Chemistry

И И ИЧ И И И А И А И ИЩ ихи 2- И - А К А ё ё . . , ё , , - а ев И. .2, Ши . .1, 1 ва . . , Жа еев . .1 . .1, а 1-И А А – , , , . , , . , 1500-3500 , ., , - ( ., ). , , , , . . 1. ( ) . . , . - ё – . . 1. , I – II 3 III / (Г IV … 1985; V 9.96 9.06 9.32 23.9 60 5.49 4.98 4.9 – … 1969; VI VII VIII IX 78.8 57.8 33 20 X XI … 1967). XII 15.2 13.3 11.4 28.6 10.5 31.7 56.8 43.6 22.2 11.1 7.8 6.55 5.82 17.6 3.11 3.11 3.28 8.49 22.2 38.1 23.1 8.67 4.41 4.1 3.83 3.32 10.3 136 175 136 152 261 511 819 711 120 504 286 207 147 324 . 1, . ё . 1. . 800–1000 85 % . 3 / , - . 90 800 80 700 70 600 60 500 50 , 400 40 300 30 200 20 100 10 0 -Ах Н , 3 / , 3 / 900 ,Ч ч . 0 1 2 3 4 5 6 7 8 9 10 11 12 Месяц -Н - -Ах -Ч ч ; ; - ; .1. . . - , , . , . . , , . , , – – – ., 1994): , , – ( , , . 121 1954 . ( . 2). . 2. . . ( . 4.06.1954 . / - ) 18.05.1954 . %- . / 18.06.1954 . %- . / %- . : Na+ + K+ 16.5 23 19.0 18 12.8 14 Mg2+ 7.8 22 21.3 42 11.2 26 Ca2+ 32.2 55 34.1 40 42.1 60 : – 5.1 5 14.3 10 9.8 8 SO42– 18.3 13 41.1 20 47.7 28 HCO3– 146.5 82 180.1 70 135.5 64 Cl 153.0 .2 219.6 , 198.3 « ( » . ) , . 530 45 . , « » ( . « 150 ) , » , « - » , « ». , . , , . . 3 324 / , ( 1973 1974 - ) . , ( . – 0,47 / 3 …, 1979). . , , - , ё ( ., 1979). . , . 122 , . . , .3 ., 1964) ( .2 1987-1990 30 % » « 1951-1955 . . . 3. . « ( Na+ + K+ %/ . - 14.5 23.3 « 6.4 »). 19.6 30.8 57.1 5.9 6.3 , / 25.2 24.8 14.0 26.4 43.2 48.8 9.4 5.9 48.1 22.6 194.2 71.5 237.0 14.3 22.6 7.9 24.2 29.3 53.2 6.1 6.3 31.6 24.1 115.8 69.6 146.1 17.1 23.4 8.6 22.5 34.8 54.1 8.3 11.3 36.8 24.0 125.8 64.7 168.5 / . 250 ) ) 140 200 120 100 150 80 100 60 40 50 20 0 ) – 1951-1955; ) – ; – .) TDS HCO3 SO4 Cl – 1987-1990 ; – . 1951-1955 1987-1990 ( Ca Mg Na + K TDS HCO3 SO4 Cl Ca Mg Na + K 0 . 2. ( 3 143.5 160 , HCO3– %/ . 24.2 18.5 124.0 75.2 1987-1990 - SO42– %/ . Ca2+ Cl– %/ %/ . . 1951-1955 . Mg2+ %/ . » « » 1987-1990 К ). 123 . , , , + , (23 %), 1-3 %. (5 %), , , , (7 %), . 40-50 , 40-50 ( (19 %), . . ) . . , - , . . , – « « - » ( . - - » ) .4 . 4. « - . » * « - » 1987 . - , % 7.20–8.12 7.67 7.42–8.02 7.85 +2.7 Cl– 7.1–41.8 18.2 5.13–17.7 12.2 –32 SO42– 30.3–92.2 48.3 26.9–72.0 43.0 –11 Mg2+ 6.1–18.5 12.0 10.6–20.3 12.5 +4.1 Ca2+ 29.6–63.1 44.1 20.0–48.1 39.6 –26 130–328 215 136–239 219 +2 , / . , 3 / 479.61 *– , – . . 4, . . , , , . 124 , , , . , , . 2007-2009 » ( . « - . 5, 5a, 6). . 5. . 2007-2009 « - » . / 3 . / , , Mg2+ Na+ K+ Cl– SO42– HCO3– NO3– 48 13 16 1.8 18 64.6 134 3 ё 2+ 20.08.07 426.00 334 3.5 7.8 0.16 27.08.07 303.00 315 3.3 8 1.52 44 13 15 1.8 16 65 122 4 03.09.07 303.00 321 3.3 8 0.56 44 13 15.4 1.8 18 65.8 125 4 10.09.07 303.00 334 3.5 7.8 1.36 47 14 16 1.8 16 63.8 140 1 17.09.07 303.00 367 3.8 7.8 1.04 54 13 15.6 1.8 7 10.3 126 1 24.09.07 209.00 329 3.3 7.9 0.24 58 12 16 1.8 18 62.6 134 3 19.04.08 198.00 379 4.4 7.9 0.56 58 18 29.6 2.4 37 97.5 168 2.7 27.09.09 250.00 375 3.8 7.6 0.48 61 9 21 2.1 16 67.9 171 3.5 . 5a. . « - » 1954–2009 . 1987 7.7 1990 7.6 1991 1992 pH 1954 7.7 2007 7.8 2008 7.9 2009 7.6 Ca2+ 34.1 44.1 39.7 38.5 44.0 47.0 58.0 61 Mg2+ 21.3 12.0 11.4 13.6 17.2 14.0 18.0 9.0 Cl– 14.3 18.2 16.0 37.0 16 SO42– 41.1 48.1 52.2 64.9 72.4 63.8 97.0 67.9 465.15 479.61 414.73 339.29 382.64 312.00 289.00 . , 3 / 125 . 6. . « - » 2007–2009 Cl–, / 18.0 SO42–, / 62.6 HCO3–, / 134.0 29.6 37.0 97.53 168.0 15.0 20.0 26.0 73.25 149.0 3.85 61.0 9.0 21.0 16.0 67.9 171.0 2.8 2007 57.5 39.1 13.5 12.8 23.5 0.46 24.3 5.0 75.3 51.85 156 101.3 3.3 1.5 2008 53.1 10.94 3.45 11.94 65.43 122.0 3.2 2009 64.13 9.73 1.13 5.6 71.6 141.5 4.0 2009 61.0 9.0 21.0 16.0 67.9 171.0 2.8 2007 54.3 54.1 10.6 3.65 6.5 13.1 9.6 6.67 64.2 58.8 134 1.128 2.9 1.3 2008 60.12 2.43 18.63 13.55 76.95 120.8 3.55 2009 52.1 23.1 7.98 10.38 83.12 170.8 4.5 2009 44.89 15.56 13.36 12.07 64.61 107.36 2.1 2007 52.8 44.1 11.2 13.62 13.3 0.39 10.7 10.0 70.9 49.5 100 115.9 2.9 3.32 2008 48.09 10.9 11.67 8.07 49.4 158.6 3.3 2009 45.09 14.2 30.64 7.34 82.3 164.7 3.42 2009 38.08 21.89 0.9 6.67 51.4 148.8 3.7 2007 43.8 48.1 15.2 8.76 10.9 1.89 8.0 8.34 58.2 50.6 147 109.8 3.4 3.12 2008 18.1 10.94 7.36 11.3 72.0 109.8 3.3 2009 50.0 15.8 18.1 5.47 79.4 158.6 3.8 2009 44.09 12.16 13.59 8.67 45.7 152.5 3.2 40.1 11.9 10.2 8.4 61.9 133 3.4 2+ Na+, / 2007 / 58.0 Mg2+, / 12.0 2008 58.0 18.0 2009 53.0 2009 , . , « - » . 3.3 * * * * * - . . 6. . « 126 - » 1954–2009 . . , (NaCl), (MgNa2(SO4)2 * 4 H2O) ( (Na2SO4) 1985). (Na2SO4 * 10 H2O), ., 1964; , 1972, , . , , , , ( ( , . 4) . 7). . M ≈ 267-302 / - я . 3. 3 . Ш . . 7. . 