A cafeína é utilizada mundialmente como um traçador químico para identificar pressões antrópicas em recursos hídricos urbanos. No entanto, a sua quantificação demanda grandes investimentos financeiros. Este estudo tem como objetivo criar um modelo que determinaria, indiretamente, uma banda de possíveis concentrações de cafeína ao longo de um rio urbano, sem a necessidade de esforço laboratorial. O modelo se baseia na análise de correlação canônica, que é capaz de correlacionar dois conjuntos de variáveis, dependentes e independentes, de diferentes dimensões e gerar uma equação que resumiria a relação. Esta equação utiliza como entrada as concentrações de nitrogênio ammoniacal e ortofosfato, e como saída a população total, e habitantes em zonas irregulares, assim como a concentração de cafeína. A partir do modelo, foi possível elaborar uma banda de possíveis concentrações de cafeína ao longo do rio. Este modelo possui a capacidade de ser utilizado como uma ferramenta preliminar para gestores e pesquisadores.
Palavras-chave: análise de correlação canônica; cafeína; qualidade das águas superficiais
Caffeine is used worldwide as a chemical tracer to identify anthropic pressures on urban water resources. Nevertheless, its quantification demands great financial investments. This research created a model that would indirectly determine a range of possible caffeine concentrations along an urban river, without the need for extensive laboratory work. The model is based on Canonical Correlation Analysis (CCA), which can correlate two sets of different-sized independent and dependent variables in order to generate a single empirical equation. This equation takes as input the concentrations of ammonia nitrogen and orthophosphate, as well as the total population and the population inhabiting irregular housing areas. From the model’s results, it was possible to elaborate a spectrum of possible concentrations of caffeine along the Atuba River (Curitiba-Brazil). The tendency of water quality degradation of this river was also predicted. This model could become a useful preliminary analysis for water resource managers and researchers alike.
Keywords: caffeine; canonical correlation analysis; water quality modeling
Caffeine is used worldwide as a chemical tracer to identify anthropic pressures on urban water resources. Nevertheless, its quantification demands great financial investments. This research created a model that would indirectly determine a range of possible caffeine concentrations along an urban river, without the need for extensive laboratory work. The model is based on Canonical Correlation Analysis (CCA), which can correlate two sets of different-sized independent and dependent variables in order to generate a single empirical equation. This equation takes as input the concentrations of ammonia nitrogen and orthophosphate, as well as the total population and the population inhabiting irregular housing areas. From the model’s results, it was possible to elaborate a spectrum of possible concentrations of caffeine along the Atuba River (Curitiba-Brazil). The tendency of water quality degradation of this river was also predicted. This model could become a useful preliminary analysis for water resource managers and researchers alike.
Keywords: caffeine; canonical correlation analysis; water quality modeling
