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  • 101.
    Donnelly, Chantal
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Rosberg, Jörgen
    SMHI, Forskningsavdelningen, Hydrologi.
    Isberg, Kristina
    SMHI, Forskningsavdelningen, Hydrologi.
    A validation of river routing networks for catchment modelling from small to large scales2013Ingår i: HYDROLOGY RESEARCH, ISSN 1998-9563, Vol. 44, nr 5, s. 917-925Artikel i tidskrift (Refereegranskat)
    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.

  • 102.
    Donnelly, Chantal
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Yang, Wei
    SMHI, Forskningsavdelningen, Hydrologi.
    Dahne, Joel
    SMHI, Affärsverksamhet.
    River discharge to the Baltic Sea in a future climate2014Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 122, nr 1-2, s. 157-170Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study reports on new projections of discharge to the Baltic Sea given possible realisations of future climate and uncertainties regarding these projections. A high-resolution, pan-Baltic application of the Hydrological Predictions for the Environment (HYPE) model was used to make transient simulations of discharge to the Baltic Sea for a mini-ensemble of climate projections representing two high emissions scenarios. The biases in precipitation and temperature adherent to climate models were adjusted using a Distribution Based Scaling (DBS) approach. As well as the climate projection uncertainty, this study considers uncertainties in the bias-correction and hydrological modelling. While the results indicate that the cumulative discharge to the Baltic Sea for 2071 to 2100, as compared to 1971 to 2000, is likely to increase, the uncertainties quantified from the hydrological model and the bias-correction method show that even with a state-of-the-art methodology, the combined uncertainties from the climate model, bias-correction and impact model make it difficult to draw conclusions about the magnitude of change. It is therefore urged that as well as climate model and scenario uncertainty, the uncertainties in the bias-correction methodology and the impact model are also taken into account when conducting climate change impact studies.

  • 103. Eggert, B.
    et al.
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Haerter, J. O.
    Jacob, D.
    Moseley, C.
    Temporal and spatial scaling impacts on extreme precipitation2015Ingår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, nr 10, s. 5957-5971Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Convective and stratiform precipitation events have fundamentally different physical causes. Using a radar composite over Germany, this study separates these precipitation types and compares extremes at different spatial and temporal scales, ranging from 1 to 50 km and 5 min to 6 h, respectively. Four main objectives are addressed. First, we investigate extreme precipitation intensities for convective and stratiform precipitation events at different spatial and temporal resolutions to identify type-dependent space and time reduction factors and to analyze regional and seasonal differences over Germany. We find strong differences between the types, with up to 30% higher reduction factors for convective compared to stratiform extremes, exceeding all other observed seasonal and regional differences within one type. Second, we investigate how the differences in reduction factors affect the contribution of each type to extreme events as a whole, again dependent on the scale and the threshold chosen. A clear shift occurs towards more convective extremes at higher resolution or higher percentiles. For horizontal resolutions of current climate model simulations, i.e., similar to 10 km, the temporal resolution of the data as well as the chosen threshold have profound influence on which type of extreme will be statistically dominant. Third, we compare the ratio of area to duration reduction factor for convective and stratiform events and find that convective events have lower effective advection velocities than stratiform events and are therefore more strongly affected by spatial than by temporal aggregation. Finally, we discuss the entire precipitation distribution regarding data aggregation and identify matching pairs of temporal and spatial resolutions where similar distributions are observed. The information is useful for planning observational networks or storing model data at different temporal and spatial scales.

  • 104. Eisner, S.
    et al.
    Floerke, M.
    Chamorro, A.
    Daggupati, P.
    Donnelly, Chantal
    SMHI, Forskningsavdelningen, Hydrologi.
    Huang, J.
    Hundecha, Yeshewatesfa
    SMHI, Forskningsavdelningen, Hydrologi.
    Koch, H.
    Kalugin, A.
    Krylenko, I.
    Mishra, V.
    Piniewski, M.
    Samaniego, L.
    Seidou, O.
    Wallner, M.
    Krysanova, V.
    An ensemble analysis of climate change impacts on streamflow seasonality across 11 large river basins2017Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 141, nr 3, s. 401-417Artikel i tidskrift (Refereegranskat)
  • 105.
    Eklund, Anna
    et al.
    SMHI, Samhälle och säkerhet.
    Axén Mårtensson, Jenny
    SMHI, Samhälle och säkerhet.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Björck, Emil
    SMHI, Affärsverksamhet.
    Dahné, Joel
    SMHI, Affärsverksamhet.
    Lindström, Lena
    SMHI, Samhälle och säkerhet.
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    Simonsson, Lennart
    SMHI, Forskningsavdelningen, Hydrologi.
    Sjökvist, Elin
    SMHI, Affärsverksamhet.
    Sveriges framtida klimat: Underlag till Dricksvattenutredningen2015Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Det senaste resultatet från klimatforskningen har använts för att producera detaljerade analyser av Sveriges framtida klimat. Resultaten bygger på de klimatscenarier som använts av FN:s klimatpanel i dess femte utvärdering (AR5). I denna analys har två scenarier använts; RCP4.5 som innebär stora framtida utsläppsbegränsningar och RCP8.5 som innebär höga utsläpp av växthusgaser i framtiden. Beräkningar av framtidens klimat och vattentillgång bygger på nytt underlag och delvis nya förutsättningar jämfört med tidigare analyser som presenterats av SMHI. De stora dragen i den beräknade förändringen av nederbörd, temperatur, vattentillgång och flöden kvarstår från tidigare utredningar. Användningen av RCP8.5-scenariet, med sin höga framtida koncentration av växthusgaser, förstärker effekterna jämfört med tidigare publicerade analyser. Eftersom resultaten från FN:s klimatpanel (AR5) presenterades så sent som 2013 så har underlaget framtaget av SMHI präglats av ett intensivt utvecklingsarbete. Resultaten har krävt användande av ny metodik och resultaten kommer även fortsättningsvis att utvärderas av SMHI. Analysen har gjorts för ett antal parametrar som är relevanta för dricksvattenförsörjningen. I tabellen nedan visas en översiktlig sammanfattning av resultaten. Parameter Förändring Lufttemperatur Ökning i hela landet, främst i norra Sverige, främst vintertid. Medelnederbörd Ökning i hela landet, främst i Norrlands inland, främst vinter och vår. Kraftig korttidsnederbörd Ökning i hela landet, främst för de korta varaktigheterna. Vattentillgång Ökning av årsmedel i hela landet förutom östra Götaland. Ökningen är störst på vintern. Minskning på sommaren, främst i östra Götaland. 100-årsflöde och 200-årsflöde Ökning i stora delar av landet. Minskning i Norrlands inland och norra kustland samt nordvästra Svealand Lågflöden Mer vanligt i Götaland och Svealand, främst östra Götaland Havsnivåer Stigande havsnivå, nettoökningen störst i södra Sverige Temperatur Klimatberäkningarna visar på en ökning av årsmedeltemperaturen under innevarande sekel, men med stor spridning av resultaten. Störst beräknas ökningen bli i norr, vilket överensstämmer med tidigare resultat från såväl SMHI som IPCC. Skillnaderna mellan de två utsläppsscenarierna är små för perioden 2021-2050 men ökar mot slutet av århundradet. Scenario RCP4.5 innebär i medeltal en ökning på ca 3 grader till 2100 jämfört med perioden 1961-1990. För RCP8.5 är ökningen större, i medeltal ca 6 grader till 2100. Nederbörd Medelnederbörden beräknas öka i hela landet i framtiden. Störst väntas ökningen bli i Norrlands inland. Skillnaden mellan de två utsläppsscenarierna är små för perioden 2021-2050 men ökar mot slutet av århundradet. En ökning väntas under alla årstider, men främst för vintern och våren. Den extrema korttidsnederbörden beräknas bli mer intensiv i ett framtida klimat. Detta gäller främst skyfall med kort varaktighet. Vattentillgång och flöden I framtiden väntas sett över hela året en ökning av vattentillgången i stora delar av landet, främst i norra Sverige och längs Västkusten. I sydöstra Sverige väntas istället en minskning vilket beror på ökad avdunstning. I större delen av landet väntas vårfloden bli lägre och vinterflödena väntas istället öka. Ändringen i vattentillgång skiljer sig åt mellan olika årstider. Sommartid väntas en minskad vattentillgång i större delen av landet, med den största minskningen i östra Götaland. De extrema flödena väntas i framtiden inträffa mer sällan i Norrlands inland och norra kustland samt nordvästra Svealand. I övriga delar av landet väntas de extrema flödena bli vanligare. De nya beräkningarna visar att en större andel av Sveriges yta kan komma att utsättas för förstärkta extremflöden jämfört med tidigare beräkningar. I framtiden väntas antalet dagar med låga flöden bli fler i Götaland och stora delar av Svealand. Den största förändringen beräknas ske i östra Götaland. Detta är en följd av att avdunstningen ökar till följd av ökad temperatur. Havsnivå Den globala havsnivån väntas stiga i framtiden. En beräknad övre gräns för ökningen är ungefär 1 m till år 2100 enligt IPCC:s senaste utvärdering. Landhöjningen motverkar havsnivåhöjningen, speciellt i norra Sverige.

