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  • 1.
    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.

  • 2.
    Andréasson, Johan
    et al.
    SMHI, Professional Services.
    Hellström, Sara-Sofia
    SMHI, Core Services.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Bergström, Sten
    SMHI, Research Department, Hydrology.
    Översiktlig kartpresentation av klimatförändringars påverkan på Sveriges vattentillgång.: Summary of climate change maps of the Swedish water resources - Background material for the Swedish Commission on Climate and Vulnerability. Underlag till Klimat- och sårbarhetsutredningen.2007Report (Other academic)
    Abstract [en]

    This report summarizes the water resource maps of changes in mean annual runoff, large floods and hydropower potential that have been delivered to the Swedish Commission on Climate and Vulnerability. The hydrological model simulations that have been used to produce the maps were done using the HBV Sweden modelling system. Simulations for present climate used observed input of precipitation and temperature from 1961-1990. Calculations of future hydrological conditions were based on results from regional climate modelling at the Rossby Centre, SMHI. Five different regional scenarios of future climate have been used, four representing the future period 2071-2100 and one for the whole period 1961-2100. Two different approaches to interface the hydrological model and the climate models have been used, the delta method and the scaling method. The mean annual runoff will, according to the scenarios, increase for most parts of Sweden except for the south-east parts of the country. The picture becomes more complex when it comes to changes in large floods, but they are expected to increase substantially in the south-west parts and in the Swedish mountains according to the scenarios. The total Swedish hydropower potential is expected to increase substantially according to the scenarios. All results from HBV Sweden should only be used for a general interpretation of where more in depth analyses might be of interest. The simulations based on the so-called scaling method are more preliminary than the other simulations, since the method is still under development.

  • 3.
    Arheimer, Berit
    et al.
    SMHI, Research Department, Hydrology.
    Lowgren, M
    Pers, Charlotta
    SMHI, Research Department, Hydrology.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Integrated catchment modeling for nutrient reduction: Scenarios showing impacts, potential, and cost of measures2005In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 34, no 7, p. 513-520Article in journal (Refereed)
    Abstract [en]

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

  • 4. Beldring, S.
    et al.
    Andréasson, J.
    Bergström, Sten
    SMHI, Research Department, Hydrology.
    Graham, Phil
    SMHI, Professional Services.
    Jónsdóttir, J. F
    Rogozova, S.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Suomalainen, M.
    Tonning, T.
    Vehviläinen, B.
    Veijalainen, N.
    Mapping water resources in the Nordic region under a changing climate.2006Report (Other academic)
  • 5.
    Donnelly, Chantal
    et al.
    SMHI, Research Department, Hydrology.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Isberg, Kristina
    SMHI, Research Department, Hydrology.
    A validation of river routing networks for catchment modelling from small to large scales2013In: HYDROLOGY RESEARCH, ISSN 1998-9563, Vol. 44, no 5, p. 917-925Article in journal (Refereed)
    Abstract [en]

    Underpinning all hydrological simulations is an estimate of the catchment area upstream of a point of interest. Locally, the delineation of a catchment and estimation of its area is usually done using fine scale maps and local knowledge, but for large-scale hydrological modelling, particularly continental and global scale modelling, this level of detailed data analysis is not practical. For large-scale hydrological modelling, remotely sensed and hydrologically conditioned river routing networks, such as HYDROlk and HydroSHEDS, are often used. This study evaluates the accuracy of the accumulated upstream area in each gridpoint given by the networks. This is useful for evaluating the ability of these data sets to delineate catchments of varying scale for use in hydrological models. It is shown that the higher resolution HydroSHEDS data set gives better results than the HYDROlk data set and that accuracy decreases with decreasing basin scale. In ungauged basins, or where other local catchment area data are not available, the validation made in this study can be used to indicate the likelihood of correctly delineating catchments of different scales using these river routing networks.

