| 1. |
- Alkan Olsson, Johanna, et al.
(författare)
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A model-supported participatory process for nutrient management: a socio-legal analysis of a bottom-up implementation of the EU Water Framework Directive
- 2011
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Ingår i: International Journal of Agricultural Sustainability. - : Informa UK Limited. - 1473-5903 .- 1747-762X. ; 9:2, s. 379-389
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Tidskriftsartikel (refereegranskat)abstract
- A methodology for local stakeholders' involvement in water management using a catchment model as a platform for dialogue has been developed and tested in the Kaggebo Bay drainage area in the southeast of Sweden. The process involved farmers, rural households not connected to municipal wastewater treatment facilities, local and regional authorities as well as different water and agricultural experts. This paper aims to assess whether and how the methodology has succeeded in encouraging social learning and promoting action and which barriers can be identified. The assessment shows that the methodology is able to create confidence in the process and increase the willingness to act as the methodology was able to adapt the form and content of the dialogue to better fit the cognitive and relational needs of involved stakeholders. It is also shown that the process may lead to a probable improvement of the eutrophication situation. However, if these types of processes are to serve not only as a basis for social learning and action at the local level, but also as the basis for a broader process of societal learning, then a mechanism to confer local ideas to the regional and national levels has to be clarified.
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| 2. |
- Alkan Olsson, Johanna, et al.
(författare)
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How participatory can participatory modeling be? Degrees of influence of stakeholder and expert perspectives in six dimensions of participatory modeling
- 2007
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 56:1, s. 207-214
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Tidskriftsartikel (refereegranskat)abstract
- The authors are involved in a project aiming at the development of a methodology for participatory modeling as a tool for public participation in water resource management. In this paper, some examples of different degrees of stakeholder influence in six key dimensions of participatory modeling are identified and discussed. Arnstein's (A ladder of citizen participation. Journal of the American Institute of Planners, 1969, 4, 216–224) critical discussion of different degrees of “real” decision-making power is taken as a point of departure to assess possible degrees of stakeholder influence. Can we as participatory modelers be sure that we are really inviting our research objects to an equal communicative relationship where local perspectives, knowledge and priorities are respected to the same extent as central and/or expert perspectives? This paper presents an approach that could be used as a tool for structured reflection to avoid unreflective tendencies towards expert knowledge dominance and low degree of stakeholders' real influence over the process.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Andersson, Lotta, et al.
(författare)
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Use of participatory scenario modelling as platforms in stakeholder dialogues
- 2008
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Ingår i: Water S.A.. - 0378-4738 .- 1816-7950. ; 34:4, s. 439-447
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Archfield, Stacey A., et al.
(författare)
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Accelerating advances in continental domain hydrologic modeling
- 2015
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Ingår i: Water resources research. - 0043-1397 .- 1944-7973. ; 51:12, s. 10078-10091
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Arheimer, Berit, et al.
