Mapeamento e análise da vulnerabilidade ambiental induzida pelo uso e ocupação do solo em uma unidade de planejamento hidrológico no semiárido brasileiro

Abstract

Environmental degradation is a global problem intensified by land use, without adoption of technical criteria, which besides promoting the loss of ecosystem functions and services essential to human survival, increases the vulnerability of the region. The effects of the substitution of native vegetation for anthropic uses, especially in riparian zones, are more aggravating in brazilian tropical semiarid regions, due to their natural characteristics that make it susceptible to degradation. In these regions the distinction between vulnerability conditioned by natural factors, that caused by anthropic factors, is less perceptible. So, the objective of this research was to map and evaluate the changes in the natural vulnerability and the physical and chemical attributes of the soil promoted by the land use in the Hydrological Planning Unit, where the Armando Ribeiro Gonçalves reservoir is inserted. The spatial evaluation of degrees of vulnerability was obtained from the integrated analysis of physical and environmental aspects, using geoprocessing. And the soil degradation was evaluated through the comparative analysis of the physical and chemical attributes of the soil under different uses, with reference to a soil under native vegetation. The results of this work indicate that the anthropic use promotes increased natural vulnerability and soil degradation. This problem can be further aggravated if there is an intensification of anthropic activities without the compatibility of supported uses and proper management of activities. The soil presented as one of the main responsible for the high natural and environmental vulnerability of the region, and its quality must be maintained to avoid degradation of terrestrial and aquatic systems. Therefore, this theme must be taken into account in policy and environmental decisions, so that environmentally vulnerable regions are effectively protected.