May 1, 2013 - In contrast to the majority of other regions of Russia, the. Republic of Sakha (Yakutia) possesses enormous reserves of renewable hydrologic ...
Power Technology and Engineering
Vol. 47, No. 1, May, 2013
HYDROTECHNICAL CONSTRUCTION HYDROLOGICAL-HYDROCHEMICAL REGIME OF THE TIMPTON RIVER BASED ON DATA OF ECOLOGIC-ENGINEERING SURVEYS FOR DESIGN OF THE KANKUNSKAYA HPP D. D. Nogovitsyn,1 N. A. Nikolaeva,1 and D. D. Pinigin1 Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 11, November 2012, pp. 8 – 13.
Basic data derived from ecologic-engineering surveys for investigation of the present-day hydrologicalhydrochemical regime of the Timpton River are presented. Keywords: Timpton River; preconstruction status; ecologic-engineering surveys; hydrological and hydrochemical characteristics.
requisite step for all survey operations. In this connection, ecologic-engineering surveys were conducted in the summer of 2010 to investigate the present-day hydrochemical condition of the Timpton River and its tributaries, which include hydraulic sampling of water and bottom deposits, and subsequent analysis under laboratory conditions, as well as analysis of the results obtained. Hydrologic characteristics of Timpton River. The Timpton River is 644 km long, and has a watershed area of 44,400 km2. The source of the river resides on the northern slopes of the Stanovoy Range. In its upper reaches, the Timpton flows from west to east, and then to the north, and changes direction to the northeast from the mouth of the Chul’man River. The main right tributaries are the Kabakta, Ulakhan Melemken, Pravyi Oyumrak, and Nel’gyuu Rivers, and the left tributaries the Iengra, Gorbyllakh, and Khatymi Rivers. The Timpton River is classed as a river with a mixed type of supply of which formation of annual maxima both during periods of the spring flood, and passage of precipitation-induced high water in the summer is characteristic. The spring rise in the water level begins at the end of April — from the first days of April and through the first days of May, and thereafter the rise is rather rapid. Maximum high-water levels are noted on average in the last days of May after the river has been cleared of ice. Cessation of high water is confined to mid-June. During the summer, it is possible to observe the formation of up to 8 – 12 rain-induced floods, the majority of which have complex multiple-peak comb-like hydrographs. The rate of the rise in levels of the most significant floods ex-
In contrast to the majority of other regions of Russia, the Republic of Sakha (Yakutia) possesses enormous reserves of renewable hydrologic energy in its rivers; this has dictated the design and possible construction of a grandiose Southern Yakutia hydroelectric complex, which is required for continuing development of the industrial and social infrastructure of the entire Far-Eastern region of the country. The design of the Kankunskaya HPP on the Timpton River with an installed capacity of 1200 MW and mean-annual electricpower generation of up to 4.7 billion kW · h is currently being completed. As with any human-induced intervention, construction of the Kankunskaya HPP and impoundment of a reservoir will, by itself, inevitably involve various changes to northern natural complexes, which for the most part will be negative, and may have serious ecological consequences. During construction and functioning of the reservoir impounded for the Kankunskaya HPP, all elements of the natural environment — water, air, hydrogeologic, and biotic media — will inevitably be subjected to change as a result of redistribution of runoff, flooding, and underflooding. Here, the qualitative condition of the water in the reservoir during the impoundment of which the valleys of the Timpton River and its tributaries, and also the slopes bordering the valley, which are covered primarily leafy vegetation to an elevation of 608 m, will be flooded, will assume major practical significance. This investigation of the “zero” status of the natural environment, i.e., its status prior to the start of construction, is a 1
V. P. Larionov Institute of Physico-Technical Problems of the North, Siberian Division of the Russian Academy of Sciences, Yakutsk, Russia.
1 1570-145X/13/4701-0001 © 2013 Springer Science + Business Media New York
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D. D. Nogovitsyn et al.