(författare)
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Catchment modelling at the global scale using the World-Wide HYPE (WWH)
- 2019
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Konferensbidrag (refereegranskat)abstract
- Recent advancements in catchment hydrology (such as understanding hydrological processes, accessing new data sources, and refining methods for parameter constraints) make it possible to apply catchment models for ungauged basins over large domains. Here we present a cutting-edge case study applying catchment-modelling techniques at the global scale for the first time. The modelling procedure was challenging but doable and even the first model version show better performance than traditional gridded global models of river flow. We used the open-source code of the HYPE model and applied it for > 130 000 catchments (with an average resolution of 1000 km2), delineated to cover the Earths landmass (except Antarctica). The catchments were characterized using 20 open databases on physiographical variables, to account for spatial and temporal variability of the global freshwater resources, based on exchange with the atmosphere (e.g. precipitation and evapotranspiration) and related budgets in all compartments of the land (e.g. soil, rivers, lakes, glaciers, and floodplains), including water stocks, residence times, interfacial fluxes, and the pathways between various compartments. Global parameter values were estimated using a step-wise approach for groups of parameters regulating specific processes and catchment characteristics in representative gauged catchments. Daily time-series (> 10 years) from 5338 gauges of river flow across the globe were used for model evaluation (half for calibration and half for independent validation), resulting in an average monthly KGE of 0.4. However, the world-wide HYPE (WWH) model shows large variation in model performance, both between geographical domains and between various flow signatures. The model performs best in Eastern USA, Europe, South-East Asia, and Japan, as well as in parts of Russia, Canada, and South America. The model shows overall good potential to capture flow signatures of monthly high flows, spatial variability of high flows, duration of low flows and constancy of daily flow. Nevertheless, there remains large potential for model improvements and we suggest both redoing the calibration and reconsidering parts of the model structure for the next WWH version. The calibration cycle should be repeated a couple of times to find robust values under new fixed parameter conditions. For the next iteration, special focus will be given to precipitation, evapotranspiration, soil storage, and dynamics from hydrological features, such as lakes, reservoirs, glaciers, and floodplains. This first model version clearly indicates challenges in large scale modelling, usefulness of open data and current gaps in processes understanding. Parts of the WWH can be shared with other modellers working at the regional scale to appreciate local knowledge, establish a critical mass of experts and improve the model in a collaborative manner. Setting up a global catchment model has to be a long-term commitment of continuous model refinements to achieve successful and truly useful results.
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| 9. |
- Arheimer, Berit, et al.
(författare)
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Climate change impact on riverine nutrient load and land-based remedial measures of the Baltic sea action plan.
- 2012
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 41:6, s. 600-612
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 10. |
- Arheimer, Berit, et al.
(författare)
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Global catchment modelling usingWorld-Wide HYPE (WWH), open data, and stepwise parameter estimation
- 2020
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Ingår i: Hydrology and Earth System Sciences. - : Copernicus GmbH. - 1027-5606 .- 1607-7938. ; 24:2, s. 535-559
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Tidskriftsartikel (refereegranskat)abstract
- Recent advancements in catchment hydrology (such as understanding catchment similarity, accessing new data sources, and refining methods for parameter constraints) make it possible to apply catchment models for ungauged basins over large domains. Here we present a cutting-edge case study applying catchment-modelling techniques with evaluation against river flow at the global scale for the first time. The modelling procedure was challenging but doable, and even the first model version showed better performance than traditional gridded global models of river flow. We used the open-source code of the HYPE model and applied it for > 130 000 catchments (with an average resolution of 1000 km2), delineated to cover the Earth’s landmass (except Antarctica). The catchments were characterized using 20 open databases on physiographical variables, to account for spatial and temporal variability of the global freshwater resources, based on exchange with the atmosphere (e.g. precipitation and evapotranspiration) and related budgets in all compartments of the land (e.g. soil, rivers, lakes, glaciers, and floodplains), including water stocks, residence times, and the pathways between various compartments. Global parameter values were estimated using a stepwise approach for groups of parameters regulating specific processes and catchment characteristics in representative gauged catchments. Daily and monthly time series (> 10 years) from 5338 gauges of river flow across the globe were used for model evaluation (half for calibration and half for independent validation), resulting in a median monthly KGE of 0.4. However, the World-Wide HYPE (WWH) model shows large variation in model performance, both between geographical domains and between various flow signatures. The model performs best (KGE> 0:6) in the eastern USA, Europe, South-East Asia, and Japan, as well as in parts of Russia, Canada, and South America. The model shows overall good potential to capture flow signatures of monthly high flows, spatial variability of high flows, duration of low flows, and constancy of daily flow. Nevertheless, there remains large potential for model improvements, and we suggest both redoing the parameter estimation and reconsidering parts of the model structure for the next WWH version. This first model version clearly indicates challenges in large-scale modelling, usefulness of open data, and current gaps in process understanding. However, we also found that catchment modelling techniques can contribute to advance global hydrological predictions. Setting up a global catchment model has to be a longterm commitment as it demands many iterations; this paper shows a first version, which will be subjected to continuous model refinements in the future. WWH is currently shared with regional/local modellers to appreciate local knowledge.
