Alocação quali-quantitativa de águas em bacias hidrográficas: metodologia multiobjetivo inserida no contexto da gestão dos recursos hídricos

Abstract

In Brazil, water rights grant criteria are very restrictive, causing discontent among users and generating conflicts, mainly in several water basins, where the total water demands exceed the maximum legal volume. The traditional water allocation, based only on quantitative criteria, is no longer enough. It is necessary to consider multiple and conflictive objectives, the stochastic behavior of hydrologic data, and associated uncertainties, which makes the water allocation models increasingly complex. This paper presents an allocation methodology of surplus water availability in a watershed, considering multiple objectives and constraints, multiple users and also easy adaptability to use with other models and rationing scenarios (zero or negative surplus discharge). Thus a methodology is proposed for optimizing the allocation of surplus discharge in a basin through a multiobjective evolutionary algorithm in which adaptations and reproduction operators were inserted to incorporate the specific constraints of the problem and overcome the obstacles presented. The methodology was evaluated in the Gramame river basin and the analysis included two hypothetical scenarios of probabilistic forecasts of precipitation: one above-normal forecast and one below-normal forecast. The results show that the algorithm proved to be adequate, because there was convergence for the most feasible regions of Pareto Front.