  • 106. Emerton, Rebecca E.
    et al.
    Stephens, Elisabeth M.
    Pappenberger, Florian
    Pagano, Thomas C.
    Weerts, Albrecht H.
    Wood, Andy W.
    Salamon, Peter
    Brown, James D.
    Hjerdt, Niclas
    SMHI, Samhälle och säkerhet.
    Donnelly, Chantal
    SMHI, Forskningsavdelningen, Hydrologi.
    Baugh, Calum A.
    Cloke, Hannah L.
    Continental and global scale flood forecasting systems2016Ingår i: WILEY INTERDISCIPLINARY REVIEWS-WATER, Vol. 3, nr 3, s. 391-418Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Floods are the most frequent of natural disasters, affecting millions of people across the globe every year. The anticipation and forecasting of floods at the global scale is crucial to preparing for severe events and providing early awareness where local flood models and warning services may not exist. As numerical weather prediction models continue to improve, operational centers are increasingly using their meteorological output to drive hydrological models, creating hydrometeorological systems capable of forecasting river flow and flood events at much longer lead times than has previously been possible. Furthermore, developments in, for example, modelling capabilities, data, and resources in recent years have made it possible to produce global scale flood forecasting systems. In this paper, the current state of operational large-scale flood forecasting is discussed, including probabilistic forecasting of floods using ensemble prediction systems. Six state-of-the-art operational large-scale flood forecasting systems are reviewed, describing similarities and differences in their approaches to forecasting floods at the global and continental scale. Operational systems currently have the capability to produce coarse-scale discharge forecasts in the medium-range and disseminate forecasts and, in some cases, early warning products in real time across the globe, in support of national forecasting capabilities. With improvements in seasonal weather forecasting, future advances may include more seamless hydrological forecasting at the global scale alongside a move towards multi-model forecasts and grand ensemble techniques, responding to the requirement of developing multi-hazard early warning systems for disaster risk reduction. (C) 2016 The Authors. WIREs Water published by Wiley Periodicals, Inc.

  • 107.
    Eriksson, Bertil
    et al.
    SMHI.
    Carlsson, Bengt
    SMHI, Forskningsavdelningen, Hydrologi.
    Dahlström, Bengt
    SMHI, Samhälle och säkerhet.
    Preliminär handledning för korrektion av nederbördsmängder1989Rapport (Övrigt vetenskapligt)
  • 108. Falter, Daniela
    et al.
    Schroeter, Kai
    Dung, Nguyen Viet
    Vorogushyn, Sergiy
    Kreibich, Heidi
    Hundecha, Yeshewatesfa
    SMHI, Forskningsavdelningen, Hydrologi.
    Apel, Heiko
    Merz, Bruno
    Spatially coherent flood risk assessment based on long-term continuous simulation with a coupled model chain2015Ingår i: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 524, s. 182-193Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel approach for assessing flood risk in river catchments in a spatially consistent way is presented. The approach is based on a set of coupled models representing the complete flood risk chain, including a multisite, multivariate weather generator, a hydrological model, a coupled 1D-2D hydrodynamic model and a flood loss model. The approach is exemplarily developed for the meso-scale Mulde catchment in Germany. 10,000 years of meteorological fields at daily resolution are generated and used as input to the subsequent models, yielding 10,000 years of spatially consistent river discharge series, inundation patterns and damage values. This allows estimating flood risk directly from the simulated damage. The benefits of the presented approach are: (1) in contrast to traditional flood risk assessments, where homogenous return periods are assumed for the entire catchment, the approach delivers spatially heterogeneous patterns of precipitation, discharge, inundation and damage patterns which respect the spatial correlations of the different processes and their spatial interactions. (2) Catchment and floodplain processes are represented in a holistic way, since the complete chain of flood processes is represented by the coupled models. For instance, the effects of spatially varying antecedent catchment conditions on flood hydrographs are implicitly taken into account. (3) Flood risk is directly derived from damage yielding a more realistic representation of flood risk. Traditionally, the probability of discharge is used as proxy for the probability of damage. However, non-linearities and threshold behaviour along the flood risk chain contribute to substantial variability between damage probabilities and corresponding discharge probabilities. (C) 2015 Elsevier B.V. All rights reserved.

