The Experts below are selected from a list of 1938 Experts worldwide ranked by ideXlab platform
Parajka Juraj - One of the best experts on this subject based on the ideXlab platform.
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Level A Pan Europe Solar Index for estimation of Potential evaporation January
2018Co-Authors: Parajka JurajAbstract:Solar Index for estimation of Potential evaporation January. Solar Index (SI) maps are input needed for spatial estimation of potential evaporation by using modified Blaney Criddle method (Schrödter 1985, Parajka et al., 2003). SI maps are available for each month. Spatial resolution: 1km2. Solar Index maps (SI_xxx) for estimation of potential evaporation by using modified Blaney Criddle method. Maps are available for each month (xxx). Format ArcGIS ASCII grid. Maps are estimated from GTOPO30 DEM. Coordinates: geographical. SI index is estimated in GIS GRASS (r.sun module)
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Level A Pan Europe Solar Index for estimation of Potential evaporation May
2018Co-Authors: Parajka JurajAbstract:Solar Index for estimation of Potential evaporation May. Solar Index (SI) maps are input needed for spatial estimation of potential evaporation by using modified Blaney Criddle method (Schrödter 1985, Parajka et al., 2003). SI maps are available for each month. SI maps are available for each month. Spatial resolution: 1km2. Solar Index maps (SI_xxx) for estimation of potential evaporation by using modified Blaney Criddle method. Maps are available for each month (xxx). Format ArcGIS ASCII grid. Maps are estimated from GTOPO30 DEM. Coordinates: geographical. SI index is estimated in GIS GRASS (r.sun module)
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Level A Pan Europe Solar Index for estimation of Potential evaporation September
2018Co-Authors: Parajka JurajAbstract:Solar Index for estimation of Potential evaporation September. Solar Index (SI) maps are input needed for spatial estimation of potential evaporation by using modified Blaney Criddle method (Schrödter 1985, Parajka et al., 2003). SI maps are available for each month. SI maps are available for each month. Spatial resolution: 1km2. Solar Index maps (SI_xxx) for estimation of potential evaporation by using modified Blaney Criddle method. Maps are available for each month (xxx). Format ArcGIS ASCII grid. Maps are estimated from GTOPO30 DEM. Coordinates: geographical. SI index is estimated in GIS GRASS (r.sun module)
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Level A Pan Europe Solar Index for estimation of Potential evaporation March
2018Co-Authors: Parajka JurajAbstract:Solar Index for estimation of Potential evaporation March. Solar Index (SI) maps are input needed for spatial estimation of potential evaporation by using modified Blaney Criddle method (Schrödter 1985, Parajka et al., 2003). SI maps are available for each month. SI maps are available for each month. Spatial resolution: 1km2. Solar Index maps (SI_xxx) for estimation of potential evaporation by using modified Blaney Criddle method. Maps are available for each month (xxx). Format ArcGIS ASCII grid. Maps are estimated from GTOPO30 DEM. Coordinates: geographical. SI index is estimated in GIS GRASS (r.sun module
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Level A Pan Europe Solar Index for estimation of Potential evaporation November
2018Co-Authors: Parajka JurajAbstract:Solar Index for estimation of Potential evaporation November. Solar Index (SI) maps are input needed for spatial estimation of potential evaporation by using modified Blaney Criddle method (Schrödter 1985, Parajka et al., 2003). SI maps are available for each month. SI maps are available for each month. Spatial resolution: 1km2. Solar Index maps (SI_xxx) for estimation of potential evaporation by using modified Blaney Criddle method. Maps are available for each month (xxx). Format ArcGIS ASCII grid. Maps are estimated from GTOPO30 DEM. Coordinates: geographical. SI index is estimated in GIS GRASS (r.sun module)