1 3) F 55 <0.3 0.54 0.12 28360 12000 40 0.04 0.7 1.1 38230 225 320.6 2822 163956 17000 90 <0.3 0.43 0.2 30174 0 215 300.6 2533 159525 19000 45 <0.3 0.44 0.11 29885 0 185 460.9 3678 132938 24300 70 <0.3 < 0.5 < 0.5 60.1 80.2 4.7 4.1 235 1,2 , 10 / NO3N Ca - 2009 . ( Mg Cl SO4 280.6 2364 177250 15500 18.3 340.7 627.1 Mn F 0,5 . . 20.5 4.8 24.8 60.3 96 225 26700 0 0.04 0.02 0.32 390 0.03 0.197 0.51 714 , 0.22 0.27 . , . , 127 30029 0 . , , . , - , . , . . – . . 100 – , / . , - , . , S = 11.5 , . 7, , 12×109 ε = 50- , 3 / 2 . 292 / 3 . , . , , . . . . 8. . 8. , . . ( - ) . 11500000 2 , . / , , / 0.05 . - 292 3 , 3 575000 / , 167900 000 / , 3 / 324 , , 3 0.1 115000 0 335800 000 - 3 / 28.6 17.6 380.5 11967912000 / , , 3 , 850 771500 0000 0.64 900 195480 00000 1.63 , / 3 0.022 0.017 , / 3 0.009 0.011 128 10.3 , ( 10-20 / 3 . 8), . , , « « « » , » . » 2007-2008 . 3 « » 30-60 3 / . , . 2007-2008 ., . 2008-2009 . , . ( , . 8). , . , 2008-2009 . , , 6-9 Concentration of species, mg/l 0 20 40 0 50 100 60 80 100 120 150 200 250 300 0 5 10 15 Deep, m 20 25 30 35 40 45 50 TDS, mg/l – Ca, – Mg, – Cl, – SO4, – NO3, . 4. 6-9 129 – TDS, mg/l я я я 2009 . 2009 . ( . . 4). . , 60 - , , / , 30- . . , , . . . ( ., 1972, . , M = 1-4 / 3 ( ., 1988). kf = 0.3-0.5 / . . - . 9), , . 9. , , / . - . ё ё . - « » Ca Mg Na Cl SO4 HCO3 25.10.1986 18.04.2008 26.09.2009 15.04.2008 946 1774 1298 1231 78 109 103 152 57 78 73 26 220 310 203 135 72 525 533 69 266 397 96 491 42 156 146 226 19.04.2008 515 78 19 16 12 87 244 28.04.2009 30.08.1969 19.04.2008 28.09.2009 17.04.2008 28.09.2009 490 410 476 458 472 375 81 52 44 41 70 63 17 8 9 9 13 10 15 44 62 68 27 17 10 18 21 21 25 22 77 61 103 98 49 32 247 177 174 171 241 196 18.04.2008 301 52 7 9 5 20 174 28.09.2009 02.11.2009 16.04.2008 27.09.2009 280 222 1220 1234 52 38 152 152 7 12 26 25 6 134 48 7 4 69 60 20 8 485 478 165 144 223 268 . .7 9 . 10. , . , , ( / . . 5). 130 . 100. . Ca 1 0,91 0,85 0,96 0,92 0,85 Ca Mg Cl SO4 NO3 TDS . 5. Г M Mg Cl SO4 N NO3 TDS 1 0,,96 0,,98 0,,95 0,,97 1 0,93 0,93 1,00 1 0,95 0,94 1 00,93 1 я я я . TDS < 1 / . - . 11. r = 0,37 . 11 , rCl-SO4 = 0.98, TDS, p < 0,0 05. rTDS-Cl = 0.97, TDS, - . 131 , rTDS-- SO4 = 0.98. . . 11. TD DS < 1 / Ca Mg SO44 Cl 3. N NO3 C Ca 1 M Mg 0,12* 1 C Cl 0,499 0,09 1 S SO4 0,511 0,14 0,98 1 N NO3 0,155 0,36 0,54 0,588 1 T TDS 0,488 0,20 0,97 0,988 0,63 *– p < 0,005 1 r = 0,37 TDS < 1 / , . 6. Г TDS , я я я TD DS < 1 / 132 3 . 6. 6 я . Cl-Ca, SO4-Ca, TDS-Ca . Ca-Mg, NO3-Ca, NO3-Mg, NO3-Cl , / , NO3-SO4. - . « Cl-Ca, SO4-Ca, TDS-Ca , ». , , Cl SO4 . Cl SO4 . , . . , - . – . 20 – 60 / , / . . , , . , . : , . , , , , , 80- . – , и ер . р . ., . ., .– . . »- « , 21, № 2, 1994. – . 144- 153. . ., ., XI, .– , 1985.–276 . . ».– № 21 « : // , 1964.– 95 . . . // . .– . 6. , 1972.– . 118–125. . . .– .– 53. 133 : // , 1985.– .: . . 40– 6. ./ . . ., . ., . . . – .: , 1979.– 214 . 1979 . . , 1979. - 224 . . . 1969-1971 . .– .: , , .– . . . .14./ : .– , 1972. .: , 1969. – 438 . ( , . ., 14, ) / . 1.– . - , 1967. . . . 1984-1988 . - .– 140 . 134 : , , 1988.– HYDROCHEMICAL CONDITIONS OF WATER COMPOSITION FORMATION IN THE TOKTOGUL RESERVOIR G.M. Tostikhin 1, I.V. Tokarev 2, V.N. Shilo 1, А. А. Samsonova 1, B.M. Zhakeyev1 1-Institute of Water Problems and Hydropower, National Academy of Sciences of the Kyrgyz Republic 2- St. Petersburg Branch of the Geoecology Institute, Russian Academy of Sciences Water volume of the Toktogul reservoir is basically formed by flows of the Naryn river and other rivers originating within the area of the Ketmen-Tyube depression. In the northern part of the depression that is more humidified, right tributaries of the Naryn river, such as Uzun-Akhmat, Chychkan, Torkent and Toluk are characterized by considerable length and water abundance. In most cases, their sources are above snow line, and the main catchment areas are located at the heights of 1500-3500 m (Tokarev et al., 2010, Tolstikhin et al., 2010). The rivers mentioned above are characterised by high waters in April-May, when seasonal snow thaw in mountains; according to a standard point of view, the peak associated with thawing of highmountainous snow is observed in June. Table 1 shows average monthly and average annual values of the main rivers runoff. The southern (left-bank) part of the researched area has a poorly developed river system. The biggest tributaries of the Naryn river are Kaindy and Sarygata; their heads are situated on northern dry slopes of the Takhtalyk range. There is no regular waterway on the western side of the range (Kochkor-Tyube mountains). Table 1. Average monthly and annual runoff within the Ketmen-Tyube depression, m3/ sec. (State …, 1985; Resources…, 1969; Resources…, 1967). River Month I II Average volume III IV V VI VII VIII IX XII 9,96 9,06 9,32 23,9 60 Chichkan 5,49 4,98 4,9 10,5 31,7 56,8 43,6 22,2 11,1 7,8 6,55 5,82 17,6 Torkent 3,11 3,11 3,28 8,49 22,2 38,1 23,1 8,67 4,41 4,1 3,83 3,32 10,3 Naryn 136 175 152 261 511 819 711 504 20 XI UzunAkhmat 136 78,8 57,8 33 X 286 15,2 13,3 11,4 28,6 207 147 323 As Table 1 and Fig. 1 show, the main feeding (about 85%) of the Toktogul reservoir comes from the Naryn river. High water periods with water discharge from 800 to 1000 m 3/ sec last from June to July; therefore, the Naryn river plays an important role in forming the chemical composition of Toktogul. 117 800 80 700 70 600 60 500 50 400 40 300 30 200 20 100 10 0 1 2 - Naryn 3 4 0 11 12 5 6 7 8 9 10 Month - Uzun-Akhmat; - Chichkan; - Torkent; Uzun-Akhmat, Chichkan, Torkent,m3/s 90 3/ / Naryn, m3//s/ 3 900 Fig.1. Combined hydrograph of rivers runoff in the Toktogul basin. Over the last decades, a cascade of hydroelectric power plants (Toktogul, Kurpsai, Tashkumyr and Shamaldysai) has been built in the downstream area of the Naryn river. The Toktogul HPP, the largest plant, has a reservoir constructed for long-term runoff regulation, irrigation water supply and hydropower generation. Other reservoirs are important for hydropower generation. Construction of reservoirs, providing seasonal and long-term runoff regulation, is inevitably accompanied by changes in chemical composition of water in tail-waters (in comparison with composition of water in head ranges). In most cases, factors, influencing changes in chemical composition, include (Avvakyan et al. 1994): – evaporation from rОsОrvoirs‟ surface, – reservoir bank transformations and associated mineral salts leakage, – biochemical processes intensification caused by changes in hydrological mode, – growth of environmental pollution caused by economic development of water area and a coastal zone of a reservoir. Results of hydrochemical analyses for 1954 (by thrОО hyНroposts, bОforО thО rОsОrvoir‟s filling) are shown below (Table 2). Data and information given in Table 2 show that downstream the Naryn hydropost, natural composition of water varies substantially but these changes are not strictly proportional. The Naryn hydropost is located 530 km away from a mouth, the Alekseyevka post (the flooded old village of Toktogul) - 150 km, the Uch-Kurgan post - 45 km. However, water mineralization at the UchKurgan hydropost is lower than at the Alekseevka post located upstream the Naryn river. Probably, such phenomenon is associated with tributaries (of the Karasuu and Naryn rivers), which are located between these hydroposts and causing water diluting. It took almost a year and a half (1973 – 1974) to impound the Toktogul reservoir to its maximum operating level; technical conditions of that period were as follows: average long-term discharge of the Naryn river - 324 m3/ sec and water discharge from the reservoir – zero. During 118 these years the hydrological mode of the river (in its downstream areas) changed due to new factors of formation of chemical composition of water in the reservoir (the Report … 1979). Table 2. Macrocomponent composition of water in the Naryn river (before the Toktogul rОsОrvoir‟s filling). Hydroposts and sampling dates Naryn Dates of testing Content 4.06.1954 г. mg/l %-eq. Cations: 16,5 22,6 7,8 22,0 32,2 55,4 56,7 100 Anions: 5,1 4,8 18,3 13,0 146,5 82,2 153,0 Na+ + K+ Mg2+ Ca2+ Sum of cations Cl– SO42– С 3– Estimated mineralization Alekseevka (old pos. Toktogul) 18.05.1954 г. mg/l %-eq. Uch-Kurgan 18.06.1954 г. mg/l %-eq. 19,0 21,3 34,1 74,4 18,0 41,6 40,4 100 12,8 11,2 42,1 76,1 14,4 26,0 59,6 100 14,3 41,1 180,1 219,6 9,6 20,4 70,0 9,8 47,7 135,5 198,3 8,0 28,0 64,0 The forecast of changes in water composition of the Naryn river, adopted during the Toktogul construction, is currently unknown. The forecast, made in the course of engineering-geological studies of thО rОsОrvoir‟s bowl, assumed that water mineralization should increase by on one third – to 0,47 gram/dm3 due to potential growth of anthropogenic pollution and agricultural intensification in a coastal zone (Pleshkov et al. 1979). Studying the question of changes in water composition of the Naryn river caused by the Toktogul HPP, we have used materials of the Naryn hydropost that has been working for more than five decades. About 30% of average annual runoff of the Naryn river run through this hydropost; in Table 3 and Figures 2, 3, data of Kirgizgidromet for 1951-1955 (Kaziev