Surface water resources quality at watersheds of the Alto Rio Grande region, MG State / Qualidade dos recursos hÃdricos superficiais em sub-bacias hidrogrÃficas da regiÃo Alto Rio Grande

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Water resources, essential element to life, have been serious modified in last years, basically by human actions. Water quality studies have been very important to environmental management. This work aims at to study the behavior of surface water resources quality, in three specific environments belong to âWater Resources Unit for Planning and Managementâ GD 1, in Alto Rio Grande region, MG State. One of the watersheds monitored drainages area of 687 ha and it is nominated RibeirÃo Lavrinha, being direct affluent of Rio Grande River, enclosed to Mantiqueira Mountains. Another watershed monitored drainages area of 178 ha and it is nominated RibeirÃo Vista Bela, flowing direct to Aiuruoca River, in Campos das Vertentes sub-region. The third watershed is nominated RibeirÃo Marcela and drainages area of 477 ha, being affluent of Jaguara River, which it flows direct to Hydropower Plant Camargos Reservoir/CEMIG. This watershed is also located at to Campos das Vertentes sub-region. In first watershed, the samples were collected in six locations; in second and third, in four locations. Land use map of each watershed was developed using GPS based on field observations. It was monitored, from May/06 to January/07, the following parameters: hydrogen potential (pH), Dissolved Oxigen (OD), electric conductivity (CE), salinity, temperature, Oxygen Biochemistry Demand (DBO), Oxygen Chemistry Demand (DQO), nitrate (NO3-), ammonia (NH3), phosphorous (PO4), turbidly, total soil, total dissolved soil (TDS), fecal coliform (Escherichia coli), total coliform. Water Quality Index (IQA), proposed by âMinas Gerais State Institute for Water Resources Managementâ (IGAM), was calculated for all samples. In addition, water bodies were classified in quality class according to CONAMA Resolution 357/05. The ambient conditions had in such a way reflected in the values of the IQA how much in the framing process, identifying itself clear difference of the Lavrinha watershed in relation to excessively, being the presence of areas with native bush, the determinative factor of this situation. Which was evidenced despite the main .causing factor of the critical picture is the NMP of coliform, if associates with the milk productions. In lesser the scales, the OD and the DBO are also limits factors, and, of well evident form it associates presence of PO4 to the culture of maize in the sub-basin of the Marcela.

ASSUNTO(S)

water resources water quality engenharia de agua e solo watersheds qualidade da Ãgua recursos hÃdricos bacias hidrogrÃficas

ACESSO AO ARTIGO

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