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  • 1. Bishop, K
    et al.
    Buffam, I
    Erlandsson, M
    Fölster, J
    Laudon, H
    Seibert, Jan
    Stockholm University.
    Temnerud, J
    Aqua Incognita: the unknown headwaters2008In: Hydrological Processes, Vol. 22, no 8, p. 1239-1242Article in journal (Refereed)
  • 2. Bishop, K.
    et al.
    Seibert, J.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Nyberg, L.
    Rodhe, A.
    Water storage in a till catchment. II: Implications of transmissivity feedback for flow paths and turnover times2011In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 25, no 25, p. 3950-3959Article in journal (Refereed)
    Abstract [en]

    This paper explores the flow paths and turnover times within a catchment characterized by the transmissivity feedback mechanism where there is a strong increase in the saturated hydraulic conductivity towards the soil surface and precipitation inputs saturate progressively more superficial layers of the soil profile. The analysis is facilitated by the correlation between catchment water storage and groundwater levels, which made it possible to model the daily spatial distribution of water storage, both vertically in different soil horizons and horizontally across a 6300-m2 till catchment. Soil properties and episodic precipitation input dynamics, combined with the influence of topographic features, concentrate flow in the horizontal, vertical, and temporal dimensions. Within the soil profile, there was a vertical concentration of lateral flow to superficial soil horizons (upper 30?cm of the soil), where much of the annual flow occurred during runoff episodes. Overland flow from a limited portion of the catchment can contribute to peak flows but is not a necessary condition for runoff episodes. The spatial concentration of flow, and the episodic nature of runoff events, resulted in a strong and spatially structured differentiation of local flow velocities within the catchment. There were large differences in the time spent by the laterally flowing water at different depths, with turnover times of lateral flow across a 1-m-wide soil pedon ranging from under 1?h at 10- to 20-cm depth to a month at 70- to 80-cm depth. In many regards, the hydrology of this catchment appears typical of the hydrology in till soils, which are widespread in Fenno-Scandia. Copyright (c) 2011 John Wiley & Sons, Ltd.

  • 3. Breuer, L.
    et al.
    Huisman, J. A.
    Willems, P.
    Bormann, H.
    Bronstert, A.
    Croke, B. F. W.
    Frede, H. G.
    Graff, T.
    Hubrechts, L.
    Jakeman, A. J.
    Kite, G.
    Lanini, J.
    Leavesley, G.
    Lettenmaier, D. P.
    Lindstrom, G.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Sivapalan, M.
    Viney, N. R.
    Assessing the impact of land use change on hydrology by ensemble modeling (LUCHEM). I: Model intercomparison with current land use2009In: Advances in Water Resources, ISSN 0309-1708, E-ISSN 1872-9657, Vol. 32, no 2, p. 129-146Article in journal (Refereed)
    Abstract [en]

    This paper introduces the project on 'Assessing the impact of land use change on hydrology by ensemble modeling (LUCHEM)' that aims at investigating the envelope of predictions on changes in hydrological fluxes due to land use change. As part of a series of four papers, this paper outlines the motivation and setup of LUCHEM, and presents a model intercomparison for the present-day simulation results. Such an intercomparison provides a valuable basis to investigate the effects of different model structures on model predictions and paves the ground for the analysis of the performance of multi-model ensembles and the reliability of the scenario predictions in companion papers. in this study, we applied a set of 10 lumped, semi-lumped and fully distributed hydrological models that have been previously used in land use change studies to the low mountainous Dill catchment. Germany. Substantial differences in model performance were observed with Nash-Sutcliffe efficiencies ranging from 0.53 to 0.92. Differences in model performance were attributed to (1) model input data, (2) model calibration and (3) the physical basis of the models. The models were applied with two sets of input data: an original and a homogenized data set. This homogenization of precipitation, temperature and leaf area index was performed to reduce the variation between the models. Homogenization improved the comparability of model simulations and resulted in a reduced average bias, although some variation in model data input remained. The effect of the physical differences between models on the long-term water balance was mainly attributed to differences in how models represent evapotranspiration. Semi-lumped and lumped conceptual models slightly outperformed the fully distributed and physically based models. This was attributed to the automatic model calibration typically used for this type of models. Overall, however, we conclude that there was no superior model if several measures of model performance are considered and that all models are suitable to participate in further multi-model ensemble set-ups and land use change scenario investigations.

  • 4. Buffam, Ishi
    et al.
    Laudon, Hjalmar
    Seibert, Jan
    Stockholm University.
    Mörth, Carl Magnus
    Stockholm University.
    Bishop, Kevin
    Spatial heterogeneity of the spring flood acid pulse in a boreal stream network2008In: Science of the Total Environment, Vol. 407, no 1, p. 708-722Article in journal (Refereed)
  • 5. Carey, Sean K.
    et al.
    Tetzlaff, Doerthe
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Soulsby, Chris
    Buttle, Jim
    Laudon, Hjalmar
    McDonnell, Jeff
    McGuire, Kevin
    Caissie, Daniel
    Shanley, Jamie
    Kennedy, Mike
    Devito, Kevin
    Pomeroy, John W.
    Inter-comparison of hydro-climatic regimes across northern catchments: synchronicity, resistance and resilience2010In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 24, no 24, p. 3591-3602Article in journal (Refereed)
    Abstract [en]

    The higher mid-latitudes of the Northern Hemisphere are particularly sensitive to climate change as small differences in temperature determine frozen ground status, precipitation phase, and the magnitude and timing of snow accumulation and melt. An international inter-catchment comparison program, North-Watch, seeks to improve our understanding of the sensitivity of northern catchments to climate change by examining their hydrological and biogeochemical responses. The catchments are located in Sweden (Krycklan), Scotland (Mharcaidh, Girnock and Strontian), the United States (Sleepers River, Hubbard Brook and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). This briefing presents the initial stage of the North-Watch program, which focuses on how these catchments collect, store and release water and identify 'types' of hydro-climatic catchment response. At most sites, a 10-year data of daily precipitation, discharge and temperature were compiled and evaporation and storage were calculated. Inter-annual and seasonal patterns of hydrological processes were assessed via normalized fluxes and standard flow metrics. At the annual-scale, relations between temperature, precipitation and discharge were compared, highlighting the role of seasonality, wetness and snow/frozen ground. The seasonal pattern and synchronicity of fluxes at the monthly scale provided insight into system memory and the role of storage. We identified types of catchments that rapidly translate precipitation into runoff and others that more readily store water for delayed release. Synchronicity and variance of rainfall-runoff patterns were characterized by the coefficient of variation (cv) of monthly fluxes and correlation coefficients. Principal component analysis (PCA) revealed clustering among like catchments in terms of functioning, largely controlled by two components that (i) reflect temperature and precipitation gradients and the correlation of monthly precipitation and discharge and (ii) the seasonality of precipitation and storage. By advancing the ecological concepts of resistance and resilience for catchment functioning, results provided a conceptual framework for understanding susceptibility to hydrological change across northern catchments.

  • 6. Cory, Neil
    et al.
    Laudon, Hjalmar
    Köhler, Stephan
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Bishop, Kevin
    Evolution of soil solution aluminum during transport along a forested boreal hillslope2007In: J. Geophys. Res., Vol. 112, p. G03014-Article in journal (Refereed)
  • 7. Dahlke, H. E.
    et al.
    Behrens, T.
    Seibert, J.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Andersson, L.
    Test of statistical means for the extrapolation of soil depth point information using overlays of spatial environmental data and bootstrapping techniques2009In: Hydrological Processes, Vol. 23, no 21, p. 3017-3029Article in journal (Refereed)
    Abstract [en]

    Hydrological modelling depends highly on the accuracy and uncertainty of model input parameters such as soil properties. Since most of these data are field Surveyed, geostatistical techniques Such as kriging, classification and regression trees or more sophisticated soil-landscape models need to be applied to interpolate point information to the area. Most of the existing interpolation techniques require a random or regular distribution of points Within the study area but are not adequate to satisfactorily interpolate soil catena or transect data. The soil landscape model presented in this study is predicting soil information from transect or catena point data using a statistical mean (arithmetic, geometric and harmonic mean) to calculate the soil information based on class means of merged spatial explanatory variables. A data set of 226 soil depth measurements covering a range of 0-6.5 m was used to test the model. The point data were sampled along four transects in the Stubbetorp catchment, SE-Sweden. We overlaid a geomorphology map (8 classes) with digital elevation model-derived topographic index maps (2-9 classes) to estimate the range of error the model produces with changing sample size and input maps. The accuracy of the soil depth predictions was estimated with the root mean square error (RMSE) based oil a testing and training data set. RMSE ranged generally between 0.73 and 0.83 m +/- 0.013 m depending on the amount of classes the merged layers had, but were smallest for a map combination with a low number of classes predicted with the harmonic mean (RMSE = 0.46 m). The results show that the prediction accuracy of this method depends oil the number of point values in the sample, the value range of the measured attribute and the initial correlations between point values and explanatory variables, but suggests that the model approach is in general scale invariant. Copyright (C) 2009 John Wiley & Sons, Ltd.

