Water Allocation and Resources Management Using a Hydro-Economic Optimization Model: The Case Study of the Sub-Middle São Francisco Watershed

The Northeastern semiarid region of Brazil is known of its irregular rainfalls and water scarcity. Reservoirs and perennialized rivers are the only water source in the dry season. Water disponibility is limited, already causing several conflicts between different water users and uses, like hydropower, irrigation, human consumption, animal consumption, industrial and aquaculture. Furthermore efforts are taken to exploit this region economically with some irrigation sites using mainly crops with a high water need and high drought sensitivity, like sugar cane. Conflicts can get even more challenging with the Integration Project of the San Francisco River (PISF), where two lines of water channels are being built to deliver water to the north and the northeast of the region. Water allocation rules and decision making based on land use change and climate change becomes more important. The aim of the research, linked with the INNOVATE project, is the development of a hydro economic model which uses optimization algorithms to determine the hydro-economical optimum for water allocation in the middle São Francisco River Basin. The hydro-economic optimization model is written in GAMS. Expected results are optimal water storage in reservoirs and allocation rules for irrigated production under different scenarios of water transfers, land use and climate changes.