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| 11. |
- Arheimer, Berit, et al.
(författare)
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Integrated catchment modeling for nutrient reduction : Scenarios showing impacts, potential, and cost of measures
- 2005
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 34:7, s. 513-520
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Tidskriftsartikel (refereegranskat)abstract
- A hydrological-based model (HBV-NP) was applied to a catchment (1900 km2) in the southern part of Sweden. Careful characterization of the present load situation and the potential for improved treatment or reduced soil leaching were analyzed. Several scenarios were modeled to find strategies to reach the Swedish environmental goals of reducing anthropogenic nitrogen load by 30% and phosphorus load by 20%. It was stated that the goals could be reached by different approaches that would affect different polluters and social sectors. However, no single measure was enough by itself. Instead, a combination of measures was necessary to achieve the goals. The nitrogen goal was the most difficult to attain. In order to be cost-effective, these measures should be applied to areas contributing the most to the net loading of the sea. This strategy could reduce the costs by 70%-80% when compared with implementing the measures in the entire catchment. Integrated catchment models may thus be helpful tools for reducing costs in environmental control programs. © Royal Swedish Academy of Sciences 2005.
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| 12. |
- Arheimer, Berit, et al.
(författare)
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Kväveretention i svenska sjöar och vattendrag – betydelse för utsläpp från reningsverk
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den här rapporten har tagits fram på uppdrag av Naturvårdsverket för att underlättadiskussionen med EU-kommissionen, som har annonserat att den tänker stämma Sverigeinför EU-domstolen för otillräckligt genomförande av avloppsdirektivet. Vidbedömningen av vilka reningsverk som omfattas av krav på kväverening tas i Sverigehänsyn till den naturliga avskiljning (retention) som sker i vattendrag under transportenfrån utsläppskälla till havet.Kväveretention är ett vedertaget begrepp som inkluderar ett flertal naturligabiogeokemiska processer som permanent reducerar kväve från vattenfasen i sjöar ochvattendrag. Speciellt stor är effekten i sjörika områden. Sverige har totalt 92 000 sjöarsom är större än 1 ha. Det är inte ovanligt med 30-70% kväveavskiljning i svenskavattendrag och sjöar. Den process som dominerar avskiljningen i naturen ärdenitrifikation, vilket är samma process som utnyttjas för att avlägsna kväve uravloppsvatten vid reningsverken.Naturlig retention är dock svår att mäta och måste uppskattas med hjälp av antaganden,som så många andra flöden i naturen. I Sverige har man utvecklat ett modellsystem förstorskalig beräkning av närsalttransport, inklusive retention, från land till hav med relativthög geografisk upplösning. Systemet kopplar fältskalemodeller med avrinningsmodeller,är vetenskapligt dokumenterat och granskat och har tillämpats storskaligt sedan 1997 förinternationell rapportering till HELCOM. Avrinningsområdesmodellen (HBV-NP)justeras och utvärderas mot mätningar där sådana finns. Den kväveretention som beräknasmed hjälp av HBV-NP modellen utgörs av kväve som permanent avskiljs till atmosfäroch sediment och som därför inte vidare bidrar till övergödningen av vattensystemen.Både beräkningar och mätningar visar att kväveretentionen är störst på sommaren,speciellt i sjörika områden med hög belastning. Det är stor skillnad i sjöarsretentionskapacitet; i norra delarna av landet är den låg medan sjöarna i de södra delarnaav landet är betydligt effektivare som kvävesänkor. I södra Sverige är medelreduktionen30-40 kg ha-1 sjö år-1. Totalt reduceras ca 30 000 ton kväve per år i sjöar och vattendrag,varav 70% i södra Sverige. För enskilda utsläpp som sker i inlandet reduceras bidraget tillhavet kraftigt under transporten genom vattendrag och sjöar, speciellt för sydcentralaSverige där retentionen i sjöarna är hög. Den ackumulerade effekten kan bli >80%naturlig kväveavskiljning för utsläpp i vissa områden.Det är svårt att utvärdera