  • 8. Dunn, S. M.
    et al.
    Freer, J.
    Weiler, M.
    Kirkby, M. J.
    Seibert, J.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Quinn, P. F.
    Lischeid, G.
    Tetzlaff, D.
    Soulsby, C.
    Conceptualization in catchment modelling: simply learning?2008In: Hydrological Processes, Vol. 22, no 13, p. 2389-2393Article in journal (Refereed)
  • 9. Ewen, Tracy
    et al.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. University of Zurich, Germany; Uppsala University, Sweden.
    Learning about water resource sharing through game play2016In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 20, no 10, p. 4079-4091Article in journal (Refereed)
    Abstract [en]

    Games are an optimal way to teach about water resource sharing, as they allow real-world scenarios to be enacted. Both students and professionals learning about water resource management can benefit from playing games, through the process of understanding both the complexity of sharing of resources between different groups and decision outcomes. Here we address how games can be used to teach about water resource sharing, through both playing and developing water games. An evaluation of using the web-based game Irrigania in the classroom setting, supported by feedback from several educators who have used Irrigania to teach about the sustainable use of water resources, and decision making, at university and high school levels, finds Irrigania to be an effective and easy tool to incorporate into a curriculum. The development of two water games in a course for masters students in geography is also presented as a way to teach and communicate about water resource sharing. Through game development, students learned soft skills, including critical thinking, problem solving, team work, and time management, and overall the process was found to be an effective way to learn about water resource decision outcomes. This paper concludes with a discussion of learning outcomes from both playing and developing water games.

  • 10. Exbrayat, J. F.
    et al.
    Viney, N. R.
    Seibert, J.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Frede, H. G.
    Breuer, L.
    Multi-model data fusion as a tool for PUB: example in a Swedish mesoscale catchment2011In: Adv. Geosci., Vol. 29, p. 43-50Article in journal (Refereed)
  • 11. Exbrayat, J. -F
    et al.
    Viney, N. R.
    Seibert, J.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Wrede, S.
    Frede, H. -G
    Breuer, L.
    Ensemble modelling of nitrogen fluxes: data fusion for a Swedish meso-scale catchment2010In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 14, no 12, p. 2383-2397Article in journal (Refereed)
  • 12. Geris, J.
    et al.
    Tetzlaff, D.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. University of Zurich, Switzerland.
    Vis, M.
    Soulsby, C.
    CONCEPTUAL MODELLING TO ASSESS HYDROLOGICAL IMPACTS AND EVALUATE ENVIRONMENTAL FLOW SCENARIOS IN MONTANE RIVER SYSTEMS REGULATED FOR HYDROPOWER2015In: Rivers Research and Applications: an international journal devoted to river research and management, ISSN 1535-1459, E-ISSN 1535-1467, Vol. 31, no 9, p. 1066-1081Article in journal (Refereed)
    Abstract [en]

    To improve understanding of natural and managed flow regimes in data-sparse regulated river systems in montane areas, the commonly used Hydrologiska Byrans Vattenbalansavdelning (HBV) conceptual run-off model was adapted to incorporate water regulation components. The extended model was then applied to the heavily regulated river Lyon (391 km(2)) in Scotland to reconstruct the natural flow regime and to assess the impacts of regulation at increasing spatial scales. Multi-criteria model evaluation demonstrated that the model performed well in capturing the dominant catchment processes and regulation effects, especially at the timescales at which operation rules apply. The main change as a result of regulation in the river Lyon is a decrease in inter-annual and intra-annual variability of all elements of the flow regime, in terms of magnitude, frequency, and duration. Although these impacts are most pronounced directly downstream of the impoundments, the regulation effects propagate throughout the river system. The modelling approach is flexible and widely applicable and only limited amounts of data are required. Moreover, results are easily communicated to stakeholders. It has the potential to contribute to the development of flow regimes that may be more beneficial to the ecological status of rivers. In the case of the river Lyon, it is likely that this involves a more variable release regime. The approach developed here provides a tool for assessing impacts on flow regimes and informing environmental flows in other data-sparse regions with heavily regulated montane river systems.

  • 13.
    Grabs, T.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Bishop, K.
    Laudon, H.
    Lyon, Steve W.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Riparian zone hydrology and soil water total organic carbon (TOC): implications for spatial variability and upscaling of lateral riparian TOC exports2012In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 9, no 10, p. 3901-3916Article in journal (Refereed)
    Abstract [en]

    Groundwater flowing from hillslopes through riparian (near-stream) soils often undergoes chemical transformations that can substantially influence stream water chemistry. We used landscape analysis to predict total organic carbon (TOC) concentration profiles and groundwater levels measured in the riparian zone (RZ) of a 67 km(2) catchment in Sweden. TOC exported laterally from 13 riparian soil profiles was then estimated based on the riparian flow-concentration integration model (RIM). Much of the observed spatial variability of riparian TOC concentrations in this system could be predicted from groundwater levels and the topographic wetness index (TWI). Organic riparian peat soils in forested areas emerged as hotspots exporting large amounts of TOC. These TOC fluxes were subject to considerable temporal variations caused by a combination of variable flow conditions and changing soil water TOC concentrations. Mineral riparian gley soils, on the other hand, were related to rather small TOC export rates and were characterized by relatively time-invariant TOC concentration profiles. Organic and mineral soils in RZs constitute a heterogeneous landscape mosaic that potentially controls much of the spatial variability of stream water TOC. We developed an empirical regression model based on the TWI to move beyond the plot scale and to predict spatially variable riparian TOC concentration profiles for RZs underlain by glacial till.

  • 14.
    Grabs, Thomas
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Bishop, Kevin
    Department of Aquatic Sciences and Assessment, SLU, Uppsala, Sweden.
    Laudon, Hjalmar
    Department of Forest Ecology and Management, SLU, Umeå, Sweden.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Riparian zone processes and soil water total organic carbon (TOC): Implications for spatial variability, upscaling and carbon exportsManuscript (preprint) (Other academic)
    Abstract [en]

    Considerable amounts of groundwater inflows pass through riparian soils before discharging into stream networks. The interaction of groundwater inflows from adjacent hillslopes with riparian soils often changes the biogeochemical signature of the water. This mechanism often makes (near stream) riparian zones (RZs) key areas in the landscape that substantially influence stream water chemistry. Here we combine landscape analysis with total organic carbon (TOC) concentrations and groundwater levels measured at the riparian observatory in the boreal Krycklan catchment to investigate how terrain has shaped riparian processes and TOC characteristics. A considerable spatial variability of riparian TOC concentrations is presented in this system which can be related to variable groundwater levels and values of the topographic wetness index (TWI). Organic-rich riparian peat soils in forested areas emerged as hotspots exporting large amounts of TOC. These exports are subject to considerable temporal variations caused by variable flow conditions and changing TOC concentrations. Organic-poor riparian soils, on the other hand, exported only small and relatively time-invariant amounts of TOC. Organic-rich and organic-poor soils in RZs combine to a landscape mosaic that regulates much of spatial variability of stream water TOC. We finally present an empirical regression-model based on the TWI to predict spatially variable riparian TOC concentration profiles for areas in the Krycklan catchment that are underlain by glacial till.

