Sökning: "hyporheic zone"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden hyporheic zone.

  1. 1. Transformation of Micropollutants in the Hyporheic Zone

    Författare :Malte Posselt; Jonathan P. Benskin; Michael Radke; Merle Plassmann; Magnus Breitholtz; Ian Cousins; Gudrun Massmann; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; micropollutants; hyporheic zone; biodegradation; bacteria; pharmaceuticals; transformation products; LC-MS MS; macrophytes; bedforms; suspect screening; mesocosm; flume; river; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : Hyporheic zones (HZs) are reactive transition regions between rivers and aquifers which are thought to play an important role in the attenuation of micropollutants. Micropollutants are chemical substances such as pharmaceuticals, industrial chemicals or personal care products that are found in trace concentrations in the environment and that can be harmful to organisms. LÄS MER

  3. 2. 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

  4. 3. Impact of hydropower regulation on river water geochemistry and hyporheic exchange

    Författare :Dmytro Siergieiev; Hjalmar Laudon; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; regulated river; hyporheic zone; hydraulic conductivity; clogging layer; Applied Geology; Tillämpad geologi;

    Sammanfattning : Hydropower regulation of rivers exhibits a threat to the riverine ecosystems. Fragmentation of flow, landscape disturbances, and water retention are key features of regulated catchments, resulting in reduced floods and geochemical tr¬ansport, non-natural water level fluctuations, and thus disturbed exchange between the river and the aquifer. LÄS MER

  5. 4. Multi-Scale Surface Water-Groundwater Interaction : Implications for GroundwaterDischarge Patterns

    Författare :Babak Brian Mojarrad; Anders Wörman; Joakim Riml; Jan Fleckenstein; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; groundwater flow; hyporheic zone; multi-scale modeling; spectral analysis; fragmentation of discharge zones; characteristic parameters; Hydraulik och teknisk hydrologi; Hydraulic and Hydrologic Engineering;

    Sammanfattning : Rivers and aquifers are continuously exchanging water, driven by processes that occur on various temporal and spatial scales, ranging from small streambed features to large geological structures. The interaction between these two components occurs in permeable sediments below the stream channel, called the hyporheic zone. LÄS MER

  7. 5. Effect of Hyporheic Exchange on Conservative and Reactive Solute Transport in Streams : Model Assessments Based on Tracer Tests

    Författare :Karin Jonsson; Anders Wörman; Bernhard H. Schmid; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; conservative; hyporheic exchange; model; reactive; retention; solute; sorption kinetics; stream transport; temporal moments; tracer experiment; Geovetenskap; Earth sciences; Geovetenskap; Sedimentology; sedimentologi;

    Sammanfattning : Understanding of the processes affecting solute transport in flowing water is important for the possibility to predict the evolution with time of polluted stream systems. This thesis presents tracer experiment methodology and model developments for solute transport in streams, with special focus on retention processes and their effect on solute stream transport. LÄS MER