et al., 1964) are compared with data for 1987-1990. Table 3. Macrocomponent composition of water in the Naryn river (according to Kyrgyzhydromet data) Index + Na + K Observatio n periods + %mg/l eq. 2+ Mg Ca Cl– %mg eq. /l for 1951-1955 high water 14.5 23.3 6.4 19.6 30.8 57.1 5.9 6.3 for 1987-1990 low water 25.2 24.8 14.0 26.4 43.2 48.8 9.4 5.9 high water 14.3 22.6 7.9 24.2 29.3 53.2 6.1 6.3 average long-term 17.1 23.4 8.6 22.5 34.8 54.1 8.3 11.3 compositio n mg/l %eq. 2+ mg/l %eq. 119 SO42– mg/l %eq. HCO3– mg/l %eq. Estimat Naryn ed river mineral discharge ization , m3/ sec 24.2 18.5 124.0 75.2 143.5 168,5 48.1 22.6 194.2 71.5 237.0 31.6 24.1 115.8 69.6 146.1 36.8 24.0 125.8 64.7 168.5 160 140 250 ) b) 200 120 150 80 100 60 40 50 20 0 ) – 1951-1955; ) – low water; TDS HCO3 SO4 Cl Ca Na + K TDS HCO3 SO4 Cl Ca Mg Na + K 0 Mg Content , mg/ll 100 – 1987-1990 – ; high water – average long-term composition Fig. 2. Comparison of macrocomponent composition of water of the Naryn river at the Naryn hydropost for two periods: 1951-1955 and 1987-1990. (data provided by Kirgizgidromet) Comparing two periods of high water for different years, it is possible to draw a conclusion that in terms of mineralization value, sodium content + potassium and chlorine, differences do not exceed 1-3 % limits. The difference in concentration of sulphates (23 %), magnesium (19 %), hydrocarbonate (7 %), calcium (5 %) is basically caused by differences in methodology used during the last 40-50 years to analyse water samples. The existing data and information allow to maintain that under the influence of natural factors, water composition of the Naryn river has remained practically unchanged over the last 40-50 years (in the upper part of the Naryn river basin). The revealed changes in chemical composition of water in the middle part of the Naryn river basin (after the construction of the Nizhne-Naryn cascade of HPPs) are consequences of hydraulic engineering construction. To evaluate the influence of Toktogul on changes in water composition of the Naryn river, two sites were chosen: Uch-Terek (head range of the reservoir) and Tashkumyr-verkhnii (this site is located downstream the Kurpsai HPP, the Karasu river mouth - right). Table 4 shows the comparison of macrocomponent composition of water at these two sites for a year characterised by water abunНanМО (aftОr thО rОsОrvoir‟s МonstruМtion). As Table 4 shows, a zone between the two chosen sites has the lowest chlorine content. This phenomenon is caused by an increased diluting role of side tributaries of the Naryn river; these tributaries are formed within a territory characterised by magmatic rocks, weak chloride combinations and solutions as well as with well washed out sedimentary rocks of the Palaeozoic period and metamorphic formations of the pre-Palaeozoic and Paleozoic age. As a whole, there are no fundamental changes in macrocomponent composition of the Naryn waters under stationary hydrological modes of the Toktogul and Kurpsai reservoirs. This implies that the quality of water released from Toktogul is not affected. Data and information of hydrochemical studies for 2007-2009 obtained at the Uch-Terek hydropost confirm this conclusion (Tables 5, 5a, 6). 120 Table 4. ComparativО МharaМtОristiМs of thО Naryn watОrs by hyНroposts “UМh-TОrОk” anН “Tashkumyr-vОrkhnii” for 1987. Index of composition р Cl–, mg/l SO42–, mg/l Mg2+, mg/l Ca2+, mg/l Solid residue Uch-Terek Upper Tashkumyr 7,20†8,12* 7,67 7,1†41,8 18,2 30,3†92,2 48,3 6,1†18,5 12,0 29,6†63,1 44,1 130†328 215 7,42†8,02 7,85 5,13†17,7 12,2 26,9†72,0 43,0 10,6†20,3 12,5 20,0†48,1 39,6 136†239 219 Naryn river 3 discharge, m / sec Character of changing of average values +2,7 % –32 % –11 % +4,1 % –26 % +2 % 479.61 * – numerator- variation interval, denominator- average annual; Table. 5. Chemical composition of surface waters of the Naryn river at the Uch-Terek hydropost in 2007-2009. 