  • 6.
    Graham, Phil
    et al.
    SMHI, Research Department, Climate research - Rossby Centre.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Kjellström, Erik
    SMHI, Research Department, Climate research - Rossby Centre.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Hellström, Sara-Sofia
    SMHI, Research Department, Hydrology.
    Berndtsson, Ronny
    Simulating river flow to the Baltic Sea from climate simulations over the past millennium2009In: Boreal environment research, ISSN 1239-6095, E-ISSN 1797-2469, Vol. 14, no 1, p. 173-182Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to reconstruct river flow to the Baltic Sea using data from different periods during the past thousand years. A hydrological model coupled to simulations from climate models was used to estimate river flow. A "millennium" simulation of past climate from the ECHO-G coupled atmosphere-ocean global climate model provided climatological inputs. Results from this global model were downscaled with the RCA3 regional climate model over northern Europe. Temperature and precipitation from the downscaled simulation results were then used in the HBV hydrological model to simulate river flows to the Baltic Sea for the periods 1000-1199 and 1551-1929. These were compared with observations for the period 1921-2002. A general conclusion from this work is that although climate has varied during the past millennium, variability in annual river flow to the Baltic Sea does not appear more pronounced in recent years than during the previous millennium, or vice versa.

  • 7.
    Lindström, Göran
    et al.
    SMHI, Research Department, Hydrology.
    Pers, Charlotta
    SMHI, Research Department, Hydrology.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Strömqvist, Johan
    SMHI, Research Department, Hydrology.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Development and testing of the HYPE (Hydrological Predictions for the Environment) water quality model for different spatial scales2010In: HYDROLOGY RESEARCH, ISSN 1998-9563, Vol. 41, no 3-4, p. 295-319Article in journal (Refereed)
    Abstract [en]

    The HYPE model is a hydrological model for small-scale and large-scale assessments of water resources and water quality, developed at the Swedish Meteorological and Hydrological Institute during 2005-2007. In the model, the landscape is divided into classes according to soil type, land use and altitude. In agricultural lands the soil is divided into three layers, each with individual computations of soil wetness and nutrient processes. The model simulates water flow and transport and turnover of nitrogen and phosphorus. Nutrients follow the same pathways as water in the model: surface runoff, macropore flow, tile drainage and outflow from individual soil layers. Rivers and lakes are described separately with routines for turnover of nutrients in each environment. Model parameters are global, or coupled to soil type or land use. The model was evaluated both by local calibrations to internal variables from different test basins and to data on discharge and nutrients from a large number of small basins. In addition, the estimated parameters were transferred to two larger basins in southern Sweden: River Ronnea and River Vindan. The resulting simulations were generally in good agreement with observations.

  • 8.
    Lindström, Göran
    et al.
    SMHI, Research Department, Hydrology.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Parameter precision in the HBV-NP model and impacts on nitrogen scenario simulations in the Ronnea River, Southern Sweden2005In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 34, no 7, p. 533-537Article in journal (Refereed)
    Abstract [en]

    The HBV-NP model is a newly developed water quality model that describes the turnover and fluxes of both nitrogen and phosphorous. It is based on the conceptual precipitation/runoff HBV model. The HBV-NP model was applied for simulation of nitrogen for the Ronnea catchment in southern Sweden. The catchment was divided into 64 subcatchments in the model. Discharge measurements from six stations and nitrogen measurements from 12 stations were used in the calibration of parameters in the model. Eight automatic calibrations were performed with different combinations of time periods, objective functions, and levels of the nitrogen load in the model. A regionally extended interpretation of the Nash-Sutcliffe R-2 criterion was used in the calibration. In the evaluation of the criterion, the errors were summed over both time steps and sampling points. Scenario simulations of combined measures for reduction of nitrogen load into the sea by 30% were thereafter performed with the eight sets of parameters established by calibration. The model parameters were not uniquely defined by the calibration. However, the simulated relative reduction of nitrogen load into the sea was relatively insensitive to the choice of parameter set, given the available input sources, variables, and data.