  • 109. Fosser, G.
    et al.
    Khodayar, S.
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Benefit of convection permitting climate model simulations in the representation of convective precipitation2015Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 44, nr 1-2, s. 45-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A major source of uncertainty in regional climate model (RCM) simulations arises from the parameterisation of sub-grid scale convection. With increasing model resolution, approaching the so-called convection permitting scale, it is possible to switch off most of the convection parameterisations. A set of simulations using COSMO-CLM model has been carried out at different resolutions in order to investigate possible improvements and limitations resulting from increased horizontal resolution. For our analysis, 30 years were simulated in a triple nesting setup with 50, 7 and 2.8 km resolutions, with ERA40 reanalysis data at the lateral boundaries of the coarsest nest. The investigation area covers the state of Baden-Wurttemberg in southwestern Germany, which is a region known for abundant orographically induced convective precipitation. A very dense network of high temporal resolution rain gauges is used for evaluation of the model simulations. The purpose of this study is to examine the differences between the 7 and 2.8 km resolutions in the representation of precipitation at sub-daily timescales, and the atmospheric conditions leading to convection. Our results show that the highest resolution of RCM simulations significantly improves the representation of both hourly intensity distribution and diurnal cycle of precipitation. In addition, at convection permitting scale the atmospheric fields related to convective precipitation show a better agreement with each other. The results imply that higher spatial resolution partially improves the representation of the precipitation field, which must be the way forward for regional climate modelling.

  • 110. Fosser, G.
    et al.
    Khodayar, S.
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Climate change in the next 30 years: What can a convection-permitting model tell us that we did not already know?2017Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 48, nr 5-6, s. 1987-2003Artikel i tidskrift (Refereegranskat)
  • 111.
    Foster, Kean
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Uvo, Cintia Bertacchi
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    The development and evaluation of a hydrological seasonal forecast system prototype for predicting spring flood volumes in Swedish rivers2018Ingår i: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 22, nr 5, s. 2953-2970Artikel i tidskrift (Refereegranskat)
  • 112.
    Gardelin, Marie
    et al.
    SMHI, Affärsverksamhet.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Priestley-Taylor evapotranspiration in HBV-simulations1997Ingår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 28, nr 4-5, s. 233-246Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Estimations of potential evapotranspiration as input to runoff calculations with the HBV model are usually given as monthly standard values calculated with the Penman method. Daily changes in the weather conditions can in later model versions be taken into account by the introduction of a temperature anomaly correction of the evapotranspiration. In this study daily values of potential evapotranspiration calculated with the Priestley-Taylor method were used as input to the model. The required net radiation estimations were calculated from routine weather observations including cloudiness. Potential evapotranspiration was calculated on a three hour basis over a 20-year period. Model simulations using different input data on the potential evapotranspiration were made for three drainage basins (3,500-4,300 km(2)) in Sweden. The Priestley-Taylor evapotranspiration generally gave small improvements of the runoff simulations. The simple temperature anomaly correction method gave improvements of the same size.

  • 113. Gelfan, Alexander
    et al.
    Gustafsson, David
    SMHI, Forskningsavdelningen, Hydrologi.
    Motovilov, Yury
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Kalugin, Andrey
    Krylenko, Inna
    Lavrenov, Alexander
    Climate change impact on the water regime of two great Arctic rivers: modeling and uncertainty issues2017Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 141, nr 3, s. 499-515Artikel i tidskrift (Refereegranskat)
  • 114. Gelfan, Alexander
    et al.
    Gustafsson, David
    SMHI, Forskningsavdelningen, Hydrologi.
    Motovilov, Yury
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Kalugin,, Andrey
    Krylenko,, Inna
    Lavrenov, Alexander
    Climate change impact on the water regime of two great Arctic rivers: modeling and uncertainty issues2016Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, s. 1-17Artikel i tidskrift (Refereegranskat)
  • 115. Gleeson, Tom
    et al.
    Marklund, Lars
    SMHI, Forskningsavdelningen, Hydrologi.
    Smith, Leslie
    Manning, Andrew H.
    Classifying the water table at regional to continental scales2011Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 38, artikel-id L05401Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Water tables at regional to continental scales can be classified into two distinct types: recharge-controlled water tables that are largely disconnected from topography and topography-controlled water tables that are closely tied to topography. We use geomatic synthesis of hydrologic, geologic and topographic data sets to quantify and map water-table type over the contiguous United States using a dimensionless criterion introduced by Haitjema and Mitchell-Bruker (2005), called the water-table ratio, which differentiates water-table type. Our analysis indicates that specific regions of the United States have broadly contiguous and characteristic water-table types. Water-table ratio relates to water-table depth and the potential for regional groundwater flow. In regions with recharge-controlled water tables, for example the Southwest or Rocky Mountains, USA, water-tables depths are generally greater and more variable and regional groundwater flow is generally more important as a percentage of the watershed budget. Water-table depths are generally shallow and less variable, and regional groundwater flow is limited in areas with topography-controlled water tables such as the Northeast USA. The water-table ratio is a simple but powerful criterion for evaluating regional groundwater systems over broad areas. Citation: Gleeson, T., L. Marklund, L. Smith, and A. H. Manning (2011), Classifying the water table at regional to continental scales, Geophys. Res. Lett., 38, L05401, doi: 10.1029/2010GL046427.

  • 116. Gosling, S. N
    et al.
    Zaherpour, J.
    Mount, N.
    Hattermann, F. F.
    Dankers, R.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Breuer, L.
    Ding, J.
    Haddeland, I.
    Kumar, R.
    Kundu, D.
    Liu, J.
    van Griensven, A.
    Veldkamp, T.I.E.
    Vetter, T.
    Wang, X.
    Zhan, X.
    A comparison of changes in river runoff from multiple global and catchment-scale hydrological models under global warming scenarios of 1°C, 2°C and 3°C2016Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, s. 1-19Artikel i tidskrift (Refereegranskat)
  • 117. Gosling, Simon N.
    et al.
    Zaherpour, Jamal
    Mount, Nick J.
    Hattermann, Fred F.
    Dankers, Rutger
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Breuer, Lutz
    Ding, Jie
    Haddeland, Ingjerd
    Kumar, Rohini
    Kundu, Dipangkar
    Liu, Junguo
    van Griensven, Ann
    Veldkamp, Ted I. E.
    Vetter, Tobias
    Wang, Xiaoyan
    Zhang, Xinxin
    A comparison of changes in river runoff from multiple global and catchment-scale hydrological models under global warming scenarios of 1 degrees C, 2 degrees C and 3 degrees C (vol 141, pg 577, 2017)2017Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 141, nr 3, s. 597-598Artikel i tidskrift (Refereegranskat)
  • 118. Gothe, Emma
    et al.
    Friberg, Nikolai
    Kahlert, Maria
    Temnerud, Johan
    SMHI, Forskningsavdelningen, Hydrologi.
    Sandin, Leonard
    Headwater biodiversity among different levels of stream habitat hierarchy2014Ingår i: Biodiversity and Conservation, ISSN 0960-3115, E-ISSN 1572-9710, Vol. 23, nr 1, s. 63-80Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the current loss of biodiversity and threats to freshwater ecosystems, it is crucial to identify hot-spots of biodiversity and on which spatial scale they can be resolved. Conservation and management of these important ecosystems needs insight into whether most of the regional biodiversity (i.e. gamma-diversity) can be found locally (i.e. high alpha-diversity) or whether it is distributed across the region (i.e. high beta-diversity). Biodiversity patterns of benthic macroinvertebrates and diatoms were studied in 30 headwater streams in five Swedish catchments by comparing the relative contribution of alpha- and beta-diversity to gamma-diversity between two levels of stream habitat hierarchy (catchment and region level). The relationship between species community structure and local environmental factors was also assessed. Our results show that both alpha- and beta-diversity made a significant contribution to gamma-diversity. beta-diversity remained relatively constant between the two levels of habitat hierarchy even though local environmental control of the biota decreased from the catchment to the region level. To capture most of headwater gamma-diversity, management should therefore target sites that are locally diverse, but at the same time select sites so that beta-diversity is maximized. As environmental control of the biota peaked at the catchment level, the conservation of headwater stream diversity is likely to be most effective when management targets environmental conditions across multiple local sites within relatively small catchments.

