The graph shows the actual humidity values calculated for the OGH according to
the measured tensiometers of suction pressure [9]. The figure of the line reflects the
calculated and actual distribution of volumetric humidity with depth for a certain fixed
time (day).
The average relative error (predicted and actual values) is calculated by the
formula:
()
()
()
()
(
)
1
1
,,
N
j
t
j
t
j
j
М
f
e
N
=
=
(6)
Figure 8. Schedule of relative error (predicted and actual values) from time,%:
1-7 – relative error values for each experiment,%; 0 – mathematical expectation
(predicted and actual values),%
From rice 8 it is evident that the deviation of the predicted and actual values for
seven calculations for 15 days does not exceed 5%, which completely satisfies the
requirements for the accuracy of calculations for irrigation [10]. But with the increase
in the forecast days (more than 15), the deviation of predicted and actual values
increases significantly. This confirms the possibility and feasibility of using a multi-
layered model of moisture transfer for the calculation and operational planning of
irrigation.
CONCLUSION
The article presents a theoretical generalization and a new approach to the
development of scientific methods for optimization of the norms of paid water use for
irrigation of main agricultural crops on the basis of economically efficient and
environmentally sound technologies.
1. The method of system evaluation and optimization of the criterion of additional
net profit from irrigation, determination of optimal irrigation norms and choice of
irrigation regime during the years of different water supply at different rates of
irrigation water is proposed and substantiated.
Rel
at
iv
e
erro
r,
%
Days
1
2
3
4
5
6
7
0
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