426.00 303.00 303.00 303.00 303.00 209.00 198.00 250.00 р 334 315 321 334 367 329 379 375 7.8 8 8 7.8 7.8 7.9 7.9 7.6 3.5 3.3 3.3 3.5 3.8 3.3 4.4 3.8 Water oxidizability 20.08.07 27.08.07 03.09.07 10.09.07 17.09.07 24.09.07 19.04.08 27.09.09 Chemical composition of water, mgram/l Mineralizati on General water hardness Discharge of the Sampling Naryn date river, m3/ sec Са2+ Mg2+ Na+ K+ Cl– SO42– HCO3– NO3– 0.16 1.52 0.56 1.36 1.04 0.24 0.56 0.48 48 44 44 47 54 58 58 61 13 13 13 14 13 12 18 9 16 15 15.4 16 15.6 16 29.6 21 1.8 1.8 1.8 1.8 1.8 1.8 2.4 2.1 18 16 18 16 7 18 37 16 64.6 65 65.8 63.8 10.3 62.6 97.5 67.9 134 122 125 140 126 134 168 171 3 4 4 1 1 3 2.7 3.5 Table 5a. Comparative characteristics of some macrocomponents of chemical composition of water in the Naryn river at the Uch-Terek hydropost in 1954–2009. Macrocomponents pH Ca2+ Mg2+ Cl– SO42– Discharge of the Naryn river, m3/ sec 1954 7.7 34.1 21.3 14.3 41.1 1987 7.7 44.1 12.0 18.2 48.1 1990 7.6 39.7 11.4 465.15 479.61 Observation years 1991 1992 38.5 13.6 44.0 17.2 52.2 64.9 72.4 2007 7.8 47.0 14.0 16.0 63.8 414.73 339.29 382.64 312.00 121 2008 7.9 58.0 18.0 37.0 97.0 289.00 2009 7.6 61 9.0 16 67.9 Table 6. Comparative characteristics of some macrocomponents of chemical composition of water (the Naryn river at the Uch-Terek hydropost, and upstream walls and tail-waters of the Toktogul and Kurpsai dams for 2007–2009). Sampling site the Naryn river at the Uch-Terek hydropost Toktogul dam (upstream wall)* Toktogul dam (tail-water)* Kurpsai dam (upstream wall)* Kurpsai dam (tail-water)* * Cl–, Mg/l SO42–, Mg/l HCO3–, Mg/l 18.0 62.6 134.0 29.6 20.0 21.0 37.0 26.0 16.0 97.53 73.25 67.9 168.0 149.0 171.0 13.5 23.5 24.3 75.3 156 39.1 12.8 0.46 5.0 51.85 101.3 spring 2008 spring 2009 autumn 2009 average 53.1 64.13 61.0 10.94 9.73 9.0 3.45 1.13 21.0 11.94 5.6 16.0 65.43 71.6 67.9 122.0 141.5 171.0 54.3 10.6 6.5 9.6 64.2 134 autumn 2007 54.1 3.65 13.1 6.67 58.8 1.128 spring 2008 spring 2009 autumn 2009 average 60.12 52.1 44.89 2.43 23.1 15.56 18.63 7.98 13.36 13.55 10.38 12.07 76.95 83.12 64.61 120.8 170.8 107.36 52.8 11.2 13.3 10.7 70.9 100 autumn 2007 44.1 13.62 0.39 10.0 49.5 115.9 spring 2008 spring 2009 autumn 2009 average 48.09 45.09 38.08 10.9 14.2 21.89 11.67 30.64 0.9 8.07 7.34 6.67 49.4 82.3 51.4 158.6 164.7 148.8 43.8 15.2 10.9 8.0 58.2 147 autumn 2007 48.1 8.76 1.89 8.34 50.6 109.8 spring 2008 spring 2009 autumn 2009 average 18.1 50.0 44.09 10.94 15.8 12.16 7.36 18.1 13.59 11.3 5.47 8.67 72.0 79.4 45.7 109.8 158.6 152.5 40.1 11.9 10.2 8.4 61.9 133 Са2+, Mg/l Mg2+, Mg/l autumn 2007 58.0 12.0 spring 2008 spring 2009 autumn 2009 average 58.0 53.0 61.0 18.0 15.0 9.0 57.5 autumn 2007 date Na+, Mg/l - Analysis was made by the In-Situ Observation Laboratory of the Cascade of Toktogul HPPs Table 6 “Comparative characteristics of some macrocomponents of chemical composition of water of the Naryn river at the Uch-Terek hydropost for 1954-2009”. 122 Reservoir bank transformation processes exert some influence on chemical composition of the Toktogul waters. During the Toktogul impoundment, evaporite horizons containing halite (NaCl), mirabilite (Na2SO4 * 10 H2O), thenardite (Na2SO4) and astrakhanite (MgNa2 (SO4)2 * 4 H2O) have been flooded (Kaziev et. al., 1964; Kovalev, 1972, 1985). The Shamyshkalata rock salt deposit, located in the middle, right-bank part of thО rОsОrvoir‟s watОr arОa is МurrОntly unНОr development. Among important observations obtained undet the project is high salinity of temporary waterways flowing down from the Shamyshkalata mountains (Fig. 4) into the Toktogul reservoir during rainy seasons in winter (Table 7). Mineralization of temporary waterways, flowing through the canyon of the Toskol river and the Chon-KОn Мanyon, rОaМhОs M ≈ 267-302 g/dm3. Fig. 4. Saline mountain of Shamshylata located in the northwest of the Toktogul reservoir Table 7. Results of hydrochemical analysis of surface waters flowing through the rock salt deposit of Shamyshkalata, November 2009 (mg/ dm3) Sampling site Mouth of a temporary stream located in the Chon-Ken canyon Underground waters from a prospect hole 1,2 m deep, located 10 m from a shoreline in the reservoir Waters from a temporary stream located in the Chon-Ken canyon, 1km from a mouth Waters from a temporary stream located in the Chon-Ken canyon, 0,5 km from a mouth Right tributary of the Toskol river Toskol river Left tributary of the Toskol river Solid residu e NO3N Fе 55 <0.3 0.54 0.12 28360 12000 40 0.04 0.7 1.1 38230 225 320.6 2822 163956 17000 90 <0.3 0.43 0.2 30174 0 215 300.6 2533 159525 19000 45 <0.3 0.44 0.11 29885 0 185 460.9 3678 132938 24300 70 <0.3 0.22 0.27 < 0.5 60.1 20.5 24.8 96 4.7 0.04 26700 0 0.02 0.32 390 < 0.5 80.2 4.8 60.3 225 4.1 0.03 0.197 0.51 714 К 235 Ca Mg Cl SO4 280.6 2364 177250 15500 18.3 340.7 627.1 123 Mn F 30029 0 A geological description of sediments composing mountains was analysed. The analysis done shows that here the basic share of geological formations is presented by clay differences of rocks with low hydraulic permeability. Exits of stone salt on surface are observed on rather small areas, basically on an opencast mine. Despite this fact, the analysis made allows to assume