration rate of 5 mm·d−1. The two approaches gave a mean volumetric soil water content difference of ∼1 mm for two case studies (sandy loam and organic rich soils). The results showed that for many soil types the differences in estimated storage between the no-flux and the constant flux approaches were relatively small.

  • 106.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Bishop, Kevin
    Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.
    Seibert, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. Univ Zurich, Dept Geog, Zurich, Switzerland.
    Soil moisture storage estimation based on steady vertical fluxes under equilibrium2017In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 553, p. 798-804Article in journal (Refereed)
    Abstract [en]

    Soil moisture is an important variable for hillslope and catchment hydrology. There are various computational methods to estimate soil moisture and their complexity varies greatly: from one box with vertically constant volumetric soil water content to fully saturated-unsaturated coupled physically-based models. Different complexity levels are applicable depending on the simulation scale, computational time limitations, input data and knowledge about the parameters. The Vertical Equilibrium Model (VEM) is a simple approach to estimate the catchment-wide soil water storage at a daily time-scale on the basis of water table level observations, soil properties and an assumption of hydrological equilibrium without vertical fluxes above the water table. In this study VEM was extended by considering vertical fluxes, which allows conditions with evaporation and infiltration to be represented. The aim was to test the hypothesis that the simulated volumetric soil water content significantly depends on vertical fluxes. The water content difference between the no-flux, equilibrium approach and the new constant-flux approach greatly depended on the soil textural class, ranging between similar to 1% for silty clay and similar to 44% for sand at an evapotranspiration rate of 5 mm.d(-1). The two approaches gave a mean volumetric soil water content difference of 1 mm for two case studies (sandy loam and organic rich soils). The results showed that for many soil types the differences in estimated storage between the no-flux and the constant flux approaches were relatively small.

  • 107.
    Amvrosiadi, Nino
    et al.
    Uppsala University, Sweden.
    Seibert, J.
    Grabs, T.
    Bishop, K.
    Water storage dynamics in a till hillslope: the foundation for modeling flows and turnover times2017In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 31, no 1, p. 4-14Article in journal (Refereed)
    Abstract [en]

    Studies on hydrology, biogeochemistry, or mineral weathering often rely on assumptions about flow paths, water storage dynamics, and transit times. Testing these assumptions requires detailed hydrometric data that are usually unavailable at the catchment scale. Hillslope studies provide an alternative for obtaining a better understanding, but even on such well-defined and delimited scales, it is rare to have a comprehensive set of hydrometric observations from the water divide down to the stream that can constrain efforts to quantify water storage, movement, and turnover time. Here, we quantified water storage with daily resolution in a hillslope during the course of almost an entire year using hydrological measurements at the study site and an extended version of the vertical equilibrium model. We used an exponential function to simulate the relationship between hillslope discharge and water table; this was used to derive transmissivity profiles along the hillslope and map mean pore water velocities in the saturated zone. Based on the transmissivity profiles, the soil layer transmitting 99% of lateral flow to the stream had a depth that ranged from 8.9 m at the water divide to under 1 m closer to the stream. During the study period, the total storage of this layer varied from 1189 to 1485 mm, resulting in a turnover time of 2172 days. From the pore water velocities, we mapped the time it would take a water particle situated at any point of the saturated zone anywhere along the hillslope to exit as runoff. Our calculations point to the strengths as well as limitations of simple hydrometric data for inferring hydrological properties and water travel times in the subsurface. 

  • 108.
    Anamaghi, Sara
    et al.
    Faculty of Civil Engineering, K. N. Toosi University of Technology, Tehran, Iran.
    Behboudian, Massoud
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Water and Environmental Engineering. School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran.
    Mahjouri, Najmeh
    Faculty of Civil Engineering, K. N. Toosi University of Technology, Tehran, Iran.
    Kerachian, Reza
    School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran.
    A resilience-based framework for evaluating the carrying capacity of water and environmental resources under the climate change2023In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 902, article id 165986Article in journal (Refereed)
    Abstract [en]

    This paper proposes a new framework for evaluating water and environmental resources carrying capacity (WERCC) based on the concept of resilience under uncertainty. First, several quantitative and qualitative criteria based on the seven principles of resilience and the Pressure-Support-State (PSS) framework are defined to incorporate the positive and negative impacts of human interventions and natural factors on water resources and the environment. The resilience principles include redundancy and diversity, managing connectivity, managing slow variables and their feedbacks, fostering complex adaptive system (CAS) thinking, encouraging learning, broadening participation, and promoting polycentric governance. After evaluating the values of the criteria and sub-criteria using a two-point evidential reasoning (TPER) approach and considering the existing uncertainties, the monthly time series of WERCC with uncertainty bands are calculated. The proposed methodology is then used to evaluate the WERCC in the Zarrinehrud river basin in Iran for a given historical period (1991–2012), and the period of 2020 to 2049 under different climate change scenarios. The results of this analysis demonstrate the inadequacy of the WERCC during the historical period and indicate that the continuation of the existing trend (base scenario, MSC0) will cause many environmental issues. Hence, several water and environmental resources management (WERM) scenarios are proposed to enhance the WERCC. These scenarios are evaluated using a multi-agent-multi-criteria decision-making method to identify the preferable WERM scenario (MSC12356). This scenario, which encompasses various projects (e.g., development and enhancement of water transfer networks and upgrading cultivation methods), improves the average value of the WERCC by 26 %. The results of the proposed methodology are compared with those of a traditional decision-making method, which considers three criteria of average WERCC, the pressure-support index, and the implementation cost. The results demonstrate that the multi-agent-multi-criteria decision-making approach provides a more cost-effective management scenario, with 30 % less cost, leading to only 3 % less carrying capacity.

  • 109. Anastasiadis, Stavros
    et al.
    Boglis, Argiris
    Pechlivanidis, Ilias
    SMHI, Research Department, Hydrology.
    Lekkas, Demetris F.
    Baltas, Evaggelos
    APPLICATION OF GIS BASED CLARK'S UNIT HYDROGRAPH AND TRANSFER FUNCTION MODEL TO DESCRIBE RUNOFF RESPONSE IN A SMALL CATCHMENT, CASE STUDY: LYKOREMMA RIVER, GREECE2013In: Fresenius Environmental Bulletin, ISSN 1018-4619, E-ISSN 1610-2304, Vol. 22, no 7B, p. 2152-2158Article in journal (Refereed)
    Abstract [en]

    The hydrologic community has recently focused substantial attention on ungauged or poorly gauged catchments, since hydrological prediction under these conditions is highly uncertain, but represents the majority of practical applications. Catchments in Greece are usually ungauged, due to resource constrains, whilst in gauged areas the period of record is often short for safe estimation of highly parameterised hydrological models. This paper is driven by the Prediction in Ungauged Basins initiative aiming to estimate catchment responses using readily available data, i.e. topographical, soil and land use information. The parsimonious rainfall-runoff model developed in a Geographical Information System (GIS) environment is based on the Clark's synthetic unit hydrograph technique to estimate the hydrological response. The method requires estimation of the time of concentration (based on the curve number), the storage attenuation coefficient and the time area histogram of the catchment. The models further compared with a data-based modelling approach using a Transfer Function and the simulated streamflow is analysed to investigate similarities as well as to better understand possible extensions of the resulting unit hydrograph. A case study using 10-minute observed data from the 15 km(2) Lykorema catchment, Attica, Greece, highlights the potential of the GIS-based model to predict, at least, the dynamic characteristics of the runoff response in ungauged or poorly gauged catchments.

  • 110.
    Anderberg, Hilda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Olsson, Sofia
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Bjerklund, Frida
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Larsson, Therese
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Junegard, Frida
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Risker vid översvämning och åtgärdsförslag för MSB:s skola i Revinge2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    På skolan i Revinge utbildar Myndigheten för samhällsskydd och beredskap (MSB) personer inom områdena skydd mot olyckor och krisberedskap. Vid ett flertal tillfällen har Kävlingeån översvämmat skolområdet vilket resulterat i att verksamheten blivit stillastående i flera veckor. Grundvattennivån ligger nära markytan på skolområdet och platsen är därför extra känslig för översvämningar både från ån och extrem nederbörd.

