Change search
Refine search result
1234567 1 - 50 of 625
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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)
  • Disputation date (earliest first)
  • Disputation date (latest 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)
  • Disputation date (earliest first)
  • Disputation date (latest 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.
  • 1. Aggarwal, Pradeep K.
    et al.
    Romatschke, Ulrike
    Araguas-Araguas, Luis
    Belachew, Dagnachew
    Longstaffe, Frederick J.
    Berg, Peter
    SMHI, Research Department, Hydrology.
    Schumacher, Courtney
    Funk, Aaron
    Proportions of convective and stratiform precipitation revealed in water isotope ratios2016In: Nature Geoscience, ISSN 1752-0894, E-ISSN 1752-0908, Vol. 9, no 8, p. 624-+Article in journal (Refereed)
  • 2.
    Ahlkrona, Malva
    SMHI.
    Phospherous in a Biogeochemical Lake Model2002Report (Other academic)
    Abstract [en]

    BIOLA isa biogeochemical lake model within the V ASTRA research programme. The model's

    main purpose is to predict the ecological responses to changed nutrient loads. The phosphorus simulations were not satisfactory and the sediment was thought to be the critical part. The aim of this work was to improve the phosphorus simulations. Therefore a new sediment approach has been developed. Three main changes of the sediment processes were carried through:

    • Resuspension of sediments from erosion and transportation bottoms was added

    • The sediments were divided into an upper, aerobic, and a lower, anaerobic, layer

    • The relation between sorbed and dissolved phosphorus in the sediments was described by

    Langmuir isotherms, with a sorption 2.5 times higher at aerobic compared to anaerobic

    conditions

    The modelling of total phosphorus and blue-green algae was improved. Especially the timing of high concentration peaks was much better. One problem still lingering is the modelled oxygen levels, which were much higher than the observed levels. Therefore the model has not been tested for anaerobic conditions. A verage release rates from the sediments were 2.5 mg Pa-1 <luring the summer, which is reasonable. A 20-year simulation of step-response was run with increased and decreased nutrient loads. Roughly four years after the change, the model had reached a new equilibrium.

  • 3. Aich, Valentin
    et al.
    Liersch, Stefan
    Vetter, Tobias
    Andersson, Jafet
    SMHI, Research Department, Hydrology.
    Mueller, Eva N.
    Hattermann, Fred F.
    Climate or Land Use?-Attribution of Changes in River Flooding in the Sahel Zone2015In: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 7, no 6, p. 2796-2820Article in journal (Refereed)
    Abstract [en]

    This study intends to contribute to the ongoing discussion on whether land use and land cover changes (LULC) or climate trends have the major influence on the observed increase of flood magnitudes in the Sahel. A simulation-based approach is used for attributing the observed trends to the postulated drivers. For this purpose, the ecohydrological model SWIM (Soil and Water Integrated Model) with a new, dynamic LULC module was set up for the Sahelian part of the Niger River until Niamey, including the main tributaries Sirba and Goroul. The model was driven with observed, reanalyzed climate and LULC data for the years 1950-2009. In order to quantify the shares of influence, one simulation was carried out with constant land cover as of 1950, and one including LULC. As quantitative measure, the gradients of the simulated trends were compared to the observed trend. The modeling studies showed that for the Sirba River only the simulation which included LULC was able to reproduce the observed trend. The simulation without LULC showed a positive trend for flood magnitudes, but underestimated the trend significantly. For the Goroul River and the local flood of the Niger River at Niamey, the simulations were only partly able to reproduce the observed trend. In conclusion, the new LULC module enabled some first quantitative insights into the relative influence of LULC and climatic changes. For the Sirba catchment, the results imply that LULC and climatic changes contribute in roughly equal shares to the observed increase in flooding. For the other parts of the subcatchment, the results are less clear but show, that climatic changes and LULC are drivers for the flood increase; however their shares cannot be quantified. Based on these modeling results, we argue for a two-pillar adaptation strategy to reduce current and future flood risk: Flood mitigation for reducing LULC-induced flood increase, and flood adaptation for a general reduction of flood vulnerability.

