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  • 1. Ahmad, Nawaz
    et al.
    Wörman, Anders
    Sanchez-Vila, Xavier
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Bottacin-Busolin, Andrea
    Hellevang, Helge
    Injection of CO2-saturated brine in geological reservoir: A way to enhanced storage safety2016In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 54, p. 129-144Article in journal (Refereed)
    Abstract [en]

    Injection of free-phase supercritical CO2 into deep geological reservoirs is associated with risk of considerable return flows towards the land surface due to the buoyancy of CO2, which is lighter than the resident brine in the reservoir. Such upward movements can be avoided if CO2 is injected in the dissolved phase (CO2aq). In this work, injection of CO2-saturated brine in a subsurface carbonate reservoir was modelled. Physical and geochemical interactions of injected low-pH CO2-saturated brine with the carbonate minerals (calcite, dolomite and siderite) were investigated in the reactive transport modelling. CO2-saturated brine, being low in pH, showed high reactivity with the reservoir minerals, resulting in a significant mineral dissolution and CO2 conversion in reactions. Over the injection period of 10yr, up to 16% of the injected CO2 was found consumed in geochemical reactions. Sorption included in the transport analysis resulted in additional quantities of CO2 mass stored. However, for the considered carbonate minerals, the consumption of injected CO2aq was found mainly in the form of ionic trapping.

  • 2. Alekseeva, Irina
    et al.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Schrum, Corinna
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Reproducing the Aral Sea water budget and sea-groundwater dynamics between 1979 and 1993 using a coupled 3-D sea-ice-groundwater model2009In: Journal of Marine Systems, Vol. 76, no 3, p. 296-309Article in journal (Refereed)
    Abstract [en]

    We have developed the 3-D sea-ice model, ECOSMO, into a coupled sea-ice–groundwater model and investigated the factors that may have influenced the groundwater–seawater interactions and the water balance of the shrinking Aral Sea. During the simulation period, 1979–1993, the model successfully reproduced the rapid Aral Sea level drop, surface area decrease, coastline position changes and increasing salinization of the Aral Sea. Model predictions of evaporation and groundwater inflow were also consistent with independent estimations. Model results indicated that the net groundwater inflow to the Aral Sea may have increased by 10% or more as a direct effect of the sea level lowering. Furthermore, model scenario tests showed that in comparison with a basic scenario, in which salinity effects were accounted for, not accounting for such effects resulted in considerable changes in ice formation and winter thermal conditions, which in turn influenced the thermo- and hydrodynamics and fresh water air-sea fluxes in the Aral Sea. As a result, the zero-salinity scenario predicted higher evaporation rates and an accelerated sea level lowering by up to 2 cm/yr, in comparison with the basic scenario. Model results showed that increased groundwater inflow to the sea may have influenced the Aral Sea salinity distribution since the 1990's. Our results emphasise the importance of taking into account both baroclinic hydrodynamics, sea-ice dynamics and as well as potentially increased future groundwater-related salinity effects in order to accurately estimate the Aral Sea water balance. More generally, models that can handle such highly dynamic systems may have a realistic potential for making detailed assessments of sea characteristics under the influence of climate and hydrological cycle changes.

  • 3.
    Andersson, Ingela
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Petersson, Mona
    Saving the Baltic Sea, the Inland Waters of Its Drainage Basin, or Both?: Spatial Perspectives on Reducing P-Loads in Eastern Sweden2014In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 43, no 7, p. 914-925Article in journal (Refereed)
    Abstract [en]

    Nutrient loads from inland sources to the Baltic Sea and adjacent inland waters need to be reduced in order to prevent eutrophication and meet requirements of the European Water Framework Directive (WFD) and the Baltic Sea Action Plan (BSAP). We here investigate the spatial implications of using different possible criteria for reducing water-borne phosphorous (P) loads in the Northern Baltic Sea River Basin District (NBS-RBD) in Sweden. Results show that most catchments that have a high degree of internal eutrophication do not express high export of P from their outlets. Furthermore, due to lake retention, lake catchments with high P-loads per agricultural area (which is potentially of concern for the WFD) did not considerably contribute to the P-loading of the Baltic Sea. Spatially uniform water quality goals may, therefore, not be effective in NBS-RBD, emphasizing more generally the need for regional adaptation of WFD and BSAP-related goals.

  • 4.
    Andersson, Ingela
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Petersson, Mona
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Impact of the European Water Framework Directive on local-level water management: Case study Oxunda Catchment, Sweden2012In: Land use policy, ISSN 0264-8377, E-ISSN 1873-5754, Vol. 29, no 1, p. 73-82Article in journal (Refereed)
    Abstract [en]

    The Water Framework Directive (WFD) of the European Union provides a common framework for waterpolicy that focuses on holistic and integrated water management in river basins. In many member states,implementation of the WFD has shifted the main responsibility for local water issues from the municipallevel to the regional or supra-regional levels. In this study, we investigated how the implementation of theWFD has influenced local-level water management including the interpretation of the new environmentalquality standards. Specifically, we considered Sweden, which has traditionally had relatively stronggovernance at the municipal level. Because a sufficient amount of time has now passed for evaluationof WFD-related effects on operational water handling, we interviewed individuals directly involved inwater planning and land use planning at the municipal level in one sub catchment in the Northern BalticSea River Basin District of Sweden, as well as representatives for superior levels and associations. Despitedivergent views regarding the priority of water issues in physical planning among the local-level plannersinterviewed, they had all participated in successful inter-municipal pre-WFD collaboration projects.Although such collaborations could help increase the understanding and acceptance of WFD-related goalsand costs, as well as facilitate conflict solving, as shown in the Oxunda Catchment, they have not gainedmuch attention in the WFD implementation process. Additionally, physical planners have generally beenreluctant to accept new environmental quality standards resulting from WFD implementation, in partbecause they lack precise definitions, but also because they could challenge the municipal routine ofweighing various objectives against each other. Furthermore, despite WFD-related increases in ambitionlevels, lack of resource improvements at the municipal level were identified as potential problems by local environmental planners.

  • 5.
    Asokan, Shilpa M.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Vapor flux by evapotranspiration: effects of changes in climate, land-use and water-use2010In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 115, no D24Article in journal (Refereed)
    Abstract [en]

    Enhanced evapotranspiration (ET) over irrigated land and associated latent heat flux change can modify the climate. Model studies of such climate change effects of irrigation are commonly based on land use parameterizations, in terms of irrigated land area, or land area equipped for irrigation. Actual ET change, however, may also be driven by water use change in addition to land use change. This study quantifies and compares ET changes due to changes in climate, land use, and water use from the preirrigation period 1901–1955 to the recent period 1990–2000 (with irrigation) for the example case of Mahanadi River Basin (MRB) in India. The results show that actual water use per unit area of irrigated land may vary greatly over a hydrological drainage basin. In MRB, much higher water use per irrigated land unit in the downstream humid basin parts leads to higher vapor flux by ET, and irrigation‐induced ET flux change, than in the upstream, water‐stressed basin parts. This is consistent with water supply limitations in water‐stressed basins. In contrast, the assumption in land use−based models that irrigation maintains high soil moisture contents can imply higher modeled water use and therefore also higher modeled ET fluxes under dry conditions than under humid conditions. The present results indicate water use as an important driver of regional climate change, in addition to land use and greenhouse gas‐driven changes.

  • 6.
    Asokan, Shilpa M.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Rogberg, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Bring, Arvid
    Stockholm University, Faculty of Science, Department of Physical Geography. University of New Hampshire, USA.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Climate model performance and change projection for freshwater fluxes: comparison for irrigated areas in Central and South Asia2016In: Journal of Hydrology Regional Studies, ISSN 1070-9428, E-ISSN 1857-8489, Vol. 5, p. 48-65Article in journal (Refereed)
    Abstract [en]

    Study region: The large semi-arid Aral Region in Central Asia and the smaller tropical Mahanadi River Basin (MRB) in India. Study focus: Few studies have so far evaluated the performance of the latest generation ofglobal climate models on hydrological basin scales. We here investigate the performanceand projections of the global climate models in the Coupled Model Intercomparison Project, Phase 5 (CMIP5) for freshwater fluxes and their changes in two regional hydrological basins, which are both irrigated but of different scale and with different climate. New hydrological insights for the region: For precipitation in both regions, model accuracy relative to observations has remained the same or decreased in successive climate model generations until and including CMIP5. No single climate model out-performs other models across all key freshwater variables in any of the investigated basins. Scale effects are not evident from global model application directly to freshwater assessment for the two basins of widely different size. Overall, model results are less accurate and more uncertain for freshwater fluxes than for temperature, and particularly so for model-implied water storage changes. Also, the monsoon-driven runoff seasonality in MRB is not accurately reproduced. Model projections agree on evapotranspiration increase in both regions until the climatic period 2070–2099. This increase is fed by precipitation increase in MRB and by runoff water (thereby decreasing runoff) in the Aral Region.

