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Establishment of additional norms for irrigation
water
Z Mirkhasilova
1
*
, M Yakubov
2
, L Irmukhamedova
1
, N Rakhimov
2
, N Norkuzieva
1
1
“Tashkent Institute of Irrigation and Agricultural Mechanization Engineers” National Research
University, Kary Niyoziy str., 39, 100000, Tashkent, Uzbekistan
2
Scientific research institute of irrigation and water problems, 100187, h. 11, Karasu-4, Tashkent,
Uzbekistan
Abstract. Due to the scarcity of water resources, there is a need for an
additional source of irrigation. Drainage waters can serve as such sources.
To use these waters, it is necessary to develop a number of measures. The
aim of the study is to reduce the negative consequences by increasing the
norms of preventive irrigation. It is vital to fulfilling the tasks set:
calculation of additional water supply rates and irrigation regime when
designing the use of drainage water for irrigation. As a result of field
studies and according to the methodology of classifications developed by
the Central Asian Research Institute of Irrigation (SANIIRI) analysis of the
suitability for irrigation of pumped water from vertical drainage wells in
the areas of the Fergana region. Studies conducted by scientists in Central
Asia have shown that one of the methods to prevent soil salinization in the
intra-contour use of collector-drainage water is the requirements with the
following conditions: the ratio of total water supply to total evaporation
and the ratio of drainage flow to the water supply. Taking into account the
established coefficient, the irrigation rate must be increased depending on
the mineralization of water and the mechanical composition of the soil.
1 Introduction
When using drainage water for the irrigation of agricultural crops, it is necessary to develop
measures to reduce the negative consequences by increasing the norms of preventive
irrigation. It should be noted that at present there is no single methodology for calculating
additional water supply rates and irrigation regimes when designing the use of drainage
water. In contrast, for calculating the irrigation regime and irrigation norms when using
(fresh) water, a number of methods are known, such as empirical, water-balance, heat-
balance, and others, based on taking into account bioclimatic indicators, as well as methods
where evaporation (water consumption) is determined experimentally way.
The aim of the study is to reduce the negative consequences by increasing the norms of
preventive irrigation. The objectives of the study include the calculation of additional water
supply rates and irrigation regimes when designing the use of drainage water for irrigation.
The object of the study is the drainage waters of the Fergana region.
* Corresponding author: mzulfiya.k@mail.ru
© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons
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2 Materials and methods
Research materials include data from field studies, meteorological observation stations, and
others. The article uses methods for calculating the water-salt balance, the weight method
for measuring soil moisture, computer programming, and other methods.
3. Results
When designing the irrigation regime with fresh water in the conditions of Central Asia, the
recommendations of the Institute "Sredagiprovodkhlopok" are widely used. For irrigation
with high mineralization waters in order to exclude soil salinization, and reduce the fertility
and productivity of agricultural land, it is necessary to provide additional water rates, best
of all in the autumn-winter period. They can also be called the washout coefficient [1, 2].
Flushing coefficients can be of two ways:
- based on the generalization of full-scale experiments on the use of collector-drainage
waters;
- based on various calculation methods, based on solving the equations of water-salt
balances or systems of nonlinear partial differential equations [3].
Table 1. Volume and quality of pumped water in the Ferghana region for 2020.
District name
Number
of wells,
pieces.
Volume of
pumped
water,
million m3
Mineralization of
pumped water, g/l
Suitability for
irrigation
dense
residue Chlorine
Altyaryk 146 40.6 1.92 0.11 satisfactory
Akhunbabaevsk
y 52 7.3 1.23 0.08 satisfactory
Baghdad 124 52.5 1.72 0.16 satisfactory
Besharik 109 7.6 1.73 0.14 satisfactory
Dangara 72 7.1 1.89 0.15 satisfactory
Kuva 232 89.2 1.97 0.16 satisfactory
Rishtan 146 70.6 2.2 0.13 satisfactory
Tashlak 114 34.9 1.38 0.08 satisfactory
Uzbekistan 112 20.9 2.09 0.13 satisfactory
Uchkuprik 42 6.3 2.17 0.15 satisfactory
Furkat 56 1.4 1.7 0.15 satisfactory
Yazyavan 10 0.6 1.49 0.06 satisfactory
Kuvasay 26 11.6 1 0.05 good
Total for
Fergana region 1264 361 1.48 0.06 satisfactory
Numerous studies that have been conducted in Central Asia have shown that one of the
methods to prevent soil salinization during the in-contour use of collector-drainage water is
the requirements with the following conditions:
- ratio of total water supply to total evaporation:
∑()
>(1.2 − 1.1)
(1)
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- ratio of drainage flow to water supply:
∑ ( + ) ≥ 0.3 − 0.4
(2)
where Km – coefficient, degree of mineralization of water (according to Km can be taken
within 1.2-1.4). [5]
For predictive calculations, the established patterns of actual reclamation regimes were
calculated during long-term field studies of soil reclamation processes and elements of the
water-salt balance.
