Sökning: "hyporheic exchange"

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

1. 1. 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

3. 2. 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

4. 3. 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

5. 4. The influence of multiscale hyporheic flow on solute transport : Implications for stream restoration enhancing nitrogen removal

   Författare :Ida Morén; Anders Wörman; Joakim Riml; Roy Haggerty; KTH; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Hyporheic exchange flow; Hydrological modeling; Solute transport; Stream restoration; Nitrogen; Power spectral analysis; Hydraulic and Hydrologic Engineering; Hydraulik och teknisk hydrologi;

   Sammanfattning : Stream water that flows into and out of streambeds is called hyporheic exchange flow (HEF).It continuously interacts with groundwater and thereby affect the water quality of local streamreaches as well as downstream recipients by providing an environment where solutes andenergy can be retained and degraded. LÄS MER

7. 5. 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