  • 9.
    Olsson, Jonas
    et al.
    SMHI, Research Department, Hydrology.
    Graham, Phil
    SMHI, Professional Services.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Hellström, Sara-Sofia
    SMHI, Research Department, Hydrology.
    Kjellström, Erik
    SMHI, Research Department, Climate research - Rossby Centre.
    Berndtsson, Ronny
    Lund University, Department of Water Resources Engineering, .
    Simulation of Runoff in the Baltic Sea Drainage Basin During the Past Millennium2007Conference paper (Other academic)
  • 10.
    Strombäck, Lena
    et al.
    SMHI, Research Department, Hydrology.
    Foster, Kean
    SMHI, Research Department, Hydrology.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Data and Provenance Management for Climate Effect Studies. Adaption of Climate Data with Distribution Based Scaling for Hydrological Simulations.2013In: Proceedings of DBKDA 2013, Seville, Spain., 2013Conference paper (Refereed)
  • 11.
    Wetterhall, Fredrik
    et al.
    SMHI, Research Department, Hydrology.
    Graham, Phil
    SMHI, Research Department, Climate research - Rossby Centre.
    Andreasson, Johan
    SMHI, Professional Services.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Yang, Wei
    SMHI, Research Department, Hydrology.
    Using ensemble climate projections to assess probabilistic hydrological change in the Nordic region2011In: Natural hazards and earth system sciences, ISSN 1561-8633, E-ISSN 1684-9981, Vol. 11, no 8, p. 2295-2306Article in journal (Refereed)
    Abstract [en]

    Assessing hydrological effects of global climate change at local scales is important for evaluating future hazards to society. However, applying climate model projections to local impact models can be difficult as outcomes can vary considerably between different climate models, and including results from many models is demanding. This study combines multiple climate model outputs with hydrological impact modelling through the use of response surfaces. Response surfaces represent the sensitivity of the impact model to incremental changes in climate variables and show probabilies for reaching a priori determined thresholds. Response surfaces were calculated using the HBV hydrological model for three basins in Sweden. An ensemble of future climate projections was then superimposed onto each response surface, producing a probability estimate for exceeding the threshold being evaluated. Site specific impacts thresholds were used where applicable. Probabilistic trends for future change in hazards or potential can be shown and evaluated. It is particularly useful for visualising the range of probable outcomes from climate models and can easily be updated with new results as they are made available.

  • 12.
    Yang, Wei
    et al.
    SMHI, Research Department, Hydrology.
    Andreasson, Johan
    SMHI, Professional Services.
    Graham, Phil
    SMHI, Research Department, Climate research - Rossby Centre.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Rosberg, Jörgen
    SMHI, Research Department, Hydrology.
    Wetterhall, Fredrik
    SMHI, Research Department, Hydrology.
    Distribution-based scaling to improve usability of regional climate model projections for hydrological climate change impacts studies2010In: HYDROLOGY RESEARCH, ISSN 1998-9563, Vol. 41, no 3-4, p. 211-229Article in journal (Refereed)
    Abstract [en]

    As climate change could have considerable influence on hydrology and corresponding water management, appropriate climate change inputs should be used for assessing future impacts. Although the performance of regional climate models (RCMs) has improved over time, systematic model biases still constrain the direct use of RCM output for hydrological impact studies. To address this, a distribution-based scaling (DBS) approach was developed that adjusts precipitation and temperature from RCMs to better reflect observations. Statistical properties, such as daily mean, standard deviation, distribution and frequency of precipitation days, were much improved for control periods compared to direct RCM output. DBS-adjusted precipitation and temperature from two IPCC Special Report on Emissions Scenarios (SRESA1B) transient climate projections were used as inputs to the HBV hydrological model for several river basins in Sweden for the period 1961-2100. Hydrological results using DBS were compared to results with the widely-used delta change (DC) approach for impact studies. The general signal of a warmer and wetter climate was obtained using both approaches, but use of DBS identified differences between the two projections that were not seen with DC. The DBS approach is thought to better preserve the future variability produced by the RCM, improving usability for climate change impact studies.

1 - 12 of 12
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