Análise do uso da terra e cobertura vegetal: relações com parâmetros de qualidade da água da bacia hidrográfica do igarapé do Cacau Pirêra, Iranduba-AM

Abstract

The studies focused on hydrographic basins have a significant importance in the social environmental scope, because they aim to understand how the actions of the society directly influence the natural environment. In this sense, water resources have always been indispensable for the development of societies, so it is important to study the social exploration of hydrographic basins. In this context, the hydrographic basins of the Cacau Pirêra area, located within the Metropolitan Region of Manaus, is used for the most diverse activities, from agriculture (economic activity) to tobathing (leisure). This research had as general objective analyze the chemical and physical parameters of the water, the land use and the vegetation cover in the Cacau Pirêra hydrographic basin, Iranduba-AM, as well as to map land use and vegetation cover in the hydrographic basin of the Cacau Pirêra; evaluate the surface waters of the hydrographic basin from the parameters of water quality: Transparency, Turbidity, Temperature, Electrical Conductivity, Dissolved Oxygen - OD, Hydrogenion Potential - pH and Total Dissolved Solids – TDS; identify which environmental changes may influence the parameters analyzed for water quality and map the spatial distribution of water quality parameters. The methodology consisted of procedures related to limnological data and the social appropriation of nature and its expressions in land use. Geotechnologies such as Remote Sensing (RS) and Geographic Information System (GIS) were used to achieve the established objectives. In addition, field work was carried out to collect water samples in loco during the flood season (May 12, 2018) and in the dry season (November 24, 2018). The water quality variables were related to Conama Resolution Nº. 357/2005. The turbidity data (6.60 ± 3.40 NTU), conductivity (9 ± 1.20 μS / cm) and TDS (4.38 ± 0.70 mg / L) allowed multiple uses during flooding. The temperature (> 31.5 ° C) and OD (> 6.5 mg / L) were higher in the dry season. The vegetation cover ranged from grasses to dense trees. In relation to uses, we mention the high number of housing estates, reflecting real speculation in the area and the presence of housing and agricultural areas in the interior of the hydrographic basin. Therefore, according to the analyzed variables, the basin water is not adequate for some uses disposed in the resolution, being restricted mainly to human consumption and primary contact.