Modelo metodológico de análise do processo de degradação ambiental e dos impactos na microbacia hidrográfica do Riacho Gravatá, Princesa Isabel-PB.

Abstract

Environmental degradation occurs through the conversion of natural systems into human ones through human action that modifies the environment. In this sense, the objective of this work was to analyze the process of environmental degradation and the impacts on urban watersheds in Princesa Isabel-PB. The methodology applied consisted of using the Multicriteria Analytical Method (AHP) to construct the Environmental Degradation Risk Map in the microbasin. The HAND Model was also used to map the areas susceptible to flooding in the urban area and in the microbasin. 45 questionnaires were also applied to residents and traders in the areas affected by the flooding. In addition, the Rapid Assessment Protocol (PAR) was applied in three different locations, namely the Padre Ibiapina, Maia and Macapá reservoirs, where visual observation of the areas and environmental problems was carried out. The results show that 50.8% and 17.7% of the microbasin areas have a very low and low risk of degradation. In the remaining areas, it was found that 0.04%, 2.25% and 29.21% had a moderate, high and very high risk of degradation, respectively. The very high risk of degradation occurs due to the expansion of agriculture and livestock farming and the replacement of vegetation by pastures and agricultural areas. Flooding and flash floods are present in different areas of the urban zone, and the rugged terrain of the area provides this situation. Regarding the environmental perception of residents and business owners, the vast majority are aware of the problems and causes of flooding and flash floods. The future areas prone to hydrological events are distributed in various locations of the microbasin, mainly vulnerable areas and areas of environmental risk. Regarding the degree of conservation of the points analyzed, the Padre Ibiapina reservoir was classified as having a very poor conservation status (E) with 27%, the Maia reservoir had 33% of its environmental condition classified as poor (D), and the Macapá reservoir had a good environmental condition (B), with 40%. These results show that microbasin area subject to environmental degradation and that the advancement of urbanization generates environmental impacts on water bodies, occupying areas of environmental preservation.