modellresultaten eftersom inte kväveretentionen går att mätadirekt och retentionen integreras för stora områden och vattendrag. Ofta används andravariabler för att bedöma trovärdigheten i beräkningarna. HBV-NP modellens resultatutvärderas kontinuerligt mot tidsserier av observationer i vattendrag, både för vattenföringoch närsalthalt när den används operationellt. Modellen utvärderas både statistiskt ochvisuellt. Överensstämmelsen med vattenföring och vattenbalans är normalt god, medannärsalthalterna kan avvika en del från uppmätta värden. Känslighetsstudier har visat attmodellen är relativt robust. När modellens resultat jämförs med andra modeller eller enklabudgetberäkningar för sjöar uppstår avvikelser, men dessa kan normalt förklaras av olika2antaganden och indata. Modellen har inte sämre precision än andra motsvarandemodeller, snarare är den något bättre vad gäller vattenföring.När man beräknar hur stor andel av kväveutsläppet från ett enskilt reningsverk som nårhavet ackumuleras retentionen enligt flödesvägarna i landskapet. De reningsverk varsutsläpp passerar fler sjöar får liten påverkan på havet. Naturlig kväveretention ivattendrag och sjöar reducerar de svenska reningsverkens bidrag till kusten med 3200ton/år, vilket motsvarar 18% av reningsverkens totala utsläpp. Retentionen varierar dockbetydligt mellan olika delar av landet. De flesta reningsverk med större utsläpp finnslängs kusten och i södra Sverige, där 90% av retentionen på reningsverksutsläppen sker. INorrlands inland är reningsverken få och retentionen låg, vilket gör att mängden reduceratutsläpp är låg.Allt tyder på att den beräknade kväveretentionen för Sverige är av rätt storleksordningoch att det storskaliga mönstret för Sverige är korrekt, även om avvikelser kanförekomma för enskilda mindre områden och för olika tidsperioder
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| 13. |
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| 14. |
- Arheimer, Berit, 1966-
(författare)
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Riverine nitrogen : Analysis and modelling under Nordic conditions
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Baltic Sea in northern Europe is a brackish water body where eutrophication is considered a serious problem, partly as a result of high nitrogen load from rivers. This thesis includes statistical analysis of nitrogen behaviour in 55 small catchments. The results were used for further development of a dynamic model (HBV-N). This model was then applied in case studies of southern Sweden, including dynamic modelling in 3725 subbasins (totalling 145,000 km2) using time-series from 722 sites. The riverine nitrogen transport to the Swedish coast was simulated. Nitrogen reduction measures within the agricultural sector undertaken during 1985-1994 were found to decrease the normalised load by 7%. Constructed wetlands were found to reduce the load by 16% if 1% of a drainage basin were converted into wetlands. The spatial and temporal variations in terrestrial nitrogen leakage were to a great extent explained by catchment characteristics and hydrometeorological conditions. More detailed studies are needed, however, to distinguish between the influences of the various underlying processes (e.g., flow composition and washout processes). Large-scale studies of nitrogen transport and measure-allocation strategies must consider transformation processes in the aquatic system. The net load was considerably lower than the gross load, and it was temporally and spatially highly variable depending on climate, landscape mosaic, flow path, and watercourses. The HBV-N model is shown to have good potential as a decision-support tool for the improvement of water-quality management and environmental planning under Nordic conditions. For more sophisticated retention modeling, empirical studies are needed to quantify the impact of the various retention processes in the aquatic system.
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| 15. |
- Arheimer, Berit, et al.
(författare)
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The IAHS Science for Solutions decade, with Hydrology Engaging Local People IN a Global world (HELPING)
- 2024
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Ingår i: Hydrological Sciences Journal. - 0262-6667 .- 2150-3435.