    För att kunna minimera konsekvenserna vid en översvämning identifierades olika objekt, byggnader och områden, som i rapporten är benämnda som skyddsobjekt, som drabbas mest vid översvämning. För att ta hänsyn till att framtida väderförhållanden kan bli mer extrema undersöktes två klimatanpassade scenarier, höga flöden från ån och extrem nederbörd. Olika åtgärder mot översvämningar som potentiellt kan passa skolområdet togs fram och viktades utefter kostnader, lagar och skyddskapacitet.

    Skyddsobjekten som togs fram är skolans övningytor, kontorsbyggnader, hus med källare, spillvattenbrunnar, områden som kan sprida miljöfarliga ämnen, elskåp samt fordonshall/förråd. Skyddsobjekten viktades utefter översvämningskonsekvensernas direkta kostnader, hinder för utbildning samt fara för människor och natur, i relation till hur sannolikt det är att objekten blir översvämmade. Övningsytor, spillvattenbrunnar och områden som kan sprida miljöfarliga ämnen fick högsta prioritet.

    De åtgärder mot översvämning som undersöktes var gröna tak, regnmagasin, regnbäddar, träd, kontrollerad översvämningsyta och permanent vall. De fyra förstnämnda bedömdes billiga och lagligt sett icke komplicerade i relation till permanent vall och kontrollerad översvämningsyta. En summering av vilka skyddsobjekt varje åtgärd skyddar lades till. En effektivitetsfaktor togs fram i relation till vilka scenarier åtgärderna verkar mot och i vilken grad de kan motverka ett scenario på egen hand. Detta gav värderingen, från högst till lägst, permanent vall, träd, översvämningsyta, regnmagasin, regnbäddar och gröna tak.

    Som ytterligare åtgärder rekommenderas det att utesluta användning av källare helt och bestämmelser kring nybyggnation bör tas i relation till var det finns störst risk för översvämning på området. Ett förslag till MSB finns om att ta kontakt med Kävlingeå-projektet som arbetar med att utöka andelen våtmarker utmed Kävlingeån, där ett av målen för projektet är att motverka översvämningar. Arbetet drivs av Kävlingeåns Vattenråd, vilka också kan ha mer information kring hur regleringen av Vombsjön kan påverka risken för översvämning på skolområdet. 

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  • 111.
    Andersen, Casper W.
    et al.
    Ecole Polytech Fed Lausanne, Switzerland; Ecole Polytech Fed Lausanne, Switzerland.
    Armiento, Rickard
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Blokhin, Evgeny
    Tilde Mat Informat, Germany; Mat Platform Data Sci, Estonia.
    Conduit, Gareth J.
    Condensed Matter Theory Grp, England.
    Dwaraknath, Shyam
    Lawrence Berkeley Natl Lab, CA 94720 USA.
    Evans, Matthew L.
    Condensed Matter Theory Grp, England; UCLouvain, Belgium.
    Fekete, Adam
    UCLouvain, Belgium; Kings Coll London, England.
    Gopakumar, Abhijith
    Northwestern Univ, IL 60208 USA.
    Grazulis, Saulius
    Vilnius Univ, Lithuania; Vilnius Univ, Lithuania.
    Merkys, Andrius
    Vilnius Univ, Lithuania.
    Mohamed, Fawzi
    Fritz Haber Inst Max Planck Gesell, Germany.
    Oses, Corey
    Duke Univ, NC 27708 USA; Duke Univ, NC 27708 USA.
    Pizzi, Giovanni
    Ecole Polytech Fed Lausanne, Switzerland; Ecole Polytech Fed Lausanne, Switzerland.
    Rignanese, Gian-Marco
    UCLouvain, Belgium.
    Scheidgen, Markus
    Fritz Haber Inst Max Planck Gesell, Germany; Humboldt Univ, Germany; Humboldt Univ, Germany.
    Talirz, Leopold
    Ecole Polytech Fed Lausanne, Switzerland; Ecole Polytech Fed Lausanne, Switzerland; Ecole Polytech Fed Lausanne, Switzerland.
    Toher, Cormac
    Duke Univ, NC 27708 USA; Duke Univ, NC 27708 USA.
    Winston, Donald
    Lawrence Berkeley Natl Lab, CA 94720 USA.
    Aversa, Rossella
    CNR, Italy; Karlsruhe Inst Technol KIT, Germany.
    Choudhary, Kamal
    Natl Inst Stand & Technol, MD 20899 USA.
    Colinet, Pauline
    Duke Univ, NC 27708 USA; Duke Univ, NC 27708 USA.
    Curtarolo, Stefano
    Duke Univ, NC 27708 USA; Duke Univ, NC 27708 USA.
    Di Stefano, Davide
    Ansys, England.
    Draxl, Claudia
    Humboldt Univ, Germany; Humboldt Univ, Germany.
    Er, Suleyman
    Dutch Inst Fundamental Energy Res DIFFER, Netherlands.
    Esters, Marco
    Duke Univ, NC 27708 USA; Duke Univ, NC 27708 USA.
    Fornari, Marco
    Duke Univ, NC 27708 USA; Cent Michigan Univ, MI 48859 USA.
    Giantomassi, Matteo
    UCLouvain, Belgium.
    Govoni, Marco
    Argonne Natl Lab, IL 60439 USA.
    Hautier, Geoffroy
    UCLouvain, Belgium; Dartmouth Coll, NH 03755 USA.
    Hegde, Vinay
    Northwestern Univ, IL 60208 USA.
    Horton, Matthew K.
    Lawrence Berkeley Natl Lab, CA 94720 USA.
    Huck, Patrick
    Lawrence Berkeley Natl Lab, CA 94720 USA.
    Huhs, Georg
    Humboldt Univ, Germany; Humboldt Univ, Germany.
    Hummelshoj, Jens
    Toyota Res Inst TRI, CA 94022 USA.
    Kariryaa, Ankit
    Univ Copenhagen, Denmark.
    Kozinsky, Boris
    Harvard Univ, MA 02138 USA; Robert Bosch LLC, MA 02142 USA.
    Kumbhar, Snehal
    Ecole Polytech Fed Lausanne, Switzerland; Ecole Polytech Fed Lausanne, Switzerland.
    Liu, Mohan
    Northwestern Univ, IL 60208 USA.
    Marzari, Nicola
    Ecole Polytech Fed Lausanne, Switzerland; Ecole Polytech Fed Lausanne, Switzerland.
    Morris, Andrew J.
    Univ Birmingham, England.
    Mostofi, Arash A.
    Imperial Coll London, England; Imperial Coll London, England; Imperial Coll London, England.
    Persson, Kristin A.
    Lawrence Berkeley Natl Lab, CA 94720 USA; Univ Calif Berkeley, CA 94720 USA.
    Petretto, Guido
    UCLouvain, Belgium.
    Purcell, Thomas
    Fritz Haber Inst Max Planck Gesell, Germany.
    Ricci, Francesco
    UCLouvain, Belgium.
    Rose, Frisco
    Duke Univ, NC 27708 USA; Duke Univ, NC 27708 USA.
    Scheffler, Matthias
    Fritz Haber Inst Max Planck Gesell, Germany.
    Speckhard, Daniel
    Fritz Haber Inst Max Planck Gesell, Germany; Humboldt Univ, Germany; Humboldt Univ, Germany.
    Uhrin, Martin
    Ecole Polytech Fed Lausanne, Switzerland; Ecole Polytech Fed Lausanne, Switzerland.
    Vaitkus, Antanas
    Vilnius Univ, Lithuania.
    Villars, Pierre
    Mat Platform Data Sci, Estonia.
    Waroquiers, David
    UCLouvain, Belgium.
    Wolverton, Chris
    Northwestern Univ, IL 60208 USA.
    Wu, Michael
    Lawrence Berkeley Natl Lab, CA 94720 USA.
    Yang, Xiaoyu
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    OPTIMADE, an API for exchanging materials data2021In: Scientific Data, E-ISSN 2052-4463, Vol. 8, no 1, article id 217Article in journal (Refereed)
    Abstract [en]

    The Open Databases Integration for Materials Design (OPTIMADE) consortium has designed a universal application programming interface (API) to make materials databases accessible and interoperable. We outline the first stable release of the specification, v1.0, which is already supported by many leading databases and several software packages. We illustrate the advantages of the OPTIMADE API through worked examples on each of the public materials databases that support the full API specification.