V. P. Singh - One of the best experts on this subject based on the ideXlab platform.
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Cross Comparison of Empirical Equations for Calculating Potential Evapotranspiration with Data from Switzerland
Water Resources Management, 2002Co-Authors: V. P. SinghAbstract:Earlier studies (Singh and Xu, 1997; Xu and Singh, 2000, 2001) have evaluated and compared various popular empirical evapotranspiration equations that belonged to three categories:(1) mass-transfer based methods, (2) radiation based methods, and(3) temperature-based methods; and the best and worst equations of each category were determined for the study regions. In this study a cross comparison of the best or representative equation forms selected from each category was made. Five representativeempirical potential evapotranspiration equations selected from the three categories, namely: Hargreaves and Blaney-Criddle (temperature-based), Makkink and Priestley-Taylor (radiation-based) and Rohwer (mass-transfer-based) were evaluatedand compared with the Penman-Monteith equation using daily meteorological data from the Changins station in Switzerland.The calculations of the Penman-Monteith equation followed theprocedure recommended by FAO (Allen et al ., 1998). Thecomparison was first made using the original constant valuesinvolved in each empirical equation and then made using therecalibrated constant values. The study showed that: (1) theoriginal constant values involved in each empirical equationworked quite well for the study region, except that the valueof α = 1.26 in Priestley-Taylor was found to be too high and therecalibration gave a value of α = 0.90 for the region.(2) Improvement was achieved for the Blaney-Criddle method by addinga transition period in determining the parameter k . (3) The differences of performance between the best equation forms selected from each category are smaller than the differences between different equations within each category as reportedin earlier studies (Xu and Singh, 2000, 2001). Further examinationof the performance resulted in the following rank of accuracy ascompared with the Penman-Monteith estimates: Priestley-Taylor andMakkink (Radiation-based), Hargreaves and Blaney-Criddle (temperature-based) and Rohwer (Mass-transfer).
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cross comparison of empirical equations for calculating potential evapotranspiration with data from switzerland
Water Resources Management, 2002Co-Authors: Chongyu Xu, V. P. SinghAbstract:Earlier studies (Singh and Xu, 1997; Xu and Singh, 2000, 2001) have evaluated and compared various popular empirical evapotranspiration equations that belonged to three categories:(1) mass-transfer based methods, (2) radiation based methods, and(3) temperature-based methods; and the best and worst equations of each category were determined for the study regions. In this study a cross comparison of the best or representative equation forms selected from each category was made. Five representativeempirical potential evapotranspiration equations selected from the three categories, namely: Hargreaves and Blaney-Criddle (temperature-based), Makkink and Priestley-Taylor (radiation-based) and Rohwer (mass-transfer-based) were evaluatedand compared with the Penman-Monteith equation using daily meteorological data from the Changins station in Switzerland.The calculations of the Penman-Monteith equation followed theprocedure recommended by FAO (Allen et al., 1998). Thecomparison was first made using the original constant valuesinvolved in each empirical equation and then made using therecalibrated constant values. The study showed that: (1) theoriginal constant values involved in each empirical equationworked quite well for the study region, except that the valueof α=1.26 in Priestley-Taylor was found to be too high and therecalibration gave a value of α=0.90 for the region.(2) Improvement was achieved for the Blaney-Criddle method by addinga transition period in determining the parameter k. (3) The differences of performance between the best equation forms selected from each category are smaller than the differences between different equations within each category as reportedin earlier studies (Xu and Singh, 2000, 2001). Further examinationof the performance resulted in the following rank of accuracy ascompared with the Penman-Monteith estimates: Priestley-Taylor andMakkink (Radiation-based), Hargreaves and Blaney-Criddle (temperature-based) and Rohwer (Mass-transfer). Copyright Kluwer Academic Publishers 2002
F I Idike - One of the best experts on this subject based on the ideXlab platform.
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Blaney morin nigeria bmn evapotranspiration model a technical note
Nigerian Journal of Technology, 2005Co-Authors: F I IdikeAbstract:Duru [1] presented a modified form of the Blaney-Morin potential evapotranspiration equation christened Blaney-Morin- Nigeria (BMN) Evapotranspiration (ET) model for use in Nigeria. In this work, Duru recognize the very wide variability of relative humidity in Nigeria and consequently the very important role this parameter is bound to play in the evapotranspiration process in this geographical region (Nigeria). Thus he (Duru) correctly surmised that any Et model that would reasonably estimate Potential evapotranspiration (PET) in Nigeria must involve humidity term as a crucial parameter.
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evaluation analysis and modification of the Blaney morin nigeria bmn evapotranspiration model
Nigerian Journal of Technology, 2002Co-Authors: F I Idike, C E AnekweAbstract:The analytical approach of the Blaney-Morin-Nigeria (BMN) evapotranspiration model was applied to data sets obtained from seventeen locations in Nigeria and the values of the constants m and H in the BMN model, Equation 1 were not as consistently comparable as expected. Thereupon, the Standard Difference (SDF) method was applied to each of the seventeen locations (designated as model ETPP4), to each of the five regions formed by pooling data from meteorologically similar locations (ETPP3) and to the pooled data from all locations (ETPP1). The values of m and H thus obtained were consistently comparable and within the range considered acceptable for the country. While the models predict potential evapotranspiration (PET) more accurately than the Penman equation under the Nigerian conditions, their performances are similar to that of the BMN model. However, ETPP4 and ETPP3, produce better prediction in their corresponding locations and regions while ETPPI predicts PET slightly better than the 3MN model at those locations where the BMN model was not originally evaluated. Consequently, the SDF method is recommended as a procedural modification of the development of the BMN model and the most general form of the models, ETPPI (m = .29, H = 508) is recommended as a refinement of the BMN model.