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Tidskriftsartikel (refereegranskat)abstract
- The new scientific decade (2023-2032) of the International Association of Hydrological Sciences (IAHS) aims at searching for sustainable solutions to undesired water conditions - may it be too little, too much or too polluted. Many of the current issues originate from global change, while solutions to problems must embrace local understanding and context. The decade will explore the current water crises by searching for actionable knowledge within three themes: global and local interactions, sustainable solutions and innovative cross-cutting methods. We capitalise on previous IAHS Scientific Decades shaping a trilogy; from Hydrological Predictions (PUB) to Change and Interdisciplinarity (Panta Rhei) to Solutions (HELPING). The vision is to solve fundamental water-related environmental and societal problems by engaging with other disciplines and local stakeholders. The decade endorses mutual learning and co-creation to progress towards UN sustainable development goals. Hence, HELPING is a vehicle for putting science in action, driven by scientists working on local hydrology in coordination with local, regional, and global processes.
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| 16. |
- Arheimer, Berit, et al.
(författare)
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Using catchment models to establish measure plans according to the Water Framework Directive
- 2007
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 56:1, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 17. |
- Blösch, Günter, et al.
(författare)
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Twenty-three unsolved problems in hydrology (UPH) - a community perspective
- 2019
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Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 64:10, s. 1141-1158
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Tidskriftsartikel (refereegranskat)abstract
- This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.
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| 18. |
- Capell, Rene, et al.
(författare)
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From local measures to regional impacts : Modelling changes in nutrient loads to the Baltic Sea
- 2021
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Ingår i: Journal of Hydrology. - : Elsevier. - 2214-5818. ; 36
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Tidskriftsartikel (refereegranskat)abstract
- Study Region: Our study region is the Baltic Sea Drainage Basin (BSDB), which covers an area of 1.8 Mio km2 distributed over 14 countries in northern Europe. Study Focus: We use a large-scale hydrological and nutrient transport model (E-HYPE) to model basin-wide impacts of measure scenarios on the Baltic Sea, where eutrophication is a critical issue for the marine ecosystem. We constructed measure scenarios based on stakeholder acceptance, established in workshops in different regions around the Baltic. These measures include local stream reach to catchment scale measures aiming to reduce nutrient transport into the stream network (buffer strips, stormwater ponds) and measures aiming to reduce regional nutrient source releases (fertiliser leaching rates, rural household emissions). New Hydrological Insights for the Region: Nutrient load reductions are often needed to reduce eutrophication and improve overall surface water quality in fresh-water and enclosed bays and seas, where dilution is limited and load emissions have long residence times. To reduce riverine nutrient loads, remediation measures are necessary, e.g. establishment of buffer strips or improved wastewater treatment. Such measures are, however, typically not designed to target nutrient load reductions at sea outlets, but rather focus on local improvements. Here, we show that measures, notwithstanding other meliorating ecosystem benefits, must include reductions in load emissions across large basin areas to impact integrated net loads into coastal sea basins, because reduction measures that only target nutrient delivery to the stream network typically cannot be implemented in a significant enough proportion of the total drainage area of large coastal river basins. Our impact scenarios show BSDB-wide nutrient reductions of up to 9 % for nitrogen and phosphorus compared to a reference scenario, if load emissions are reduced in the scenario assumptions.
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| 19. |
- Crochemore, Louise, et al.
(författare)
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Lessons learnt from checking the quality of openly accessible river flow data worldwide
- 2019
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Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435.
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Tidskriftsartikel (refereegranskat)abstract
- Advances in open data science serve large-scale model developments and, subsequently, hydroclimate services. Local river flow observations are key in hydrology but data sharing remains limited due to unclear quality, or to political, economic or infrastructure reasons. This paper provides methods for quality checking openly accessible river-flow time series. Availability, outliers, homogeneity and trends were assessed in 21 586 time series from 13 data providers worldwide. We found a decrease in data availability since the 1980s, scarce open information in southern Asia, the Middle East and North and Central Africa, and significant river-flow trends in Africa, Australia, southwest Europe and Southeast Asia. We distinguish numerical outliers from high-flow peaks, and to integrate all investigated quality characteristics in a composite indicator. We stress the need to maintain existing gauging networks, and highlight opportunities in extending existing global databases, understanding drivers for trends and inhomogeneity, and in innovative acquisition methods in data-scarce regions.Keywords: open data, river flow, global hydrology, quality control, time series
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| 20. |
- Höltinger, Stefan, et al.
