نتایج جستجو برای: standard evapotranspiration

تعداد نتایج: 523781  

Journal: :آب و خاک 0
شریفان شریفان علیزاده علیزاده

abstract in order to estimate the reference evapotranspiration different equation is used. validity of each methods depends upon the climate and the parameters which are used in these equations. therefore it is necessary to calibrate these methods for any specific area and for any desired frequency. in this study common temperature and radiation based methods were used for calculating crop evap...

2012
Ketema Tilahun Zeleke Leonard John Wade

The rise in water demand for agriculture, industry, domestic, and environmental needs requires sagacious use of this limited resource. Since agriculture (mainly irrigation) is the major user of water, improving agricultural water management is essential. Efficient agricultural water management requires reliable estimation of crop water requirement (evapotranspiration). Evapotranspiration (ET) i...

Introduction Dust storms as one of the environmental hazards of the arid regions of the globe, including the southern, southwestern, eastern and central parts of Iran, has caused many environmental problems that confirm the need for studying and crisis managing its in scientific and executive congresses. Therefore, the present study attempts to evaluate the effects of climate elements on tempe...

Journal: :پژوهش آب در کشاورزی 0

determination of crops water requirement in different environmental conditions is essential for preparation of precise and suitable irrigation scheduling. the effect of soil compaction and texture on crop coefficient and evapotranspiration of maize was investigated in this study, which was conducted as a factorial experiment with a completely randomized design in a research farm in jey and qaha...

2004
Raj Vir Singh

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...

Journal: :International Journal of Environment, Agriculture and Biotechnology 2017

Journal: :Remote Sensing 2013
Xiaomei Jin Renhong Guo Wei Xia

Evapotranspiration is a major loss flux of the water balance in arid and semi-arid areas. The estimation of actual evapotranspiration has significance for hydrological and environmental purposes. The Surface Energy Balance System (SEBS) algorithm was applied to estimate actual evapotranspiration in the Qaidam Basin and its eight hydrological sub-regions, Northwest China. There were 3,036 cloud-...

2002
Vivek K. Arora

Available energy (often expressed in terms of potential evaporation) and precipitation largely determine annual evapotranspiration and runoff rates in a region. The ratio of annual potential evaporation to precipitation, referred to as the aridity index by Budyko, has been shown to describe the evaporation ratio (the ratio of annual evapotranspiration to precipitation) of catchments from a rang...

2004
Raul Rivas Vicente Caselles

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:

2010
CRISTINA SERBAN ALINA BARBULESCU

Estimating evapotranspiration is essential for understanding the water cycle of natural systems and for the management of the water resources in landscape systems. This paper presents a procedure to calculate the evapotranspiration using the remote sensing data and Grid Computing. Evapotranspiration was retrieved during satellite overpass and integrated for 24 hours on pixel-by-pixel base for d...

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