Qualidade ambiental da bacia hidrográfica do rio Piancó Piranhas sob análise multicriterial.

Abstract

The objective of this work is to analyze the environmental quality of Piranhas hydrographic river basin, by proposing a model of multi-criteria analysis, with emphasis on sub - basins of the river Peixe, Piancó and Alto Piranhas. The model was constructed based on an integrated environmental analysis of the area , gathering socioeconomic aspects ( Density , GDP and HDI ) , environmental aspects ( Land use and presence of green areas ) and water quality analysis ( IQA ) , seeking to identify the effects of environmental impacts of human activities on water resources of the basin . The aspects analyzed were processed and integrated with the use of GIS sig gV 1:12 final version. Thematic maps of the most relevant aspects for multicriteria analysis were made. The issues were prioritized: Density Pattern of Use and Land cover and presence of green areas in the basin, the crossing of this information allowed the construction of the Thematic Map Identification of Critical Areas for the study area, where the recognition was possible considered environmentally critical areas. The Very Critical areas are mainly located in the Fish River sub -basin, these areas should be given priority when planning the implementation of plans and intervention programs aimed at reducing the sources of pressure. During the observation period, the IQA ranged between fair and good, it was found that there was a decrease in the IQA with increasing flow rate, markedly related to the first rainfall events. With this, it became evident that the water resources of the Piranhas River basin has suffered with anthropic pressure observed inside.