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Haydarov Safarboy Abdirashitovich, Khikmatov Fazliddin Khikmatovich, prof. dr., National University of Uzbekistan named after Mirzo Ulugbek, Tashkent city, Uzbekistan E-mail: haydarovsafarboy@gmail.com
STATISTIC EVALUATING THE INFLUENCE OF CLIMATIC FACTORS TO THE STREAM OF ZARAFSHAN RIVER
Abstract: The article analyzes the effects of climatic factors on the flow of the Zarafshanriver, including the temperature of winter and summer precipitation and the summer temperature. To this end, the Zarafshan River has identified a large number of interconnected climatic factors between the annual average water costs and its regression equations. It is recommended to use these equations for the practice of hydrological calculations.
Keywords: river, river flow, annual average water consumption, climatic factors, summer precipitation, winter precipitation, air temperature, multifunctional connection, statistical evaluation, equation of regression, hydrologi-cal calculations.
Introduction: Climatic factors, in particular, atmospheric precipitations and air temperature matter significantly on formation of streams of rivers in mountains of Central Asia. Researches put into practice by well-known scientists -V. L. Shuls, O. P. Sheglova, M. N. Bolshakov, G. E. Glazirin, V. E. Chub, F. Kh. Khikmatov and others show that influence of these factors to the stream of rivers changes appropriately to the height. Especially if stream of rivers placed in foothills and average heights associates with atmospheric precipitations in all respects, air temperature will influence powerful in rivers beginning from constant snow and glacier (7, 6, 2, 3, 4, 5). Nevertheless, problems by statistically estimating influence of climatic factors above mentioned on appearing of stream of mountain rivers weren't dealt exactly in hydrology. It should be noted that the solution of present problem has practical and scientific importance in hydrology of mountainous areas.
Main purpose of present research deals with discussing problem aforesaid in the example of Zarafshanriver which was considered trans-boundary, more precisely statistically evaluating influence of climatic factors (winter and summer atmospheric rains, air temperature in summer) onformation of stream of these rivers.
Data. We used average monthly and annual water expenditure measured at basin and climatic period (1961-1990 years) of Dupuli hydrological post of Zarafshanriver which selected as object of researchto achieve this goal as primary information. And also we used information about atmospheric precipitation and air temperature observed at meteorological stations such as Dekhauz, Shakhriston, Anzobpasss located in watershed of Zarafshanriver according to tasks planned in the research.
We used the way of objective equalization and normalization which suggested by G. A. Alekseev in statistical evaluation of many numerous connections between hydrometeo-
rologicalchanges in the research. It should be noted that the variables we selected are considered monotonic hydrological variables which comply with the requirements of G. A. Alek-seev's method.
Results and discussion.It is known from aforementioned that we base on following four hydrometeorological-variables in the research: 1) average annual water expenditures observed in the river; 2) winter atmospheric precipitations; 3) summer atmospheric precipitations 4) summer air temperature. Following three types of multiply calculations have been fulfilled considering that there are three (Dekhauz, Shakhristonpass, Anzobpass) basic meteorological stations:
XM^ (»VI-J^L K)Au3, (»vi J®ed],
= Mzx^ *xwJmахр, »VI-J^L Here: QAn - average annual water expenditures measured at Dupuli hydro post of Zarafshan river, »XXIII and »XIVIX - total combination of winter and summer precipitations observed at meteorological stations, (»tVI-IX)Oeg- total combination of average monthly air temperatures registered at meteorological station of Fedchenko glacier in June-September months.
Besides this, average values of information of the meteorological stations of Dekhauz, Anzob pass and Shakhriston belongs to this calculation period were taken and used them as special variables and following connection was estimated statistically:
Qn = №
QAyn = №
»x
'x-m' iv-IX^
VVT
■X-III' V-IX^
»X
'X-III'IV-IX^
Q, = f(»x
»X »
X-III'IV-IX' VI-IX-
),
Here: QAyn - average annual water expenditures, »Xx_m - and »XIVIX - average values of winter and summer precipitations measured at meteorological stations, »tVI-IX - total combination of average monthly air temperatures registered at meteorological station of Fedchenko glacier (table 1).
