Sökning: "naturgeografi"

Visar resultat 1 - 5 av 107 avhandlingar innehållade ordet naturgeografi.

  1. 1. Regulation of carbon dioxide emission from Swedish boreal lakes and the Gulf of Bothnia

    Detta är en avhandling från Umeå universitet

    Författare :Grete Algesten; Mats Jansson; Pirkko Kortelainen; [2005]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography and sedimentology; lakes; boreal; Gulf of bothnia; CO2; NEE; DOC; mineralization; sediment; catchment; net heterotrophy; Naturgeografi och sedimentologi; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; naturgeografi; Physical Geography;

    Sammanfattning : The global carbon cycle is subject to intense research, where sources and sinks for greenhouse gases, carbon dioxide in particular, are estimated for various systems and biomes. Lakes have previously been neglected in carbon balance estimations, but have recently been recognized to be significant net sources of CO2. LÄS MER

  2. 2. Diatoms as indicators of Holocene climate and environmental change in northern Sweden

    Detta är en avhandling från Umeå : Ekologi och geovetenskap

    Författare :Christian Bigler; Ingemar Renberg; Roland Hall; N. John Anderson; [2001]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography and sedimentology; diatoms; Holocene; paleolimnology; climate change; lake sediments; transfer functions; quantitative environmental reconstructions; northern Sweden; Abisko; Naturgeografi och sedimentologi; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; naturgeografi; Physical Geography;

    Sammanfattning : The objective of the thesis was to explore the potential of diatoms (Bacillariophyceae) as indicators of Holocene climate and environmental change in northern Sweden (Abisko region, 68°21'N, 18°49'E). A modern surface-sediment calibration set including 100 lakes was developed and lake-water pH, sedimentary organic content (assessed by loss-on-ignition) and temperature were identified as most powerful environmental variables explaining the variance within the diatom assemblages. LÄS MER

  3. 3. Lake sediments around the Antarctic Peninsula archives of climatic and environmental changes

    Detta är en avhandling från Umeå : Ekologi och geovetenskap

    Författare :Rolf Zale; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake sediments; Antarctic Peninsula; radiocarbon dating; climatic and environmental changes; sediment chemistry; naturgeografi; Physical Geography;

    Sammanfattning : Lakes and lake sediments from four areas around the Antarctic Peninsula are described.The concentrations of trace metals in sediment are found to be a useful tool in distinguishing between the different sedimentary phases during a transition from marine to limnic environment. LÄS MER

  4. 4. Response of glaciers to climate change : Mass balance sensitivity, sea level rise and runoff

    Detta är en avhandling från Stockholm : Institutionen för naturgeografi och kvartärgeologi

    Författare :Mattias de Woul; Regine Hock; Peter Jansson; Margareta Hansson; Roger J. Braithwaite; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; glacier; mass balance modelling; mass balance sensitivity; sea level rise; glacial runoff; Hofsjökull; Storglaciären; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; Physical Geography; naturgeografi;

    Sammanfattning : The purpose of this study is to enhance our understanding of the response of glaciers to climate change. Global sea level is affected by changes in glacier ice volume, and melt-water from glaciers is a principal water source in many regions. LÄS MER

  5. 5. Making water information relevant on local to global scale – the role of Information Systems for Integrated Water Management

    Detta är en avhandling från Stockholm : Institutionen för naturgeografi och kvartärgeologi

    Författare :Fredrik Hannerz; Georgia Destouni; Dennis Lettenmaier; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Integrated water management; hydrology; environmental information systems; environmental monitoring; land cover; GIS; Sweden; Baltic Sea; European Union; global water; global change; Water Framework Directive; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; Physical Geography; naturgeografi;

    Sammanfattning : Relevant information is essential for finding solutions in Integrated Water Management (IWM). Complex water systems and a need for increasing integration of sectors, actors and scales in IWM require new methods for developing and managing such information. LÄS MER