  • 4. Aich, Valentin
    et al.
    Liersch, Stefan
    Vetter, Tobias
    Fournet, Samuel
    Andersson, Jafet
    SMHI, Research Department, Hydrology.
    Calmanti, Sandro
    van Weert, Frank H. A.
    Hattermann, Fred F.
    Paton, Eva N.
    Flood projections within the Niger River Basin under future land use and climate change2016In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 562, p. 666-677Article in journal (Refereed)
    Abstract [en]

    This study assesses future flood risk in the Niger River Basin (NRB), for the first time considering the simultaneous effects of both projected climate change and land use changes. For this purpose, an ecohydrological process-based model (SWIM) was set up and validated for past climate and land use dynamics of the entire NRB. Model runs for future flood risks were conducted with an ensemble of 18 climate models, 13 of them dynamically downscaled from the CORDEX Africa project and five statistically downscaled Earth System Models. Two climate and two land use change scenarios were used to cover a broad range of potential developments in the region. Two flood indicators (annual 90th percentile and the 20-year return flood) were used to assess the future flood risk for the Upper, Middle and Lower Niger as well as the Benue. The modeling results generally show increases of flood magnitudes when comparing a scenario period in the near future (2021-2050) with a base period (1976-2005). Land use effects are more uncertain, but trends and relative changes for the different catchments of the NRB seem robust. The dry areas of the Sahelian and Sudanian regions of the basin show a particularly high sensitivity to climatic and land use changes, with an alarming increase of flood magnitudes in parts. A scenario with continuing transformation of natural vegetation into agricultural land and urbanization intensifies the flood risk in all parts of the NRB, while a "regreening" scenario can reduce flood magnitudes to some extent. Yet, land use change effects were smaller when compared to the effects of climate change. In the face of an already existing adaptation deficit to catastrophic flooding in the region, the authors argue for a mix of adaptation and mitigation efforts in order to reduce the flood risk in the NRB. (C) 2016 Elsevier B.V. All rights reserved.

  • 5. Akselsson, Cecilia
    et al.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Belyazid, Salim
    Capell, Réne
    SMHI, Research Department, Hydrology.
    Can increased weathering rates due to future warming compensate for base cation losses following whole-tree harvesting in spruce forests?2016In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 128, no 1-2, p. 89-105Article in journal (Refereed)
  • 6.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Edman, Moa
    SMHI, Research Department, Oceanography.
    Eilola, Kari
    SMHI, Research Department, Oceanography.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Sahlberg, Jörgen
    SMHI, Professional Services.
    Modelling nutrient retention in the coastal zone of an eutrophic sea2016In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 13, no 20, p. 5753-5769Article in journal (Refereed)
  • 7.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Eilola, Kari
    SMHI, Research Department, Oceanography.
    Hordoir, Robinson
    SMHI, Research Department, Oceanography.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Hall, Per O. J.
    Transport of fresh and resuspended particulate organic material in the Baltic Sea - a model study2011In: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 87, no 1, p. 1-12Article in journal (Refereed)
    Abstract [en]

    A fully coupled high-resolution 3-dimensional biogeochemical-physical ocean model including an empirical wave model was used to investigate the long-term average (1970-2007) distributions and transports of resuspended matter and other types of suspended organic matter in the Baltic Sea. Modelled bottom types were compared to observations and the results showed that the model successfully managed to capture the horizontal, as well as the vertical, distribution of the different bottom types: accumulation, transport and erosion bottoms. The model also captured well the nutrient element contents in the sediments. On average the largest contribution of resuspended organic carbon to the transport of total organic carbon is found at erosion and transport bottoms. Although the relative transport of resuspended organic carbon at deeper accumulation bottoms in general is low (< 10% of total), the central parts of the sub-basins act on average as sinks that import organic matter while the more shallow areas and the coastal regions acts as sources of organic carbon in the water column. This indicates that the particulate organic matter produced in erosion and transport areas might be kept in suspension long enough to be transported and settle in less energetic areas, i.e. on accumulation bottoms. (C) 2011 Elsevier B.V. All rights reserved.