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  • 112. Andersen, Jesper H.
    et al.
    Axe, Philip
    SMHI, Research Department, Oceanography.
    Backer, Hermanni
    Carstensen, Jacob
    Claussen, Ulrich
    Fleming-Lehtinen, Vivi
    Jarvinen, Marko
    Kaartokallio, Hermanni
    Knuuttila, Seppo
    Korpinen, Samuli
    Kubiliute, Aiste
    Laamanen, Maria
    Lysiak-Pastuszak, Elzbieta
    Martin, Georg
    Murray, Ciaran
    Mohlenberg, Flemming
    Nausch, Guenther
    Norkko, Alf
    Villnas, Anna
    Getting the measure of eutrophication in the Baltic Sea: towards improved assessment principles and methods2011In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 106, no 2, p. 137-156Article in journal (Refereed)
    Abstract [en]

    The eutrophication status of the entire Baltic Sea is classified using a multi-metric indicator-based assessment tool. A total of 189 areas are assessed using indicators where information on reference conditions (RefCon), and acceptable deviation (AcDev) from reference condition could be combined with national monitoring data from the period 2001-2006. Most areas (176) are classified as 'affected by eutrophication' and only two open water areas and 11 coastal areas are classified as 'unaffected by eutrophication'. The classification is made by application of the recently developed HELCOM Eutrophication Assessment Tool (HEAT), which is described in this paper. The use of harmonized assessment principles and the HEAT tool allows for direct comparisons between different parts of the Baltic Sea despite variations in monitoring activities. The impaired status of 176 areas is directly related to nutrient enrichment and elevated loads from upstream catchments. Baltic Sea States have implemented nutrient management strategies since years which have reduced nutrient inputs. However, eutrophication is still a major problem for large parts of the Baltic Sea. The 2007 Baltic Sea Action Plan is projected to further reduce nutrient inputs aiming for a Baltic Sea unaffected by eutrophication by 2021.

  • 113. Andersen, Jesper H.
    et al.
    Murray, Ciaran
    Kaartokallio, Hermanni
    Axe, Philip
    SMHI, Research Department, Oceanography.
    Molvaer, Jarle
    A simple method for confidence rating of eutrophication status classifications2010In: Marine Pollution Bulletin, ISSN 0025-326X, E-ISSN 1879-3363, Vol. 60, no 6, p. 919-924Article in journal (Refereed)
    Abstract [en]

    We report the development of a methodology for assessing confidence in ecological status classifications. The method presented here can be considered as a secondary assessment, supporting the primary assessment of eutrophication or ecological status. The confidence assessment is based on scoring the quality of the indicators on which the primary assessment is made. This represents a first step towards linking status classification with information regarding their accuracy and precision. Applied to an existing data set used for assessment of eutrophication status of the Baltic Sea (including the Kattegat and Danish Straits) we demonstrate that confidence in the assessment is Good or High in 149 out of 189 areas assessed (79%). Contrary to our expectations, assessments of the open parts of the Baltic Sea have a higher confidence than assessments of coastal waters. We also find that in open waters of the Baltic Sea, some biological indicators have a higher confidence than indicators representing physical-chemical conditions. In coastal waters, phytoplankton, submerged aquatic vegetation and indicators of physical-chemical conditions have a higher confidence than indicators of the quality of benthic invertebrate communities. Our analyses also show that the perceived weaknesses of eutrophication assessments are due more to Low confidence in reference conditions and acceptable deviations, rather than in the monitoring data. (C) 2010 Elsevier Ltd. All rights reserved.

  • 114. Anderson., D. M
    et al.
    Karlson, Bengt
    SMHI, Research Department, Oceanography.
    Preservatives and methods for algal cell enumeration2017In: Harmful Algal Blooms (HABs) and Desalination: A Guide to Impacts, Monitoring and Management / [ed] Anderson D. M., S. F. E. Boerlage, M. B. Dixon, Paris: Intergovernmental Oceanographic Commission of UNESCO , 2017, p. 509-517Chapter in book (Refereed)
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  • 115.
    Anderson, Leif G.
    et al.
    Univ Gothenburg, Dept Marine Sci, POB 461, S-40530 Gothenburg, Sweden..
    Björk, Göran
    Univ Gothenburg, Dept Marine Sci, POB 461, S-40530 Gothenburg, Sweden..
    Holby, Ola
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Jutterstrom, Sara
    IVL Swedish Environm Res Inst, Box 530 21, S-40014 Gothenburg, Sweden..
    Morth, Carl Magnus
    Stockholm Univ, Dept Geol Sci, S-10691 Stockholm, Sweden..
    O'Regan, Matt
    Stockholm Univ, Dept Geol Sci, S-10691 Stockholm, Sweden..
    Pearce, Christof
    Stockholm Univ, Dept Geol Sci, S-10691 Stockholm, Sweden.;Aarhus Univ, Dept Geosci, Aarhus, Denmark..
    Semiletov, Igor
    Univ Alaska Fairbanks, Int Arctic Res Ctr, Fairbanks, AK 99775 USA.;Russian Acad Sci, Far Eastern Branch, Pacific Oceanol Inst, Vladivostok 690041, Russia.;Natl Res Tomsk Polytech Univ, Tomsk, Russia..
    Stranne, Christian
    Ctr Coastal & Ocean Mapping, Joint Hydrog Ctr, Durham, NH 03824 USA..
    Stoven, Tim
    GEOMAR, Helmholtz Ctr Ocean Res Kiel, Kiel, Germany..
    Tanhua, Toste
    GEOMAR, Helmholtz Ctr Ocean Res Kiel, Kiel, Germany..
    Ulfsbo, Adam
    Univ Gothenburg, Dept Marine Sci, POB 461, S-40530 Gothenburg, Sweden.;Duke Univ, Nicholas Sch Environm, Div Earth & Ocean Sci, Durham, NC 27704 USA..
    Jakobsson, Martin
    Stockholm Univ, Dept Geol Sci, S-10691 Stockholm, Sweden..
    Shelf-Basin interaction along the East Siberian Sea2017In: Ocean Science, ISSN 1812-0784, E-ISSN 1812-0792, Vol. 13, no 2, p. 349-363Article in journal (Refereed)
    Abstract [en]

    Extensive biogeochemical transformation of organic matter takes place in the shallow continental shelf seas of Siberia. This, in combination with brine production from sea-ice formation, results in cold bottom waters with relatively high salinity and nutrient concentrations, as well as low oxygen and pH levels. Data from the SWERUS-C3 expedition with icebreaker Oden, from July to September 2014, show the distribution of such nutrient-rich, cold bottom waters along the continental margin from about 140 to 180 degrees E. The water with maximum nutrient concentration, classically named the upper halocline, is absent over the Lomonosov Ridge at 140 degrees E, while it appears in the Makarov Basin at 150 degrees E and intensifies further eastwards. At the intercept between the Mendeleev Ridge and the East Siberian continental shelf slope, the nutrient maximum is still intense, but distributed across a larger depth interval. The nutrient-rich water is found here at salinities of up to similar to 34.5, i.e. in the water classically named lower halocline. East of 170 degrees E transient tracers show significantly less ventilated waters below about 150 m water depth. This likely results from a local isolation of waters over the Chukchi Abyssal Plain as the boundary current from the west is steered away from this area by the bathymetry of the Mendeleev Ridge. The water with salinities of similar to 34.5 has high nutrients and low oxygen concentrations as well as low pH, typically indicating decay of organic matter. A deficit in nitrate relative to phosphate suggests that this process partly occurs under hypoxia. We conclude that the high nutrient water with salinity similar to 34.5 are formed on the shelf slope in the Mendeleev Ridge region from interior basin water that is trapped for enough time to attain its signature through interaction with the sediment.