that the main wash-out of easily soluble combinations takes place practically along the whole area of the reservoir and is directly caused by dissolution of crusts and salt exudates. Salt accumulation in near surface parts of an open-cast is apparently caused by water evaporation in dry seasons (when capillary moisture joins surface evaporation. Experimental data and information on salinity of water flowing down from the ShamshykalAta mountains were used to evaluate of the balance of salt intakes from the catchment surface to the Toktogul reservoir. The potential increase in mineralization of thО rОsОrvoir‟s water was calculated. ThО balanМО moНОl „prОМipitation-evaporation-runoff‟ offОrОН by V.A. KuzmiМhОnok has thО runoff value of ε = 50-100 mm/year for the area of the Shamyshkalata mountains. An area of the catchment of temporary waterways running through the Toskol river canyon and Chon-Ken, where salt washout is observed, makes up S = 11.5 km2. According to Table 7, the average mineralization of temporary waterways is 292 g/l. Cumulative runoff of rivers flowing into the reservoir is about 12×109 m2/year. The dependency calculated by V.A. Kuzmichenok can be used to determine water volume in Toktogul at different water levels. Results of calculations are given in Table 8. Table 8. Estimation results of potential increase in water mineralization in the Toktogul reservoir that, as experimental information shows, might be caused by salt-washout from catchments of temporary waterways flowing into a canyon of the Toskol river and the ChonKen canyon (Shamyshkalata mountains) Total area of the catchment of temporary waterways in the Toskol river canyon and Chon-Ken, m2 Average salinity in the Toskol river canyon and Chon-Ken, kg/m3 Runoff depth, m/year Runoff volume from the catchment surface (for the area of the Toskol river canyon and Chon-Ken), m3/year Salt produced by runoff, kg/year Average annual flow of rivers, m3/sec 11500000 292 0,05 0,1 575000 1150000 167900000 335800000 UzunAkhmat 28,6 Naryn 323 Cumulative average annual flow of rivers, 379,5 m3/sec Cumulative average annual volume of flow 11967912000 into the reservoir, m3/year Level of water surface in the reservoir, m 850 m 900 m 3 Water volume in the reservoir, m 7715000000 19548000000 Period of water cycle in the reservoir, years 0,64 1,63 Increase in mineralization of water in the 0,022 0,017 reservoir, without inflow by rivers, kg/m3 Increase in mineralization of water in the 0,009 0,011 reservoir, with inflow by rivers, kg/m3 124 Chychkan Torkent 17,6 10,3 Thus, according to calculations (Table 8), a potential increase in mineralization of the rОsОrvoir‟s watОr НuО to salt washout from the surface of catchments located in the Shamyshkalata mountains varies between 10-20 mgr/l). Taking into account high density of salt water coming from the Shamyshkalata Mountains, it shoulН „sink‟ right aftОr its Оntry to the water area forming watОr lОns in thО rОsОrvoir‟s bottom. Data and information of field works conducted in 2007-2008 show that water mineralization in this “lОns” should be by 30-60 mg/l higher in comparison with the whole reservoir. The last opinion is confirmed by the experimentally discovered increase in water salinity in deep parts of the reservoir; this increase was recorded during field works in 2007-2008, whОn thО rОsОrvoir‟s watОr lОvОl was not very low. During the 2008-2009 winters, a large volume of water was discharged from the reservoir; therefore, a period of water cycle considerably decreased. According to an approximate evaluation, the period of water cycle in the reservoir (at its present water level) is six months (Table 8). This period is considerably less than a period between two rainy seasons taking place once a year in winter time. Correspondingly, the whole volume of water together with salts, entered to the reservoir during the 2008-2009 winter months, was discharged, and the lens of significantly salt waters should disappear. Measurements data and information, obtained in October 2009, confirm this assumption (Fig. 4). 