Análise integrada da vulnerabilidade erosiva da bacia hidrográfica do Rio Duas Bocas (ES)

• Autor(a) principal: Santos, James Rafael Ulisses dos
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/9322
• topic: Ecology of landscapes; Erosion; Watersheds; Geografia; Ecologia das paisagens; Erosão; Bacias hidrográficas; 91

This study aims to analyze the erosive vulnerability of the river Duas Bocas basin, located amid the municipalities of Santa Leopoldina and Cariacica, Espírito Santo state - Brazil, through an integrated landscape analysis. The integrated analysis considered the natural and human elements that make up the landscape, namely: slope, soils, land use and cover and rainfall. The objectives were to check the changes in land use and cover in the years 1970, 2008 and 2012 and the erosive vulnerability in the years 1970, 2008, 2012 and 2013, which resulted in changes in the landscape. The methodology consisted of bibliographical research on the subject and acquisition of cartographic data (such as photographs, aerial images, vector and raster data). The method adopted for modeling the erosive vulnerability was the environmental fragility proposed by Ross (1994) and Amaral & Ross (2009), based on the concept of ecodynamics by Tricart (1977). It was found that the Native Forest class of land use and cover has gradually grown from 1970 to 2012, due mainly to the regeneration in areas previously occupied by Macega (undergrowth) and grazing areas – this regeneration was mainly in the area bounded by REBIO (Biological Reservation) Duas Bocas. The Banana farming class had a slight increase, occurring mainly in the central part of the study area. The Urban Area had a small increase in its percentage due to the city growth process occurring outside the perimeter of the basin. The years 1970 and 2008 showed a prevalence of erosive vulnerability classes of low and very low downstream, and medium and high classes at the central and upstream sectors. In 2012 the lower and middle classes stood out downstream, with middle and high classes prevailing in the central portion and medium class at the upstream. On the other hand, 2013 was the year that had the highest percentage of medium and high vulnerability, except for the downstream sector, comprising the fluvial plain, which showed low vulnerability. Thus, it was found that with the cross-evaluation of slope, soils, use and land cover and rain variables was possible to determine the changes that occur in the basin, with the percentage of erosive vulnerability.