MONITORING OF VEGETATION TRENDS WITH MERIS TIME SERIES IN ARID IRRIGATED DRYLANDS OF CENTRAL ASIA

摘要

In fragmented landscapes of drylands, satellite data of arnmedium to high spatial resolution can capture accuratelyrngradual terrestrial processes such as land degradation. Arnpotential of the MERIS data was investigated forrnquantifying the gradual changes in irrigated croplands ofrnarid Uzbekistan in Central Asia. The MERIS full resolutionrntime series of NDVI images were employed over thernobservation period of 2003-2011. The results showed arnspatial distribution of the vegetation trends at a per-pixelrnlevel with a spatially-differentiated pattern of the negativerntrend, which could be attributed to cropland degradation.rnThe MERIS and MODIS NDVI-based trend coefficientsrnwere not significantly correlated (R~2=0.42), probably due torninitial differences in the spectral and spatial resolution of thernsensors and image processing applied.