Assessment of evapotranspiration estimation models for use in semi-arid environments

Dehghanisanij, Hossein; Yamamoto, T.; Rasiah, V.

doi:10.1016/s0378-3774(03)00200-2

Cited by 123 publications

(51 citation statements)

References 6 publications

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“…α is empirically derived and assumes the ratio of PET to equilibrium PET (no advection) is constant. The Priestley-Taylor model is therefore driven primarily by net radiation (R N ) and tends to perform best in humid areas and worse in arid areas, due in part to the equilibrium assumption (DehghaniSanij et al, 2004). The PT-JPL model retains the original α (1.26) and uses six parameters to modify PET for both humid and arid areas.…”

Section: The Pt-jpl Model For Evapotranspirationmentioning

confidence: 99%

Improving operational land surface model canopy evapotranspiration in Africa using a direct remote sensing approach

Marshall

Funk

et al. 2013

Hydrol. Earth Syst. Sci.

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Abstract. Climate change is expected to have the greatest impact on the world's economically poor. In the Sahel, a climatically sensitive region where rain-fed agriculture is the primary livelihood, expected decreases in water supply will increase food insecurity. Studies on climate change and the intensification of the water cycle in sub-Saharan Africa are few. This is due in part to poor calibration of modeled evapotranspiration (ET), a key input in continental-scale hydrologic models. In this study, a remote sensing model of transpiration (the primary component of ET), driven by a time series of vegetation indices, was used to substitute transpiration from the Global Land Data Assimilation System realization of the National Centers for Environmental Prediction, Oregon State University, Air Force, and Hydrology Research Laboratory at National Weather Service Land Surface Model (GNOAH) to improve total ET model estimates for monitoring purposes in sub-Saharan Africa. The performance of the hybrid model was compared against GNOAH ET and the remote sensing method using eight eddy flux towers representing major biomes of sub-Saharan Africa. The greatest improvements in model performance were at humid sites with dense vegetation, while performance at semi-arid sites was poor, but better than the models before hybridization. The reduction in errors using the hybrid model can be attributed to the integration of a simple canopy scheme that depends primarily on low bias surface climate reanalysis data and is driven primarily by a time series of vegetation indices.

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Section: The Pt-jpl Model For Evapotranspirationmentioning

confidence: 99%

Improving operational land surface model canopy evapotranspiration in Africa using a direct remote sensing approach

Marshall

Funk

et al. 2013

Hydrol. Earth Syst. Sci.

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“…Irrigation water amount (I) in all experiments was based on different fractions of the crop water requirement (ET c ), including over-and deficit irrigation. The crop water requirement (ET c ) was estimated based on the Penman-Monteith model (Allen et al, 1998), which is a model recommended for these regions by Dehghanisanij et al (2004). Soil water balance methods were used to monitor soil water content during the growing season by gravimetric measurements of soil moisture.…”

Section: Database and Experimental Site Descriptionmentioning

confidence: 99%

Assessment of wheat and maize water productivities and production function for cropping system decisions in arid and semiarid regions

Dehghanisanij

Nakhjavani

Tahiri

et al. 2008

Irrigation and Drainage

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The great challenge of the agricultural sector in countries located in arid and semiarid regions faced with severe water scarcity is to produce more food from less water. This may be achieved by increasing the crop water productivity (WP). Based on experiments conducted in different regions of Iran, it was found that the range of wheat WP was greater than that reported earlier by the FAO. The maize WP was high in the northwestern regions of Iran and less in the southwest. The wide ranges of WP (0.5-1.8 kg m À3 for wheat and 0.3-2.3 kg m À3 for maize) indicate tremendous opportunities for increasing agricultural production with less water. The variability of crop WP can be ascribed to climate, cropping calendar, soil characteristics, and irrigation water management. Wheat and maize WP of 1.5 and 1.7 kg m À3 were recommended as an optimum level to be considered in the cropping system of potential regions. Irrigation water applied for an optimum level of wheat and maize WP was about 2650 and 5900 m 3 ha À1 , respectively. The maximum wheat WP occurred under deficit irrigation, while for maize it was measured under full irrigation. Regions with higher annual rainfall and high silt content in soil were more productive under deficit irrigation management. Copyright # 2008 John Wiley & Sons, Ltd.key words: crop water productivity; crop water production function; wheat; maize; deficit irrigation

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“…This model has been validated in relation to the data measured by lysimeters under various climatic conditions. For this reason, it has been considered the best method to estimate ETo and is widely used as a standard for comparison with other empirical methods (Allen et al 2005, 1998, ASCE-EWRI 2005, Berti et al 2014, Djaman et al 2015, Dehghani Sanij et al 2004, Ghamarnia et al 2015, Itenfisu et al 2003, Jain et al 2008, Lima et al 2013, Pandey et al 2014, Pereira et al 2015, Tabari et al 2013, Widmoser 2009, Mohan and Arumugam 1996. Empirical or deterministic models with a physical basis, with or without random or probabilistic components, are used to calculate ETo (Soares et al 2003, Borges andMendiondo 2007).…”

Section: Introductionmentioning

confidence: 99%

Three decades of reference evapotranspiration estimates for a tropical watershed in the eastern Amazon

Júnior

Souza

Tavares

et al. 2017

An. Acad. Bras. Ciênc.

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This study estimated the reference evapotranspiration rate (ETo) for the Itacaiúnas River Watershed (IRW), Eastern Amazonia, and measured the accuracy of eight empirical equations: Penman-Monteith (PM), Priestley-Taylor (PT), Hargreaves and Samani (HS), Camargo (CAM), Thornthwaite (TH), Hamon (HM), Kharrufa (KF) and Turc (TC) using monthly data from 1980 to 2013. In addition, it verifies the regional applicability to the IRW using a for the Marabá-PA station. The methods TC and PM (FAO56) presented the best results, which demonstrate that radiation and higher temperatures are the dominant drivers in the Evapotranspiration process, while relative humidity and wind speed have a much smaller impact. The temporal and spatial variability of ETo for IRW show has strong seasonality, increasing during the dry season and decreasing during the rainy season. The statistical analyses at 1% level of significance, indicates that there is no correlation of the residuals between the dry and rainy seasons, and test of the physical parameters such as mean temperature, solar radiation and relative air humidity explains the variations of ETo.

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Assessment of evapotranspiration estimation models for use in semi-arid environments

Cited by 123 publications

References 6 publications

Improving operational land surface model canopy evapotranspiration in Africa using a direct remote sensing approach

Improving operational land surface model canopy evapotranspiration in Africa using a direct remote sensing approach

Assessment of wheat and maize water productivities and production function for cropping system decisions in arid and semiarid regions

Three decades of reference evapotranspiration estimates for a tropical watershed in the eastern Amazon

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