Diagnóstico físico-conservacionista, socioeconômico e ambiental em microbacia hidrográfica no Seridó Paraibano.

Abstract

The application of diagnoses that subsidize the correct planning of natural resources in catchment areas of the northeastern semiarid, is of extreme importance for the recovery of these ecosystems, which are suffering from the degradation caused by the exploration model applied since its colonization. The aim of this study was to perform the physical conservationist diagnosis complemented by adaptation in the use of the land in accordance with Federal Law Nº 12,651, May 25, 2012 on the watershed of the Saco River, on the city of Santa Luzia, located in the semiarid region of the state of Paraíba; and estimate the socioeconomic and environmental degradation in the communities of the Saco and Pinga, inserted in the same watershed. The study area is limited between geographical coordinates: 36° 52 ' 14 "to 36° 56 ' 44" West longitude and 6° 53 ' 01 "the 7° 03 ' 23" North latitude. The methodology used for application of the physical-conservationist diagnosis was the one that uses the Roughness Coefficient (Ruggdeness Number - RN) to classify the potential use of the lands; and being supplemented by the division of each compartment in Alternative Soil Use Areas (ASUA), Legal Reserve (LR), Areas of Restricted Use (ARU) and Permanent Preservation Areas (PPA), according to the Federal Law Nº. 12,651, May 25, 2012; and identification of possible conflicts in land use for each division. The survey of socioeconomic and environmental data was obtained from sampling, from nucleus at family level, by applying structured questionnaires, which raised the social, economic, technological and environmental factors of the population, subdivided into variables and identified by codes.To evaluate the data we used the most frequent values (mode), maxima and minima of each variable, which were introduced in the straight line equation determined for each case, to calculate the percentages of social, economic, technological, environmental and socioeconomic degradation. In the ASUA, there is a greater aptitude for grazing/silvipastoris systems (compartments III, V, IX and X); the minimum occupation of native vegetation was 54.0% between the compartments, not being necessary forest reforestation of the LR for none of them. In ARU, 2.12 ha of pasture and 5.1 ha mining are not in accordance with the legislation. The main conflicting areas in the PPA occurred in compartments I (43.9 ha) and II (47.1ha). The degree of socioeconomic degradation was 53.3% in the community of Saco and of 54.9% in Pinga. The environmental degradation was approximately 34.8% for the community of Saco and 13.0% for the Pinga. Dividing each compartment according to the methodology we used, it was possible to, besides indicating the proposed use by RN, apply simultaneously environmental legislation in watershed management. Levels of socioeconomic and environmental degradation found for the two communities were higher than the limit recommended by the methodology applied, signaling that it is needed urgent solutions to prevent its advance and mitigate its negative impacts on the local population