Teste de modelos para estimativa de balanço de radiação em diferentes escalas para a região de Jaboticabal, SP

摘要: The net radiation (Rn) in agroecosystems is the amount of energy that available environment to heating processes living organisms, air and soil; perspiration animals plants; photosynthesis water evaporation. Rn defines type climate weather conditions prevailing a region affecting availability thermal water, fundamental understanding genotype-environment, which ultimately determine productivity agricultural system. usually used models studies. sustainability economic viability zootechnical activity dependent on positive interaction between animal environment. Environmental factors such as shading, exchanges sensible heat (conduction, convection skin) latent losses (evaporation transpiration), conditioned by Rn, must be managed provide best results. present study was conducted develop test for accurate precise balance scales daily, monthly seasonal ten-day Jaboticabal - SP, due importance estimates activities. We daily meteorological data from station located Jaboticabal, SP (coordinates: 21 ° 14'05 "South, 48 17'09" West, 615m altitude) at Universidade Estadual Paulista "Julio Mesquita Filho" FCAV/UNESP situation default grass "Bahiagrass" during period 20/08/2005 20/01/2012. were maximum temperature (Tmax), minimum (Tmin) mean (TMED); relative humidity (URMax), (URMin) average (URMed) precipitation (mm), velocity (m/s), Qo, solar (MJ m-2), sunshine (hour) meter m²), soil two depths (Tsoil2CM, Tsoil5CM) class A pan evaporation (TCA) (mm). measures taken radiometer reference other models. tested those reported NORMAN et al. 1995 PRIESTLEY TAYLOR, 1972. developed regressions with MAPE (Mean Absolute Percentage Error), R² (Accuracy) RMSEs (root error quadratic systematic) different time scales. mechanistic models, PRIESTLEY-TAYLOR NORMAN, had low accuracy all analyzes; equal 498.12%. This high amplitude estimated regarding observed, making values (accuracy) low. equation data, called = f (all), most cases showed result. However, purpose practical use not indicated because his job will need lot information collection difficult. standard methodology estimating recommended FAO, however, this method presents some difficulties measured required sensor (balance-radiometer) often has its value. Thus, using Qg an indicator ends up getting compromised handling. By equations Q0 independent variable suitable. Seeking greater practicality without losing precision, utilization. (Q0, n) work having precision convenience use.