Calculation of characteristics of spring drain of the Eastern part of the Caspian Region

The results of the calculation of the spring runoff layer and maximum discharge of the eastern tributaries of the Ural River are presented. The characteristics of the runoff are given in a multiyear period and the statistical parameters are determined for three periods. The estimation of the accuracy of the calculation of the parameters of the annual flow.

Keywords: spring runoff layer, maximum runoff, regression equation, analogy method, statistical parameters.

The Ural River is one of the rivers that mainly feeds on melt water. The annual flow consists of 70-80 % of the spring flow of the river. At this time, the water level rises to 2-2.5 meters. The main feature of the Urals is the high variability of runoff. The total flow of the Urals can be several times more in a high-water year than in a dry one.

The main source of spring floods in the rivers of this valley, as well as in other parts of Kazakhstan, is the snow reserve of the river basin. The snow cover of the region, from north to south and west from the east, is the source of the main rivers of the region. Snow cover falls on the territory of the Ural-Caspian basin at different times: in the south, usually in mid-March, in the south, in the north — in the first decade of April. The rivers on the east coast of the Ural River are Sholanatyrskaya, Kuperanatskaya, Auckland, Shidertiyskaya, Buldyrty-Karagashskaya, Bulreddi-Abay, Shilili, Kaldygai zogons. Depending on the location of the rivers, the cover is characterized by surface characteristics. Characteristics of river flow were studied in the 70s of the last century. This information needs to be clarified, taking into account the recent monitoring data from 1965, taking into account the impact of climate change on farms in the array. Therefore, since data for the last 30-35 years are ignored, it is necessary to bring the flow characteristics to a long-term perspective.

Baseline data and research results. The calculation period was determined to determine the statistical characteristics of the spring flow of the Ural River. The year 1940-2015 was calculated as a calculated integral curve for the spring layer of the flow of these eight stations on the right bank of the Ural River.

In this paper, the reconstruction of the annual flow using the analog method was performed using the regression equation. Analog rivers were selected in accordance with the requirements, and the RCR> was performed under the condition of 0.70 [3,4] (Fig. 2). Thus, the values ​​of R at the points of the Szolakanaty-svh.Ankatinsky, Kuperanaty-Algabas, Olenty-s. Dzhambeyty, Shiderty-svkh. 0.77-0.95 (Table 1).

Fig. 1. A graph of the relationship between a — a layer of spring flow and average annual water flow h = f (Qav), b — maximum flow and a layer of spring flow Qmax = f (h)

For a quantitative assessment of the effectiveness of bringing the flow rate to a multi-year period, an efficiency indicator K is used. [3]:

where R is the pair correlation coefficient, n is the number of years of joint observation. The efficiency indicator characterizes the percentage reduction in the average when bringing the series to the period N.

The indicator of the effectiveness of bringing the coefficient of variation to a multi-year period is determined by the same formula

. 100 % (2)

The efficiency index K characterizes the percentage reduction in the average error and the coefficient of variation when a series is brought to a multi-year period.

According to the results of calculations, the efficiency indicator of the flow rate is 97-76 %, the coefficient of variation is 77-56 %.

Because of the abstraction of water for the needs of various sectors of the economy since 1974, the flow of the southern tributaries of the Ural River is considered to be regulated [1]. Therefore, the characteristics of the spring runoff are defined in three variants: according to the data of actual observations, for a long-term period of 1940-2015, and for the last forty-year period from 1974 to 2015. The results of the calculation of the characteristics of the spring flow of the Ural River by three points are presented in tables 1 and 2.

Table 1

Table 2

Characteristics of the spring flow layer of the eastern tributaries of the Ural River

Characteristics of the spring flow layer of the eastern tributaries of the Ural River those. 38.9 % and 24.8 % respectively. The spring runoff layer of the Shirdirti-Dzhambeytinsky and Buldyrty-Karagash pillars was 36.6 mm and 27.9 mm in 1940-1974. And it was 27.5 mm and 24.7 mm in 1975-2015, i.e. 18.1 % and 11.5 % change. And as Kaldygayty-Zhigerlen, there was an increase of 24.3 percent in 1940-1974, from 22.7 mm in 1975 to 30 millimeters.

The long-term average values of the maximum water volume at the Buldyrty-Abai station were 29.8 m3 / h in 1940–1974 and 17.4 m3 / s in 1975–2015. For the usual natural period (1940-2015). The value of the long-term average annual output was 23.14 m3 / s. The Sholakanats-Ankatinsky were at the natural stage (1940–1974) with a maximum transformation of 52.0 m3 / s and 40.0 m3 / s in the usual natural phase (1975–2015). The average peak annual peak value of 1940-2015. It is 45.5 m3 / h.

At the same time, the average annual maximum traffic intensity at the station Kumerkanata-Algabas was 123.1 %, and the average annual maximum annual traffic intensity increased by 56 % over the years 1975-2015. If we are talking about the annual peak of the annual peak of Olenta-Jambeita and Shidrathi-Jambeita (1940-2015), we can see that it is 164.8 m3 / s and 85 m3 / h, and the average annual long-term average is 8.7 % . on the contrary, by 39.6 %. If we calculate Kaldygayty-Zhigerlen and Buldyrty-Karagash, we will see that the long-term average annual maximum (1940–2015) increased to 266 m3 / s and 56 m3 / h by 20.15 %, and also decreased by 12.2 %

Findings. Thus, the control data of eight stations in the eastern part of the Ural River and the long-term characteristics of the average peak and spring runoff were used to perform restoration work. Characteristics were determined at different stages, taking into account the volume of natural and restored runoff.

As a result, after 1975 there was a significant decrease in the volumes of maximum water discharge and spring runoff. The only reason for this decline is that since the 1970s, intensive construction of reservoirs, development of production capacity and high demand for farm water resources.

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