ceeds the rate of the rise during the period of high water (up to 1.5 – 2.0 m/day) [1]. Summer maxima are passed on average by the close of July – August. The summer low-water period is weakly expressed, or entirely absent, while the winter low-water period continues for approximately half a year and coincides with the period of stabile ice on the open water. The temperature of the water is rather low, even in the summer (no higher than 10°C), and only in July may increase to 18 – 20°C. In October, it is observed to drop to tenths of a degree, resulting in the appearance of the first ice formations at the beginning October. Autumn ice movement continues for 15 – 20 days on average in the middle and lower reaches of the river [1]. Development of stable ice begins at the end of October. The most rapid increase in the thickness of the ice cover, as on the other rivers of Yakutia, is observed in the first half of the winter (0.5 – 1.0 cm/day), while it goes virtually unnoticed in March – April. During the winter, the maximum thickness of the ice is 60 – 80 cm, increasing in individual years to 80 – 110 cm. Spring ice movement begins at the outset of the second decade in May, and continues on average for 8 – 10 days. During the breakup period, ice jams may form on the river: in 63 and 94% of the cases at the village of Ust’-Baralas and the city of Ust’-Timpton, respectively. The ice jams are of short duration (from one to two days). Despite the fact that additional rises in the levels range from 130 to 270 cm (up to 500 cm in individual years) during formation of jams, maximum water levels during spring ice phenomena are 2 – 3 m lower than the maxima when the channel is free of ice. The river is referred to as a zone of increased flow with negligible variability (Table 1). Comparison of runoff characteristics observed at the Ust’-Baralas and Ust’-Timpton hydrological stations indicated their close relationship (r = 0.88 – 0.90); this indicates synchronicity of fluctuations in the lateral influx and runoff of the basic river. Multiyear characteristics of seasonal and annual runoff at the observation stations differ by 13%, and the seasonal distribution of runoff is approximately similar; intrayear flow distribution is therefore calculated based on data for the closing site of the Ust’-Timpton hydrological station, which are borrowed from [1]. Intrayear runoff distribution differs negligibly in years characteristic with respect to water content.
Extreme nonuniformity of intrayear runoff distribution is characteristic of the Timpton River, and its low values are noted during the winter and high values during the warm period. In the spring-summer season, the annual runoff is normalized as approximately 95%, and 3 – 5% is arrived at for the fall, and 0.8 – 2.3% for the winter (November – April). The Timpton River basin is referred to as a group of rivers in the region of Yakutia, for which maximum flow rates in different years are observed in both the period of the spring flood, and also during summer high water; the number of these summers is similar on average. Here, however, the highest flow rates usually belong to the summer rain-induced high waters. The layer of the spring runoff over the area of the basin varies little and is 250 – 300 mm (high-runoff zone). The coefficients of its variation range from 0.20 to 0.25, and decrease with increasing runoff area. Lowest summer flow rates may be observed in any of the months of low summer water, which is usually short-lived. The overall duration of the low-water period is 30 – 40 days on average. The runoff during the lowest continuous lowwater period with a duration 30 days is the basic computed minimum-runoff characteristic. The duration of the winter low-water period is, on average, 200 days, the layer of runoff is 20 mm, the absolute values of the runoff range from 0.10 to 0.20 liter/(sec · km2), and the average minimum flow rate of water is 3 – 5 m3/sec. A broad expanse of difficult-to-erode rocks is characteristic of the Timpton River Basin; on average, therefore, turbidity values do not exceed 25 g/m3. Variation in water turbidity is primarily synchronous with the variation in the river’s water content. Turbidity increases sharply during the passage of rain-induced high water (up to 200 – 250 g/m3). Intrayear distribution of detritus flow is comparatively stable over a period of many years. The highest mean-monthly flow rates of detritus are observed in June (40 – 50% of the annual flow). The basic part of their annual volume is passed during the spring-summer (99%), and is insignificantly low in the other periods. Hydrochemical characteristic. In the Timpton River Basin, monitoring hydrologic observations are carried out at the only station in the grid of the Yakutsk Administration, Federal Agency for hydrometeorology and environmental monitoring — the Ust’-Baralas hydrological station. Generally, no systematic observations of the hydrochemical status of the water are made.
TABLE 1. Value and Variability of Annual Timpton River Flow Key Station Nagornyi station Ust’-Baralas hydrological station Kankunskaya HPP Ust’-Timpton hydrological station
Distance from mouth, km
Watershed area, km2
595 337 214 20
613 13,300 27,300 43,700
Value and variability of annual flow Q,
m3/sec 9.35 186 360 536
Mo, liters/(sec · km2)
Cv
15.2 14.0 13.2 12.3
0.28 0.22 0.22 0.0
Hydrological-Hydrochemical Regime of the Timpton River
