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Abstract(s)
Devido à crescente escassez de água, torna-se fundamental implementar práticas que permitam a gestão eficiente da água na agricultura. Este estudo teve como objetivo desenvolver uma base de dados (BD) georreferenciada com características dos sistemas culturais, do solo e clima, para dois aproveitamentos hidroagrícolas (AH), o AH do Vale do Sorraia e Paúl de Magos (AHVSPM) e o AH dos Minutos (AHM). Analisaram-se as necessidades de rega (NR) das três principais culturas: milho, tomate e sorgo.
Os dados meteorológicos foram obtidos de estações meteorológicas e de BD geoespacializadas (em grelha). Analisaram-se seis BD em grelha, concluindo-se que a reanálise AgERA5 (11 km x 11 km; 1979-2023) representava melhor as regiões em estudo, apresentando uma boa estimativa da evapotranspiração de referência (ETo). Contudo, a reanálise tende a subestimar a precipitação pelo que foi necessário realizar a correção do viés.
A determinação das NR foi realizada para as unidades homogéneas de análise utilizando os dados corrigidos AgERA5 e o software AquaCrop-OSPy. Os resultados mostram que o AHM apresenta NR líquidas (NLR) superiores ao AHVSPM, devido a diferenças climáticas e edáficas. No AHVSPM as NR foram de 430-827 mm para o milho, 412-777 mm para o sorgo e 417-667 mm para o tomate, enquanto no AHM foram de 576-933 mm, 507-711 mm e 518-787 mm, respetivamente para as mesmas culturas.
No AHVSPM, as necessidades de rega para o caso de seca extrema aumentam cerca de 9% (seca severa) e 11% (seca extrema), relativamente a um ano médio. No AHM as NR correspondem a um acréscimo de 7% (seca severa) e 10% (seca extrema) relativamente aos consumos médios.
Como principais limitações é de referir a falta de dados disponíveis para a parametrização do modelo AquaCrop-OSPy, que condicionaram a seleção das culturas e consequentemente a sua utilização.
Due to increasing water scarcity, it is essential to implement practices to promote efficient water management in agriculture. This study aimed to develop a georeferenced database (DB) with detailed information about farming systems, soil, and climate for two irrigation schemes: the Sorraia e Paúl de Magos Irrigation Scheme (AHVSPM) and the Minutos Irrigation Scheme (AHM). The irrigation requirements (IR) of the three main crops- maize, tomato and sorghum- were determined. Meteorological data were collected from weather stations and gridded datasets (DS). Six gridded DS were analyzed, concluding that AgERA5 reanalysis (11 km x 11 km; 1979-2023) provided the most accurate representation of the study areas, providing a reliable estimation of the reference evapotranspiration (ETo). However, the reanalysis tends to underestimate precipitation, requiring bias correction. The determination of IR were carried out for the homogeneous analysis units using adjusted AgERA5 data and the AquaCrop-OSPy software. The results show that AHM has higher net irrigation requirements (NIR) than AHVSPM, due to climatic and soil differences. The IR ranged from 430-827 mm for maize, 412-777 mm for sorghum, and 417-667 mm for tomato in AHVSPM, while in AHM, they ranged from 576-933 mm, 507-711 mm, and 518-787 mm, respectively. In the AHVSPM, irrigation requirements in the case of extreme drought increase by approximately 9% (severe drought) and 11% (extreme drought) compared to an average year. In the AHM, irrigation requirements correspond to an increase of 7% (severe drought) and 10% (extreme drought) relative to average consumption. The main limitation should be highlighted as the lack of available data for the parameterization of the AquaCrop-OSPy model, which constrained the selection of crops and, consequently, its application.
Due to increasing water scarcity, it is essential to implement practices to promote efficient water management in agriculture. This study aimed to develop a georeferenced database (DB) with detailed information about farming systems, soil, and climate for two irrigation schemes: the Sorraia e Paúl de Magos Irrigation Scheme (AHVSPM) and the Minutos Irrigation Scheme (AHM). The irrigation requirements (IR) of the three main crops- maize, tomato and sorghum- were determined. Meteorological data were collected from weather stations and gridded datasets (DS). Six gridded DS were analyzed, concluding that AgERA5 reanalysis (11 km x 11 km; 1979-2023) provided the most accurate representation of the study areas, providing a reliable estimation of the reference evapotranspiration (ETo). However, the reanalysis tends to underestimate precipitation, requiring bias correction. The determination of IR were carried out for the homogeneous analysis units using adjusted AgERA5 data and the AquaCrop-OSPy software. The results show that AHM has higher net irrigation requirements (NIR) than AHVSPM, due to climatic and soil differences. The IR ranged from 430-827 mm for maize, 412-777 mm for sorghum, and 417-667 mm for tomato in AHVSPM, while in AHM, they ranged from 576-933 mm, 507-711 mm, and 518-787 mm, respectively. In the AHVSPM, irrigation requirements in the case of extreme drought increase by approximately 9% (severe drought) and 11% (extreme drought) compared to an average year. In the AHM, irrigation requirements correspond to an increase of 7% (severe drought) and 10% (extreme drought) relative to average consumption. The main limitation should be highlighted as the lack of available data for the parameterization of the AquaCrop-OSPy model, which constrained the selection of crops and, consequently, its application.
Description
Mestrado em Engenharia Agronómica / Instituto Superior de Agronomia, Universidade de Lisboa
Keywords
sistema de informação geográfica aproveitamento hidroagrícola regadio AgERA5 variabilidade climática geographic information system irrigation Scheme irrigated agriculture climate variability
Pedagogical Context
Citation
Almeida, M.E.S.T. Determinação e espacialização das necessidades de rega com base em dados climáticos em grelha. Lisboa: ISA, 2024, 120 p. Dissertação de Mestrado
Publisher
Instituto Superior de Agronomia, Universidade de Lisboa