The Caspian Sea basin is a huge and unique geographical feature. It has not yet been fully investigated, so it is still of interest not only to tourists, but also to scientists. It is said that once upon a time the Caspian Sea was even larger than it is now. At one time, the Aral Sea, which now has become very small, may have been a single system along with the Caspian. But this is only a hypothesis. This article will discuss which basin the Caspian Sea belongs to, what are the environmental problems of this region and how to solve them.
General information
The Caspian Sea is a huge water reservoir located within Central Asia. It is also considered the largest lake (although this is not geographically true), but still it is the sea. This is the only inland sea of the Earth. Millions of tourists come here every year. This reservoir is considered as a single ecosystem. Everyone asks: to which basin does the Caspian Sea belong? Answer: to the basin of internal flow. The fact is that it does not have access to the oceans.
The reservoir has a huge amount of different resources, including minerals. Some unscrupulous people regularly collect minerals from here in unmeasured quantities, and also catch too much fish. Poaching can harm the ecosystem as a whole. To avoid this, environmentalists are trying by any means to influence the stop of this process.
Swimming pool
The area of the Caspian Sea inland runoff basin is 392, 000 square kilometers. It is equal in size to two such states as Great Britain. Here are waters of high salinity. The total volume is 78, 640 km 3. The facility itself is located at the junction of Europe and Asia and washes the coasts of countries such as:
- Turkmenistan;
- Kazakhstan;
- Iran;
- Azerbaijan;
- Russia.
The sea has a unique flora and fauna. Also here formed the crust of the oceanic type. This is due to the fact that the current Caspian Sea is part of the very ancient Tethys Ocean, which included not only the Caspian basins, but also the Aral and Black Sea with the Sea of Azov.
Relief
The basin of the Caspian Sea to which ocean belongs? Answer: this sea does not belong to any ocean, since it is a closed waterway.
The Caspian is a complex and specific reservoir that has individual characteristics. There is no such relief anywhere on earth. Despite the fact that now the area is 392 thousand km 2, this is still small, since about 90 years ago its area was even larger - as much as 422 thousand km.
In the north is the Caspian lowland, and in the south of Mount Elbrus. In the western part you can see the Greater Caucasus, and in the south-west the foothills of the Talysh mountains and the Kurinsky and Lankaran lowlands.
The length of the entire coastline is approximately 6500-6700 kilometers. The average depth is about six hundred meters.
There are ten small bays in the Caspian. One of the most famous is Kara-Bogaz-Gol. It is a natural desalination plant of the Caspian Sea. The water level in the Caspian Sea was constantly falling, so the decision was made to separate the Kara-Bogaz-Gol Bay with a dam, as a result of which it completely dried up in three years and almost turned into a salt desert. But then the salt began to be carried by the winds and polluted the soil. As a result, many crops were affected. After that, in 1984, it was decided to remove the dam and put in the water supply, which helped to extract mineral salt. To date, the bay is almost completely restored, and the Caspian is again with normal water levels.
What is unique?
Here are unique climatic features that are not found anywhere else on Earth. The sea is located within different climatic zones: continental in the northern part, temperate in the middle part and subtropical in the southern part. Most of the reservoir is in a temperate climate. The average air temperature in winter is within ten degrees of frost. In the summer, this figure is within thirty degrees of heat. The maximum heat of +44 degrees was recorded in the summer on the east coast.
This sea is considered a partially freezing reservoir. Only the northern part of the Caspian freezes in winter. The average ice thickness here is from sixty to ninety centimeters. Freezing lasts from November to March. If the winters are warm, then there may not be any ice cover at all.
The main problem is sea level fluctuations. It is constantly changing, either up or down. Scientists say that this has been happening throughout the history of the pond. Now the level has stabilized for some time, but after a while it will constantly change again, which can cause problems for local residents.
Which ocean basin does the Caspian Sea belong to? The Caspian is very sensitive to climate change, since it does not belong to the basin of any of the oceans.
According to archeology and written sources, a high level of the Caspian Sea is recorded at the beginning of the XIV century. This confirms that the level of the Caspian Sea has periodically changed. The amplitude of the oscillations reaches fifteen meters. Precipitation, runoff and evaporation strongly affect the water fluctuations of the Caspian during the year.
Which rivers belong to the basin of the Caspian Sea?