(författare)
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The impact of climatic extreme events on the feasibility of fully renewable power systems : a case study for Sweden
- 2019
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 178, s. 695-713
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Tidskriftsartikel (refereegranskat)abstract
- Long term time series of variable renewable energy (VRE) generation and electricity demand (load) provide important insights into the feasibility of fully renewable power systems. The coverage of energy statistics is usually too short or the temporal resolution too low to study effects related to interannual variability or the impact of climatic extreme events. We use time series simulated from climate data to assess the frequency, duration, and magnitude of extreme residual load events of two fully renewable power scenarios with a share of VRE generation (wind and solar PV) of about 50% for the case of Sweden. We define residual load as load – wind – PV – nuclear generation. Extreme residual load events are events that exceed the balancing or ramping capacities of the current power system. For our analysis, we use 29 years of simulated river runoff and wind and PV generation. Hourly load is derived from MERRA reanalysis temperature data by applying statistical models. Those time series are used along with historic capacity and ramping restrictions of hydro and thermal power plants in an optimization model to minimize extreme residual load events. Our analysis shows that even highly flexible power systems, as the Swedish one, are affected by climatic extreme events if they increase their VRE shares. Replacing current nuclear power capacities by wind power results on average in three extreme residual load events per year that exceed the current power system’s flexibility. Additional PV generation capacities instead of wind increase the number of extreme residual load events by about 4 %, as most events occur during the winter month when solar generation is close to zero and thus not able to counterbalance low wind events. Contrarily, overproduction and the need to curtail VRE generation become more pressing with higher shares of PV. In the discussion we highlight measures that could provide additional balancing capabilities to cope with the more frequent and severe residual load events in a fully renewable power system with high shares of VRE generation.
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| 21. |
- Jaramillo, Fernando, et al.
(författare)
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Dominant effect of increasing forest biomass on evapotranspiration: Interpretations of movement in Budyko space
- 2018
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Ingår i: Hydrology and Earth System Sciences. - : Copernicus GmbH. - 1027-5606 .- 1607-7938. ; 22, s. 567-580
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Tidskriftsartikel (refereegranskat)abstract
- During the last 6 decades, forest biomass has increased in Sweden mainly due to forest management, with a possible increasing effect on evapotranspiration. However, increasing global CO 2 concentrations may also trigger physiological water-saving responses in broadleaf tree species, and to a lesser degree in some needleleaf conifer species, inducing an opposite effect. Additionally, changes in other forest attributes may also affect evapotranspiration. In this study, we aimed to detect the dominating effect(s) of forest change on evapotranspiration by studying changes in the ratio of actual evapotranspiration to precipitation, known as the evaporative ratio, during the period 1961-2012. We first used the Budyko framework of water and energy availability at the basin scale to study the hydroclimatic movements in Budyko space of 65 temperate and boreal basins during this period. We found that movements in Budyko space could not be explained by climatic changes in precipitation and potential evapotranspiration in 60% of these basins, suggesting the existence of other dominant drivers of hydroclimatic change. In both the temperate and boreal basin groups studied, a negative climatic effect on the evaporative ratio was counteracted by a positive residual effect. The positive residual effect occurred along with increasing standing forest biomass in the temperate and boreal basin groups, increasing forest cover in the temperate basin group and no apparent changes in forest species composition in any group. From the three forest attributes, standing forest biomass was the one that could explain most of the variance of the residual effect in both basin groups. These results further suggest that the water-saving response to increasing CO 2 in these forests is either negligible or overridden by the opposite effect of the increasing forest biomass. Thus, we conclude that increasing standing forest biomass is the dominant driver of long-term and large-scale evapotranspiration changes in Swedish forests.
