paid water use, the consolidated, mutually beneficial distribution of profits from
irrigation is based on the economic assessment of options based on the criterion of
additional net profit from irrigation, which is calculated by the formula:
(
)(
)
(
)
.
,
,
,
2
1
кр
U
U
U
Y
W
f
C
C
Y
W
U
f
C
C
W
U
F
−
+
−
−
+
+
−
=
, (1)
where F(
,
,W
U
) - additional net profit from irrigation, uan/ha; С - selling price,
uan/cent; С
1
, С
2
- prime cost, respectively, for irrigation and on the rich (without the
cost of water supply), uan/p; Y
п
- corresponding planned harvests, c/ha;
+
+
+
W
f
W
U
f
,
- functions of reducing yields per unit in case of non-irrigation and
rainfalls, in units of unit; U,U
кр
- the value of current and critical (limit) irrigation
norms, m
3
/ha;
- precipitation in a given year, m
3
/ha; W - the value of biologically
optimal irrigation norms, m
3
/ha;
- tariff for 1 m
3
of water, uan/m
3
.
Thus, the additional net income from irrigation depends on the specific conditions
of the year (
,
W
) and the choice of the actual irrigation rates (
U
). Taking into account
the above, based on the simulation model, one can construct a stochastic game matrix
with the nature of type (2) for the criterion of additional net profit:
U
1
… U
m
(
)
(
)
)
,
,
(
...
)
,
,
(
...
...
...
)
,
,
(
...
)
,
(
,
...
,
)
,
,
(
1
1
1
1
1
1
1
1
N
N
m
N
N
m
N
N
j
j
k
W
U
F
W
U
F
W
U
F
,ξ
W
U
F
W
W
W
U
F
=
(2)
For the conditions of the forecast year based on simulation model it is proposed
to calculate the functions of additional net profit from irrigation of the corresponding
crops. The graphical method makes it possible to determine the optimal values of
irrigation norms that correspond to the maximum value of the additional net profit from
irrigation (Fig. 2). The analysis of the criterion of additional net profit from the size of
the irrigation rate shows that biologically optimal irrigation is economically
advantageous at low water tariffs; when increasing the water tariff, the optimal
irrigation rate decreases, that is, the optimal water-saving irrigation regimes become.
The basic task of planning irrigation regimes based on a two-layer model is to
calculate and predict the dynamics of soil moisture in the calculated (or active layer of
soil, where the bulk of the root system is concentrated). For these purposes, one of the
most widely used and tested in practice water-balance model for the deficit of moisture
storage is used:
D
k
=D
n
+(А∙К∙Е – Р) – m, (3)
where D
k
, D
n
- the final and initial deficit of the calculation period, mm; Е - total
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