Sökning: "lake-level changes"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden lake-level changes.

  1. 1. Past environmental and climate changes in northern Tanzania : Vegetation and lake level variability in Empakaai Crater

    Författare :Maria Ryner; Karin Holmgren; Peter Kuhry; Lars-Ove Westerberg; Henry Lamb; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; palaeoecology; palaeolimnology; physical and societal factors; Holocene; Tanzania; Lake Emakat; Engaruka; Earth sciences; Geovetenskap; Physical Geography; geografi med naturgeografisk inriktning;

    Sammanfattning : This thesis presents palaeoenvironmental data from equatorial Africa covering two important time intervals; i) the warming period forming the Pleistocene/Holocene transition and ii) the last millennium. The Empakaai Crater, in northern Tanzania contains a lake from where sediment cores, spanning two time-slices 14.8-9. LÄS MER

  3. 2. Holocene vegetation dynamics and climate changes in the Torneträsk area, northern Sweden

    Författare :Lena Barnekow; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleobotanik; palynology; phylogeny; Palaeobotany; northern Sweden; Torneträsk; Abisko; lake-level; radiocarbon dating; forest history; Holocene; tree-line; climate; Vegetation; fylogeni; palynologi; Physical geography; geomorphology; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

    Sammanfattning : The aim of this study was to reconstruct the Holocene vegetation history and the climate changes in a subarctic area. The results are based on pollen and macrofossil records from six lakes in the Torneträsk area. The lakes are situated at altitudes between 370 and 999 m a.s. LÄS MER

  4. 3. Simulating the palaeorecord of northern European lakes using a coupled lake-catchment model

    Författare :Jüri Vassiljev; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climatology; cartography; pedology; geomorphology; Physical geography; northern Europe; catchment geometry; Holocene; overflow lakes; climate change; Water- and energy-balance modelling; lake-level changes; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi; Geophysics; physical oceanography; meteorology; Geofysik; fysisk oceanografi; meteorologi;

    Sammanfattning : A coupled lake-catchment model was developed to examine the controls on lake-level changes in currently overflowing lakes during Holocene. The lake energy-balance is simulated as the one-dimensional vertical heat transfer by eddy diffusion and convective mixing. LÄS MER

  5. 4. Stormy records from peat bogs in south-west Sweden : implications for regional climatic variability and vegetation changes during the past 6500 years

    Författare :Rixt de Jong; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Holocene climate; south-west Sweden; aeolian activity; humidity changes; vegetation development; REVEALS vegetation modelling; atmospheric circulation changes; peat sediments;

    Sammanfattning : This thesis aims to reconstruct and explain variations in storm activity, humidity, vegetation composition and land cover in south-west Sweden during the past 6500 years. Two ombrotrophic bogs, Store Mosse and Undarsmosse, situated on the coastal plain of Halland, were selected for this purpose. LÄS MER

  7. 5. Paleoenvironmental and paleoclimatic changes in northeast Thailand during the Holocene

    Författare :Sakonvan Chawchai; Barbara Wohlfarth; Richard Bindler; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleoenvironment; paleoclimatic; sediment; peat; multi-proxy; Asian monsoon; the Holocene; Marine Geology; maringeologi;

    Sammanfattning : The long-term climatic and environmental history of Southeast Asia is still fragmentary. This thesis therefore aims at studying lake sediment/peat sequences using a multi-proxy approach to reconstruct the environmental history and the impact of past changes in monsoon variability and intensity on lake ecosystems in Thailand. LÄS MER