As many as 130 rivers flow into the Caspian Sea. Which of them are the largest rivers? The Caspian Sea inland runoff basin includes:
- Upgrade;
- Kuma
- Volga;
- Samug;
- Sulak;
- Ural;
- Volga.
The largest river in Europe and at the same time the largest source of water for the Caspian Sea is the Volga. The river covers almost the entire European part of Russia. She herself is divided into 3 parts. The lower Volga flows into the Caspian Sea. The river has about 150 thousand tributaries, which feed it a little. She transports all this to the Caspian Sea. Recall that most of the entire drain of the Caspian Sea belongs to the Volga.
Volga tributaries receive the bulk of the water from snowmelt and rainfall. The water level in the river decreases significantly in the summer and winter, and increases in spring and autumn.
The Lower Volga freezes in December, and the other two parts - in November. Melting begins in March and April, respectively.
Most of the catchment area of the Caspian Sea belongs to the Volga. The remaining rivers have a much smaller impact on the Caspian.
Scientists have found that such a huge number of large and not very rivers formed a powerful catchment basin of the Caspian Sea with an area of 3.5 million square kilometers.
As much as 80% of the drainage of the Caspian comes from the Volga, Sudak, Terek and Emba. For example, the average annual drain of the Volga is 215-224 cubic kilometers. The rivers of the Caspian Sea basin have a huge impact not only on the reservoir itself, but also on the climate of the region.
Pressing issues
Due to the enormous damage to the economy caused by fluctuations in the level of the Caspian Sea, all countries located in this region are interested in this issue. When water fluctuations begin, then various kinds of entrepreneurs suffer tremendous losses due to the elements.
When the shallowing occurs, then the port cities are not able to accept important cargoes, which disrupts millions of transactions. In the event of a sharp rise in water, agricultural land is flooded, and power lines are damaged or destroyed.
Despite its closeness, the Caspian Sea is quite well saturated with oxygen. The highest oxygen saturation is observed in winter in the Middle Caspian. Recently, there has been an increase in oxygen in the upper layers.
Flora and fauna
Despite the fact that the biological productivity of the Caspian Sea is quite high, it is still poorer in species diversity compared to the Black Sea, although the water bodies are almost identical in area.
1809 species of animals live here, of which 415 are vertebrates. In the Caspian Sea, 101 species of fish are registered, and most of the world's stocks of sturgeon, as well as freshwater fish such as roach, carp, pike perch, are concentrated in it. Pond - the habitat of fish such as carp, mullet, sprat, cutum, bream, salmon, perch, pike. A marine mammal, the Caspian seal, also lives in the Caspian Sea.
The flora of the Caspian Sea and its coast is represented by 728 species. Of the plants in the Caspian Sea, algae predominate - blue-green, diatoms, red, brown, char and others, from flowering plants - zoster and rupiah.
A bit about the relief
North Caspian. In the North Caspian there are many fossilized drying shoals. The Ural furrow is located between the deltas of the Ural River and Mangyshlak Bay. Its depth is from 5 to 8 meters. The bottom of the northern part is slightly inclined to the south. Also covered with sand and shell rock. The waters of the river, which are filled with shallows, flooded estuarine sites.
A distinctive feature of the morphological structure is the presence of relict forms of coasts, channels, and river deltas. Many relict channels are located in the Northern Caspian.
There are very few islands on the Caspian Sea. There are unique seals of the island.
Most of the sea islands of the North Caspian are accumulative formations, such as bars, formed by waves in the periphery of the seabed.
Middle Caspian. The entire territory of the Middle Caspian up to the city of Makhachkala is considered low. But already narrow spurs of the Caucasus Mountains are stretching towards Baku. In the region of Absheron and Dagestan, abrasive and accumulative shores stretch.
Abrasive shores that are found in limestones also prevail here, and in their structure they resemble desert and semi-desert plateaus. In the Middle Caspian, a basin, a continental slope, and a shelf are recorded. The average depth is 20 meters.
South Caspian. Mud volcanoes and tectonic uplifts - this is the relief of the bottom and shelf zone of the South Caspian. The shores of this part are very diverse. In the Baku region, spurs of the south-eastern part of the Caucasus Mountains are observed. Next will be located semi-deserts. Numerous rivers can be observed near the territory of Iran.