  • 7. Augustsson, A.
    et al.
    Söderberg, Uddh T.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Åström, M.
    Olofsson, B.
    Balfors, B.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography.
    The risk of overestimating the risk-metal leaching to groundwater near contaminated glass waste deposits and exposure via drinking water2016In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 566, p. 1420-1431Article in journal (Refereed)
    Abstract [en]

    This study investigates metal contamination patterns and exposure to Sb, As, Ba, Cd and Pb via intake of drinking water in a region in southeastern Sweden where the production of artistic glass has resulted in a large number of contaminated sites. Despite high total concentrations of metals in soil and groundwater at the glassworks sites properties, all drinking water samples from households with private wells, located at a 30-640 m distance from a glassworks site, were below drinking water criteria from the WHO for Sb, As, Ba and Cd. A few drinking water samples showed concentrations of Pb above the WHO guideline, but As was the only element found in concentrations that could result in human exposure near toxicological reference values. An efficient retention of metals in the natural soil close to the source areas, which results in a moderate impact on local drinking water, is implied. Firstly, by the lack of significant difference in metal concentrations when comparing households located upstream and downstream of the main waste deposits, and secondly, by the lack of correlation between the metal concentration in drinking water and distance to the nearest glassworks site. However, elevated Pb and Cd concentrations in drinking water around glassworks sites when compared to regional groundwater indicate that diffuse contamination of the soils found outside the glassworks properties, and not only the glass waste landfills, may have a significant impact on groundwater quality. We further demonstrate that different mobilization patterns apply to different metals. Regarding the need to use reliable data to assess drinking water contamination and human exposure, we finally show that the conservative modelling approaches that are frequently used in routine risk assessments may result in exposure estimates many times higher than those based on measured concentrations in the drinking water that is actually being used for consumption.

  • 8. Bayer-Raich, Martí
    et al.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Teutsch, Georg
    Breakthrough of attenuating contaminant plumes in pumping wells: Analytical model and implications for integral pumping tests.2009In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 45, p. W02413-Article in journal (Refereed)
    Abstract [en]

    Monitoring of contaminant plumes and predicting their future fate are essential for effective management of groundwater contaminants. Solute breakthrough curves from operating pumping wells can provide information on the water quality in relatively large aquifer regions, which may be unavailable to instrumentation and direct measurement for practical and/or economical reasons. Relations between spatially varying aquifer concentrations C0(x, y) initially surrounding a well and temporally varying concentrations of subsequently extracted well water, Cp(t), then need to be quantified. However, limited applicability of analytical expressions and numerical inaccuracies related to solving transport equations for converging flow fields hamper such quantifications even in homogeneous aquifers. We use a stream-tube approach and provide a general problem formulation that accounts for first-order degradation and linear, instantaneous, sorption/retardation in heterogeneous aquifers. An analytical expression is obtained for homogeneous aquifer conditions (in the well vicinity), relating any given initial C0(x, y) function and the subsequent contaminant breakthrough Cp(t) in the well. Results for wide plumes subject to first-order degradation show that concentrations at the extraction well will increase as a function of pumping time. This increase is despite the fact that late-time data reflect longer transport paths (to the well), along which mass is removed through degradation. We also derive unique solutions for the inverse problem, in particular considering how the average contaminant concentration Cav (averaged along a control plane through the well within its capture zone, perpendicular to the mean groundwater flow direction) depends on the measurable Cp(t). The solutions demonstrate that the longer the pumping time, the more sensitive the solutions for Cav become to degradation rate constants, which if needed can be determined in situ using multiple control planes.

  • 9. Bayer-Raich, Martí
    et al.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Teutsch, Georg
    Comment on “Analysis of groundwater contamination using concentration-time series recorded during an integral pumping test: Bias introduced by strong concentration gradients within the plume” by Allelign Zeru and Gerhard Schäfer2007In: Journal of Contaminant Hydrology, ISSN 0169-7722, Vol. 90, no 3-4, p. 240-251Article in journal (Refereed)
    Abstract [en]

    We consider the results of a recent paper in this journal [Zeru, A. and Schäfer, G., 2005. Analysis of groundwater contamination using concentration–time series recorded during an integral pumping test: Bias introduced by strong concentration gradients within the plume. Journal of Contaminant Hydrology 81 (2005) 106–124], which addresses the field-scale characterisation of contaminant plumes in groundwater. There, it is concluded that contaminant concentration gradients can bias Integral Pumping Test (IPT) interpretations considerably, in particular if IPTs are conducted in advective fronts of contaminant plumes. We discuss implications of this setting and also argue that the longitudinal and transverse dispersivities used in the examples of Zeru and Schäfer (2005) of up to 30 m and 3 m, respectively, are generally very high for the here relevant capture zone scale (b20 m). However, regardless of both longitudinal and transverse concentration gradients, we further show through a counter-example that IPT results are unbiased as long as the concentration attenuation along the flow direction is linear over the capture zone extent.

  • 10.
    Bring, Arvid
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography. University of New Hampshire, USA.
    Asokan, Shilpa M.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jaramillo, Fernando
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Levi, Lea
    Stockholm University, Faculty of Science, Department of Physical Geography. KTH Royal Institute of Technology, Sweden; University of Split, Croatia.
    Pietroń, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Prieto, Carmen
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Rogberg, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Implications of freshwater flux data from the CMIP5 multimodel output across a set of Northern Hemisphere drainage basins2015In: Earths Future, ISSN 2328-4277, Vol. 3, no 6, p. 206-217Article in journal (Refereed)
    Abstract [en]

    The multimodel ensemble of the Coupled Model Intercomparison Project, Phase 5 (CMIP5) synthesizes the latest research in global climate modeling. The freshwater system on land, particularly runoff, has so far been of relatively low priority in global climate models, despite the societal and ecosystem importance of freshwater changes, and the science and policy needs for such model output on drainage basin scales. Here we investigate the implications of CMIP5 multimodel ensemble output data for the freshwater system across a set of drainage basins in the Northern Hemisphere. Results of individual models vary widely, with even ensemble mean results differing greatly from observations and implying unrealistic long-term systematic changes in water storage and level within entire basins. The CMIP5 projections of basin-scale freshwater fluxes differ considerably more from observations and among models for the warm temperate study basins than for the Arctic and cold temperate study basins. In general, the results call for concerted research efforts and model developments for improving the understanding and modeling of the freshwater system and its change drivers. Specifically, more attention to basin-scale water flux analyses should be a priority for climate model development, and an important focus for relevant model-based advice for adaptation to climate change.

  • 11.
    Bring, Arvid
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Water Information and Water Security in the Arctic2015In: The New Arctic / [ed] B. Evengård, J. Nymand Larsen, Ø. Paasche, Springer, 2015, p. 225-238Chapter in book (Refereed)
    Abstract [en]

    Water is common to many environmental changes that are currently observed in the Arctic. To manage environmental change, and related water security challenges that are rising in the Arctic, adequate water information and monitoring is critical. Although water information systems have been deteriorating in the Arctic, there are still opportunities to combine existing data to inform policy decisions on how to manage water security. Furthermore, implementing a set of water security indicators can help identify areas of concern within the region. However, accessible climate change information is not always relevant for the scales of policymaking. In addition, improved representation of water on land in climate models is needed to better inform adaptation.

  • 12. Chalov, Sergey R.
    et al.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Kasimov, Nikolay S.
    Romanchenko, Anna O.
    Pietroń, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Thorslund, Josefin
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Promakhova, Ekaterina V.
    Spatio-temporal variation of sediment transport in the Selenga River Basin, Mongolia and Russia2015In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 73, no 2, p. 663-680Article in journal (Refereed)
    Abstract [en]

    Many Asian rivers have been intensively used to boost economic growth, resulting in sudden and drastic changes in sediment transport patterns. However, a few rivers are still undisturbed. The present paper considers the unregulated Selenga River and its basin, located in Russia and Mongolia. The river contributes to 50 % of the total inflow to Lake Baikal. Pending scientific challenges include the quantification of sediment loads and erosion-deposition patterns along the Selenga River system, the understanding of suspended particulate matter composition and the importance of peak flow events for total sediment discharge and heavy metal transport. Field data and hydraulic modeling converge on showing that peak flow events during spring and summer contribute to the main part (70-80 %) of the annual sediment and pollution loads in upstream parts of the basin. The Selenga River carries mostly silt and sand. The average particle size differs by a factor of four between summer floods and base flow periods. The low amount of particulate organic matter (ranging between 1 and 16 % in the studied rivers) is consistent with the significant role of sediments originating from mining areas and in-channel sources. The bed load transport in the downstream part of the river basin is high (up to 50 % of the total transport), and channel storage plays an important role in the total sediment transport to Lake Baikal. Reported statistically significant multi-decadal declines in sediment fluxes in the downstream Selenga River can be attributed to the abandonment of cultivated lands and (most likely) to changing hydroclimatic factors.

