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The following conclusions can be drawn on the basis of the research:
With the increase in the differential of connected elements of friction coefficient decreases.When a drop of 3.0 mm revealed a marked decrease in coefficient of friction.
Gaps, with a difference of elements in compounds to 3.0 mm practically don't influence the coefficient of friction and these gaps can be sealed to prevent the ingress of moisture. Gaps greater than 3.0 mm is unacceptable. When you see these gaps it is recommended to fill them with additional plates, the thickness of which is equal to the value of the differential.
References:
1. Vaynblat B. M. High-strength bolts in the construction ofbridges. - M., - Transport, - 1971. - 166 p.
2. Bogdanov T. M. The compounds of metal structures on high-strength bolts. - Moscow, - Transjeldorizdat, - 1963. - 42 p.
3. Kozmin Y. G. Designing bridges and pipes.Metal bridges. - M.: Route, - 2005. - 460 p.
4. Lesokhin B. F. Experimental studies of bolt welded superstructure under load. In collection:.Research of steel and steel-concrete bridge spans. - M. - Transport, - 1970 - P. 164-182.
DOI: http://dx.doi.org/10.20534/ESR-16-9.10-191-193
Muradov Navruz, Research Institute of Irrigation and Water Problems E-mail: ilhom_makhmudov@mail.ru
Evaluation of the influence of meteorological factors on the aeration zone and the groundwater regime using Gis and Mike Sheimitating models
Abstract: As is known in the groundwater regime is influenced by precipitation, surface runoff and evaporation of soil moisture. In the arid climate for crop production in the initial phase of the plant the determining factor is the condition of aeration zone, which is determined by the level of groundwater. And in areas prone to soil salinity, groundwater regime is determined by the state of irrigated lands: the rise of level or increasing salinity pose a risk to soil salinity, soil salinity reduces the productivity of irrigated lands and irrigation water. Along with this assessment of groundwater regime, especially its state level under the influence of precipitation and runoff are difficult scientific problem. The solution of this important agricultural production is the subject of this Article.
Keywords: runoff, groundwater, aeration zone, ground water level, groundwater regime, atmospheric condensation, soil salinization.
Introduction. In areas with an arid climate with groundwater runoff determine the main conditions of crop production. In establishing mode of an irrigation plants, especially cotton, the state of groundwater determines the amount of water-supply via irrigation canals. And for soils affected by salt and in the presence of groundwater toxic salts, state groundwater determine the main conditions of plant life: a small distance from the ground surface leads to salinization and soil degradation, and causes a deep state of increased demand for irrigation water. Prediction of ground water regime is a scientific challenge. The challenge is caused by the presence of a variety of factors that affect the groundwater regime, the most influential of them are precipitation and runoff. At the same time on the groundwater regime has a significant impact the area where it is located, if the territory is located on the river valley, the factors which have an impact on the groundwater regime, more than the areas in the steppe zone, etc. In this regard, as the object of research established Chirchik river basin area in the Tashkent region of Uzbekistan [1]. As a subject of research determined primarily influence of precipitation in conjunction with other components of the water balance of a river basin in ground water areas.
Materials and methods. Object of research is the area of Chirchik river basin, where crop productions are carried out exclusively by irrigation. Therefore, prediction of the state of groundwater enhances the effectiveness of water management in the production of crops, especially of cotton [1; 2].
Figure 1. Topography of Chirchik River Basin (DEM by GIS)
Cotton for the mentioned area is the main crop and occupies more than 60% of the irrigated area of Syrdarya river basin. As the research methods defined the water-balance method of river basin, the method of unspecified filtering and interpolation method of climatic factors, developed by the authors ofthis article. Water balance equation of Chirchik river basin:
^^gw ^^ QChar+Ugam + QOhan + P QChinoz Quse ET E ^^char+Ugam
- Water Inflow to Chirchik River Basin from Ugam River and Char-vak reservoir
Section 10. Technical sciences
QOhan - Water Inflow to Chirchik River Basin from Akhangaran P - Precipitation
QChinoz - Water discharge in Chinaz station
Quse - Water use of Chirchik River Basin
ET - Total amount of evatranspiration
E - Total amount of soil evaporation
Qw - Ground water discharge and expenditure
The Richard's equation ofunsteady filtration ofwater:
(h №+iV
Where 0 - volumetric soil moisture; t - time, day; 5(h) - the rate of extraction of water by plant roots (evapotranspiration), sm 3/sm 3 day. q - the flow of soil moisture, sm/day; h - pressure soil moisture cm of water; z - vertical coordinate pointing upwards; K - coefficient of hydraulic conductivity (hydraulic conductivity) sm/day.
