Sökning: "physical geography"

Visar resultat 21 - 25 av 433 avhandlingar innehållade orden physical geography.

1. 21. Carbon metabolism in clear-water and brown-water lakes

   Författare :Jenny Ask; Jan Karlsson; Mats Jansson; Rolf Vinebrooke; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; clear-water lakes; brown-water lakes; primary production; bacterial production; benthic; pelagic; net ecosystem production; allochthonous organic carbon; CO2; DOC; Physical geography; Naturgeografi; Freshwater ecology; Limnisk ekologi; limnologi; Limnology; naturgeografi; Physical Geography;

   Sammanfattning : The trophic state of lakes is commonly defined by the concentration of nutrients in the water column. High nutrient concentrations generate high phytoplankton production, and lakes with low nutrient concentrations are considered low-productive. LÄS MER

3. 22. Relationships between Atmospheric Circulation and Wind Erosion in Southern Sweden and Australia

   Författare :Marie Ekström; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi; Physical geography; geomorphology; Geologi; fysisk geografi; physical geography; Geology; sea level pressure; atmospheric circulation; erosivity; wind erosion; wind climatology; Scania; Australia;

   Sammanfattning : Wind erosion is a serious threat to soil resources as it causes depletion of the fine fractions that may result in a less fertile soil. Wind erosion encompasses several processes of which many are related to climate variables. To date, there is little work performed on how wind erosion relates to climate and climate change. LÄS MER

4. 23. Leaf Area Index of Scandinavian Forests Methods Using in situ and Remotely Sensed Data

   Författare :Helena Eriksson; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geologi; fysisk geografi; Physical geography; geomorphology; Geology; physical geography; leaf aggregation; specific leaf area SLA .; Växtekologi; Plant ecology; Leaf area index LAI ; canopy reflectance models; spectral vegetation indices; remote sensing; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

   Sammanfattning : This thesis deals with methods of obtaining the leaf area index (LAI) from remotely sensed satellite data. Initially, in situ estimation methods were investigated, since the accuracy of the remotely sensed estimates is dependent on the quality of these estimates. LÄS MER

5. 24. Glacial geology of Bayan Har Shan, northeastern Tibetan Plateau

   Författare :Jakob Heyman; Arjen P Stroeven; Clas Hättestrand; Helena Alexanderson; Mark D Johnson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography; Naturgeografi; Physical Geography; naturgeografi;

   Sammanfattning : The paleoglaciology of the Tibetan Plateau is still largely unexplored, despite its importance for regional and global climate reconstructions. In this thesis a comprehensive glacial geological record is presented from an extensive part of the northeastern Tibetan Plateau centred on the Bayan Har Shan. LÄS MER

7. 25. Spatial and Temporal Variations of Solifluction and Related Environmental Parameters in the Abisko Mountains, Northern Sweden

   Författare :Hanna Ridefelt; Jan Boelhouwers; Antoni Lewkowicz; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; solifluction; movement rates; Abisko region; Geographical Information Systems; statistical modelling; geomorphic work; permafrost; Physical geography; Naturgeografi; naturgeografi; Physical Geography;

   Sammanfattning : This thesis presents an assessment of the variation in solifluction occurrence, morphometry and movement rates in the Abisko region, northern Sweden. Variations in movement rates are analyzed both on a regional and local scale. LÄS MER