0 20 0 50 Concentration of species, mg/l 80 40 60 100 120 0 5 10 15 Deep, m 20 25 30 35 40 45 50 100 200 150 250 300 TDS, mg/l – Ca, – Mg, – Cl, – SO4, – NO3, – TDS, mg/l Fig. 4. Distribution of cumulative mineralization and content of some components by the reservoir’s depth during the period of 6-9 October 2009. In addition to the performed calculations of changes in water mineralization in the reservoir, the following additional remark should be made. Since the calculations do not consider inflows of 125 underground waters, in a near bottom part of the reservoir, an increase in mineralization will be apparently higher than 30-60 mg/l. Salt intakes (coming with underground waters) is possible within a zone, where Shamshykalata mountains border with the reservoir. However, these mountains are characterised by clay geological profiles and small amount of precipitation. In aggregate, these two circumstances impede the formation of significant underground water runoff from the given area. Additional salt intakes (coming with underground waters and flowing into the reservoir) should be observed in the Uzun-Akhmat valley. For example, we recorded the increased mineralization of underground waters (M = 1-4 g/dm3) at the Chon-Aryk well (Table 9); this level of mineralization was observed before (Ramankulov et al. 1972, Chepkov et al. 1988). Simultaneously, rocks of this area are characterised by rather good permeability (kf = 0.3-0.5 m/ day); this phenomenon creates favourable conditions for inflow of saline underground waters into the reservoir. Table 9. Results of chemical analysis of underground waters, mgram/ l. Sampling site Chon-Aryk well Dolon-Bulak spring Kara-Bulak spring Well in the Kyotyormyo village Torkent spring Spring in the KaraDjigach village Naryngidrostroi spring Sampling date 25.10.1986 18.04.2008 26.09.2009 15.04.2008 19.04.2008 28.04.2009 30.08.1969 19.04.2008 28.09.2009 17.04.2008 28.09.2009 18.04.2008 28.09.2009 02.11.2009 16.04.2008 27.09.2009 Mineralization, gram/l 946 1774 1298 1231 515 490 410 476 458 472 375 301 280 222 1220 1234 Ca Mg Na Cl SO4 HCO3 78 109 103 152 78 81 52 44 41 70 63 52 52 38 152 152 57 78 73 26 19 17 8 9 9 13 10 7 7 12 26 25 220 310 203 135 16 15 44 62 68 27 17 9 6 134 48 72 525 533 69 12 10 18 21 21 25 22 5 7 4 69 60 266 397 96 491 87 77 61 103 98 49 32 20 20 8 485 478 42 156 146 226 244 247 177 174 171 241 196 174 165 144 223 268 This article explores interconnections between separate components using data of the last underground water sampling. Results of a pair correlation analysis are given in Table 10. Since a range of variations is quite large, all measured parameters are statistically closely connected with each other. In this particular case, these connections are considered fictitious; fig. 5 demonstrating spreading graphs indicates the fictitious nature of the connections in focus. Table 10. Results of a pair correlation analysis of results of chemical composition detection of underground water samples collected during the periods of 26-29 September and 7-8 October 2009. Ca Mg Cl SO4 NO3 TDS Ca 1 Mg 0,91 1 Cl 0,85 0,96 1 SO4 0,96 0,98 0,93 1 NO3 0,92 0,95 0,93 0,95 1 TDS 0,85 0,97 1,00 0,94 0,93 1 126 Fig. 2. Spreading graphs based on results of detection of chemical composition of underground waters For accurate interpretation of the obtained data, only samples with small aggregate concentrations of components (TDS < 1 gram/l) were used for calculation of statistical connections. Table 11 shows results of a pair correlation analysis. For research selection, a coefficient of pair correlation (r = 0,37) at a confidence level (p < 0,05) is important. Table 11 shows that pairs of sulphate-chloride (rCl-SO4 = 0.98), TDS-chloride (rTDS-Cl = 0.97), TDS-sulphate (rTDS- SO4 = 0.98) are characterized by statistically close correlation. Such close correlation can be explained by the fact that these components of chemical composition are predominately formed with the help of the same mechanism - dissolution of readily soluble salts by precipitation. As a result, these pairs cannot be used for genetic interpretation of contributions coming from other sources of chemical composition formation. Table 11. Results of a pair correlation analysis aimed at determining chemical composition of underground water samples for a selection, when TDS < 1 g/l Ca Mg Cl SO4 NO3 TDS Ca 1 Mg 0,12* 1 Cl 0,09 1 0,49 SO4 0,14 1 0,51 0,98 NO3 0,15 0,36 1 0,54 0,58 TDS 0,20 1 0,48 0,97 0,98 0,63 * r = 0,37 correlations are significant at p < 0,05. Spreading graphs for a selection of chemical analyses of underground waters, when TDS < 1 gram/l are constructed for all pairs of measured parameters shown on fig. 3. 