  • 15.
    Grabs, Thomas
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Jencso, Kelsey G.
    Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana, USA.
    McGlynn, Brian L.
    Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, Montana, USA.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Calculating terrain indices along streams - a new method for separating stream sides2010In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 46Article in journal (Refereed)
    Abstract [en]

    There is increasing interest in assessing riparian zones and their hydrological and biogeochemical buffering capacity with indices derived from hydrologic landscape analysis of digital elevation data. Upslope contributing area is a common surrogate for lateral water flows and can be used to assess the variability of local water inflows to riparian zones and streams. However, current GIS algorithms do not provide a method for easily separating riparian zone and adjacent upland lateral contributions on each side of the stream. Here we propose a new algorithm to compute side-separated contributions along stream networks. We describe the new algorithm and illustrate the importance of distinguishing between lateral inflows on each side of streams with hillslope – riparian zone – stream hydrologic connectivity results from high frequency water table data collected in the 22km 2  Tenderfoot Creek catchment, Montana.

  • 16.
    Grabs, Thomas
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Laudon, Hjalmar
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Modelling spatial patterns of saturated areas: a comparison of the topographic wetness index and a distributed model2007In: Geophysical Research Abstracts, European Geoscience Union , 2007, p. vol 9-Conference paper (Other academic)
    Abstract [en]

    The spatial distribution of saturated areas within a catchment is a key factor to understanding and predicting hydrological response and stream water quality at the catchment scale. The topographic wetness index (TWI, ln(a/tan(beta))) is a widely used measure for assessing the spatial distribution of wetness conditions and only requires distributed elevation data as input. The predicted pattern is constant in time because the index is a static representation of the landscape. In this study we examined the predictions of saturated areas using this static topographic wetness index and compared the spatial predictions with temporally aggregated simulations of a distributed hydrological model. The model was calibrated against discharge measured at the outlet and at two internal points of a small forested catchment in northern Sweden. After calibration the model was applied to a larger 68 km2 catchment which included the subcatchment used for calibration. The dynamic groundwater level simulations of this model were temporally aggregated into dynamic indices. These indices were compared to the static topographic wetness index (TWI). We used the ability to spatially predict the occurrence of wetlands as a validation of the static and dynamic indices. First results indicate that the dynamic approach is superior to the static TWI.

  • 17. Huisman, J. A.
    et al.
    Breuer, L.
    Bormann, H.
    Bronstert, A.
    Croke, B. F. W.
    Frede, H. G.
    Graff, T.
    Hubrechts, L.
    Jakeman, A. J.
    Kite, G.
    Lanini, J.
    Leavesley, G.
    Lettenmaier, D. P.
    Lindström, G.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Sivapalan, M.
    Viney, N. R.
    Willems, P.
    Assessing the impact of land use change on hydrology by ensemble modeling (LUCHEM) III: Scenario analysis2009In: Advances in Water Resources, ISSN 0309-1708, E-ISSN 1872-9657, Vol. 32, no 2, p. 159-170Article in journal (Refereed)
    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.

  • 18.
    Jonsson, Christina E.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Leng, Melanie J.
    NERC Isotope Geosciences Laboratory , BGS, UK.
    Rosqvist, Gunhild C.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Arrowsmith, Carol
    NERC Isotope Geosciences Laboratory, BGS, UK.
    Stable oxygen and hydrogen isotopes in sub-Arctic lake wateras from northern Sweden2009In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 376, p. 143-151Article in journal (Refereed)
    Abstract [en]

    Lakes in sub-Arctic regions have the potential of retaining many different aspects of water isotope composition in their sediments which can be used for palaeoclimate reconstruction. It is therefore important to understand the modern isotope hydrology of these lakes. Here we discuss the significance of variations in water isotope composition of a series of lakes located in north-west Swedish Lapland. Climate in this region is forced by changes in the North Atlantic which renders it an interesting area for climate reconstructions. We compare δ18Olake and δ2Hlake collected between 2001 and 2006 and show that the lakes in this sub-Arctic region are currently mainly recharged by shallow groundwater and precipitation which undergoes little subsequent evaporation, and that the d18O and δ2H composition of input to the majority of the lakes varies on a seasonal basis between winter precipitation (and spring thaw) and summer precipitation. Seasonal variations in the isotopic composition of the lake waters are larger in lakes with short residence times (<6 months), which react faster to seasonal changes in the precipitation, compared to lakes with longer residence times (>6 months), which retain an isotopic signal closer to that of annual mean precipitation. Lake waters also show a range of isotope values between sites due to catchment elevation and timing of snow melt. The lake water data collected in this study was supported by isotope data from lake waters, streams and ground waters from1995 to 2000 reported in other studies.

  • 19. Juston, J.
    et al.
    Seibert, J.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Johansson, P. O.
    Temporal sampling strategies and uncertainty in calibrating a conceptual hydrological model for a small boreal catchment2009In: Hydrological Processes, Vol. 23, no 21, p. 3093-3109Article in journal (Refereed)
    Abstract [en]

    How much data is needed for calibration of a hydrological catchment model? In this paper we address this question by evaluating the information contained in different subsets of discharge and groundwater time series for multi-objective calibration of a conceptual hydrological model within the framework of an uncertainty analysis. The study site was a 5.6-km(2) catchment within the Forsmark research site in central Sweden along the Baltic coast. Daily time series data were available for discharge and several groundwater wells within the catchment for a continuous 1065-day period. The hydrological model was a site-specific modification of the Conceptual HBV model. The uncertainty analyses were based on a selective Monte Carlo procedure. Thirteen subsets of the complete time series data were investigated with the idea that these represent realistic intermittent sampling strategies. Data Subsets included split-samples and various combinations of weekly, monthly, and quarterly fixed interval subsets, as well as a 53-day 'informed observer' Subset that utilized once per month samples except during March and April-the months containing large and often dominant snow melt events-when sampling was once per week. Several of these subsets, including that of the informed observer, provided very similar constraints on model calibration and parameter identification as the full data record, ill terms of credibility bands on simulated time series, posterior parameter distributions, and performance indices calculated to the full dataset. This result Suggests that hydrological sampling designs can, at least in some cases, be optimized. Copyright (C) 2009 John Wiley & Sons, Ltd.

  • 20. Konz, M.
    et al.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    On the value of glacier mass balances for hydrological model calibration2010In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 385, no 1-4, p. 238-246Article in journal (Refereed)
    Abstract [en]

    Hydrological modelling of glacierized catchments is challenging because internal inconsistencies might be hidden due to ice melt which represents an additional source of water. This is even more significant if there are no data available to evaluate model simulations, as is often the case in remote areas. On the other hand, these glacierized catchments are important source regions for water, and detailed knowledge of water availability is a prerequisite for good resource management strategies. An important question is how useful a limited amount of data might be for model applications. Therefore, in this study the predictive power of limited discharge measurements, mass balance observations and the combination of both was analyzed by means of Monte Carlo analyses with multi-criteria model performance evaluation. Ensembles of 100 parameter sets were selected by evaluating the simulations based on a limited number of discharge measurements, glacier mass balance, and the combination of discharge and mass balance observations. Then the ensemble simulation of runoff was evaluated for the entire runoff series. The result indicated that a single annual glacier mass balance observation contained useful information to constrain hydrological models. Combining mass balance observations with a few discharge data improved the internal consistency and significantly reduced the uncertainties compared to parameter set selections based on discharge measurements alone. To obtain good ensemble predictions, information on discharge was required for at least 3 days during the melting season. This demonstrated that the timing of runoff measurements is important for the information contained in these data.