  • 119.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Andersson, Lotta
    SMHI, Samhälle och säkerhet.
    Horan, Mark
    Kunz, Richard
    Lumsden, Trevor
    Schulze, Roland
    Warburton, Michele
    Wilk, Julie
    Yang, Wei
    SMHI, Forskningsavdelningen, Hydrologi.
    Using multiple climate projections for assessing hydrological response to climate change in the Thukela River Basin, South Africa2011Ingår i: Physics and Chemistry of the Earth, ISSN 1474-7065, E-ISSN 1873-5193, Vol. 36, nr 14-15, s. 727-735Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study used climate change projections from different regional approaches to assess hydrological effects on the Thukela River Basin in KwaZulu-Natal, South Africa. Projecting impacts of future climate change onto hydrological systems can be undertaken in different ways and a variety of effects can be expected. Although simulation results from global climate models (GCMs) are typically used to project future climate, different outcomes from these projections may be obtained depending on the GCMs themselves and how they are applied, including different ways of downscaling from global to regional scales. Projections of climate change from different downscaling methods, different global climate models and different future emissions scenarios were used as input to simulations in a hydrological model to assess climate change impacts on hydrology. A total of 10 hydrological change simulations were made, resulting in a matrix of hydrological response results. This matrix included results from dynamically downscaled climate change projections from the same regional climate model (RCM) using an ensemble of three GCMs and three global emissions scenarios, and from statistically downscaled projections using results from five GCMs with the same emissions scenario. Although the matrix of results does not provide complete and consistent coverage of potential uncertainties from the different methods, some robust results were identified. In some regards, the results were in agreement and consistent for the different simulations. For others, particularly rainfall, the simulations showed divergence. For example, all of the statistically downscaled simulations showed an annual increase in precipitation and corresponding increase in river runoff, while the RCM downscaled simulations showed both increases and decreases in runoff. According to the two projections that best represent runoff for the observed climate, increased runoff would generally be expected for this basin in the future. Dealing with such variability in results is not atypical for assessing climate change impacts in Africa and practitioners are faced with how to interpret them. This work highlights the need for additional, well-coordinated regional climate downscaling for the region to further define the range of uncertainties involved. (C) 2011 Elsevier Ltd. All rights reserved.

  • 120.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Andreasson, Johan
    SMHI, Affärsverksamhet.
    Carlsson, Bengt
    SMHI, Forskningsavdelningen, Hydrologi.
    Assessing climate change impacts on hydrology from an ensemble of regional climate models, model scales and linking methods - a case study on the Lule River basin2007Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 81, s. 293-307Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper investigates how using different regional climate model (RCM) simulations affects climate change impacts on hydrology in northern Europe using an offline hydrological model. Climate change scenarios from an ensemble of seven RCMs, two global climate models (GCMs), two global emissions scenarios and two RCMs of varying resolution were used. A total of 15 climate change simulations were included in studies on the Lule River basin in Northern Sweden. Two different approaches to transfer climate change from the RCMs to hydrological models were tested. A rudimentary estimate of change in laydropower potential on the Lule River due to climate change was also made. The results indicate an overall increase in river flow, earlier spring peak flows and an increase in hydropower potential. The two approaches for transferring the signal of climate change to the hydrological impacts model gave similar mean results, but considerably different seasonal dynamics, a result that is highly relevant for other types of climate change impacts studies.

  • 121.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Land surface modelling in hydrology and meteorology - lessons learned from the Baltic Basin2000Ingår i: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 4, nr 1, s. 13-22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    By both tradition and purpose, the land parameterization schemes of hydrological and meteorological models differ greatly. Meteorologists are concerned primarily with solving the energy balance, whereas hydrologists are most interested in the water balance. Meteorological climate models typically have multi-layered soil parameterisation that solves temperature fluxes numerically with diffusive equations. The same approach is carried over to a similar treatment of water transport. Hydrological models are not usually so interested in soil temperatures, but must provide a reasonable representation of soil moisture to get runoff right. To treat the heterogeneity of the soil, many hydrological models use only one laver with a statistical representation of soil variability. Such a hydrological model can be used on large scales while taking subgrid variability into account. Hydrological models also include lateral transport of water - an imperative if river discharge is to be estimated. The concept of a complexity chain for coupled modelling systems is introduced, together with considerations for mixing model components. Under BALTEX (Baltic Sea Experiment) and SWECLIM (Swedish Regional Climate Modelling Programme), a large-scale hydrological model of runoff in the Baltic Basin is used to review atmospheric climate model simulations. This incorporates both the runoff record and hydrological modelling experience into atmospheric model development. Results from two models are shown. A conclusion is that the key to improved models may be less complexity. Perhaps the meteorological models should keep their multi-layered approach for modelling soil temperature, bur add a simpler, yet physically consistent, hydrological approach for modelling snow processes and water transport in the soil.

