SUMMARY
The Hydraulic Concepts Model Distributed from Large Basins of the Hydraulic Research Institute (MGB-IPH) is a rainfall-type model validated in several basins in South America, including in rivers of the Amazon Basin. The inputs of the model are climatological, rainfall, relief and soil cover data. The objective of this study is to test the sensitivity of the model in extreme scenarios of soil use and occupation, changes in precipitation and mean air temperature. The case study was carried out in the Curuá-Una river basin, located southeast of Santarém-Pará. The MapWindow-GIS software and the IPH-Hydro Tools plug-in were used in the preprocessing, and the MGB-IPH plugin was processed. The results showed that the MGB-IPH has sensitivity to changes in soil use, precipitation and mean air temperature. In the sensitivity test of soil use and occupation the results showed that low vegetation and anthropization increase the maximum peaks of flow; In periods of Amazon flood with low rainfall occurrence, the low vegetation scenario has a higher flow rate; And the forest scenery prevents intense floods. In the tests of changes in the precipitation regime, a 50% decrease in rainfall reduced the flow by 32% and a 50% increase in rainfall increased the flow by 218.6%. However, in the tests of increase of the mean air temperature the results did not show significant responses in the flow regime, however, this scenario, added with the increase and / or decrease of the precipitation regime, presented as attenuator for both floods and droughts.