Conservation status and water quality in a periurban watershed in Central Amazon

Abstract

Forested basins are generally associated with better water quality, compared to anthropogenic uses. However, the multiplicity of variables and interactions makes this relationship quite complex, especially in the Amazon, where water systems are inter-influential. We classified the land use and cover and the conservation status of the Tarumã-Açu Basin, in Central Amazon, as well as to analyze its correlation with the physical-chemical parameters (temperature, pH, electrical conductivity, oxygen dissolved, total dissolved solids and turbidity) of water quality at preserved and altered sites. The values ​​were also compared with CONAMA Resolution 357/2005 and with environmental factors (quota and rainfall). The results showed a very fragmented basin and regular degradation status, despite its predominantly forest cover. We found good water quality, compatible with Class 2 normative parameters, although for the areas of anthropic influence the reduction of the quota and the capacity for self-purification reduces the quality. There was no linearity relationship between the parameters evaluated and the conservation status of the basin, suggesting the existence of more rupture factors in this relationship. Thus, it is necessary and challenging for managers to know holistically the eco-hydrological dynamics of the basin and integrate it with policies and plans.