c8d2937f-3799-4aac-8e7d-ac9a492bc13b eng Zhanguo Bai 2012-02-22T15:13:25 ISO 19115:2003/19139 1.0 2 0.072727 0.072727 yes GCS_WGS_1984 Global Pattern, Trends and Confidence Levels of NDVI Coefficient of Variation (1981-2003) 2008-10-22T07:00:00 First edition Coefficient of variation (CoV) can be used to compare the amount of variation in different sets of sample data. NDVI CoV images were generated by computing for each pixel the standard deviation of the set of individual NDVI values and dividing this by the mean of these values. It is recommended that the maps should be considered in the field investigation - in particular the land use change during the study period (1981- 2003). A positive change in the value of a pixel-level CoV over time relates to increased dispersion of values, not increasing NDVI; similarly, a negative CoV dispersion – which is the case over nearly the whole country - means decreasing dispersion of NDVI around mean values, not decreasing NDVI. NDVI CoV is used to represent the dispersion of NDVI values relative to the mean value. Food and Agriculture Organization of United Nations - HQs Viale delle Terme di Caracalla Rome 00153 Italy ISRIC - World Soil Information +31 (0)317 483 735 Duivendaal 9 Wageningen Wageningen 6701 AR The Netherlands soil.isric@wur.nl UN FAO - HQs Director of Land and Water Division Viale delle Terme di Caracalla Rome 00153 Italy NRL-Director@fao.org S7abcd_s.gif thumbnail gif S7abcd.gif large_thumbnail gif NDVI Land degradation Land improvement Remote sensing Rain-use efficiency GLADA World eng environment 1981-07-01T07:00:00 2003-12-01T13:56:00 -180 180 -90 90 Within the FAO program Land Degradation Assessment in Drylands (LADA), the present "Global Assessment of Land Degradation and Improvement" uses remote sensing to identify areas where significant biological change is happening, both hot spots of land degradation and bright spots of land improvement. In the next phase of the program, hot spots and bright spots will be further characterised in the field by national teams. http://www.isric.org WWW:LINK-1.0-http--link ISRIC - World Soil Information website http://www.fao.org:80/geonetwork/srv/en/resources.get?id=37060&fname=Global NDVI coefficient of variation Fig S7a.zip&access=private WWW:DOWNLOAD-1.0-http--download Global NDVI coefficient of variation Fig S7a.zip Global multi-year mean annual NDVI coefficient of variation 1981-2003 http://www.fao.org:80/geonetwork/srv/en/resources.get?id=37060&fname=Global NDVI coefficient of variation Fig S7b.zip&access=private WWW:DOWNLOAD-1.0-http--download Global NDVI coefficient of variation Fig S7b.zip Global trend in annual NDVI coefficient of variation 1981-2003 (% change) http://www.fao.org/nr/lada/index.php?/Global.html WWW:LINK-1.0-http--link LADA - Land Degradation Assessment in Drylands - FAO 2008 Web site http://www.fao.org:80/geonetwork/srv/en/resources.get?id=37060&fname=Global NDVI coefficient of variation Fig S7c.zip&access=private WWW:DOWNLOAD-1.0-http--download Global NDVI coefficient of variation Fig S7c.zip Global changes in annual NDVI coefficient of variation 1981-2003 (absolute change) http://www.fao.org:80/geonetwork/srv/en/resources.get?id=37060&fname=Global NDVI coefficient of variation Fig S7d.zip&access=private WWW:DOWNLOAD-1.0-http--download Global NDVI coefficient of variation Fig S7d.zip Global confidence levels of trend in annual NDVI coefficient of variation 1981-2003 http://www.fao.org:80/geonetwork/srv/en/resources.get?id=37060&fname=GLADA Report 5.pdf&access=private WWW:DOWNLOAD-1.0-http--download GLADA Report 5.pdf GLADA Report 5 - Global Assessment of Land Degradation and Improvement- PDF format http://data.fao.org/maps/wms?styles=geonetwork_figs7a_37060_style OGC:WMS-1.1.1-http-get-map GEONETWORK:figs7a_37060 Global multi-year mean annual NDVI coefficient of variation 1981-2003 http://data.fao.org/maps/wms?styles=geonetwork_figs7b_37060_style OGC:WMS-1.1.1-http-get-map GEONETWORK:figs7b_37060 Global trend in annual NDVI coefficient of variation 1981-2003 (% change) http://data.fao.org/maps/wms?styles=geonetwork_figs7c_37060_style OGC:WMS-1.1.1-http-get-map GEONETWORK:figs7c_37060 Global changes in annual NDVI coefficient of variation 1981-2003 (absolute change) http://data.fao.org/maps/wms?styles=geonetwork_figs7d_37060_style OGC:WMS-1.1.1-http-get-map GEONETWORK:figs7d_37060 Global confidence levels of trend in annual NDVI coefficient of variation 1981-2003 Last Updated 2008-10-30T15:34:00