  • 13. Chalov, Sergey R.
    et al.
    Tsyplenkov, Anatolii S.
    Pietron, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Chalova, Aleksandra S.
    Shkolnyi, Danila I.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Maerker, Michael
    Sediment transport in headwaters of a volcanic catchment-Kamchatka Peninsula case study2017In: Frontiers of Earth Science, ISSN 2095-0195, Vol. 11, no 3, p. 565-578Article in journal (Refereed)
    Abstract [en]

    Due to specific environmental conditions, headwater catchments located on volcanic slopes and valleys are characterized by distinctive hydrology and sediment transport patterns. However, lack of sufficient monitoring causes that the governing processes and patterns in these areas are rarely well understood. In this study, spatiotemporal water discharge and sediment transport from upstream sources was investigated in one of the numerous headwater catchments located in the lahar valleys of the Kamchatka Peninsula Sukhaya Elizovskaya River near Avachinskii and Koryakskii volcanoes. Three different subcatchments and corresponding channel types (wandering rivers within lahar valleys, mountain rivers within volcanic slopes and rivers within submountain terrains) were identified in the studied area. Our measurements from different periods of observations between years 2012-2014 showed that the studied catchment was characterized by extreme diurnal fluctuation of water discharges and sediment loads that were influenced by snowmelt patterns and high infiltration rates of the easily erodible lahar deposits. The highest recorded sediment loads were up to 9.10(4) mg/L which was related to an increase of two orders of magnitude within a one day of observations. Additionally, to get a quantitative estimate of the spatial distribution of the eroded material in the volcanic substrates we applied an empirical soil erosion and sediment yield model-modified universal soil loss equation (MUSLE). The modeling results showed that even if the applications of the universal erosion model to different non-agricultural areas (e.g., volcanic catchments) can lead to irrelevant results, the MUSLE model delivered might be acceptable for non-lahar areas of the studied volcanic catchment. Overall the results of our study increase our understanding of the hydrology and associated sediment transport for prediction of risk management within headwater volcanic catchments.

  • 14. Chalov, Sergey
    et al.
    Thorslund, Josefin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Kasimov, Nikolay
    Aybullatov, Denis
    Ilyicheva, Elena
    Karthe, Daniel
    Kositsky, Alexey
    Lychagin, Mikhail
    Nittrouer, Jeff
    Pavlov, Maxim
    Pietron, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Shinkareva, Galina
    Tarasov, Mikhail
    Garmaev, Endon
    Akhtman, Yosef
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    The Selenga River delta: a geochemical barrier protecting Lake Baikal waters2017In: Regional Environmental Change, ISSN 1436-3798, E-ISSN 1436-378X, Vol. 17, no 7, p. 2039-2053Article in journal (Refereed)
    Abstract [en]

    The protection of Lake Baikal and the planning of water management measures in the Selenga River Basin require a comprehensive understanding of the current state and functioning of the delta’s ecosystem and hydrogeochemical processes. This is particularly relevant in light of recent and expected future changes involving both the hydrology and water quality in the Lake Baikal basin causing spatiotemporal changes in water flow, morphology, and transport of sediments and metals in the Selenga River delta and thus impacting on delta barrier functions. The central part of the delta had been characterized by sediment storage, especially along the main channels, causing a continuous lift of the delta surface by about 0.75 cm/year−1. Theses morphological changes have a significant impact on hydrological conditions, with historical shifts in the bulk discharge from the left to the right parts of the delta which is distinguished by a relatively high density of wetlands. Regions with a high density of wetlands and small channels, in contrast to main channel regions, show a consistent pattern of considerable contaminant filtering and removal (between 77 and 99 % for key metals), during both high-flow and low-flow conditions. The removal is associated with a significant concentration increase (2–3 times) of these substances in the bottom sediment. In consequence, geomorphological processes, which govern the partitioning of flow between different channel systems, may therefore directly govern the barrier function of the delta.

  • 15.
    Chasset, Coralie
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Erlström, Mikael
    Cvetkovic, Vladimir
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Scenario simulations of CO(2) injection feasibility, plume migration and storage in a saline aquifer, Scania, Sweden2011In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 5, no 5, p. 1303-1318Article in journal (Refereed)
    Abstract [en]

    Deep saline aquifers have large capacity for geological CO(2) storage, but are generally not as well characterized as petroleum reservoirs. We here aim at quantifying effects of uncertain hydraulic parameters and uncertain stratigraphy on CO(2) injectivity and migration, and provide a first feasibility study of pilot-scale CO(2) injection into a multilayered saline aquifer system in southwest Scania, Sweden. Four main scenarios are developed, corresponding to different possible interpretations of available site data. Simulation results show that, on the one hand, stratigraphic uncertainty (presence/absence of a thin mudstone/claystone layer above the target storage formation) leads to large differences in predicted CO(2) storage in the target formation at the end of the test (ranging between 11% and 98% of injected CO(2) remaining), whereas other parameter uncertainty (in formation and cap rock permeabilities) has small impact. On the other hand, the latter has large impact on predicted injectivity, on which stratigraphic uncertainty has small impact. Salt precipitation at the border of the target storage formation affects CO(2) injectivity for all considered scenarios and injection rates. At low injection rates, salt is deposited also within the formation, considerably reducing its availability for CO(2) storage.

  • 16.
    Clason, Caroline C.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Coch, Caroline
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Brugger, K.
    Jansson, Peter
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Rosqvist, Gunhild
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Dye tracing to determine flow properties of hydrocarbon-polluted Rabots glaciar, Kebnekaise, Sweden2015In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 19, no 6, p. 2701-2715Article in journal (Refereed)
    Abstract [en]

    Over 11 000 L of kerosene was deposited on the surface of Rabots glaciar on the Kebnekaise Massif, northern Sweden, following the crash of a Royal Norwegian Air Force aircraft in March 2012. An environmental monitoring programme was subsequently commissioned, including a series of dye tracing experiments during the 2013 melt season, conducted to investigate the transport of pollutants through the glacier hydrological system. This experimental set-up provided a basis from which we could gain new insight into the internal hydrological system of Rabots glaciar. Results of dye tracing experiments reveal a degree of homogeneity in the topology of the drainage system throughout July and August, with an increase in efficiency as the season progresses, as reflected by decreasing temporary storage and dispersivity. Early onset of melting likely led to formation of an efficient, discrete drainage system early in the melt season, subject to decreasing sinuosity and braiding as the season progressed. Four distinct meltwater flow regimes are identified to summarize the temporal and spatial evolution of the system. Analysis of turbidity-discharge hysteresis further supports the formation of discrete, efficient drainage, with clockwise diurnal hysteresis suggesting easy mobilization of readily available sediments in channels. Dye injection immediately downstream of the pollution source zone reveals prolonged storage of dye followed by fast, efficient release. Twinned with a low dye recovery, and supported by sporadic detection of hydrocarbons in the proglacial river, we suggest that meltwater, and thus pollutants in solution, may be released periodically through an efficient, and likely pressurized, hydrological system within the upper reaches of the glacier.

  • 17.
    Darracq, Amelie
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Persson, Klas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Prieto, Carmen
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Quantification of advective solute travel times and mass transport through hydrological catchments2010In: Environmental Fluid Mechanics, ISSN 1567-7419, E-ISSN 1573-1510, Vol. 10, no 1-2, p. 103-120Article in journal (Refereed)
    Abstract [en]

    This study has investigated and outlined the possible quantification and mapping of the distributions of advective solute travel times through hydrological catchments. These distributions are essential for understanding how local water flow and solute transport and attenuation processes affect the catchment-scale transport of solute, for instance with regard to biogeochemical cycling, contamination persistence and water quality. The spatial and statistical distributions of advective travel times have been quantified based on reported hydrological flow and mass-transport modeling results for two coastal Swedish catchments. The results show that the combined travel time distributions for the groundwater-stream network continuum in these catchments depend largely on the groundwater system and model representation, in particular regarding the spatial variability of groundwater hydraulic parameters (conductivity, porosity and gradient), and the possible contributions of slower/deeper groundwater flow components. Model assumptions about the spatial variability of groundwater hydraulic properties can thus greatly affect model results of catchment-scale solute spreading. The importance of advective travel time variability for the total mass delivery of naturally attenuated solute (tracer, nutrient, pollutant) from a catchment to its downstream water recipient depends on the product of catchment-average physical travel time and attenuation rate.

  • 18.
    Darracq, Amelie
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Persson, Klas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Prieto, Carmen
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Scale and model resolution effects on the distributions of advective solute travel times in catchments2010In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 24, no 12, p. 1697-1710Article in journal (Refereed)
    Abstract [en]

    Advective solute travel times and their distributions in hydrological catchments are useful descriptors of the dynamics and variation of the physical mass transport among and along the different source-to-recipient pathways of solute transport through the catchments. This article investigates the scale dependence and the effects of model and data resolution on the quantification of advective travel times and their distributions in the Swedish catchment areas of Norrström and Forsmark. In the surface water networks of the investigated (sub)catchments, the mean advective travel time increases with (sub)catchment scale, whereas the relative travel time variability around the mean value (coefficient of variation, CV) is scale-invariant and insensitive to model resolution. In the groundwater and for the whole (sub)catchments, both the mean value and the CV of travel times are scale-invariant, but sensitive to model resolution and accuracy. Such quantifications and results of advective travel times constitute important steps in the development of improved understanding and modelling of nutrient, pollutant and tracer transport through catchments.