To establish the leaching regime of soils according to the above method, the conditions
of the association of water users for the operational period in the annual and long-term
context were used. The above equations were taken as a basis based on many years of
research in the Fergana region. For the implementation of predictive indicators of the
ameliorative state of irrigated lands during long-term use for irrigation of mineralized
waters and flushing. The irrigation regime was as follows: pre-irrigation humidity during
the growing season was 70% of the field moisture capacity, and after irrigation 100%.
Mineralization of irrigation and washing water was taken according to field studies of 1.5-
2.5 g/l. The water-salt balance during the growing season is positive, and the total annual is
negative, which means a flush irrigation regime is created. The calculations were performed
according to the method developed at SANIIRI [15]. In predictive calculations for large
irrigated areas, with different types of drainage, it is effective to use the balance method [6].
The calculation of the balance must be carried out in the context of the month since the data
of the operational services are used as the initial ones. They are established on the basis of
average monthly values with the elements included for them. Predicted groundwater depths
are calculated using the general balance equations according to S.F. Averyanov [15]:
=
н
−
=
=
+
/
+
+
+
/
+ −
− С − О ± Р −
−
(3)
where ΔW is total changes in the stock of moisture in the territory of the balance contour;
Fmk is the filtration from the main channel; Vv/d is the water supply by groundwater from
vertical drainage wells; ETm is the evapotranspiration of the irrigated area; C is the
discharge from irrigation fields; Dg is wedging out of groundwater into horizontal drainage;
Dw is the volume of pumped water; Fmk, Fmg, and Fm/x are filtration losses. Moisture
reserves in the balance layer can be calculated by using the formula obtained using the
empirical dependence:
= 4.5 − ℎ√10000 [
/
]
(4)
where n is porosity; h is the depth of groundwater; A is a parameter characterizing the
permeability of the soil (for homogeneous loamy soils A = 0.11 m2, for heavy soils it is
0.12 m2; for layered ones, it is 0.15 m2).
Groundwater balance:
= ℎ0 ∗ 104 = + + / ± + − О ± − –
(5)
Water and salt balance of the aeration zone:
∆
− ∆
=
+
+(1 − )
± + ± −
−
(6)
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−
=
+ (1 − )
−
±
(7)
Salt balance of the surface layer of groundwater:
−
=
±
−
±
±
(8)
where Fvx - seepage losses from on-farm canals; Wak,Wan - moisture reserves in the
aeration zone at the beginning and end of the calculation period; Oc is the outflow of
groundwater from the calculated surface layer of groundwater to the underlying ones; Sak
and San are salt content in the aeration zone at the beginning and end of the calculation
period; Cg and Cq describe the salt content in the corresponding elements of water
balances; Sd and Sz are diffusion and sorption salt exchange, between the calculated and
neighbouring layers of groundwater.
= ℎ ∗ н ∗ ∗
∗ ∗ 100
(9)
where Sah is the salt content in the soils of the aeration zone, % of the weight of dry soil; R
is the volumetric mass of the soil zone of aeration, in t/m3 unit; ξ is the coefficient of
transition from water extracts to the initial estimated salt reserves, which is for chloride
soils 1.17 g/l, and for chloride-sulfate, it is 1.41 g/l. The removal of salts in the soils of the
aeration zone and seepage waters (+) is determined in our scheme according to the
formula [15]:
=
⌊1 −
(а
_)
⌋
(10)
where γ is the salt leaching constant, which is for chloride soils 1.5, and for chloride-
sulfate it is 4.25;
-fold rate of water exchange in the soils of the aeration zone
= /(ℎ
)
(11)
where ma is the active porosity. For the case of feeding the aeration zone with
groundwater:
= 10
µ
(12)
where µ
is the average mineralization of groundwater for the calculation period, g/l
(determined from the water-salt balances of the surface layer of groundwater). Under
conditions of close occurrence of groundwater, the role of Sq and Sf in their mineralization
is not great. In this case, the hydrochemical regime is formed mainly due to the
consumption of groundwater for evapotranspiration and infiltration from irrigated fields.
