FALCÃO, E. C.; http://lattes.cnpq.br/8969174747757142; FALCÃO, Ermano Cavalcante.
Résumé:
The exploitation of the Caatinga biome occurred in a predatory way over the years.
Degrading factors like deforestation and fires, in association with the improper use of
the soil and unfavorable climatic conditions, have caused biodiversity reduction in the
semiarid region of northeastern Brazil, with consequent degradation of its lands. The
complexity of the variables involved in natural environments has motivated the
scientific community to search for solutions for planning the use and management of
their resources, through an integrated approach. The current study aimed to map and
analyze the areas with different levels of risk to the environmental degradation
process in the hydrographic basin of the Juá dam, which is situated in the
municipality of Boa Vista, in the semiarid region of the state of Paraíba. As to the
methodology, multi-criteria analysis was performed with support of geotechnologies
such remote sensing images (TM/LANDSAT-5 and SRTM) and the free software of
geographic information system (GIS), the SPRING system. Relative criteria or factors
(soil occupation, soil type, declivity and dwelling) and restrictive (water bodies) were
used in the analysis process. Weighted relative importance among criteria was
fulfilled by a team of experts in the field of this research by using the Analytic
Hierarchy Process (AHP) method. For multiple-criteria aggregation (MCA), the
weighted linear combination (WLC) was used which generated the map with spatial
distribution of risk levels to the environmental degradation process. Results show that
the class of very low risk level is distributed in 10,02% of the total area of the studied
basin while the class of low risk level is distributed in 35,57%. The class of medium
risk level presents the largest area in the basin occupying 45,07% of its lands. The
class of high risk level is distributed in 3.64% of the basin area. The class of very
high risk level occupies 4.21% of that area, being distributed mainly in the sectors of
bentonite extraction. The north region and part of the southwest region of the basin
constitute the areas with the highest risk levels to the environment degradation, while
the southeast region includes the areas with the lowest risk levels to this process.