The security of the different water uses, environmental services and ecological balance depends upon a well-weighted combination between quantitative and qualitative aspects in rivers. This research describes applications of a new approach of the frequency curves for discharge, which were associated with frequency curves for water quality. Data on total phosphorus (2005 to 2009) and monthly average flow (1959 to 2003) from the Paraíba do Sul and Sorocaba Rivers were compiled to further illustrate the concept. The integration between the curves of water quantity and quality was considered desirable as it can aid in the planning of water concessions, charging for water uses, environmental monitoring and establishment of water quality standards and framework. Moreover, these curves can accommodate variations in climate and land use, allowing the establishment of environmental scenarios
cumulative frequency curves; legal framework for water bodies; water resources management; rivers; environmental services