  • 21. Kruitbos, Laura M.
    et al.
    Tetzlaff, Doerthe
    Soulsby, Chris
    Buttle, Jim
    Carey, Sean K.
    Laudon, Hjalmar
    McDonnell, Jeffrey J.
    McGuire, Kevin
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Cunjak, Richard
    Shanley, Jamie
    Hydroclimatic and hydrochemical controls on Plecoptera diversity and distribution in northern freshwater ecosystems2012In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 693, no 1, p. 39-53Article in journal (Refereed)
    Abstract [en]

    Freshwater ecosystems in the mid- to upper-latitudes of the northern hemisphere are particularly vulnerable to the impact of climate change as slight changes in air temperature can alter the form, timing, and magnitude of precipitation and consequent influence of snowmelt on streamflow dynamics. Here, we examine the effects of hydro-climate, flow regime, and hydrochemistry on Plecoptera (stonefly) alpha (alpha) diversity and distribution in northern freshwater ecosystems. We characterized the hydroclimatic regime of seven catchments spanning a climatic gradient across the northern temperate region and compared them with estimates of Plecoptera genera richness. By a space-for-time substitution, we assessed how warmer temperatures and altered flow regimes may influence Plecoptera alpha diversity and composition at the genus level. Our results show wide hydroclimatic variability among sites, including differences in temporal streamflow dynamics and temperature response. Principal component analysis showed that Plecoptera genera richness was positively correlated with catchment relief (m), mean and median annual air temperature (A degrees C), and streamflow. These results provide a preliminary insight into how hydroclimatic change, particularly in terms of increased air temperature and altered streamflow regimes, may create future conditions more favorable to some Plecopteras in northern catchments.

  • 22. Köhler, S. J.
    et al.
    Buffam, I.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Bishop, K. H.
    Laudon, H.
    Dynamics of stream water TOC concentrations in a boreal headwater catchment: Controlling factors and implications for climate scenarios2009In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 373, no 1-2, p. 44-56Article in journal (Refereed)
    Abstract [en]

    Two different but complementary modelling approaches for reproducing the observed dynamics of total organic carbon (TOC) in a boreal stream are presented. One is based on a regression analysis, while the other is based on riparian soil conditions using a convolution of flow and concentration. Both approaches are relatively simple to establish and help to identify gaps in the process understanding of the TOC transport from soils to catchments runoff. The largest part of the temporal variation of stream TOC concentrations (4-46 mg L-1) in a forested headwater stream in the boreal zone in northern Sweden may be described using a four-parameter regression equation that has runoff and transformed air temperature as sole input variables. Runoff is assumed to be a proxy for soil wetness conditions and changing flow pathways which in turn caused most of the stream TOC variation. Temperature explained a significant part of the observed inter-annual variability. Long-term riparian hydrochemistry in soil solutions within 4 m of the stream also captures a surprisingly large part of the observed variation of stream TOC and highlights the importance of riparian soils. The riparian zone was used to reproduce stream TOC with the help of a convolution model based on flow and average riparian chemistry as input variables. There is a significant effect of wetting of the riparian soil that translates into a memory effect for subsequent episodes and thus contributes to controlling stream TOC concentrations. Situations with high flow introduce a large amount of variability into stream water TOC that may be related to memory effects, rapid groundwater fluctuations and other processes not identified so far. Two different climate scenarios for the region based on the IPCC scenarios were applied to the regression equation to test what effect the expected increase in precipitation and temperature and resulting changes in runoff would have on stream TOC concentrations assuming that the soil conditions remain unchanged. Both scenarios resulted in a mean increase of stream TOC concentrations of between 1.5 and 2.5 mg L-1 during the snow free season, which amounts to approximately 15% more TOC export compared to present conditions. Wetter and warmer conditions in the late autumn led to a difference of monthly average TOC of up to 5 mg L-1, suggesting that stream TOC may be particularly susceptible to climate variability during this season.

  • 23. Laudon, Hjalmar
    et al.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Grabs, Thomas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Buffam, Ishi
    Bishop, Kevin
    Mörth, Carl-Magnus
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    The Krycklan Catchment Study, Sweden: A field based experimental platform for linking small-scale process understanding to landscape patterns2007Conference paper (Other academic)
    Abstract [en]

    The Krycklan Catchment Study (KCS) (http://ccrew.sek.slu.se/krycklan), is a multiscale experimental catchment located in the boreal region of northern Sweden. The catchment is extensively instrumented for hydrological and biogeochemical research, including 15 permanent gauging stations, ranging from 3 ha to 6700 ha in size, intensively sampled and continuously monitored to quantify temporal and spatial variations in water chemistry and discharge. An additional 90 locations are sampled occasionally for water chemistry at different runoff stages. The multi-investigator KCS has been developed to provide a direct insight into the governing hydrological and biogeochemical processes at a range of catchment scales and consists at present of over 30 separate projects. Its location within an established Experimental Forest provides a comprehensive instrumental infrastructure, long-term climate monitoring facilities and a small research catchment where process-based hillslope, hydrological and biogeochemical research has been conducted for three decades. Recently two new major investments are being implemented. The first includes a Riparian Observatory with over 200 soil lysimeters in the riparian zone. The second investment is the use of laserscanning (LIDAR) which makes KCS one of the first large-scale research catchments where high-resolution elevation and ground cover data are available for hydrological and water quality modeling.

  • 24. Laudon, Hjalmar
    et al.
    Sjöblom, Viktor
    Buffam, Ishi
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Mörth, Magnus
    Department of Geology and Geochemistry.
    The role of catchment scale and landscape characteristics for runoff generation of boreal streams2007In: Journal of Hydrology, Vol. 344, no 3-4, p. 198-209Article in journal (Refereed)
  • 25. Lindgren, Georg
    et al.
    Wrede, Sebastian
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Wallin, Mats
    Nitrogen source apportionment modeling and the effect of land-use class related runoff contributions2007In: Nordic Hydrology, Vol. 38, no 4-5, p. 317–331-Article in journal (Refereed)
    Abstract [en]

    Models simulating nutrient transport at the catchment scale are frequently used for source

    apportionment and thereby for finding cost-efficient management strategies for water quality improvements. One

    typical modelling approach at the catchment scale is the use of leaching coefficients (mass per unit flow of

    water) to compute the nutrient input based on land-use information. In this study two different such model

    approaches, the lumped Fyrismodel and the distributed HBV-N-D model, were compared based on simulations

    for the River Fyris catchment in central Sweden. A major difference between the models were different

    assumptions of specific runoff variations between different land-use classes. These differences had a

    considerable effect on the computed source apportionment. The higher specific runoff from agricultural areas in

    the HBV-N-D model compared to the Fyrismodel resulted in a larger contribution of agricultural areas to the total

    nitrogen export. These results demonstrate the importance of the assumptions of the spatial variation of specific

    runoff on source apportionment HBV-N-D model estimations.

  • 26. Lindsay, John B.
    et al.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. University of Zurich .
    Measuring the significance of a divide to local drainage patterns2013In: International Journal of Geographical Information Science, ISSN 1365-8816, E-ISSN 1365-8824, Vol. 27, no 7, p. 1453-1468Article in journal (Refereed)
    Abstract [en]

    This article presents a framework for estimating a new topographic attribute derived from digital elevation models (DEMs) called maximum branch length (B-max). Branch length is defined as the distance travelled along a flow path initiated at one grid cell to the confluence with the flow path passing through a second cell. B-max is the longest branch length measured for a grid cell and its eight neighbours. The index provides a physically meaningful method for assessing the relative significance of drainage divides to the dispersion of materials and energy across a landscape, that is, it is a measure of divide size'. B-max is particularly useful for studying divide network structure, for mapping drainage divides, and in landform classification applications. Sensitivity analyses were performed to evaluate the robustness of estimates of B-max to the algorithm used to estimate flow lengths and the prevalence of edge effects resulting from inadequate DEM extent. The findings suggest that the index is insensitive to the specific flow algorithm used but that edge effects can result in significant underestimation along major divides. Edge contamination can, however, be avoided by using an appropriately extensive DEM.

