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Blaney–Criddle Equation
The Blaney–Criddle equation (named after H. F. Blaney and W. D. Criddle) is a method for estimating reference crop evapotranspiration. Usage The Blaney–Criddle equation is a relatively simplistic method for calculating evapotranspiration. When sufficient meteorological data is available the Penman–Monteith equation is usually preferred. However, the Blaney–Criddle equation is ideal when only air-temperature datasets are available for a site. Given the coarse accuracy of the Blaney–Criddle equation, it is recommended that it be used to calculate evapotranspiration for periods of one month or greater. The equation calculates evapotranspiration for a 'reference crop', which is taken as actively growing green grass of 8–15 cm height. Equation ''ETo'' = ''p'' ·(0.457·''Tmean'' + 8.128) Where: ''ETo'' is the reference evapotranspiration m day−1(monthly) ''Tmean'' is the mean daily temperature °Cgiven as ''Tmean = (Tmax + Tmin )/ 2'' ''p'' is the mean da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evapotranspiration
Evapotranspiration (ET) is the combined processes by which water moves from the earth’s surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpiration (movement of water from the soil, through roots and bodies of vegetation, on leaves and then into the air). Evapotranspiration is an important part of the local water cycle and climate, as well as measurement of it plays a key role in agricultural irrigation and water resource management. Definition Evapotranspiration is a combination of evaporation and transpiration, measured in order to better understand crop water requirements, irrigation scheduling, and watershed management. The two key components of evapotranspiration are: * Evaporation: the movement of water directly to the air from sources such as the soil and water bodies. It can be affected by factors including heat, humidity, and wind speed. * Transpiration: the move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
