Search for dissertations about: "vegetation ndvi"

Showing result 1 - 5 of 12 swedish dissertations containing the words vegetation ndvi.

2. 1. Circumpolar impacts of herbivores on Arctic tundra vegetation

   Author : Elin Lindén; Johan Olofsson; Maja K. Sundqvist; Mariska te Beest; Elisabeth S. Bakker; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; herbivores; grazing; Arctic; circumpolar; tundra; vegetation; plant defence; secondary metabolites; shrub birch; exclosures; vegetation; species diversity; biology; biologi;

   Abstract : Arctic tundra vegetation provides many ecological services that have implications for the global climate. However, the tundra biome is currently changing in response to increasing temperatures. Herbivores may mitigate some of these responses to warming through their impact on Arctic vegetation. READ MORE

4. 2. Analyzing Vegetation Trends with Sensor Data from Earth Observation Satellites

   Author : Sadegh Jamali; Institutionen för naturgeografi och ekosystemvetenskap; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Change detection; Satellite sensor data; Time series analysis; Vegetation dynamics; Vegetation index;

   Abstract : Abstract This thesis aims to advance the analysis of nonlinear trends in time series of vegetation data from Earth observation satellite sensors. This is accomplished by developing fast, efficient methods suitable for large volumes of data. READ MORE

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

   Author : Jonathan Seaquist; Institutionen för naturgeografi och ekosystemvetenskap; []
   Keywords : 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;

   Abstract : 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. READ MORE

6. 4. Towards Climate Based Early Warning and Response Systems for Malaria

   Author : Maquins Odhiambo Sewe; Joacim Rocklöv; Clas Ahlm; Yesim Tozan; Madeleine Thomson; Umeå universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Malaria; Mosquito; Lead time; Early Warnings; Forecasts; Economic Evaluation; Rainfall; KEMRI CDC HDSS; Kenya; Temperature; LST; NDVI; Climate; HDSS; GAM; GAMBOOST; DLNM; Remote Sensing; Net Benefit; Cost-Effectiveness; Boosting Regression; Weather; Public Health; Infectious Diseases; folkhälsa; Public health; Epidemiology; epidemiologi;

   Abstract : Background: Great strides have been made in combating malaria, however, the indicators in sub Saharan Africa still do not show promise for elimination in the near future as malaria infections still result in high morbidity and mortality among children. The abundance of the malaria-transmitting mosquito vectors in these regions are driven by climate suitability. READ MORE

7. 5. Bush Encroachment and the Role of Browse in Cattle Production : An ecological perspective from a bush encroached grazing system, Olifants Drift, Kgatleng District, Southeast Botswana

   Author : Nkobi Moleele; Norman Owen-Smith; Stockholms universitet; []
   Keywords : savannas; bush encroachment; carrying capacity; browse; biomass; range degradation; colour infrared photographs; Landsat Thematic Mapper; mid infrared bands; tannins; toxins; aromatic substances; Dicrostachys cinerea; Grewia flava; NDVI; Olifants Drift; Botswana; naturgeografi; Physical Geography;

   Abstract : The increase in density and cover of woody plant species is coincident with the introduction of cattle in southern Africa, and it is a wide spread phenomenon in the savannas of the world. The causes are little understood, but can only be speculated to be either anthropogenic or natural or a combination of both. READ MORE