Interpolation method of the climatic factors: Values of the coordinates of hydro-meteorological stations positioned relative origin to Tashkent weather station in meters.
a
Figure 2
Figure 3. Thiessen Polygon Method in Scheme of creating an interpolation method for establishing climatic factors of Chirchik river basin, Figure 4. Layout stations in the Chirchik river basin by using Thiessen Polygon Method inArcGIS. Data network of observation wells Figure 5 by means of which monitored the status of groundwater.
Figure 3 Figure 4
The main part of the research. Using the parameters of the water balance Chirchik river basin, topographic maps using the program MIKESHE simulation model to get a map of seasonal changes in groundwater levels throughout the basin of Chirchik river (Figure 4).
Figure 5
Figure 5. Seasonal changes and distribution of rainfall in the catchment area of the river Chirchik in 2010 and Figure 6. Initial Ground water horizon, by using interpolation of the each ground water well.
Simulated results of the level of groundwater by using MIKE SHE simulation model of river basin balance.To establish the reli-
Figure 6
ability of the data on changes in groundwater levels calibrate the measured values of the groundwater level according to observation wells in the basin with the results obtained by the simulation model.
Calibration and comparison of the results obtained by natural observation and calculation method of feature points in the basin are shown in Fig. 7.
Table 1. - Initial data for the assessment of groundwater monitoring wells according and simulated results of the level of groundwater by using MIKE SHE simulation model of river basin balance
wells W03 W06 W09 W03 W06 W09
X/Y Coordinates 69.50517 69.26844 69.05472 69.50517 69.26844 69.05472
41.36778 41.30378 41.05992 41.36778 41.30378 41.05992
Altitude 519 461 244 519 461 244
GWL Ground Water level from the point of altitude (ob- Ground Water level from the point of altitude (Simu-
served data) lated results)
JAN 515.7 451.3 320.6 515.7 451.3 320.6
FEB 515.4 451 320.5 515.829 450.963 321.143
MARCH 516.1 451.1 320.6 515.821 450.936 321.289
APRIL 516.7 451.3 320.6 515.818 450.912 321.432
MAY 516.8 451.6 320.8 515.911 450.896 321.409
JUNE 516.9 451.7 320.8 516.012 450.961 321.362
JULY 517 452 320.8 516.06 451.039 321.311
AUG 517.1 452.1 320.7 516.076 451.082 321.267
SEPT 517 452.1 320.7 516.073 451.085 321.228
OCT 516.9 452.1 320.6 516.067 451.068 321.198
NOV 516.8 452 320.5 516.05 451.045 321.181
DEC 516.7 451.9 320.4 516.039 451.021 321.173
Figure 7. Calibration results of calculation methods with the results of measurements on the well 03
Fig. 7 the upper dark lines show the earth's surface, and the red and blue lines- groundwater levels, determined by different methods. As the graph shows the similarity values between forecast and actual values of groundwater level fluctuations within acceptable RMSE for W03 point is 0.65943, which makes permitted by applicable predictive calculation method for establishing groundwater level at any point in the river basin.
Conclusions. Developed earlier interpolation method of climatic parameters, contributed research to develop a method of
predicting the state and dynamics of changes in groundwater levels, the river basin. As a result, developed a model that allows you reliably to predict the state of the ground water level, the river basin.
Taking into consideration that groundwater together with irrigation water are sources of water use plants, prediction method can effectively manage water resources for irrigation of crops, especially cotton. Forecast for the groundwater level contributes to the adoption of scientific and technical measures to protect the irrigated land from waterlogging and salinity.
2.
References:
Makhmudov Kh., Mitani Y., Kusuda T., Interpolation of Climatic Parameters By Using Barycentric Coordinates, World Journal of Environmental Engineering, - 2015, - Vol. 3, - No. 1, 1-6.
Mahmudov I. E., Muradov N. "Evalution of the management and Use of Water Resources in the Middle Reaches of the Syrdarya Ba-sin'7/Science journal Trans Tech Publications, - 75-80, - 2016, - Switzerland.