The salt content in the aeration zone at the end of the calculated time interval
=
а
± +
+ (1 − )
+
−
(13)
Due to the fact that in the intra-annual section, the mineralization and depth of
groundwater are subject to significant fluctuations, the calculated thickness of the surface
layer ℎ
is lower: with the rise and fall of the groundwater level, respectively
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= (
х
± )(1 −
( + ± ))
(14)
at х < | − |, = 0
Salt balance elements of the surface layer of groundwater are defined as follows:
= ℎ
100
(15)
=
(16)
= (
+Nα
) ± −
(17)
==
(18)
µ
=
(19)
where Se1AA is the salt content in soils of the calculated groundwater layer, (%) of the
weight of dry soil; θ is the fresh factor from the salt content in soils (%) to express the
mineralization of groundwater, in g/l unit [6]. R is the volumetric mass of the soil zone of
aeration, C is the discharge from irrigation fields, and µ is the average mineralization of
groundwater for the calculation period
The salt balance of the aeration zone of an irrigated field is calculated according to the
formulas and specific values for the "net" area. When determining the water-salt balances
of the root layer, the following assumptions were made: the root layer during the entire
growing season is assumed to be 0.8 m; change in moisture reserves in the root layer ΔWak
for monthly intervals; the salinity of the ascending groundwater flow feeding the root zone
is equal to the average mineralization of the aeration zone layer between the groundwater
level and the root zone; salts coming from groundwater into the aeration zone with an
upward current from their surface are completely deposited in the root zone. The estimated
irrigation norm net, established for a complex hectare according to fresh water was 5200
m3/ha. Taking into consideration the coefficient established above, the irrigation rate must
be increased depending on the mineralization of water and the mechanical composition of
the soil [10]. At the same time, the irrigation rate in the Fergana region will be from 5750
m3/ha to 6250 m3/ha for permeable soils per year with mineralization of 1.5-2.5 g/l. To
consider the efficiency of irrigation equipment equal to 0.70, the calculated irrigation norms
should be 8210-8925 m3/ha (gross). Additional norms of preventive irrigation are
recommended to be applied in the autumn-winter period. The results of calculations for
predicting the total water balance, water and salt balance of the aeration zone, the content of
easily soluble salts in the aeration zone and the root layer, as well as the salinity of
groundwater and the root layer according to the above method, are given in Table 2. The
presented data show that the calculated rates of additional irrigation (i.e., flushing regime
coefficients) are quite sufficient to ensure the required reclamation state of lands when
using pumped groundwater [7,8,12].
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Table 2. Total water balance of the field when using pumped water for different leaching
regime coefficients (Kpr).
Кpr
Income, m3/ha Receipt
amount
Receipt amount,
m3/ha
Amount of
expense
Balance
±∆Wот
Вb
r
А Fк P ЕТп Dr Сbr
Кpr
=
1.15
82
10 1680 810 2000 12700 6710 3110 620 10440 +2260
Кpr
=
1.25
89
25 1680 880 2000 13485 6710 3380 710 10800 +2685
Table 3. Salt balance of the aeration zone.
Elements At Mot = 1.5 g/l At Mot = 2.5 g/l
salt, t/ha salt, t/ha
SА 7.5 1.15
О
р
7.5 12.5
Coming: SNnov 2.18 2.67
S(1-α)Fк 0.61 1.1
Total 11.44 17.42
Consumption: S±q 14.85 18.13
Ssbr 1.06 1.78
Total 15.91 19,91
Difference -4.48 ∆= -2.49
Table 4. Forecast of the main indicators of the ameliorative state of irrigated lands when using
pumped water.
Period Indicators
Sa, %
,%
М
,g/l
кс
,
%
М
с
, g/l
Initial 0.350 0,289 5,000 0,275 3,920
Final 0,250 0,270 4,271 0,264 3,777
4 Discussion
The water balance of a territory is a quantitative expression of its water regime, which
determines the ratio of irretrievable water consumption and return water runoff. It is this
ratio in each specific area and at each level of water management construction that
determines the intensity of flow change in the process of its use. Researchers have
developed a methodology for assessing the conditions for the use of vertical drainage, on
the basis of which scientists found that on the territory of Uzbekistan on the total area in
need of drainage of 4.5 million hectares, the land the possible use of vertical drainage is
2.68 million hectares, including in the Fergana Valley, respectively, from 0.706 million
hectares to 0.53 million hectares [11]. Despite the large volumes of research work
performed, issues related to the use of drainage water need to be addressed. Their solution
is connected with conducting deep theoretical and long-term field studies on typical pilot
production sites [9,13].
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5 Conclusions
The results of chemical analyzes showed that the salinity of pumped water from the vertical
drainage wells varies from 1 (Kuvasoy town) to 1.99 g/l (Altyaryk district) in terms of solid
residue, and from 0.05 g/l to 0.17 g/l in terms of chlorine. The quality of these waters is
satisfactory and can be recommended for irrigation.