Sampling of water for hydrochemical analysis was conducted in conformity with requirements of GOST R 51592–2000 “Water. General requirements for sampling,” which was introduced on 1 July 2001 by decree No. 117 issued by the Gosstandart of the Russian Federation on 21 April 2001. Bottom deposits were extracted in accordance with GOST 17.1.5.01–80. The samples were stored in conformity with GOST 17.1.5–85. They were transported in plastic and glass containers, assuring their preservation. Chemical analysis of the water and bottom deposits was carried out in chemical laboratories run by the Aldan Specialized Inspection Agency for State Ecological Monitoring and Analysis, Hydrologic Administration “RIATsEM” and the Republican Analytical Inspection Agency, Hydrological Administration “RIATsEM,” as well as by the FUUZ “Center for Hygiene and Epidemiology in the Republic of Sakha (Yakutia)” in conformity with standard procedures. The section of the Timpton River Basin from the village of Chul’man to the tailrace of the Kankunskaya HPP, which includes the following tributaries, was the subject of investigation: Gorbyllakh, Chul’man, Chul’makan, Ochchugui Melemken, Oyumrak, Khatymi, Kigomok, Atyr, Kurung-Khoonku, Anamdyak, and Nel’gyuu. Water samples were recovered for quantitative chemical analysis, and determination of the content of oil products, heavy metals, and mercury, while samples of bottom deposits were taken for chemical and radiological analysis. The chemical composition of the water samples and bottom deposits were analysed on the basis of laboratory determinations, and an evaluation of the present-day hydrochemical status of the water in the Timpton River and its tributaries was made on the basis of this analysis. Since the Timpton River is currently classed as a piscicultural water body, the limiting allowable concentrations of harmful substances for the water in water bodies of piscicultural significance were used for comparative analysis. Mineralization of water. The waters that are formed directly on the surface of the watershed are the primary feed source of the Timpton River. On the whole, mineralization of the water in the water courses inspected is lower than, and far from maximum permissible standards (1000 mg/dm3). Based on analytical investigations of a single sampling of the Timpton River and its tributaries during the summer of 2010, mineralization basically does not exceed 100 mg/m3, and ranges, on average, from 60 to 70 gm/m3 when the overall maximum permissible concentration (MPC) is 1000 – 1500 mg/dm3 and the MPCpc 1000 mg/dm3. Mineralization over and above 100 mg/m3 is noted only in certain of its tributaries (at the mouth of the Atyr River, the dry residue is 110 mg/dm3). The salt composition of the water essentially varies little in all sections of the river. In terms of amount of suspended matter, the water in all samples taken exceeds the MPC by a factor of 12. The MPCpc = 0.25 mg/dm3.
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In the ionic composition of the Timpton River water, the hydrocarbonate ion is predominant (up to 32.9 mg/dm3), and only in the region of the backwater and above the mouth of the Chul’man River does the sulfate-ion predominate (up to 17.2 mg/dm3) where the MPCpc = 100 mg/dm3. The sulfate ion is also predominant in the waters of several tributaries (Khatymi, Atyr, Kurung-Khonku, and Ochchugui Melemken Rivers); this is possibly associated with the influx of ground water. The content chlorides in all water samples is lower than 3 mg/dm3 where the MPCpc = 300 mg/dm3. The content of other salts (sodium, potassium) is also much lower than the maximum permissible values. The fluoride-ion content is also found to be significantly lower than the MPC (approximately 0.1 – 0.2 mg/m3 where the MPC = 1.5 and MPCpc = 0.75). According to Alekin [2], the water of Timpton River is very soft, and its hardness does not exceed 0.7 mg-eq./dm3 and in individual cases, the hardness factors are 1.5 mgeq./dm3 (mouth of the Atyr River), and 2.5 mg-eq./dm3 (mouth of the Ochchugui Melemkan River), which correspond to soft water. The water of the river is neutral, and the pH falls within the range from 6.5 to 7.5; this corresponds to the MPC for water bodies of piscicultural significance. In terms of gaseous composition, the water of the rivers is in full compliance with requirements set forth by standards governing water bodies of piscicultural import. The oxygen regime of the water course is satisfactory: the content of carbon dioxide ranges from 20 to 30 mg/dm3, while dissolved oxygen (more than 10 mg/dm3 in all samples) is lower than the limit of observation by the determining method, and lower than its average concentrations in rivers and lakes. The carbon dioxide concentration (especially in the near-bottom layer of water) characterizes the oxidation processes (decomposition) of organic matter, which occur directly in the water, and also in soils and slimes with which the water comes in contact. Biogenic substances. The biologic productivity of a water body, like the quality of the water, will depend to a large degree on the content of biogenic and organic substances, the presence of which is determined by the activity of bacteria and phytoplankton, and through them, also other water organisms. Their number is determined by the river flow and surface runoff, and also by the processes that take place within the water body. In the water of the water courses inspected, the effect of these factors on the dynamics of biogenic substances is negligible; this is most likely explained by weak growth of phytoplankton. The basic role in the formation of reserves of biogenic substances therefore belongs to the hydrological regime of the rivers. Ammonium nitrogen. An increase (2.88 MPCpc) content of ammonium nitrogen is noted in one of the samples collected in the upper reaches of the Timpton River, indicating a certain degradation of the sanitary condition of the water course in this section. For all other collection points on the river and its tributaries, and also the inspected tributaries
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of the Aldan River (Malyi Nimnyr and Orto Sala Rivers), the indicators are lower than the MPC for water bodies of piscicultural significance, which is 0.5 mg/dm3. Nitrites. In natural waters, these compounds are extremely unstable, and are encountered in insignificant amounts in the surface layers when conditions are favorable for oxidation. The existence of nitrites is associated primarily with mineralization of organic matter and nitrification. Their increased content indicates contamination of the water body. The distribution and variation in nitrite concentration therefore serve as indicators of the quality evaluation of the water and processes of its self-purification. Based on all water courses, the nitrite-ion concentrations where the MPCpc = 0.08 mg/dm3 are insignificant (