  • 122.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Water balance modelling in the Baltic Sea drainage basin - analysis of meteorological and hydrological approaches2001Ingår i: Meteorology and atmospheric physics (Print), ISSN 0177-7971, E-ISSN 1436-5065, Vol. 77, nr 1-4, s. 45-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Efforts to understand and simulate the global climate in numerical models have led to regional studies of the energy and water balance. The Baltic Basin provides a continental scale test basin where meteorology, oceanography and hydrology all can meet. Using a simple conceptual approach, a large-scale hydrological model of the water balance of the total Baltic Sea Drainage Basin (HBV-Baltic) was used to simulate the basinwide water balance components for the present climate and to evaluate the land surface components of atmospheric climate models. It has been used extensively in co-operative BALTEX (The Baltic Sea Experiment) research and within SWECLIM (Swedish Regional Climate Modelling Programme) to support continued regional climate model development. This helps to identify inconsistencies in bath meteorological and hydrological models. One result is that compensating errors are evident in the snow routines of the atmospheric models studied. The use of HBV-Baltic has greatly improved the dialogue between hydrological and meteorological modellers within the Baltic Basin research community. It is concluded that conceptual hydrological models, although far from being complete, play an important role in the realm of continental scale hydrological modelling. Atmospheric models benefit from the experience of hydrological modellers in developing simpler, yet more effective land surface parameterisations. This basic modelling tool for simulating the large-scale water balance of the Baltic Sea drainage basin is the only existing hydrological model that covers the entire basin and will continue to be used until more detailed models can be successfully applied at this scale.

  • 123.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Rosberg, Jörgen
    SMHI, Forskningsavdelningen, Hydrologi.
    Hellström, Sara-Sofia
    SMHI, Forskningsavdelningen, Hydrologi.
    Berndtsson, Ronny
    Simulating river flow to the Baltic Sea from climate simulations over the past millennium2009Ingår i: Boreal environment research, ISSN 1239-6095, E-ISSN 1797-2469, Vol. 14, nr 1, s. 173-182Artikel i tidskrift (Refereegranskat)
    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.

  • 124. Grahn, T.
    et al.
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    Insured flood damage in Sweden, 1987-20132019Ingår i: Journal of Flood Risk Management, ISSN 1753-318X, E-ISSN 1753-318X, Vol. 12, nr 3, artikel-id UNSP e12465Artikel i tidskrift (Refereegranskat)
  • 125. Grimvall, Anders
    et al.
    von Bromssen, Claudia
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Using process-based models to filter out natural variability in observed concentrations of nitrogen and phosphorus in river water2014Ingår i: Environmental Monitoring & Assessment, ISSN 0167-6369, E-ISSN 1573-2959, Vol. 186, nr 8, s. 5135-5152Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Advances in process-based modelling of loads of nitrogen and phosphorus carried by rivers have created new possibilities to interpret time series of water quality data. We examined how model runs with constant anthropogenic forcing can be used to estimate and filter out weather-driven variation in observational data and, thereby, draw attention to other features of such data. An assessment of measured and modelled nutrient concentrations at the outlets of 45 Swedish rivers provided promising results for total nitrogen. In particular, joint analyses of observational data and outputs from the catchment model S-HYPE strengthened the evidence that downward trends in nitrogen were due to mitigation measures in agriculture. Evaluation of modelled and observed total phosphorus concentrations revealed considerable bias in the collection or chemical analysis of water samples and also identified weaknesses in the model outputs. Together, our results highlight the need for more efficient two-way communication between environmental modelling and monitoring.

  • 126. Gutierrez, J. M.
    et al.
    Maraun, D.
    Widmann, M.
    Huth, R.
    Hertig, E.
    Benestad, R.
    Roessler, O.
    Wibig, J.
    Wilcke, Renate
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Kotlarski, S.
    San Martin, D.
    Herrera, S.
    Bedia, J.
    Casanueva, A.
    Manzanas, R.
    Iturbide, M.
    Vrac, M.
    Dubrovsky, M.
    Ribalaygua, J.
    Portoles, J.
    Raty, O.
    Raisanen, J.
    Hingray, B.
    Raynaud, D.
    Casado, M. J.
    Ramos, P.
    Zerenner, T.
    Turco, M.
    Bosshard, Thomas
    SMHI, Forskningsavdelningen, Hydrologi.
    Stepanek, P.
    Bartholy, J.
    Pongracz, R.
    Keller, D. E.
    Fischer, A. M.
    Cardoso, R. M.
    Soares, P. M. M.
    Czernecki, B.
    Page, C.
    An intercomparison of a large ensemble of statistical downscaling methods over Europe: Results from the VALUE perfect predictor cross-validation experiment2019Ingår i: International Journal of Climatology, ISSN 0899-8418, E-ISSN 1097-0088, Vol. 39, nr 9, s. 3750-3785Artikel i tidskrift (Refereegranskat)
  • 127. Haerter, Jan O.
    et al.
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Moseley, Christopher
    Precipitation onset as the temporal reference in convective self-organization2017Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 44, nr 12, s. 6450-6459Artikel i tidskrift (Refereegranskat)
  • 128. Haerter, Jan O.
    et al.
    Eggert, Bastian
    Moseley, Christopher
    Piani, Claudio
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Statistical precipitation bias correction of gridded model data using point measurements2015Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 42, nr 6, s. 1919-1929Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is well known that climate model output data cannot be used directly as input to impact models, e.g., hydrology models, due to climate model errors. Recently, it has become customary to apply statistical bias correction to achieve better statistical correspondence to observational data. As climate model output should be interpreted as the space-time average over a given model grid box and output time step, the status quo in bias correction is to employ matching gridded observational data to yield optimal results. Here we show that when gridded observational data are not available, statistical bias correction can be carried out using point measurements, e.g., rain gauges. Our nonparametric method, which we call scale-adapted statistical bias correction (SABC), is achieved by data aggregation of either the available modeled or gauge data. SABC is a straightforward application of the well-known Taylor hypothesis of frozen turbulence. Using climate model and rain gauge data, we show that SABC performs significantly better than equal-time period statistical bias correction.

  • 129. Hall, J.
    et al.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Aronica, T.
    Bilibashi, A.
    Bohac, M.
    Bonacci, O.
    Borga, M.
    Burlando, P.
    Castellarin, A.
    Chirico, G. B.
    Claps, P.
    Fiala, K.
    Gaal, L.
    Gorbachova, L.
    Gul, A.
    Hannaford, J.
    Kiss, A.
    Kjeldsen, T.
    Kohnova, S.
    Koskela, J. J.
    Macdonald, N.
    Mavrova-Guirguinova, M.
    Ledvinka, O.
    Mediero, L.
    Merz, B.
    Merz, R.
    Molnar, P.
    Montanari, A.
    Osuch, M.
    Parajka, J.
    Perdigao, R. A. P.
    Radevski, I.
    Renard, B.
    Rogger, M.
    Salinas, J. L.
    Sauquet, E.
    Sraj, M.
    Szolgay, J.
    Viglione, A.
    Volpi, E.
    Wilson, D.
    Zaimi, K.
    Bloeschl, G.
    A European Flood Database: facilitating comprehensive flood research beyond administrative boundaries2015Ingår i: CHANGES IN FLOOD RISK AND PERCEPTION IN CATCHMENTS AND CITIES, 2015, s. 89-95Konferensbidrag (Refereegranskat)
    Abstract [en]

    The current work addresses one of the key building blocks towards an improved understanding of flood processes and associated changes in flood characteristics and regimes in Europe: the development of a comprehensive, extensive European flood database. The presented work results from ongoing cross-border research collaborations initiated with data collection and joint interpretation in mind. A detailed account of the current state, characteristics and spatial and temporal coverage of the European Flood Database, is presented. At this stage, the hydrological data collection is still growing and consists at this time of annual maximum and daily mean discharge series, from over 7000 hydrometric stations of various data series lengths. Moreover, the database currently comprises data from over 50 different data sources. The time series have been obtained from different national and regional data sources in a collaborative effort of a joint European flood research agreement based on the exchange of data, models and expertise, and from existing international data collections and open source websites. These ongoing efforts are contributing to advancing the understanding of regional flood processes beyond individual country boundaries and to a more coherent flood research in Europe.