Cristobal Reyeshernandez - One of the best experts on this subject based on the ideXlab platform.
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shelf slope exchanges and particle dispersion in blanes submarine canyon nw mediterranean sea a numerical study
Continental Shelf Research, 2015Co-Authors: Miguel Angel Ahumadasempoal, Maria Del Mar Flexas, Raffaele Bernardello, Nixon Bahamon, Antonio Cruzado, Cristobal ReyeshernandezAbstract:Abstract A climatological simulation performed with a fine-resolution (∼1.2 km) 3D circulation model nested in one-way to a coarse-resolution (∼4 km) 3D regional model is used to examine the cross-shelf break water exchange in the Blanes submarine canyon (∼41°00′–41°46′N; ∼02°24′–03°24′E). A Lagrangian particle-tracking model coupled to the fine-resolution 3D circulation model is used to investigate the role of the incident regional flow (i.e. the Northern Current, NC) and its seasonal variability on the dispersion and residence time of passive particles inside Blanes Canyon. The NC flows southwestward, along the slope, with the coastline to the right. Water is advected offshore/onshore at the upstream/downstream canyon walls, with a net water transport toward the slope (i.e. offshore). The amount of water moved across the shelf break of the upstream wall is approximately three times larger than the amount moved across the shelf break of the downstream wall. This preferential zone for cross-shelf break water exchange is explained by the asymmetric geometry of the canyon and the orientation of the incident current with respect to the canyon bathymetry. Passive particles released upstream Blanes Canyon between the mid-shelf and the upper-slope drift within the NC and accumulate over the shelf edge of the canyon. About half of the particles released at depths above the shelf break move towards shallower areas inside the canyon. In contrast, about two-thirds of particles released below the shelf break move to deeper areas. Particle dispersion is higher under weakly (e.g. winter) than strongly (e.g. summer) stratified conditions. The residence time of passive particles inside the canyon (∼4–6 days) is double than the residence time downstream of the canyon, indicating that the canyon acts as an efficient retention zone for passive particles.
Slavisa Trajkovic - One of the best experts on this subject based on the ideXlab platform.
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Comparative analysis of 31 reference evapotranspiration methods under humid conditions
Irrigation Science, 2013Co-Authors: Hossein Tabari, Mark E. Grismer, Slavisa TrajkovicAbstract:Evaluation of simple reference evapotranspiration (ET_o) methods has received considerable attention in developing countries where the weather data needed to estimate ET_o by the Penman–Monteith FAO 56 (PMF-56) model are often incomplete and/or not available. In this study, eight pan evaporation-based, seven temperature-based, four radiation-based and ten mass transfer-based methods were evaluated against the PMF-56 model in the humid climate of Iran, and the best and worst methods were selected from each group. In addition, two radiation-based methods for estimating ET_o were derived using air temperature and solar radiation data based on the PMF-56 model as a reference. Among pan evaporation-based and temperature-based methods, the Snyder and Blaney–Criddle methods yielded the best ET_o estimates. The ET_o values obtained from the radiation-based equations developed here were better than those estimated by existing radiation-based methods. The Romanenko equation was the best model in estimating ET_o among the mass transfer-based methods. Cross-comparison of the 31 tested methods showed that the five best methods as compared with the PMF-56 model were: the two radiation-based equations developed here, the temperature-based Blaney–Criddle and Hargreves-M4 equations and the Snyder pan evaporation-based equation.
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estimation of fao Blaney criddle b factor by rbf network
Journal of Irrigation and Drainage Engineering-asce, 2000Co-Authors: Slavisa Trajkovic, Miomir S Stankovic, Branimir TodorovicAbstract:This technical note presents the application of a Radial Basis Function (RBF) network to estimate the FAO Blaney-Criddle b factor. Tabular b values are given in the United Nations Food and Agriculture Organization Irrigation and Drainage Paper Number 24. The b values obtained by the RBF network are compared to the appropriate b values produced using regression equations. The RBF network predicted b values better than the regression equations. An example is given to illustrate the simplicity and accuracy of the RBF network for b factor estimation.