Avancerad sökning

Visar resultat 1 - 5 av 22 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Landscape hydrogeochemistry of Fe, Mn, S and trace elements (As, Co, Pb) in a boreal stream network

    Författare :Louise Björkvald; Carl-Magnus Mörth; Hjalmar Laudon; Christine Alewell; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; landscape hydrogeochemistry; boreal streams; spring flood; Fe; Mn; S; As; Co; Pb; sulphur isotopes; sulphate; organic S; DOC; spatial variability; temporal variability; wetlands; Earth sciences; Geovetenskap; geokemi; Geochemistry;

    Sammanfattning : The transport of elements by streams from headwater regions to the sea is influenced by landscape characteristics. This thesis focuses on the influence of landscape characteristics (e.g. LÄS MER

  3. 2. Hydrological Seasonal Forecasting

    Författare :Kean Foster; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hydrological seasonal forecasting; seasonal forecast; spring flood; multi-model ensembles; teleconnection patterns; modelling chain;

    Sammanfattning : In Sweden, almost half of the electricity produced comes from hydropower. However, the amount of water in the reservoir catchments is not evenly distributed throughout the year. During the colder months, precipitation usually falls as snow and accumulates into a snowpack. LÄS MER

  4. 3. Lateral movements versus stationarity : adaptive alternatives in benthic invertebrates to the seasonal environment in a boreal river

    Författare :Tommy I. Olsson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Benthic invertebrates; cold-hardiness; ice; migrations; overwintering; river; seasonal variations; spatial distribution; spring flood; water level;

    Sammanfattning : Benthic invertebrates inhabiting boreal rivers are exposed to very large seasonal variations in their physical environment. The extremes are in winter when the littoral area freezes solid and in spring when water flow increases rapidly. LÄS MER

  5. 4. Hydrogeochemistry of Fe and Mn in small boreal catchments

    Författare :Louise Björkvald; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hydrogeochemistry; Fe; Mn; boreal catchments; spring flood; Other earth sciences; Övrig geovetenskap;

    Sammanfattning : It is suggested that the overall understanding of the general hydrogeochemistry of a region is best understood from a landscape perspective. If so, this can provide useful information when planning monitoring programmes and influence of human activity. LÄS MER

  7. 5. Utilization of terrestrially derived dissolved organic nitrogen by aquatic bacteria

    Författare :Ramunas Stepanauskas; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; amino acids; spring flood; UV radiation; estuarine mixing; microbial loop; bacterial bioassays; marine eutrophication; bioavailability; Dissolved organic nitrogen; DON; extracellular aminopeptidase; Baltic Sea; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Sammanfattning : I investigated the bacterial utilization of terrestrially derived dissolved organic nitrogen (DON) in aquatic ecosystems, and assessed the potential role of river-born DON in marine eutrophication. To determine the bioavailability of DON, I developed a bioassay employing N-limited bacterial regrowth cultures, which were calibrated with additions of inorganic nitrogen. LÄS MER