The results of calculations for predicting the overall water and salt balance of the
aeration zone, as well as the salinity of groundwater and the root layer, show that the
calculated rates of additional irrigation (i.e, flushing regime coefficients) are quite sufficient
to ensure the required reclamation state of the land when using pumped groundwater. The
established values of the flushing regime coefficient are generally close to the data of other
scientists, and their comparison showed that they differ by no more than 10-15%.
References
1. B. Matyakubov, G. Goziev, and U. Makhmudova, State of the inter-farm irrigation
canal: in the case of Khorezm province, Uzbekistan. Ural Environmental Science
Forum “Sustainable Development of Industrial Region” (UESF-2021) E3S Web of
Conferences 258, 03022 https://doi.org/10.1051/e3sconf/202125803022 (2021)
2. B. Matyakubov, D. Yulchiyev, I. Kodirov, and G. Axmedjanova, The role of the
irrigation network in the efficient use of water. CONMECHYDRO – 2021, E3S Web
of Conferences 264, 03018, https://doi.org/10.1051/e3sconf/202126403018 (2021)
3. B. Matyakubov, R. Koshekov, M. Avlakulov, and B. Shakirov, Improving water
resources management in the irrigated zone of the Aral Sea region.
CONMECHYDRO – 2021, E3S Web of Conferences 264, 03006,
https://doi.org/10.1051/e3sconf/202126403006 (2021)
4. Z. Mirkhasilova, L. Irmuhamedova, S. Kasymbetova, G. Akhmedjanova, and M.
Mirkhosilova, Rational use of collector-drainage water CONMECHYDRO – 2020 IOP
Conf. Ser.: Materials Science and Engineering, Volume 883, 012092 (2020)
5. Z. Mirkhasilova, M. Yakubov, and L. Irmukhomedova, Irrigated of the cultivated area
with groundwater from vertical drenage wells. CONMECHYDRO – 2021 E3S Web of
Conferences 264, 01015, https://doi.org/10.1051/e3sconf/202126401015 (2021)
6. I. Akhmedov, and Z. Mirkhasilova, Construction of vertical drainage wells using
corrosion resistant materials. CONMECHYDRO – 2021 E3S Web of Conferences 264
04016 https://doi.org/10.1051/e3sconf/202126404016 (2021)
7. N. Saidhujaeva, U. Nulloev, Z. Mirkhasilova, B. Mirnigmatov, and L. Irmukhamedova,
Production of Plant Product as a Process of Functioning Biotechnical System.
International Journal of Engineering and Advanced Technology ISSN: 2249-8958, 9
Issue-1, (2019)
8. Z.K. Mirkhasilova, Ways to improve the water availability of irrigated lands. European
Science Review No 7-8 ISSN 2310-5577, (2018)
9. Kh.M. Yakubova, L.Z. Sherfedinov, and J.K. Ishchanov, Problems of formation and
regulation of collector-drainage flow in the Aral Sea basin. Improving the efficiency of
common pool resources management in transition: keys study of irrigation water and
pasture InDeCA-6/2015 Tashkent, (2015)
10. S. Isayev, Sh. Mardiyev, and Z. Kadirov, Modeling the absorption of nutrients by the
roots of plants growing in a salted soil Journal of Critical Reviews ISSN- 2394-5125
Volume 7 Issue, (2020)
7
E3S Web of Conferences 386, 02002 (2023)
GISCA 2022 and GI 2022
https://doi.org/10.1051/e3sconf/202338602002
11. I. Urazbaev, S. Kasimbetova, G. Akhmedjanova, M. Pulatova, and S.H. Mardiev,
Fundamentals of Effective use of Water Resources of Irrigated Lands in South
Karakalpakstan. Annals of R.S.C.B ISSN:1583-6258 Vol. 25 Issue 3, (2021)
12. S. Kasimbetova, D. Ergashova, G. Akmedjanova, Sh. Mardiev, and A. Malikov,
Application of magnetized water on the washing of salted lands under the conditions of
the low village of the Amudarya River. Journal of Advanced Research in Dynamical
and Control Systems 12 (2 Special Issue), (2020)
13. M.A. Yakubov, R.K. Ikramov, T. Jalilova, and N.M. Karimova, On the question of the
methodology for predicting the mineralization of soil solution and groundwater in their
close occurrence on large irrigated tracts. Sat. scientific works of SANIIRI, (1980)
14. N.N. Khodjibaev, and L.Z. Sherfedinov, Issues of hydrogeological forecasting in arid
areas (Tashkent), (1982)
15. S.F. Averyanov, Fight against salinization of irrigated lands. (M.: Kolos), (1978)
8
E3S Web of Conferences 386, 02002 (2023)
GISCA 2022 and GI 2022
https://doi.org/10.1051/e3sconf/202338602002