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  • 116.
    Andersson, Agneta
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Brugel, Sonia
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Paczkowska, Joanna
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Rowe, Owen F.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF). Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, University of Helsinki, Helsinki, Finland.
    Figueroa, Daniela
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Kratzer, S.
    Legrand, C.
    Influence of allochthonous dissolved organic matter on pelagic basal production in a northerly estuary2018In: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 204, p. 225-235Article in journal (Refereed)
    Abstract [en]

    Phytoplankton and heterotrophic bacteria are key groups at the base of aquatic food webs. In estuaries receiving riverine water with a high content of coloured allochthonous dissolved organic matter (ADOM), phytoplankton primary production may be reduced, while bacterial production is favoured. We tested this hypothesis by performing a field study in a northerly estuary receiving nutrient-poor, ADOM-rich riverine water, and analyzing results using multivariate statistics. Throughout the productive season, and especially during the spring river flush, the production and growth rate of heterotrophic bacteria were stimulated by the riverine inflow of dissolved organic carbon (DOC). In contrast, primary production and photosynthetic efficiency (i.e. phytoplankton growth rate) were negatively affected by DOC. Primary production related positively to phosphorus, which is the limiting nutrient in the area. In the upper estuary where DOC concentrations were the highest, the heterotrophic bacterial production constituted almost 100% of the basal production (sum of primary and bacterial production) during spring, while during summer the primary and bacterial production were approximately equal. Our study shows that riverine DOC had a strong negative influence on coastal phytoplankton production, likely due to light attenuation. On the other hand DOC showed a positive influence on bacterial production since it represents a supplementary food source. Thus, in boreal regions where climate change will cause increased river inflow to coastal waters, the balance between phytoplankton and bacterial production is likely to be changed, favouring bacteria. The pelagic food web structure and overall productivity will in turn be altered.

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  • 117. Andersson, Agneta
    et al.
    Grinienė, Evelina
    Berglund, Åsa M. M.
    Brugel, Sonia
    Gorokhova, Elena
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Figueroa, Daniela
    Gallampois, Christine
    Ripszam, Matyas
    Tysklind, Mats
    Microbial food web changes induced by terrestrial organic matter and elevated temperature in the coastal northern Baltic Sea2023In: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 10, article id 1170054Article in journal (Refereed)
    Abstract [en]

    Climate change has been projected to cause increased temperature and amplified inflows of terrestrial organic matter to coastal areas in northern Europe. Consequently, changes at the base of the food web favoring heterotrophic bacteria over phytoplankton are expected, affecting the food web structure. We tested this hypothesis using an outdoor shallow mesocosm system in the northern Baltic Sea in early summer, where the effects of increased temperature (+ 3°C) and terrestrial matter inputs were studied following the system dynamics and conducting grazing experiments. Juvenile perch constituted the highest trophic level in the system, which exerted strong predation on the zooplankton community. Perch subsequently released the microbial food web from heavy grazing by mesozooplankton. Addition of terrestrial matter had a stronger effect on the microbial food web than the temperature increase, because terrestrial organic matter and accompanying nutrients promoted both heterotrophic bacterial production and phytoplankton primary production. Moreover, due to the shallow water column in the experiment, terrestrial matter addition did not reduce the light below the photosynthesis saturation level, and in these conditions, the net-autotrophy was strengthened by terrestrial matter enrichment. In combination with elevated temperature, the terrestrial matter addition effects were intensified, further shifting the size distribution of the microbial food web base from picoplankton to microphytoplankton. These changes up the food web led to increase in the biomass and proportion of large-sized ciliates (>60 µm) and rotifers. Despite the shifts in the microbial food web size structure, grazing experiments suggested that the pathway from picoplankton to nano- and microzooplankton constituted the major energy flow in all treatments. The study implies that the microbial food web compartments in shallow coastal waters will adjust to climate induced increased inputs of terrestrial matter and elevated temperature, and that the major energy path will flow from picoplankton to large-sized ciliates during the summer period.

     

  • 118.
    Andersson, Agneta
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Karlsson, Chatarina
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Hajdu, Susanna
    Stockholms universitet.
    Höglander, Helena
    Stockholms universitet.
    Skjevik, Ann-Turi
    SMHI.
    Pelagial biologi / växtplankton2010In: Havet: om miljötillståndet i svenska havsområden. 2010 / [ed] Kristina Viklund (huvudredaktör) Ulrika Brenner, Annika Tidlund, Marie Svärd, Stockholm: Naturvårdsverket, 2010, p. 32-33Chapter in book (Other academic)
  • 119.
    Andersson, Agneta
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Meier, Markus
    SMHI och Stockholms universitet.
    Hur påverkas Östersjön?2010In: Sverige i nytt klimat: våtvarm utmaning / [ed] Birgitta Johansson, Stockholm: Forskningsrådet Formas, 2010, p. 117-132Chapter in book (Other academic)
  • 120. Andersson, Agneta
    et al.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Ripszam, Matyas
    Rowe, Owen
    Wikner, Johan
    Haglund, Peter
    Eilola, Kari
    SMHI, Research Department, Oceanography.
    Legrand, Catherine
    Figueroa, Daniela
    SMHI, Core Services.
    Paczkowska, Joanna
    Lindehoff, Elin
    Tysklind, Mats
    Elmgren, Ragnar
    Projected future climate change and Baltic Sea ecosystem management2015In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 44, p. S345-S356Article in journal (Refereed)
    Abstract [en]

    Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 degrees C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase similar to 30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes.

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  • 121.
    Andersson, Agneta
    et al.
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF). Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Selstam, Eva
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Hagström, Åke
    Vertical transport of lipid in seawater1993In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 98, no 1-2, p. 149-155Article in journal (Refereed)
    Abstract [en]

    Lipids in seawater act as solvents and transporters of lipophilic organic pollutants. To investigate a possible transport route of lipophilic pollutants, the vertical flux of lipid was quantified during an annual cycle in the northern Baltic Sea. The lipid content in both sedimenting material and different size fractions of seawater was analyzed. During the year, 8 g lipid m-2 sedimented out from the photic zone to the benthic system. The sedimentation of lipid accounted for 300 to 400 % of the average standing stock of pelagic lipid and was concentrated in the spring bloom period (April-June) when 70 % of the total lipid sedimentation occurred. About 30 % of the produced pelagic lipid settled out from the system. In seawater the lipid maximum occurred at the end of the spring bloom, shortly after nutrient depletion, indicating a stress response in the algae. Since lipid sedimentation is concentrated in the spring bloom, removal of lipophilic organic pollutants may be important during this period.

  • 122.
    Andersson, Agneta
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Tamminen, Timo
    Lehtinen, Sirpa
    Jürgens, Klaus
    Labrenz, Matthias
    Viitasalo, Markku
    The pelagic food web2017In: Biological oceanography of the Baltic sea / [ed] Pauline Snoeijs, Hendrik Schubert, Teresa Radziejewska, Dordrecht: Springer Netherlands, 2017, p. 281-332Chapter in book (Refereed)
    Abstract [en]
    1. Environmental drivers and food web structure in the pelagic zone vary from south to north in the Baltic Sea. 
    2. While nitrogen is generally the limiting nutrient for primary production in the Baltic Sea, phosphorus is the limiting nutrient in the Bothnian Bay. 
    3. In the Gulf of Bothnia the food web is to a large extent driven by terrestrial allochthonous material, while autochthonous production dominates in the other parts of the Baltic Sea. 
    4. Changes in bacterioplankton, protist and zooplankton community composition from south to north are mainly driven by salinity. 
    5. Bacteria are crucial constituents of the pelagic food web (microbial loop) and in oxygen-poor and anoxic bottom waters where they mediate element transformations. 
    6. Diatoms and dinoflagellates are the major primary producers in the pelagic zone. Summer blooms of diazotrophic (nitrogen-fixing) filamentous cyanobacteria are typical of the Baltic Sea, especially in the Baltic Sea proper and the Gulf of Finland. 
    7. The mesozooplankton (mainly copepods and cladocerans) channel energy from primary producers and the microbial food web to fish and finally to the top predators in the pelagic system (waterbirds and mammals). 
    8. Herring and sprat populations are affected by the foraging intensity of their main predator (cod), and therefore the environmental conditions that affect cod may also influence mesozooplankton due to food web effects "cascading down the food web". 
    9. Anthropogenic pressures, such as overexploitation of fish stocks, eutrophication, climate change, introduction of non-indigenous species and contamination of top predators by hazardous substances, cause changes in the pelagic food web that may have consequences for the balance and stability of the whole ecosystem.
  • 123.
    Andersson, Agneta
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Wikner, Johan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Klimatförändringar kan leda till mindre fisk i havet2016In: Havet: om miljötillståndet i svenska havsområden. 2015/2016, Göteborg: Havs- och vattenmyndigheten , 2016, p. 25-28Chapter in book (Other academic)
  • 124.
    Andersson, Agneta
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Wikner, Johan
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Pelagisk biologi2004In: Bottniska viken: årsrapport från den marina miljöövervakningen. 2003, Skydd av havsområden gagnar fisken, Hörnefors: Umeå marina forskningscentrum (UMF) , 2004, p. 11-13Chapter in book (Refereed)
  • 125.
    Andersson, Agneta
    et al.
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF). Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Zhao, Li
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Brugel, Sonia
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Figueroa, Daniela
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Huseby, Siv
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Metabarcoding vs Microscopy - comparison of methods to monitor phytoplankton communities2023In: ACS - ES & T Water, E-ISSN 2690-0637, Vol. 3, no 8, p. 2671-2680Article in journal (Other academic)
    Abstract [en]

