Environmental Fragility of Land Systems in a Hydrographic Basin Located in the South Region of the State of Bahia, Brazil

Abstract

The drainage system of a hydrographic basin is formed by integrated functional systems, which provide ideal conditions for studies aimed at conserving and preserving ecosystems. Given the need to protect remnants of native vegetation in the Atlantic Forest, this study identified the terrain systems of Una River Basin (BHRU), Bahia, through the technical application of terrain assessment and multi-criteria methodological approach. In addition, the identified systems were evaluated for their levels of potential and emerging frailty. The results showed that the BHRU is subdivided into 8 (eight) terrain systems. Considering the relationship between the natural dynamics of the environment and the pressures exerted by anthropogenic activities, it was found that alluvial and coastal systems have areas with high degree of emerging fragility (8.20% of the BHRU). This high degree of emerging fragility is due to its natural characteristics, allied to the increase of anthropized environments that contrast the Buerarema and pre-coast systems, which have more excellent environmental protection due to extensive vegetation cover on their slopes. The study's methodology was shown to be adequate for the identification and characterization of terrain systems in the BHRU and can be replicated in other ecoregions in the country.