Evaluation of the Environmental Impacts Caused by Deforestation in the Hydric Regimen of the Metropolitan Region of Petrópolis (rj), Brazil

Vegetation has closer relationship with the hydrological cycle, changing them due to their conditions. Vegetation regulates the hydrological cycle making water faces all the stages adequately causing the process stability. Vegetation retains great parcel of the rainwater, freeing it for the water courses and surface and subterranean reservoirs, little by little. In this work, the impact of deforestation over the hydric regimen of the City of Petrópolis was analyzed. The results show that the reduction of vegetation coverage provoked annual outflows increases. The reduction of the vegetation coverage from 58% to 39% caused addictions in average outflow of 60%. This brought the increase of the draining index from 0.29 to 0.50. Changes are also verified concerning the annual average minimum and maximum outflows. In the first case, there was an increase of 86,3% and, in the second case, the annual average maximum outflow was increased in 49,9%.