Hydrological regime
Since 1985, the observing program has been sharply reduced. This is due to the fact that it is practically impossible to find the true cause of the moisture deficit in the region. Weather information is completely absent in the Iranian coast. Measurement accuracy is almost always low. Therefore, the climatic regime and generally the whole sea is very difficult to explore.
It is very difficult to establish patterns in research. This is because the timing of observations is constantly changing. For example, until 1968, observations at the station in Makhachkala were carried out 4 times a day, then 3, and then again four. The time of observation also periodically changed.
Ship observations are a good source of information. But they cannot be permanent, because they determine the conditions only in those places where the routes of these vessels pass.
Based on this information, we can conclude that now there is no way to study in more detail the evaporation rate in the Caspian Sea.
Environmental problems
These problems are associated with water pollution due to oil production and transportation. The unfavorable situation in the region was aggravated due to a sharp rise in water level at the end of the 20th century. The complete flooding of individual settlements led not only to the loss of food products that grew on this land, but also to the fact that everything was contaminated with oil products. In addition, soil salinization progressed. This triggered an increase in infectious diseases in the region.
The observation system was completely disrupted, as the water level changed dramatically.
Also threatening was the problem of pollution of the sea not only with oil products, but also with a lot of garbage. This affected:
- Change in hydrological regime.
- Change in the hydrochemical regime.
- Natural and socio-economic indicators of the region and related states.
- Heavy metal pollution.
The sea received 90% of its pollution from rivers that flow into the Caspian. The largest percentage of water pollution comes from the Volga and other large rivers such as the Urals.
Water pollution is becoming an increasing problem for five states, since the Caspian Sea has no access to the oceans. All these accumulations of garbage can provoke an environmental catastrophe not only in the Caspian Sea, but also in the basin of the internal flow of the Caspian Sea.
Ways to solve problems
Caspian problems were exacerbated by a number of reasons:
- Water from 1978-1995 rose by as much as 2.5 meters, which is very much for such a short period of time.
- The ecosystem of the Caspian region is now undergoing great degradation and destruction.
- Insufficient financial resources are allocated to combat the consequences.
Physico-geographical features
The Caspian Sea is located 28 meters below sea level. It is the largest enclosed body of water in the world and has about 130 small rivers related to the area of the basin of the internal flow of the Caspian Sea. The sea is called a reservoir because of its enormous size, although it is still considered a lake in its structure and location.
Long-term fluctuations smooth out the Kara-Bogaz-Gol Bay, which was written about earlier in the article. Dead Kultuk and Kaydak also regulate and inhibit sea level fluctuations. These shallow waters evaporate and dry out during the hot season, and fill their reservoirs during the rainy season.
The average depth of the sea is 4-8 meters, and the maximum - 1025 meters (in the South Caspian depression). A depth of 2 meters is reached in the zone of the continental shallow. Shoals here account for 28% of the area, and mainland shallows 69%.
The entire basin of the Caspian Sea from 130 rivers receives about 300 km of cubic water per year. Sulak, Terek, Ural and Volga supply about 90% of all water, as mentioned above. In addition, 2600 rivers flow into the Volga itself.
The total area of the Caspian Sea basin is 1380 km 2. This refers to the catchment area.
Precipitation
The amount of precipitation also greatly affects the formation of the Caspian basin. Since the sea is located in different time and climatic zones, the indicators at two different stations over two years can be very different from each other.
The regime of precipitation of the Caspian Sea directly depends on the interaction of various air masses that pass along this territory. Precipitation is unevenly distributed over the area. The largest number of them falls in the region of humid subtropics in Iran. Scientists count about 1700 millimeters per year. This is the territory of the Lankaran lowland.
In the area of the settlement Oil Rocks, the minimum rainfall is 110 mm per year.
Many people ask themselves: to which basin of the ocean does the Caspian Sea belong? This neutral object, which is both a lake and a sea at the same time, does not belong to any of the ocean basins.
Most of the year warm air masses come to the Caspian Sea. The average rainfall that falls on the water mirror is 180 mm per year, and about 900 mm per year evaporates. The evaporation rate is 8 times the amount of rain and snow. But large rivers do not allow shallowing of the Caspian Sea.
In the cold season from September to March, the Caspian has the highest rainfall.
Surface inflow of river water
The main positive component of the water balance of the Caspian Sea is the river runoff, which prevents it from drying out, as it once happened with the Aral Sea, which is now not even noticed by satellites.