  • 27.
    Lyon, S. W.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Laudon, H.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Morth, M.
    Tetzlaff, D.
    Bishop, K. H.
    Controls on snowmelt water mean transit times in northern boreal catchments2010In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 24, no 12, p. 1672-1684Article in journal (Refereed)
    Abstract [en]

    Catchment-scale transit times for water are increasingly being recognized as an important control on geochemical processes. In this study, snowmelt water mean transit times (MTTs) were estimated for the 15 Krycklan research catchments in northern boreal Sweden. The snowmelt water MTTs were assumed to be representative of the catchment-scale hydrologic response during the spring thaw period and, as such, may be considered to be a component of the catchment's overall MTT. These snowmelt water MTTs were empirically related to catchment characteristics and landscape structure represented by using different indices of soil cover, topography and catchment similarity. Mire wetlands were shown to be significantly correlated to snowmelt MTTs for the studied catchments. In these wetlands, shallow ice layers form that have been shown to serve as impervious boundaries to vertical infiltration during snowmelt periods and, thus, alter the flow pathways of water in the landscape. Using a simple thought experiment, we could estimate the potential effect of thawing of ice layers on snowmelt hydrologic response using the empirical relationship between landscape structure (represented using a catchment-scale Pe number) and hydrologic response. The result of this thought experiment was that there could be a potential increase of 20-45% in catchment snowmelt water MTTs for the Krycklan experimental catchments. It is therefore possible that climatic changes present competing influences on the hydrologic response of northern boreal catchments that need to be considered. For example, MTTs may tend to decrease during some times of the year due to an acceleration in the hydrologic cycle, while they tend to increase MTTs during other times of the year due to shifts in hydrologic flow pathways. The balance between the competing influences on a catchment's MTT has consequences on climatic feedbacks as it could influence hydrological and biogeochemical cycles at the catchment scale for northern latitude boreal catchments. Copyright (C) 2010 John Wiley & Sons, Ltd.

  • 28.
    Lyon, Steve
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Grabs, Thomas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Laudon, Hjalmar
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Bishop, Kevin
    Variability of groundwater levels and total organic carbon (TOC) in the riparian zone of a boreal2011In: Journal of Geophysical Research - Biogeosciences, Vol. 116, no G01020Article in journal (Refereed)
    Abstract [en]

    The riparian zone is a narrow corridor where hillslopes (and their associated hydrobiogeochemical processes) interface with the river system. As such, the riparian zone serves as the last piece of landscape with which water interacts as it transitions from being water flowing primarily through the landscape (i.e., shallow groundwater) to water flowing primarily on the landscape (i.e., stream water). This study investigates the spatiotemporal variability in riparian-zone soil water total organic carbon (TOC) and its relation to the shallow groundwater table using observations from the recently instrumented riparian observatory in the Krycklan catchment study area located in boreal northern Sweden. In general, there is a decrease in TOC concentration with depth down through the soil profile. The rate of this decrease was variable among the six monthly samplings used in this study. The spatial variability of soil water TOC in the riparian zone was connected to the spatial variability of the shallow groundwater levels. This demonstrated the importance of the temporal variation of flow pathways and the mixing of waters from different sources of TOC moving into and through the riparian zone. The coupled variation of the hydrologic and biogeochemical systems raised questions about the ability of simple lumped approaches to accurately predict how in-stream TOC concentrations will change with climate and/or land use. The integrated sampling approach in the riparian observatory covers both hydrologic and biogeochemical aspects of soil water TOC and provides a basis for development and testing of distributed, physically based transport models.

  • 29.
    Lyon, Steve
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Seibert, Jan
    Lembo, Arthur
    Steenhuis, Tammo
    Walter, Todd
    Incorporating landscape characteristics in a distance metric for interpolating between observations of stream water chemistry2008In: Hydrology and Earth System Sciences, Vol. 12, p. 1229-1239Article in journal (Refereed)
    Abstract [en]

    Spatial patterns of water chemistry along stream networks can be quantified using synoptic or ‘snapshot’ sampling. The basic idea is to sample stream water at many points over a relatively short period of time. Even for intense sampling campaigns, the number of sample points is limited and interpolation methods, like kriging, are commonly used to produce continuous maps of water chemistry based on the point observations from the synoptic sampling. Interpolated concentrations are influenced heavily by how distance between points along the stream network is defined. In this study, we investigate different ways to define distance and test these based on data from a snapshot sampling campaign in a 37-km2 watershed in the Catskill Mountains region (New York State). Three distance definitions (or metrics) were compared: Euclidean or straight-line distance, in-stream distance, and in-stream distance adjusted according characteristics of the local contributing area, i.e., an adjusted in-stream distance. Using the adjusted distance metric resulted in a lower cross-validation error of the interpolated concentrations, i.e., a better agreement of kriging results with measurements, than the other distance definitions. The adjusted distance metric can also be used in an exploratory manner to test which landscape characteristics are most influential for the spatial patterns of stream water chemistry and, thus, to target future investigations to gain process-based understanding of in-stream chemistry dynamics.

  • 30.
    Lyon, Steve
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Sorensen, R
    Stendahl, J
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Using landscaep charactersitics to define an adjusted distance metric for improving kriging interpolations2010In: International Journal of Geographical Information Science, ISSN 1365-8816, E-ISSN 1365-8824, Vol. 24, no 5, p. 723-740Article in journal (Refereed)
    Abstract [en]

    Interpolation of point measurements using geostatistical techniques such as kriging can be used to estimate values at non-sampled locations in space. Traditional geostatistics are based on the spatial autocorrelation concept that nearby things are more related than distant things. In this study, additional information was used to modify the traditional Euclidean concept of distance into an adjusted distance metric that incorporates similarity in terms of quantifiable landscape characteristics such as topography or land use. This new approach was tested by interpolating soil moisture content, pH and carbon-tonitrogen (C:N) ratio measured in both the mineral and the organic soil layers at a field site in central Sweden. Semivariograms were created using both the traditional distance metrics and the proposed adjusted distance metrics to carry out ordinary kriging (OK) interpolations between sampling points. In addition, kriging with external drift (KED) was used to interpolate soil properties to evaluate the ability of the adjusted distance metric to incorporate secondary data into interpolations. The new adjusted distance metric typically lowered the nugget associated with the semivariogram, thereby better representing small-scale variability in the measured data compared to semivariograms based on the traditional distance metric. The pattern of the resulting kriging interpolations using KED and OK based on the adjusted distance metric were similar because they represented secondary data and, thus, enhanced small-scale variability compared to traditional distance OK. This created interpolations that agreed better with what is expected for the real-world spatial variation of the measured properties. Based on cross-validation error, OK interpolations using the adjusted distance metric better fit observed data than either OK interpolations using traditional distance or KED.

  • 31.
    Lyon, Steve W.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Nathanson, Marcus
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Spans, Andre
    Grabs, Thomas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Laudon, Hjalmar
    Temnerud, Johan
    Bishop, Kevin H.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Specific discharge variability in a boreal landscape2012In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 48, p. W08506-Article in journal (Refereed)
    Abstract [en]

    Specific discharge variations within a mesoscale catchment were studied on the basis of three synoptic sampling campaigns. These were conducted during stable flow conditions within the Krycklan catchment study area in northern Sweden. During each campaign, about 80 individual locations were measured for discharge draining from catchment areas ranging between 0.12 and 67 km(2). These discharge samplings allowed for the comparison between years within a given season (September 2005 versus September 2008) and between seasons within a given year (May 2008 versus September 2008) of specific discharge across this boreal landscape. There was considerable variability in specific discharge across this landscape. The ratio of the interquartile range (IQR) defined as the difference between the 75th and 25th percentiles of the specific discharges to the median of the specific discharges ranged from 37% to 43%. Factor analysis was used to explore potential relations between landscape characteristics and the specific discharge observed for 55 of the individual locations that were measured in all three synoptic sampling campaigns. Percentage wet area (i.e., wetlands, mires, and lakes) and elevation were found to be directly related to the specific discharge during the drier September 2008 sampling while potential annual evaporation was found to be inversely related. There was less of a relationship determined during the wetter post spring flood May 2008 sampling and the late summer rewetted September 2005 sampling. These results indicate the ability of forests to dry out parts of the catchment over the summer months while wetlands keep wet other parts. To demonstrate the biogeochemical implications of such spatiotemporal variations in specific discharge, we estimate dissolved organic carbon (DOC) exports with available data for the May 2008 and September 2008 samplings using both the spatially variable observed specific discharges and the spatially constant catchment average values. The average absolute difference in DOC export for the various subcatchments between using a variable and using a constant specific discharge was 28% for the May 2008 sampling and 20% for the September 2008 sampling.