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| 22. |
- Jonsson, Anna, 1967-, et al.
(författare)
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How participatory can participatory modeling be? A discussion of the degree of influence and stakeholder and expert perspectives in six dimensions of participatory modeling
- 2007
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 56:1, s. 207-214
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Tidskriftsartikel (refereegranskat)abstract
- The authors are involved in a project aiming at the development of a methodology for participatory modeling as a tool for public participation in water resource management. In this paper, some examples of different degrees of stakeholder influence in six key dimensions of participatory modeling are identified and discussed. Arnstein's (A ladder of citizen participation. Journal of the American Institute of Planners, 1969, 4, 216–224) critical discussion of different degrees of “real” decision-making power is taken as a point of departure to assess possible degrees of stakeholder influence. Can we as participatory modelers be sure that we are really inviting our research objects to an equal communicative relationship where local perspectives, knowledge and priorities are respected to the same extent as central and/or expert perspectives? This paper presents an approach that could be used as a tool for structured reflection to avoid unreflective tendencies towards expert knowledge dominance and low degree of stakeholders' real influence over the process.
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| 23. |
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| 24. |
- Meier, H. E. Markus, et al.
(författare)
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Ensemble Modeling of the Baltic Sea Ecosystem to Provide Scenarios for Management
- 2014
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 43:1, s. 37-48
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Tidskriftsartikel (refereegranskat)abstract
- We present a multi-model ensemble study for the Baltic Sea, and investigate the combined impact of changing climate, external nutrient supply, and fisheries on the marine ecosystem. The applied regional climate system model contains state-of-the-art component models for the atmosphere, sea ice, ocean, land surface, terrestrial and marine biogeochemistry, and marine food-web. Time-dependent scenario simulations for the period 1960-2100 are performed and uncertainties of future projections are estimated. In addition, reconstructions since 1850 are carried out to evaluate the models sensitivity to external stressors on long time scales. Information from scenario simulations are used to support decision-makers and stakeholders and to raise awareness of climate change, environmental problems, and possible abatement strategies among the general public using geovisualization. It is concluded that the study results are relevant for the Baltic Sea Action Plan of the Helsinki Commission.
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| 25. |
- Meier, Markus, et al.
(författare)
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Comparing reconstructed past variations and future projections of the Baltic sea ecosystem first results from multi model ensemble simulations
- 2012
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 7:3, s. 034005-
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Tidskriftsartikel (refereegranskat)abstract
- Multi-model ensemble simulations for the marine biogeochemistry and food web of the Baltic Sea were performed for the period 1850-2098, and projected changes in the future climate were compared with the past climate environment. For the past period 1850-2006, atmospheric, hydrological and nutrient forcings were reconstructed, based on historical measurements. For the future period 1961-2098, scenario simulations were driven by regionalized global general circulation model (GCM) data and forced by various future greenhouse gas emission and air-and riverborne nutrient load scenarios (ranging from a pessimistic 'business-as-usual' to the most optimistic case). To estimate uncertainties, different models for the various parts of the Earth system were applied. Assuming the IPCC greenhouse gas emission scenarios A1B or A2, we found that water temperatures at the end of this century may be higher and salinities and oxygen concentrations may be lower than ever measured since 1850. There is also a tendency of increased eutrophication in the future, depending on the nutrient load scenario. Although cod biomass is mainly controlled by fishing mortality, climate change together with eutrophication may result in a biomass decline during the latter part of this century, even when combined with lower fishing pressure. Despite considerable shortcomings of state-of-the-art models, this study suggests that the future Baltic Sea ecosystem may unprecedentedly change compared to the past 150 yr. As stakeholders today pay only little attention to adaptation and mitigation strategies, more information is needed to raise public awareness of the possible impacts of climate change on marine ecosystems.
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