Climate and land use change impacts on the water-energy-food nexus in the arid northeast of Brazil – scenario analysis and adaptation options

Within the German-Brazilian project INNOVATE the interactions of hydrology, water resources management, land use, climate variability and climate change in the São Francisco river basin (Northeast Brazil, catchment area approximatley 640 000 km2) are analysed with a focus on the Itaparica reservoir in the Sub-Medio São Francisco. The accumulation of major drought events in the northeast of Brazil over the last years serves as a reminder to decision makers and water management executives that this is a peak peril. It may become more damaging and prevalent as climate patterns change. Impacts of land use change (e.g. further increase of irrigated agriculture already responsible for approximately 80 % of water withdrawals) on water availability, water quality and food production are another major concern. In order to define sustainable management strategies for the water and land resources in the river basin, integration of different water-using sectors and actors is needed, considering upstream-downstream and other user conflicts. In our presentation we will show how water resources and water quality will develop under different climate and land use scenarios, using a chain of simulation models driven by global climate and land use scenarios. Quantitative hydrology and water resources management (reservoir regulation, hydropower production, withdrawals for irrigation and other water users), water quality and (changing) land use pattern are integrated for the whole river basin. These results are used in follow-up analyses, e.g. reservoir dynamics (2-D; 3-D) for the Itaparica reservoir and an optimization model for water resources allocation in the Sub-Medio São Francisco.