Sökning: "subsurface flow"

Visar resultat 1 - 5 av 38 avhandlingar innehållade orden subsurface flow.

  1. 1. Water and Heat Transport in Road Structures : Development of Mechanistic Models

    Författare :Klas Hansson; Lars-Christer Lundin; Kurt Roth; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrology; Water flow; Heat flow; Unsaturated flow; Freeze-thaw; Numerical models; Uncertainty analysis; Sensitivity analysis; Roads; Overland flow; Flow patterns; TDR; Water content reflectometer; Calibration; Fractures; Hydrologi; Hydrology; Hydrologi;

    Sammanfattning : The coupled transport of water and heat, involving freezing and thawing, in the road structure and its immediate environment is important to consider for optimal design and maintenance of roads and when assessing solute transport, of e.g. de-icing salt, from roads. LÄS MER

  3. 2. Nitrogen transformations in wetlands: Effects of water flow patterns

    Författare :Torbjörn Davidsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; hydrology; infiltration; subsurface flow; surface flow; wetland; nitrogen; Denitrification; mineralization; nitrification; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Sammanfattning : In this thesis, I have studied nitrogen turnover processes in watermeadows. A watermeadow is a wetland where water infiltrates through the soil of a grassland field. LÄS MER

  4. 3. Subsurface dams in water resource management : methods for assessment and location

    Författare :Imran Ali Jamali; Bo Olofsson; Stephen Foster; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Subsurface dams; Groundwater; GIS; Regolith thickness; Groundwater; Byggvetenskap; Civil and Architectural Engineering;

    Sammanfattning : Natural groundwater storage can be improved by constructing a subsurface barrier that is a subsurface dam, in order to capture the subsurface flows and raise the groundwater levels (GWLs) in the sediment layers. Subsurface dams are preferable to surface dams because of lower evaporation, higher functionality, lower cost of construction, lessened risk for contamination and the possibility of utilizing land over the dam. LÄS MER

  5. 4. Topographic Control of Groundwater Flow

    Författare :Lars Marklund; Anders Wörman; Shulan Xu; Roy Haggerty; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Groundwater; Modeling; Topography; Spectral analysis; Fourier series; Exact solu-tions; Multi-scale; Grundvatten; Modellering; Topografi; Spektralanalys; Fourier serier; Analytisk lösning; Flerskalig; Hydrology; Hydrologi; Environmental engineering; Miljöteknik;

    Sammanfattning : Gravity is the main driving force for groundwater flow, and both landscape topography and geology distribute the effects of gravity on groundwater flow.  The groundwater table defines the distribution of the potential energy of the water. LÄS MER

  7. 5. Three-Dimensional Simulation and Physical Modelling of Flows in Detention Tanks - Studies of Flow Pattern, Residence Time and Sedimentation

    Författare :Åsa Adamsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tracer study; pond; numerical simulation; particle tracking; CFD; bed shear stress; storage tank; stormwater; detention tank; flow pattern;

    Sammanfattning : Improving effluent water quality to receiving waters using stormwater ponds and storage tanks is acknowledged to be an effective method. The performance of the method depends however on flow conditions such as velocity distribution, short-circuiting currents and the volume through which the influent water flows, the so called effective volume. LÄS MER