Disentangling the effects of hydro-climatic factors and land use intensification on wetland vegetation dynamics in the Lower Delta of the Paran´a River

AQUINO, DIEGO SEBASTIÁN; GAVIER, GREGORIO; QUINTANA, RUBÉN D.

Remote Sensing Applications: Society and Environment

elsevier

Año: 2021 vol. 21

2352-9385

The non-insular portion of the Lower Delta of the Paran´a River is part of the largest mosaic of wetlands inArgentina. However, it is being altered by intensification of cattle grazing and the increasingly rapid implementationof water management infrastructure. In this context, studying the relationship between hydro-climaticvariables and vegetation growth is urgent to ensure sound management and conservation. To overcome thelimitation of high cloud cover in the area which has hampered the construction of regularly spaced highresolutiontime series, we implemented the recently developed spatio-temporal vegetation index image fusionmodel (STVIFM). In order to understand the relationship between vegetation growth and hydro-climatic factors,we performed pixel-wise correlation analyses between the newly synthesized monthly (30m) NDVI time seriesand hydro-climatic variables. Then, we tested whether water control infrastructure alters these relationships.Based on the accurate performance of STVIFM, we provide quantitative and spatially accurate evidence on thepositive, complementary and heterogeneous relationships between vegetation growth, temperature, rainfall andthe flood pulse. Our results show that water management infrastructure decouples certain areas from its naturalhydrological regime, decreasing water availability and altering vegetation growth dynamics. In this context,urgent action is needed aimed towards implementing land planning measures that consider the natural variabilityand hydrologic regime of the system while balancing production and conservation.