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Impact of deflorestation on Hydrological Cycle in Eastern Amazonia

Josivan da Cruz Beltrão, UFPA, (Presenting)
Adilson Wagner Gandu, USP,
Julia Clarinda Paiva Cohen, UFPA,

The objective of this work was to evaluate the impact of deforestation on the hydrological cycle of the eastern Amazon basin, using BRAMS (Brazilian developments on the Regional Atmospheric Modeling System) including the GEMTM model (General Energy and Mass Transport Model). The eastern Amazonia is an area of primarily native tropical rain forest, but also comprises several other natural ecosystems such as mangroves and savannah-like vegetation. It is also the most densely populated area in Amazonia, and has been significantly affected by deforestation. In this study, numerical simulations were performed with a high spatial resolution regional model that allows for consideration of mesoscale aspects such as topography, coastlines and large rivers. In order to evaluate the present situation and to predict potential future effects of this process on the climatic conditions of this region, two model simulation runs, each conducted over a one-year period, were made. In the first run, designated “control simulation”, an attempt was made to match the existing surface vegetation. In the second simulation designated “deforestation” was running using scenarios derived from results of Soares-Filho (2002). The higher-resolution regional modelling revealed important climatic features of the deforestation process, displaying some associated mesoscale effects that are not typically represented in similar Global Circulation Model simulations. Near coastal zones and along large rivers, deforestation resulted in reduced precipitation. However, it was predicted increased precipitation over mountainous areas, especially on mountain slopes facing river valleys. Then, these higher-resolution simulations showed that, in general, orography, coastline profile and large river distribution play important roles in determining anomaly patterns of precipitation in eastern Amazonia.

Science Theme:  HY (Hydrometeorology)

Presentation Type:  Poster

Abstract ID: 33

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