Sökning: "LUE model"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden LUE model.

1. 1. Solar Wind Proton Interactions with Lunar Magnetic Anomalies and Regolith

   Författare :Charles Lue; Yoshifumi Futaana; Stas Barabash; Urs Mall; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; the Moon; solar wind; magnetic anomalies; regolith; space physics; plasma physics; particle-surface interactions; mini-magnetospheres; energetic neutral atoms; Space Physics; rymdfysik;

   Sammanfattning : The lunar space environment is shaped by the interaction between the Moon and the solar wind. In the present thesis, we investigate two aspects of this interaction, namely the interaction between solar wind protons and lunar crustal magnetic anomalies, and the interaction between solar wind protons and lunar regolith. LÄS MER

3. 2. Mapping Primary Production for the West African Sahel with Satellite Data

   Författare :Jonathan Seaquist; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography; Sahel; CENTURY; Monte Carlo; GPP; transpiration; LUE; CLAVR; PAR; compositing; MVC; geostatistics; noise; NDVI; NOAA AVHRR; geomorphology; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

   Sammanfattning : A light Use Efficiency (LUE) model is developed that allows the mapping of total growing season Gross Primary Production (GPP) for the West African Sahel, using the Normalized Difference Vegetation Index (NDVI) together with other data. Image quality may be poor in monthly NDVI maximum value composites as shown by an improved geostatistical noise estimation technique. LÄS MER

4. 3. Land degradation and mitigation in northern China. Evaluated from the biological production

   Författare :Micael Runnström; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marklära; geomorfologi; Fysisk geografi; climatology; kartografi; klimatologi; cartography; pedology; desertification; China; GPP; Mu Us; LUE-model; overgrazing; Physical geography; geomorphology;

   Sammanfattning : Land degradation is commonly perceived to be severe in many parts of semi arid China. The transition towards market economy since the 1978 reforms, have set marginal dry lands under added pressure in the form of increased livestock numbers and expanding cultivation on erosive soils. LÄS MER

5. 4. Recent changes in land use and productivity in agro-pastoral Inner Mongolia, China

   Författare :Sara Brogaard; LUCSUS; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geomorphology; Physical geography; China; Inner Mongolia; remote sensing; LUE model; primary production; GPP; yield variability; land degradation; farmers’ perception; productivity; Land use; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

   Sammanfattning : This study challenges the prevailing assumption that the expansion of cultivated land areas and increasing number of livestock in the agro-pastoral regions of northern China have aggravated the process of land degradation since the start of the rural reforms in 1978. Land-use and productivity trends in the Inner Mongolia Autonomous Region (IMAR), with special attention to the Keerqin steppe region, have been analysed. LÄS MER

7. 5. Model development for estimating carbon dioxide exchange in Nordic forests and peatlands with MODIS time series data

   Författare :Per Schubert; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The ongoing increase in atmospheric greenhouse gas concentrations causes an increase in the global mean air temperature. One important moderator of the atmospheric carbon dioxide (CO2) concentration is the gas exchange between the atmosphere and the biosphere; photosynthesis extracts and respiration releases CO2, resulting in a net exchange. LÄS MER