The number of rivers has already been mentioned, but it remains to analyze how the largest of them affect the Caspian and determine its water balance.
After analyzing the course of long-term fluctuations of the main rivers that flow into the Caspian Sea, it was possible to distinguish three characteristic periods, because of which the sea began to change dramatically for the worse.
Until 1950, the state of the Caspian Sea basin was natural, because the reservoir, which was built in the 1930s, had no effect on it. Here, the Rybinsk Reservoir operated from 1932 to 1952.
But when large reservoirs began to be built on the Volga and its large Kama tributary, then the second period of change in the water regime of the world's largest closed water artery began. It was the 1950s and 1970s. During this period, they managed to build 9 huge reservoirs. Now the river flow has become regulated. Such actions led to the fact that the hydrological regime of the Caspian Sea began to change dramatically.
First of all, this is due to the fact that the rivers of the Caspian Sea basin of Russia were the first to regulate, and these are the largest water bodies flowing into the Caspian.
Now, reservoirs are built on absolutely all the rivers flowing into the Caspian, with the exception of the Terek.
But in 1970, the third period began, when the channels of all rivers were regulated. Then it was time for intensive water consumption from rivers for irrigation purposes.
But these three periods have already passed, and the Caspian Sea by 1995 more or less stabilized its water regime. And yet, the sea has received the maximum level of anthropogenic influence in the last decade.
Underground water flow
This component is still the least studied aspect of the water balance in the Caspian Sea. The magnitude of the fluctuation is from 2 to 40 km 3 per year. Scientists say that it is still unclear why there is such a large spread in the passage of water from under the ground. Perhaps there are secret sources of fresh water that no one knows about? Unknown!
But realistically, the quantitative volume of groundwater flow is very difficult to estimate.
Water balance assessment
Scientists say that in the years 1900-1929 a high and stable sea position was observed. This is due to the equilibrium ratio of water balance. But in the period from 1930 to 1941 there was a sharp shortage of water. Further, until 1977, the period of a slight deficit was determined. A sharp rise in water level, which was associated with the regulation of rivers, occurred between 1978 and 1995.
All these problems have been identified through years of research. And it was proved that the sharp level of changes in the water balance, as well as the basin of the Caspian Sea, is associated primarily with anthropogenic activities. And fluctuations in water level occur due to instability in the ratio of the influx of water from the pool and the level of their evaporation, as well as due to the fact that a lot of water goes underground each year for unknown reasons.
Also, tectonic movements have a strong influence on this process. But nevertheless, in the course of research, it was possible to come to this conclusion: all the changes that occurred in the Caspian Sea basin and directly in the reservoir over the past 200 years are provoked by the influence of not only anthropogenic, but also climatic factors.
Legal status
After the collapse of the USSR, the division of the Caspian Sea has long been the subject of unresolved disagreements related to the division of Caspian shelf resources - oil and gas, as well as biological resources. For a long time, negotiations were ongoing between the Caspian states on the status of the Caspian Sea - Azerbaijan, Kazakhstan and Turkmenistan insisted on dividing the Caspian along the midline, Iran - on dividing the Caspian along one fifth of all the Caspian states.
Negotiations on the legal status of the Caspian ended with the signing of the Convention on the Legal Status of the Caspian Sea, held on August 12, 2018 in Aktau. According to the final document, the Caspian Sea remains in the common use of the parties, and the bottom and subsoil are divided by neighboring states into sections by agreement between them on the basis of international law. Судоходство, рыболовство, научные исследования и прокладка магистральных трубопроводов осуществляются по согласованным сторонами правилам. В частности, при прокладке магистрального трубопровода по дну моря требуется согласие только той стороны, через чей сектор будет пролегать трубопровод
Рекреация
Каспийское море славится своими песчаными пляжами и лечебными грязями. Если вы хотите посетить уютное, но комфортное место возле скал, то многие туристы советуют небольшой город Актау с населением 300 тысяч человек.
Несмотря на высокую развитость курортов, Каспий все равно проигрывает Кавказскому побережью Черного моря. Туркменистан не может принимать на Каспийском море большое количество туристов из-за политической изоляции, а в Иране законы шариата. Поэтому оптимальный вариант - Казахстан, в районе Актау или других небольших городках.
Бассейн океана Каспийского моря очень разнообразен. В будущем, возможно, данная местность станет главным курортным центром мира.
