This work focuses on the hydrological response (ie precipitation, discharge and
evapotranspiration) to deforestation, for two individual basins, where the processes of
changing vegetation cover are at different levels. Search is thus ratifying the results
mentioned in literature in the sense that above certain level of deforestation
hydrological responses are to give due to local and non-local atmospheric
interactions. Two basins were seleceted: the Curua-Una (micro-region of Santarem
PA) and Uraim (Paragominas-PA). These basins were chosen because they
represent examples of two different situations in respect of the advance of
deforestation. The first is at a level of approximately 25%, while the second basin has
experienced even more significant deforestation in the order of 65%. Using the time
series data were performed for each basin statistical analysis to test the hydrological
differences between two periods, representing different situations of deforestation,
that is, a more preserved moment and a more deforested one. The results confirm
that, in fact, different levels of deforestation cause different hydrological responses, to
point out that for the basin with lower levels of deforestation 25% (i.e. Curua-Una
Basin) there is not significant change in precipitation and even so the discharge
increases, while the most devastated area (i.e. Uraim Basin) shows a reduction in
precipitation (ranging from 25%), consequently decreasing the channel’s flow. These
results are particularly relevant for confirming with field data that the assumptions
made by various simulations of future scenarios in practice are already occurring, if
not on a regional level, at least for one specific area where the level of deforestation
is enhanced both as a percentage as of total length.
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