Diagnóstico integrado da bacia hidrográfica do rio Jacu/PB-RN, Brasil: uso, ocupação e compartimentação Geoecológica

Abstract

Located in the Northeast Atlantic Hydrographic Region (NAHR), the Jacu River Hydrographic Basin (JRHB) occupies a total area of 2,842.5 km2, belonging to the states of Paraíba and Rio Grande do Norte. This interstate context has led to the JRHB not being included in an integrated manner, only partially, in the state reports on water resources; referring, specifically, to the parts that cover each state, which makes it impossible to know its potential, as well as, its limitations. Taking into account, the highlighted problems regarding the research area, this Mastering Dissertation has as its general objective to carry out an integrated diagnosis of the Jacu River Hydrographic Basin/PB-RN, Brazil; taking into account its forms of use and occupation, as well as, its natural support for the development of these human activities. Furthermore, this research has been developed based on the theoretical-methodological conception of Landscape Geoecology, which it has been systematized in the: organization and inventory phases, analysis, diagnosis, and proposal. In addition, the diagnosis of the JRHB has been carried out from two Geoecological perspectives: a) the historical-anthropogenic approach: where 18 classes of use and occupation were identified according to MapBiomas (2022), which were systematized according to level II of the SCUT (BIGS, 2013); and b) the structural approach: where it emphasizes the physical-geographic regionalization, which consists of the analysis and classification of the individual complexes of the Landscapes. Based on their morpho-sculptural domains, which correspond to their main geomorphological compartments, as well as, their forms of use and occupation, the geoecological units compartmentalized in the JRHB are: Planalto Cuités Unit (PCU); Bica Residual Massif Unit (BRMU); Piemonte Sertanejo Unit (PSU); Tabuleiro Canavieiro Unit (TCU), and the Planície of the Guaraíras and Aquiculture Unit (PGAU). Based on the data collected, the BHRJ has a total population of 177,038 inhabitants. In the agricultural sector, the production of temporary crops reaches approximately 929,031 tons, followed by 5,241 tons in permanent crops. In the raising of large, medium and small animals, the BHRJ has a quantity of 515,402 head. Regarding basic sanitation, the basin has an average of only 24% of its urban network with adequate sewage. Thus, according to its natural and socioeconomic aspects, the main potential of the basin is: Agriculture; Extractivism; Tourism; Ecotourism; Archaeology; Wind Energy Production; Mining; Civil Construction; Rainfall; Irrigation and Aquaculture. The main limitations are: Susceptibility to erosion; Water stress; Low water retention capacity; Soil salinization; Low soil fertility and risk of flooding of continental and coastal waters. In addition, the main environmental problems identified in the BHRJ were: Low sewage treatment rate; Deforestation of slopes; Soil erosion; Irregular occupation of river banks; Siltation; Pollution of water bodies. Therefore, these aspects guided the environmental planning proposals for the JRHB, in which, in total, 22 proposals are listed, 5 of which are general in nature, covering more comprehensive aspects. In summary, the others are distributed according to the basin zones, with the upper course having 6 proposals; the middle course having 7; and the lower course having 4.