    Phytoplankton are used worldwide to monitor environmental status in aquatic systems. Long-time series of microscopy-analyzed phytoplankton are available from many monitoring stations. The microscopy-method is however time consuming and has short-comings. DNA metabarcoding has been suggested as an alternative method, but the consistency between different methods need further investigation. We performed a comparative study of microscopy and metabarcoding analyzing micro- and nanophytoplankton. For metabarcoding, 25-1000 ml seawater were filtered, DNA extracted and the 18S and 16S rRNA gene amplicons sequenced. For microscopy, based on the Utermöhl method we evaluated the use of three metrics: abundance, biovolume and carbon biomass. At the genus, species, and unidentified taxa level, metabarcoding generally showed higher taxonomic diversity than microscopy, and diversity was already captured at the lowest filtration volume tested, 25 ml. Metabarcoding and microscopy displayed relatively similar distribution pattern at the group level. The results showed that the relative abundances of the 18S rRNA amplicon at the group level best fitted the microscopy carbon biomass metric. The results are promising for implementing DNA metabarcoding as a complement to microscopy in phytoplankton monitoring, especially if databases would be improved and group level indexes could be applied to classify the environmental state of water bodies.

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  • 126.
    Andersson, Anna
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Ashiq, Muhammad Jamshaid
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Shoeb, Mohammad
    Department of Chemistry, University of Dhaka, Dhaka, Bangladesh.
    Karlsson, Susanne
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Bastviken, David
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Kylin, Henrik
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Research Unit: Environmental Sciences and Management, North-West University, Potchefstroom, South Africa.
    Evaluating gas chromatography with a halogen-specific detector for the determination of disinfection by-products in drinking water2019In: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, p. 7305-7314Article in journal (Refereed)
    Abstract [en]

    The occurrence of disinfection by-products (DBPs) in drinking water has become an issue of concern during the past decades. The DBPs pose health risks and are suspected to cause various cancer forms, be genotoxic and have negative developmental effects. The vast chemical diversity of DBPs makes comprehensive monitoring challenging. Only few of the DBPs are regulated and included in analytical protocols. In this study, a method for simultaneous measurement of 20 DBPs from five different structural classes (both regulated and non-regulated) was investigated and further developed for 11 DBPs using solid phase extraction and gas chromatography coupled with a halogen specific detector (XSD). The XSD was highly selective towards halogenated DBPs, providing chromatograms with little noise. The method allowed detection down to 0.05 µg/L and showed promising results for the simultaneous determination of a range of neutral DBP classes. Compounds from two classes of emerging DBPs, more cytotoxic than the “traditional” regulated DBPs, were successfully determined using this method. However, haloacetic acids (HAAs) should be analyzed separately as some HAA methyl esters may degrade giving false positives of trihalomethanes (THMs). The method was tested on real water samples from two municipal waterworks where the target DBP concentrations were found below the regulatory limits of Sweden.

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    Evaluating gas chromatography with a halogen-specific detectorfor the determination of disinfection by-products in drinking water
  • 127.
    Andersson, Edwin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Gulding, William
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Högvattenföring ochriskbedömning i svensk miljö2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The focus of this paper is on the changing conditions in the hydrological flow of the upper half of Pite älv in Northern Sweden as a consequence of the changes that comes with global warming. This was done by modelling the water flow with the HBV-96 model as its basis which then ran four different scenarios based on predictions for how the climate will have changed by year 2100. The paper also discusses the limitations with this applied method.

    The study found that in the case of dam failure the owner is responsible for the damages, furthermore the owner is recommended to model potential limitations and dangers, but there is no requirement for this. State actors which oversees and keep tabs on all issues regarding water safety exists for every county, though their involvement appear somewhat limited and does not extend to close monitoring of the dams.

    The study found a decrease in the volume of spring floods due to a decrease in snow storage because of increasing temperatures. Furthermore, the increase in mean temperature has no notable direct effect on the autumn precipitation and water flow but potential indirect consequences are discussed. If precipitation were to increase during autumn as predicted, we will see an increase in both the peaks and amount of autumn high flows. However, these peaks will be lower than the current spring floods. We conclude that in large there is no reason for large changes in how the hydro industry conducts itself in relation to regulation of water flow in terms of infrastructure. There is however, possibly a need to increase the margin which one can store water in dams during longer periods with high flow together with more reliance on meteorological short term analysis to be better prepared for more sudden high flows.

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  • 128.
    Andersson, Elinor
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Starttillståndets inverkan på hydrologisk prognososäkerhet i HYPE-modellen2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Hydrological Forecast and Warning Service of The Swedish Meteorological and Hydrological Institute (SMHI) use meteorological ensemble forecasts as input in hydrological models. The hydrological ensemble forecasts take the uncertainty of future temperature and precipitation into account and serve as the basis of issued risks and warnings of high flows. Currently not considered is the uncertainty of the initial state, which consists of state variables in the model describing for instance soil water content and snow pack. This study assessed the impact of the initial state on forecasts in the hydrological model HYPE aiming to quantify the uncertainty and eventually enable more accurate forecasts.There were three aims of this study : 1) Evaluate a suggestion about how the initial state can be varied to give a good estimation of forecast uncertainty related to the hydrological initial state. 2) Examine the relationship between the spread of initial states and the hydrological forecast error. 3) Analyze the impact of seasons, catchment area, lake percentage, forest percentage and elevation on forecast uncertainty. A central hypothesis was that a smaller difference between the discharge of the initial state and the observed discharge results in more accurate forecasts. A restriction of the study was that the initial states only could be generated by disturbances of forcing data in before the forecast.Input data to the HYPE model were fifteen temperature and precipitation series, manipulated to generate an ensemble of different initial states. This ensemble was then used to make discharge forecasts with observed temperature and precipitation as forcing data. The study was performed on 76 catchments all over Sweden with data from the time period 1999-2008. Forecasts were made every day and the ensemble spread was evaluated 2, 4 and 10 days into the forecast. Autoregressive forecasts where the modelled discharge is corrected after the observed discharge were executed and evaluated as well. The results indicated a relationship between ensemble spread and forecast error, which implies that the spread can be used as a measure of the uncertainty of the initial state. The forecast error and ensemble spread correlated positively to forest percentage and negatively to catchment area, lake percentage and elevation. The same trend was detected between spread and catchment characteristics. The spread was biggest in winter and spring when normalization was made with mean discharge for the ten-year period and in spring and summer when normalization was done with mean discharge per month. The hypothesis that a smaller difference between the discharge of the initial state and the observed discharge results in more accurate forecasts was confirmed by the results. An implementation of an ensemble of different initial states in operational forecasts at SMHI’s Hydrological Forecast and Warning Service is suggested in order to further quantify the uncertainty of hydrological forecasts, and thereby improve the basis of judgment when issuing risks and warnings.