  • 32. McDonnell, J. J.
    et al.
    McGuire, K.
    Aggarwal, P.
    Beven, K. J.
    Biondi, D.
    Destouni, G.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Dunn, S.
    James, A.
    Kirchner, J.
    Kraft, P.
    Lyon, S.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Maloszewski, P.
    Newman, B.
    Pfister, L.
    Rinaldo, A.
    Rodhe, A.
    Sayama, T.
    Seibert, J.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Solomon, K.
    Soulsby, C.
    Stewart, M.
    Tetzlaff, D.
    Tobin, C.
    Troch, P.
    Weiler, M.
    Western, A.
    Worman, A.
    Wrede, S.
    How old is streamwater? Open questions in catchment transit time conceptualization, modelling and analysis2010In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 24, no 12, p. 1745-1754Article in journal (Refereed)
  • 33.
    Nathanson, Marcus
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Kean, Jason
    Grabs, Thomas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. Uppsala University, Sweden.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. Uppsala University, Sweden; University of Zurich, Switzerland.
    Laudon, Hjalmar
    Lyon, Steve
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Modelling rating curves using remotely sensed LiDAR data2012In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 26, no 9, p. 1427-1434Article in journal (Refereed)
    Abstract [en]

    Accurate stream discharge measurements are important for many hydrological studies. In remote locations, however, it is often difficult to obtain stream flow information because of the difficulty in making the discharge measurements necessary to define stage-discharge relationships (rating curves). This study investigates the feasibility of defining rating curves by using a fluid mechanics-based model constrained with topographic data from an airborne LiDAR scanning. The study was carried out for an 8m-wide channel in the boreal landscape of northern Sweden. LiDAR data were used to define channel geometry above a low flow water surface along the 90-m surveyed reach. The channel topography below the water surface was estimated using the simple assumption of a flat streambed. The roughness for the modelled reach was back calculated from a single measurment of discharge. The topographic and roughness information was then used to model a rating curve. To isolate the potential influence of the flat bed assumption, a ‘hybrid model’ rating curve was developed on the basis of data combined from the LiDAR scan and a detailed ground survey. Whereas this hybrid model rating curve was in agreement with the direct measurements of discharge, the LiDAR model rating curve was equally in agreement with the medium and high flow measurements based on confidence intervals calculated from the direct measurements. The discrepancy between the LiDAR model rating curve and the low flow measurements was likely due to reduced roughness associated with unresolved submerged bed topography. Scanning during periods of low flow can help minimize this deficiency. These results suggest that combined ground surveys and LiDAR scans or multifrequency LiDAR scans that see ‘below’ the water surface (bathymetric LiDAR) could be useful in generating data needed to run such a fluid mechanics-based model. This opens a realm of possibility to remotely sense and monitor stream flows in channels in remote locations.

  • 34. Pool, Sandra
    et al.
    Vis, Marc J. P.
    Knight, Rodney R.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography. Uppsala University, Sweden; University of Zurich, Switzerland.
    Streamflow characteristics from modeled runoff time series importance of calibration criteria selection2017In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 21, no 11, p. 5443-5457Article in journal (Refereed)
    Abstract [en]

    Ecologically relevant streamflow characteristics (SFCs) of ungauged catchments are often estimated from simulated runoff of hydrologic models that were originally calibrated on gauged catchments. However, SFC estimates of the gauged donor catchments and subsequently the ungauged catchments can be substantially uncertain when models are calibrated using traditional approaches based on optimization of statistical performance metrics (e.g., Nash-Sutcliffe model efficiency). An improved calibration strategy for gauged catchments is therefore crucial to help reduce the uncertainties of estimated SFCs for ungauged catchments. The aim of this study was to improve SFC estimates from modeled runoff time series in gauged catchments by explicitly including one or several SFCs in the calibration process. Different types of objective functions were defined consisting of the Nash-Sutcliffe model efficiency, single SFCs, or combinations thereof. We calibrated a bucket-type runoff model (HBV-Hydrologiska Byrans Vattenavdelning-model) for 25 catchments in the Tennessee River basin and evaluated the proposed calibration approach on 13 ecologically relevant SFCs representing major flow regime components and different flow conditions. While the model generally tended to underestimate the tested SFCs related to mean and high-flow conditions, SFCs related to low flow were generally overestimated. The highest estimation accuracies were achieved by a SFC-specific model calibration. Estimates of SFCs not included in the calibration process were of similar quality when comparing a multi-SFC calibration approach to a traditional model efficiency calibration. For practical applications, this implies that SFCs should preferably be estimated from targeted runoff model calibration, and modeled estimates need to be carefully interpreted.

  • 35. Reynolds, J. E.
    et al.
    Halldin, S.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography. Uppsala University, Sweden; University of Zurich, Switzerland.
    Xu, C. Y.
    Definitions of climatological and discharge days: do they matter in hydrological modelling?2018In: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 63, no 5, p. 836-844Article in journal (Refereed)
    Abstract [en]

    The performance of hydrological models is affected by uncertainty related to observed climatological and discharge data. Although the latter has been widely investigated, the effects on hydrological models from different starting times of the day have received little interest. In this study, observational data from one tropical basin were used to investigate the effects on a typical bucket-type hydrological model, the HBV, when the definitions of the climatological and discharge days are changed. An optimization procedure based on a genetic algorithm was used to assess the effects on model performance. Nash-Sutcliffe efficiencies varied considerably between day definitions, with the largest dependence on the climatological-day definition. The variation was likely caused by how storm water was assigned to one or two daily rainfall values depending on the definition of the climatological day. Hydrological models are unlikely to predict high flows accurately if rainfall intensities are reduced because of the day definition.

  • 36. Reynolds, J. E.
    et al.
    Halldin, S.
    Xu, C. Y.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography. Uppsala University, Sweden; University of Zurich, Switzerland.
    Kauffeldt, A.
    Sub-daily runoff predictions using parameters calibrated on the basis of data with a daily temporal resolution2017In: Journal of Hydrology, ISSN 0022-1694, E-ISSN 1879-2707, Vol. 550, p. 399-411Article in journal (Refereed)
    Abstract [en]

    Concentration times in small and medium-sized basins (similar to 10-1000 km(2)) are commonly less than 24 h. Flood-forecasting models are thus required to provide simulations at high temporal resolutions (1 h-6 h), although time-series of input and runoff data with sufficient lengths are often only available at the daily temporal resolution, especially in developing countries. This has led to study the relationships of estimated parameter values at the temporal resolutions where they are needed from the temporal resolutions where they are available. This study presents a methodology to treat empirically model parameter dependencies on the temporal resolution of data in two small basins using a bucket-type hydrological model, HBV-light, and the generalised likelihood uncertainty estimation approach for selecting its parameters. To avoid artefacts due to the numerical resolution or numerical method of the differential equations within the model, the model was consistently run using modelling time steps of one-hour regardless of the temporal resolution of the rainfall-runoff data. The distribution of the parameters calibrated at several temporal resolutions in the two basins did not show model parameter dependencies on the temporal resolution of data and the direct transferability of calibrated parameter sets (e.g., daily) for runoff simulations at other temporal resolutions for which they were not calibrated (e.g., 3 h or 6 h) resulted in a moderate (if any) decrease in model performance, in terms of Nash-Sutcliffe and volume-error efficiencies. The results of this study indicate that if sub-daily forcing data can be secured, flood forecasting in basins with sub-daily concentration times may be possible with model-parameter values calibrated from long time series of daily data. Further studies using more models and basins are required to test the generality of these results.

  • 37. Rinderer, M.
    et al.
    van Meerveld, H. J.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. University of Zurich, Switzerland; Uppsala University, Sweden.
    Topographic controls on shallow groundwater levels in a steep, prealpine catchment: When are the TWI assumptions valid?2014In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 50, no 7, p. 6067-6080Article in journal (Refereed)
    Abstract [en]

    Topographic indices like the Topographic Wetness Index (TWI) have been used to predict spatial patterns of average groundwater levels and to model the dynamics of the saturated zone during events (e. g., TOPMODEL). However, the assumptions underlying the use of the TWI in hydrological models, of which the most important is that groundwater level variation can be approximated by a series of steady state situations, are rarely tested. It is also not clear how well findings from existing hillslope studies on sites with transmissive soil can be transferred to entire catchments with less permeable soils. This study, therefore, evaluated the suitability of selected topographic indices to describe spatial groundwater level variations based on time series from 51 groundwater wells in a 20 ha catchment with low-permeability soils in Switzerland. Results showed that median groundwater levels were correlated to slope, curvature, and TWI, but the strength of correlation depended on whether the indices characterized the local topography or the topography of the upslope contributing area. The correlation between TWI and groundwater levels was not constant over time but decreased at the beginning of rainfall events, indicating large spatial differences in groundwater responses, and increased after peak flow, when groundwater levels could be considered to be spatially in a steady state. Our findings indicate that topographic indices are useful to predict median groundwater levels in catchments with low-permeability soils and that the TWI assumptions are best met when groundwater levels change slowly.