  • 19.
    Dessirier, Benoît
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Frampton, Andrew
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Fransson, A.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Modeling early in situ wetting of a compacted bentonite buffer installed in low permeable crystalline bedrock2016In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 52, no 8, p. 6207-6221Article in journal (Refereed)
    Abstract [en]

    The repository concept for geological disposal of spent nuclear fuel in Sweden and Finland is planned to be constructed in sparsely fractured crystalline bedrock and with an engineered bentonite buffer to embed the waste canisters. An important stage in such a deep repository is the postclosure phase following the deposition and the backfilling operations when the initially unsaturated buffer material gets hydrated by the groundwater delivered by the natural bedrock. We use numerical simulations to interpret observations on buffer wetting gathered during an in situ campaign, the Bentonite Rock Interaction Experiment, in which unsaturated bentonite columns were introduced into deposition holes in the floor of a 417 m deep tunnel at the Aspo Hard Rock Laboratory in Sweden. Our objectives are to assess the performance of state-of-the-art flow models in reproducing the buffer wetting process and to investigate to which extent dependable predictions of buffer wetting times and saturation patterns can be made based on information collected prior to buffer insertion. This would be important for preventing insertion into unsuitable bedrock environments. Field data and modeling results indicate the development of a de-saturated zone in the rock and show that in most cases, the presence or absence of fractures and flow heterogeneity are more important factors for correct wetting predictions than the total inflow. For instance, for an equal open-hole inflow value, homogeneous inflow yields much more rapid buffer wetting than cases where fractures are represented explicitly thus creating heterogeneous inflow distributions.

  • 20.
    Dessirier, Benoît
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Frampton, Andrew
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    A global sensitivity analysis of two-phase flow between fractured crystalline rock and bentonite with application to spent nuclear fuel disposal2015In: Journal of Contaminant Hydrology, ISSN 0169-7722, E-ISSN 1873-6009, Vol. 182, p. 25-35Article in journal (Refereed)
    Abstract [en]

    Geological disposal of spent nuclear fuel in deep crystalline rock is investigated as a possible long term solution in Sweden and Finland. The fuel rods would be cased in copper canisters and deposited in vertical holes in the floor of deep underground tunnels, embedded within an engineered bentonite buffer. Recent experiments at the Äspö Hard Rock Laboratory (Sweden) showed that the high suction of unsaturated bentonite causes a de-saturation of the adjacent rock at the time of installation, which was also independently predicted in model experiments. Remaining air can affect the flow patterns and alter bio-geochemical conditions, influencing for instance the transport of radionuclides in the case of canister failure. However, thus far, observations and model realizations are limited in number and do not capture the conceivable range and combination of parameter values and boundary conditions that are relevant for the thousands of deposition holes envisioned in an operational final repository.

    In order to decrease this knowledge gap, we introduce here a formalized, systematic and fully integrated approach to study the combined impact of multiple factors on air saturation and dissolution predictions, investigating the impact of variability in parameter values, geometry and boundary conditions on bentonite buffer saturation times and on occurrences of rock de-saturation. Results showed that four parameters consistently appear in the top six influential factors for all considered output (target) variables: the position of the fracture intersecting the deposition hole, the background rock permeability, the suction representing the relative humidity in the open tunnel and the far field pressure value. The combined influence of these compared to the other parameters increases as one targets a larger fraction of the buffer reaching near-saturation. Strong interaction effects were found, which means that some parameter combinations yielded results (e.g., time to saturation) far outside the range of results obtained by the rest of the scenarios. This study also addresses potential air trapping by dissolution of part of the initial air content of the bentonite, showing that neglecting gas flow effects and trapping could lead to significant underestimation of the remaining air content and the duration of the initial aerobic phase of the repository.

  • 21.
    Dessirier, Benoît
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Frampton, Andrew
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Impact of near-wall rock characteristics on bentonite buffer wetting: In situ study of nuclear fuel deposition holes in deep bedrockManuscript (preprint) (Other academic)
  • 22.
    Dessirier, Benoît
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Frampton, Andrew
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    MODELING TWO-PHASE-FLOW INTERACTIONS ACROSS A BENTONITE CLAY AND FRACTURED ROCK INTERFACE2014In: Nuclear Technology, ISSN 0029-5450, E-ISSN 1943-7471, Vol. 187, no 2, p. 147-157Article in journal (Refereed)
    Abstract [en]

    Deep geological repositories are generally considered as suitable environments for final disposal of spent nuclear fuel. In the Swedish and Finnish repository design concept, canisters are to be placed in deep underground tunnels in sparsely fractured crystalline bedrock, in deposition holes in which each canister is embedded with an expansive bentonite-clay-mixture buffer. A set of semigeneric two-dimensional radially symmetric TOUGH2 simulations are conducted to investigate the multiphase dynamics and interactions between water and air in a bentonite-rock environment. The main objective is to identify how sensitive saturation times of bentonite are to the geometry of the rock fractures and to commonly adopted simplifications in the unsaturated flow description such as Richards assumptions. Results show that the location of the intersection between the fracture system and the deposition hole is a key factor affecting saturation times. A potential long-lasting desaturation of the rock matrix close to the bentonite-rock interface is also identified extending up to 10 cm inside the rock. Two-phase-flow models predict systematically longer saturation times compared to a simplified Richards approximation, which is frequently used to represent unsaturated flows. The discrepancy diverges considerably as full saturation is approached.

  • 23.
    Dessirier, Benoît
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Åkesson, Mattias
    Lanyon, Bill
    Frampton, Andrew
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Reconstruction of the water content at an interface between compacted bentonite blocks and fractured crystalline bedrock2017In: Applied Clay Science, ISSN 0169-1317, E-ISSN 1872-9053, Vol. 142, p. 145-152Article in journal (Refereed)
    Abstract [en]

    High-density sodium bentonite combines a low permeability with a swelling behavior, which constitute two important qualities for engineered barriers in geological disposal of spent nuclear fuel. For example, the KBS-3V method developed in Sweden and Finland is planned to include compacted bentonite as the buffer material to embed canisters containing the spent nuclear fuel packages in deposition holes in deep crystalline bedrock. The partially saturated bentonite buffer will then swell as it takes up groundwater from the surrounding rock. It is important to quantify the water content evolution of the installed buffer to correctly predict the development of the swelling pressure and the prevailing conditions (thermal, mechanical, chemical and biological). This study aimed at quantifying the water content profile at the surface of a cylindrical bentonite parcel retrieved after in situ wetting in fractured crystalline bedrock. We demonstrate the possibility of using regression-kriging to quantitatively include spatial information from high-resolution photographs of the retrieved bentonite parcel, where more water saturated areas appear as relatively dark shades, along with bentonite samples, where detailed measurements of water content were performed. The resulting reconstruction is both exact regarding local sample measurements and successful to reproduce features such as intersecting rock fracture traces, visible in the photographs. This level of detail is a key step to gain a deeper understanding of the hydraulic behavior of compacted bentonite barriers in sparsely fractured rock. An improved scanning procedure could further increase the accuracy by reducing errors introduced by the geometrical transformations needed to unfold and stitch the different photographs into a single gray scale map of the bentonite surface. The application of this technique could provide more insights to ongoing and planned experiments with unsaturated bentonite buffers.

  • 24.
    Destouni, G.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Persson, K.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Prieto, C.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, J.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    General quantification of catchment-scale nutrient and pollutant transport through the subsurface to surface and coastal waters2010In: Environmental Science and Technology, ISSN 1086-931X, E-ISSN 1520-6912, Vol. 44, no 6, p. 2048-2055Article in journal (Refereed)
    Abstract [en]

    This study develops a general quantification framework for consistent intermodel and intercatchment comparison of the nutrient and pollutant mass loading from multiple sources in a catchment area to downstream surface and coastal waters. The framework accounts for the wide spectrum of different transport pathways and travel times through the subsurface (soil, groundwater, sediment) and the linked surface (streams, lakes, wetlands) water systems of a catchment. The account is based on key flow partitioning and mass delivery fractions, which can be quantified differently by different flow and transport and reaction models. The framework application is exemplified for two Swedish catchment cases with regard to the transport of phosphorus and of a generic attenuating solute. The results show essential differences in model quantifications of transport pathways and temporal spreading, with important implications for our understanding of cause and effect in the catchment-scale nutrient and pollutant loading to downstream waters.

  • 25.
    Destouni, Georgia
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Asokan, Shilpa M.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Augustsson, Anna
    Linnaeus University, Sweden.
    Balfors, Berit
    The Royal Institute of Technology, Sweden.
    Bring, Arvid
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jaramillo, Fernando
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Johansson, Emma
    Stockholm University, Faculty of Science, Department of Physical Geography. Swedish Nuclear Fuel and Waste Management Co, Sweden.
    Juston, John
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Levi, Lea
    Stockholm University, Faculty of Science, Department of Physical Geography. The Royal Institute of Technology, Sweden; University of Split, Croatia.
    Olofsson, Bo
    The Royal Institute of Technology, Sweden.
    Prieto, Carmen
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Quin, Andrew
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Åström, Mats
    Linnaeus University, Sweden.
    Cvetkovic, Vladimir
    The Royal Institute of Technology, Sweden.
    Needs and means to advance science, policy and management understanding of the freshwater system – A synthesis report2015Report (Other academic)
    Abstract [en]

    Fragmented and inconsistent understanding of the freshwater system limits our ability to achieve water security and sustainability under the human-driven changes occurring in the Anthropocene. To advance system-level understanding of freshwater, gaps and inconsistencies in knowledge, data, representations and links of processes and subsystems need to be identified and bridged under consideration of the freshwater system as a continuous whole. 

    Based on such identification, a freshwater system conceptualization is developed in this report, which emphasizes four essential, yet often neglected system aspects:

    i) Distinction of coastal divergent catchments.

    ii) Four main zones (surface, subsurface, coastal, observation) of different types of freshwater change.

    iii) Water pathways as system-coupling agents that link and partition water change among the four change zones.

    iv) Direct interactions with the anthroposphere as integral system pathways across the change zones.

