Sökning: "Natural river"

Visar resultat 1 - 5 av 288 avhandlingar innehållade orden Natural river.

  1. 1. Geographical Distribution of Disasters Caused by Natural Hazards in Data-scarce Areas : Methodological exploration on the Samala River catchment, Guatemala

    Författare :Agnes Jane Soto Gómez; Veijo Pohjola; Allan Rodhe; Giuliano di Baldassarre; Günter Blöschl; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; natural disasters; Guatemala; data-scarce areas; natural disaster science methods; natural disaster maps; Geovetenskap med inriktning mot naturgeografi; Earth Science with specialization in Physical Geography;

    Sammanfattning : An increasing trend in both the number of disasters and affected people has been observed, especially during the second half of the 20th century. The physical, economic and social impact that natural hazards have had on a global scale has prompted an increasing interest of governments, international institutions and the academia. LÄS MER

  3. 2. Iron in the Lena River basin, NE Russia : Insights from microscopy, spectroscopy and isotope analysis

    Författare :Catherine Hirst; Carl-Magnus Mörth; Per Andersson; Mats Erik Åström; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; iron; reactivity; isotopes; permafrost; river; Arctic; Marine Geology; maringeologi;

    Sammanfattning : Iron is an important mediator of biotic and abiotic processes on the Earth’s surface, being an electron acceptor in organic matter degradation, a surface for organic matter and trace element adsorption, and a required element for enzymatic processes during primary production. Yet, the role of iron as a mediator of carbon and trace element cycling in high latitude, permafrost-dominated regions remains poorly investigated. LÄS MER

  4. 3. A Spatial Scale Approach to Fish Habitat Ecology and Impacted Rivers

    Författare :Henry H. Hansen; Eva Bergman; Max Lindmark; Dana Infante; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fish Habitat Models; River Ecology; Novel Riverscapes; Spatial Scale; Fish Communities; Anthropogenic Impacts; Sustainability; River Management; River Restoration; Biology; Biologi;

    Sammanfattning : Fish biodiversity in rivers is threatened by continual habitat loss. Evidence to support management and restoration of rivers requires information about the specific habitat requirements for entire fish communities. LÄS MER

  5. 4. Indirect effects of river regulation : consequences for landbirds of reduced numbers of aquatic insects

    Författare :Darius Strasevicius; Björn Malmqvist; Tapio Eeva; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boreal region; Simuliidae; Leucocytozoon; pied flycatcher; aquatic insects; breeding success; blood parasites; bird communities; river regulation; impoundment; Biology; Biologi;

    Sammanfattning : Abstrakt: Jag har undersökt hur älvreglering påverkar mängden knott (Tvåvingar: Simuliidae) längs flera norrlandsälvar och vilka konsekvenser denna påverkan får för den landlevande fågelfaunan. Studien visar att utbyggnad av älvar har en negativ effekt på mängden knott. LÄS MER

  7. 5. Hydrogeochemical effects of hydropower regulation on river-aquifer continuum in boreal rivers

    Författare :Dmytro Siergieiev; Hjalmar Laudon; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geochemistry; hyporheic zone; hydrology; riparian zone; Element transport; Lule River; Kalix RIver; Northern Sweden; Earth sciences; Applied Geology; Tillämpad geologi;

    Sammanfattning : Hydropower infrastructure affects many large rivers worldwide, threatening riverine and coastal ecosystems by fragmenting flow, disturbing landscapes and water retention and altering sedimentation and primary production. This thesis investigated major impacts of hydropower regulation on hydrological and geochemical processes in large boreal rivers. LÄS MER