127 Fig. 3. Spreading graphs based on results of detection of chemical composition of underground water samples for a selection, when TDS < 1 g/l. Spreading graphs for pairs of Cl-Ca, SO4-Ca, TDS-Ca point to a three-component mixing. To some extent, this phenomenon is confirmed by spreading graphs for pairs Ca-Mg, NO3-Ca, NO3-Mg, NO3-Cl и NO3-SO4. A high НОgrОО of points‟ sprОaНing in pairs Мontaining nitratО Мan bО assoМiatОН with agricultural activities and domestic-fecal dumping. Spreading graphs for pairs of Cl-Ca, SO4-Ca, TDS-Ca have quite specific shape that forms two divergent „mustaМhОs‟. A graph lОg, whiМh goОs up for Cl and SO4 is associated with supply of readily soluble components from the Shamyshkalata Mountains or other parts of the catchment containing evaporates. A graph leg with relatively low and almost constant concentrations of Cl and SO4 is associated with efflorescence and drain from the catchments. Observations and evaluation calculations have confirmed the assumption that the considerable share of changes in water quality of Toktogul is associated with surface and underground flows that wash away readily soluble combinations. The Shamyshkalata Mountains and the Uzun-Akhmat valley are the main areas characterized by such washout. In Shamyshkalata, surface washout predominates, while in the valley, salts flow into the reservoir together with underground flow. A surfaМО МomponОnt МontributОs to thО inМrОasО of thО rОsОrvoir‟s minОralization at 20-60 mgr/l The share of underground component is evaluated with the use of a numerical model of the Toktogul catchments. The main share of chemical runoff as well as water quality in Toktogul is associated with normal chemical efflorescence and runoff from the catchments The conducted studies, aimed to evaluate water composition in the Toktogul reservoir, have demonstrated that the construction of Toktogul strengthened self-cleaning ability of the regulated 128 part of Naryn by the following components: nitrates, phosphorus, silicon, mineral oil, biochemical consumption of oxygen and demand of chemical oxygen. It was revealed that in downstream parts of the Naryn river, traces of DDT, obviously observed in the early 80s and caused by wash-out from agricultural lands of the Ketmen-Tyube depression, disappeared. Water clarification in the reservoir is considered as a positive fact, from the point of view of drinking water supply, and as a negative fact for irrigation water supply (because nutritious components of irrigation water are lost together with water suspensions). Reference Avvakyan A.B., Kocharyan A.G., Maidanovsky F.G. The influence of reservoirs on chemical runoff transformation. – MAIK “Nauka” - WatОr rОsourМОs, volumО 21, № 2, 1994. – pp. 144-153. The State water cadastre. Volume XI, the Kirghiz Soviet Socialist Republic (SSR). – Frunze, 1985.– p. 276. Kaziev К., Osmonov I., Asanaliev Z. Hydrochemical characteristics of surface waters within the area of the projected Toktogul reservoir and salinity forecast of its waters//Interim report № 21 «ChОmiМal composition of waters of Kirghizia: thОir usО anН protОМtion». FrunzО: KGGF, 1964. – p. 95. Kovalev V.M. The influence of rock salt deposits of Shamyshkalata on water salinization in the Toktogul reservoir//In Hydrogeology and engineering geology of arid zones of the USSR. – Issue 6. Laws of formation of underground waters and their resources. – : Nedra, 1972. – p. 118–125. Kovalev V.M. Forecast of the Toktogul reservoir bank transformations //In Hydrogeology and engineering geology of the Kirghiz Soviet Socialist Republic. – Frunze: Ilim, 1985. – p. 40–53. Methodical foundations for assessment and regulation of anthropogenic influence on the quality of surface waters. / Edited by A.V.Karausheva. – L: Gidrometizdat, 1979. p. 214. The report on complex studies of the Toktogul reservoir conducted in June 1979 by the Issyk-Kulsky biological station of the Academy of Sciences the Kirghiz SSR. Pleshkov Ya.F., Mukhopad V. I. Questions of engineering hydrochemistry and water protection. – L: Gidrometizdat, 1979. – p. 224. Ramankulov B.A., Matychenkov V. E. The report on search works in the Toktogul area conducted in 1969-1971 and aimed to study sources of water supply for settlements to be displaced from a zone of thО rОsОrvoir‟s flooding. – Frunze: КГГФ, 1972. Resources of surface waters of the USSR. Volume14./ Edited by I.A. Ilin. – L: Gidrometizdat, 1969. – p. 438. Resources of surface waters (basic hydrological characteristics) / the Syr Darya river basin, Volume 14, issue 1. – Gidrometeoizdat, 1967. Chepkov V. I, Reshetnikov S.V. Results of detailed searches of underground waters for water supply of settlements located in the Toktogul raion of the Talas oblast of the Kirghiz SSR. The report of the Kalininsky hydrogeological team on works conducted in 1984-1988 in the KetmenTyube depression. – Bishkek: KGGF, 1988.– p. 140. 129