    We explain and exemplify some key implications of these aspects, identifying in the process also distinct patterns of human-driven changes in large-scale water fluxes and nutrient loads.

    The present conceptualization provides a basis for common inter- and trans-disciplinary understanding and systematic characterization of the freshwater system function and its changes, and of approaches to their modeling and monitoring. This can be viewed and used as a unifying checklist that can advance science, policy and management of freshwater and related environmental changes across various scales and world regions.

  • 26.
    Destouni, Georgia
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Asokan, Shilpa M.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Inland hydro-climatic interaction: Effects of human water use on regional climate2010In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 37, no 18, p. L18402-Article in journal (Refereed)
    Abstract [en]

    This study has quantified the regional evaporation and evapotranspiration changes, and the associated latent heat flux and surface temperature changes in the Central Asian region of the Aral Sea drainage basin and the Aral Sea itself from the pre-1950 period of the 20th century to 1983-2002. The human water use for irrigation yielded an average regional cooling effect of -0.6 degrees C due to increased evapotranspiration and latent heat flux from the irrigated land. The runoff water diverted for irrigation was more than 80% of the pre-1950 runoff into the terminal Aral Sea, and was largely lost from the regional water system by the evapotranspiration increase. The Aral Sea shrank due to this water loss, resulting in decreased evaporation and latent heat flux from the pre-1950 Aral Sea area extent, with an average regional warming effect of 0.5 degrees C. In general, the endorheic (land-internal) runoff and relative consumptive use of irrigation water from that runoff determine the relative inland water area shrinkage, its warming effect, and to what extent the warming counteracts the cooling effect of irrigation. Citation: Destouni, G., S. M. Asokan, and J. Jarsjo (2010), Inland hydro-climatic interaction: Effects of human water use on regional climate.

  • 27.
    Destouni, Georgia
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Basu, Nandita
    Cohen, Matthew J.
    Dahlke, Helen
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jaramillo, Fernando
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jawitz, James W.
    Juston, John
    Karlsson, Elin M.
    Koussis, Antonis D.
    Lyon, Steve
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Mazi, Katerina
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Mård Karlsson, Johanna
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Prieto, Carmen
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Rao, Suresh C.
    van der Velde, Ype
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Vercauteren, Nikki
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Hydro-Biogeochemical and Environmental-Management Functions of Wetland Networks in Landscapes2012In: 9th INTECOL International Wetlands Conference, Wetlands in a Complex World: Conference Abstracts, 2012, p. 915-Conference paper (Other academic)
    Abstract [en]

    A main application goal of ecohydrological science is to amplify opportunities of achieving water quality improvements, biodiversity enhancements and sustainable development, by improved understanding and use of ecosystem properties as a management tool. This paper draws on and synthesizes main result implications for the function and possible enhanced use of wetland networks in the landscape as such a tool, from a series of hydro-biogeochemical and environmental economics studies of nutrient/pollutant loading and abatement in different Swedish hydrological catchments. Results show large potential of wetland networks to reduce the cost of abating nutrient and metal loads within and from hydrological catchments, and emphasize some main research questions for further investigations of actual possibilities to realize this potential. The questions regard in particular the ability of wetland networks to extend the travel times and reduce the uncertainty of hydrological nutrient/pollutant transport through catchments.

    The paper further presents and discusses some main joint conclusions of the participants in a recently held International Workshop on Ecohydrology and Integrated Water Resource Management (1) at the Navarino Environmental Observatory in Messinia, Greece (2), regarding essential goals for collaborative international efforts in wetland network research. The goals include to investigate on different spatiotemporal scales and in different world regions: a) the dynamics of natural and managed wetland networks across a gradient of different climate, human disturbance, energy and organization conditions; b) the reciprocal interactions between wetland networks and associated hydrological catchments; c) how climate change and different human activities in the wetland network catchments influence these interactions (in b) and generally the ecohydrology of individual wetlands and the whole wetland networks; and d) the ecosystem services provided by networks of wetlands.

  • 28.
    Destouni, Georgia
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Cvetkovic, V.
    Selroos, J.-O.
    Persson, K.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Lagrangian pathway-travel time theory and scenario analysis of tracer-pollutant and uncertainty propagation through catchments2012In: Geophysical Research Abstracts, Vol. 14, EGU2012-6940, 2012, 2012Conference paper (Refereed)
    Abstract [en]

    This paper presents how tracer, nutrient and pollutant transport through a catchment can be analyzed based on mean flow and other flow-transport properties given or resolved by simulations, by following the trajectories (pathways) of transport through the catchment and the flow-transport property distribution among them. Convolution of relevant property distributions across consecutive hydrological units, aggregated over the trajectories that originate from the tracer/pollutant-specific injection area, captures hydrological dispersion with its basic measure derived as the travel time coefficient of variation. Various memory functions can be introduced in a relatively simple manner for incorporating retention/mass transfer mechanisms under conditions of statistical stationarity. The paper further shows how spatial and temporal flow variability can be accounted for in this general theory, and how each and both of these variability components influence hydrological transport in catchments. Moreover, the paper outlines how the theory can be used in a scenario analysis approach to quantify and map the effects of uncertainty in physical and biogeochemical characteristics on diffuse hydrological transport and its uncertainty

  • 29.
    Destouni, Georgia
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Hannerz, Fredrik
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Prieto, Carmen
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Shibuo, Yoshihiro
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Small unmonitored near-coastal catchment areas yielding large mass loading to the sea2008In: Global Biogeochemical Cycles, Vol. 22, no GB4003Article in journal (Refereed)
    Abstract [en]

    Continental freshwater transports and loads excess nutrients and pollutants from various land surface sources into downstream inland and coastal water environments. This study shows that even small, hydrologically unmonitored near-coastal catchment areas may generate large nutrient and pollutant mass loading to the sea of a magnitude similar to or greater than monitored river loads. Systematic near-coastal gaps in the monitoring of freshwater discharges to the sea may therefore mislead the quantification of coastal mass loading significantly. A methodology is presented for quantifying the mass load contributions of all the different unmonitored pathways of hydrological mass transport to the coast, including unmonitored river parts, whole unmonitored streams, and submarine groundwater discharge. This can be used for guiding future efforts to improve monitoring so that it includes the essential hydrological pathways of nutrient and pollutant loading to the sea.

  • 30.
    Destouni, Georgia
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Shibuo, Yoshihiro
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Freshwater flows to the sea: Spatial variability, statistics and scale dependence along coastlines2008In: Geophysical Research Letters, Vol. 35, no L18401Article in journal (Refereed)
    Abstract [en]

    Beyond the monitoring of main river flows, the discharges of freshwater from land to the sea are typically left unmonitored along long coastline stretches. This study uses uniquely fine-resolved data and determines the spatial variability and statistics of the freshwater fluxes to the sea along two Swedish coastlines. The flux statistics depend greatly on subjective investigation choices of the support (or aggregation) scale of flux measurement, H, and the coastline length resolution, G. For common H and G values and relations, the flux coefficient of variation ranges from 1.5 to 22.5 and there is around 90–95% probability that locally measured or modelled fluxes miss the high-end fluxes that are greater than the arithmetic mean flux and carry most of the total freshwater discharge across the coastline. Quantification of the inland hydrological balance and its distribution over the whole coastal catchment area is needed for objective guidance of coastal discharge interpretations.

  • 31.
    Ebert, Karin
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Ekstedt, Karin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    GIS analysis of effects of future Baltic sea level rise on the island of Gotland, Sweden2016In: Natural hazards and earth system sciences, ISSN 1561-8633, E-ISSN 1684-9981, Vol. 16, no 7, p. 1571-1582Article in journal (Refereed)
    Abstract [en]

    Future sea level rise as a consequence of global warming will affect the world's coastal regions. Even though the pace of sea level rise is not clear, the consequences will be severe and global. Commonly the effects of future sea level rise are investigated for relatively vulnerable development countries; however, a whole range of varying regions needs to be considered in order to improve the understanding of global consequences. In this paper we investigate consequences of future sea level rise along the coast of the Baltic Sea island of Gotland, Sweden, with the aim to fill knowledge gaps regarding comparatively well-suited areas in developed countries. We study both the quantity of the loss of features of infrastructure, cultural, and natural value in the case of a 2 m sea level rise of the Baltic Sea and the effects of climate change on seawater intrusion in coastal aquifers, which indirectly cause saltwater intrusion in wells. We conduct a multi-criteria risk analysis by using lidar data on land elevation and GIS-vulnerability mapping, which gives the application of distance and elevation parameters formerly unimaginable precision. We find that in case of a 2 m sea level rise, 3 % of the land area of Gotland, corresponding to 99 km(2), will be inundated. The features most strongly affected are items of touristic or nature value, including camping places, shore meadows, sea stack areas, and endangered plants and species habitats. In total, 231 out of 7354 wells will be directly inundated, and the number of wells in the high-risk zone for saltwater intrusion in wells will increase considerably. Some valuable features will be irreversibly lost due to, for example, inundation of sea stacks and the passing of tipping points for seawater intrusion into coastal aquifers; others might simply be moved further inland, but this requires considerable economic means and prioritization. With nature tourism being one of the main income sources of Gotland, monitoring and planning are required to meet the changes. Seeing Gotland in a global perspective, this island shows that holistic multi-feature studies of future consequences of sea level rise are required to identify overall consequences for individual regions.