  • 130. Hall, J.
    et al.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Borga, M.
    Brazdil, R.
    Claps, P.
    Kiss, A.
    Kjeldsen, T. R.
    Kriauciuniene, J.
    Kundzewicz, Z. W.
    Lang, M.
    Llasat, M. C.
    Macdonald, N.
    McIntyre, N.
    Mediero, L.
    Merz, B.
    Merz, R.
    Molnar, P.
    Montanari, A.
    Neuhold, C.
    Parajka, J.
    Perdigao, R. A. P.
    Plavcova, L.
    Rogger, M.
    Salinas, J. L.
    Sauquet, E.
    Schaer, C.
    Szolgay, J.
    Viglione, A.
    Bloeschl, G.
    Understanding flood regime changes in Europe: a state-of-the-art assessment2014Ingår i: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 18, nr 7, s. 2735-2772Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is growing concern that flooding is becoming more frequent and severe in Europe. A better understanding of flood regime changes and their drivers is therefore needed. The paper reviews the current knowledge on flood regime changes in European rivers that has traditionally been obtained through two alternative research approaches. The first approach is the data-based detection of changes in observed flood events. Current methods are reviewed together with their challenges and opportunities. For example, observation biases, the merging of different data sources and accounting for nonlinear drivers and responses. The second approach consists of modelled scenarios of future floods. Challenges and opportunities associated with flood change scenarios are discussed such as fully accounting for uncertainties in the modelling cascade and feedbacks. To make progress in flood change research, we suggest that a synthesis of these two approaches is needed. This can be achieved by focusing on long duration records and flood-rich and flood-poor periods rather than on short duration flood trends only, by formally attributing causes of observed flood changes, by validating scenarios against observed flood regime dynamics, and by developing low-dimensional models of flood changes and feedbacks. The paper finishes with a call for a joint European flood change research network.

  • 131. Hankin, Barry
    et al.
    Strömqvist, Johan
    SMHI, Forskningsavdelningen, Hydrologi.
    Burgess, Chris
    Pers, Charlotta
    SMHI, Forskningsavdelningen, Hydrologi.
    Bielby, Sally
    Revilla-Romero, Beatriz
    Pope, Linda
    A New National Water Quality Model to Evaluate the Effectiveness of Catchment Management Measures in England2019Ingår i: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 11, nr 8, artikel-id 1612Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This investigation reports on a new national model to evaluate the effectiveness of catchment sensitive farming in England, and how pollution mitigation measures have improved water quality between 2006 and 2016. An adapted HYPE (HYdrological Predictions for the Environment) model was written to use accurate farm emissions data so that the pathway impact could be accounted for in the land phase of transport. Farm emissions were apportioned into different runoff fractions simulated in surface and soil layers, and travel time and losses were taken into account. These were derived from the regulator's catchment change matrix' and converted to monthly load time series, combined with extensive point source load datasets. Very large flow and water quality monitoring datasets were used to calibrate the model nationally for flow, nitrogen, phosphorus, suspended sediments and faecal indicator organisms. The model was simulated with and without estimated changes to farm emissions resulting from catchment measures, and spatial and temporal changes to water quality concentrations were then assessed.

  • 132. Hansen, A. L.
    et al.
    Donnelly, Chantal
    SMHI, Forskningsavdelningen, Hydrologi.
    Refsgaard, J. C.
    Karlsson, I. B.
    Simulation of nitrate reduction in groundwater - An upscaling approach from small catchments to the Baltic Sea basin2018Ingår i: Advances in Water Resources, ISSN 0309-1708, E-ISSN 1872-9657, Vol. 111, s. 58-69Artikel i tidskrift (Refereegranskat)
  • 133.
    Harlin, Joakim
    et al.
    SMHI.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Sundby, Mikael
    SMHI.
    Brandesten, Claes-Olof
    Vattenfall Hydropower AB.
    Känslighetsanalys av Flödeskommitténs riktlinjer för dimensionering av hel älv1992Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    En känslighetsanalys av Flödeskommittens riktlinjer för beräkning av dimensionerande

    flöden tillämpade på flermagasinssystemet i Ljusnan redovisas. Simuleringarna har gjorts med hjälp av ett modell.system baserat på HBV-modellen, som kompletterats med regleringsstrategier. Det 14 560 km 2 stora avrinningsområdet delades in i 16 delområden. Vid tre kraftverksdammar studerades känsligheten hos de dimensionerande vattennivåerna med hänsyn tagen till ändringar i de föreskrivna riktlinjerna, regleringsstrategier

    och modellparametrar. Förändringar i den dimensionerande nederbörden, snömagasinet

    eller utskovskapaciteten hade betydande inverkan på högsta vattenståndet i alla tre

    magasinen. Ändringar i regleringsstrategierna hade mindre effekt. Den högsta recessionsparametern i HBV-modellen,

    Ko, hade stor inverkan på de dimensionerande vattennivåerna. Efter det att magasinet fyllts, syntes ett klart samband mellan högsta tillrinning och maximal vattennivå. Studien visar, att det är svårt att förutbestämma den integrerade effekten av extrem nederbörd, snösmältning, markfuktighetstillstånd och reglering i ett system.