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  • 129.
    Andersson, Helén
    et al.
    SMHI, Research Department, Oceanography.
    Eriksson Bram, Lena
    SMHI, Core Services.
    Hjerdt, Niclas
    SMHI, Core Services.
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Löptien, Ulrike
    SMHI, Research Department, Oceanography.
    Strömqvist, Johan
    SMHI, Research Department, Hydrology.
    Översikt av beräkningsmodeller för bedömning av fiskodlingars näringsämnesbelastning på sjöar, vattendrag, magasin och kustvatten2016Report (Other academic)
    Abstract [sv]

    Den här rapporten är en kunskapssammanställning som utförts av SMHI på uppdrag av Havs- och Vattenmyndigheten. Den utgör inte något ställningstagande från Havs- och vattenmyndighetens sida. Rapporten försöker att sammanfatta den problematik som associeras med näringsämnesbelastningar från fiskodlingar i öppna kassar, vilka typer av beräkningar som kan behöva göras för att få en uppfattning om hur dessa kan påverka miljön samt några olika typer av modeller för detta ändamål.

    Fisk-, alg- och skaldjursodling är en växande industri runt om i världen som kan ge såväl näringsrik och hälsosam mat som arbetstillfällen. En nackdel med framförallt fiskodling i öppna kassar är att den kan innebära en påfrestning för vattenmiljön. De näringsämnen som ofta släpps ut från odlingen kan bidra till den övergödningsproblematik som redan finns i många sjöar och havsområden. Det är därför av största vikt att få en god uppskattning av den förväntade storleken på utsläppen förknippade med en öppen odling samt hur de kan tänkas förändra vattenkvaliteten på odlingsplatsen och dess närhet. Beräkningsmodeller kan vara till god hjälp vid bedömningen.

    Fiskar utsöndrar lösta näringsämnen och från odlingskassarna faller det också ut partikulärt organiskt material i form av fekalier och oätet foder. Storleken på näringsämneskällorna behöver beräknas och det finns modeller av olika komplexitet för att uppskatta detta. Storleken på det partikulära avfallet är viktigt dels för att det bidrarmed näringsämnen till vattnet och dels för att det kan ge upphov till ansamlingar av organiskt material på bottnen. När det organiska materialet bryts ner förbrukas syre och om ansamlingarna blir omfattande finns en risk för att det uppstår syrebrist vid bottnen. Om svavelväte bildas kan det orsaka skador på såväl den odlade fisken som det lokala ekosystemet. Odlingen kan också bidra till en försämrad vattenkvalitet i sin omgivning genom att tillgången av lösta näringsämnen blir större och därmed ge en ökad algproduktion. Den ökade algproduktionen skall i sin tur brytas ner och kan i förlängningen bidra till syrebristproblematiken.

    Det finns ett antal modeller som är specifikt utvecklade för fiskodlingar i öppna kassar och de tar i olika hög grad upp den beskrivna problematiken. Rapporten innehåller detaljerade genomgångar av några av modeller för att visa på styrkor och svagheter kring olika angreppsätt. Den innehåller också sammanfattningar av några vanligt förekommande modeller som använts internationellt vid bedömning av fiskodlingars miljöpåverkan. För att minska den negativa påverkan på vattenmiljön från har det också utvecklats recirkulerande system för odling. Rapporten tar inte upp belastning från den typen av fiskodlingar. Om utsläppen från ett sådant system är känt kan dock vattenkvalitetsmodeller användas för att se effekten av utsläpp från en punktkälla.

    Rapporten sammanfattar ett antal vattenkvalitetsmodeller för sjöar, vattendrag, kust och hav. En vattenkvalitetsmodell behöver inte nödvändigtvis vara utvecklad för att beskriva konsekvenser av fiskodlingar men bör kunna hantera frågeställningar som uppkommer vid bedömningar av övergödningsrisk vid utsläpp från en punktkälla. Den behöver därför kunna simulera parametrar såsom förändringen av näringsämneskoncentrationer, primärproduktion, siktdjup och syrgashalter på olika nivåer i vattenmassan. Modeller för den här typen av uppskattningar finns också i olika komplexitetsgrad och för olika skalor i tid och rum.

    Vid modellering är en god tillgång till observationer en förutsättning för pålitliga modellresultat och behövs såväl för att driva och kalibrera modellen som för validering av modellresultaten. Det är viktigt att tillgängliga data håller god kvalitet. En noggrann analys och beskrivning av den tillgängliga databasen hjälper därmed till att bedöma tillförlitligheten av modellsimuleringarna.

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  • 130.
    Andersson, Jafet
    et al.
    SMHI, Research Department, Hydrology.
    Ali, Abdou
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Gustafsson, David
    SMHI, Research Department, Hydrology.
    Minoungou, Bernard
    Providing peak river flow statistics and forecasting in the Niger River basin2017In: Physics and Chemistry of the Earth, ISSN 1474-7065, E-ISSN 1873-5193, Vol. 100, p. 3-12Article in journal (Refereed)
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  • 131.
    Andersson, Jafet
    et al.
    SMHI, Research Department, Hydrology.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Hjerdt, Niclas
    SMHI, Core Services.
    Combine and Share Essential Knowledge for Sustainable2016In: The Solutions Journal, ISSN 2154-0926, Vol. 7, no 3, p. 30-32Article in journal (Other (popular science, discussion, etc.))
  • 132.
    Andersson, Jafet
    et al.
    SMHI, Research Department, Hydrology.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Hjerdt, Niclas
    SMHI, Core Services.
    Combine and Share Essential Knowledge for Sustainable Water Management2016In: Solutions Journal, ISSN 2154-0896, E-ISSN 2154-0926, Vol. 7, no 3Article in journal (Other (popular science, discussion, etc.))
  • 133.
    Andersson, Jafet
    et al.
    SMHI, Research Department, Hydrology.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Traore, Farid
    Gustafsson, David
    SMHI, Research Department, Hydrology.
    Ali, Abdou
    Process refinements improve a hydrological model concept applied to the Niger River basin2017In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 31, no 25, p. 4540-4554Article in journal (Refereed)
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  • 134.
    Andersson, Jafet
    et al.
    SMHI, Research Department, Hydrology.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Van de Beek, Remco
    SMHI, Research Department, Hydrology.
    Hansryd, Jonas
    OpenMRG: Open data from Microwave links, Radar, and Gauges for rainfall quantification in Gothenburg, Sweden2022In: Earth System Science Data, ISSN 1866-3508, E-ISSN 1866-3516, Vol. 14, no 12, p. 5411-5426Article in journal (Refereed)
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    OpenMRG: Open data from Microwave links, Radar, and Gauges for rainfall quantification in Gothenburg, Sweden
  • 135.
    Andersson, Jafet
    et al.
    SMHI, Research Department, Hydrology.
    Pechlivanidis, Ilias
    SMHI, Research Department, Hydrology.
    Gustafsson, David
    SMHI, Research Department, Hydrology.
    Donnelly, Chantal
    SMHI, Research Department, Hydrology.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Key factors for improving large-scale hydrological model performance2015In: European Water, ISSN 1792-085X, Vol. 49, p. 77-88Article in journal (Refereed)
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    fulltext
  • 136.
    Andersson, Jafet
    et al.
    SMHI, Research Department, Hydrology.
    Van de Beek, Remco
    SMHI, Research Department.
    SIMULERING AV AVLOPPSFLÖDEN MED REGNDATAFRÅN MOBILTELEFONNÄT I STOCKHOLM: SIMULATING URBAN DRAINAGE FLOWS WITH RAINFALLDATA DERIVED FROM MOBILE PHONE NETWORKS INSTOCKHOLM2021In: Vatten, ISSN 0042-2886, no 2, p. 91-104Article in journal (Other academic)
    Abstract [en]

    Municipal water utilities often only have access to a sparse network of rain gauges (ca. 10 in Stockholm).With sparse networks there is a risk to under- or overestimate sewer flow calculations when showers passbetween gauges, or when a spatially concentrated shower hits a gauge. Moreover, significant resourcesare required to keep the gauge network operational and reliable. Microwave links in telecommunicationnetworks can measure rainfall. The link network is much denser than the gauge network (here we study500 links in Stockholm), and is continuously maintained. Such links can hence be a valuable complementto gauges. This study initially compares link-based and gauge-based rainfall data. Generally, we observedlower maximum intensities for the links compared with the gauges: the shorter the duration the largerthe difference. Subsequently, we investigate how increasing network density and different types of raindata affects runoff, pipe flow and overflow in the sewer network using a hydraulic model. The resultsshow large differences in calculated flow between varying network densities (sometimes +/-80 %), andthat doubling the density often was sufficient during the seven studied rain events. Increasing the densityusing microwave links also gave better correspondence with measured inflow to the Henriksdal sewagetreatment plant. In summary, operational telecommunication networks have a large potential to complement rain gauges for water utilities.