  • 8.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Eilola, Kari
    SMHI, Research Department, Oceanography.
    Kuznetsov, Ivan
    Hall, Per O. J.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    A new approach to model oxygen dependent benthic phosphate fluxes in the Baltic Sea2015In: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 144, p. 127-141Article in journal (Refereed)
    Abstract [en]

    The new approach to model the oxygen dependent phosphate release by implementing formulations of the oxygen penetration depths (OPD) and mineral bound inorganic phosphorus pools to the Swedish Coastal and Ocean Biogeochemical model (SCOBI) is described. The phosphorus dynamics and the oxygen concentrations in the Baltic proper sediment are studied during the period 1980-2008 using SCOBI coupled to the 3D-Rossby Centre Ocean model. Model data are compared to observations from monitoring stations and experiments. The impact from oxygen consumption on the determination of the OPD is found to be largest in the coastal zones where also the largest OPD are found. In the deep water the low oxygen concentrations mainly determine the OPD. Highest modelled release rate of phosphate from the sediment is about 59 x 10(3) t P year(-1) and is found on anoxic sediment at depths between 60-150 m, corresponding to 17% of the Baltic proper total area. The deposition of organic and inorganic phosphorus on sediments with oxic bottom water is larger than the release of phosphorus, about 43 x 10(3) t P year(-1). For anoxic bottoms the release of total phosphorus during the investigated period is larger than the deposition, about 19 x 10(3) t P year(-1). In total the net Baltic proper sediment sink is about 23.7 x 10(3) t P year(-1). The estimated phosphorus sink efficiency of the entire Baltic Sea is on average about 83% during the period. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

  • 9.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Skogen, Morten D.
    A North Sea and Baltic Sea Model Ensemble Eutrophication Assessment2010In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 39, no 1, p. 59-69Article in journal (Refereed)
    Abstract [en]

    A method to combine observations and an ensemble of ecological models is suggested to produce a eutrophication assessment. Using threshold values and methodology from the Oslo and Paris Commissions (OSPAR) and the Helsinki Commission (HELCOM), four models are combined to assess eutrophication for the Baltic and North Seas for the year 2006. The assessment indicates that the entire southeastern part of the North Sea, the Kattegat, the Danish Straits, the Gulf of Finland, and the Gulf of Riga as well as parts of the Arkona Basin, the Bornholm Basin, and the Baltic proper may be classified as problem areas. The Bothnian Bay and parts of the Baltic proper, the Bornholm Basin, and the Arkona Basin are classified as potential problem areas. This method is a useful tool for the classification of eutrophication; however, the results depend on the threshold values, and further work is needed within both OSPAR and HELCOM to harmonize these values.

  • 10.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Skogen, Morten
    Sehested Hansen, Ian
    DHI Water and Environments.
    Stipa, Tapani
    University of Helsinki.
    Niiranen, Susa
    Stockholm University.
    The Year 2006 An Environmental Status report of the North Sea, Skagerrak, Kattegat and the Baltic Sea2007In: BANSAI- The Baltic and North Sea marine environmental modelling Asessment Initaiative / [ed] the Nordic Council of Ministers’ Sea and Air Group, 2007Conference paper (Other academic)
  • 11. Amaguchi, H.
    et al.
    Kawamura, A.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Takasaki, T.
    Development and testing of a distributed urban storm runoff event model with a vector-based catchment delineation2012In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 420, p. 205-215Article in journal (Refereed)
    Abstract [en]

    The recent advances in GIS technology as well as data availability open up new possibilities concerning urban storm runoff modeling. In this paper, a vector-based distributed storm event runoff model - the Tokyo Storm Runoff (TSR) model - is developed and tested for urban runoff analysis using two historical storm events. The set-up of this model is based on urban landscape GIS delineation that faithfully describes the complicated urban land use features in detail. The flow between single spatial elements is based on established hydraulic and hydrological models with equations that describe all aspects of storm runoff generation in an urban environment. The model was set up and evaluated for the small urban lower Ekota catchment in Tokyo Metropolis, Japan. No calibration or tuning was performed, but the general model formulation was used with standard parameter values obtained from the literature. The runoff response to two storm events were simulated; one minor event resulting only in a small-scale flood wave and one major event which inundated parts of the catchment. For both events, the simulated water levels closely reproduced the observed ones. For the major event, also the reported inundation area was well described by the model. It was also demonstrated how the model can be used to evaluate the flow conditions in specific components of the urban hydrological system, which facilitates e.g. evaluation of flood-preventive measures. (C) 2011 Elsevier B.V. All rights reserved.

