Simulação da operação e estimativa dos benefícios socioeconômicos do reservatório Coremas/Mãe d'Água sujeito a múltiplos usos.

Abstract

Reservoir operation involves allocating available water among multiple uses and users, minimizing the risks of water shortages and flooding and maximizing the beneficial use. Simulation models associated with reservoir operation provide higher flexibilty in detailed and more realistic representation of complex configuration such as the two interconnected reservoirs, Coremas and Mae D'agua, object of study in this work. This system is located in the semi-arid region of Paraiba state, which is located in the northeast part of Brazil. Two rivers flow into, Pianco and Emas rivers, and the one river flows out, Pianco river, the Coremas reservoir and one river flow into , Aguiar river , the Mae D'agua reservoir. A irrigation channel of 57 Km is being constructed to divert from the Mae D'agua reservoir a discharge up to 4 m3 / s to an irrigation area located in the neighbourhood of the city of Sousa. Moreover, the reservoir waters are used to supply human consumption of the cities of Pianco, Coremas and, in the near future, Patos, to regulate the downstream outflow, to generate eletric power energy, to irrigate and grow crops in lands located around the reservoir, to maintain or improve the reservoirs fishing activities, and so on. The mathematical model developed herein and coded for the MATLAB software to simulate the physical behavior of this two interconnected reservoirs is based on the monthly mass balance equation that track the movement of water was based on historic observed data. This model was used to study the system's behavior taking into account the historic observed data. This model was used to study the system's behavior taking into account several scenaries including rainy, normal and dry years, reservoir initial conditions and upstreams interventions. The results have shown that any upstream intervention or long drought season that reduces the water inflow in more than 20 % compromises the sustainability of the reservoir. Economic and social analysis has also been performed in order to evaluate the benefits of the water use in terms of agricultural and fishing activities'profits and number of jobs provided along with the estimated dairy incomes.