  • 32.
    Fischer, Sandra
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Pietroń, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Bring, Arvid
    Stockholm University, Faculty of Science, Department of Physical Geography. University of New Hampshire, USA.
    Thorslund, Josefin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Present to future sediment transport of the Brahmaputra River: reducing uncertainty in predictions and management2017In: Regional Environmental Change, ISSN 1436-3798, E-ISSN 1436-378X, Vol. 17, no 2, p. 515-526Article in journal (Refereed)
    Abstract [en]

    The Brahmaputra River in South Asia carries one of the world's highest sediment loads, and the sediment transport dynamics strongly affect the region's ecology and agriculture. However, present understanding of sediment conditions and dynamics is hindered by limited access to hydrological and geomorphological data, which impacts predictive models needed in management. We here synthesize reported peer-reviewed data relevant to sediment transport and perform a sensitivity analysis to identify sensitive and uncertain parameters, using the one-dimensional model HEC-RAS, considering both present and future climatic conditions. Results showed that there is considerable uncertainty in openly available estimates (260-720 Mt yr(-1)) of the annual sediment load for the Brahmaputra River at its downstream Bahadurabad gauging station (Bangladesh). This may aggravate scientific impact studies of planned power plant and reservoir construction in the region, as well as more general effects of ongoing land use change and climate change. We found that data scarcity on sediment grain size distribution, water discharge, and Manning's roughness coefficient had the strongest controls on the modelled sediment load. However, despite uncertainty in absolute loads, we showed that predicted relative changes, including a future increase in sediment load by about 40 % at Bahadurabad by 2075-2100, were consistent across multiple model simulations. Nevertheless, for the future scenarios we found that parameter uncertainty almost doubled for water discharge and river geometry, highlighting that improved information on these parameters could greatly advance the abilities to predict and manage current and future sediment dynamics in the Brahmaputra river basin.

  • 33. Frolova, Natalia L.
    et al.
    Belyakova, Pelagiya A.
    Grigoriev, Vadim Yu.
    Sazonov, Alexey A.
    Zotov, Leonid V.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Runoff fluctuations in the Selenga River Basin2017In: Regional Environmental Change, ISSN 1436-3798, E-ISSN 1436-378X, Vol. 17, no 7, p. 1965-1976Article in journal (Refereed)
    Abstract [en]

    The Selenga River has historically provided 50% of the total freshwater water input to the Lake Baikal, transporting substances and pollutants that can considerably impact the unique lake ecosystem. In the context of on-going regional to global change, we here aim at identifying and understanding mechanisms behind spatial and temporal variability and trends in the flow of the Selenga River and its tributaries, based on hydrological and meteorological station data (since the 1930s), remote sensing, and statistical analyses. Results show that the flow of the Selenga River exhibits cycles with phases of high flows lasting 12 to 17 years and phases of low flows that historically lasted for about 7 years. However, despite an asynchronous behavior between right-bank tributaries and left-bank tributaries, the flow of the Selenga River near its delta at Lake Baikal has now been low (30% below the 1934-1975 average) for as long as 20 years, due to reduced input from precipitation, particularly during the summer season. Observed decreases in annual maximum hourly flows and decreases in annual minimum 30-day flows are consistent with increasing activation of the groundwater system due to thawing permafrost, and higher winter temperatures that support increased winter flows by preventing rivers to freeze from top to bottom. These recent and relatively large changes have implications for regional water planning and management, including the planned large-scale hydropower expansion in the upper part of the Selenga River Basin.

  • 34.
    Jarsjö, J.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Frampton, A.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Cvetkovic, V.
    Destouni, G.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Scenario analysis of CO2 injection into a multilayered saline aquifer system of Scania, Sweden2011In: Geophysical Research Abstracts, Vol. 13, EGU2011-8316, 2011Conference paper (Refereed)
  • 35.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Agricultural pollution impacts on health and environment in the Aral Sea Basin2007In: NATO ARW: Environmental Problems of Central Asia and Their Economic, Social and Security Impacts, 2007Conference paper (Other academic)
  • 36.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Geological storage of CO2 in deep aquifers: Open research questions on how to minimize return flows to the atmosphere2009In: International Conference on Applied Energy (ICAE09): January 5 - 7, 2009, Hong Kong, 2009, p. 1313-1322Conference paper (Refereed)
    Abstract [en]

    Deep aquifer storage of CO2 captured from point sources, such as power plants, is a technologically mature and economically feasible CO2 storage option. A main challenge is however to find geological settings and storage designs that can keep the captured CO2 isolated from the atmosphere for sufficiently long time to mitigate climate change. At many sites, unwanted CO2 return flows could occur preferentially through rock fractures. Current numerical models are however based on constitutive relations that were developed and verified for mixed gas – water flows in soil. Their parameters cannot be independently measured in rock fractures. We here consider geophysical data from 20 different rock fractures, and show that although predictive modelling of gas-water flows through fractures should be based on a different parameterisation than modelling of gas-water flows through soil, the underlying characteristic shapes of soil drainage curves can be matched to fracture-based characteristic relations. This means that gas-water flows through soil and fractured rock in many cases share similar, basic gas-water flow behaviours. Through a proposed curve-matching procedure, site-specific fracture aperture-based parameters can be translated into a set of soil parameters that are accepted by current numerical models, which then can be directly used for predicting e.g. CO2 flows through fractured rock environments. However, parallel research has shown that gas bubble immobilisation through capillary trapping mechanisms, and flow channelling, can in some cases be considerable and may need to be accounted for in predictions of CO2 return-flows from geological storage sites.

  • 37.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Asokan, Shilpa M.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Prieto, Carmen
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Bring, Arvid
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Hydrological responses to climate change conditioned by historic alterations of land use and water use2012In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 16, no 5, p. 1335-1347Article in journal (Refereed)
    Abstract [en]

    This paper quantifies and conditions expected hydrological responses in the Aral Sea Drainage Basin (ASDB; occupying 1.3% of the earth's land surface), Central Asia, to multi-model projections of climate change in the region from 20 general circulation models (GCMs). The aim is to investigate how uncertainties of future climate change interact with the effects of historic human re-distributions of water for land irrigation to influence future water fluxes and water resources. So far, historic irrigation changes have greatly amplified water losses by evapotranspiration (ET) in the ASDB, whereas 20th century climate change has not much affected the regional net water loss to the atmosphere. Results show that errors in temperature (T) and precipitation (P) from single GCMs have large influence on projected change trends (for the period 2010-2039) of river runoff (R), even though the ASDB is spatially well resolved by current GCMs. By contrast, observed biases in GCM ensemble mean results have relatively small influence on projected R change trends. Ensemble mean results show that projected future climate change will considerably increase the net water loss to the atmosphere. Furthermore, the ET response strength to any future T change will be further increased by maintained (or increased) irrigation practices, which shows how climate change and water use change can interact in modifying ET (and R). With maintained irrigation practices, R is likely to decrease to near-total depletion, with risk for cascading ecological regime shifts in aquatic ecosystems downstream of irrigated land areas. Without irrigation, the agricultural areas of the principal Syr Darya river basin could sustain a 50% higher T increase (of 2.3 A degrees C instead of the projected 1.5 A degrees C until 2010-2039) before yielding the same consumptive ET increase and associated R decrease as with the present irrigation practices.

  • 38.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Asokan, Shilpa M
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Shibuo, Yoshihiro
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Water scarcity in the Aral sea drainage basin: Contributions of agricultural irrigation and a changing climate2008In: Environmental Problems of Central Asia and Their Economic, Social and Security Impacts, 2008, p. 99-108Conference paper (Refereed)
    Abstract [en]

    Changed ambient conditions in the Aral Sea Drainage Basin (ASDB) in Central Asia have led to drastically decreased river discharges into the Aral Sea during the twentieth century. This decrease has in turn led to the still ongoing Aral Sea desiccation and to particularly adverse environmental effects, in terms of both affected number of people and degree of environmental degradation in the ASDB. We have used a distributed basin-scale hydrological balance modeling approach for estimating the relative influences of agricultural irrigation and climate change, respectively, on observed decreases of river discharges in the ASDB. Results show that water losses through evapotranspiration increased as a result of higher temperatures in the basin after 1950. However, these increases in evapotranspiration loss due to rising temperatures alone are smaller than the water gains caused by increased precipitation in the ASDB over the same time period. Climatic changes can therefore not at all have contributed to the observed drying of the rivers in the basin, at least not so far. By contrast, the evapotranspiration loss increases from the expanded agricultural irrigation in the area can fully explain the decreased river discharges and the present water scarcity in the ASDB. We further show that the largest increase (1.85 oC) in seasonal average temperature in the basin has occurred in the winter, whereas the smallest increase (0.69 oC) has occurred in the summer. This result is consistent with a surface temperature cooling effect of intense irrigation in the summer, which should have increased since the 1950’s due to the evapotranspiration increase implied by the major irrigation expansion in the ASDB.

