Groundwater seepage controls salinity in a hydrologically terminal basin of semi-arid northwest Australia

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    Abstract

    © 2016 Elsevier B.V.
    Very small groundwater outflows have the potential to significantly impact the hydrochemistry and salt accumulation processes of notionally terminal basins in arid environments. However, this limited groundwater outflow can be very difficult to quantify using classical water budget calculations due to large uncertainties in estimates of evaporation and evapotranspiration rates from the surface of dry lake beds. In this study, we used a dimensionless time evaporation model to estimate the range of groundwater outflow required to maintain salinity levels observed at the Fortescue Marsh (FM), one of the largest wetlands of semi-arid northwest Australia (~1100 km2). The groundwater outflow from aquifers underlying the FM to the Lower Fortescue catchment is constrained by an extremely low hydraulic gradient of 300 g/L) after ~45 ka. We calculated that only a very small seepage of ~2G L/yr (~0.03% of the FM water volume) is sufficient to maintain current salinity conditions. The minimum time required to develop the current hydrochemical groundwater composition under the FM ranges from ~60 to ~165 ka. We conclude that a dimensionless time evaporation model versus inflow over outflow ratio model is likely more suitable than classical water budget calculations for determining outflow from large saline lakes and to estimate groundwater seepage from hydrologically terminal basins.
    Original languageEnglish
    Pages (from-to)627-636
    JournalJournal of Hydrology
    Volume542
    Early online date14 Sep 2016
    DOIs
    Publication statusPublished - Nov 2016

    Fingerprint

    seepage
    outflow
    salinity
    groundwater
    marsh
    basin
    evaporation
    water budget
    hydrochemistry
    saline lake
    arid environment
    evapotranspiration
    inflow
    wetland
    aquifer
    catchment
    salt
    hydraulics
    lake
    water

    Cite this

    @article{a3069a185dda45fcb3e7f0d34bd065ee,
    title = "Groundwater seepage controls salinity in a hydrologically terminal basin of semi-arid northwest Australia",
    abstract = "{\circledC} 2016 Elsevier B.V.Very small groundwater outflows have the potential to significantly impact the hydrochemistry and salt accumulation processes of notionally terminal basins in arid environments. However, this limited groundwater outflow can be very difficult to quantify using classical water budget calculations due to large uncertainties in estimates of evaporation and evapotranspiration rates from the surface of dry lake beds. In this study, we used a dimensionless time evaporation model to estimate the range of groundwater outflow required to maintain salinity levels observed at the Fortescue Marsh (FM), one of the largest wetlands of semi-arid northwest Australia (~1100 km2). The groundwater outflow from aquifers underlying the FM to the Lower Fortescue catchment is constrained by an extremely low hydraulic gradient of 300 g/L) after ~45 ka. We calculated that only a very small seepage of ~2G L/yr (~0.03{\%} of the FM water volume) is sufficient to maintain current salinity conditions. The minimum time required to develop the current hydrochemical groundwater composition under the FM ranges from ~60 to ~165 ka. We conclude that a dimensionless time evaporation model versus inflow over outflow ratio model is likely more suitable than classical water budget calculations for determining outflow from large saline lakes and to estimate groundwater seepage from hydrologically terminal basins.",
    author = "Grzegorz Skrzypek and Shawan Dogramaci and Alexandra Rouillard and Grierson, {Pauline F.}",
    year = "2016",
    month = "11",
    doi = "10.1016/j.jhydrol.2016.09.033",
    language = "English",
    volume = "542",
    pages = "627--636",
    journal = "Journal of Hydrology",
    issn = "0022-1694",
    publisher = "Pergamon",

    }

    TY - JOUR

    T1 - Groundwater seepage controls salinity in a hydrologically terminal basin of semi-arid northwest Australia

    AU - Skrzypek, Grzegorz

    AU - Dogramaci, Shawan

    AU - Rouillard, Alexandra

    AU - Grierson, Pauline F.

    PY - 2016/11

    Y1 - 2016/11

    N2 - © 2016 Elsevier B.V.Very small groundwater outflows have the potential to significantly impact the hydrochemistry and salt accumulation processes of notionally terminal basins in arid environments. However, this limited groundwater outflow can be very difficult to quantify using classical water budget calculations due to large uncertainties in estimates of evaporation and evapotranspiration rates from the surface of dry lake beds. In this study, we used a dimensionless time evaporation model to estimate the range of groundwater outflow required to maintain salinity levels observed at the Fortescue Marsh (FM), one of the largest wetlands of semi-arid northwest Australia (~1100 km2). The groundwater outflow from aquifers underlying the FM to the Lower Fortescue catchment is constrained by an extremely low hydraulic gradient of 300 g/L) after ~45 ka. We calculated that only a very small seepage of ~2G L/yr (~0.03% of the FM water volume) is sufficient to maintain current salinity conditions. The minimum time required to develop the current hydrochemical groundwater composition under the FM ranges from ~60 to ~165 ka. We conclude that a dimensionless time evaporation model versus inflow over outflow ratio model is likely more suitable than classical water budget calculations for determining outflow from large saline lakes and to estimate groundwater seepage from hydrologically terminal basins.

    AB - © 2016 Elsevier B.V.Very small groundwater outflows have the potential to significantly impact the hydrochemistry and salt accumulation processes of notionally terminal basins in arid environments. However, this limited groundwater outflow can be very difficult to quantify using classical water budget calculations due to large uncertainties in estimates of evaporation and evapotranspiration rates from the surface of dry lake beds. In this study, we used a dimensionless time evaporation model to estimate the range of groundwater outflow required to maintain salinity levels observed at the Fortescue Marsh (FM), one of the largest wetlands of semi-arid northwest Australia (~1100 km2). The groundwater outflow from aquifers underlying the FM to the Lower Fortescue catchment is constrained by an extremely low hydraulic gradient of 300 g/L) after ~45 ka. We calculated that only a very small seepage of ~2G L/yr (~0.03% of the FM water volume) is sufficient to maintain current salinity conditions. The minimum time required to develop the current hydrochemical groundwater composition under the FM ranges from ~60 to ~165 ka. We conclude that a dimensionless time evaporation model versus inflow over outflow ratio model is likely more suitable than classical water budget calculations for determining outflow from large saline lakes and to estimate groundwater seepage from hydrologically terminal basins.

    U2 - 10.1016/j.jhydrol.2016.09.033

    DO - 10.1016/j.jhydrol.2016.09.033

    M3 - Article

    VL - 542

    SP - 627

    EP - 636

    JO - Journal of Hydrology

    JF - Journal of Hydrology

    SN - 0022-1694

    ER -