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    SIMULERING AV AVLOPPSFLÖDEN MED REGNDATA FRÅN MOBILTELEFONNÄT I STOCKHOLM
  • 137.
    Andersson, Jafet
    et al.
    SMHI, Research Department, Hydrology.
    Zehnder, Alexander J. B.
    Wehrli, Bernhard
    Jewitt, Graham P. W.
    Abbaspour, Karim C.
    Yang, Hong
    Improving Crop Yield and Water Productivity by Ecological Sanitation and Water Harvesting in South Africa2013In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 47, no 9, p. 4341-4348Article in journal (Refereed)
    Abstract [en]

    This study quantifies the potential effects of a set of technologies to address wafer and fertility constraints in rain. fed smallholder agriculture in South Africa, namely in situ water harvesting (WH), external WH, and ecological sanitation (Ecosan, fertilization with human urine); We Used the Soil and Water Assessment Tool to model spatiotemporally differentiated effects on maize yield, river flow, evaporation, and transpiration. Ecosan Met some of the plant nitrogen demands, which significantly increased maize yields by 12% and transpiration by 2% on average across South Africa. In situ and external WH did not significantly affect the yield, transpiration or river flow on the South Africa scale. However, external WH. more than doubled the yields for specific seasons and locations. WH particularly increased the lowest yields. Significant, water and nutrient demands remained even with WH and Ecosan management. Additional fertility enhancements raised the yield levels but also the yield variability, whereas soil moisture enhancements improved the yield stability. Hence, coupled policies' addressing both constraints will likely be Most effective for improving food security.

  • 138.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Becker, Björn
    SMHI.
    Hillgren, Robert
    SMHI.
    Brofjordens kraftstation: Kylvattenspridning i Hanneviken1990Report (Other academic)
    Abstract [sv]

    Vattenfall planerar att lokalisera en restoljeförgasningsanläggning intill Scanraff vid Brofjorden. Anläggningens kylvattenutsläpp beräknas till 7,5 m3/s med eninitiell övertemperatur på cirka 10 °C. Alternativa utsläppspunkter är söder om Hanneviksholmen och södra Trommekilen.

    En frågeställning är huruvida man genom lämpligt val av utsläppsarrangemang kan få en gynnsam uppvärmning av Hanneviken och därigenom förbättra förutsättningarna för en produktion av växtplankton.Tillgången på växtplankton är en förutsättning för en tänkt ostronodling norr om Hanneviksholmen.

    SMHI har fått i uppdrag av Vattenfall Utveckling AB att utreda kylvattenspridningen för två alternativa utsläpp i Hanneviken. Arbetet har omfattat simuleringar av cirkulationsförhållandena och kylvattenspridningen samt fältundersökningar. Fältmätningarna har syftat till dels att verifiera modellens resultat dels att få en uppfattning om hur stor del av året man kan förvänta en gynnsam uppvärmning av Hanneviken.

    Uppvärmningen av Hanneviken är starkt beroende av vindens riktning.För ostlig vind är temperaturhöjningen mindre än 2 °C,medan den är 3-5 °C för sydostlig eller sydvästlig vind.

    Uppvärmningen av vattnet längs kusten nordost om Kågarna blir 2-3 °C.

    Utsläppsalternativ 1 ger en något högre uppvärmning.

    Vindar från SE över S till W är mest gynnsamma för en inström väster om Hanneviksholmen och därmed en spridning av kylvatten in mot Hanneviken. Andelen av dessa vindar under året uppskattas till cirka 50%.

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  • 139.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Hillgren, Robert
    SMHI, Core Services.
    SMHIs undersökningar i Öregrundsgrepen 19861987Report (Other academic)
    Abstract [sv]

    1986 kan kraftverkets drift betraktas som normal med avseende på kylvattenflöde och värme. Samtliga tre block har haft ett högt driftutnyttjande.

    Kontrollprogrammets målsättning har varit att kontinuerligt övervaka kylvattnets spridning i tid och rum. Av särskilt intresse har varit att övervaka effekterna av läckaget från F 3:s kylvattenkanal. Tätningsarbetena påbörjades under F 3:s revisionsperiod under sensommaren och var avslutade i slutet av november. Följande slutsatser har dragits:

    • Tre-blocksdriften under december har inneburit avkylningsytor av storleken 6 - 8 km?Under två-blocksdrift är motsvarande ytor 4 - 7 km2
    • Området mellan St Sandgrund och vallen påverkas mest av läckaget.
    • 10°C övertemperatur har förekommit närmast vallen.
    • Vid driftstopp1 F 3:s revisionsperiod, avkyls det berörda läckageområdet.Ingen förekomst av uppvärmt kylvatten kan konstateras under revisionsperioden.
    • Vid idrifttagande av F 3 har omgående vattenområdet påverkats.
    • Drift under islagd period har medfört att öppet vatten förekommit utanför vallen hela tiden trots den svåra isvintern.
    • Ett extremt vattenstånd+ 143 cm över MW har förekommit (jfr med+ 150 cm vilket motsvarar "hundraårsvattenståndet").
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  • 140.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Hillgren, Robert
    SMHI, Core Services.
    SMHIs undersökningar utanför Forsmark 19871988Report (Other academic)
    Abstract [sv]

    1987 kan kraftverkets drift betraktas som normal med avseende på kylvattenflöde och värme. Samtliga tre block har haft ett högt drift utnyttjande.

    Kontrollprogrammets målsättning har varit att kontinuerligt övervaka kylvattnets spridning i tid och rum. Av särskilt intresse har varit att se effekten av kylvattentillskottet från block 3 via ordinarie utlopp.

    Följande slutsatser har dragits:

    • Treblocksdriften under året har inneburit avkylningsytor av storleksordningen 7 - 12 km2. Den tidigare bedömningen med endast karteringar från december 1986, var 6 - 8 km2.
    • Temperaturen i skärgårdsområdet har inte påverkats av treblocksdriften.
    • Något fortsatt läckage från F 3:s kylvattenkanal har inte observerats.
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  • 141.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Hillgren, Robert
    SMHI, Core Services.
    SMHIs undersökningar utanför Forsmark 19881989Report (Other academic)
    Abstract [sv]

    1988 kan kraftverkets drift betraktas som normal med avseende på kylvattenflöde och värme. Samtliga tre block har haft ett högt driftutnyttjande.

    Reservutskovet har dock nyttjats mer än föregående år, ca 3 månader.

    Kontrollprogrammets målsättning har varit att kontinuerligt övervaka kylvattnets spridning i tid och rum. Av särskilt intresse har varit att se effekten av  kylvattentillskottet från block 3 via ordinarie utlopp.

    Följande slutsatser har dragits:

    • Treblocksdriften under året har inneburit avkylningsytor av storleksordningen 8 - 16 km 2. Den tidigare bedömningen från 1987; var 7 - 12 km2.
    • Temperaturen i skärgårdsområdet har inte påverkats av treblocksdriften.
    • Något märkbart läckage från F 3:s kylvattenkanal har inte observerats.
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  • 142.
    Andersson, Jan
    et al.
    SMHI.
    Hillgren, Robert
    SMHI, Core Services.
    SMHIs undersökningar utanför Forsmark 19891990Report (Other academic)
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  • 143.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Hillgren, Robert
    SMHI, Core Services.
    SMHIs undersökningar utanför Forsmark 19921993Report (Other academic)
    Abstract [sv]

    1992 års kontrollprogram har haft som målsättning att:

    - kontinuerligt bevaka temperaturen i vertikal Si skärgårdsområdet.