  • 39.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Asokan, Shilpa Muliyil
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Shibuo, Yoshihiro
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Water scarcity in the Aral Sea Drainage Basin: Contributions of agricultural irrigation and a changing climate2008In: Environmental Problems of Central Asia and their Economic, Social and Security Impacts. Book Series: Nato Science for Peace and Security Series C: Environmental Security; Qi J, Evered KT (Eds.), ISSN 1874-6519, p. 99-108Article in journal (Refereed)
  • 40.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Bayer-Raich, Martí
    Estimating plume degradation rates in aquifers: Effect of propagating measurement and methodological errors2008In: Water Resources Research, Vol. 44, p. W02501-Article in journal (Refereed)
    Abstract [en]

    Field estimates of plume degradation rates lambda [T–1] in aquifers provide a basis for assessing the possible impact of (toxic) organic pollutants on downstream environments; however, difficulties with measurement and methodology mean that estimated site-specific rates potentially involve considerable uncertainty. Here, we specifically show that if mass flow or average concentration measurements are associated with errors of ~20% (or even less), the errors may in many cases propagate, magnify, and cause order-of-magnitude errors in estimates of lambda. We also investigate uncertainties in the integral pumping test method, in which average concentrations are determined based on concentrations measured from pumping wells. In this method, the small-scale variability that may bias the results of point measurements can be favourably averaged out when pumping; however, the novelty of the approach means that questions remain regarding its application. For example, the magnitude of methodological errors, such as those associated with the assumption of constant concentration along the flow direction within the extent of the well capture zone, remain poorly understood. This assumption can be violated by the biodegradation of contaminants, thereby leading to a bias in subsequent interpretations. We provide an analytical expression from which the prediction error due to attenuating concentrations can be evaluated, and show its dependence on the degradation rate, the degradation function, and the extent of the well capture zone. Even for considerable first-order degradation rates, the error generally remains small and is not magnified in estimates of lambda.

  • 41.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Chalov, Sergey R.
    Pietron, Jan
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Alekseenko, Alexey V.
    Thorslund, Josefin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Patterns of soil contamination, erosion and river loading of metals in a gold mining region of northern Mongolia2017In: Regional Environmental Change, ISSN 1436-3798, E-ISSN 1436-378X, Vol. 17, no 7, p. 1991-2005Article in journal (Refereed)
    Abstract [en]

    Mining has become one of the main causes of increased heavy metal loading of river systems throughout the world. There is however an evident gap between assessments of soil contamination and metal release at the mined sites and estimates of river pollution. The present work focuses on Zaamar Goldfield, which is one of the largest placer gold mines in the world, located along the Tuul River, Mongolia, which ultimately drains into Lake Baikal, Russia. It combines field observations in the river basin with soil erosion modelling and aims at quantifying the contribution from natural erosion of metal-rich soil to observed increases in mass flows of metals along the Tuul River. Results show that the sediment delivery from the mining area to the Tuul River is considerably higher than the possible contribution from natural soil erosion. This is primarily due to excessive mining-related water use creating turbid wastewaters, disturbed filtering functions of deposition areas (natural sediment traps) close to the river and disturbances from infrastructures such as roads. Furthermore, relative to background levels, soils within Zaamar Goldfield contained elevated concentrations of As, Sr, Mn, V, Ni, Cu and Cr. The enhanced soil loss caused by mining-related activities can also explain observed, considerable increases in mass flows of metals in the Tuul River. The present example from Tuul River may provide useful new insights regarding the erosion and geomorphic evolution of mined areas, as well as the associated delivery of metals into stream networks.

  • 42.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Persson, Klas
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Prieto, Carmen
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Solute transport in coupled inland – coastal water systems: General conceptualisation and application to Forsmark2008Report (Other academic)
    Abstract [en]

    We formulate a general theoretical conceptualisation of solute transport from inland sources to downstream recipients, considering main recipient load contributions from all different nutrient and pollutant sources that may exist within any catchment. Since the conceptualisation is model-independent, its main hydrological factors and mass delivery factors can be quantified on the basis of inputs to and outputs from any considered analytical or numerical model. Some of the conceptually considered source contribution and transport pathway combinations are however commonly neglected in catchment-scale solute transport and attenuation modelling, in particular those related to subsurface sources, diffuse sources at the land surface and direct groundwater transport into the recipient. The conceptual framework provides a possible tool for clarification of underlying and often implicit model assumptions, which can be useful for e.g. inter-model comparisons in SKB’s site investigation or safety assessment programmes.

    In order to further clarify and explain research questions that may be of particular importance for transport pathways from deep groundwater surrounding a repository, we concretise and interpret some selected transport scenarios for model conditions in the Forsmark area. Possible uncertainties in coastal discharge predictions (that underpin all transport results), related to uncertain spatial variation of evapotranspiration within the catchment, were shown to be small for the relatively large, focused surface water discharges from land to sea, because local differences were averaged out along the length of the main water flow paths. In contrast, local flux values within the diffuse groundwater flow field from land to sea are more uncertain, although estimates of mean values and total sums of submarine groundwater discharge (SGD) along some considerable coastline length may be robust. The present results show that 80% to 90% of the total coastal discharge of Forsmark occurred through focused flows in visible streams, whereas the remaining 10% to 20% was diffuse and occurring through submarine groundwater discharge (SGD), small transient streams and/ or coastal wetlands.

    Regarding transport quantifications, hydrogeochemical characteristics and pollution source loads may generally differ between larger, monitored catchments and smaller unmonitored coastal catchments. Since national hydrological monitoring data systematically exclude smaller, coastal catchments, they may not be representative for conditions in Forsmark (or Simpevarp). This emphasises the importance of extending in time the recently started hydrological and hydrogeochemical data series in the Forsmark and Simpevarp coastal catchment areas, since they are in effect unmonitored from a hydrological viewpoint, due to the lack of extended discharge time series.

    In the performed initial demonstration analysis of solute transport pathways from deep groundwater to recipients at the surface, we considered the main scenarios: (I) transport in the quaternary deposits/bedrock interface zone only (assuming that the deep groundwater transport pathway to the coast excludes the inland surface water system), and (II) transport in the coupled groundwater-surface water system. Considering mean travel times from each model cell to the coast, and disregarding travel times in the deep bedrock domain itself (which may be added to the here presented values), results show that travel times in scenario (II) were less than 4 years in 90% of the considered model area (i.e., the Forsmark catchment area). Travel times were longer in scenario (I) with values higher than 10 years in 40% of the catchment area. These results are based on the assumption that the pathways do not go through zones of near-stagnant groundwater (found e.g. below Lake Bolundsfjärden, Lake Eckarfjärden and Lake Gällsboträsket in Forsmark). If they would do so (and the above assumption is violated), results show that travel times can be considerably longer, for instance exceeding 400 years in half of the model area in scenario (I).

    Considering possible solute attenuation (caused by e.g. biogeochemical reactions or decay) along the hydrological transport pathways to inland surface waters and to the coast, we estimate solute mass delivery factors, representing the fraction of mass released in a cell that reaches the considered recipient. Results showed that average delivery factors, representing the whole catchment and equalling expected delivery factors in the probabilistic case, can exhibit considerable differences between transport pathway scenarios (I) and (II). However, the magnitude of the differences in average delivery factors (between transport pathway scenarios as well as between considered release points) depends on the actual attenuation rates (i.e., l-values). This is because for low l (for Forsmark: l<0.01 year-1), practically all mass reaches the coast regardless of release point and scenario, and for high l (for Forsmark: l>10 year-1) only a small fraction of the mass reaches the coast regardless of release point and scenario.

    The above results imply that, in general, mass delivery factors to recipients are sensitive to both pathways and entrance points or areas in the quaternary deposits of Forsmark, with for instance a remaining key question being to which extent the deep groundwater transport pathway to the coast includes the surface water system and /or quaternary deposits/bedrock interface zone. However, given more specific sub-catchment areas (e.g., of biosphere objects of interest) and possible ranges of attenuation rates (of compounds of interest) from parallel studies, the present analyses also show that robust predictions regarding e.g. mass delivery can in some cases be obtained despite considerable pathway and entrance point uncertainties. Because such cases then can be excluded from further investigation, it appears that specific transport analyses that considers relevant combinations of possible release points, transport pathway scenarios and attenuation rates can be used for delimiting specific priority regions, where remaining uncertainties are high and further experimental investigations and/or monitoring hence may be needed to reduce the uncertainties.

  • 43.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Shibuo, Yoshihiro
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Neurochemistry.
    Spatial distribution of unmonitored inland water discharges to the sea2007In: Eos Trans. (2007) AGU, 88(52), Fall Meet. Suppl.: Abstract H43E-1675, 2007Conference paper (Other academic)
    Abstract [en]

    Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract H43E-1675, 2007

  • 44.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Shibuo, Yoshihiro
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Spatial distribution of unmonitored inland water discharges to the sea2008In: Journal of Hydrology, Vol. 348, p. 59-72Article in journal (Refereed)
    Abstract [en]

    We develop a modelling methodology and investigate how spatial data on catchment surface characteristics may be used for quantifying relative coastal discharge contributions of streams and diffuse submarine groundwater discharge along the coastlines of unmonitored near-coastal catchment areas. The methodology is applied to two small Swedish coastal catchments areas, considering also two different ways to estimate evapotranspiration and its spatial variation within the catchments. Despite considerable differences between the characteristics of the two catchment areas, their relative coastal distribution results are similar, with about 80% of the total coastal discharge occurring through focused flows in visible and permanent streams, whereas the remaining 20% is diffuse and may occur through submarine groundwater discharge (SGD), small transient streams or both at different points in time. Evapotranspiration differs between the two used models, which results in relatively uncertain local flux values within the diffuse flow fields. The large focused stream flows and the mean values and total sums of diffuse flows (such as SGD) along some considerable coastline length, however, are constrained by the catchment-scale hydrological balance and considerably more robust and certain to estimate than the spatially variable small local fluxes within the diffuse flow fields.

