IADO   05364
INSTITUTO ARGENTINO DE OCEANOGRAFIA
Unidad Ejecutora - UE
artículos
Título:
Spatial and temporal patterns of rainfall variability and its relationship with land surface phenology in central east Argentina
Autor/es:
CELLERI, CARLA; PRATOLONGO, PAULA; ZAPPERI, GEORGINA; GONZÁLEZ TRILLA, GABRIELA
Revista:
INTERNATIONAL JOURNAL OF CLIMATOLOGY
Editorial:
JOHN WILEY & SONS LTD
Referencias:
Año: 2018 vol. 38 p. 3963 - 3975
ISSN:
0899-8418
Resumen:
Transition zones between dry and humid climates are highly sensitive areas wheresmall changes in the spatial and temporal distribution of rainfall may have vastconsequences on vegetation development. Rainfall regimes are expected to changeworldwide and predictions include variations in total annual precipitation and timingof rain events. In this context, evaluating the relationship between vegetationactivity and rainfall variability along transition zones is particularly relevant. Inthis study, 54 years (1961?2013) of gridded monthly rainfall data (ClimaticResearch Unit Time-Series Version 3.22 [CRU TS3.22]) were used to analyseannual and inter-annual rainfall variability. Land surface phenology (LSP) metrics(2000?2013) were derived from MODIS 16-day composites Normalized DifferenceVegetation Index (NDVI) data (MOD13Q1 product) and relationshipbetween rainfall variability and LSP metrics was assessed. Annual rainfall showeda strong seasonality in the northeast of the study area that diminishes towards thesouthwest. Inter-annual rainfall variability, which showed a significant 8-yearcycle periodicity after 1980, was stronger in the southwest of the region. For mostof the study area, summer rainfall (November?January) showed significant negativecorrelation with August?October Southern Oscillation Index (SOI) average,although this connection was not reflected in annual precipitation totals. Regardingvegetation response to rainfall variability, two main areas were identifiedwhere differences in LSP metrics between wet and dry years were larger than theaverage. The first one was a zone within the humid to semi-arid transition belt,where NDVI maximum, NDVI amplitude and NDVI integral showed highervalues during wet years. The second one was the central north area, which showedhigher NDVI amplitude values during dry years. In the study area, water availabilityis a sensitive issue for natural ecosystems, agriculture and cattle-raising. Theseresults provide a better understanding of the relationship between rainfall variabilityand vegetation changes, which is useful information for the development offuture management policies.