Sökning: "soil heterogeneity"

Visar resultat 6 - 10 av 38 avhandlingar innehållade orden soil heterogeneity.

1. 6. Evaporation and Heat-flux Aggregation in Heterogeneous Boreal Landscapes

   Författare :Tony Persson; Sven Halldin; Dimitris Melas; Deliang Chen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrology; land-surface processes; heterogeneity; surface fluxes; soil-water content; high latitudes; snow; lakes; climate; mesoscale model; NOPEX; WINTEX; Hydrologi; Hydrology; Hydrologi;

   Sammanfattning : The boreal forests represent 8 % of all forested areas on the earth and have a significant role in the control of greenhouse gases and an impact on global climate change. The main objective of this thesis is to increase the understanding of how evaporation and heat-flux processes in the boreal forest zone are affecting the regional and global climate. LÄS MER

3. 7. Groundwater Recharge in Crystalline Bedrock : Processes, Estimation, and Modelling

   Författare :Niclas Bockgård; Sven Halldin; Allan Rodhe; Auli Niemi; Lars O. Ericsson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrology; groundwater recharge; bedrock; crystalline rocks; tracers; CFC; surface loading; loading efficiency; barometric effect; heterogeneity; stochastic modelling; Hydrologi; Hydrology; Hydrologi;

   Sammanfattning : Kunskap om grundvattenbildningen är nödvändig för att man ska kunna förutsäga konsekvenserna av grundvattenuttag och underjordsbyggande. Grundvattenbildningen i berggrunden är dock svår att uppskatta. LÄS MER

4. 8. Unsaturated Solute Transport in a Semiarid Catchment - Nonlinear Analyses and Modelling

   Författare :Pernilla Öhrström; Avdelningen för Teknisk vattenresurslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; teknisk geografi; Hydrogeologi; teknisk geologi; unsaturated zone; Hydrogeology; geographical and geological engineering; solute transport; scaling; soils; semiarid regions; heterogeneity; preferential flow; fractals;

   Sammanfattning : Unsaturated solute transport is highly variable and therefore difficult to predict. In semi-arid areas, where water resources are limited, the presence of macropores is of great importance for crop production. The bromide ion (Br-) and dye tracers are useful for studies of water movement. LÄS MER

5. 9. Permafrost carbon in a changing Arctic : On periglacial landscape dynamics, organic matter characteristics, and the stability of a globally significant carbon pool

   Författare :Niels Weiss; Peter Kuhry; Duane Froese; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Permafrost; Carbon; Climate; Arctic; Soil; Organic Matter; Cryosphere; Geomorphology; Physical Geography; naturgeografi;

   Sammanfattning : Organic matter (OM) in arctic permafrost ground contains about twice as much carbon (C) as is currently present in the atmosphere. Climate change is particularly strong in the Arctic, and could cause a considerable part of the OM in permafrost to thaw out, decompose, and be released as greenhouse gases; further enhancing global warming. LÄS MER

7. 10. Solute transport in the integrated soil-groundwater system

   Författare :Eva Simic; KTH; []
   Nyckelord :solute transport; groundwater transport; integrated soil.groundwater system;

   Sammanfattning : A Lagrangian stochastic travel time approach has been usedfor investigating dominant process impacts on (non-reactive andreactive) solute transport in the integrated soil-groundwatersystem. A first step has also been taken to extending thisLagrangian stochastic travel time approach to integrate thesoil-groundwater-stream transport through a catchment. LÄS MER