  • 45.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Törnqvist, Rebecka
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Su, Ye
    Climate-driven change of nitrogen retention-attenuation near irrigated fields: multi-model projections for Central Asia2017In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 76, no 3, article id 117Article in journal (Refereed)
    Abstract [en]

    Agricultural intensification in semiarid regions comes at a cost of relatively high water losses through evapotranspiration and can contribute to releases of nutrients and pesticides that affect downstream water quality. In addition, highly managed river basins may be particularly sensitive to future climate change. However, effects on retention-attenuation of nutrients are difficult to quantify due to the complexity and variability of relevant processes. We here use the example case of the large (covering 1.3% of the earth's land surface) and extensively irrigated Aral Sea Drainage Basin (ASDB) in Central Asia, together with 73 general circulation model (GCM) projection results and field-data driven nitrogen retention-attenuation modeling, to investigate to which extent projected future climate change (for years 2025, 2050 and 2100) can influence nitrogen loads and concentrations in the water systems of the basin. Results for the principal Amu Darya River of the ASDB suggest that riverine concentrations of nitrogen will decrease considerably throughout the coming century. This is due to projected climate-related decreases in runoff and river discharge, which increases internal nitrogen recirculation ratios, average transport distances and nitrogen retention-attenuation. However, in groundwater near the agricultural fields, there is in contrast a risk of considerable nitrogen accumulation. More generally, the sensitivity of nitrogen concentrations in the ADRB to climate-driven changes in runoff and discharge is likely to be shared with many highly managed basins in arid and semiarid regions of Central Asia, and the world.

  • 46.
    Jarsjö, Jerker
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Törnqvist, Rebecka
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Ye, Su
    Department of Physical Geography and Geoecology, Charles University in Prague.
    Climate-driven change in circulation of nitrogen and irrigation water: Multi-model projections for Central AsiaManuscript (preprint) (Other academic)
    Abstract [en]

    Agricultural intensification in semi-arid regions comes at a cost of relatively high water losses through evapotranspiration and can contribute to releases of nutrients and pesticides that affect downstream water quality. In addition, highly managed river basins may be particularly sensitive to future climate change. However, effects on attenuation and transformation of nutrients are difficult to quantify due to the complexity and variability of relevant processes. We here use the example case of the large (covering 1.3% of the earth’s land surface) and extensively irrigated Aral Sea Drainage Basin (ASDB) in Central Asia, together with 65 GCM projection results and field-data driven nitrogen attenuation modeling, to investigate to which extent projected future climate change (for years 2025, 2050 and 2100) can influence nitrogen cycling and attenuation. Results show that water and nitrogen circulation are sensitive to climate-driven changes in discharge of the principal Amu Darya River in the ASDB. This is likely the case also for other highly managed river basins across the world. Specifically, we show that riverine concentrations of nitrogen may decrease considerably throughout the coming century. This is due to projected climate-related decreases in river flow at the basin outlet, which increases internal nitrogen recirculation ratios, average transport distances, and attenuation.

  • 47.
    Koutsouris, A. J.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Destouni, Georgia
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Lyon, Steve W.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Hydro-climatic trends and water resource management implications based on multi-scale data for the Lake Victoria region, Kenya2010In: Environmental Research Letters, ISSN 1748-9326, E-ISSN 1748-9326, Vol. 5, no 3, p. 034005-Article in journal (Refereed)
    Abstract [en]

    Unreliable rainfall may be a main cause of poverty in rural areas, such as the Kisumu district byLake Victoria in Kenya. Climate change may further increase the negative effects of rainfalluncertainty. These effects could be mitigated to some extent through improved and adaptive water resource management and planning, which relies on our interpretations and projections of the coupled hydro-climatic system behaviour and its development trends. In order to identify and quantify the main differences and consistencies among such hydro-climatic assessments, this study investigates trends and exemplifies their use for important water management decisions for the Lake Victoria drainage basin (LVDB), based on local scale data for the Orongovillage in the Kisumu district, and regional scale data for the whole LVDB. Results show low correlation between locally and regionally observed hydro-climatic trends, and large differences, which in turn affects assessments of important water resource management parameters. However, both data scales converge in indicating that observed local and regional hydrological discharge trends are primarily driven by local and regional water use and land use changes.

  • 48. Lychagin, M.
    et al.
    Chalov, S.
    Kasimov, N.
    Shinkareva, G.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Thorslund, Josefin
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Surface water pathways and fluxes of metals under changing environmental conditions and human interventions in the Selenga River system2017In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 76, no 1, article id 1Article in journal (Refereed)
    Abstract [en]

    This paper presents the results of novel field campaigns in the extensive (447,000 km(2)) Selenga River basin, through which 304 samples of river water and 308 samples of suspended matter were collected during high and low water periods between 2011 and 2013. The Selenga River is the largest tributary (more than 50% of the inflow) to the Lake Baikal. Due to ongoing hydroclimatic change and human pressures under conditions of economic growth, the rivers of the area experience significant change in water quality. A key issue for improved understanding of regional impacts of the environmental change is to disentangle the influence of climate change from that of other pressures within the catchment. Our research aims to evaluate the pathways and mass flows of heavy metals and metalloids both in dissolved and suspended forms, taking a basin- scale perspective that previously has not been fully pursued in the Lake Baikal region. Results showed quality deterioration over short distances due to strong impact of hot spots from urban and industrial activities, including mining. The determined enrichment of dissolved metals in waters of Selenga River as well as the spatial and temporal variability of water and suspended sediment composition is further analyzed in the context of climatic, hydrological and land use drivers.

  • 49.
    Lyon, Steve W.
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Koutsouris, Alexander
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Scheibler, Friedemann
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Mbanguka, Rene
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Tumbo, Madaka
    Robert, Keven K.
    Sharma, Asha N.
    van der Velde, Ype
    Interpreting characteristic drainage timescale variability across Kilombero Valley, Tanzania2015In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 29, no 8, p. 1912-1924Article in journal (Refereed)
    Abstract [en]

    We explore seasonal variability and spatiotemporal patterns in characteristic drainage timescale (K) estimated from river discharge records across the Kilombero Valley in central Tanzania. K values were determined using streamflow recession analysis with a Brutsaert-Nieber solution to the linearized Boussinesq equation. Estimated K values were variable, comparing between wet and dry seasons for the relatively small catchments draining upland positions. For the larger catchments draining through valley bottoms, K values were typically longer and more consistent across seasons. Variations in K were compared with long-term averaged, Moderate-resolution Imaging Spectroradiometer-derived monthly evapotranspiration. Although the variations in K were potentially related to evapotranspiration, the influence of data quality and analysis procedure could not be discounted. As such, even though recession analysis offers a potential approach to explore aquifer release timescales and thereby gain insight to a region's hydrology to inform water resources management, care must be taken when interpreting spatiotemporal shifts in K in connection with process representation in regions like the Kilombero Valley.

  • 50. Malmström, Maria E.
    et al.
    Berglund, Sten
    Jarsjö, Jerker
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Combined effects of spatially variable flow and mineralogy on the attenuation of acid mine drainage in groundwater2008In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 23, no 6, p. 1419-1436Article in journal (Refereed)
    Abstract [en]

    Quantifications of the spreading of acid mine drainage (AMD) in groundwater are needed for risk assessments of mining sites. However, due to subsurface heterogeneity, available field data may prove insufficient for deterministic process descriptions, even at well-characterized sites. Here, the probabilistic LaSAR-PHREEQC model is used to consider multicomponent reactions and transport in heterogeneous (flow and geochemistry) groundwater surrounding a mine waste site, with specific focus on the spreading of Zn. Model results, using field data from a mill tailings impoundment in northern Sweden (including major component geochemistry), indicate that precipitation of smithsonite (ZnCO3) may drastically delay the downstream arrival of Zn, but may also cause a peak concentration once the retained Zn is released. The amount of smithsonite formed is, however, minute and its spatial variation large, such that detection of smithsonite in soil samples may be difficult. Results further show that even a low degree of flow heterogeneity can effectively smooth otherwise distinctive temporal concentration changes attributed to the considered chemical reactions, and thereby mask the attenuation processes. By contrast, the existence of preferential flow paths can cause temporally separated concentration peaks in response to a single chemical reaction chain, even in a geochemically homogeneous domain, making the interpretation of the concentration curves non-trivial. The stochastic modelling results for Zn considering flow and/or mineralogical heterogeneity indicate a less efficient Zn attenuation than predicted by standard, deterministic reactive-transport models. In addition, in all considered probabilistic Zn and SO4(2-) scenarios, the spatial variability in downstream pollutant concentration was high, implying that a relatively large number of point samples are needed to determine field-scale mean concentrations.

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