NDVI patterns as indicator of morphodynamic activity in the middle Paraná River floodplain

MARCHETTI, ZY; MINOTTI, PG; RAMONELL, CG; SCHIVO, F; KANDUS, P

GEOMORPHOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 253 p. 146 - 158

0169-555X

Thiswork assesses the performance of a 2000?2014NDVI-MODIS time-series to identify areas of the Paraná Riverfloodplain associated with different morphodynamic areas and hence ecological behavior. From classificationprocedures we obtained six NDVI patterns (P1 to P6) differing in their mean values, standard deviation, and seasonality.The NDVI patterns are evidence of different situations in terms of elevation, flood dynamics, and vegetationphysiognomies: P1 represents water bodies, P2 to P4 cover frequently flooded lowlands colonized bymarshy vegetation, and P5 and P6 are placed on middle and high elevations that are less flooded and also are coveredby tall vegetation (grassland and forest). Instead of differences among the six NDVI patterns, they showed aspatial arrangement that allowed the identification of two parallel belts; belt I, formed by P2 to P4, is placed closeto the Paraná River and its connected branches; while belt II, formed by P5 and mainly P6, appears on themarginal floodplain far away fromthe main channels. The spatial arrangement of the two belts is similar to limitsfollowed by the morphodynamic areas of the Paraná fluvial system. More than 60% of the surface covered by P2and P5 corresponds to low morphodynamic areas while nearly 70% of P6 matches with high morphodynamicareas. Through their annual and interannual behavior, spatial arrangement, and relationship with morphodynamicareas, the NDVI patterns allow the interpretation of lateral organization of the Paraná River floodplain.This paper exploits the potential of time-series of NDVI to understand, from a synoptic point of view, the floodplaindynamics by capturing the seasonal and interannual variability of vegetation physiognomies andhydrosedimentological regime along and across the floodplain.