  • 134. Hattermann, F. F.
    et al.
    Krysanova, V.
    Gosling, S. N.
    Dankers, R.
    Daggupati, P.
    Donnelly, Chantal
    SMHI, Forskningsavdelningen, Hydrologi.
    Floerke, M.
    Huang, S.
    Motovilov, Y.
    Buda, S.
    Yang, T.
    Mueller, C.
    Leng, G.
    Tang, Q.
    Portmann, F. T.
    Hagemann, S.
    Gerten, D.
    Wada, Y.
    Masaki, Y.
    Alemayehu, T.
    Satoh, Y.
    Samaniego, L.
    Cross-scale intercomparison of climate change impacts simulated by regional and global hydrological models in eleven large river basins2017Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 141, nr 3, s. 561-576Artikel i tidskrift (Refereegranskat)
  • 135. Hattermann, F. F.
    et al.
    Vetter, T.
    Breuer, L.
    Su, Buda
    Daggupati, P.
    Donnelly, Chantal
    SMHI, Forskningsavdelningen, Hydrologi.
    Fekete, B.
    Floerke, F.
    Gosling, S. N.
    Hoffmann, P.
    Liersch, S.
    Masaki, Y.
    Motovilov, Y.
    Mueller, C.
    Samaniego, L.
    Stacke, T.
    Wada, Y.
    Yang, T.
    Krysnaova, V.
    Sources of uncertainty in hydrological climate impact assessment: a cross-scale study2018Ingår i: Environmental Research Letters, ISSN 1748-9326, E-ISSN 1748-9326, Vol. 13, nr 1, artikel-id 015006Artikel i tidskrift (Refereegranskat)
  • 136. Hejzlar, J.
    et al.
    Anthony, S.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Behrendt, H.
    Bouraoui, F.
    Grizzetti, B.
    Groenendijk, P.
    Jeuken, M. H. J. L.
    Johnsson, H.
    Lo Porto, A.
    Kronvang, B.
    Panagopoulos, Y.
    Siderius, C.
    Silgram, M.
    Venohr, M.
    Zaloudik, J.
    Nitrogen and phosphorus retention in surface waters: an inter-comparison of predictions by catchment models of different complexity2009Ingår i: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 11, nr 3, s. 584-593Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nitrogen and phosphorus retention estimates in streams and standing water bodies were compared for four European catchments by a series of catchment-scale modelling tools of different complexity, ranging from a simple, equilibrium input-output type to dynamic, physical-based models: source apportionment, MONERIS, EveNFlow, TRK, SWAT, and NL-CAT. The four catchments represent diverse climate, hydrology, and nutrient loads from diffuse and point sources in Norway, the UK, Italy, and the Czech Republic. The models' retention values varied largely, with tendencies towards higher scatters for phosphorus than for nitrogen, and for catchments with lakes (Vansjo-Hobol, Z. elivka) compared to mostly or entirely lakeless catchments (Ouse or Enza, respectively). A comparison of retention values with the size of nutrient sources showed that the modelled nutrient export from diffuse sources was directly proportional to retention estimates, hence implying that the uncertainty in quantification of diffuse catchment sources of nutrients was also related to the uncertainty in nutrient retention determination. This study demonstrates that realistic modelling of nutrient export from large catchments is very difficult without a certain level of measured data. In particular, even complex process oriented models require information on the retention capabilities of water bodies within the receiving surface water system and on the nutrient export from micro-catchments representing the major types of diffuse sources to surface waters.

  • 137.
    Hellström, Sara-Sofia
    et al.
    SMHI, Samhälle och säkerhet.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Regional analys av klimat, vattentillgång och höga flöden2008Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Rapporten beskriver långtidsvariationen i nederbörd, temperatur, vattentillgång och höga flöden i Sverige, med särskilt tonvikt på frågeställningar av betydelse för vattenkraftindustrin.Utgångspunkten för studien är regionala serier för nederbörd, temperatur och avrinning för tillrinningsområdena till de fyra havsbassängerna i Östersjön och Västerhavet: Bottenviken, Bottenhavet, Egentliga Östersjön och Västerhavet.

  • 138. Helmert, Juergen
    et al.
    Lange, Martin
    Dong, Jiarui
    De Rosnay, Patricia
    Gustafsson, David
    SMHI, Forskningsavdelningen, Hydrologi.
    Churulin, Evgeniy
    Kurzeneva, Ekaterina
    Mueller, Richard
    Trentmann, Joerg
    Souverijns, Niels
    Koch, Roland
    Boehm, Uwe
    Bartik, Martin
    Osuch, Marzena
    Rozinkina, Inna
    Bettems, Jean-Marie
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Marcucci, Francesca
    Milelli, Massimo
    1st Snow Data Assimilation Workshop in the framework of COST HarmoSnow ESSEM 14042018Ingår i: Meteorologische Zeitschrift, ISSN 0941-2948, E-ISSN 1610-1227, Vol. 27, nr 4, s. 325-333Artikel i tidskrift (Refereegranskat)
  • 139. Hoeltinger, Stefan
    et al.
    Mikovits, Christian
    Schmidt, Johannes
    Baumgartner, Johann
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Wetterlund, Elisabeth
    The impact of climatic extreme events on the feasibility of fully renewable power systems: A case study for Sweden2019Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 178, s. 695-713Artikel i tidskrift (Refereegranskat)
  • 140. Hojberg, Anker Lajer
    et al.
    Hansen, Anne Lausten
    Wachniew, Przemyslaw
    Zurek, Anna J.
    Virtanen, Seija
    Arustiene, Jurga
    Strömqvist, Johan
    SMHI, Forskningsavdelningen, Hydrologi.
    Rankinen, Katri
    Refsgaard, Jens Christian
    Review and assessment of nitrate reduction in groundwater in the Baltic Sea Basin2017Ingår i: JOURNAL OF HYDROLOGY-REGIONAL STUDIES, ISSN 2214-5818, Vol. 12, s. 50-68Artikel i tidskrift (Refereegranskat)
  • 141. Hrachowitz, M.
    et al.
    Savenije, H. H. G.
    Bloeschl, G.
    McDonnell, J. J.
    Sivapalan, M.
    Pomeroy, J. W.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Blume, T.
    Clark, M. P.
    Ehret, U.
    Fenicia, F.
    Freer, J. E.
    Gelfan, A.
    Gupta, H. V.
    Hughes, D. A.
    Hut, R. W.
    Montanari, A.
    Pande, S.
    Tetzlaff, D.
    Troch, P. A.
    Uhlenbrook, S.
    Wagener, T.
    Winsemius, H. C.
    Woods, R. A.
    Zehe, E.
    Cudennec, C.
    A decade of Predictions in Ungauged Basins (PUB)a review2013Ingår i: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 58, nr 6, s. 1198-1255Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Prediction in Ungauged Basins (PUB) initiative of the International Association of Hydrological Sciences (IAHS), launched in 2003 and concluded by the PUB Symposium 2012 held in Delft (23-25 October 2012), set out to shift the scientific culture of hydrology towards improved scientific understanding of hydrological processes, as well as associated uncertainties and the development of models with increasing realism and predictive power. This paper reviews the work that has been done under the six science themes of the PUB Decade and outlines the challenges ahead for the hydrological sciences community.

