Nota introdutória

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Methodologies for the assessment of climate change impacts on irrigated agriculture and irrigation systems

Doutoramento em Engenharia dos Biossistemas - Instituto Superior de AgronomiaThe different climate change scenarios forecast for Portugal an increase in air temperature associated with a reduction of the precipitation, which should implies a reduction in crop yields and a rise of water demand for irrigation. In this work a methodology was created, based on the development of software tools, with the objective of evaluating the impacts of climate change on irrigated agriculture. The proposed methodology consists in the combined use of a soil water balance model (IrrigRotation), geographic information systems and databases (IScenarios), spatial interpolation program (Interpolador) and a travelling gun irrigation systems design and evaluation model (Enrolador). This methodology was applied experimentally to two case studies in the Alentejo region. The results obtained for the climate change scenarios (2071-2100) showed an increase in seasonal irrigation requirements between 13% to 70% and an increase in peak irrigation requirements from 12% to 21%. It was also found an increase in the risk of crop failure for rainfed crops, with the value of water deficit ranging between 32% to 59%. The crops rotation was identified as an important adaptation tool