  • 38. Rinderer, Michael
    et al.
    Kollegger, Andrea
    Fischer, Benjamin M. C.
    Staehli, Manfred
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Sensing with boots and trousers qualitative field observations of shallow soil moisture patterns2012In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 26, no 26, p. 4112-4120Article in journal (Refereed)
    Abstract [en]

    While soil moisture patterns can be interesting traits to investigate spatio-temporal heterogeneity of catchments relevant for various physical processes of soilatmosphere interaction and soil water redistribution, many of the existing methods to capture spatial patterns are time consuming, expensive or need site-specific calibration. In this study we present a quick and inexpensive supplementary field method for classifying soil wetness in wet environments. The seven wetness classes are based on qualitative indicators, which one can touch, hear or see on the soil surface. To counter critics that such qualitative methods are considerably affected by subjectivity, we performed systematic testing of the method by taking qualitative measurements in the field with 20 non-expert raters. We then analyzed these in terms of degree of agreement and assessed the results against gravimetric sampling and time domain reflectometry measurements. In 70% of all classifications raters agreed on the wetness class assigned to the marked sampling locations and in 95% they were not off by more than one wetness class. The seven quantitative wetness classes agreed with gravimetric and time domain reflectometry measurements, although intermediate to wet classes showed an overlap of their range whereas the driest classes showed considerable spread. Despite some potential to optimize the method, it has been shown to be a reliable supplement to existing quantitative techniques for assessing soil moisture patterns in wet environments.

  • 39. Rodhe, Allan
    et al.
    Seibert, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Groundwater dynamics in a till hillslope: flow directions, gradients and delay2011In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 25, no 12, p. 1899-1909Article in journal (Refereed)
    Abstract [en]

    Knowledge of groundwater dynamics is important for the understanding of hydrological controls on chemical processes along the water flow pathways. To increase our knowledge of groundwater dynamics in areas with shallow groundwater, the groundwater dynamics along a hillslope were studied in a boreal catchment in Southern Sweden. The forested hillslope had a 1- to 2-m deep layer of sandy till above bedrock. The groundwater flow direction and slope were calculated under the assumption that the flow followed the slope of the groundwater table, which was computed for different triangles, each defined by three groundwater wells. The flow direction showed considerable variations over time, with a maximum variation of 75 degrees. During periods of high groundwater levels the flow was almost perpendicular to the stream, but as the groundwater level fell, the flow direction became gradually more parallel to the stream, directed in the downstream direction. These findings are of importance for the interpretation of results from hillslope transects, where the flow direction usually is assumed to be invariable and always in the direction of the hillslope. The variations in the groundwater flow direction may also cause an apparent dispersion for groundwater-based transport. In contrast to findings in several other studies, the groundwater level was most responsive to rainfall and snowmelt in the upper part of the hillslope, while the lower parts of the slope reached their highest groundwater level up to 40 h after the upper parts. This can be explained by the topography with a wetter hollow area in the upper part.

  • 40.
    Seibert, J.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Beven, K. J.
    Gauging the ungauged basin: how many discharge measurements are needed?2009In: Hydrology and Earth System Sciences, Vol. 13, no 6, p. 883-892Article in journal (Refereed)
    Abstract [en]

    Runoff estimation in ungauged catchments is probably one of the most basic and oldest tasks of hydrologists. This long-standing issue has received increased attention recently due to the PUB (Prediction in Ungauged Basins) initiative. Given the challenges of predicting runoff for ungauged catchments one might argue that the best course of action is to take a few runoff measurements. In this study we explored how implementing such a procedure might support predictions in an ungauged basin. We used a number of monitored Swedish catchments as hypothetical ungauged basins where we pretended to start with no runoff data and then added different sub-sets of the available data to constrain a simple catchment model. These sub-sets consisted of a limited number of single runoff measurements; in other words these data represent what could be measured with limited efforts in an ungauged basin. We used a Monte Carlo approach and predicted runoff as a weighted ensemble mean of simulations using acceptable parameter sets. We found that the ensemble prediction clearly outperformed the predictions using single parameter sets and that surprisingly little runoff data was necessary to identify model parameterizations that provided good results for the 'ungauged' test periods. These results indicated that a few runoff measurements can contain much of the information content of continuous runoff time series. However, the study also indicated that results may differ significantly between catchments and also depend on the days chosen for taking the measurements.

  • 41.
    Seibert, J.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Bishop, K.
    Nyberg, L.
    Rodhe, A.
    Water storage in a till catchment. I: Distributed modelling and relationship to runoff2011In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 25, no 25, p. 3937-3949Article in journal (Refereed)
    Abstract [en]

    Although water storage is an important variable to understand the hydrological functioning of a catchment, it is challenging to estimate the total water storage in a catchment. Catchment water storage can be estimated on the basis of water balance, but this approach is prone to errors in the different water balance terms. Here, an approach is presented to estimate the daily dynamics of catchment-wide soil water and groundwater storage on the basis of groundwater-level observations, soil properties and an assumption of hydrological equilibrium above the water table. This approach was applied to a 6300-m2 till catchment in Southwest Sweden. The predicted mean catchment water storage between April 1991 and June 1992 was 210mm and ranged from 190 to 260mm. The estimated water storage followed runoff rates closely especially during recession periods. On average, 79% of the water storage was held in the unsaturated zone, and the remaining 21% was groundwater, but this proportion varied strongly with runoff and total storage. During dry conditions, unsaturated storage accounted for at maximum 95% of the water storage; during wet conditions, this number dropped to 40%. Copyright (c) 2011 John Wiley & Sons, Ltd.

  • 42.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Grabs, Thomas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    Köhler, S.
    Department of Aqautic Sciences and Assessment, Swedish University of Agricultural Sciences.
    Laudon, H.
    Department of Forest Ecology and Management,Swedish University of Agricultural Sciences.
    Winterdahl, M.
    Department of Aqautic Sciences and Assessment. Swedish University of Agricultural Sciences.
    Bishop, K.
    Department of Aqautic Sciences and Assessment. Swedish University of Agricultural Sciences.
    Linking soil- and stream-water chemistry based on a Riparian Flow-Concentration Integration Model2009In: Hydrology and earth system sciences, ISSN 1607-7938, Vol. 13, no 12, p. 2287-2297Article in journal (Refereed)
    Abstract [en]

    The riparian zone, the last few metres of soil through which water flows before entering a gaining stream, has been identified as a first order control on key aspects of stream water chemistry dynamics. We propose that the distribution of lateral flow of water across the vertical profile of soil water chemistry in the riparian zone provides a conceptual explanation of how this control functions in catchments where matrix flow predominates. This paper presents a mathematical implementation of this concept as well as the model assumptions. We also present an analytical solution, which provides a physical basis for the commonly used power-law flow-load equation. This approach quantifies the concept of riparian control on stream-water chemistry providing a basis for testing the concept of riparian control. By backward calculation of soil-water-chemistry profiles, and comparing those with observed profiles we demonstrate that the simple juxtaposition of the vertical profiles of water flux and soil water chemistry provides a plausible explanation for observed variations in stream water chemistry of several major stream components such as Total Organic Carbon (TOC), magnesium, calcium and chloride. The "static" implementation of the model structure presented here provides a basis for further development to account for seasonal influences and hydrological hysteresis in the representation of hyporheic, riparian, and hillslope processes.

