ASSESSING
DROUGHT SEVERITY AND ITS IMPACT ON VEGETATION WITHIN
OLTENIA PLAIN USING NDVI FROM MODIS (2000-2010)
IRINA ONȚEL, GABRIELA MOROȘANU
ABSTRACT. - Assessing drought severity and its impact on vegetation within Oltenia Plain using NDVI from MODIS (2000-2010). Remote sensing is often used for detecting seasonal vegetation changes, treating a phenomenon both from a spatial and temporal perspective. Regional assessment of the drought has a huge importance in future studies and measures taken in order to diminish its negative effects in the agricultural sector. Considering this fact as a premise, the primary objective of our study aims at observing the impact on the vegetation of the wellknown and, probably, the most severe meteorological risk in Oltenia Plain, the drought, using the NDVI analysis and several drought indexes and correlations. At the same time, one of our goals was to see the characteristic periods of the drought by consulting the effects it has over the vegetation. Although a lot of work has been devoted to examining the drought on a temporal and spatial scale, the results were conclusive, showing a direct relation between the values of the rainfall and the phenological state of the vegetation. Our interest was accomplished via a multi-indices assessment of the drought impact, according to which, the binome vegetation – humidity proved to be the best way to estimate the drought periods in Oltenia Plain, as well as drought exposure and vulnerability.
Key words: drought, NDVI, Oltenia Plain, ”De Martonne” Index