Analysis of the waters uses of Paraiba River basin with the integration project of Rio São Francisco, east axis, by the multiobjective optimization

Abstract

This work evaluates superficial water uses in the Paraíba River considering the São Francisco River Integration Project – PISF. Four system´s operation scenarios were considered: C1- considering the current form of the PISF flow transportation (through the river bed), C2- considering part of the flow being transported by pipelines to the water treatment plant of Gravatá, C3 and C4- considering the aforementioned scenarios with and without the water use restrictions established by the 87-th Joint Resolution of the Agência Nacional de Águas - ANA and Agência Executiva de Gestão de Águas da Paraíba- AESA. A multiobjective optimization model, based on sucessive linear programming, was used when considering the period of time from 2012 to 2017, which was marked by severe drought in the region. The system performance was evaluated through the use of indicators related to the meeting water demands and the efficiency of reservoirs. The water losses in river bed and by evaporation in the reservoirs along the Paraíba River were calculate as well as to estimated the financial cost of these losses. The results show that the scenarios considering pipelines would be more efficient, either regarding to the water demand supply or in minimizing water losses. The limits established by the 87-th Joint Resolution limit the efficiency of water uses of the system, so that the use of water without the limits established by the Resolution does not affect priority water use neither the reservoirs performance.