  • 43.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. Uppsala University, Sweden; University of Zurich, Switzerland.
    McDonnell, J. J.
    Gauging the Ungauged Basin: Relative Value of Soft and Hard Data2015In: Journal of hydrologic engineering, ISSN 1084-0699, E-ISSN 1943-5584, Vol. 20, no 1, p. A4014004-Article in journal (Refereed)
    Abstract [en]

    The long-standing issue of hydrological predictions in ungauged basins has received increased attention due to the recent International Association of Hydrological Sciences (IAHS) decade on predictions in ungauged basins (PUB). Since the outset of PUB, many have noted that the best way to confront an ungauged basin is to first make some basic streamflow measurements. This study explores the value of a rudimentary gauging campaign for making predictions in an ungauged basin. The well-studied Maimai watershed in New Zealand was used as a hypothetical ungauged basin, and this study was designed to start with no runoff data and add iteratively different subsets of the available data to constrain the calibration of a simple three-reservoir conceptual catchment model. These subsets included single runoff events or a limited number of point values-in other words, what could be measured with limited, campaign-like field efforts in an ungauged basin. In addition, different types of soft data were explored to constrain the model calibration. Model simulations were validated using the available runoff data from different years. It was found that surprisingly little runoff data were necessary to derive model parameterizations that provided good results for the validation periods, especially when these runoff data were combined with soft data. The relative value of soft data increased with decreasing amount of streamflow data. The findings from the Maimai watershed suggest that, when starting with no flow information, one event or 10 observations during high flow provide almost as much information as three months of continuously measured streamflow for constraining the calibration of a simple catchment model.

  • 44.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology (INK).
    McDonnell, J. J.
    Land-cover impacts on streamflow: a change-detection modelling approach that incorporates parameter uncertainty2010In: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 55, no 3, p. 316-332Article in journal (Refereed)
    Abstract [en]

    The effect of land-use or land-cover change on stream runoff dynamics is not fully understood. In many parts of the world, forest management is the major land-cover change agent. While the paired catchment approach has been the primary methodology used to quantify such effects, it is only possible for small headwater catchments where there is uniformity in precipitation inputs and catchment characteristics between the treatment and control catchments. This paper presents a model-based change-detection approach that includes model and parameter uncertainty as an alternative to the traditional paired-catchment method for larger catchments. We use the HBV model and data from the HJ Andrews Experimental Forest in Oregon, USA, to develop and test the approach on two small (< 1 km(2)) headwater catchments (a 100% clear-cut and a control) and then apply the technique to the larger 62 km(2) Lookout catchment. Three different approaches are used to detect changes in stream peak flows using: (a) calibration for a period before (or after) change and simulation of runoff that would have been observed without land-cover changes (reconstruction of runoff series); (b) comparison of calibrated parameter values for periods before and after a land-cover change; and (c) comparison of runoff predicted with parameter sets calibrated for periods before and after a land-cover change. Our proof-of-concept change detection modelling showed that peak flows increased in the clear-cut headwater catchment, relative to the headwater control catchment, and several parameter values in the model changed after the clear-cutting. Some minor changes were also detected in the control, illustrating the problem of false detections. For the larger Lookout catchment, moderately increased peak flows were detected. Monte Carlo techniques used to quantify parameter uncertainty and compute confidence intervals in model results and parameter ranges showed rather wide distributions of model simulations. While this makes change detection more difficult, it also demonstrated the need to explicitly consider parameter uncertainty in the modelling approach to obtain reliable results.

  • 45.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    McDonnell, J. J.
    Woodsmith, R. D.
    Effects of wildfire on catchment runoff response: a modelling approach to detect changes in snow-dominated forested catchments2010In: Hydrology Research, ISSN 0029-1277, Vol. 41, no 5, p. 378-390Article in journal (Refereed)
    Abstract [en]

    Wildfire is an important disturbance affecting hydrological processes through alteration of vegetation cover and soil characteristics. The effects of fire on hydrological systems at the catchment scale are not well known, largely because site specific data from both before and after wildfire are rare. In this study a modelling approach was employed for change detection analyses of one such dataset to quantify effects of wildfire on catchment hydrology. Data from the Entiat Experimental Forest (Washington State, US) were used, a conceptual runoff model was applied for pre- and post-fire periods and changes were analyzed in three different ways: reconstruction of runoff series, comparison of model parameters and comparison of simulations using parameter sets calibrated to the two different periods. On average, observed post-fire peak flows were 120% higher than those modelled based on pre-fire conditions. For the post-fire period, parameter values for the snow routine indicated deeper snow packs and earlier and more rapid snowmelt. The net effect of the changes in all parameters was largely increased post-fire peak flows. Overall, the analyses show that change detection modelling provides a viable alternative to the paired-watershed approach for analyzing wildfire disturbance effects on runoff dynamics and supports discussions on changes in hydrological processes.

  • 46.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    McDonnell, Jeffrey J.
    Gauging the ungauged basin: What is the value of limited streamflow measurements? (solicited)2007Conference paper (Other academic)
    Abstract [en]

    The long-standing issue of hydrological predictions for ungauged basins has received increased attention thanks to the PUB imitative. Given all the problems on making predictions in totally ungauged catchments one might argue that the best thing to do in an ungauged basin is to actually take a few runoff measurements. In this study we explored how implementing such a procedure might support predictions in an ungauged basin. We used the well-studied Maimai watershed as a hypothetical ungauged basin where we pretend to start with no runoff data and add different sub-sets of the available data to constrain a simple catchment model. These sub-sets were single runoff events or a limited number of point values; in other words these data represent what could be measured with limited efforts in an ungauged basin. Besides these runoff data we used different types of soft data to constrain the model. We recently presented ‘soft data’ as a general framework to facilitate communication between experimentalist and modeler for new ways to test models and quantify uncertainty, parameter identifiabilty and parameter uncertainty. The model simulations were then validated using the available runoff data from different years. We found that surprisingly little runoff data was necessary to derive model parameterizations which provided good results for the validation periods, especially when these runoff data were combined with soft data. We argue that the improved dialog between experimentalist and modeler may be a necessary next step within the PUB movement for moving from calibration-reliant models to ones grounded in understanding and applicability to ungauged basins.

  • 47.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Stendahl, Johan
    Sørensen, Rasmus
    Topographical influences on soil properties in boreal forests2007In: Geoderma, Vol. 141, no 1-2, p. 139-148Article in journal (Refereed)
  • 48.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Uhlenbrook, S.
    Wagener, T.
    Hydrology education in a changing world Preface2013In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 17, no 4, p. 1393-1399Article in journal (Other academic)
  • 49.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Vis, M. J. P.
    Irrigania - a web based game about sharing water resources2012In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 16, no 8, p. 2523-2530Article in journal (Refereed)
    Abstract [en]

    For teaching about collaboration and conflicts with regard to shared water resources, various types of games offer valuable opportunities. Single-player computer games often give much power to the player and ignore the fact that the best for some group might be difficult to achieve in reality if the individuals have their own interests. Here we present a new game called Irrigania, which aims at representing water conflicts among several actors in a simplified way. While simple in its rules, this game illustrates several game-theoretical situations typical for water-related conflicts. The game has been implemented as a web-based computer game, which allows easy application in classes. First classroom applications of the game indicated that, despite the simple rules, interesting patterns can evolve when playing the game in a class. These patterns can be used to discuss game theoretical considerations related to water resource sharing.

  • 50.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. Uppsala University, Sweden; University of Zurich, Switzerland.
    Vis, Marc J. P.
    How informative are stream level observations in different geographic regions?2016In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 30, no 14, p. 2498-2508Article in journal (Refereed)
    Abstract [en]

    Simple runoff models with a low number of model parameters are generally able to simulate catchment runoff reasonably well, but they rely on model calibration, which makes their use in ungauged basins challenging. In a previous study it has been shown that a limited number of streamflow measurements can be quite informative for constraining runoff models. In practice, however, instead of performing such repeated flow measurements, it might be easier to install a stream level logger. Here, a dataset of 600+ gauged basins in the USA was used to study how well models perform when only stream level data, rather than streamflow data, are available. A runoff model (the HBV model) was calibrated assuming that only stream level observations were available, and the simulations were evaluated on the full observed streamflow record. The results indicate that stream level data alone can already provide surprisingly good model simulation results in humid catchments, whereas in arid catchments some form of quantitative information (e.g. a streamflow observation or a regional average value) is needed to obtain good results. These results are encouraging for hydrological observations in data scarce regions as level observations are much easier to obtain than streamflow measurements. Based on runoff modelling, it might even be possible to derive streamflow time series from the level data obtained from loggers, satellites or community-based approaches.

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