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Hargreaves and other reduced-set methods for calculating evapotranspiration

Globally, irrigation is the main user of fresh water, and with the growing scarcity of this essential natural resource, it is becoming increasingly important to maximize efficiency of water usage. This implies proper management of irrigation and control of application depths in order to apply water effectively according to crop needs. Daily calculation of the Reference Potential Evapotranspiration (ETo) is an i...

Hargreaves and other reduced-set methods for calculating evapotranspiration

This edition of Evapotranspiration - Remote Sensing and Modeling contains 23 chapters related to the modeling and simulation of evapotranspiration (ET) and remote sensing-based energy balance determination of ET. These areas are at the forefront of technologies that quantify the highly spatial ET from the Earth's surface. The topics describe mechanics of ET simulation from partially vegetated surfaces and stoma...

Hargreaves and other reduced-set methods for calculating evapotranspiration

Globally, irrigation is the main user of fresh water, and with the growing scarcity of this essential natural resource, it is becoming increasingly important to maximize efficiency of water usage. This implies proper management of irrigation and control of application depths in order to apply water effectively according to crop needs. Daily calculation of the Reference Potential Evapotranspiration (ETo) is an i...

Water scarcity and drought : setting the stage

Apresentação efectuada no "Douro River Basin UNESCO IHP-HELP – International HELP Symposium on River Basin Level Responses to Water Scarcity and Drought under Uncertain Climate Futures”, em Mirandela, Portugal, 2010 ; Douro River Basin is under pressure because of various external drivers, such as climate change. Its water resources is much stressed, particularly in the Tras-os-Montes, near Spain and the Spani...

Escassez de água e seca na bacia hidrográficado Rio Sôrdo

A escassez de água e seca é um fenómeno característico do nosso país, com intensidade e efeitos variáveis no espaço e no tempo. A situação geográfica do território de Portugal é favorável à ocorrência de episódios de seca e deve ser encarado como um "elemento climático de determinada frequência". A bacia hidrográfica do Rio Sôrdo, alvo deste estudo, constitui a nível regional uma das grandes reservas de água p...

Drip Irrigation using a PLC based Adaptive Irrigation System

Irrigation is presently the main user of world´s fresh water. Most of it goes to irrigating small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. The dramatic development of Programmable Logic Controllers, PLCs, and their rather affordable price has made it possible to use them as stand-alone irrigation controllers. In this paper a PLC is used to adapt the...

Drip irrigation using a PLC based adaptive irrigation system

Water saving with a PLC based adaptive irrigation system

Irrigation is presently the main user of world´s fresh water. Most of it goes to irrigating small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. The dramatic development of Programmable Logic Controllers, PLCs, and their rather affordable price has made it possible to use them as stand-alone irrigation controllers. In this paper a PLC is used to adapt ...

Modelo de apoio à decisão para a gestão de bacias hidrográficas usando Mike Basin

O aumento da procura dos recursos hídricos, a limitação da oferta destes recursos, tem sido uma preocupação constante para a sociedade actual. O aumento da complexidade na gestão dos recursos e a dificuldade de resposta às necessidades da procura fazem com que seja urgente a utilização de novas metodologias e tecnologias, de modo a poder criar modelos de previsão de cenários futuros. Com base neste contexto é f...

Pressões antropogénicas nas bacias hidrográficas dos Rios Sôrdo, Pinhão e Ribei...

A área estudada situa-se nas bacias hidrográficas dos rios Sôrdo, Pinhão e Ribeira de Vila Chã, abrangendo estes três rios e seus afluentes, no sentido de estudar todo o tipo de pressões antropogénicas exercidas ao longo destas bacias. Este trabalho compreende a revisão bibliográfica e descrição detalhada das ferramentas a utilizar no desenvolvimento de uma metodologia, que, abordará sequencialmente, as seguin...