QUALITY MAPPING OF SHALLOW GROUNDWATER THROUGH PHYSICAL-CHEMICAL INDEX IN CAMPOS DOS GOYTACAZES

Abstract

The increasing production and inadequate control of solid waste in urban areas indicate a risk of groundwater contamination, thus motivating numerous discussions in the scientific community about the mechanisms of monitoring water in the subsurface. In this context, it is appropriate to use methodologies that seek to synthesize information from various parameters into a single value, offering safety and practicality in the diagnosis of the quality of the groundwater. Thus, the research proposes to evaluate the quality of shallow groundwater throughout the extension of the municipality of Campos dos Goytacazes in the years 2013, 2014 and 2015 through the physical-chemical index IQAFis, aiming to establish correlations with aspects of urbanization in this dynamic. For this, we initially selected the indicators to compose the physical-chemical quality index (IQAFis). Next, we catalogued the laboratory analyses of water samples from 164 wells between 8 and 10m deep. Then, we calculated the IQAFis for each well. Subsequently, we performed the spatialization of the data with the elaboration of two maps containing, in each one, the auxiliary map focusing on the central sector of the municipality. The diagnostic picture reveals the existence of socio-environmental interaction harmful to the underground water resources, in a way that in the proximities of urban constructions the places where the water table is totally preserved are rare. Since this is an area of multiple uses, such as residential, agricultural, and commercial, it ends up exposing the region to greater risks of contamination. It is noteworthy that, as verified in field work, the region has potential polluting agents, leading to a greater number of contaminants that can be released into this environment. The study is based on Ordinance 2914/2011 of the Ministry of Health resolution and resolutions 357 and 396/08 of the National Council on the Environment, the results obtained reveal a picture of changes in the metal elements of shallow groundwater, especially in central areas where we have a large population concentration, not being recommended for use for human consumption without the proper treatment processes. The present article is configured in a valuable research method, either punctual or spatial, for the identification of the characteristic patterns of water quality. The established methodology presented satisfactory results in the environmental diagnosis, either in a punctual or even regional scale, being able to collaborate in the actions of shallow groundwater management in urban environments.