  • 12. Aminot, A
    et al.
    Kirkwood, D
    Carlberg, Stig
    SMHI, Research Department, Oceanography.
    The QUASIMEME laboratory performance studies (1993-1995): Overview of the nutrients section1997In: Marine Pollution Bulletin, ISSN 0025-326X, E-ISSN 1879-3363, Vol. 35, no 1-6, p. 28-41Article in journal (Refereed)
    Abstract [en]

    The QUASIMEME Project (1993-1996) was established to assist European laboratories to improve the data they produce in marine monitoring programmes. Through laboratory performance Studies (with six-monthly reports), workshops and expert visits the programme was fully interactive. There were five rounds of laboratory performance studies. For the nutrient section, in which about 50 laboratories took part, the reference materials distributed to the participants consisted of standard solutions of nutrients and seawater samples stabilized by autoclaving. The material included low and high concentrations typical of those encountered in coastal seawater; at least two samples with different concentrations were distributed in each round. Robust statistics were used to determine the means and standard deviations for each set of results. For inorganic nutrients, the assessment of the data for bias and precision was based mainly on a Z- and P-scoring system in which targets of +/- 6% were allocated to the high concentrations, likewise +/- 12.5% to the low concentrations. This overview discusses overall performance separately for nitrate plus nitrite, nitrite, ammonia, phosphate, total nitrogen and total phosphorus, and classifies the performance of individual laboratories in each round, while maintaining their anonymity. Performance for nitrate plus nitrite and nitrite improved steadily and these determinands are now fully under control; at the end of the programme, standard deviations (SD) for nitrate plus nitrite were 0.2 mu mol l(-1) at low concentration and 0.6 mu mol l(-1) (4%) at high concentration, and for nitrite they were 0.03 mu mol l(-1) and 0.06 mu mol l(-1) (5%) respectively. Phosphate showed a somewhat stable level of performance with SD of 0.06 mu mol l(-1) and 0.10 mu mol l(-1) (10%) at low and high concentrations respectively, but this could be improved. Ammonia proved the most difficult to determine, and in spite of a substantial improvement at the beginning of the exercise, this determinand is not under control in many laboratories. At low concentrations, ammonia shows a positive bias of 0.2 mu mol l(-1) and a SD of 0.3 mu mol l(-1), while at high concentrations SD reaches 0.5 mu mol l(-1) (20%). For total nitrogen (TN) and total phosphorus (TP), the exercises show that only two thirds of the participants produced consistent data for TN, and less than half of them produced consistent data for TP. (C) 1997 Elsevier Science Ltd. All rights reserved.

  • 13. 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.

  • 14. 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.

  • 15. 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.

  • 16. 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)
  • 17. 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
    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.

  • 18.
    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.

  • 19.
    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)
  • 20.
    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.))
  • 21.
    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.))
  • 22.
    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)
  • 23.
    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)
  • 24.
    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.

  • 25.
    Andersson, Kerstin
    SMHI, Core Services.
    Svenskt sjöregister. 2 delar: Svenskt Vattenarkiv1996Report (Other academic)
  • 26.
    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).

  • 27.
    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).

  • 28.
    Andersson, Kerstin
    SMHI, Core Services.
    Vattenföring i Sverige. Del 3. Vattendrag till Egentliga Östersjön: Svenskt Vattenarkiv1993Report (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 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).

  • 29.
    Andersson, Kerstin
    SMHI, Core Services.
    Vattenföring i Sverige. Del 4. Vattendrag till Västerhavet: Svenskt Vattenarkiv1994Report (Other academic)
    Abstract [sv]

    En viktig uppgift för SMH1 är att ge information om vattenföringen i Sveriges vattendrag. "Vattenföringen i Sveriges floder" utkom l954. Den sammanställdes av Ragnar Melin och innehöll uppgifter tom år 1950. En ny utgåva, "Vattenföring i Sverige", publicerades 1979. Den innehåller minst 10 är långa mätserier för de vattenföringsstationer som var i drift 1975 samt för vissa tidigare nedlagda stationer.Denna utgåva innehåller vattenföringsuppgifter tom 1990 för de vattenföringsstationer som var i drift 1990 och som har en rnätserie 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.e 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).