  • 142. Huang, Shaochun
    et al.
    Kumar, Rohini
    Floerke, Martina
    Yang, Tao
    Hundecha, Yeshewatesfa
    SMHI, Forskningsavdelningen, Hydrologi.
    Kraft, Philipp
    Gao, Chao
    Gelfan, Alexander
    Liersch, Stefan
    Lobanova, Anastasia
    Strauch, Michael
    van Ogtrop, Floris
    Reinhardt, Julia
    Haberlandt, Uwe
    Krysanova, Valentina
    Evaluation of an ensemble of regional hydrological models in 12 large-scale river basins worldwide2017Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 141, nr 3, s. 381-397Artikel i tidskrift (Refereegranskat)
  • 143. Huang, Shaochun
    et al.
    Kumar, Rohini
    Floerke, Martina
    Yang, Tao
    Hundecha, Yeshewatesfa
    SMHI, Forskningsavdelningen, Hydrologi.
    Kraft, Philipp
    Gao, Chao
    Gelfan, Alexander
    Liersch, Stefan
    Lobanova, Anastasia
    Strauch, Michael
    van Ogtrop, Floris
    Reinhardt, Julia
    Haberlandt, Uwe
    Krysanova, Valentina
    Evaluation of an ensemble of regional hydrological models in 12 large-scale river basins worldwide (vol 141, pg 381, 2017)2017Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 141, nr 3, s. 399-400Artikel i tidskrift (Refereegranskat)
  • 144. Huisman, J. A.
    et al.
    Breuer, L.
    Bormann, H.
    Bronstert, A.
    Croke, B. F. W.
    Frede, H. -G
    Graeff, T.
    Hubrechts, L.
    Jakeman, A. J.
    Kite, G.
    Lanini, J.
    Leavesley, G.
    Lettenmaier, D. P.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Seibert, J.
    Sivapalan, M.
    Viney, N. R.
    Willems, P.
    Assessing the impact of land use change on hydrology by ensemble modeling (LUCHEM) III: Scenario analysis2009Ingår i: Advances in Water Resources, ISSN 0309-1708, E-ISSN 1872-9657, Vol. 32, nr 2, s. 159-170Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An ensemble of 10 hydrological models was applied to the same set of land use change scenarios. There was general agreement about the direction of changes in the mean annual discharge and 90% discharge percentile predicted by the ensemble members, although a considerable range in the magnitude of predictions for the scenarios and catchments under consideration was obvious. Differences in the magnitude of the increase were attributed to the different mean annual actual evapotranspiration rates for each land use type. The ensemble of model runs was further analyzed with deterministic and probabilistic ensemble methods. The deterministic ensemble method based on a trimmed mean resulted in a single somewhat more reliable scenario prediction. The probabilistic reliability ensemble averaging (REA) method allowed a quantification of the model structure uncertainty in the scenario predictions. It was concluded that the use of a model ensemble has greatly increased our confidence in the reliability of the model predictions. (C) 2008 Elsevier Ltd. All rights reserved.

  • 145.
    Hundecha, Yeshewatesfa
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Donnelly, Chantal
    SMHI, Forskningsavdelningen, Hydrologi.
    Pechlivanidis, Ilias
    SMHI, Forskningsavdelningen, Hydrologi.
    A regional parameter estimation scheme for a pan-European multi-basin model.2016Ingår i: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 6, s. 90-111Artikel i tidskrift (Refereegranskat)
  • 146.
    Hundecha, Yeshewatesfa
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Sunyer, Maria A.
    Lawrence, Deborah
    Madsen, Henrik
    Willems, Patrick
    Buerger, Gerd
    Kriauciuniene, Jurate
    Loukas, Athanasios
    Martinkova, Marta
    Osuch, Marzena
    Vasiliades, Lampros
    von Christierson, Birgitte
    Vormoor, Klaus
    Yuecel, Ismail
    Inter-comparison of statistical downscaling methods for projection of extreme flow indices across Europe2016Ingår i: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 541, s. 1273-1286Artikel i tidskrift (Refereegranskat)
  • 147. Hutton, Christopher
    et al.
    Wagener, Thorsten
    Freer, Jim
    Han, Dawei
    Duffy, Chris
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Most computational hydrology is not reproducible, so is it really science?2016Ingår i: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 52, nr 10, s. 7548-7555Artikel i tidskrift (Refereegranskat)
  • 148. Hutton, Christopher
    et al.
    Wagener, Thorsten
    Freer, Jim
    Han, Dawei
    Duffy, Chris
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Reply to comment by Anel on "Most computational hydrology is not reproducible, so is it really science?"2017Ingår i: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 53, nr 3, s. 2575-2576Artikel i tidskrift (Refereegranskat)
  • 149. Hutton, Christopher
    et al.
    Wagener, Thorsten
    Freer, Jim
    Han, Dawei
    Duffy, Chris
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Reply to comment by Melsen et al. on "Most computational hydrology is not reproducible, so is it really science?"2017Ingår i: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 53, nr 3, s. 2570-2571Artikel i tidskrift (Refereegranskat)
  • 150. Hytteborn, Julia K.
    et al.
    Temnerud, Johan
    SMHI, Forskningsavdelningen, Hydrologi.
    Alexander, Richard B.
    Boyer, Elizabeth W.
    Futter, Martyn N.
    Froberg, Mats
    Dahne, Joel
    SMHI, Affärsverksamhet.
    Bishop, Kevin H.
    Patterns and predictability in the intra-annual organic carbon variability across the boreal and hemiboreal landscape2015Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 520, s. 260-269Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Factors affecting total organic carbon (TOC) concentrations in 215 watercourses across Sweden were investigated using parameter parsimonious regression approaches to explain spatial and temporal variabilities of the TOC water quality responses. We systematically quantified the effects of discharge, seasonality, and long-term trend as factors controlling intra-annual (among year) and inter-annual (within year) variabilities of TOC by evaluating the spatial variability in model coefficients and catchment characteristics (e.g. land cover, retention time, soil type). Catchment area (0.18-47,000 km(2)) and land cover types (forests, agriculture and alpine terrain) are typical for the boreal and hemiboreal zones across Fennoscandia. Watercourses had at least 6 years of monthly water quality observations between 1990 and 2010. Statistically significant models (p < 0.05) describing variation of TOC in streamflow were identified in 209 of 215 watercourses with a mean Nash-Sutcliffe efficiency index of 0.44. Increasing long-term trends were observed in 149 (70%) of the watercourses, and intra-annual variation in TOC far exceeded inter-annual variation. The average influences of the discharge and seasonality terms on intra-annual variations in daily TOC concentration were 1.4 and 1.3 mg l(-1) (13 and 12% of the mean annual TOC), respectively. The average increase in TOC was 0.17 mg l(-1) year(-1) (1.6% year(-1)). Multivariate regression with over 90 different catchment characteristics explained 21% of the spatial variation in the linear trend coefficient, less than 20% of the variation in the discharge coefficient and 73% of the spatial variation in mean TOC. Specific discharge, water residence time, the variance of daily precipitation, and lake area, explained 45% of the spatial variation in the amplitude of the TOC seasonality. Because the main drivers of temporal variability in TOC are seasonality and discharge, first-order estimates of the influences of climatic variability and change on TOC concentration should be predictable if the studied catchments continue to respond similarly. (C) 2015 Elsevier B.V. All rights reserved.

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