Sökning: "Soil dynamics"

Visar resultat 11 - 15 av 169 avhandlingar innehållade orden Soil dynamics.

  1. 11. Making the Most of It? : Understanding the social and productive dynamics of small farmers in semi-arid Iringa, Tanzania

    Författare :Peter Gregersen; Sociologi; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Social changes; Malthus; Boserup; Tanzania; semi-arid Africa; Iringa; conservation; sustainability; soil fertility; degradation; population; Matthew principle; social differentiation; farmerisation; de-peasantisation; livelihood diversification; rural change; agrarian change; agricultural change; small farmers; dynamics; theory of social work; Sociala förändringar; teorier om socialt arbete; Malthus; Boserup; Tanzania;

    Sammanfattning : While much of semi-arid Africa is still sparsely populated with unused land, there are everywhere pockets of high and increasing population density in attractive locations. Small-scale farmers can respond to beginning land-scarcity in a number of ways. LÄS MER

  3. 12. Dynamic soil-structure interaction of simply supported high-speed railway bridges

    Författare :Johan Lind Östlund; Jean-Marc Battini; Andreas Andersson; Mahir Ülker-Kaustell; Rui Calçada; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic soil-structure interaction; Railway bridge; Impedance function; Soil dynamics; High-speed train; Structural Engineering and Bridges; Bro- och stålbyggnad;

    Sammanfattning : Research performed on the subject of dynamic soil-structure interaction (SS) concerning railway bridges is presented in this thesis with the focus on simply supported railway bridges supported by shallow foundations in soil strata on bedrock. The research aims to obtain insight into the SSI of high-speed railway bridges and to provide recommendations on how to model the soil-bridge system from a design perspective. LÄS MER

  4. 13. Nitrogen in soil water of coniferous forests : effects of anthropogenic disturbances

    Författare :Martin Rappe George; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : In boreal and temperate forests, long-term elevated nitrogen (N) load may eventually saturate forest ecosystems with N, i.e. total N ecosystem input exceed ecosystem sinks for N, and N losses via soil water transport may then increase and negatively impact environmental quality. LÄS MER

  5. 14. Micronutrients in cereal crops : impact of nutrient management and soil properties

    Författare :Karin Hamnér; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Seven elements essential for plants are defined as micronutrients: boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni) and zinc (Zn). Deficiency of these nutrients can cause yield losses in crops and impaired crop quality. LÄS MER

  7. 15. Permafrost Groundwater Dynamics : Modeling of vertical and lateral flows in the active layer across multiple scales

    Författare :Alexandra Hamm; Andrew Frampton; Peter Kuhry; Jeffrey McKenzie; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; permafrost; climate change; numerical modeling; hydrogeology; groundwater; naturgeografi; Physical Geography;

    Sammanfattning : Hydrological processes in the Arctic are profoundly influenced by the presence of permanently frozen ground, known as permafrost. Conversely, permafrost is greatly affected by hydrological changes resulting from climate change. LÄS MER