  • 30.
    Andersson, Lars
    SMHI, Core Services.
    Trends in nutrient and oxygen concentrations in the Skagerrak-Kattegat1996In: Journal of Sea Research, ISSN 1385-1101, E-ISSN 1873-1414, Vol. 35, no 1-3, p. 63-71Article in journal (Refereed)
    Abstract [en]

    The Skagerrak and Kattegat form a transition zone between the Baltic and the North Sea. Both areas are subject to increased nutrient loads. In this paper a non-parametric method is used to calculate the changes in nutrient and oxygen concentrations in the area. The period chosen was 1971 to 1990 and the parameters were dissolved inorganic nitrogen, phosphorus, silicate, total nitrogen and total phosphorus together with oxygen and oxygen saturation. Data have been sorted after salinity and the analyses have been carried out for different water masses and subareas. The results demonstrate that both surface and deep water in the Kattegat show increasing trends during winter for all nutrients except silicate. During summer there is an increase in total nitrogen and total phosphorus while silicate shows a decrease. In the Skagerrak the picture is more variable; in the eastern part, however, there is a clear increase for all inorganic nutrients during winter in the coastal water. Oxygen shows a declining trend in most areas.

  • 31.
    Andersson, Lars
    et al.
    SMHI, Core Services.
    Rahm, Lars
    SMHI, Research Department, Oceanography.
    THERMALLY DRIVEN CIRCULATION WITHIN AN EXPERIMENTAL ENCLOSURE1990In: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 30, no 2, p. 111-129Article in journal (Refereed)
  • 32.
    Andersson, Lars
    et al.
    SMHI, Core Services.
    RYDBERG, L
    EXCHANGE OF WATER AND NUTRIENTS BETWEEN THE SKAGERRAK AND THE KATTEGAT1993In: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 36, no 2, p. 159-181Article in journal (Refereed)
  • 33.
    Andersson, Lotta
    SMHI, Core Services.
    Experiences of the use of riverine nutrient models in stakeholder dialogues2004In: International Journal of Water Resources Development, ISSN 0790-0627, E-ISSN 1360-0648, Vol. 20, no 3, p. 399-413Article in journal (Refereed)
    Abstract [en]

    The potential of models to assist in stakeholder dialogues is assessed regarding options for the reduction of riverine nitrogen loads in a 357-km(2) river basin in south central Sweden. Scenarios of remedies based on stakeholders' suggestions were used to stimulate discussions in a panel incorporating farmers, municipality staff, politicians and technical advisers. The farmers perceived the model-derived discussion material as valuable, although only average conditions at a generic farm were simulated. The panellists demonstrated caution when using regionalized information, but did not request quantitative uncertainty estimates. There was a desire to have phosphorus included in the model-derived discussion material and to include the impacts of other environmental goals than 'no eutrophication'. The inclusion of different stakeholder groups in the panel sessions was acknowledged as a way to establish a shared perception of the existing environmental status of the basin and to define the pros and cons of various remedies. This was seen by the panellists as a way to facilitate local implementation of the Water Framework Directive (WFD). Use of model-stimulated local stakeholder panels is also a way to ensure that involved stakeholders perceive local environmental goals as realistic and acceptable. However, to establish river-basin stakeholder dialogues as part of the nation-wide implementation of the WFD directive, it will be necessary to develop a model approach that can be used by local advisers. Perhaps the most critical factor is the moderators' ability to provide an atmosphere of mutual respect between all those involved in contrast to performing one-way lectures to the participants.

  • 34.
    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, p. 93-105Article 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).

  • 35.
    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, p. 63-77Article 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.

  • 36.
    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, p. 267-274Article in journal (Other academic)
  • 37.
    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, p. 439-447Article 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.

  • 38.
    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, p. 521-532Article 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.

  • 39.
    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, p. 217-228Article 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.

  • 40.
    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, p. 43-57Article 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.

  • 41.
    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.

  • 42.
    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.

  • 43.
    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, p. 228-234Article 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.

  • 44. 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, p. 10078-10091Article 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.

  • 45.
    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, p. 21-28Article 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.

  • 46.
    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, p. 37-45Article 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).

  • 47.
    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, p. 559-566Article 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%).

  • 48.
    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, p. 471-480Article 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.

  • 49.
    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, p. 389-404Article 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.

  • 50.
    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, p. 600-612Article 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.

1234567 1 - 50 of 625
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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
v. 2.34.0
|