Análise da eficiência da várzea do ribeirão Parelheiros na melhoria de qualidade das águas que afluem à represa do Guarapiranga, São Paulo / Analysis of the performance of the wetlands of the Parelheiros creek in the improvement of the quality of the waters before they enter the Guarapiranga reservoir, São Paulo

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The wetlands formed by Parelheiros creek were the focal point of this study. The creek is a water body that receives waters imported from Billings reservoir into Guarapiranga reservoir. The referred creek and associated wetlands also receive waters with diffuse source pollutants from inside and outside of the Guarapiranga watershed. This applied research work aimed at analyzing the performance of the referred wetlands in the improvement of the quality of the above-mentioned waters before they enter the Guarapiranga reservoir. Water quality data regarding several relevant parameters (monthly averages of total and fecal coliform counts, total cyanobacteria cell counts, exotoxin concentrations, total nitrogen and total phosphorus, apparent color, turbidity, chemical oxygen demand and pH) as well as flow data (minimum, average and maximum influent flows) were analyzed. The data were collected during a ten-month period comprised of four dry weather months followed by six wet weather months. It was not possible to analyze completely the effects of flow regime on the performance of the wetlands as a buffer zone for pollutant abatement because there was no available data on the diffuse source contributions, since they are not monitored. The wetlands showed removal efficiencies above 30% with respect to the improvement of some (not all) variables, as follows: turbidity, total cyanobacteria concentration and microcystia concentration. The pluviometry exerted significant influence on the wetland performance as a buffer zone for abatement of certain water constituents which represent pollution. However, removal efficiencies regarding wet and dry periods were very similar to each other

ASSUNTO(S)

guarapiranga swampy áreas alagadas (várzea) macrófitas aquáticas water (quality) wetlands wetlands guarapiranga água (qualidade) aquatic macrophites

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