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THE FACE OF BAIKAL - WATER ©
Budget |
Baikal is a drainage lake. 544 rivers bring their waters
to it. One river, the Angara, flows out of it.
The hydrological budget of the lake,
as one would suppose, has both input and output. The average hydrological budget for the
period 1901 - 1971 has been calculated by A.N.Afanasiev.
The input part of the budget coming via the tributaries is 58.76 cubic kilometres
(82.7%), via precipitation - 9.29 cubic km. (13.1%), and condensed moisture - 0.82
cubic km. (1.2%) In total this is 68.86 cubic kilometres of water. |
Water balance of Lake Baikal for 1901 - 1971
(according to A.N.Afanas'ev, 1976)
| Elements of inflow |
Layer, mm |
Volume / km3 |
% |
| Percipitation |
296 |
9,29 |
13,1 |
| Condensation at the lake's surface |
27 |
0,82 |
1,2 |
| Inflow tributaries |
1870 |
58,75 |
82,7 |
| Underground |
68 |
2,30 |
3,0 |
| TOTAL |
2261 |
71,16 |
100 |
The output part of the budget comprises the volume of flow from the
lake, which is 60.39 cubic km. (84.8%), and the amount of evaporation - 10.35 cubic
km. (14.6%). In all the output was 70.72 cubic km. The amount by which the
volume of the lake's water was increased after the building of the Irkutsk
Hydroelectric Power Station and the raising of the level of the lake by 1.4 metres
was added to this, that is, 0.44 cubic km. As a result the output increased to 71.16
cubic km.
Water balance of Lake Baikal for 1901 - 1971
(according to A.N.Afanas'ev, 1976)
| Elements of outflow |
Layer, mm |
Volume / km3 |
% |
| Lake's outflow |
1916 |
60,39 |
84,8 |
| Evaporation |
331 |
10,33 |
14,6 |
| Outflow |
2247 |
70,72 |
99,4 |
| Increase of the lake's level |
14 |
0,44 |
0,6 |
| TOTAL |
2261 |
71,16 |
100 |
The input therefore turned out to be less than the output by 2.30 cubic km. This
difference could have been the result both of error in the calculations and the
unaccounted for flow of underground waters into the lake. A.N.Afanasiev put this
figure down to underground waters entering Baikal.
The question of the relationship between Baikal's waters and the underground
waters of the surrounding territory has been studied by hydrologists. From the
northeast, east and southwest, Baikal is surrounded by basins (the Barguzin,
Verkhnaya Angara, Tunkinsky and others) in whose rocks there are underground
confined (artesian) waters. The question is - do these feed Baikal, or, on the
contrary, does Baikal feed them? The hydrologists A.I.Efimov and
R.Y.Koldysheva think that this question has been insufficiently studied.
Nevertheless, they suppose that in the valley of the Selenga, down to a depth of
250 metres, there is a flow of underground waters into the lake. Below this level
an outflow of Baikal's waters occurs in the direction of the nearest artesian basins.
As has already been mentioned, V.A.Golubev determined the input of deep
underground waters. Only a rough estimate can be given for their volume. Golubev
believes that in North Baikal approximately 350 litres of water per second enter
the lake from underground, and in Central Baikal, about 2001 per sec.
The lake's hydrological budget, just like its level, is not stable, not constant.
Shortly before the lake is freed of ice, in April, the volume of water and the level
begins to rise gradually. The reason for this being that the river waters increase.
This increase can be observed throughout the summer and it reaches its climax at
the end of September, beginning of October. From then on the volume and level
gradually drop, reaching a minimum in April. The highest level of water in Baikal
was recorded in 1869, and the lowest in 1904. The amplitude of fluctuation in level
reached approximately 2 metres. Today, the level of water in the lake is regulated
by Irkutsk hydroelectric power station, which had raised it by about 1.4 - 1.5
metres.
The level of water in the lake depends on the flow in rivers, and this flow is
subject to fluctuation cycles over periods of years. These cycles have their effect
on the budget of Baikal's waters and low and high periods can be observed.
The water level near the shore is influenced by winds that cause surges and
drops. During these the amplitude of change in level can reach 0.3 m. Changes in
level of up to 0.15 m can also occur as the result of inertial fluctuations, or seiches.
And very small changes of up to 0.03 m. are brought about by tidal phenomena.
Tides of the kind that occur in seas and oceans simply do not exist in Baikal.
In the last century a network of marks (notches in cliff faces) were made at
Baikal with the help of which it has been possible to observe changes in the lake's
level. It all started in 1869 when there were abundant rains in the Zabaikalye area
raising its level dramatically. A.P.Orlov suggested marking such high rises in
water level by notches in cliff rocks. The first notches and first observations of the
level using them were made by B.Dybovsky on the cliffs of Cape Shaman, not far
from the settlement of Kultuk. A few years later, I.D.Chersky, while making a
journey around Baikal by boat, cut out 14 notches around its perimeter. These
were horizontal indentations in the stone 20 cm long and 2 cm deep. The idea was
to make observations of the water level with the help of these notches. However,
measurements that were made subsequently showed the margin of error in the
measurements to be very great, so it is extremely difficult to use this method to
draw any serious conclusions. Today the notches in the cliffs are mainly of
historical interest. They are monuments to the scientific investigations and
investigators of the past. |
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