Section 4. Geography
Table 1. - Statistic indices of connections between climatic factors and average annual water expenditures of Zarafshan river
Type of connection ro ±^0 r02 ±^02 r03 ±^0,3
O-Ayu = ^IV-IxMe*, 0.68 ± 0.103 0.62 ± 0.114 0.21 ± 0.178 0.46 ± 0.146
Qyn = ./№x-„I, ZXIvJAнз, ^JM 0.49 ± 0.146 0.33 ± 0.165 0.21 ± 0.178 0.46 ± 0.146
Q^ = №Xx-„I, ZXwJWахр, (»VI-J^] 0.70 ± 0.098 0.56 ± 0.127 0.03 ± 0.186 0.46 ± 0.146
0Ayn = f(»XX-III, »XIV-IX, »tVI-IX) 0.69 ± 0.101 0.65 ± 0.107 0.15 ± 0.182 0.46 ± 0.146
Note: r ± a
0 70
and its errors.
- coefficient of total correlation and its error, r01 ± ®r0
r02 ±^02,
r03 ±or - coefficients of double correlation
1. As showed at the schedule, values of coefficients of total correlation express connections between hydrometereologi-cal variables change between 0.49 ± 0.146 ^ 0.70 ± 0.098. It should be noted that values of coefficients of total correlation express their density in the connections of types 1, 3, 4 are almost the same. But value of coefficients of total correlation in connection type 2 is very little, that's equal to 0.49. The reason of this, as above mentioned, atmosphere precipitations measured at metereological station of Anzob pass are not representative for Zarafshanriver.
Coefficients of double correlation, that's r and r02, appropriately, represent links between water expenditure (QAyn) andwinter (XX_m) andsummer (^IV_IX) atmosphere precipitations. The table shows that values of r , between 0.33 ^ 0.65, values of r02 change between 0.03 ^ 0.21. Present results show that winter rains in the links of types 1, 3, 4 have an important role on appearing of stream of Zarafshan river. The smallest value (0.33) taken in the results of calculations belongs to Anzob pass, as aforementioned, this shows that there is little importance ofwinter precipitations registered at this metereological station on appearing of stream of Zarafshan river.
Values of coefficients of double correlation r02represent link between stream of Zarafshan river and summer precipitations change in very small values, exactly between 0.03 ^ 0.21. Contribution of summer precipitations on formation of stream of Zarafshan river is very low.
Influence of air temperature is reflected at value r03of coefficient of double correlation on formation of stream of river. Because we used only metereological station, exactly, infor-
mation of metereological station "Fedchenko glacier" on all types of calculations.
It can be said that based on statistic calculation above mentioned and analysis of their results, winter atmosphere precipitations and influence of summer air temperature exert effectively on appearing of stream of Zarafshan river. That's why amount of atmospheric precipitations on Zarafshon basin during cold half of a year and change of summer air temperature on Zarafshan basin between years are reflected on vibrations of average annual amounts of river stream.
Conclusions
1. Zarafshan river basin has its special orographical features and this factor exerts to variables at different values by height of amount of atmospheric precipitations on basin and by area located river basin to the distribution at various amounts;
2. Annual stream of Zarafshan river and climatic factors, exactly atmospheric precipitations and air temperature were considered statistic indications of multiply links to estimate their impact. Argument 3 on calculations, paying attention to air temperature provided to increase coefficient of total correlation, even at very small values;
3. Average annual water expenditure of Zarafshan river and summer atmospheric precipitations and also regressive equations of multiply links between summer air temperature were composed. The exactness of types 1, 3, 4 of these equations exactness were estimated with coefficients of total correlation between 0.68 ^ 0.70. It is recommended using them in practice of hydrological calculations.
References:
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2. Bolshakov M. N. Water resources of the rivers of the Soviet Tian-shan and methods of their calculation.- Frunze: Ilim,-1974.- 306 p. (In Russian).
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4. Chub V E. Climate change and its impact on hydrometeorological processes, agroclimatic and water resources of the Republic of Uzbekistan.- Tashkent: Publishing house VORIS - NASHRIYOT,- 2007.- 132 p. (In Russian).
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