A simplified equation to estimate spatial reference evapotranspiration (ETo_Ts) from remote sensing-based surface temperature (Ts) and local standard meteorological data is suggested. It is based on a parameterization of the meteorological conditions of the first few meters of the atmosphere through two parameters (a and b) which come from a simpler form of the Penman–Monteith equation:

from the mathematical point of view, the fao penman-monteith equation shows a homographic function related to the wind speed. the homographic function has horizontal and vertical asymptotes. in this issue horizontal asymptote is applicable; because the vertical asymptote occurs for negative values of wind speed but the negative sign indicates the direction of the wind speed and only the absolut...

ABSTRACT-Different evapotranspiration (ET) estimation equations having different accuracy with different conditions have been developed for ET estimation. This study will firstly focus on the estimation of 13 climatic equations of daily garlic ET estimation whose  ET is measured by lysimeter to provide information which can be helpful in selecting an appropriate ET equation. The paper aims at s...

abstract-different evapotranspiration (et) estimation equations having different accuracy with different conditions have been developed for et estimation. this study will firstly focus on the estimation of 13 climatic equations of daily garlic et estimation whose  et is measured by lysimeter to provide information which can be helpful in selecting an appropriate et equation. the paper aims at s...

Daily evapotranspiration (ET) rates are needed for irrigation scheduling. Owing to the difficulty of obtaining accurate field measurements, ET rates are commonly estimated from weather parameters. A few empirical or semi–empirical methods have been developed for assessing daily reference crop ET, which is converted to actual crop ET using crop coefficients. The FAO Penman–Monteith method, which...

The proposed method for calculation of potential evapotranspiration is Penman-Monteith FAO method, but there are other methods that require less meteorological data but estimates close to the FAO Penman-Monteith method in different climatic conditions.  Performance evaluation of these methods on the same basis is prerequisite for selecting an alternative approach in accordance with available da...

Wheat is an important crop of India. Precise estimates of evapotranspiration can be obtained by multiplying crop coefficients to reference evapotranspiration using readily available climatic data. PenmanMonteith equation is adopted world wide as the most reliable and accurate method for computing reference evapotranspiration. The Food and Agriculture Organization (FAO) presented crop coefficien...

We present an approach for the calibration of simplified evaporation model parameters based on optimization against most complex estimation, i.e., Penman–Monteith equation. This computes from several input quantities, such as air temperature, wind speed, heat storage, net radiation etc. However, sometimes all these values are not available, therefore we must use models. Our interest in free wat...

Evaporation is a fundamental parameter in the hydrological cycle. This study examines the performance of M5model tree and artificial neural network (ANN) models in estimating potential evapotranspiration calculated byPenman- Monteith and Hargreaves- Samani equations. Daily weather data from two meteorological stations in asemi-arid climate of Iran, namely Kerman and Zahedan, were collected duri...