poster - International Conference of Agricultural Engineering

accumulated ETo (mm dia -1 )
5
TABELA 4: Regressions between the daily values of radiation balance in the surfaces
studied and radiation balance on horizontal surface (fall-winter).
Regression
y = a x + b
Linear coefficient (b) Angular Coefficient
(a)
Correlation
Coefficient (R 2 )
Q * 10N = a Q * H + b 1.9166 (*) 0.9807 0.9599
Q * 20N = a Q * H + b 3.4966 (*) 0.9299 0.8863
Q * 10E = a Q * H + b 0.6142 (*) 1.0225 0.9915
Q * 20E= a Q * H + b 0.7197 (*) 1.0136 0.9364
y = a x
Q * 10S = a Q * H 0.9897 0.9909
Q * 20S = a Q * H 0.8715 0.9624
Q * 10W = a Q * H 1.0463 0.9914
Q * 20W = a Q * H 0.9751 0.9623
Figures 1 and 2 show the estimation of reference evapotranspiration (ETo) accumulated in
(mm d -1 ), in the surfaces studied, in the spring-summer and autumn-winter period,
respectively. Note that the accumulated ETo on surfaces in the spring-summer periods were
758.6, 781.3, 757.2, 782.9, 741.8, 774.5, 769.6, 760.4 and 752.5 mm, to H, 10N, 10S, 20N,
20S, 10E, 10W, 20E and 20W, respectively. In the fall-winter period the accumulated Eto
were 561.9, 643.8, 557.3, 695.8, 504.5, 601.0, 582.6, 602.0 and 550.8 to H, 10N, 10S, 20N,
20S, 10E, 10W, 20E and 20W and 20W, respectively. The results obtained show the
importance of such studies, which allow the correction of the Penman-Monteith for surfaces
with different expositions and slopes.
900
800
700
600
500
400
300
200
100
0
H
spring-summer
10N 10S 20N 20S 10E 10W 20E 20W
FIGURA 1: Accumulated ETo on surfaces during spring-summer (2011-2012).