Of course that the antrpica action tends to speed up this process, mainly when the intervention is made without the had knowledge, with incautiousness or indifference. The city of Brook of the Plaza comes being systematically deforested, being its used native vegetation as firewood and in the coal production; infrastructure workmanships, as the existing roads, cut to the hillsides and the riverbed removing the vegetation and displaying ground; springs, eyes d' water, rivers and streams have its ciliares bushes withdrawals, favoring the reduction of the outflow and, in some cases, the fast disappearance of sources. The ribeirense population originates from the miscegenation at the beginning enters the first tamers of century XX, slaves who had come here, after the abolition and the indians imbors. The estimate of the IBGE for the year of 2009 is for a population of 14.528 inhabitants as picture below, the population has agricultural and masculine predominance and with less than 35 years. The population of Brook of the Plaza got a reduction of the population number, had the loss of territory for Crossroads in 2010, however, this number will be able to go up, therefore justice gave to prevailing the Brook of the Plaza in the year of 2011. It had a reduction in the relative number of children in the first ages and the trend of growth of the group de20 a29 years. Characterizing a process of relative aging of the population: reducing in this way the population in the etria band of children with less than 01 year of age, which had to the high index of proven mortality for the lack of specialized medical assistance, and also is possible to mainly perceive economically considerable an active population in the group of people who vary de20 a39 years, beyond an expressive population of people with more than 50 years of age resulted of the increase of the life expectancy.