Geotecnologias para análise da vulnerabilidade ambiental urbana da microbacia do Riacho do Gavião, Teresina (PI)

Abstract

The growing demand for space causes an irregularity and disorderly growth of cities, which can generate countless consequences, such as greater exploration of natural resources, increased deforestation, urban occupations in inadequate areas, among others. In this sense, the geotechnologies have made a great progress in the execution of environmental studies. The main objective of this work was evaluate the environmental vulnerability of the Riacho do Gavião basin in the municipality of Teresina of Piauí by using physical geotechnology tools and free softwares as QGIS and SPRING. The use of these softwares avoids the acquisition of license to access the tools of spatial data processing, and its is presented as a viable alternative in the elaboration of cartographic bases. The techniques used in the microbasin analysis were aimed at identifying areas of greatest environmental vulnerability, through soil use characteristics, slope, altimetric range and pedology. Allied to this concern, the uses of geotechnologies allow the detection and quantification of anthropic actions, enabling interventions and minimizing damages to the environment. With the Geographic Information Systems (GIS), it was possible to analyze the data obtained through the methodology used by Crepani et. al (2001). The results of the environmental vulnerability mapping of the Riacho do Gavião microbasin show that only 3% of the area according to the analysis is considered stable, 8% unstable, 35% moderately stable / unstable, and 54% moderately unstable. According to land use and occupation, 56.46% of the total area corresponds to built-up areas. In view of these results it is possible to measure the negative impact of soil occupation in these areas and the great importance of geotechnologies for this type of research.