    - kontrollera vattenområdet vid F3:s kylvattenkanal (tidigare läckaget).

    Kraftverkets drift under 1992 kan betraktas som normal med avseende på kylvattenflöde och värme.

    Reservutskovet har använts i drygt 1 månad. Under 1990 och 1991 var motsvarande tid cirka 6 månader. Att perioden varit så mycket längre under de två föregående åren har berott på att Kustlaboratoriet i Öregrund bedrivit ett försök att skapa möjligheter för en förbättrad fiskreproduktion.

    Kommentarer:

    * Tendensen av något förhöjda temperaturer under åren 1990 - 91 i skärgårdsområdet vid vertikal S har brutits. Temperaturen ligger på en mer normal nivå genom att reservutskovet utnyttjats betydligt mindre under 1992.

    * Det fanns inga spår av det tidigare läckaget utanför F3:s kylvattenkanal.

    Statistiskt sett var årsmedeltemperaturen (april - november) under -92 i vertikal Spå 1 m djup 0.23°C över medelvärdet för perioden 1977-91. För 1991 och 1990 låg årsmedeltemp. 2.2°C resp l.8°C över medelvärdet.

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  • 144.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Hillgren, Robert
    SMHI, Core Services.
    SMHIs undersökningar utanför Forsmark 19931994Report (Other academic)
    Abstract [sv]

    1993 års kontrollprogram har haft som målsättning att:

    - kontinuerligt bevaka temperaturen i vertikal S i skärgårdsområdet

    - kontrollera vattenområdet vid F3:s kylvattenkanal (tidigare läckaget).

    Kraftverkets drift under 1993 kan betraktas som normal med avseende på kylvattenflöde och värme.

    Reservutskovet har använts i drygt 1 månad. Under 1990 och 1991 var motsvarande tid cirka 6 månader. Att perioden varit så mycket längre under de två åren har berott på att Kustlaboratoriet i Öregrund bedrivit ett försök att skapa möjligheter för en förbättrad fiskreproduktion.

    Kommentarer:

    * Temperaturen ligger på en fortsatt normal nivå genom att reservutskovet   utnyttjats betydligt mindre under 1992.

    * Det fanns inga spår av det tidigare läckaget utanför F3:s kylvattenkanal.

    Statististiskt sett var årsmedeltemperaturen (april - november) under -93 i vertikal Spå 1 m djup 0.l8°C under medelvärdet för perioden 1977-92.

    För 1991 och 1990 låg årsmedeltemp. 2.2°C resp l.8°C över medelvärdet, samt för 1992 låg årsmedeltemp. 0.23°C över medelvärdet.

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  • 145.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Hillgren, Robert
    SMHI, Core Services.
    SMHIs undersökningar utanför Forsmark 19941995Report (Other academic)
    Abstract [sv]

    Kraftverkets drift under 1994 kan betraktas som normal med avseende på kylvattenflöde och värme.

    Kylvatten från Fl och F2 har släppts via reservutskovet under 5 månader. Detta på grund av problem med rensningen av fiskspärren vid biotestsjöns utlopp. Den sammantagna effekten av kylvatten från reservutskovet och en värmebölja medförde att den hittills högsta uppmätta temperaturen i vertikal S, 25.2°C noterades den 2 augusti. Årsmedeltemperaturen (april - november) under 1994 i vertikal S på 1 m djup låg 1.7 °C över medelvärdet för perioden 1977 - 1993 (april - november).

    1994 års temperaturöverskott uppstod framförallt under sommaren, under senhösten ökade vattenutbytet med det utanförliggande havsområdet och någon ackumulering av kylvatten kunde inte registreras.

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  • 146.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Hillgren, Robert
    SMHI, Core Services.
    SMHIs undersökningar utanför Forsmark 19951996Report (Other academic)
    Abstract [sv]

    Målsättning för 1995 års kontrollprogram har varit att kontinuerligt bevaka temperaturen i vertikal S i skärgårdsområdet.

    Kylvatten har släppts via reservutskovet vid olika tillfällen under sammanlagt 5 månader. Största delen av utsläppen har skett under andra halvåret. Detta pga problem med rensningen av fiskspärren vid Biotestsjöns utlopp. För 1994 rådde liknande förhållanden.

    Effekten av kylvatten från reservutskovet och en vann inledning på hösten ("brittsommar") medförde att den hittills högsta månadsmedeltemperaturen för oktober noterades (vertikal S på 1 m djup 11.82°C). Årsmedeltemperaturen (april-nov) under 1995 låg 1 °C över medelvärdet för perioden 1977-94 (april-nov ). Motsvarande siffra för 1994 var 1. 7°C.

    1995 års temperaturöverskott uppstod framförallt under augusti-september- oktober. I  november ökade vattenutbytet med det utanförliggande havsområdet och någon ackumulering av kylvatten kunde inte registreras.

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  • 147.
    Andersson, Jan
    et al.
    SMHI, Core Services.
    Hillgren, Robert
    SMHI, Core Services.
    Westring, Gustaf
    SMHI.
    Strömmar, skiktningsförhållanden, vattenståndsvariationer mellan Cebu och Leyte, Filippinerna.: -En förstudie inför sjökabelläggning i områdetTyp: Rapport1992Report (Other academic)
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  • 148.
    Andersson, Kerstin
    SMHI, Core Services.
    Svenskt sjöregister. 2 delar: Svenskt Vattenarkiv1996Report (Other academic)
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  • 149.
    Andersson, Kerstin
    SMHI, Core Services.
    Vattenföring i Sverige. Del 1. Vattendrag till Bottenviken: Svenskt Vattenarkiv1995Report (Other academic)
    Abstract [sv]

    En viktig uppgift för SMHI är att ge information om vattenföringen i Sveriges vattendrag. "Vattenföringen i Sveriges floder" utkom 1954. Den sammanställdes av Ragnar Melin och innehöll uppgifter tom är 1950. En ny utgåva, "Vattenföring i Sverige", publicerades 1979. Den innehåller minst 10 år långa mätserier för de vattenföringsstationer som var i drift 1975 samt för vissa tidigare nedlagda stationer.

    Denna utgåva innehåller vattenföringsuppgifter t o m 1990 för de vattenföringsstationer som var i drift 1990 och som har en mätserie på minst 10 år.

    SMHI publicerar denna gäng "Vattenföring i Sverige" i fyra delar. Indelningen av Sverige är densamma som i "Arealer för avrinningsområden", som samtidigt är under utgivning. De olika delarna omfattarDel 1 vattendrag som mynnar i BottenvikenDel 2 vattendrag som mynnar i BottenhavetDel 3 vattendrag som mynnar i Egentliga ÖstersjönDel 4 vattendrag som mynnar i Västerhavet ( Öresund, Kattegatt, Skagerrak).

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  • 150.
    Andersson, Kerstin
    SMHI, Core Services.
    Vattenföring i Sverige. Del 2. Vattendrag till Bottenhavet: Svenskt Vattenarkiv1995Report (Other academic)
    Abstract [sv]

    En viktig uppgift för SMHI är att ge information om vattenföringen i Sveriges vattendrag. "Vattenföringen i Sveriges floder" utkom 1954. Den sammanställdes av Ragnar Melin och innehöll uppgifter tom år 1950. En nyutgåva, "Vattenföring i Sverige", publicerades 1979. Den innehåller minst 10 år långa mätserier för de vattenföringsstationer som var i drift 1975 samt för vissa tidigare nedlagda stationer. Denna utgåva innehåller vattenföringsuppgifter t o m 1990 för de vattenföringsstationer som var i drift 1990 och som har en mätserie på minst 10 år.

    SMHI publicerar denna gång "Vattenföring i Sverige" i fyra delar. Indelningen av Sverige är densamma som i "Arealer för avrinningsområden", som samtidigt är under utgivning. De olika delarna omfattar

    Del 1 vattendrag som mynnar i BottenvikenDel 2 vattendrag som mynnar i BottenhavetDel 3 vattendrag som mynnar i Egentliga ÖstersjönDel 4 vattendrag som mynnar i Västerhavet ( Öresund, Kattegatt, Skagerrak).

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